FN Thomson Reuters Web of Science™
VR 1.0
PT J
AU Steffen, K
Nghiem, SV
Huff, R
Neumann, G
AF Steffen, K
Nghiem, SV
Huff, R
Neumann, G
TI The melt anomaly of 2002 on the Greenland Ice Sheet from active and
passive microwave satellite observations
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID REGIONS
AB Active and passive microwave satellite data are used to map snowmelt extent and duration on the Greenland ice sheet. The passive microwave ( PM) data reveal the extreme melt extent of 690,000 km 2 in 2002 as compared with an average extent of 455,000 km 2 from 1979 - 2003. A statistical analysis of the melt time series affirms an increased melt extent earlier in the melt season. The QuikSCAT (QSCAT or AM) analysis for 1999 to 2004 confirms the extreme melt situation in 2002. QSCAT data show a significant increase in melt season length over several areas in 2003. SSM/I and QSCAT melt data reveal that the later detects melt earlier and is more sensitive to surface melt. QSCAT detects an earlier stage of melt and SSM/I detects a later stage of melt. The SSM/I XGPR melt extent is approximately confined to the QSCAT melt areas experiencing 2 weeks or more of melting time.
C1 Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Steffen, K (reprint author), Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA.
EM koni@seaice.colorado.edu
RI Steffen, Konrad/C-6027-2013
OI Steffen, Konrad/0000-0001-8658-1026
NR 8
TC 72
Z9 74
U1 1
U2 13
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 21
PY 2004
VL 31
IS 20
AR L20402
DI 10.1029/2004GL020444
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 867XJ
UT WOS:000224875800002
ER
PT J
AU Bandfield, JL
Rogers, D
Smith, MD
Christensen, PR
AF Bandfield, JL
Rogers, D
Smith, MD
Christensen, PR
TI Atmospheric correction and surface spectral unit mapping using Thermal
Emission Imaging System data
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
DE atmospheric correction; infrared spectroscopy; Mars
ID MARS GLOBAL SURVEYOR; MULTISPECTRAL IMAGES; SPECTROMETER DATA; TES
OBSERVATIONS; INFRARED IMAGES; MGS-TES; ABUNDANCE; DUST; ROCK;
DECONVOLUTION
AB Three techniques are described for the extraction of surface emissivity and compositional information from Thermal Emission Imaging System (THEMIS) images. Synthetic images were constructed with different atmospheric properties and random and systematic errors to estimate the uncertainty in the retrieved surface emissivity. The three techniques are as follows: ( 1) A constant radiance removal algorithm determines and removes a constant radiance from atmospheric emission as well as systematic calibration radiance offsets. ( 2) Surface emissivity retrieval uses low-resolution Thermal Emission Spectrometer surface emissivity data to determine atmospheric properties for an image that can be then applied to individual THEMIS pixels. ( 3) A spectral unit mapping algorithm determines spectral end-member concentrations using a deconvolution routine similar to several previous applications. The initial application of these techniques to three images covering the same region of the Martian surface but at different surface temperature and atmospheric conditions yields consistent surface spectral shapes as well as end-member concentrations. Retrieved aerosol opacity information is consistent with an independently developed opacity retrieval method. The application of the techniques described here is done in a stepwise fashion and may be applied to the desired level of analysis necessary for interpretation of surface properties.
C1 Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Bandfield, JL (reprint author), Arizona State Univ, Mars Space Flight Facil, Tempe, AZ 85287 USA.
EM joshband@asu.edu
RI Smith, Michael/C-8875-2012; Rogers, Deanne/I-9737-2016
OI Rogers, Deanne/0000-0002-4671-2551
NR 34
TC 59
Z9 59
U1 0
U2 5
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD OCT 21
PY 2004
VL 109
IS E10
AR E10008
DI 10.1029/2004JE002289
PG 17
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 867YC
UT WOS:000224877800001
ER
PT J
AU Forbes, KF
St Cyr, OC
AF Forbes, KF
St Cyr, OC
TI Space weather and the electricity market: An initial assessment
SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
LA English
DT Article
DE geomagnetically induced currents; electricity; coronal mass ejections;
space weather; economics; Dst
ID INDUCTION; SYSTEMS
AB The paper examines the economic impact of space weather by drawing on hourly data from the PJM power grid over the period 1 June 2000 through 31 December 2001. The PJM grid is one of the largest power pools in North America. As of 31 December 2001, its service area had a population of approximately 22 million and included all or part of Pennsylvania, New Jersey, Maryland, Delaware, Virginia, and the District of Columbia. Market prices are determined for every hour of the day. As of June 2000, there are actually two markets for energy: a real-time market in which market participants can buy and sell electricity in "real time'' and a day ahead market that allows participants to enter into transactions one day ahead of time. The existence of these two markets allows us to disentangle the effect of space weather conditions from other factors ( such as fuel prices and expected demand) that affect the baseline price ( as established in the day ahead market) for wholesale electricity. Several econometric analyses are conducted. The first examines the contribution of space weather to transmission congestion within the power grid. Building on the first analysis, the second analysis constructs an econometric model that examines the impact of space weather on the real-time market. Factors considered in the model include the outcome in the day ahead market, the level of generation utilization, unexpected demand, generation outages, unexpected transmission outages that are believed to be terrestrial in origin, and space weather. The results indicate the presence of space weather effects on the real-time price even after controlling for the other factors. A third model examines whether these space weather impacts affect subsequent prices in the far larger day ahead market.
C1 Catholic Univ Amer, Dept Econ & Business, Washington, DC 20064 USA.
NASA, Goddard Space Flight Ctr, Solar Phys Branch, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA.
RP Forbes, KF (reprint author), Catholic Univ Amer, Dept Econ & Business, 620 Michigan Ave NE, Washington, DC 20064 USA.
EM forbes@cua.edu
OI Forbes, Kevin/0000-0002-9521-6845
NR 21
TC 19
Z9 20
U1 1
U2 4
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 1542-7390
J9 SPACE WEATHER
JI Space Weather
PD OCT 21
PY 2004
VL 2
IS 10
AR S10003
DI 10.1029/2003SW000005
PG 28
WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
GA 909HW
UT WOS:000227852000002
ER
PT J
AU Beckmann, V
Gehrels, N
Favre, P
Walter, R
Courvoisier, TJL
Petrucci, PO
Malzac, J
AF Beckmann, V
Gehrels, N
Favre, P
Walter, R
Courvoisier, TJL
Petrucci, PO
Malzac, J
TI INTEGRAL and XMM-Newton spectral studies of NGC 4388
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE galaxies : active; galaxies : individual (NGC 4388); galaxies : Seyfert;
gamma rays : observations; X-rays : galaxies
ID ACTIVE GALACTIC NUCLEI; SEYFERT-2 GALAXY NGC-4388; X-RAY ASTRONOMY; ASCA
OBSERVATIONS; VIRGO CLUSTER; COMPTON-THIN; NGC 4388; BEPPOSAX;
REFLECTION; SPECTROMETER
AB We present INTEGRAL and XMM-Newton observations of a Seyfert galaxy, the type 2 active galactic nucleus (AGN) NGC 4388. Several INTEGRAL observations performed in 2003 allow us to study the spectrum in the 20-300 keV range. In addition, two XMM-Newton observations give detailed insight into the 0.2-10 keV emission. The measurements presented here and comparison with previous observations by BeppoSAX, SIGMA, and Compton Gamma Ray Observatory (CGRO) OSSE show that the overall spectrum from soft X-rays up to the gamma-rays can be described by a highly absorbed (N(H)similar or equal to2.7x10(23) cm(-2)) and variable nonthermal component in addition to constant nonabsorbed thermal emission (Tsimilar or equal to0.8 keV) of low abundance (Zapproximate to0.07 Z(circle dot)), plus constant Fe Kalpha and Kbeta lines. The hard X-ray component is well described by a simple power law with a mean photon index of Gamma=1.7. During the INTEGRAL observations, the 20-100 keV flux increased by a factor of 1.4. The analysis of XMM-Newton data implies that the emission below 3 keV is decoupled from the AGN and probably due to extended emission as seen in Chandra observations. The constant iron line emission is apparently also decoupled from the direct emission of the central engine and likely to be generated in the obscuring material, e.g., in the molecular torus.
C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
INTEGRAL Sci Data Ctr, CH-1290 Versoix, Switzerland.
Lab Astrophys Grenoble, F-38041 Grenoble, France.
Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France.
Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA.
Observ Geneva, CH-1290 Sauverny, Switzerland.
Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England.
RP Beckmann, V (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA.
EM beckmann@milkyway.gsfc.nasa.gov
RI Gehrels, Neil/D-2971-2012
NR 40
TC 31
Z9 31
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2004
VL 614
IS 2
BP 641
EP 647
DI 10.1086/423708
PN 1
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865KA
UT WOS:000224700200011
ER
PT J
AU Hyung, S
Feibelman, WA
AF Hyung, S
Feibelman, WA
TI Optical and IUE spectra of the planetary nebula NGC 7026
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE ISM : abundances; planetary nebulae : individual (NGC 7026); plasmas;
ultraviolet : ISM
ID AURORAL EMISSION-LINES; GASEOUS NEBULAE; IV; ATMOSPHERES; ABUNDANCES
AB We investigated spectroscopic data of the extended planetary nebula NGC 7026 in the wavelengths 3700-10,050 Angstrom, secured with the Hamilton Echelle Spectrograph at Lick Observatory. This optical wavelength spectrum has been analyzed along with the International Ultraviolet Explorer (IUE) UV spectral data. The diagnostic diagram indicates that the planetary nebula has very complex electron densities of N(epsilon)similar to3000-10,000 cm(-3). The electron temperatures are relatively low: around T-epsilon=8000-9500 K, probably as a result of an enhanced heavy elemental cooling. The electron temperature variation also indicates that the low-excitation line region is slightly higher than the high-excitation line regions perhaps as a result of the hardening of escaped UV ionizing photons into the outer shell part of low-excitation lines. We construct a photoionization model, with the central star of the planetary nebula at a temperature of T-eff=80,000 K, to fit most of the relatively strong line intensities and the observed physical conditions. With this photoionization model construction and with a semiempirical ionization correction method, we derived the elemental abundances of the nebula. Compared to the average or normal planetary nebula, most elemental abundances of He, C, N, O, Ne, S, Ar, and Cl appear to be enhanced.
C1 Chungbuk Natl Univ, Sch Sci Educ Astron, Cheongju 361763, Chungbuk, South Korea.
NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA.
RP Hyung, S (reprint author), Chungbuk Natl Univ, Sch Sci Educ Astron, 48 Gaeshin Dong, Cheongju 361763, Chungbuk, South Korea.
EM hyung@chungbuk.ac.kr; feibelman@iue.gsfc.nasa.gov
NR 33
TC 10
Z9 10
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2004
VL 614
IS 2
BP 745
EP 756
DI 10.1086/423660
PN 1
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865KA
UT WOS:000224700200021
ER
PT J
AU Hudgins, DM
Bauschlicher, CW
Sandford, SA
AF Hudgins, DM
Bauschlicher, CW
Sandford, SA
TI The impact of deuteration on the infrared spectra of interstellar
polycyclic aromatic hydrocarbons
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE astrochemistry; infrared : ISM; ISM : evolution; ISM : molecules;
molecular processes
ID 3 MICRON SPECTRA; H2O ICE BANDS; DEUTERIUM FRACTIONATION; EMISSION
FEATURES; ABUNDANCE RATIO; BENDING MODES; MU-M; MOLECULES; CLOUDS;
ABSORPTION
AB In this paper, we present the results of a computational study of the effects of a low absolute level of deuteration (similar to5%) on the observed mid-IR spectrum of the interstellar polycyclic aromatic hydrocarbon (PAH) population. The analyses are based on a global average spectrum, including all the possible singly deuterated isomers of an ensemble of partially superhydrogenated PAH species (i.e., H-n-PAHs) in both neutral and cationic forms. The distinctive spectroscopic properties considered in this paper include three classes of D-involved vibrational modes: (1) C-D in-plane bending features in the 9.5-12 mum region, (2) C-D out-of-plane bending features in the 14.5-17.9 mum region, and (3) aromatic and aliphatic C-D stretching features in the 4.4-4.7 mum region. In addition, D substitution also has the potential to alter the appearance of the C-H out-of-plane bending features in the 11-14 mum region by disrupting the adjacency of the H atoms on the PAH edge rings. The spectroscopic impacts of a low level of deuteration in the interstellar PAH population are considered, and their implications for the detailed appearance of the astronomical mid-IR PAH emission spectrum is explored. Overall, the results of this study indicate that the C-D stretching features offer the greatest prospects for the detection of deuterated interstellar PAHs. Since these features are effectively obscured by telluric CO2 absorptions, the information presented herein should be useful in the planning and design of future space-based IR observing platforms.
C1 NASA, Ames Res Ctr, Astrophys Branch, Moffett Field, CA 94035 USA.
NASA, Ames Res Ctr, Space Technol Div, Moffett Field, CA 94035 USA.
RP Hudgins, DM (reprint author), NASA, Ames Res Ctr, Astrophys Branch, MS 245-6, Moffett Field, CA 94035 USA.
EM dhudgins@mail.arc.nasa.gov
NR 72
TC 8
Z9 8
U1 0
U2 5
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2004
VL 614
IS 2
BP 770
EP 780
DI 10.1086/423930
PN 1
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865KA
UT WOS:000224700200023
ER
PT J
AU Abbas, MM
Craven, PD
Spann, JF
Tankosic, D
LeClair, A
Gallagher, DL
West, EA
Weingartner, JC
Witherow, WK
Tielens, AGGM
AF Abbas, MM
Craven, PD
Spann, JF
Tankosic, D
LeClair, A
Gallagher, DL
West, EA
Weingartner, JC
Witherow, WK
Tielens, AGGM
TI Laboratory experiments on rotation and alignment of the analogs of
interstellar dust grains by radiation
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE astrochemistry; dust, extinction; methods : laboratory
ID COSMIC DUST; PARTICLES; TORQUES; GAS; RELAXATION; PRESSURE; DYNAMICS;
SPHERE; MOTION; BODY
AB The processes and mechanisms involved in the rotation and alignment of interstellar dust grains have been of great interest in astrophysics ever since the surprising discovery of the polarization of starlight more than half a century ago. Numerous theories, detailed mathematical models, and numerical studies of grain rotation and alignment with respect to the Galactic magnetic field have been presented in the literature. In particular, the subject of grain rotation and alignment by radiative torques has been shown to be of particular interest in recent years. However, despite many investigations, a satisfactory theoretical understanding of the processes involved in grain rotation and alignment has not been achieved. As there appear to be no experimental data available on this subject, we have carried out some unique experiments to illuminate the processes involved in the rotation of dust grains in the interstellar medium. In this paper we present the results of some preliminary laboratory experiments on the rotation of individual micron/submicron-sized, nonspherical dust grains levitated in an electrodynamic balance evacuated to pressures of similar to10(-3) to 10(-5) torr. The particles are illuminated by laser light at 5320 Angstrom, and the grain rotation rates are obtained by analyzing the low-frequency (similar to0-100 kHz) signal of the scattered light detected by a photodiode detector. The rotation rates are compared with simple theoretical models to retrieve some basic rotational parameters. The results are examined in light of the current theories of alignment.
C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
Univ Alabama, Huntsville, AL 35899 USA.
George Mason Univ, Fairfax, VA 22030 USA.
Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands.
RP Abbas, MM (reprint author), NASA, George C Marshall Space Flight Ctr, 320 Sparkman Dr, Huntsville, AL 35812 USA.
EM mian.m.abbas@nasa.gov; paul.d.craven@nasa.gov; james.f.spann@nasa.gov;
dtankosic1@cs.com; andre.leclair@msfc.nasa.gov;
dennis.l.gallagher@nasa.gov; edward.a.west@nasa.gov;
joe@physics.gmu.edu; william.k.witherow@nasa.gov; tielens@astro.rug.nl
NR 53
TC 33
Z9 33
U1 1
U2 7
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2004
VL 614
IS 2
BP 781
EP 795
DI 10.1086/423023
PN 1
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865KA
UT WOS:000224700200024
ER
PT J
AU Dyks, J
Harding, AK
AF Dyks, J
Harding, AK
TI Rotational sweepback of magnetic field lines in geometric models of
pulsar radio emission
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE polarization; pulsars : general; radiation mechanisms : nonthermal
ID GAMMA-RAY PULSARS; EMPIRICAL-THEORY; POLARIZATION; MAGNETOSPHERES;
BEAMS; REFRACTION; HEIGHTS; REGION
AB We study the rotational distortions of the vacuum dipole magnetic field in the context of geometric models of the radio emission from pulsars. We find that at low altitudes the rotation deflects the local direction of the magnetic field by at most an angle of the order of r(n)(2),where r(n) r/R-1c, r is the radial distance, and R-1c is the light cylinder radius. To the lowest (i.e., second) order in r(n), this distortion is symmetric with respect to the plane containing the dipole axis and the rotation axis [(Omega, mu) plane]. The lowest order distortion that is asymmetric with respect to the (Omega, mu) plane is third-order in r(n). These results confirm the common assumption that the rotational sweepback has negligible effect on the position angle ( P. A.) curve. We show, however, that the influence of the sweepback on the outer boundary of the open field line region ( open volume) is a much larger effect, of the order of r(n)(1/2). The open volume is shifted backward with respect to the rotation direction by an angle delta(ov) similar to 0.2 sin alphar(n)(1/2), where alpha is the dipole inclination with respect to the rotation axis. The associated phase shift of the pulse profile Deltaphi(ov) similar to 0.2r(n)(1/2) can easily exceed the shift caused by combined effects of aberration and propagation time delays (approximate to2r(n)). This strongly affects the misalignment of the center of the P. A. curve and the center of the pulse profile, thereby modifying the delay-radius relation. Contrary to intuition, the effect of sweepback dominates over other effects when emission occurs at low altitudes. For r(n) less than or similar to3 x 10(-3) the shift becomes negative; i.e., the center of the P. A. curve precedes the profile center. With the sweepback effect included, the modified delay-radius relation predicts larger emission radii and is in much better agreement with the other methods of determining r(n).
C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
RP Dyks, J (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 660, Greenbelt, MD 20771 USA.
EM jinx@milkyway.gsfc.nasa.gov; harding@twinkie.gsfc.nasa.gov
RI Harding, Alice/D-3160-2012
NR 33
TC 48
Z9 48
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2004
VL 614
IS 2
BP 869
EP 880
DI 10.1086/423707
PN 1
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865KA
UT WOS:000224700200032
ER
PT J
AU Hickox, RC
Narayan, R
Kallman, TR
AF Hickox, RC
Narayan, R
Kallman, TR
TI Origin of the soft excess in X-ray pulsars
SO ASTROPHYSICAL JOURNAL
LA English
DT Review
DE accretion, accretion disks; pulsars : general; stars : neutron; X-rays :
binaries
ID SMALL-MAGELLANIC-CLOUD; PHASE RESOLVED-SPECTROSCOPY; NEUTRON STAR
MAGNETOSPHERE; 0.1-100 KEV SPECTRUM; BROAD-BAND SPECTRUM; ANOMALOUS LOW
STATE; BINARY 4U 1626-67; 35 DAY CYCLE; LMC X-4; VELA X-1
AB The spectra of many X-ray pulsars show, in addition to a power law, a low-energy component that has often been modeled as a blackbody with kT(BB) similar to 0.1 keV. However, the physical origin of this soft excess has remained a mystery. We examine a sample of well-studied bright X-ray pulsars, which have been observed using ROSAT, ASCA, Ginga, RXTE, BeppoSAX, Chandra, and XMM-Newton. In particular, we consider the Magellanic Cloud pulsars SMC X-1, LMC X-4, XTE J0111.2-7317, and RX J0059.2-7138 and the Galactic sources Her X-1, 4U 1626-67, Cen X-3, and Vela X-1. We show that the soft excess is a very common if not ubiquitous feature intrinsic to X-ray pulsars. We evaluate several possible mechanisms for the soft emission, using theoretical arguments, as well as observational clues, such as spectral shapes, eclipses, pulsations of the soft component, and superorbital modulation of the source flux. We find that reprocessing of hard X-rays from the neutron star by the inner region of the accretion disk is the only process that can explain the soft excess in all the pulsars with L-X greater than or similar to 10(38) ergs s(-1). Other mechanisms, such as emission from diffuse gas in the system, are important in less luminous objects.
C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
RP Hickox, RC (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA.
OI Narayan, Ramesh/0000-0002-1919-2730
NR 121
TC 86
Z9 86
U1 0
U2 3
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2004
VL 614
IS 2
BP 881
EP 896
DI 10.1086/423928
PN 1
PG 16
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865KA
UT WOS:000224700200033
ER
PT J
AU MacNeice, P
Antiochos, SK
Phillips, A
Spicer, DS
DeVore, CR
Olson, K
AF MacNeice, P
Antiochos, SK
Phillips, A
Spicer, DS
DeVore, CR
Olson, K
TI A numerical study of the breakout model for coronal mass ejection
initiation
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE Sun : corona; Sun : coronal mass ejections (CMEs); Sun : flares
ID FREE MAGNETIC-FIELDS; SOLAR ERUPTIONS; HELICITY BUDGET; FLUX-ROPES;
FLARES; RECONNECTION; ENERGY; CONFIGURATIONS; PROMINENCES; RELAXATION
AB A leading theory for the initiation of coronal mass ejections (CMEs) is the breakout model, in which magnetic reconnection above a filament channel is responsible for disrupting the coronal magnetic field. We present the first simulations of the complete breakout process including the initiation, the plasmoid formation and ejection, and the eventual relaxation of the coronal field to a more potential state. These simulations were performed using a new numerical code that solves the numerical cavitation problems that prevented previous simulations from calculating a complete ejection. Furthermore, the position of the outer boundary in the new simulations is increased out to 30 R(circle dot), which enables determination of the full structure and dynamics of the ejected plasmoid. Our results show that the ejection occurs at a speed on the order of the coronal Alfven speed and hence that the breakout model can produce fast CMEs. Another key result is that the ejection speed is not sensitive to the refinement level of the grid used in the calculations, which implies that, at least for the numerical resistivity of these simulations, the speed is not sensitive to the Lundquist number. We also calculate, in detail, the helicity of the system and show that the helicity is well conserved during the breakout process. Most of the helicity is ejected from the Sun with the escaping plasmoid, but a significant fraction (of order 10%) remains in the corona. The implications of these results for observation and prediction of CMEs and eruptive flares is discussed.
C1 Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA.
USN, Res Lab, Washington, DC 20375 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Maryland Baltimore Cty, Baltimore, MD 21250 USA.
RP MacNeice, P (reprint author), Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA.
EM macneice@alfven.gsfc.nasa.gov; antiochos@nrl.navy.mil;
phillips@sommerfeld.gsfc.nasa.gov; spicer@gauss.gsfc.nasa.gov;
devore@lcp.nrl.navy.mil; olson@bohr.gsfc.nasa.gov
RI MacNeice, Peter/F-5587-2012; Antiochos, Spiro/D-4668-2012; DeVore,
C/A-6067-2015
OI Antiochos, Spiro/0000-0003-0176-4312; DeVore, C/0000-0002-4668-591X
NR 51
TC 91
Z9 92
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2004
VL 614
IS 2
BP 1028
EP 1041
DI 10.1086/423887
PN 1
PG 14
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865KA
UT WOS:000224700200046
ER
PT J
AU Mizuno, T
Kamae, T
Godfrey, G
Handa, T
Thompson, DJ
Lauben, D
Fukazawa, Y
Ozaki, M
AF Mizuno, T
Kamae, T
Godfrey, G
Handa, T
Thompson, DJ
Lauben, D
Fukazawa, Y
Ozaki, M
TI Cosmic-ray background flux model based on a Gamma-Ray Large Area Space
Telescope balloon flight engineering model
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE balloons; cosmic rays; gamma rays : observations; instrumentation :
miscellaneous
ID NEAR-EARTH ORBIT; HELIUM SPECTRA; BESS SPECTROMETER; ELECTRONS; PROTON;
GLAST; ALBEDO; ATMOSPHERE; POSITRONS; RADIATION
AB Cosmic-ray background fluxes were modeled on the basis of existing measurements and theories and are presented here. The model, originally developed for the Gamma-Ray Large Area Space Telescope (GLAST) balloon experiment, covers the entire solid angle (4pi sr), the sensitive energy range of the instrument (similar to10 MeV to 100 GeV), and the abundant components (proton, alpha particle, e(-), e(+), mu(-), mu(+), and gamma ray). It is expressed in analytic functions in which modulations due to solar activity and the Earth's geomagnetism are parameterized. Although the model is intended to be used primarily for the GLAST balloon experiment, model functions in low Earth orbit are also presented and can be used for other high-energy astrophysical missions. The model has been validated via comparison with the data of the GLAST balloon experiment.
C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Stanford Univ, Hansen Expt Phys Lab, Stanford, CA 94305 USA.
Hiroshima Univ, Dept Phys, Hiroshima 7398526, Japan.
Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Kanagawa 2298510, Japan.
RP Mizuno, T (reprint author), Stanford Linear Accelerator Ctr, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA.
EM mizuno@slac.stanford.edu
RI Thompson, David/D-2939-2012; Ozaki, Masanobu/K-1165-2013
OI Thompson, David/0000-0001-5217-9135;
NR 40
TC 45
Z9 46
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2004
VL 614
IS 2
BP 1113
EP 1123
DI 10.1086/423801
PN 1
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865KA
UT WOS:000224700200052
ER
PT J
AU Bergin, E
Calvet, N
Sitko, ML
Abgrall, H
D'Alessio, P
Herczeg, GJ
Roueff, E
Qi, CH
Lynch, DK
Russell, RW
Brafford, SM
Perry, RB
AF Bergin, E
Calvet, N
Sitko, ML
Abgrall, H
D'Alessio, P
Herczeg, GJ
Roueff, E
Qi, CH
Lynch, DK
Russell, RW
Brafford, SM
Perry, RB
TI A new probe of the planet-forming region in T Tauri disks
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE accretion, accretion disks; astrobiology; astrochemistry; circumstellar
matter; stars : pre-main-sequence; ultraviolet : stars
ID MAIN-SEQUENCE EVOLUTION; MOLECULAR-HYDROGEN; ELECTRON-IMPACT;
CIRCUMSTELLAR DISKS; HYDRAE ASSOCIATION; H-2 FLUORESCENCE; ACCRETION
DISKS; YOUNG OBJECTS; GM-AURIGAE; EMISSION
AB We present new observations of the far-ultraviolet (FUV; 1100-2200 Angstrom) radiation field and the near- to mid-A IR (3-13.5 mum) spectral energy distribution (SED) of a sample of T Tauri stars selected on the basis of bright molecular disks (GM Aur, DM Tau, and LkCa 15). In each source we find evidence for Lyalpha-induced H(2) fluorescence and an additional source of FUV continuum emission below 1700 Angstrom. Comparison of the FUV spectra to a model of H(2) excitation suggests that the strong continuum emission is due to electron impact excitation of H(2). The ultimate source of this excitation is likely X-ray irradiation that creates hot photoelectrons mixed in the molecular layer. Analysis of the SED of each object finds the presence of inner disk gaps with sizes of a few AU in each of these young (similar to1 Myr) stellar systems. We propose that the presence of strong H(2) continuum emission and inner disk clearing are related by the increased penetration power of high-energy photons in gas-rich regions with low grain opacity.
C1 Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA.
Observ Paris, CNRS, Lab Universe & Theories, UMR 8102,Sect Meudon, F-92195 Meudon, France.
Univ Nacl Autonoma Mexico, Inst Astron, Morelia 58089, Michoacan, Mexico.
Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA.
Aerosp Corp, Los Angeles, CA 90009 USA.
Univ Dayton, Sch Law, Dayton, OH 45469 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Bergin, E (reprint author), Univ Michigan, Dept Astron, 825 Denninson Bldg,501 E Univ Ave, Ann Arbor, MI 48109 USA.
EM ebergin@umich.edu
OI Herczeg, Gregory/0000-0002-7154-6065
NR 30
TC 73
Z9 74
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2004
VL 614
IS 2
BP L133
EP L136
DI 10.1086/425865
PN 2
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865KB
UT WOS:000224700300011
ER
PT J
AU Fiorito, R
Titarchuk, L
AF Fiorito, R
Titarchuk, L
TI Is M82 X-1 really an intermediate-mass black hole? X-ray spectral and
timing evidence
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE accretion, accretion disks; black hole physics; radiation mechanisms :
nonthermal
ID QUASI-PERIODIC OSCILLATIONS; NOVA XTE J1550-564; GRO J1655-40;
FREQUENCY; ACCRETION; GALAXIES; BINARIES
AB Ultraluminous X-ray sources (ULXs) with apparent luminosities up to hundreds of times the Eddington luminosity for a neutron star have been discovered in external galaxies. The existence of intermediate-mass black holes has been proposed to explain these sources. We present evidence for an intermediate-mass black hole in the ULX M82 X-1 based on the spectral features and timing (quasi-periodic oscillation [QPO]) properties of the X-radiation from this source. We revisited XMM-Newton and Rossi X-Ray Timing Explorer (RXTE) data for M82 X-1 obtained in 2001 and 1997 for XMM and RXTE, respectively. We show for these observations that the source is either in transition or in a high/soft state with photon spectral indices 2.1 and 2.7, respectively. We confirm the early determination of the QPO frequency v approximate to 55 mHz in this source by Strohmayer & Mushotzky and identify this as the low- frequency QPO for the source. We apply a new method to determine the black hole mass of M82 X-1. The method uses the index-QPO low-frequency correlation that has been recently established in Galactic black hole candidates GRS 1915 + 105, XTE J1550-564, 4U 1630-47, and others. Using scaling arguments and the correlation derived from the consideration of Galactic black holes, we conclude that M82 X-1 is an intermediate black hole with a mass of the order of 1000 M-circle dot.
C1 Univ Maryland, College Pk, MD 20742 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
George Mason Univ, CEOSR, Fairfax, VA 22030 USA.
USN, Res Lab, Washington, DC 20375 USA.
RP Fiorito, R (reprint author), Univ Maryland, College Pk, MD 20742 USA.
EM rfiorito@milkyway.gsfc.nasa.gov; ltitarchuk@ssd5.nrl.navy.mil
NR 17
TC 36
Z9 36
U1 1
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2004
VL 614
IS 2
BP L113
EP L116
DI 10.1086/425736
PN 2
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865KB
UT WOS:000224700300006
ER
PT J
AU Villarreal, AR
Strohmayer, TE
AF Villarreal, AR
Strohmayer, TE
TI Discovery of the neutron star spin frequency in EXO 0748-676
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE binaries : general; stars : individual (EXO 0748-676); stars : neutron;
stars : rotation; X-rays : bursts; X-rays : stars
ID X-RAY BINARY; QUASI-PERIODIC OSCILLATION; EXO 0748-676; BURSTS;
DEPENDENCE; EMISSION; EQUATION; LINES
AB We report the results of a search for burst oscillations during thermonuclear X-ray bursts from the low-mass X-ray binary EXO 0748-676. With the proportional counter array on board the Rossi X-Ray Timing Explorer (RXTE), we detected a 45 Hz oscillation in the average power spectrum of 38 thermonuclear X-ray bursts from this source. We computed power spectra with 1 Hz frequency resolution for both the rising and decaying portions of 38 X-ray bursts from the public RXTE archive. We averaged the 1 Hz power spectra and detected a significant signal at 45 Hz in the decaying phases of the bursts. The signal is detected at a significance level of 4 x 10(-8). No similar signal was detected in the rising intervals. A fit to the oscillation peak at 0.25 Hz resolution gives a frequency of v(0) = 44.7 +/- 0.06 Hz and an oscillation quality factor of Q = v(0)/Deltav(FWHM). The average signal amplitude is approximate to3% (rms). The detection of 45 Hz burst oscillations from EXO 0748-676 provides compelling evidence that this is the neutron star spin frequency in this system. We use the inferred spin frequency to model the widths of absorption lines from the neutron star surface and show that the widths of the absorption lines from EXO 0748-676 recently reported by Cottam et al. are consistent with a 45 Hz spin frequency as long as the neutron star radius is in the range from about 9.5 to 15 km. With a known spin frequency, precise modeling of the line profiles from EXO 0748-676 holds great promise for constraining the dense matter equation of state.
C1 Univ Arizona, Dept Phys, Tucson, AZ 85721 USA.
NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
RP Villarreal, AR (reprint author), Univ Arizona, Dept Phys, 1118 E 4th St, Tucson, AZ 85721 USA.
EM adamv@physics.arizona.edu; stroh@milkyway.gsfc.nasa.gov
NR 22
TC 66
Z9 67
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 20
PY 2004
VL 614
IS 2
BP L121
EP L124
DI 10.1086/425737
PN 2
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865KB
UT WOS:000224700300008
ER
PT J
AU Benson, RF
Webb, PA
Green, JL
Garcia, L
Reinisch, BW
AF Benson, RF
Webb, PA
Green, JL
Garcia, L
Reinisch, BW
TI Magnetospheric electron densities inferred from upper-hybrid band
emissions
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID RADIO; IMAGE; NOISE
AB The magnetospheric electron density N-e can often be obtained to within a few percent from passive radio-wave dynamic spectra when the electron plasma frequency f(pe) (proportional to N-e(1/2)) is greater than the electron cyclotron frequency f(ce). This conclusion is based on interleaved active and passive observations from the Radio Plasma Imager (RPI) on the IMAGE satellite in the vicinity of the plasmapause. The N-e determinations are based on the frequency limits of an intense narrowband emission identified as the upper-hybrid band. The lower limit is identified with fpe and the upper limit with the upper-hybrid frequency f(uh) = (f(pe)(2) + f(ce)(2))(1/2). These frequency limits and the large amplitude of the emission, typically 20 dB or more above background, suggest strong Z-mode waves, rather than quasi-thermal fluctuations, as the emission source.
C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Nomad Res, Arnold, MD USA.
QSS Grp Inc, Greenbelt, MD USA.
Univ Massachusetts, Dept Environm Earth & Atmospher Sci, Ctr Atmospher Res, Lowell, MA 01854 USA.
RP Benson, RF (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
EM robert.f.benson@nasa.gov
NR 11
TC 30
Z9 30
U1 0
U2 0
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 20
PY 2004
VL 31
IS 20
AR L20803
DI 10.1029/2004GL020847
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 867XI
UT WOS:000224875700003
ER
PT J
AU Zak, M
AF Zak, M
TI Dynamical networks for information processing
SO INFORMATION SCIENCES
LA English
DT Article
AB Coupled evolution of state and topology of dynamical networks is introduced. Due to a well organized tensor structure, the governing equations are presented in a canonical form, and required attractors as well as their basins can be easily placed and controlled. This new class of dynamical networks can represent phenomenological models for self-organization in physics and biology. Applications of these networks to pattern recognition, associative memory, synthesis of models based upon observation data, detection of abnormalities and data compression are discussed. The difference between the proposed dynamical networks and neural networks is emphasized. (C) 2003 Elsevier Inc. All rights reserved.
C1 CALTECH, Jet Prop Lab, Ultracomp Grp, Pasadena, CA 91109 USA.
Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN USA.
RP Zak, M (reprint author), CALTECH, Jet Prop Lab, Ultracomp Grp, 4800 Oak Grove Dr,M-S 126-347, Pasadena, CA 91109 USA.
EM michail.zak@jpl.nasa.gov
NR 6
TC 3
Z9 3
U1 0
U2 0
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0020-0255
J9 INFORM SCIENCES
JI Inf. Sci.
PD OCT 19
PY 2004
VL 165
IS 3-4
BP 149
EP 169
DI 10.1016/j.ins.2003.08.019
PG 21
WC Computer Science, Information Systems
SC Computer Science
GA 864MM
UT WOS:000224637600001
ER
PT J
AU Curtis, S
Adler, RF
Huffman, GJ
Gu, GJ
AF Curtis, S
Adler, RF
Huffman, GJ
Gu, GJ
TI Westerly wind events and precipitation in the eastern Indian Ocean as
predictors for El Nino: Climatology and case study for the 2002-2003 El
Nino
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE precipitation; El Nino; onset
ID SEA-SURFACE TEMPERATURE; MADDEN-JULIAN OSCILLATION; EQUATORIAL PACIFIC;
INTRASEASONAL VARIABILITY; GLOBAL PRECIPITATION; TROPICAL PACIFIC;
ANOMALIES; MODULATION; ATMOSPHERE; CONVECTION
AB [1] This study expands on recent work linking intraseasonal-to-seasonal variability in observed precipitation and wind from September to March in the eastern Indian Ocean with the initiation of El Nino events during the last 25 years. First, westerly wind burst (WWB) events are defined as days when westerly wind speeds averaged over 5degrees - 15degreesS and 70degrees - 100 degreesE were greater than 1.5 standard deviations from the mean. The number of WWB days from September to March was high before the onset of the 1982 - 1983, 1991 - 1992, 1997 - 1998, and 2002 - 2003 El Nino events, but not the 1986 - 1987 El Nino. This study suggests that for the 1979 - 2002 period, variations in precipitation in the eastern Indian Ocean is a more robust predictor of El Nino onset than analyzed winds. On the basis of the work of Curtis et al. [2002], a real-time precipitation-based El Nino Onset Index is presented, which during the austral summer of 2001 - 2002 successfully predicted the 2002 - 2003 El Nino. The index focuses on the magnitude of 30 - 60 day oscillations and mean conditions in the precipitation field. Case studies of high-resolution satellite-based data sets of precipitation, wind, and sea surface temperature (SST) for the 2001 - 2002 season are examined to better understand how events in the Indian Ocean are linked to Pacific Ocean wind disturbances and SST changes. Twice during this season maxima in precipitation and zonal winds propagated eastward, the first near the equator and the second to the south. For the southern case, warm waters preceded heavy precipitation in the eastern Indian Ocean, which preceded strong westerly winds. A cooling of the sea surface followed the wind-rain system. This sequence of events moved through the ocean passage between Indonesia and Australia, suggesting a coupling of convection, wind, and sea surface temperatures on the timescale of days. These case studies provide a basis for how the east Indian Ocean variations are linked to subsequent events in the Pacific Ocean, including the initiation of El Nino events.
C1 E Carolina Univ, Dept Geog, Greenville, NC 27858 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
RP Curtis, S (reprint author), E Carolina Univ, Dept Geog, A232, Greenville, NC 27858 USA.
EM curtisw@mail.ecu.edu; adler@agnes.gsfc.nasa.gov;
huffman@agnes.gsfc.nasa.gov; gu@agnes.gsfc.nasa.gov
RI Curtis, Scott/C-1115-2013; Huffman, George/F-4494-2014;
OI Huffman, George/0000-0003-3858-8308; Curtis, Scott/0000-0001-9065-8639
NR 34
TC 7
Z9 7
U1 0
U2 9
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 19
PY 2004
VL 109
IS D20
AR D20104
DI 10.1029/2004JD004663
PG 11
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 867XQ
UT WOS:000224876600007
ER
PT J
AU Diab, RD
Thompson, AM
Mari, K
Ramsay, L
Coetzee, GJR
AF Diab, RD
Thompson, AM
Mari, K
Ramsay, L
Coetzee, GJR
TI Tropospheric ozone climatology over Irene, South Africa, from 1990 to
1994 and 1998 to 2002
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE tropospheric ozone; Africa; tropical climatology
ID BIOMASS-BURNING EMISSIONS; GROUND-BASED OBSERVATIONS;
VERTICAL-DISTRIBUTION; ATMOSPHERIC TRANSPORT; TROPICAL TROPOSPHERE;
TRACE-A; OZONESONDES; PHOTOCHEMISTRY; BRAZZAVILLE; SAFARI-92
AB [1] Ozonesonde measurements over Irene in South Africa are reported for the period 1990 to 1994 and a more recent period, 1998 to 2002, when the station became part of the Southern Hemisphere Additional Ozonesondes (SHADOZ) network. Irene displays the characteristic Southern Hemisphere springtime tropospheric ozone maximum, but its seasonal features are modulated by both tropical and midlatitude influences because of its location (25degrees540S, 28degrees13'E) on the boundary of zonally defined meteorological regimes. The tropical savanna biomass burning signature, namely, the spring maximum, is less distinct in the lower troposphere than at stations closer to biomass burning source regions nearer the equator, although long-range transport and recirculation in the subtropical anticyclonic gyre over southern Africa permit the buildup of relatively high springtime midtropospheric ozone. Midlatitude dynamical influences are evident, predominantly in winter when upper tropospheric ozone is enhanced as a result of stratospheric-tropospheric injection of ozone. Mean tropospheric ozone values range between 40 and 60 ppbv throughout the year and increase by similar to20 ppbv in spring. The increase (similar to10 ppbv) in surface and lower tropospheric ozone between the two time periods is attributed to an increase in urban-industrial emissions. A classification of ozone profiles using a cluster analysis has enabled the delineation of a background and "most polluted'' profile. Enhancements of at least 30% occur throughout the troposphere in spring, and in certain layers, increases close to 100% are observed.
C1 Univ KwaZulu Natal, Sch Environm Sci, ZA-4041 Durban, South Africa.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
S African Weather Serv, ZA-0001 Pretoria, South Africa.
RP Univ KwaZulu Natal, Sch Environm Sci, King George V Ave, ZA-4041 Durban, South Africa.
EM diab@ukzn.ac.za
RI Thompson, Anne /C-3649-2014;
OI Thompson, Anne /0000-0002-7829-0920; Diab, Roseanne/0000-0002-3564-8320
NR 49
TC 22
Z9 22
U1 0
U2 9
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 19
PY 2004
VL 109
IS D20
AR D20301
DI 10.1029/2004JD004793
PG 11
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 867XQ
UT WOS:000224876600014
ER
PT J
AU Eldering, A
Kahn, BH
Mills, FP
Irion, FW
Steele, HM
Gunson, MR
AF Eldering, A
Kahn, BH
Mills, FP
Irion, FW
Steele, HM
Gunson, MR
TI Vertical profiles of aerosol volume from high spectral resolution
infrared transmission measurements: Results
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE stratospheric aerosol; Mt. Pinatubo
ID STRATOSPHERIC AEROSOL; OPTICAL-CONSTANTS; PINATUBO AEROSOL;
FOURIER-TRANSFORM; SHUTTLE MISSIONS; SULFATE AEROSOLS; MOUNT-PINATUBO;
SURFACE-AREA; EVOLUTION; H2SO4
AB [1] The high-resolution infrared absorption spectra of the Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment are utilized to derive vertical profiles of sulfate aerosol volume density and extinction coefficient. Following the eruption of Mt. Pinatubo in June 1991, the ATMOS spectra obtained on three Space Shuttle missions ( 1992, 1993, and 1994) provide a unique opportunity to study the global stratospheric sulfate aerosol layer shortly after a major volcanic eruption and periodically during the decay phase. Synthetic sulfate aerosol spectra are fit to the observed spectra, and a global fitting inversion routine is used to derive vertical profiles of sulfate aerosol volume density. Vertical profiles of sulfate aerosol volume density for the three missions over portions of the globe are presented, with the peak in aerosol volume density occurring from as low as 10 km ( polar latitudes) to as high as 20 km ( subtropical latitudes). Derived aerosol volume density is as high as 2 - 3.5 mum(3) cm(-3) +/- 10% in 1992, decreasing to 0.2 - 0.5 mum(3) cm(-3) +/- 20% in 1994, in agreement with other experiments. Vertical extinction profiles derived from ATMOS are compared with profiles from Improved Stratospheric And Mesospheric Sounder (ISAMS) and Cryogenic Limb Array Etalon Spectrometer (CLAES) that coincide in space and time and show good general agreement. The uncertainty of the ATMOS vertical profiles is similar to CLAES and consistently smaller than ISAMS at similar altitudes.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA USA.
Calif State Univ Northridge, Dept Geog, Northridge, CA 91330 USA.
RP Eldering, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 183-601, Pasadena, CA 91109 USA.
EM annmarie.eldering@jpl.nasa.gov
NR 37
TC 5
Z9 6
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 19
PY 2004
VL 109
IS D20
AR D20201
DI 10.1029/2004JD004623
PG 11
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 867XQ
UT WOS:000224876600006
ER
PT J
AU Takegawa, N
Kondo, Y
Koike, M
Chen, G
Machida, T
Watai, T
Blake, DR
Streets, DG
Woo, JH
Carmichael, GR
Kita, K
Miyazaki, Y
Shirai, T
Liley, JB
Ogawa, T
AF Takegawa, N
Kondo, Y
Koike, M
Chen, G
Machida, T
Watai, T
Blake, DR
Streets, DG
Woo, JH
Carmichael, GR
Kita, K
Miyazaki, Y
Shirai, T
Liley, JB
Ogawa, T
TI Removal of NOx and NOy in Asian outflow plumes: Aircraft measurements
over the western Pacific in January 2002
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE reactive nitrogen; removal process; Asian outflow
ID EXPLORATORY MISSION-WEST; REACTIVE NITROGEN; BOUNDARY-LAYER; PEM-WEST;
CHEMICAL EVOLUTION; NORTHERN AUSTRALIA; CARBON-MONOXIDE; EMISSIONS;
BIOMASS; INSTRUMENT
AB [1] The Pacific Exploration of Asian Continental Emission Phase A (PEACE-A) aircraft measurement campaign was conducted over the western Pacific in January 2002. Correlations of carbon monoxide ( CO) with carbon dioxide (CO2) and back trajectories are used to identify plumes strongly affected by Asian continental emissions. DeltaCO/DeltaCO(2) ratios (i.e., linear regression slopes of CO/CO2) in the plumes generally fall within the variability range of the CO/CO2 emission ratios estimated from an emission inventory for east Asia, demonstrating the consistency between the aircraft measurements and the emission characterization. Removal rates of reactive nitrogen (NOx and NOy) for the study region ( altitude < 4 km, 124 degrees - 140 degrees E, 25 degrees - 45 degrees N) are estimated using the correlation with CO2, the photochemical age of the plumes, and the NOx/CO2 emission ratio derived from the emission inventory. The plume age is estimated from the rates of hydrocarbon decay and hydroxyl radical (OH) concentration calculated using a constrained photochemical box model. The average lifetime of NOx is estimated to be 1.2 +/- 0.4 days. Possible processes controlling the NOx lifetime are discussed in conjunction with results from earlier studies. The average lifetime of NOy is estimated to be 1.7 +/- 0.5 days, which is comparable to the NOy lifetime of 1.7 - 1.8 days that has been previously reported for outflow from the United States. This similarity suggests the importance of chemical processing near the source regions in determining the NOy abundance.
C1 Univ Tokyo, Adv Sci & Technol Res Ctr, Tokyo 1538904, Japan.
Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
Natl Inst Environm Studies, Tsukuba, Ibaraki 3050053, Japan.
Global Environm Forum, Tsukuba, Ibaraki 3050053, Japan.
Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA.
Argonne Natl Lab, Decis & Informat Sci Div, Argonne, IL 60439 USA.
Univ Iowa, Ctr Global & Reg Environm Res, Iowa City, IA 52242 USA.
Ibaraki Univ, Fac Sci, Dept Environm Sci, Ibaraki 3108512, Japan.
Japan Aerosp Explorat Agcy, Earth Observat Res & Applicat Ctr, Tokyo 1046023, Japan.
Natl Inst Water & Atmospher Res, Lauder, New Zealand.
RP Univ Tokyo, Adv Sci & Technol Res Ctr, 4-6-1 Komaba, Tokyo 1538904, Japan.
EM takegawa@atmos.rcast.u-tokyo.ac.jp; kondo@atmos.rcast.u-tokyo.ac.jp;
koike@eps.s.u-tokyo.ac.jp; g.chen@larc.nasa.gov; tmachida@nies.go.jp;
watai.tomonori@nies.go.jp; dblake@uci.edu; dstreets@anl.gov;
woojh21@cgrer.uiowa.edu; gcarmich@engineering.uiowa.edu;
kita@env.sci.ibaraki.ac.jp; yuzom@atmos.rcast.u-tokyo.ac.jp;
shirai@eorc.jaxa.jp; b.liley@niwa.co.nz; ogawa.toshihiro@jaxa.jp
RI Koike, Makoto/F-4366-2011; Kondo, Yutaka/D-1459-2012; Miyazaki,
Yuzo/C-6920-2010
NR 39
TC 29
Z9 29
U1 0
U2 5
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 19
PY 2004
VL 109
IS D23
AR D23S04
DI 10.1029/2004JD004866
PG 16
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 867XW
UT WOS:000224877200001
ER
PT J
AU Kletetschka, G
Acuna, MH
Kohout, T
Wasilewski, PJ
Connerney, JEP
AF Kletetschka, G
Acuna, MH
Kohout, T
Wasilewski, PJ
Connerney, JEP
TI An empirical scaling law for acquisition of thermoremanent magnetization
SO EARTH AND PLANETARY SCIENCE LETTERS
LA English
DT Article
DE thermoremanent magnetism; efficiency of remanent magnetism; saturation
magnetism; paleointensity; magnetic mineralogy; Neel theory; grain size
ID REMANENT MAGNETIZATION; GRAIN-SIZE; MAGNETOCRYSTALLINE ANISOTROPY;
FIELD-DEPENDENCE; HIGH-TEMPERATURE; ROCK-MAGNETISM; IGNEOUS ROCKS;
HEMATITE; ANOMALIES; XFE2TIO4.(1-X)FE3O4
AB We describe a universal linear relationship between the acquisition magnetic field, B, and thermoremanent magnetization M-tr(T-r) measured at room temperature T-r. The efficiency epsilon(T-r) of a remanent magnetization (REM) is the ratio of the natural remanent magnetization M-nr(T-r) to the saturation remanence J(sr)(T-r). We report a power law relationship with exponent related to J(s)(T-r) and unit slope indicating a linear relationship. Thus logepsilon(T-r) of M-tr(T-r) in equidimensional-shaped magnetic minerals of contrasting saturation magnetization J(s)(T-r) plots linearly with the logarithm of the applied magnetic field B along separate grain-size-independent straight lines with nearly unit slope and offsets related to J(s)(T-r), This empirical relationship is well suited for paleofield-intensity estimation, predicts strong magnetization of hematite and pyrrhotite in weak fields, and can be used as an assessment tool for observed remanence in planetary and meteoritic objects. (C) 2004 Elsevier B.V. All rights reserved.
C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA.
Acad Sci Czech Republ, Inst Geol, Prague, Czech Republic.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Charles Univ, Fac Nat Sci, Dept Appl Geophy, Prague, Czech Republic.
RP Kletetschka, G (reprint author), Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA.
EM gunther.kletetschka@gsfc.nasa.gov
RI Kletetschka, Gunther/C-9996-2011; Kohout, Tomas/C-1394-2008; connerney,
john/I-5127-2013;
OI Kletetschka, Gunther/0000-0002-0645-9037; Kohout,
Tomas/0000-0003-4458-3650; connerney, jack/0000-0001-7478-6462
NR 34
TC 31
Z9 32
U1 1
U2 10
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0012-821X
J9 EARTH PLANET SC LETT
JI Earth Planet. Sci. Lett.
PD OCT 15
PY 2004
VL 226
IS 3-4
BP 521
EP 528
DI 10.1016/j.epsl.2004.08.001
PG 8
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 864QX
UT WOS:000224649100017
ER
PT J
AU Chen, SH
Tao, G
Joshi, SM
AF Chen, SH
Tao, G
Joshi, SM
TI Adaptive actuator failure compensation control for MIMO systems
SO INTERNATIONAL JOURNAL OF CONTROL
LA English
DT Article
ID FAULT-DIAGNOSIS; FEEDBACK; SCHEME
AB Two adaptive failure compensation control schemes based on MRAC are developed for a class of MIMO LTI systems with unknown actuator failures. An effective controller structure is proposed to achieve the desired plant-model output matching when implemented with matching parameters. Design conditions are specified for such nominal plant-model output matching. Two adaptive versions of the nominal controller are proposed and stable adaptive laws are derived for updating the controller parameters when plant parameters and failure parameters are unknown. All closed-loop signals are bounded and the plant outputs track the given reference outputs asymptotically, despite the uncertainties in actuator failures and plant parameters. Simulation results for an aircraft lateral dynamic model verify the desired adaptive control system performance in the presence of unknown rudder and aileron failures.
C1 Univ Michigan, Dept Naval Architecture & Marine Engn, Ann Arbor, MI 48109 USA.
NASA, Langley Res Ctr, Hampton, VA USA.
RP Tao, G (reprint author), Univ Michigan, Dept Naval Architecture & Marine Engn, Ann Arbor, MI 48109 USA.
EM gt9s@ee.Virginia.edu
NR 15
TC 9
Z9 10
U1 0
U2 3
PU TAYLOR & FRANCIS LTD
PI ABINGDON
PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND
SN 0020-7179
J9 INT J CONTROL
JI Int. J. Control
PD OCT 15
PY 2004
VL 77
IS 15
BP 1307
EP 1317
DI 10.1080/0020717042000297180
PG 11
WC Automation & Control Systems
SC Automation & Control Systems
GA 875FJ
UT WOS:000225405400002
ER
PT J
AU Choi, SR
Pereira, JM
Janosik, LA
Bhatt, RT
AF Choi, SR
Pereira, JM
Janosik, LA
Bhatt, RT
TI Foreign object damage in disks of gas-turbine-grade silicon nitrides by
steel ball projectiles at ambient temperature
SO JOURNAL OF MATERIALS SCIENCE
LA English
DT Article
ID IMPACT DAMAGE; STRENGTH DEGRADATION; STRUCTURAL CERAMICS; TENSILE CREEP;
PARTICLES; BEHAVIOR; SURFACES; SPHERES; MODEL
AB Foreign object damage (FOD) behavior of two commercial gas-turbine-grade silicon nitrides, AS800 and SN282, was determined at ambient temperature through postimpact strength testing of target disks impacted by steel ball projectiles with a diameter of 1.59 mm in a velocity range from 115 to 440 m/s. AS800 silicon nitride exhibited a greater FOD resistance than SN282, primarily due to its greater value of fracture toughness (K-lc). The critical impact velocity V-c for which the corresponding postimpact strength was the lowest was V(c)approximate to440 and 300 m/s for AS800 and SN282, respectively. A unique lower strength regime was typified for both silicon nitrides depending on impact velocity and was attributed to significant radial cracking. The damage generated by projectile impact was typically in the form of ring, radial, and cone cracks with their severity and combination being dependent on impact velocity. Unlike the thick (3 mm) flexure bar target specimens used in previous studies, the thin (2 mm) disk target specimens exhibited a unique back-side radial cracking on the reverse side just beneath the impact sites at and above impact velocities of 160 m/s for SN282 and 220 m/s for AS800. (C) 2004 Kluwer Academic Publishers.
C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Choi, SR (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
EM sung.r.choi@grc.nasa.gov
NR 26
TC 24
Z9 24
U1 1
U2 6
PU KLUWER ACADEMIC PUBL
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0022-2461
J9 J MATER SCI
JI J. Mater. Sci.
PD OCT 15
PY 2004
VL 39
IS 20
BP 6173
EP 6182
DI 10.1023/B:JMSC.0000043584.35335.58
PG 10
WC Materials Science, Multidisciplinary
SC Materials Science
GA 871BK
UT WOS:000225104100002
ER
PT J
AU Bloemhof, EE
AF Bloemhof, EE
TI Static point-spread function correction dominating higher-order speckle
terms at high adaptive correction
SO OPTICS LETTERS
LA English
DT Article
ID REMNANT SPECKLES; OPTICS; CORONAGRAPH; PERFORMANCE; NOISE
AB At high adaptive correction, the randomly shifting speckles familiar in conventional astronomical imaging become organized into patterns with distinct regularities that may permit partial suppression of the image noise they produce. Mathematically, the phase exponential in the Fourier-optical imaging expression may be expanded in a Taylor series in remnant phase phi, which is small at very high correction, leading to a perturbed point-spread function (PSF) that is a sum of algebraic terms, each of distinct spatial symmetry. At sufficiently high correction, one need deal with only a few of the lowest-order terms. A first-order expansion gives an ideal PSF plus two terms, linear and quadratic, describing the two brightest, physically most relevant kinds of speckle. A second-order expansion gives three new terms, the brightest of which is primarily a static correction to the PSF, with a much smaller true speckle component. When the correction is great enough to isolate individual speckle terms, the two terms from the first-order expansion alone determine the essential physics. A general observational strategy is outlined for reducing speckle noise in highly corrected companion searches, dominated by a few speckle terms of definite spatial symmetry. (C) 2004 Optical Society of America.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Bloemhof, EE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Eric.E.Bloemhof@jpl.nasa.gov
NR 17
TC 4
Z9 4
U1 0
U2 0
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 0146-9592
J9 OPT LETT
JI Opt. Lett.
PD OCT 15
PY 2004
VL 29
IS 20
BP 2333
EP 2335
DI 10.1364/OL.29.002333
PG 3
WC Optics
SC Optics
GA 860PO
UT WOS:000224355700001
PM 15532258
ER
PT J
AU Kondo, Y
Nakamura, K
Chen, G
Takegawa, N
Koike, M
Miyazaki, Y
Kita, K
Crawford, J
Ko, M
Blake, DR
Kawakami, S
Shirai, T
Liley, B
Wang, Y
Ogawa, T
AF Kondo, Y
Nakamura, K
Chen, G
Takegawa, N
Koike, M
Miyazaki, Y
Kita, K
Crawford, J
Ko, M
Blake, DR
Kawakami, S
Shirai, T
Liley, B
Wang, Y
Ogawa, T
TI Photochemistry of ozone over the western Pacific from winter to spring
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE ozone; troposphere; western Pacific
ID TROPOSPHERIC OZONE; REACTIVE NITROGEN; NORTH PACIFIC; LOWERMOST
STRATOSPHERE; CHEMICAL EVOLUTION; PEM-WEST; TRANSPORT; CHEMISTRY; TOPSE;
BUDGETS
AB Aircraft measurements of ozone (O-3) and its precursors, including NO, CO, H2O, and nonmethane hydrocarbons (NMHCs), were made over the western Pacific in the 20degrees-45degreesN latitude range in January and April-May 2002 during the Pacific Exploration of Asian Continental Emission (PEACE)-A and B campaigns. These measurements have provided data sets that, in combination with Transport and Chemical Evolution over the Pacific (TRACE-P) data taken in March 2001, enable studies of O-3 photochemistry from winter to late spring. A photochemical box model is used to calculate ozone formation (F(O-3)) and destruction (D(O-3)) rates constrained by the observed species concentrations. The values of F(O-3) and D(O-3) are controlled directly by NO, J((OD)-D-1) (O-3 photolysis frequency), H2O, OH, and HO2. Changes in HO2 concentration cause corresponding changes in both F(O-3) and D(O-3), leading to their coupling. Concentrations of these species, which are strongly influenced by photochemistry and transport from the Asian continent, underwent large seasonal variations. In the boundary layer (0-3 km), NO was much higher in January than in April-May, because of stronger winds, lower convective activities, and lower oxidation rates by OH in winter. The net O-3 formation rate, given by P(O-3) = F(O-3)-D(O-3), was largely positive in the boundary layer at 30degrees-45degreesN (1.5-4 ppbv d(-1)) in January, mainly because of high NO and low H2O values. Net O-3 formation continued from January to the end of March, demonstrating that the western Pacific is an important O-3 source region during this season. Net O-3 formation nearly ceased by late April/May because of the decrease in NO and the increase in H2O. In the latitude range of 20degrees-30degreesN, P(O-3) in the boundary layer was positive in January and turned negative by March. The earlier transition was mainly due to lower NO and higher H2O concentrations, combined with weaker transport and higher temperatures than those at 30degrees-45degreesN. The upper troposphere (6-12 km) has been shown to be a region of net O-3 formation throughout most of the year because of high NO and low H2O. The present study illustrates that a decrease in the net O-3 formation rate at 20degrees-45degreesN latitude from winter to late spring is explained systematically by the increases in J((OD)-D-1), H2O, OH, and HO2 (primarily due to increases in temperature and solar radiation) and the decrease in NO ( primarily due to decrease in transport from the Asian continent). Differences in the seasonal variation of O-3 photochemistry observed over the North American continent are interpreted in terms of the differences in factors controlling O-3 formation and destruction.
C1 Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, Tokyo 1538904, Japan.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
Univ Tokyo, Dept Earth & Planetary Sci, Grad Sch Sci, Bunkyo Ku, Tokyo 1130033, Japan.
Ibaraki Univ, Grad Sch Sci, Dept Environm Sci, Mito, Ibaraki 3108512, Japan.
Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA.
Japan Aerosp Explorat Agcy, Earth Observat Res & Applicat Ctr, Chuo Ku, Tokyo 1046023, Japan.
Natl Inst Water & Atmospher Res, Lauder 9182, New Zealand.
Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA.
RP Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, 4-6-1 Komaba, Tokyo 1538904, Japan.
EM kondo@atmos.rcast.u-tokyo.ac.jp; nakamura@atmos.rcast.u-tokyo.ac.jp;
g.chen@larc.nasa.gov; takegawa@atmos.rcast.u-tokyo.ac.jp;
koike@eps.s.u-tokyo.ac.jp; yuzom@atmos.rcast.u-tokyo.ac.jp;
kita@env.sci.ibaraki.ac.jp; j.h.crawford@larc.nasa.gov;
malcolm.k.ko@larc.nasa.gov; drblake@uci.edu; kawakami.shuji@jaxa.jp;
shirai@eorc.jaxa.jp; b.liley@niwa.co.nz; ywang@eas.gatech.edu;
togawa@eorc.jaxa.jp
RI Koike, Makoto/F-4366-2011; Kondo, Yutaka/D-1459-2012; Miyazaki,
Yuzo/C-6920-2010; Crawford, James/L-6632-2013; Ko, Malcolm/D-5898-2015;
OI Crawford, James/0000-0002-6982-0934; Liley, Ben/0000-0002-8844-7928
NR 43
TC 24
Z9 24
U1 1
U2 8
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 14
PY 2004
VL 109
IS D23
AR D23S02
DI 10.1029/2004JD004871
PG 19
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 863RG
UT WOS:000224578800001
ER
PT J
AU Hill, CJ
Yang, RQ
AF Hill, CJ
Yang, RQ
TI Interband cascade lasers grown on GaAs substrates lasing at 4 microns
SO APPLIED PHYSICS LETTERS
LA English
DT Article
ID ROOM-TEMPERATURE
AB Antimonide-based, type II interband cascade lasers grown on GaAs substrates have been demonstrated at emission wavelengths longer than 4 mum at temperatures up to 270 K in pulsed-mode operation. Investigations by transmission electron microscopy, atomic. force microscopy and x-ray diffraction are presented and discussed to gain insights into material issues such as defects and dislocations associated with device performance. (C) 2004 American Institute Of Physics.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Hill, CJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM cory.j.hill.@jpl.nasa.gov
NR 8
TC 5
Z9 6
U1 0
U2 1
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0003-6951
J9 APPL PHYS LETT
JI Appl. Phys. Lett.
PD OCT 11
PY 2004
VL 85
IS 15
BP 3014
EP 3016
DI 10.1063/1.1803952
PG 3
WC Physics, Applied
SC Physics
GA 865CE
UT WOS:000224679300006
ER
PT J
AU Griaznov, V
Veselovskii, I
Di Girolamo, P
Demoz, B
Whiteman, DN
AF Griaznov, V
Veselovskii, I
Di Girolamo, P
Demoz, B
Whiteman, DN
TI Numerical simulation of light backscattering by spheres with off-center
inclusion. Application to the lidar case
SO APPLIED OPTICS
LA English
DT Article
ID ECCENTRIC INCLUSION; OPTICAL-PROPERTIES; DIELECTRIC SPHERE; BRIGHT BAND;
SCATTERING; RADAR; HYDROMETEORS; CIRRUS; WATER
AB A Mie backscattering model for spherical particles with off-center inclusion has been developed and tested. The program is capable of dealing with size parameter values up to similar to1000, thus allowing one to simulate the optical behavior of a large variety of atmospheric aerosols, as well as cloud and precipitation particles. On the basis of this model, we simulated the optical properties of polydisperse composite atmospheric particles as observed by ground-based and airborne lidar systems. We have characterized optical properties in terms of host and inclusion radii, considering water particles with different composition inclusions. The performed modeling provides some insight into the so-called lidar bright- and dark-band phenomenon. (C) 2004 Optical Society of America.
C1 Inst Gen Phys, Phys Instrumentat Ctr, Troitsk 142190, Moscow Region, Russia.
Univ Basilicata, I-85100 Potenza, Italy.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Griaznov, V (reprint author), Inst Gen Phys, Phys Instrumentat Ctr, Troitsk 142190, Moscow Region, Russia.
EM iveselov@agnes.gsfc.nasa.gov
RI Demoz, Belay/N-4130-2014
NR 19
TC 7
Z9 8
U1 0
U2 3
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 1559-128X
EI 2155-3165
J9 APPL OPTICS
JI Appl. Optics
PD OCT 10
PY 2004
VL 43
IS 29
BP 5512
EP 5522
DI 10.1364/AO.43.005512
PG 11
WC Optics
SC Optics
GA 862RY
UT WOS:000224509800013
PM 15508609
ER
PT J
AU Zhang, PJ
Beacom, JF
AF Zhang, PJ
Beacom, JF
TI Angular correlations of the MeV cosmic gamma-ray background
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE gamma rays : theory; large-scale structure of universe; stars :
formation
ID 3-DIMENSIONAL POWER SPECTRUM; SKY SURVEY DATA; DARK MATTER; SUPERNOVAE;
GALAXIES; CONSTRAINTS; COMPTEL
AB The measured cosmic gamma-ray background (CGB) spectrum at MeV energies is in reasonable agreement with the predicted contribution from Type Ia supernovae (SNe Ia). However, the characteristic features in the SN Ia gamma-ray spectrum, weakened by integration over source redshifts, are difficult to measure, and the contributions from other sources in the MeV range are uncertain, so that the SN Ia origin of the MeV CGB remains unproven. Since different CGB sources have different clustering properties and redshift distributions, by combining the CGB spectrum and angular correlation measurements the contributions to the CGB could be identified and separated. The SN Ia CGB large-scale structure follows that of galaxies. Its rms fluctuation at degree scales has a characteristic energy dependence ranging from similar to1% to on the order of unity and can be measured to several percent precision by proposed future satellites such as the Advanced Compton Telescope. With the identification of the SN Ia contribution, the SN Ia rate could be measured unambiguously as a function of redshift up to z similar to 1 by combining the spectrum and angular correlation measurements, yielding new constraints on the star formation rate to even higher redshifts. Finally, we show that the gamma-ray and neutrino backgrounds from supernovae should be closely connected, allowing an important consistency test from the measured data. Identification of the astrophysical contributions to the CGB would allow much greater sensitivity to an isotropic high-redshift CGB contribution arising in extra dimension or dark matter models.
C1 NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA.
RP Zhang, PJ (reprint author), NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA.
EM zhangpj@fnal.gov; beacom@fnal.gov
RI ZHANG, PENGJIE/O-2825-2015;
OI Beacom, John/0000-0002-0005-2631
NR 45
TC 32
Z9 32
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 10
PY 2004
VL 614
IS 1
BP 37
EP 42
DI 10.1086/423329
PN 1
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 860TT
UT WOS:000224366900006
ER
PT J
AU Bonamente, M
Joy, MK
Carlstrom, JE
Reese, ED
LaRoque, SJ
AF Bonamente, M
Joy, MK
Carlstrom, JE
Reese, ED
LaRoque, SJ
TI Markov Chain Monte Carlo joint analysis of Chandra X-ray imaging
spectroscopy and Sunyaev-Zel'dovich effect data
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE cosmic microwave background; cosmology : observations; distance scale;
galaxies : clusters : general; methods : statistical; techniques :
interferometric
ID PARAMETER-ESTIMATION; CLUSTERS; GALAXIES; SPECTRA; GAS
AB X-ray and Sunyaev-Zel'dovich effect data can be combined to determine the distance to galaxy clusters. High-resolution X-ray data are now available from Chandra, which provides both spatial and spectral information, and Sunyaev-Zel'dovich effect data were obtained from the BIMA and Owens Valley Radio Observatory (OVRO) arrays. We introduce a Markov Chain Monte Carlo procedure for the joint analysis of X-ray and Sunyaev-Zel'dovich effect data. The advantages of this method are the high computational efficiency and the ability to measure simultaneously the probability distribution of all parameters of interest, such as the spatial and spectral properties of the cluster gas and also for derivative quantities such as the distance to the cluster. We demonstrate this technique by applying it to the Chandra X-ray data and the OVRO radio data for the galaxy cluster A611. Comparisons with traditional likelihood ratio methods reveal the robustness of the method. This method will be used in follow-up papers to determine the distances to a large sample of galaxy clusters.
C1 Univ Alabama, Dept Phys, Huntsville, AL 35899 USA.
NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA.
Univ Chicago, Enrico Fermi Inst, Dept Phys, Kavli Inst Cosmol Phys, Chicago, IL 60637 USA.
Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA.
RP Bonamente, M (reprint author), Univ Alabama, Dept Phys, Huntsville, AL 35899 USA.
NR 40
TC 28
Z9 28
U1 0
U2 3
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 10
PY 2004
VL 614
IS 1
BP 56
EP 63
DI 10.1086/423420
PN 1
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 860TT
UT WOS:000224366900009
ER
PT J
AU Francis, PJ
Palunas, P
Teplitz, HI
Williger, GM
Woodgate, BE
AF Francis, PJ
Palunas, P
Teplitz, HI
Williger, GM
Woodgate, BE
TI The distribution of Ly alpha-emitting galaxies at z=2.38. II.
Spectroscopy
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE galaxies : clusters : general; galaxies : high-redshift; large-scale
structure of universe; quasars : general
ID EMITTERS; CLUSTER
AB In Paper 1 of this series we identified an 80 comoving Mpc filament of candidate Lyalpha-emitting galaxies at redshift 2.38. In this paper we present spectroscopy of the 37 galaxy candidates. Our spectroscopy reached a surface brightness limit of 5.0 x 10(-17) ergs cm(-2) s(-1) arcsec(-2). Of the 14 candidates down to this limit, 12 were confirmed to be Lyalpha-emitting galaxies at the filament redshift. We also obtained spectral confirmation for six of the lower surface brightness candidates, all of which also lay at the filament redshift. In addition, we identify a foreground cluster of QSOs at z = 1.65.
C1 Australian Natl Univ, Mt Stromlo Observ, Res Sch Astron & Astrophys, Canberra, ACT 0200, Australia.
Univ Texas, McDonald Observ, Austin, TX 78712 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Australian Natl Univ, Fac Sci, Dept Phys, Canberra, ACT, Australia.
RP Francis, PJ (reprint author), Australian Natl Univ, Mt Stromlo Observ, Res Sch Astron & Astrophys, Cotter Rd, Canberra, ACT 0200, Australia.
EM pfrancis@mso.anu.edu.au
RI Woodgate, Bruce/D-2970-2012
NR 18
TC 18
Z9 18
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 10
PY 2004
VL 614
IS 1
BP 75
EP 83
DI 10.1086/423417
PN 1
PG 9
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 860TT
UT WOS:000224366900012
ER
PT J
AU Padoan, P
Willacy, K
Langer, W
Juvela, M
AF Padoan, P
Willacy, K
Langer, W
Juvela, M
TI Electron abundance in protostellar cores
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE astrochemistry; ISM : clouds; ISM : kinematics and dynamics; ISM :
molecules; radio lines : ISM; turbulence
ID DENSE INTERSTELLAR CLOUDS; MOLECULAR CLOUDS; DARK CLOUDS; DEUTERIUM
FRACTIONATION; IONIZATION FRACTION; STAR-FORMATION; STELLAR CORES;
DEPLETION; GAS; DESORPTION
AB The determination of the fractional electron abundance, x(e), in protostellar cores relies on observations of molecules such as DCO+, (HCO+)-C-13, and CO and on chemical models to interpret their abundance. Studies of protostellar cores have revealed significant variations of x(e) from core to core within a range 10(-8) < x(e) < 10(-6). The physical origin of these large variations in x(e) is not well understood, unless unlikely variations in the cosmic-ray ionization rate or ad hoc values of metal depletion are assumed. In this work we explore other potential causes of these variations in x(e) including core age, extinction, and density. We compute numerically the intensity of the radiation field within a density distribution generated by supersonic turbulence. Taking into account the lines of sight in all directions, the effective visual extinction in dense regions is found to be always much lower than the extinction derived from the column density along a fixed line of sight. Dense cores with volume and column densities comparable to observed protostellar cores have relatively low mass-averaged visual extinction, 2 less than or equal to A(V) less than or equal to 5 mag, such that photoionization can sometimes be as important as cosmic-ray ionization. Chemical models, including gas-grain chemistry and time-dependent gas depletion and desorption, are computed for values of visual extinction in the range 2 less than or equal to A(V) less than or equal to 6 mag and for a hydrogen gas density of 10(4) cm(-3), typical of protostellar cores. The models presented here can reproduce some of the observed variations of ion abundance from core to core as the combined effect of visual extinction and age variations. The range of electron abundances predicted by the models is relatively insensitive to density over 10(4)-10(6) cm(-3).
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Helsinki, Helsinki Univ Observ, SF-00014 Helsinki, Finland.
RP Padoan, P (reprint author), Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA.
RI Juvela, Mika/H-6131-2011;
OI Juvela, Mika/0000-0002-5809-4834; Padoan, Paolo/0000-0002-5055-5800
NR 32
TC 16
Z9 16
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 10
PY 2004
VL 614
IS 1
BP 203
EP 210
DI 10.1086/423659
PN 1
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 860TT
UT WOS:000224366900024
ER
PT J
AU Strohmayer, TE
AF Strohmayer, TE
TI Chandra detection of the AM canum venaticorum binary ES Ceti (KUV
01584-0939)
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE binaries : close; gravitational waves; stars : individual (KUV
01584-0939, ES Ceti, Cetus 3); white dwarfs; X-rays : binaries
ID DOUBLE-DEGENERATE POLAR; SHORTEST PERIOD BINARY; DISK BOUNDARY-LAYERS;
X-RAY-EMISSION; CATACLYSMIC VARIABLES; RX J1914.4+2456; ORBITAL PERIOD;
SPIN-UP; J0806.3+1527; ROSAT
AB We report on Chandra ACIS observations of the ultracompact AM CVn binary ES Cet. This object has a 10.3 minute binary period and is the most compact of the confirmed AM CVn systems. We have, for the first time, unambiguously detected the X-ray counterpart to ES Cet. In a 20 ks ACIS-S image a point-like X-ray source is found within 1" of the cataloged optical position. The mean count rate in ACIS-S is 0.013 s(-1), and there is no strong evidence for variability. We folded the X-ray data using the optical ephemeris of Warner & Woudt, but did not detect any significant modulation. If a similar to100% modulation similar to those seen in the ultracompact candidates V407 Vul and RX J0806.3+1527 were present, then we would have detected it. The upper limit (3 sigma) to any modulation at the putative orbital period is similar to15% (rms). We extract the first X-ray spectrum from ES Cet, and find that it is not well described by simple continuum models. We find suggestive evidence for discrete spectral components at similar to470 and 890 eV that can be modeled as Gaussian emission lines. In comparison with recent X-ray detections of nitrogen and neon in another AM CVn system (GP Com), it appears possible that these features may represent emission lines from these same elements; however, deeper spectroscopy will be required to confirm this. Our best spectral model includes a blackbody continuum with kT=0.8 keV along with the Gaussian lines. The unabsorbed 0.2-5 keV X-ray flux was similar to7x10(-14) ergs cm(-2) s(-1). The observed luminosity in the hard component is a small fraction of the total expected accretion luminosity, most of which should be radiated below 0.1 keV at the expected mass accretion rate for this orbital period. We discuss the implications of our results for the nature of ES Cet.
C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
RP Strohmayer, TE (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
EM stroh@clarence.gsfc.nasa.gov
NR 33
TC 5
Z9 5
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 10
PY 2004
VL 614
IS 1
BP 358
EP 362
DI 10.1086/423615
PN 1
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 860TT
UT WOS:000224366900038
ER
PT J
AU Gould, A
Bennett, DP
Alves, DR
AF Gould, A
Bennett, DP
Alves, DR
TI The mass of the MACHO-LMC-5 lens star
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE gravitational lensing; stars : fundamental parameters; stars : low-mass,
brown dwarfs
ID LARGE-MAGELLANIC-CLOUD; GRAVITATIONAL MICROLENSING EVENTS;
SPACE-INTERFEROMETRY-MISSION; MACHO PHOTOMETRY; HIPPARCOS DATA;
PARALLAXES; KINEMATICS; ASTROMETRY
AB We combine the available astrometric and photometric data for the 1993 microlensing event MACHO-LMC-5 to measure the mass of the lens, M=0.097+/-0.016 M-circle dot. This is the most precise direct mass measurement of a single star other than the Sun. In principle, the measurement error could be reduced as low as 10% by improving the trigonometric parallax measurement using, for example, the Space Interferometry Mission. Further improvements might be possible by rereducing the original photometric light curve using image subtraction or by obtaining new, higher precision baseline photometry of the source. We show that the current data strongly limit scenarios in which the lens is a dark (i.e., brown dwarf) companion to the observed M dwarf rather than being the M dwarf itself. These results set the stage for a confrontation between mass estimates of the M dwarf obtained from spectroscopic and photometric measurements and a mass measurement derived directly from the star's gravitational influence. This would be the first such confrontation for any isolated star other than the Sun.
C1 Ohio State Univ, Dept Astron, Columbus, OH 43210 USA.
Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA.
Columbia Univ, Dept Astron, New York, NY 10027 USA.
NASA, Natl Res Council, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Gould, A (reprint author), Ohio State Univ, Dept Astron, 140 W 18th Ave, Columbus, OH 43210 USA.
EM gould@astronomy.ohio-state.edu; bennett@nd.edu;
alves@lasp680.gsfc.nasa.gov
NR 39
TC 35
Z9 35
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 10
PY 2004
VL 614
IS 1
BP 404
EP 411
DI 10.1086/423614
PN 1
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 860TT
UT WOS:000224366900044
ER
PT J
AU Cuzzi, JN
Zahnle, KJ
AF Cuzzi, JN
Zahnle, KJ
TI Material enhancement in protoplanetary nebulae by particle drift through
evaporation fronts
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE accretion, accretion disks; diffusion; planetary systems :
protoplanetary disks; solar system : formation; turbulence
ID SOLAR NEBULA; ICY PLANETESIMALS; ACCRETION; ORIGIN; DISK; CHONDRULES;
EVOLUTION; JUPITER; DUST; REDISTRIBUTION
AB Solid material in a protoplanetary nebula is subject to vigorous redistribution processes relative to the nebula gas. Meter-sized particles drift rapidly inward near the nebula midplane, and material evaporates when the particles cross a condensation/evaporation boundary. The material cannot be removed as fast in its vapor form as it is being supplied in solid form, so its concentration increases locally by a large factor (more than an order of magnitude under nominal conditions). As time goes on, the vapor-phase enhancement propagates for long distances inside the evaporation boundary (potentially all the way into the star). Meanwhile, material is enhanced in its solid form over a characteristic length scale outside the evaporation boundary. This effect is applicable to any condensible (water, silicates, etc.). Three distinct radial enhancement/ depletion regimes can be discerned by use of a simple model. Meteoritic applications include oxygen fugacity and isotopic variations, as well as isotopic homogenization in silicates. Planetary system applications include more robust enhancement of solids in Jupiter's core formation region than previously suggested. Astrophysical applications include differential, time-dependent enhancement of vapor phase CO and H2O in the terrestrial planet regions of actively accreting protoplanetary disks.
C1 NASA, Div Space Sci, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Cuzzi, JN (reprint author), NASA, Div Space Sci, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA.
EM jcuzzi@mail.arc.nasa.gov; kzahnle@mail.arc.nasa.gov
NR 42
TC 81
Z9 82
U1 0
U2 6
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 10
PY 2004
VL 614
IS 1
BP 490
EP 496
DI 10.1086/423611
PN 1
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 860TT
UT WOS:000224366900052
ER
PT J
AU Wang, DY
Stiller, GP
von Clarmann, T
Fischer, H
Lopez-Puertas, M
Funke, B
Glatthor, N
Grabowski, U
Hopfner, M
Kellmann, S
Kiefer, M
Linden, A
Tsidu, GM
Milz, M
Steck, T
Jiang, JH
Ao, CO
Manney, G
Hocke, K
Wu, DL
Romans, LJ
Wickert, J
Schmidt, T
AF Wang, DY
Stiller, GP
von Clarmann, T
Fischer, H
Lopez-Puertas, M
Funke, B
Glatthor, N
Grabowski, U
Hopfner, M
Kellmann, S
Kiefer, M
Linden, A
Tsidu, GM
Milz, M
Steck, T
Jiang, JH
Ao, CO
Manney, G
Hocke, K
Wu, DL
Romans, LJ
Wickert, J
Schmidt, T
TI Cross-validation of MIPAS/ENVISAT and GPS-RO/CHAMP temperature profiles
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE CHAMP; MIPAS; temperature
ID RADIO OCCULTATION MEASUREMENTS; ATMOSPHERE; GPS/MET; INVERSION
AB The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on board the ENVISAT and the Global Positioning System (GPS) receiver on the Challenging Mini-Satellite Payload (CHAMP) provide temperature profiles by limb-viewing midinfrared emission and radio occultation (RO) measurements, respectively. The MIPAS temperatures retrieved at the Institut fur Meteorologie und Klimaforschung (IMK) are compared with the GPS-RO/CHAMP observations derived at Jet Propulsion Laboratory (JPL) and GeoForschungsZentrum (GFZ) Potsdam. The three data sets show generally good agreement. The global mean differences averaged between 8 and 30 km in 14 days of September/October 2002 are -0.44 +/- 0.02 K and 0.07 +/- 0.02 K for MIPAS/GPS-RO JPL and GFZ comparisons, respectively. The MIPAS global mean temperatures below 25 km are slightly lower than those of GPS-RO JPL and GFZ by less than 1 K and 0.2 K, respectively. Above 25 km, the MIPAS temperatures are higher than the JPL and GFZ data, in particular near both poles and the equator, with maxima of 1 K for JPL and 1.5 K for GFZ at 30 km. The standard deviations are similar to2-4 K. Possible explanations for the observed differences include (1) effect of spatial and temporal mismatch between the correlative measurements on the observed standard deviations, in particular in regions and episodes of enhanced wave activity; (2) a negative bias in GPS-RO/CHAMP temperatures in regions of increased humidity; (3) a mapping of initialization temperature profiles on GPS-RO/CHAMP retrievals at altitudes where low refraction contains no information on air density; and (4) measurement errors of both instruments, particularly the errors due to insufficient knowledge of the instrument line shape and spectroscopy in current MIPAS retrievals.
C1 Forschungszentrum Karlsruhe, Inst Meteorol & Klimaforsch, D-76021 Karlsruhe, Germany.
Univ Karlsruhe, D-76021 Karlsruhe, Germany.
CSIC, Inst Astrofis Andalucia, E-18008 Granada, Spain.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
New Mexico Highlands Univ, Dept Nat Sci, Los Vegas, NM USA.
Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany.
Geoforschungszentrum Potsdam, Dept Geodesy & Remote Sensing 1, D-14473 Potsdam, Germany.
RP Forschungszentrum Karlsruhe, Inst Meteorol & Klimaforsch, Postfach 3640, D-76021 Karlsruhe, Germany.
EM ding-yi.wang@imk.fzk.de
RI Milz, Mathias/C-9899-2011; Schmidt, Torsten/A-7142-2013; Hopfner,
Michael/A-7255-2013; Stiller, Gabriele/A-7340-2013; von Clarmann,
Thomas/A-7287-2013; Glatthor, Norbert/B-2141-2013; Kiefer,
Michael/A-7254-2013; Wickert, Jens/A-7257-2013; Lopez Puertas,
Manuel/M-8219-2013; Funke, Bernd/C-2162-2008; Wu, Dong/D-5375-2012
OI Milz, Mathias/0000-0002-4478-2185; Schmidt, Torsten/0000-0001-9302-1000;
Hopfner, Michael/0000-0002-4174-9531; Stiller,
Gabriele/0000-0003-2883-6873; von Clarmann, Thomas/0000-0003-2219-3379;
Lopez Puertas, Manuel/0000-0003-2941-7734; Funke,
Bernd/0000-0003-0462-4702;
NR 36
TC 20
Z9 20
U1 0
U2 4
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 9
PY 2004
VL 109
IS D19
AR D19311
DI 10.1029/2004JD004963
PG 15
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 861PR
UT WOS:000224430000006
ER
PT J
AU Montmessin, F
Forget, F
Rannou, P
Cabane, M
Haberle, RM
AF Montmessin, F
Forget, F
Rannou, P
Cabane, M
Haberle, RM
TI Origin and role of water ice clouds in the Martian water cycle as
inferred from a general circulation model
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
DE clouds; Mars; water cycle
ID THERMAL EMISSION SPECTROMETER; HUBBLE-SPACE-TELESCOPE; MARS ORBITER
CAMERA; NORTH POLAR HOOD; ATMOSPHERIC OBSERVATIONS; MAPPER OBSERVATIONS;
HYDROLOGIC-CYCLE; VARIABILITY; REGIONS; VAPOR
AB In this paper, we present the results obtained by the general circulation model developed at the Laboratoire de Meteorologie Dynamique which has been used to simulate the Martian hydrological cycle. Our model, which employs a simplified cloud scheme, reproduces the observed Martian water cycle with unprecedented agreement. The modeled seasonal evolution of cloudiness, which also compares well with data, is described in terms of the meteorological phenomena that control the Martian cloud distribution. Whereas cloud formation in the tropical region results from seasonal changes in the overturning circulation, Polar Hood clouds are mostly driven by variations of atmospheric wave activity. A sensitivity study allows us to quantify the effects of the transport of water ice clouds on the seasonal evolution of the water cycle. The residence time of cloud particles is long enough to allow cloud advection over great distances (typically thousands of kilometers). Despite the relatively low proportion of clouds (similar to10%) in the total atmospheric inventory of water, their ability to be transported over large distances generally acts at the expense of the north polar cap and generates a water cycle globally wetter by a factor of 2 than a cycle produced by a model neglecting cloud transport. Around aphelion season, clouds modulate the north to south migration of water in a significant fashion and participate just as much as vapor in the cross-equatorial transport of total water. Most of the year, atmospheric waves generate an equatorward motion of water ice clouds near the polar vortex boundaries, partially balancing the opposite poleward flux of water vapor. The combination of both effects delays the return of water to the north polar cap and allows water to build up in the Martian tropics.
C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA.
Univ Paris 06, Inst Pierre Simon Laplace, Meteorol Dynam Lab, F-75252 Paris 05, France.
Univ Paris 06, Inst Pierre Simon Laplace, Serv Aeron, F-75252 Paris 05, France.
RP Montmessin, F (reprint author), NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA.
EM fmontmessin@mail.arc.nasa.gov
RI RANNOU, Pascal/I-9059-2012
NR 61
TC 146
Z9 146
U1 3
U2 16
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9097
EI 2169-9100
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD OCT 9
PY 2004
VL 109
IS E10
AR E10004
DI 10.1029/2004JE002284
PG 26
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 861PX
UT WOS:000224430600001
ER
PT J
AU Neugebauer, M
Liewer, PC
Goldstein, BE
Zhou, X
Steinberg, JT
AF Neugebauer, M
Liewer, PC
Goldstein, BE
Zhou, X
Steinberg, JT
TI Solar wind stream interaction regions without sector boundaries
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
DE interaction regions; solar wind
ID ION COMPOSITION SPECTROMETER; HELIOSPHERIC PLASMA SHEET; CORONAL
STREAMERS; MAGNETIC-FIELDS; FLOWS; SPEED; HOLES
AB During periods of high solar activity when there are many sources of solar wind on the solar disk, a spacecraft occasionally encounters consecutive solar wind streams with the same magnetic polarity. The low-speed wind in the region of interaction between the two streams exhibits many of the same features as, but has some differences from, the low-speed wind that includes crossings of the heliospheric current sheet (HCS) where the direction of the heliospheric magnetic field reverses. The non-HCS slow wind exhibits many of the same small-scale structures usually associated with the slow wind around the HCS; these include discontinuous stream interfaces and other discontinuities, magnetic holes, and low-entropy structures. These entropy holes do not appear to have the same origin as the plasma sheets observed near the HCS, however. The helium abundances and heavy ion charge states in the non-HCS regions are not significantly different from those in HCS-associated regions. Some of the dynamical properties of the non-HCS regions differ from those found near the HCS; the regions between leading and trailing stream interfaces have a shorter duration or scale size, greater minimum speed, and lower peak and average densities. No correlation could be found between the non-HCS slow wind and visible coronal streamers.
C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Los Alamos Natl Lab, Los Alamos, NM 87545 USA.
RP Neugebauer, M (reprint author), Univ Arizona, Lunar & Planetary Lab, Bldg 92,1629 E Univ Blvd, Tucson, AZ 85721 USA.
EM mneugeb@lpl.arizona.edu; paulett.liewer@jpl.nasa.gov;
bruce.goldstein@jpl.nasa.gov; xiaoyan.zhou@jpl.nasa.gov;
jsteinberg@lanl.gov
NR 29
TC 35
Z9 35
U1 1
U2 4
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD OCT 9
PY 2004
VL 109
IS A10
AR A10102
DI 10.1029/2004JA010456
PG 10
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 861QD
UT WOS:000224431300001
ER
PT J
AU Carn, SA
Krueger, AJ
Krotkov, NA
Gray, MA
AF Carn, SA
Krueger, AJ
Krotkov, NA
Gray, MA
TI Fire at Iraqi sulfur plant emits SO2 clouds detected by Earth Probe TOMS
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
AB A fire started at the Al-Mishraq State Sulfur plant near Mosul, Iraq on 24 June 2003 and burned for almost a month. Combustion of elemental sulfur in the fire produced dense clouds of sulfur dioxide (SO2) that were detected from space by the Earth Probe Total Ozone Mapping Spectrometer (EP TOMS) on 18 days. Estimated daily SO2 production from the continuously emitting source closely mirrors contemporaneous thermal infrared radiance from the fire sensed in the 3.96 mm band of the Moderate Resolution Imaging Spectroradiometer ( MODIS). We calculate total SO2 production during the blaze amounting to similar to600 kilotons, which is roughly commensurate with the predicted SO2 yield from the inventory of elemental sulfur allegedly destroyed by the fire when potential SO2 losses are considered. This event is the largest non-volcanic SO2 emission incident measured to date by any TOMS instrument.
C1 Univ Maryland Baltimore Cty, NASA, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA.
Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA.
L3 Commun Govt Serv Inc, Largo, MD USA.
RP Carn, SA (reprint author), Univ Maryland Baltimore Cty, NASA, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA.
EM scarn@umbc.edu
RI Krotkov, Nickolay/E-1541-2012
OI Krotkov, Nickolay/0000-0001-6170-6750
NR 9
TC 26
Z9 29
U1 0
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 8
PY 2004
VL 31
IS 19
AR L19105
DI 10.1029/2004GL020719
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 861PK
UT WOS:000224429300006
ER
PT J
AU Yung, YL
Liang, MC
Blake, GA
Muller, RP
Miller, CE
AF Yung, YL
Liang, MC
Blake, GA
Muller, RP
Miller, CE
TI Evidence for O-atom exchange in the O(D-1)+N2O reaction as the source of
mass-independent isotopic fractionation in atmospheric N2O
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID NITROUS-OXIDE; O-17/O-16 RATIOS; CARBON-DIOXIDE; OZONE; O-18/O-16
AB Recent experiments have shown that in the oxygen isotopic exchange reaction for O(D-1) + CO2 the elastic channel is approximately 50% that of the inelastic channel [Perri et al., 2003]. We propose an analogous oxygen atom exchange reaction for the isoelectronic O(D-1) + N2O system to explain the mass-independent isotopic fractionation (MIF) in atmospheric N2O. We apply quantum chemical methods to compute the energetics of the potential energy surfaces on which the O(D-1) + N2O reaction occurs. Preliminary modeling results indicate that oxygen isotopic exchange via O(D-1) + N2O can account for the MIF oxygen anomaly if the oxygen atom isotopic exchange rate is 30-50% that of the total rate for the reactive channels.
C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA.
Sandia Natl Labs, Albuquerque, NM 87185 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Yung, YL (reprint author), CALTECH, Div Geol & Planetary Sci, MS 150-21,1200 E Calif Blvd, Pasadena, CA 91125 USA.
EM mcl@gps.caltech.edu
NR 23
TC 7
Z9 7
U1 2
U2 9
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 8
PY 2004
VL 31
IS 19
AR L19106
DI 10.1029/2004GL020950
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 861PK
UT WOS:000224429300008
ER
PT J
AU Gutsev, GL
Mochena, MD
Jena, P
Bauschlicher, CW
Partridge, H
AF Gutsev, GL
Mochena, MD
Jena, P
Bauschlicher, CW
Partridge, H
TI Periodic table of 3d-metal dimers and their ions
SO JOURNAL OF CHEMICAL PHYSICS
LA English
DT Article
ID TRANSITION-METAL DIATOMICS; ELECTRON-SPIN-RESONANCE; DENSITY-FUNCTIONAL
THEORY; CORRELATION-ENERGY; IONIZATION ENERGIES; GROUND-STATES;
BASIS-SETS; ROW ATOMS; MOLECULES; SPECTROSCOPY
AB The ground states of the mixed 3d-metal dimers TiV, TiCr, TiMn, TiFe, TiCo, TiNi, TiCu, TiZn, VCr, VMn, VFe, VCo, VNi, VCu, VZn, CrMn, CrFe, CrCo, CrNi, CrCu, CrZn, MnFe, MnCo, MnNi, MnCu, MnZn, FeCo, FeNi, FeCu, FeZn, CoNi, CoCu, CoZn, NiCu, NiZn, and CuZn along with their singly negatively and positively charged ions are assigned based on the results of computations using density functional theory with generalized gradient approximation for the exchange-correlation functional. Except for TiCo and CrMn, our assignment agrees with experiment. Computed spectroscopic constants (r(e),omega(e),D-o) are in fair agreement with experiment. The ground-state spin multiplicities of all the ions are found to differ from the spin multiplicities of the corresponding neutral parents by +/-1. Except for TiV, MnFe, and MnCu, the number of unpaired electrons, N, in a neutral ground-state dimer is either N-1+N-2 or \N-1-N-2\, where N-1 and N-2 are the numbers of unpaired 3d electrons in the 3d(n)4s(1) occupation of the constituent atoms. Combining the present and previous results obtained at the same level of theory for homonuclear [Gutsev and Bauschlicher, J. Phys. Chem. A 107, 4755 (2003)] 3d-metal and ScX (X=Ti-Zn) dimers [Gutsev, Bauschlicher, and Andrews, in Theoretical Prospects of Negative Ions, edited by J. Kalcher (Research Signpost, Trivandrum, 2002), pp. 43-60] allows one to construct "periodic" tables of all 3d-metal dimers along with their singly charged ions. (C) 2004 American Institute of Physics.
C1 Florida A&M Univ, Dept Phys, Tallahassee, FL 32307 USA.
Virginia Commonwealth Univ, Dept Phys, Richmond, VA 23284 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Gutsev, GL (reprint author), Florida A&M Univ, Dept Phys, Tallahassee, FL 32307 USA.
EM gennady.gutsev@famu.edu
NR 62
TC 53
Z9 53
U1 0
U2 19
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0021-9606
J9 J CHEM PHYS
JI J. Chem. Phys.
PD OCT 8
PY 2004
VL 121
IS 14
BP 6785
EP 6797
DI 10.1063/1.1788656
PG 13
WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical
SC Chemistry; Physics
GA 859MV
UT WOS:000224269200025
PM 15473736
ER
PT J
AU Thomas, R
Rignot, E
Casassa, G
Kanagaratnam, P
Acuna, C
Akins, T
Brecher, H
Frederick, E
Gogineni, P
Krabill, W
Manizade, S
Ramamoorthy, H
Rivera, A
Russell, R
Sonntag, J
Swift, R
Yungel, J
Zwally, J
AF Thomas, R
Rignot, E
Casassa, G
Kanagaratnam, P
Acuna, C
Akins, T
Brecher, H
Frederick, E
Gogineni, P
Krabill, W
Manizade, S
Ramamoorthy, H
Rivera, A
Russell, R
Sonntag, J
Swift, R
Yungel, J
Zwally, J
TI Accelerated sea-level rise from West Antarctica
SO SCIENCE
LA English
DT Article
ID PINE ISLAND GLACIER; GREENLAND ICE-SHEET; AMUNDSEN SEA; POLAR ICE;
THICKNESS; BALANCE; RETREAT; MODEL
AB Recent aircraft and satellite laser altimeter surveys of the Amundsen Sea sector of West Antarctica show that local glaciers are discharging about 250 cubic kilometers of ice per year to the ocean, almost 60% more than is accumulated within their catchment basins. This discharge is sufficient to raise sea level by more than 0.2 millimeters per year. Glacier thinning rates near the coast during 2002-2003 are much larger than those observed during the 1990s. Most of these glaciers flow into floating ice shelves over bedrock up to hundreds of meters deeper than previous estimates, providing exit routes for ice from further inland if ice-sheet collapse is under way.
C1 NASA, Goddard Space Flight Ctr, EG&G Inc, Wallops Flight Facil, Wallops Isl, VA 23337 USA.
Ctr Estudios Cient, Valdivia, Chile.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Kansas, Radar Syst & Remote Sensing Lab, Lawrence, KS 66045 USA.
Ohio State Univ, Byrd Polar Res Ctr, Columbus, OH 43210 USA.
Univ Chile, Dept Geog, Santiago, Chile.
RP Thomas, R (reprint author), NASA, Goddard Space Flight Ctr, EG&G Inc, Wallops Flight Facil, Bldg N-159, Wallops Isl, VA 23337 USA.
EM thomas@osb.wff.nasa.gov
RI Rignot, Eric/A-4560-2014;
OI Rignot, Eric/0000-0002-3366-0481; Rivera, Andres/0000-0002-2779-4192
NR 27
TC 215
Z9 225
U1 3
U2 26
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
J9 SCIENCE
JI Science
PD OCT 8
PY 2004
VL 306
IS 5694
BP 255
EP 258
DI 10.1126/science.1099650
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 861MC
UT WOS:000224419700033
PM 15388895
ER
PT J
AU Lockitch, KH
Andersson, N
Watts, AL
AF Lockitch, KH
Andersson, N
Watts, AL
TI Regularizing the r-mode problem for nonbarotropic relativistic stars
SO CLASSICAL AND QUANTUM GRAVITY
LA English
DT Article
ID ROTATING SPHERICAL-SHELLS; COWLING APPROXIMATION; DRIVEN INSTABILITY;
SPECTRUM; OSCILLATIONS; STABILITY
AB We present results for r-modes of relativistic nonbarotropic stars. We show that the main differential equation, which is formally singular at lowest order in the slow-rotation expansion, can be regularized if one considers the initial value problem rather than the normal mode problem. However, a more physically motivated way to regularize the problem is to include higher order terms. This allows us to develop a practical approach for solving the problem and we provide results that support earlier conclusions obtained for uniform density stars. In particular, we show that there will exist a single r-mode for each permissible combination of l and m. We discuss these results and provide some caveats regarding their usefulness for estimates of gravitational-radiation reaction timescales. The close connection between the seemingly singular relativistic r-mode problem and issues arising because of the presence of corotation points in differentially rotating stars is also clarified.
C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA.
Univ Southampton, Sch Math, Southampton SO17 1BJ, Hants, England.
NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
RP Lockitch, KH (reprint author), Univ Illinois, Dept Phys, 1110 E Green St, Urbana, IL 61801 USA.
EM na@maths.soton.ac.uk; anna@mitkyway.gsfc.nasa.gov
NR 25
TC 9
Z9 9
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0264-9381
J9 CLASSICAL QUANT GRAV
JI Class. Quantum Gravity
PD OCT 7
PY 2004
VL 21
IS 19
BP 4661
EP 4675
AR PII S0264-9381(04)8116-X
DI 10.1088/0264-9381/21/19/021
PG 15
WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles
& Fields
SC Astronomy & Astrophysics; Physics
GA 867ZJ
UT WOS:000224881300012
ER
PT J
AU Reichle, RH
Koster, RD
AF Reichle, RH
Koster, RD
TI Bias reduction in short records of satellite soil moisture
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID RETRIEVAL; ASSIMILATION; METHODOLOGY; SIMULATIONS; IMPACT; MODELS
AB Although surface soil moisture data from different sources (satellite retrievals, ground measurements, and land model integrations of observed meteorological forcing data) have been shown to contain consistent and useful information in their seasonal cycle and anomaly signals, they typically exhibit very different mean values and variability. These biases pose a severe obstacle to exploiting the useful information contained in satellite retrievals through data assimilation. A simple method of bias removal is to match the cumulative distribution functions (cdf) of the satellite and model data. However, accurate cdf estimation typically requires a long record of satellite data. We demonstrate here that by using spatial sampling with a 2 degree moving window we can obtain local statistics based on a one-year satellite record that are a good approximation to those that would be derived from a much longer time series. This result should increase the usefulness of relatively short satellite data records.
C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA.
Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
RP Reichle, RH (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Code 900-3, Greenbelt, MD 20771 USA.
EM reichle@gmao.gsfc.nasa.gov
RI Reichle, Rolf/E-1419-2012; Koster, Randal/F-5881-2012
OI Koster, Randal/0000-0001-6418-6383
NR 19
TC 177
Z9 179
U1 3
U2 31
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 6
PY 2004
VL 31
IS 19
AR L19501
DI 10.1029/2004GL020938
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 861PH
UT WOS:000224429000006
ER
PT J
AU Zhang, YC
Rossow, WB
Lacis, AA
Oinas, V
Mishchenko, MI
AF Zhang, YC
Rossow, WB
Lacis, AA
Oinas, V
Mishchenko, MI
TI Calculation of radiative fluxes from the surface to top of atmosphere
based on ISCCP and other global data sets: Refinements of the radiative
transfer model and the input data
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE Earth radiation budget; surface radiation budget (SRB); cloud vertical
structure; ERBE; CERES; BSRN
ID CLOUD VERTICAL STRUCTURE; WATER-VAPOR; GENERAL-CIRCULATION; CONTINUUM
ABSORPTION; GODDARD-INSTITUTE; ENERGY BUDGET; GISS GCM; SATELLITE;
CLIMATE; SENSITIVITY
AB We continue reconstructing Earth's radiation budget from global observations in as much detail as possible to allow diagnosis of the effects of cloud ( and surface and other atmospheric constituents) variations on it. This new study was undertaken to reduce the most noticeable systematic errors in our previous results ( flux data set calculated mainly using International Satellite Cloud Climatology Project-Cl input data (ISCCP-FC)) by exploiting the availability of a more advanced NASA Goddard Institute for Space Studies (GISS) radiative transfer model and improved ISCCP cloud climatology and ancillary data sets. The most important changes are the introduction of a better treatment of ice clouds, revision of the aerosol climatology, accounting for diurnal variations of surface skin/air temperatures and the cloud-radiative effects on them, revision of the water vapor profiles used, and refinement of the land surface albedos and emissivities. We also extend our previous flux results, limited to the top of atmosphere (TOA) and surface (SRF), to also include three levels within the atmosphere, forming one integrated vertical atmospheric flux profile from SRF to TOA, inclusive, by combining a new climatology of cloud vertical structure with the ISCCP cloud product. Using the new radiative transfer model and new input data sets, we have produced an 18-year at 3-hour time steps, global at 280-km intervals, radiative flux profile data set (called ISCCP-FD) that provides full- and clear-sky, shortwave and longwave, upwelling and downwelling fluxes at five levels ( SRF, 680 mbar, 440 mbar, 100 mbar, and TOA). Evaluation is still only possible for TOA and SRF fluxes: Comparisons of monthly, regional mean values from FD with Earth Radiation Budget Experiment, Clouds and the Earth's Radiant Energy System and Baseline Surface Radiation Network values suggest that we have been able to reduce the overall uncertainties from 10-15 to 5-10 W/m(2) at TOA and from 20-25 to 10 15 W/m(2) at SRF. Annual mean pressure-latitude cross sections of the cloud effects on atmospheric net radiative fluxes show that clouds shift the longwave cooling downward in the Intertropical Convergence Zone, acting to stabilize the tropical atmosphere while increasing the horizontal heating gradient forcing the Hadley circulation, and shift the longwave cooling upward in the midlatitude storm zones, acting to destabilize the baroclinic zones while decreasing the horizontal heating gradient there.
C1 Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10032 USA.
NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
Stinger Ghaffarian Technol Inc, New York, NY 10025 USA.
RP Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10032 USA.
EM yzhang@giss.nasa.gov
RI Lacis, Andrew/D-4658-2012; Rossow, William/F-3138-2015
NR 74
TC 603
Z9 614
U1 6
U2 20
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 6
PY 2004
VL 109
IS D19
AR D19105
DI 10.1029/2003JD004457
PG 27
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 861PO
UT WOS:000224429700004
ER
PT J
AU Rouse, JH
Lillehei, PT
Sanderson, J
Siochi, EJ
AF Rouse, JH
Lillehei, PT
Sanderson, J
Siochi, EJ
TI Polymer/single-walled carbon nanotube films assembled via donor-acceptor
interactions and their use as scaffolds for silica deposition
SO CHEMISTRY OF MATERIALS
LA English
DT Article
ID CHARGE-TRANSFER INTERACTION; THIN-FILMS; COMPOSITES; LAYER; DISPERSION;
SUBSTRATE; SURFACE; FIBERS; FUNCTIONALIZATION; CONSTRUCTION
AB A method of stepwise assembling thin polymer/single-walled carbon nanotube (SWCNT) films using donor-acceptor interactions is demonstrated. When the affinity that amine groups have for nanotubes were utilized, films were formed by the sequential adsorption of polyethylenimine and polyallylamine followed by SWCNTs onto silicon substrates. In an effort to expand this methodology to more thermally and oxidatively stable polymer systems, the ability of the basic nitrogen of the pyridine ring to adsorb SWCNTs was also investigated. These studies demonstrated that the nonsterically hindered, para-substituted pyridine in poly(4-vinylpyridine) (P4VP) also has an affinity for SWCNTs, thus enabling the stepwise formation of P4VP/SWCNT films. Microscopy of the films revealed that they were formed of single tubes and small bundles and that film coverage and thickness were uniform. The ability to use these films as scaffolds for the synthesis of novel hybrid structures is demonstrated by modifying the P4VP films using sol-gel chemistry.
C1 Natl Inst Aerosp, Hampton, VA 23666 USA.
NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA.
New Horizons Reg Governors Sch Sci & Technol, Hampton, VA 23665 USA.
RP Rouse, JH (reprint author), Natl Inst Aerosp, 144 Res Dr, Hampton, VA 23666 USA.
EM j.h.rouse@larc.nasa.gov
RI Lillehei, Peter/C-9196-2009
OI Lillehei, Peter/0000-0001-8183-9980
NR 61
TC 45
Z9 47
U1 1
U2 16
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 0897-4756
J9 CHEM MATER
JI Chem. Mat.
PD OCT 5
PY 2004
VL 16
IS 20
BP 3904
EP 3910
DI 10.1021/cm049708t
PG 7
WC Chemistry, Physical; Materials Science, Multidisciplinary
SC Chemistry; Materials Science
GA 858JH
UT WOS:000224187600016
ER
PT J
AU Kahn, R
Anderson, J
Anderson, TL
Bates, T
Brechtel, F
Carrico, CM
Clarke, A
Doherty, SJ
Dutton, E
Flagan, R
Frouin, R
Fukushima, H
Holben, B
Howell, S
Huebert, B
Jefferson, A
Jonsson, H
Kalashnikova, O
Kim, J
Kim, SW
Kus, P
Li, WH
Livingston, JM
McNaughton, C
Merrill, J
Mukai, S
Murayama, T
Nakajima, T
Quinn, P
Redemann, J
Rood, M
Russell, P
Sano, I
Schmid, B
Seinfeld, J
Sugimoto, N
Wang, J
Welton, EJ
Won, JG
Yoon, SC
AF Kahn, R
Anderson, J
Anderson, TL
Bates, T
Brechtel, F
Carrico, CM
Clarke, A
Doherty, SJ
Dutton, E
Flagan, R
Frouin, R
Fukushima, H
Holben, B
Howell, S
Huebert, B
Jefferson, A
Jonsson, H
Kalashnikova, O
Kim, J
Kim, SW
Kus, P
Li, WH
Livingston, JM
McNaughton, C
Merrill, J
Mukai, S
Murayama, T
Nakajima, T
Quinn, P
Redemann, J
Rood, M
Russell, P
Sano, I
Schmid, B
Seinfeld, J
Sugimoto, N
Wang, J
Welton, EJ
Won, JG
Yoon, SC
TI Environmental snapshots from ACE-Asia
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE aerosols; environmental snapshots; dust; pollution; atmospheric closure
ID AEROSOL OPTICAL-PROPERTIES; SUN PHOTOMETER MEASUREMENTS; LOWER
TROPOSPHERIC AEROSOL; SKY RADIANCE MEASUREMENTS; GROUND-BASED
MEASUREMENTS; AIRBORNE IN-SITU; WATER-VAPOR; RADIATIVE PROPERTIES;
PARTICLE-SIZE; MAUNA-LOA
AB On five occasions spanning the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) field campaign in spring 2001, the Multiangle Imaging Spectroradiometer spaceborne instrument took data coincident with high-quality observations by instruments on two or more surface and airborne platforms. The cases capture a range of clean, polluted, and dusty aerosol conditions. With a three-stage optical modeling process, we synthesize the data from over 40 field instruments into layer-by-layer environmental snapshots that summarize what we know about the atmospheric and surface states at key locations during each event. We compare related measurements and discuss the implications of apparent discrepancies, at a level of detail appropriate for satellite retrieval algorithm and aerosol transport model validation. Aerosols within a few kilometers of the surface were composed primarily of pollution and Asian dust mixtures, as expected. Medium- and coarse-mode particle size distributions varied little among the events studied; however, column aerosol optical depth changed by more than a factor of 4, and the near-surface proportion of dust ranged between 25% and 50%. The amount of absorbing material in the submicron fraction was highest when near-surface winds crossed Beijing and the Korean Peninsula and was considerably lower for all other cases. Having simultaneous single-scattering albedo measurements at more than one wavelength would significantly reduce the remaining optical model uncertainties. The consistency of component particle microphysical properties among the five events, even in this relatively complex aerosol environment, suggests that global, satellite-derived maps of aerosol optical depth and aerosol mixture (air-mass-type) extent, combined with targeted in situ component microphysical property measurements, can provide a detailed global picture of aerosol behavior.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Arizona State Univ, Dept Mech & Aerosp Engn, Tempe, AZ 85287 USA.
Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA.
NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA.
Brechtel Mfg Inc, Hayward, CA 94544 USA.
Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA.
Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA.
NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA.
CALTECH, Dept Chem Engn, Pasadena, CA 91125 USA.
Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92037 USA.
Tokai Univ, Sch High Technol Human Welf, Numazu 4100395, Japan.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
USN, Postgrad Sch, CIRPAS, Marina, CA 93933 USA.
Korea Meteorol Adm, Meteorol Res Inst, Seoul 156720, South Korea.
Seoul Natl Univ, Sch Earth & Environm Sci, Seoul 151742, South Korea.
Univ Illinois, Dept Civil & Environm Engn, Urbana, IL 61801 USA.
SRI Int, Menlo Pk, CA 94025 USA.
Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA.
Kinki Univ, Fac Sci & Technol, Higashiosaka, Osaka 5778502, Japan.
Tokyo Univ Marine Sci & Technol, Fac Marine Engn, Koto Ku, Tokyo 1358533, Japan.
Univ Tokyo, Ctr Climate Syst Res, Meguro Ku, Tokyo 1538904, Japan.
Bay Area Environm Res Inst, Sonoma, CA 95476 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Natl Inst Environm Studies, Div Atmospher Environm, Tsukuba, Ibaraki, Japan.
Brookhaven Natl Lab, Div Atmospher Sci, Upton, NY 11973 USA.
RP Kahn, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM ralph.kahn@jpl.nasa.gov; janderson@asu.edu; tadand@atmos.washington.edu;
tim.bates@noaa.gov; fredb@bnl.gov; carrico@lamar.colostate.edu;
tclarke@soest.hawaii.edu; edutton@cmdl.noaa.gov; flagan@caltech.edu;
rfrouin@ucsd.edu; hajime@fksh.fc.u-tokai.ac.jp;
brent@aeronet.gsfc.nasa.gov; showell@soest.hawaii.edu;
huebert@hawaii.edu; anne.jefferson@noaa.gov; hjonsson@nps.navy.mil;
olga.v.kalashnikova@jpl.nasa.gov; jykim@metri.re.kr;
kimsw@air.snu.ac.kr; pinarkus@uiuc.edu; wli@sdsio-mail.jpl.nasa.gov;
jlivingston@mail.arc.nasa.gov; cameronm@soest.hawaii.edu;
jmerrill@boreas.gso.uri.edu; mukai@im.kindai.ac.jp;
murayama@ipc.tosho-u.ac.jp; teruyuki@ccsr.u-tokyo.ac.jp;
quinn@pmel.noaa.gov; redemann@atmos.ucla.edu; mrood@uiuc.edu;
philip.b.russell@nasa.gov; sano@im.kindai.ac.jp;
bschmid@mail.arc.nasa.gov; seinfeld@caltech.edu; nsugimot@nies.go.jp;
jian@bnl.gov; welton@virl.gsfc.nasa.gov; wonjg@air.snu.ac.kr;
yoon@snu.ac.kr
RI Welton, Ellsworth/A-8362-2012; Jefferson, Anne/K-4793-2012; Nakajima,
Teruyuki/H-2370-2013; Wang, Jian/G-9344-2011; Kahn, Ralph/D-5371-2012;
Sugimoto, Nobuo/C-5189-2015; Doherty, Sarah/D-5592-2015; Bates,
Timothy/L-6080-2016; Quinn, Patricia/R-1493-2016
OI Nakajima, Teruyuki/0000-0002-9042-504X; Kahn, Ralph/0000-0002-5234-6359;
Sugimoto, Nobuo/0000-0002-0545-1316; Doherty, Sarah/0000-0002-7796-6968;
Quinn, Patricia/0000-0003-0337-4895
NR 88
TC 23
Z9 23
U1 1
U2 7
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD OCT 5
PY 2004
VL 109
IS D19
AR D19S14
DI 10.1029/2003JD004339
PG 30
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 897XA
UT WOS:000227038200001
ER
PT J
AU Sarkisov, SS
Curley, MJ
Fields, A
Sarkisov, SS
Adamovsky, G
AF Sarkisov, SS
Curley, MJ
Fields, A
Sarkisov, SS
Adamovsky, G
TI Photomechanical effect in films of polyvinylidene fluoride
SO APPLIED PHYSICS LETTERS
LA English
DT Article
ID LIGHT
AB Photothermal bending of strips of polyvinylidene fluoride was initiated by a laser beam with a power of a few milliwatts. A bending strip generated a force of 10(-4) N that propelled a 1 g oscillating wheel of a mechanical clock. The frequency of photomechanical resonance at pulsed illumination was inversely proportional to the length of the strip. The proposed model explained bending as a result of uneven thermal expansion on opposite sides of the strip. The model predicted, in agreement with experiment, that the force is proportional to beam power and does not depend on the shape or position of the beam in the strip. (C) 2004 American Institute of Physics.
C1 Alabama A&M Univ, Dept Phys, Normal, AL 35762 USA.
Grissom High Sch, Huntsville, AL 35802 USA.
NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Alabama A&M Univ, Dept Phys, 4900 Meridian St, Normal, AL 35762 USA.
NR 9
TC 16
Z9 16
U1 0
U2 3
PU AMER INST PHYSICS
PI MELVILLE
PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA
SN 0003-6951
EI 1077-3118
J9 APPL PHYS LETT
JI Appl. Phys. Lett.
PD OCT 4
PY 2004
VL 85
IS 14
BP 2747
EP 2749
DI 10.1063/1.1802390
PG 3
WC Physics, Applied
SC Physics
GA 863FV
UT WOS:000224547300024
ER
PT J
AU Lane, MD
Dyar, MD
Bishop, JL
AF Lane, MD
Dyar, MD
Bishop, JL
TI Spectroscopic evidence for hydrous iron sulfate in the Martian soil
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID X-RAY SPECTROMETER; GUSEV CRATER; SPIRIT ROVER; MARS; MINERALS; ROCKS;
DUST
AB Despite in situ analyses by several landers, the composition of the Martian soil remains unclear. Recently, constituent minerals in the soil have been proposed from thermal emissivity and Mossbauer spectroscopic data from Mars. These data were interpreted to show spectral evidence for carbonate and an unspecified mineral containing bound water, as well as olivine. Here we present an alternative interpretation, suggesting that these spectral features can be satisfied by a single type of mineral, namely hydrous iron sulfates. Acidic waters necessary for production of hydrous iron sulfates would preclude carbonate formation and indicate a dramatically different chemical environment on Mars, in which olivine would be highly unstable and unlikely to survive soil formation, regardless of its presence in the rocks. Hydrous iron sulfates are efflorescent salts and may be crusting agents in the Martian soils.
C1 Planetary Sci Inst, Tucson, AZ 85719 USA.
Mt Holyoke Coll, Dept Earth & Envinrom, S Hadley, MA 01075 USA.
NASA, SETI Inst, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Planetary Sci Inst, 1700 E Ft Lowell Rd,Suite 106, Tucson, AZ 85719 USA.
EM lane@psi.edu
NR 32
TC 55
Z9 56
U1 0
U2 4
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 2
PY 2004
VL 31
IS 19
AR L19702
DI 10.1029/2004GL021231
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 861IA
UT WOS:000224408600004
ER
PT J
AU Whitley, KS
Gates, TS
AF Whitley, KS
Gates, TS
TI Thermal/mechanical response of a polymer matrix composite at cryogenic
temperatures
SO AIAA JOURNAL
LA English
DT Article; Proceedings Paper
CT AIAA/ASME/ASCE/AHS/ASC/SDM 43rd Structures, Structural Dynamics, and
Materials Conference
CY APR 22-25, 2002
CL DENVER, CO
SP AIAA, ASME, ASCE, AHS, ASC
ID FIBER REINFORCED-PLASTICS; THERMOPLASTIC MATRICES; LOADS
AB The mechanical behavior of a polymeric-matrix composite at cryogenic temperatures was investigated. Experimental data are presented on the residual mechanical properties of a carbon-fiber polymeric composite, IM7/PETI-5, both before and after aging. Both tension and compression modulus and strength were measured at room temperature, -196degreesC, and -269degreesC on five different laminate configurations consisting of [0](12) and [90](12) unidirectional laminates, [+/-25](3S) and [+/-45](3S) angle-ply laminates, and a 13-ply laminate [45/90/90/90/-45/0/0/0/-45/90/90/90/45]. One set of specimens was aged isothermally for 576 h at -184degreesC in an unconstrained state. Another set of corresponding specimens was aged under constant uniaxial strain for 576 hours at -184degreesC. Based on the experimental data presented, it is shown that trends in stiffness and strength that result from changes in temperature are not always smooth and consistent. Moreover, it is shown that loading mode and direction are significant for both stiffness and strength and that aging at cryogenic temperature while under load can alter the mechanical properties of pristine, unaged laminates made of IM7/PETI-5 material.
C1 NASA, Langley Res Ctr, Mech & Durabil Branch, Hampton, VA 23681 USA.
RP Whitley, KS (reprint author), NASA, Langley Res Ctr, Mech & Durabil Branch, Hampton, VA 23681 USA.
NR 17
TC 1
Z9 1
U1 1
U2 9
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0001-1452
J9 AIAA J
JI AIAA J.
PD OCT
PY 2004
VL 42
IS 10
BP 1991
EP 2001
DI 10.2514/1.1063
PG 11
WC Engineering, Aerospace
SC Engineering
GA 861NS
UT WOS:000224424200004
ER
PT J
AU Watson, WR
Jones, MG
Parrott, TL
Sobieski, J
AF Watson, WR
Jones, MG
Parrott, TL
Sobieski, J
TI Assessment of equation solvers and optimization techniques for
nonaxisymmetric liners
SO AIAA JOURNAL
LA English
DT Article
ID SOUND; FLOW
AB CPU times and memory requirements for a commonly used solver are compared to that of a state-of-the-art, parallel, sparse solver. The sparse solver is then used in conjunction with three optimization methodologies (genetic algorithm, contour deformation, and Davidon-Fletcher-Powell) to assess the usefulness of these methodologies for designing optimized nonaxisymmetric liners. This assessment is performed using a multimodal noise source in a finite length rectangular duct without flow. The sparse solver is found to reduce memory requirements by a factor of 5 and processing time by a factor of 11 when compared with the commonly used solver. All three optimization techniques give nearly the same optimum impedance for uniform liners, and this impedance approaches the Cremer optimum impedance at low frequency where only the plane wave mode is cuton. For nonaxisymmetric liners, the genetic algorithm gives improvements in optimum attenuation over the other optimization methodologies because of the presence of multiple local optima. Another important result is the discovery that, when optimized, a spanwise segmented liner with two segments gives attenuations equal to or substantially greater than an optimized axially segmented liner with the same number of segments.
C1 NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA.
NASA, Langley Res Ctr, Analyt & Computat Struct Branch, Hampton, VA 23681 USA.
RP Watson, WR (reprint author), NASA, Langley Res Ctr, Struct Acoust Branch, Mail Stop 463, Hampton, VA 23681 USA.
EM Willie.R.Watson@NASA.gov; Michael.G.Jones@NASA.gov;
Tony.L.Parrott@NASA.gov; Jaroslaw.Sobieski-1@NASA.gov
NR 26
TC 1
Z9 1
U1 0
U2 0
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0001-1452
J9 AIAA J
JI AIAA J.
PD OCT
PY 2004
VL 42
IS 10
BP 2010
EP 2018
DI 10.2514/1.9020
PG 9
WC Engineering, Aerospace
SC Engineering
GA 861NS
UT WOS:000224424200006
ER
PT J
AU Dorrington, AA
Jones, TW
Danehy, PM
Pappa, RS
AF Dorrington, AA
Jones, TW
Danehy, PM
Pappa, RS
TI Laser-induced-fluorescence photogrammetry for dynamic characterization
of membrane structures
SO AIAA JOURNAL
LA English
DT Article; Proceedings Paper
CT AIAA/ASME/SAE/ASEE 39th Joint Propulsion Conference
CY JUL 20, 2003
CL Huntsville, AL
SP AIAA, ASME, SAE, ASEE
AB Photogrammetry has proven to be a valuable tool for static and dynamic profiling of membrane-based inflatable and ultralightweight space structures. However, the traditional photogrammetric targeting techniques used for solid structures, such as attached retroreflective targets and white-light dot projection, have some disadvantages and are not ideally suited for measuring highly transparent or reflective membrane structures. In this paper, we describe a new laser-induced-fluorescence-based target generation technique that is more suitable for these types of structures. We also present several examples of noncontact noninvasive photogrammetric measurements of laser-dye doped polymer membranes, including the dynamic measurement and modal analysis of a 1 m x 1 m aluminized membrane.
C1 NASA, Langley Res Ctr, Adv Sensing & Opt Measurement Branch, Hampton, VA 23665 USA.
RP Dorrington, AA (reprint author), Univ Waikato, Dept Phys & Elect Engn, Private Bag 3105, Hamilton, New Zealand.
NR 10
TC 3
Z9 3
U1 0
U2 1
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0001-1452
J9 AIAA J
JI AIAA J.
PD OCT
PY 2004
VL 42
IS 10
BP 2124
EP 2129
DI 10.2514/1.5988
PG 6
WC Engineering, Aerospace
SC Engineering
GA 861NS
UT WOS:000224424200018
ER
PT J
AU Zwart, SR
Hargens, AR
Smith, SM
AF Zwart, SR
Hargens, AR
Smith, SM
TI The ratio of animal protein intake to potassium intake is a predictor of
bone resorption in space flight analogues and in ambulatory subjects
SO AMERICAN JOURNAL OF CLINICAL NUTRITION
LA English
DT Article
DE food intake; dietary protein; dietary potassium; bones; collagen
cross-links; bone markers; calcium; humans
ID NONCARBONIC ACID PRODUCTION; BED REST; MINERAL DENSITY; DIETARY-PROTEIN;
HIP FRACTURE; FRAMINGHAM OSTEOPOROSIS; POSTMENOPAUSAL WOMEN; CALCIUM
EXCRETION; BASE COMPOSITION; ELDERLY-WOMEN
AB Background: Bone loss is a critical concern for space travelers, and a dietary countermeasure would be of great benefit. Dietary protein and potassium-associated bicarbonate precursors may have opposing effects on the acid-base balance in the body and therefore on bone loss.
Objective: In 2 studies, we examined the ability of dietary protein and potassium to predict markers of bone metabolism.
Design: In the first study, 8 pairs of male identical twins were assigned to 1 of 2 groups: bed rest (sedentary, or SED, group) or bed rest with supine treadmill exercise in a lower-body negative pressure chamber (EX group). In a second study, groups of 4 subjects lived in a closed chamber for 60 or 91 d, and dietary data were collected for two or three 5-d sessions. Urinary calcium, N-telopeptide, and pyridinium cross-links were measured before bed rest; on bed rest days 5-6, 12-13, 19-20, and 26-27; and daily during the chamber studies. Data were analyzed by Pearson's correlation (P < 0.05).
Results: The ratio of animal protein intake to potassium intake was significantly correlated with N-telopeptide in the SED group during bed rest weeks 3 and 4 (r = 0.77 and 0.80) and during the 91-d chamber study (r = 0.75). The ratio of animal protein intake to potassium intake was positively correlated with pyridinium crosslinks before bed rest in the EX group (r = 0.83), in the EX group during bed rest week 1 (r = 0.84), and in the SED group during bed rest week 2 (r = 0.72) but not during either chamber study. In both studies, these relations were not significant with the ratio of vegetable protein intake to potassium intake.
Conclusions: The ratio of animal protein intake to potassium intake may affect bone in ambulatory and bed-rest subjects. Changing this ratio may help to prevent bone loss on Earth and during space flight.
C1 NASA, Lyndon B Johnson Space Ctr, Nutrit Biochem Lab, Human Adaptat & Countermeasures Off, Houston, TX 77058 USA.
Univ Calif San Diego, Dept Orthopaed Surg, Med Ctr, San Diego, CA 92103 USA.
RP Smith, SM (reprint author), NASA, Lyndon B Johnson Space Ctr, Nutrit Biochem Lab, Human Adaptat & Countermeasures Off, Mail Code SK3, Houston, TX 77058 USA.
EM scott.m.smith@nasa.gov
FU NCRR NIH HHS [M01-RR00827]
NR 50
TC 26
Z9 28
U1 1
U2 6
PU AMER SOC NUTRITION-ASN
PI BETHESDA
PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA
SN 0002-9165
J9 AM J CLIN NUTR
JI Am. J. Clin. Nutr.
PD OCT
PY 2004
VL 80
IS 4
BP 1058
EP 1065
PG 8
WC Nutrition & Dietetics
SC Nutrition & Dietetics
GA 856VI
UT WOS:000224073000039
PM 15447920
ER
PT J
AU Zlochin, M
Birattari, M
Meuleau, N
Dorigo, M
AF Zlochin, M
Birattari, M
Meuleau, N
Dorigo, M
TI Model-based search for combinatorial optimization: A critical survey
SO ANNALS OF OPERATIONS RESEARCH
LA English
DT Article
DE ant colony optimization; cross-entropy method; stochastic gradient
ascent; estimation of distribution algorithms; adaptive optimization;
metaheuristics
ID ANT COLONY OPTIMIZATION; SYSTEM
AB In this paper we introduce model-based search as a unifying framework accommodating some recently proposed metaheuristics for combinatorial optimization such as ant colony optimization, stochastic gradient ascent, cross-entropy and estimation of distribution methods. We discuss similarities as well as distinctive features of each method and we propose some extensions.
C1 Weizmann Inst Sci, Dept Appl Math & Comp Sci, IL-76100 Rehovot, Israel.
Free Univ Brussels, IRIDIA, Brussels, Belgium.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Tech Univ Darmstadt, Intellektik, D-64287 Darmstadt, Germany.
RP Weizmann Inst Sci, Dept Appl Math & Comp Sci, IL-76100 Rehovot, Israel.
EM zmark@weizmann.ac.il; mbiro@ulb.ac.be; nmeuleau@email.arc.nasa.gov;
mdorigo@ulb.ac.be
RI Dorigo, Marco/B-5664-2013; Birattari, Mauro/D-2597-2009
OI Dorigo, Marco/0000-0002-3971-0507; Birattari, Mauro/0000-0003-3309-2194
NR 44
TC 96
Z9 101
U1 0
U2 11
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0254-5330
EI 1572-9338
J9 ANN OPER RES
JI Ann. Oper. Res.
PD OCT
PY 2004
VL 131
IS 1-4
BP 373
EP 395
DI 10.1023/B:ANOR.0000039526.52305.af
PG 23
WC Operations Research & Management Science
SC Operations Research & Management Science
GA 849JP
UT WOS:000223535200017
ER
PT J
AU Glavin, DP
Cleaves, HJ
Schubert, M
Aubrey, A
Bada, JL
AF Glavin, DP
Cleaves, HJ
Schubert, M
Aubrey, A
Bada, JL
TI New method for estimating bacterial cell abundances in natural samples
by use of sublimation
SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY
LA English
DT Article
ID MARINE-BACTERIA; SEDIMENTS; SEA; ENUMERATION; DIVERSITY; SEAWATER;
VIRUSES; ACIDS; MARS
AB We have developed a new method based on the sublimation of adenine from Escherichia coli to estimate bacterial cell counts in natural samples. To demonstrate this technique, several types of natural samples, including beach sand, seawater, deep-sea sediment, and two soil samples from the Atacama Desert, were heated to a temperature of 500degreesC for several seconds under reduced pressure. The sublimate was collected on a cold finger, and the amount of adenine released from the samples was then determined by high-performance liquid chromatography with UV absorbance detection. Based on the total amount of adenine recovered from DNA and RNA in these samples, we estimated bacterial cell counts ranging from similar to10(5) to 10(9) E. coli cell equivalents per gram. For most of these samples, the sublimation-based cell counts were in agreement with total bacterial counts obtained by traditional DA-PI (4,6-diamidino-2-phenylindole) staining.
C1 NASA, Goddard Space Flight Ctr, Atmospher Expt Branch, Greenbelt, MD 20771 USA.
Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA.
ENS Lyon, LBMC, CNRS, UMR5161, Lyon, France.
RP Glavin, DP (reprint author), NASA, Goddard Space Flight Ctr, Atmospher Expt Branch, Code 915, Greenbelt, MD 20771 USA.
EM daniel.p.glavin@nasa.gov
RI Glavin, Daniel/D-6194-2012;
OI Glavin, Daniel/0000-0001-7779-7765; Cleaves,
Henderson/0000-0003-4101-0654
NR 25
TC 30
Z9 31
U1 2
U2 16
PU AMER SOC MICROBIOLOGY
PI WASHINGTON
PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA
SN 0099-2240
J9 APPL ENVIRON MICROB
JI Appl. Environ. Microbiol.
PD OCT
PY 2004
VL 70
IS 10
BP 5923
EP 5928
DI 10.1128/AEM.70.10.5923-5928.2004
PG 6
WC Biotechnology & Applied Microbiology; Microbiology
SC Biotechnology & Applied Microbiology; Microbiology
GA 860PT
UT WOS:000224356200029
PM 15466534
ER
PT J
AU Steffen, AT
Barger, AJ
Capak, P
Cowie, LL
Mushotzky, RF
Yang, Y
AF Steffen, AT
Barger, AJ
Capak, P
Cowie, LL
Mushotzky, RF
Yang, Y
TI An optical catalog of the Chandra Large Area Synoptic X-ray Survey
sources
SO ASTRONOMICAL JOURNAL
LA English
DT Article
DE X-rays : galaxies; X-rays : general
ID DEEP-FIELD-NORTH; GALAXY REDSHIFT SURVEY; LARGE-SCALE STRUCTURE; LOCKMAN
HOLE; STARBURST GALAXIES; ENERGY-DISTRIBUTIONS; HELLAS2XMM SURVEY;
LARGE-SAMPLE; SOUTH; ASCA
AB We present photometric and spectroscopic observations of the X-ray sources detected in the wide-area, moderately deep Chandra Large Area Synoptic X-ray Survey (CLASXS) of the Lockman Hole-Northwest field. We have B, V, R, I, and z' photometry for 521 (99%) of the 525 sources in the X-ray catalog and spectroscopic redshifts for 271 (52%), including 20 stars. We do not find evidence for redshift groupings of the X-ray sources, like those found in the Chandra Deep Field surveys, because of the larger solid angle covered by this survey. We separate the X-ray sources by optical spectral type and examine the colors, apparent and absolute magnitudes, and redshift distributions for the broad-line and non-broad-line active galactic nuclei. Combining our wide-area survey with other Chandra and XMM-Newton hard X-ray surveys, we find a definite lack of luminous, high accretion rate sources at z < 1, consistent with previous observations that showed that supermassive black hole growth is dominated at low redshifts by sources with low accretion rates.
C1 Univ Wisconsin, Dept Astron, Madison, WI 53706 USA.
Univ Hawaii, Dept Phys & Astron, Honolulu, HI 96822 USA.
Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA.
Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
RP Steffen, AT (reprint author), Univ Wisconsin, Dept Astron, 475 N Charter St, Madison, WI 53706 USA.
NR 55
TC 47
Z9 47
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-6256
J9 ASTRON J
JI Astron. J.
PD OCT
PY 2004
VL 128
IS 4
BP 1483
EP 1500
DI 10.1086/423998
PG 18
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YD
UT WOS:000224303400001
ER
PT J
AU Yang, Y
Mushotzky, RF
Steffen, AT
Barger, AJ
Cowie, LL
AF Yang, Y
Mushotzky, RF
Steffen, AT
Barger, AJ
Cowie, LL
TI The Chandra Large Area Synoptic X-ray Survey (CLASXS) of the Lockman
Hole-Northwest: The X-ray catalog
SO ASTRONOMICAL JOURNAL
LA English
DT Article
DE cosmology : observations; galaxies : active; X-rays : diffuse background
ID ROSAT DEEP SURVEY; OPTICAL-IDENTIFICATION; SENSITIVITY SURVEY; GALAXY
CLUSTERS; SOURCE COUNTS; FIELD-SOUTH; XMM-NEWTON; ASCA; SKY; REDSHIFTS
AB We present the X-ray catalog and basic results from our Chandra Large Area Synoptic X-ray Survey (CLASXS) of the Lockman Hole-Northwest field. Our nine ACIS-I fields cover a contiguous solid angle of similar to0.4 deg(2) and reach fluxes of 5 x 10(-16) ergs cm(-2) s(-1) (0.4-2 keV) and 3 x 10(-15) ergs cm(-2) s(-1) (2-8 keV). Our survey bridges the gap between ultradeep pencil-beam surveys, such as the Chandra Deep Fields (CDFs), and shallower, large-area surveys, allowing a better probe of the X-ray sources that contribute most of the 2-10 keV cosmic X-ray background (CXB). We find a total of 525 X-ray point sources and four extended sources. At similar to10(-1)4 ergs cm(-2) s(-1) (2-8 keV), our number counts are significantly higher than those of several noncontiguous, large-area surveys. Such a large difference is an indication of clustering in the X-ray sources. On the other hand, the integrated flux from the CLASXS field, combined with ASCA and Chandra ultradeep surveys, is consistent with results from other large-area surveys, within the variance of the CXB. We see spectral evolution in the hardening of the sources at fluxes below 10(-1)4 ergs cm(-2) s(-1), which agrees with previous observations from Chandra and XMM-Newton. About one third of the sources in the CLASXS field have multiple observations, which allow variability tests. Above 4 x 10(-14) ergs cm(-2) s(-1) (0.4-8 keV), similar to60% of the sources are variable. We also investigated the spectral variability of the variable sources. While most show spectral softening with increasing flux, or no significant spectral change, there are a few sources that show a different trend. We observed four extended sources in CLASXS, which is consistent with the previously measured log N-log S relation for galaxy clusters. Using X-ray spectra and optical colors, we argue that three of the four extended sources are galaxy clusters or galaxy groups. We report the discovery of a gravitational lensing arc associated with one of these sources. Using red-sequence and brightest cluster galaxy methods, we find that the redshifts of the extended sources are in the range z similar to 0.5-1. The inferred masses within the Einstein radii are consistent with the mass profiles of local groups scaled to the same virial radii.
C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
Univ Wisconsin, Dept Astron, Madison, WI 53706 USA.
Univ Hawaii, Dept Phys & Astron, Honolulu, HI 96822 USA.
Univ Hawaii, Astron Inst, Honolulu, HI 96822 USA.
RP Yang, Y (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
NR 41
TC 44
Z9 44
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-6256
J9 ASTRON J
JI Astron. J.
PD OCT
PY 2004
VL 128
IS 4
BP 1501
EP 1523
DI 10.1086/423996
PG 23
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YD
UT WOS:000224303400002
ER
PT J
AU Mieske, S
Infante, L
Benitez, N
Coe, D
Blakeslee, JP
Zekser, K
Ford, HC
Broadhurst, TJ
Illingworth, GD
Hartig, GF
Clampin, M
Ardila, DR
Bartko, F
Bouwens, RJ
Brown, RA
Burrows, CJ
Cheng, ES
Cross, NJG
Feldman, PD
Franx, M
Golimowski, DA
Goto, T
Gronwall, C
Holden, B
Homeier, N
Kimble, RA
Krist, JE
Lesser, MP
Martel, AR
Menanteau, F
Meurer, GR
Miley, GK
Postman, M
Rosati, P
Sirianni, M
Sparks, WB
Tran, HD
Tsvetanov, ZI
White, RL
Zheng, W
AF Mieske, S
Infante, L
Benitez, N
Coe, D
Blakeslee, JP
Zekser, K
Ford, HC
Broadhurst, TJ
Illingworth, GD
Hartig, GF
Clampin, M
Ardila, DR
Bartko, F
Bouwens, RJ
Brown, RA
Burrows, CJ
Cheng, ES
Cross, NJG
Feldman, PD
Franx, M
Golimowski, DA
Goto, T
Gronwall, C
Holden, B
Homeier, N
Kimble, RA
Krist, JE
Lesser, MP
Martel, AR
Menanteau, F
Meurer, GR
Miley, GK
Postman, M
Rosati, P
Sirianni, M
Sparks, WB
Tran, HD
Tsvetanov, ZI
White, RL
Zheng, W
TI Ultracompact dwarf galaxies in Abell 1689: A photometric study with the
advanced camera for surveys
SO ASTRONOMICAL JOURNAL
LA English
DT Article
DE galaxies : clusters : individual (Abell 1689); galaxies : dwarf;
galaxies : fundamental parameters; galaxies : nuclei; globular clusters
: general
ID GLOBULAR-CLUSTER SYSTEMS; FORNAX CLUSTER; LUMINOSITY FUNCTION; A1689;
MASS; INSIGHTS; MODELS; HST
AB The properties of ultracompact dwarf (UCD) galaxy candidates in Abell 1689 (z = 0.183) are investigated, based on deep high-resolution images from the Hubble Space Telescope Advanced Camera for Surveys. A UCD candidate has to be unresolved, have i < 28 mag (M-V < -11.5 mag), and satisfy color limits derived from Bayesian photometric redshifts. We find 160 UCD candidates with 22 mag < i < 28 mag. We estimate that about 100 of these are cluster members, based on their spatial distribution and photometric redshifts. For i greater than or similar to 26.8 mag, the radial and luminosity distribution of the UCD candidates can be explained well by Abell 1689's globular cluster ( GC) system. For i less than or similar to 26.8 mag, there is an overpopulation of 15 +/- 5 UCD candidates with respect to the GC luminosity function. For i less than or similar to 26 mag, the radial distribution of UCD candidates is more consistent with the dwarf galaxy population than with the GC system of Abell 1689. The UCD candidates follow a color-magnitude trend with a slope similar to that of Abell 1689's genuine dwarf galaxy population, but shifted fainter by about 2-3 mag. Two of the three brightest UCD candidates (M-V similar or equal to -17 mag) are slightly resolved. At the distance of Abell 1689, these two objects would have King profile core radii of similar or equal to35 pc and r(eff) similar or equal to 300 pc, implying luminosities and sizes 2-3 times those of M32's bulge. Additional photometric redshifts obtained with late-type stellar and elliptical galaxy templates support the assignment of these two resolved sources to Abell 1689 but also allow for up to four foreground stars among the six brightest UCD candidates. Our findings imply that in Abell 1689 there are greater than or equal to10 UCDs with M-V < -12.7 mag, probably created by stripping "normal" dwarf or spiral galaxies. Compared with the UCDs in the Fornax Cluster - the location of their original discovery - they are brighter, larger, and have colors closer to normal dwarf galaxies. This suggests that they may be in an intermediate stage of the stripping process. Checking the photometric redshifts of the brightest UCD candidates with spectroscopy would be the next step to definitely confirm the existence of UCDs in Abell 1689.
C1 Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile.
Univ Bonn, Sternwarte, D-53121 Bonn, Germany.
Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA.
Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel.
Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA.
Space Telescope Sci Inst, Baltimore, MD 21218 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Bartko Sci & Technol, Brighton, CO 80602 USA.
Conceptual Analyt LLC, Glenn Dale, MD 20769 USA.
Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands.
Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA.
Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
European So Observ, D-85748 Garching, Germany.
European Space Agcy, Res & Sci Support Dept, F-75738 Paris 15, France.
WM Keck Observ, Kamuela, HI 96743 USA.
RP Mieske, S (reprint author), Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Casilla 306, Santiago 22, Chile.
EM smieske@astro.uni-bonn.de; linfante@astro.puc.cl
RI White, Richard/A-8143-2012; Clampin, mark/D-2738-2012; Kimble,
Randy/D-5317-2012;
OI tran, hien/0000-0001-7548-6664; Benitez, Narciso/0000-0002-0403-7455;
Blakeslee, John/0000-0002-5213-3548
NR 44
TC 37
Z9 37
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-6256
J9 ASTRON J
JI Astron. J.
PD OCT
PY 2004
VL 128
IS 4
BP 1529
EP 1540
DI 10.1086/423701
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YD
UT WOS:000224303400004
ER
PT J
AU Golimowski, DA
Henry, TJ
Krist, JE
Dieterich, S
Ford, HC
Illingworth, GD
Ardila, DR
Clampin, M
Franz, OG
Wasserman, LH
Benedict, GF
McArthur, BE
Nelan, EG
AF Golimowski, DA
Henry, TJ
Krist, JE
Dieterich, S
Ford, HC
Illingworth, GD
Ardila, DR
Clampin, M
Franz, OG
Wasserman, LH
Benedict, GF
McArthur, BE
Nelan, EG
TI The solar neighborhood. IX. Hubble Space Telescope detections of
companions to five M and L dwarfs within 10 parsecs of the sun
SO ASTRONOMICAL JOURNAL
LA English
DT Article
DE binaries : close; stars : individual (G239-25AB, GJ 1001ABC, GJ 54AB, GJ
84AB, LHS 224AB); stars : low-mass, brown dwarfs
ID LOW-MASS STARS; PROPER MOTION STARS; EXTRASOLAR GIANT PLANETS;
TO-INFRARED PHOTOMETRY; FINE GUIDANCE SENSORS; ALL-SKY SURVEY; BROWN
DWARFS; NEARBY STARS; SPECTROSCOPIC SURVEY; EVOLUTIONARY MODELS
AB We report the detections of low-mass companions to five M and L dwarfs within 10 pc of the Sun using the Hubble Space Telescope (HST) Near-Infrared Camera and Multi-Object Spectrometer (NICMOS). Follow-up observations using the HST Advanced Camera for Surveys (ACS) and Fine Guidance Sensor 1r (FGS1r) confirm our NICMOS discoveries of companions to the L4.5 dwarf GJ 1001B (LHS 102B) and the M5 dwarf LHS 224, respectively. Images obtained with the Astrophysical Research Consortium 3.5 m telescope at Apache Point Observatory verify our discovery of a companion to the M3 dwarf G239-25. Our NICMOS images confirm the previously suspected duplicity of the M3 dwarfs GJ 54 and GJ 84. The components of GJ 1001BC and LHS 224AB have nearly equal luminosities in all the ACS and/or NICMOS bandpasses in which they were observed. The magnitudes of GJ 54A and B in one FGS1r bandpass and four NICMOS bandpasses differ by less than or similar to1. GJ 84B and G239-25B are similar to4 mag fainter than their M3 companions in the NICMOS bandpasses. We estimate from our NICMOS photometry that GJ 84B and G239-25B have spectral types M7 and M8, respectively, and masses near the lower limit for sustained hydrogen burning. The apparent separations of GJ 1001BC, GJ 54AB, and LHS 224AB suggest orbital periods less than 5 yr. These binary dwarfs are ideal candidates for continued astrometric monitoring that will quickly yield accurate dynamic masses needed to constrain the mass-luminosity relation for low-mass stars and brown dwarfs.
C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA.
Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA.
Space Telescope Sci Inst, Baltimore, MD 21218 USA.
Univ Calif Santa Cruz, Lick Observ, Santa Cruz, CA 95064 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Lowell Observ, Flagstaff, AZ 86001 USA.
Univ Texas, McDonald Observ, Austin, TX 78712 USA.
RP Golimowski, DA (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA.
RI Clampin, mark/D-2738-2012
NR 86
TC 62
Z9 62
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-6256
EI 1538-3881
J9 ASTRON J
JI Astron. J.
PD OCT
PY 2004
VL 128
IS 4
BP 1733
EP 1747
DI 10.1086/423911
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YD
UT WOS:000224303400022
ER
PT J
AU Perrin, G
Ridgway, ST
Mennesson, B
Cotton, WD
Woillez, J
Verhoelst, T
Schuller, P
du Foresto, VC
Traub, WA
Millan-Gabet, R
Lacasse, MG
AF Perrin, G
Ridgway, ST
Mennesson, B
Cotton, WD
Woillez, J
Verhoelst, T
Schuller, P
du Foresto, VC
Traub, WA
Millan-Gabet, R
Lacasse, MG
TI Unveiling Mira stars behind the molecules - Confirmation of the
molecular layer model with narrow band near-infrared interferometry
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE techniques : interferometric; stars : AGB and post-AGB; stars :
fundamental parameters; stars : mass-loss; infrared : stars
ID LONG-PERIOD VARIABLES; BISPECTRUM SPECKLE INTERFEROMETRY; SPECTRAL
IRRADIANCE CALIBRATION; ASYMPTOTIC GIANT BRANCH; R-LEONIS; O-CETI;
EFFECTIVE TEMPERATURES; IOTA INTERFEROMETER; DUST SHELL; PULSATION
AB We have observed Mira stars with the FLUOR beamcombiner on the IOTA interferometer in narrow bands around 2.2 mum wavelength. We find systematically larger diameters in bands contaminated by water vapor and CO. The visibility measurements can be interpreted with a model comprising a photosphere surrounded by a thin spherical molecular layer. The high quality of the fits we obtain demonstrates that this simple model accounts for most of the star's spatial structure. For each star and each period we were able to derive the radius and temperature of the star and of the molecular layer as well as the optical depth of the layer in absorption and continuum bands. The typical radius of the molecular layer is 2.2 R-star with a temperature ranging between 1500 and 2100 K. The photospheric temperatures we find are in agreement with spectral types of Mira stars. Our photospheric diameters are found smaller than in previous studies by several tens of percent. We believe previous diameters were biased by the use of unsuited geometrical models to explain visibilities. The conclusions of this work are various. First, we offer a consistent view of Mira stars over a wide range of wavelengths. Second, the parameters of the molecular layer we find are consistent with spectroscopic studies. Third, from our diameter measurements we deduce that all Mira stars are fundamental mode pulsators and that previous studies leading to the conclusion of the first-overtone mode were biased by too large diameter estimates.
C1 Observ Paris, LESIA, UMR 8109, F-92190 Meudon, France.
Natl Opt Astron Observ, Tucson, AZ 85726 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Natl Radio Astron Observ, Charlottesville, VA 22903 USA.
Keck Observ, Kamuela, HI 96743 USA.
Sterrenkunde Leuven, Louvain, Belgium.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA.
RP Perrin, G (reprint author), Observ Paris, LESIA, UMR 8109, F-92190 Meudon, France.
EM guy.perrin@obspm.fr
NR 57
TC 93
Z9 93
U1 0
U2 0
PU E D P SCIENCES
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2004
VL 426
IS 1
BP 279
EP U123
DI 10.1051/0004-6361:20041098
PG 21
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 869ED
UT WOS:000224965300032
ER
PT J
AU Di Cocco, G
Foschini, L
Grandi, P
Malaguti, G
Castro-Tirado, AJ
Chaty, S
Dean, AJ
Grenier, I
Hermsen, W
Kuiper, L
Lund, N
Mirabel, F
AF Di Cocco, G
Foschini, L
Grandi, P
Malaguti, G
Castro-Tirado, AJ
Chaty, S
Dean, AJ
Grenier, I
Hermsen, W
Kuiper, L
Lund, N
Mirabel, F
TI INTEGRAL observation of 3EG J1736-2908
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE gamina-rays : observations; X-rays : galaxies; galaxies : active;
galaxies : individual : GRS 1734-292
ID GAMMA-RAY SOURCES; GALACTIC-CENTER REGION; RADIO GALAXY NGC-6251;
VARIABILITY; DISCOVERY; CATALOG; IMAGER
AB The possible identification by INTEGRAL of the EGRET source 3EG J1736-2908 with the active galactic nucleus GRS 1734-292 is discussed. The latter was discovered in 1990 and later identified with a Seyfert 1 galaxy. At the time of the compilation of the 3rd EGRET Catalog, it was not considered as a possible counterpart of the source 3EG J1736-2908, which remained unidentified. A detailed multiwavelength study of the EGRET error circle is presented, by including archival radio, soft- and hard-X observations, suggesting that GRS 1734-292 could be a likely counterpart of 3EG J1736-2908, even though this poses very interesting questions about the production mechanisms of gamma-rays with energies greater than 100 MeV.
C1 CNR, Ist Astrofis Spaziale & Fis Cosm, Sez Bologna, I-40129 Bologna, Italy.
CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain.
CEA Saclay, CNRS, FRE 2591, DSM,DAPNIA,SAp, F-91191 Gif Sur Yvette, France.
Univ Paris 07, F-75251 Paris 05, France.
Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England.
NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
SRON, Natl Inst Space Res, NL-3584 CA Utrecht, Netherlands.
Danish Space Res Inst, DK-2100 Copenhagen, Denmark.
RP Di Cocco, G (reprint author), CNR, Ist Astrofis Spaziale & Fis Cosm, Sez Bologna, Via Gobetti 101, I-40129 Bologna, Italy.
EM dicocco@bo.iasf.cnr.it
RI Foschini, Luigi/H-3833-2012;
OI Foschini, Luigi/0000-0001-8678-0324; Malaguti,
Giuseppe/0000-0001-9872-3378; Grandi, Paola/0000-0003-1848-6013;
Castro-Tirado, A. J./0000-0003-2999-3563; Chaty,
Sylvain/0000-0002-5769-8601
NR 40
TC 6
Z9 6
U1 0
U2 0
PU E D P SCIENCES
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2004
VL 425
IS 1
BP 89
EP 93
DI 10.1051/0004-6361:20040484
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865WH
UT WOS:000224734400013
ER
PT J
AU Hyung, S
Pottasch, SR
Feibelman, WA
AF Hyung, S
Pottasch, SR
Feibelman, WA
TI Photoionization model analysis of the planetary nebula Hu1-2
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE ISM : abundances; ISM : planetary nebulae : individual : Hu 1-2
ID CHEMICAL-COMPOSITION; ATMOSPHERES; ABUNDANCES; DISTANCES; EVOLUTION;
SAMPLE; STARS; MASS
AB We have obtained high resolution optical spectra of the planetary nebula Hu 1-2 in the wavelength region of 3700 Angstrom-10050 Angstrom, with the Hamilton Echelle Spectrograph (HES) at Lick Observatory. Diagnostic analysis indicates that the nebular gas can be represented by inhomogeneous shells of electron density N(epsilon)similar or equal to4000-10000 cm(-3), and a gas temperature of 12000-18000 K. Using the spherically symmetric photoionization model with appropriate abundances, we tried to accommodate the observed physical conditions and high electron temperatures. The chemical composition of the nebula was derived from calculations using a photoionization model which predicts the observed IUE, HES and ISO line intensities; and the composition was then compared to previous determinations. Model analysis confirms the semi-empirically determined abundance derivations carried out in earlier studies. He and N abundances are high, but those of C, O, Ne and S are very low.
C1 Chungbuk Natl Univ, Sch Sci Educ Astron, CheongJu, ChongBuk, South Korea.
Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands.
NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA.
RP Hyung, S (reprint author), Chungbuk Natl Univ, Sch Sci Educ Astron, 48 Gaeshin Dong, CheongJu, ChongBuk, South Korea.
EM hyung@chungbuk.ac.kr
NR 20
TC 5
Z9 5
U1 0
U2 0
PU E D P SCIENCES
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2004
VL 425
IS 1
BP 143
EP 149
DI 10.1051/0004-6361:20041005
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865WH
UT WOS:000224734400019
ER
PT J
AU Ivarsson, S
Wahgren, GM
Dai, Z
Lundberg, H
Leckrone, DS
AF Ivarsson, S
Wahgren, GM
Dai, Z
Lundberg, H
Leckrone, DS
TI Constraining the very heavy elemental abundance peak in the chemically
peculiar star chi Lupi, with new atomic data for Os II and Ir II
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE atomic data; stars : abundances; stars : chemically peculiar; stars :
individual : chi Lupi
ID HGMN STARS
AB The determination of elemental abundances plays an important role in understanding the atmospheric processes that lead to anomalies in spectra of chemically peculiar stars. Ongoing study of the HgMn star chi Lupi has defined Much of the elemental abundance distribution but progress is dependent upon the availability and accuracy of the atomic data. Here we present experimentally determined wavelengths and oscillator strengths for 27 Os II and 23 Ir II transitions. The oscillator strengths have been determined by combining radiative lifetimes measured using the laser-induced fluorescence technique with branching fractions determined from Fourier transform spectrometer emission line intensities. The new data were used in a synthetic spectrum analysis of high-resolution ultraviolet spectra of chi Lupi obtained with the Hubble Space Telescope. Weak abundance enhancements were determined for both elements, [Os/H] = +1.3 dex and [Ir/H] = +0.7 dex, which now clearly defines the heavy element abundance peak in this star to be comprised of only the four elements Pt, An, Hg, and Tl. This result offers a new constraint on theoretical efforts to explain the observed spectrum anomalies.
C1 Lund Univ, Lund Observ, S-22100 Lund, Sweden.
Lund Inst Technol, Dept Phys, S-22100 Lund, Sweden.
NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Ivarsson, S (reprint author), Lund Univ, Lund Observ, POB 43, S-22100 Lund, Sweden.
EM stefan.ivarsson@astro.lu.se
NR 24
TC 14
Z9 14
U1 0
U2 1
PU E D P SCIENCES
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2004
VL 425
IS 1
BP 353
EP 360
DI 10.1051/0004-6361:20040298
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 865WH
UT WOS:000224734400040
ER
PT J
AU Watson, D
Hjorth, J
Jakobsson, P
Pedersen, K
Patel, S
Kouveliotou, C
AF Watson, D
Hjorth, J
Jakobsson, P
Pedersen, K
Patel, S
Kouveliotou, C
TI Massive star-formation rates of gamma-ray burst host galaxies: An
unobscured view in X-rays
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE gamma rays : bursts; X-rays : galaxies; X-rays : binaries; galaxies :
starburst
ID HUBBLE-SPACE-TELESCOPE; SCUBA SUBMILLIMETER OBSERVATIONS; FORMATION RATE
INDICATOR; 2-10 KEV LUMINOSITY; SUPERNOVA 2003DH; GRB 970508; AFTERGLOW;
SPECTROSCOPY; GRB-000926; GRB-010222
AB The hard X-ray (2-10 keV) luminosity of a star-forming galaxy tracks its population of high mass X-ray binaries and is essentially unobscured. It is therefore a practically unbiased measure of star-formation in the host galaxies of gamma-ray bursts (GRBs). Using recent and archival observations of GRBs with the XMM-Newton and Chandra X-ray observatories, limits are placed on the underlying X-ray emission from GRB hosts. Useful limits on the current massive star-formation rates (SFRs), unaffected by obscuration, are obtained for the hosts of three low redshift GRBs: GRB 980425, GRB 030329 and GRB 031203. These limits show that though the specific SFRs may be high (as in dwarf starburst galaxies), none have massive obscured star-formation at the levels implied by the sub-mm detection of some GRB hosts. It is also shown that in cases where the faint luminosities of the late time afterglow or supernova emission are of interest, the contribution of the host galaxy to the X-ray flux may be significant.
C1 Univ Copenhagen, Niels Bohr Inst, Astron Observ, DK-2100 Copenhagen O, Denmark.
USRA, NSSTC, Huntsville, AL 35805 USA.
NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35812 USA.
RP Watson, D (reprint author), Univ Copenhagen, Niels Bohr Inst, Astron Observ, Juliane Maries Vej 30, DK-2100 Copenhagen O, Denmark.
EM darach@astro.ku.dk
RI Hjorth, Jens/M-5787-2014; Watson, Darach/E-4521-2015; Jakobsson,
Pall/L-9950-2015
OI Hjorth, Jens/0000-0002-4571-2306; Watson, Darach/0000-0002-4465-8264;
Jakobsson, Pall/0000-0002-9404-5650
NR 73
TC 11
Z9 11
U1 0
U2 0
PU E D P SCIENCES
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD OCT
PY 2004
VL 425
IS 2
BP L33
EP L36
DI 10.1051/0004-6361:200400058
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 862YD
UT WOS:000224526500004
ER
PT J
AU Falcone, AD
Bond, IH
Boyle, PJ
Bradbury, SM
Buckley, JH
Carter-Lewis, D
Celik, O
Cui, W
Daniel, M
D'Vali, M
Perez, ID
Duke, C
Fegan, DJ
Fegan, SJ
Finley, JP
Fortson, LF
Gaidos, J
Gammell, S
Gibbs, K
Gillanders, GH
Grube, J
Hall, J
Hall, TA
Hanna, D
Hillas, AM
Holder, J
Horan, D
Jarvis, A
Kenny, GE
Kertzman, M
Kieda, D
Kildea, J
Knapp, J
Kosack, K
Krawczynski, H
Krennrich, F
Lang, MJ
LeBohec, S
Linton, E
Lloyd-Evans, J
Milovanovic, A
Moriarty, P
Muller, D
Nagai, T
Nolan, S
Ong, R
Pallassini, R
Petry, D
Pizlo, F
Power-Mooney, B
Quinn, J
Quinn, M
Ragan, K
Rebillot, P
Reynolds, PT
Rose, HJ
Schroedter, M
Sembroski, G
Swordy, SP
Syson, A
Tyler, K
Vassiliev, VV
Wakely, SP
Walker, G
Weekes, TC
Zweerink, J
AF Falcone, AD
Bond, IH
Boyle, PJ
Bradbury, SM
Buckley, JH
Carter-Lewis, D
Celik, O
Cui, W
Daniel, M
D'Vali, M
Perez, ID
Duke, C
Fegan, DJ
Fegan, SJ
Finley, JP
Fortson, LF
Gaidos, J
Gammell, S
Gibbs, K
Gillanders, GH
Grube, J
Hall, J
Hall, TA
Hanna, D
Hillas, AM
Holder, J
Horan, D
Jarvis, A
Kenny, GE
Kertzman, M
Kieda, D
Kildea, J
Knapp, J
Kosack, K
Krawczynski, H
Krennrich, F
Lang, MJ
LeBohec, S
Linton, E
Lloyd-Evans, J
Milovanovic, A
Moriarty, P
Muller, D
Nagai, T
Nolan, S
Ong, R
Pallassini, R
Petry, D
Pizlo, F
Power-Mooney, B
Quinn, J
Quinn, M
Ragan, K
Rebillot, P
Reynolds, PT
Rose, HJ
Schroedter, M
Sembroski, G
Swordy, SP
Syson, A
Tyler, K
Vassiliev, VV
Wakely, SP
Walker, G
Weekes, TC
Zweerink, J
TI A search for TeV gamma-ray emission from high-peaked flat-spectrum radio
quasars using the Whipple air Cerenkov telescope
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE galaxies : active; gamma rays : observations; quasars : general
ID BL-LACERTAE OBJECTS; BLAZAR SURVEY; LAC OBJECTS; RADIATION;
IDENTIFICATIONS; ABSORPTION; SEQUENCE; ENERGIES; PROJECT; SYSTEM
AB Blazars have traditionally been separated into two broad categories based on their optical emission characteristics. Blazars with faint or no emission lines are referred to as BL Lacertae objects ( BL Lacs), and blazars with prominent, broad emission lines are commonly referred to as flat-spectrum radio quasars (FSRQs). The spectral energy distribution of FSRQs has generally been thought of as being more akin to the low-peaked BL Lacs, which exhibit a peak in the infrared region of the spectrum, as opposed to high-peaked BL Lacs (HBLs), which exhibit a peak in UV/X-ray region of the spectrum. All blazars that are currently confirmed as sources of TeV emission fall into the HBL category. Recent surveys have found several FSRQs that exhibit spectral properties, particularly the synchrotron peak frequency, similar to HBLs. These objects are potential sources of TeV emission according to several models of blazar jet emission and the evolution of blazars. Measurements of TeV flux or flux upper limits could impact existing theories explaining the links between different blazar types and could have a significant impact on our understanding of the nature of objects that are capable of TeV emission. In particular, the presence ( or absence) of TeV emission from FSRQs could confirm ( or cast doubt on) recent evolutionary models that expect intermediate objects in a transitional state between FSRQ and BL Lac. The Whipple 10 m imaging air Cerenkov gamma-ray telescope is well suited for TeV gamma-ray observations. Using the Whipple telescope, we have taken data on a small selection of nearby (z < 0.1 in most cases) high-peaked FSRQs. Although one of the objects, B2 0321+33, showed marginal evidence of flaring, no significant emission was detected. The implications of this paucity of emission and the derived upper limits are discussed.
C1 Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA.
Univ Leeds, Dept Phys, Leeds LS2 9JT, W Yorkshire, England.
Univ Chicago, Chicago, IL 60637 USA.
Washington Univ, Dept Phys, St Louis, MO 63130 USA.
Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA.
Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA.
Grinnell Coll, Dept Phys, Grinnell, IA 50112 USA.
Natl Univ Ireland, Dept Phys, Dublin 4, Ireland.
Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA.
Adler Planetarium & Astron Museum, Dept Astron, Chicago, IL 60637 USA.
Natl Univ Ireland, Galway, Ireland.
Univ Utah, Salt Lake City, UT 84112 USA.
Univ Arkansas, Dept Phys & Astron, Little Rock, AR 72204 USA.
McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada.
DePauw Univ, Greencastle, IN 46135 USA.
Galway Mayo Inst Technol, Galway, Ireland.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Cork Inst Technol, Dept Phys, Cork, Ireland.
RP Falcone, AD (reprint author), Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA.
RI Hall, Jeter/E-9294-2015; Daniel, Michael/A-2903-2010;
OI Daniel, Michael/0000-0002-8053-7910; Cui, Wei/0000-0002-6324-5772;
Knapp, Johannes/0000-0003-1519-1383; Lang, Mark/0000-0003-4641-4201
NR 43
TC 20
Z9 20
U1 0
U2 3
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2004
VL 613
IS 2
BP 710
EP 715
DI 10.1086/423128
PN 1
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YB
UT WOS:000224303200007
ER
PT J
AU Mason, RE
Wright, G
Pendleton, Y
Adamson, A
AF Mason, RE
Wright, G
Pendleton, Y
Adamson, A
TI Hydrocarbon dust absorption in Seyfert galaxies and ultraluminous
infrared galaxies
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE dust, extinction; galaxies : active; galaxies : individual (NGC 1068,
NGC 7674); galaxies : ISM; galaxies : nuclei; infrared : galaxies
ID DIFFUSE INTERSTELLAR-MEDIUM; ACTIVE GALACTIC NUCLEUS; HYDROGENATED
AMORPHOUS-CARBON; LINE-OF-SIGHT; MICRON SPECTROSCOPY; MIDINFRARED
OBSERVATIONS; ALIPHATIC-HYDROCARBONS; ORGANIC-MATTER; NGC-1068; BAND
AB We present new spectroscopic observations of the 3.4 mum absorption feature in the Seyfert galaxies NGC 1068 and NGC 7674 and the ultraluminous infrared galaxy IRAS 08572+3915. A signature of C - H bonds in aliphatic hydrocarbons, the 3.4 mum feature indicates the presence of organic material in Galactic and extragalactic dust. Here we compare the 3.4 mum feature in all the galaxies in which it has been detected. In several cases, the signal-to-noise ratio and spectral resolution permit a detailed examination of the feature profile, something which has rarely been attempted in extragalactic lines of sight. The 3.4 mum band in these galaxies closely resembles that seen in the Galactic diffuse interstellar medium ( ISM) and in newly formed dust in a protoplanetary nebula. The similarity implies a common carrier for the carbonaceous component of dust, and one which is resistant to processing in the interstellar and/or circumnuclear medium. We also examine the mid-IR spectrum of NGC 1068, because absorption bands in the 5 - 8 mum region further constrain the chemistry of the 3.4 mum band carrier. While weak features like those present in the mid-IR spectrum of diffuse dust toward the Galactic center would be undetectable in NGC 1068, the strong bands found in the spectra of many proposed dust analog materials are clearly absent, eliminating certain candidates and production mechanisms for the carrier. The absence of strong absorption features at 5 - 8 mum is also consistent with the interpretation that the similarity in the 3.4 mum feature in NGC 1068 to that in Galactic lines of sight reflects real chemical similarity in the carbonaceous dust.
C1 Royal Observ, Inst Astron, Edinburgh EH9 3HJ, Midlothian, Scotland.
Royal Observ, UK Astron Technol Ctr, Edinburgh EH9 3HJ, Midlothian, Scotland.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Joint Astron Ctr, Hilo, HI 96720 USA.
RP Mason, RE (reprint author), NOAO Gemini Sci Ctr, 950 N Cherry Ave, Tucson, AZ 85719 USA.
EM rmason@noao.edu; gsw@roe.ac.uk; ypendleton@mail.arc.nasa.gov;
a.adamson@jach.hawaii.edu
OI adamson, andrew/0000-0003-1120-5178
NR 68
TC 29
Z9 30
U1 0
U2 4
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2004
VL 613
IS 2
BP 770
EP 780
DI 10.1086/423316
PN 1
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YB
UT WOS:000224303200012
ER
PT J
AU McCarthy, IG
Balogh, ML
Babul, A
Poole, GB
Horner, DJ
AF McCarthy, IG
Balogh, ML
Babul, A
Poole, GB
Horner, DJ
TI Models of the intracluster medium with heating and cooling: Explaining
the global and structural X-ray properties of clusters
SO ASTROPHYSICAL JOURNAL
LA English
DT Review
DE cosmology : theory; galaxies : clusters : general; X-rays : galaxies :
clusters
ID LUMINOSITY-TEMPERATURE RELATION; FLUX-LIMITED SAMPLE; GALAXY CLUSTERS;
CHANDRA OBSERVATIONS; SCALING RELATIONS; RELAXED CLUSTER; XMM-NEWTON;
DEPROJECTION ANALYSIS; THERMAL CONDUCTION; MOLECULAR-HYDROGEN
AB Nonradiative simulations that only include heating due to gravitational processes fail to match the observed mean X-ray properties of galaxy clusters. As a result, there has recently been increased interest in models in which either radiative cooling or entropy injection (and/or redistribution) plays a central role inmediating the thermal and spatial properties of the intracluster medium. Both sets of models can account for the mean global properties of clusters. Radiative cooling alone, however, results in fractions of cold / cooled baryons in excess of observationally established limits. On the other hand, the simplest entropy-injection models, by design, do not treat the "cooling core'' structure present in many clusters and cannot account for declining entropy profiles toward cluster centers revealed by recent high-resolution X-ray observations. We consider models that marry radiative cooling with entropy injection, and confront model predictions for the global and structural properties of massive clusters with the latest X-ray data. The models successfully and simultaneously reproduce the observed luminosity-temperature (L-T) and luminosity-mass (L-M) relations, yield detailed entropy, surface brightness, and temperature profiles in excellent agreement with observations, and predict a cooled gas fraction that is consistent with observational constraints. More interestingly, the model provides a possible explanation for the significant intrinsic scatter present in the L-T and L-M relations. The model also offers a natural way of distinguishing between clusters classically identified as "cooling flow'' clusters and the relaxed "non-cooling flow'' clusters. The former correspond to systems that experienced only mild levels (less than or similar to300 keV cm(2)) of entropy injection, while the latter are identified as systems that had much higher entropy injection. The dividing line in entropy injection between the two categories corresponds roughly to the cooling threshold for massive clusters. This finding suggests that entropy injection may be an important, if not the primary, factor in determining the class a particular cluster will belong to. These results also suggest that the previously identified relationship between inferred cooling flow strength and the dispersion in the L-T relation is a manifestation of the distribution of cluster entropy-injection levels. This is borne out by the entropy profiles derived from Chandra and XMM-Newton. Finally, the model predicts a relationship between a cluster's central entropy and its core radius, the existence of which we confirm in the observational data.
C1 Univ Victoria, Dept Phys & Astron, Victoria, BC V8P 1A1, Canada.
Univ Durham, Dept Phys, Durham DH1 3LE, England.
NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA.
RP McCarthy, IG (reprint author), Univ Victoria, Dept Phys & Astron, Victoria, BC V8P 1A1, Canada.
EM mccarthy@uvastro.phys.uvic.ca; m.l.balogh@durham.ac.uk; babul@uvic.ca;
gbpoole@uvastro.phys.uvic.ca; horner@astro.umass.edu
OI McCarthy, Ian/0000-0002-1286-483X; Babul, Arif/0000-0003-1746-9529
NR 118
TC 80
Z9 80
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2004
VL 613
IS 2
BP 811
EP 830
DI 10.1086/423267
PN 1
PG 20
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YB
UT WOS:000224303200015
ER
PT J
AU Miller, NA
Owen, FN
Hill, JM
Keel, WC
Ledlow, MJ
Oegerle, WR
AF Miller, NA
Owen, FN
Hill, JM
Keel, WC
Ledlow, MJ
Oegerle, WR
TI The dynamics of A2125
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE galaxies : clusters : individual (A2125); galaxies : evolution; galaxies
: kinematics and dynamics
ID DATA REDUCTION TECHNIQUES; CLUSTERS ABELL 2125; RICH CLUSTERS;
RADIO-EMISSION; GALAXIES; SUBSTRUCTURE; POPULATIONS; ENVIRONS; CATALOG
AB We present 371 galaxy velocities in the field of the very rich cluster A2125 (z approximate to 0.25). These were determined using optical spectroscopy collected over several years from both the WIYN 3.5 m telescope and NOAO Mayall 4 m telescope. Prior studies at a variety of wavelengths ( radio, optical, and X-ray) have indicated that A2125 is a likely cluster-cluster merger, a scenario that we are able to test using our large velocity database. We identified 224 cluster galaxies, which were subjected to a broad range of statistical tests using both positional and velocity information to evaluate the cluster dynamics and substructure. The tests confirmed the presence of substructures within the A2125 system at high significance, demonstrating that A2125 is a complex dynamical system. Comparison of the test results with existing simulations strengthens the merger hypothesis and provides clues about the merger geometry and stage. The merger model for the system can reconcile A2125's low X-ray temperature and luminosity with its apparently high richness and might also explain A2125's high fraction of active galaxies identified in prior radio and optical studies.
C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA.
Natl Radio Astron Observ, Socorro, NM 87801 USA.
Univ Arizona, Large Binocular Telescope Observ, Tucson, AZ 85721 USA.
Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA.
AURA, Gemini Observ, La Serena, Chile.
RP Miller, NA (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 681, Greenbelt, MD 20771 USA.
EM nmiller@stis.gsfc.nasa.gov; fowen@aoc.nrao.edu; jhill@as.arizona.edu;
keel@bildad.astr.ua.edu; mledlow@gemini.edu; william.r.oegerle@nasa.gov
RI Oegerle, William/C-9070-2012;
OI Keel, William/0000-0002-6131-9539
NR 29
TC 13
Z9 13
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2004
VL 613
IS 2
BP 841
EP 850
DI 10.1086/423230
PN 1
PG 10
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YB
UT WOS:000224303200017
ER
PT J
AU Strong, AW
Moskalenko, IV
Reimer, O
AF Strong, AW
Moskalenko, IV
Reimer, O
TI A new determination of the extragalactic diffuse gamma-ray background
from EGRET data
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE cosmic rays; diffuse radiation; diffusion; gamma rays : observations;
gamma rays : theory; ISM : general
ID DARK-MATTER; GALAXY; ANTIPROTONS; CALIBRATION
AB We use the GALPROP model for cosmic-ray propagation to obtain a new estimate of the Galactic component of gamma-rays and show that away from the Galactic plane it gives an accurate prediction of the observed EGRET intensities in the energy range 30 MeV to 50 GeV. On this basis we reevaluate the extragalactic gamma-ray background. We find that for some energies previous work underestimated the Galactic contribution at high latitudes and hence overestimated the background. Our new background spectrum shows a positive curvature similar to that expected for models of the extragalactic emission based on the blazar population.
C1 Max Planck Inst Extraterr Phys, D-85740 Garching, Germany.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Ruhr Univ Bochum, D-44780 Bochum, Germany.
RP Strong, AW (reprint author), Max Planck Inst Extraterr Phys, Postfach 1603, D-85740 Garching, Germany.
EM aws@mpe.mpg.de; igor.moskalenko@gsfc.nasa.gov;
olr@tp4.ruhr-uni-bochum.de
RI Moskalenko, Igor/A-1301-2007; Reimer, Olaf/A-3117-2013
OI Moskalenko, Igor/0000-0001-6141-458X; Reimer, Olaf/0000-0001-6953-1385
NR 21
TC 245
Z9 246
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2004
VL 613
IS 2
BP 956
EP 961
DI 10.1086/423196
PN 1
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YB
UT WOS:000224303200025
ER
PT J
AU Strong, AW
Moskalenko, IV
Reimer, O
AF Strong, AW
Moskalenko, IV
Reimer, O
TI Diffuse Galactic continuum gamma rays: A model compatible with EGRET
data and cosmic-ray measurements
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE cosmic rays; diffusion; Galaxy : general; gamma rays : observations;
gamma rays : theory; ISM : general
ID SOUTHERN MILKY-WAY; SUPERNOVA-REMNANTS; CO SURVEY; RADIAL-DISTRIBUTION;
HELIUM SPECTRA; MOLECULAR CLOUDS; ENERGY-SPECTRA; SOLAR MINIMUM;
EMISSION; GALAXY
AB We present a study of the compatibility of some current models of the diffuse Galactic continuum gamma-rays with EGRET data. A set of regions sampling the whole sky is chosen to provide a comprehensive range of tests. The range of EGRET data used is extended to 100 GeV. The models are computed with our GALPROP cosmic-ray propagation and gamma-ray production code. We confirm that the "conventional model'' based on the locally observed electron and nucleon spectra is inadequate, for all sky regions. A conventional model plus hard sources in the inner Galaxy is also inadequate, since this cannot explain the GeV excess away from the Galactic plane. Models with a hard electron injection spectrum are inconsistent with the local spectrum even considering the expected fluctuations; they are also inconsistent with the EGRET data above 10 GeV. We present a new model that fits the spectrum in all sky regions adequately. Secondary antiproton data were used to fix the Galactic average proton spectrum, while the electron spectrum is adjusted using the spectrum of diffuse emission itself. The derived electron and proton spectra are compatible with those measured locally considering fluctuations due to energy losses, propagation, or possibly details of Galactic structure. This model requires a much less dramatic variation in the electron spectrum than models with a hard electron injection spectrum, and moreover it fits the gamma-ray spectrum better and to the highest EGRET energies. It gives a good representation of the latitude distribution of the gamma-ray emission from the plane to the poles, and of the longitude distribution. We show that secondary positrons and electrons make an essential contribution to Galactic diffuse gamma-ray emission.
C1 Max Planck Inst Extraterr Phys, D-85740 Garching, Germany.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Ruhr Univ Bochum, D-44780 Bochum, Germany.
RP Strong, AW (reprint author), Max Planck Inst Extraterr Phys, Postfach 1603, D-85740 Garching, Germany.
EM aws@mpe.mpg.de; igor.moskalenko@gsfc.nasa.gov;
olr@tp4.ruhr-uni-bochum.de
RI Moskalenko, Igor/A-1301-2007; Reimer, Olaf/A-3117-2013
OI Moskalenko, Igor/0000-0001-6141-458X; Reimer, Olaf/0000-0001-6953-1385
NR 78
TC 337
Z9 340
U1 0
U2 5
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2004
VL 613
IS 2
BP 962
EP 976
DI 10.1086/423193
PN 1
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YB
UT WOS:000224303200026
ER
PT J
AU Peeters, E
Spoon, HWW
Tielens, AGGM
AF Peeters, E
Spoon, HWW
Tielens, AGGM
TI Polycyclic aromatic hydrocarbons as a tracer of star formation?
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE galaxies : ISM; HII regions; infrared : galaxies; infrared : ISM; ISM :
lines and bands; ISM : molecules
ID ULTRALUMINOUS INFRARED GALAXIES; COMPACT HII-REGIONS; NEED ULTRAVIOLET
EXCITATION; LARGE-MAGELLANIC-CLOUD; IR EMISSION FEATURES; ISO
SPECTROSCOPY; PHOTODISSOCIATION REGION; INTERSTELLAR-MEDIUM; REFLECTION
NEBULAE; MU-M
AB Infrared (IR) emission features at 3.3, 6.2, 7.7, 8.6, and 11.3 mum are generally attributed to IR fluorescence from ( mainly) far-ultraviolet (FUV) pumped large polycyclic aromatic hydrocarbon (PAH) molecules. As such, these features trace the FUV stellar flux and are thus a measure of star formation. We examined the IR spectral characteristics of Galactic massive star-forming regions and of normal and starburst galaxies, as well as active galactic nuclei (AGNs) and ultraluminous infrared galaxies (ULIRGs). The goal of this study is to analyze whether PAH features are a good qualitative and/or quantitative tracer of star formation, and hence to evaluate the application of PAH emission as a diagnostic tool in order to identify the dominant processes contributing to the infrared emission from Seyfert galaxies and ULIRGs. We develop a new mid-infrared (MIR)/far-infrared ( FIR) diagnostic diagram based on our Galactic sample and compare it to the diagnostic tools of Genzel and coworkers and Laurent and coworkers, with these diagnostic tools also applied to our Galactic sample. This MIR/FIR diagnostic is derived from the FIR normalized 6.2 mum PAH flux and the FIR normalized 6.2 mum continuum flux. Within this diagram, the Galactic sources form a sequence spanning a range of 3 orders of magnitude in these ratios, ranging from embedded compact H II regions to exposed photodissociation regions (PDRs) and the ( diffuse) interstellar medium ( ISM). However, the variation in the 6.2 mum PAH feature - to - continuum ratio is relative small. Comparison of our extragalactic sample with our Galactic sources revealed an excellent resemblance of normal and starburst galaxies to exposed PDRs. While Seyfert 2 galaxies coincide with the starburst trend, Seyfert 1 galaxies are displaced by at least a factor of 10 in 6.2 mum continuum flux, in accordance with general orientation-dependent unification schemes for AGNs. ULIRGs show a diverse spectral appearance. Some show a typical AGN hot dust continuum. More, however, either are starburst-like or show signs of strong dust obscuration in the nucleus. One characteristic of the ULIRGs also seems to be the presence of more prominent FIR emission than either starburst galaxies or AGNs. We discuss the observed variation in the Galactic sample in view of the evolutionary state and the PAH/dust abundance and discuss the use of PAHs as quantitative tracers of star formation activity. Based on these investigations, we find that PAHs may be better suited as a tracer of B stars, which dominate the Galactic stellar energy budget, than as a tracer of massive star formation (O stars).
C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
Univ Groningen, Kapteyn Inst, Natl Inst Space Res, Space Res Org Netherlands, NL-9700 AV Groningen, Netherlands.
RP Peeters, E (reprint author), NASA, Ames Res Ctr, Mail Stop 245-6, Moffett Field, CA 94035 USA.
EM epeeters@mail.arc.nasa.gov
NR 93
TC 228
Z9 227
U1 1
U2 7
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2004
VL 613
IS 2
BP 986
EP 1003
DI 10.1086/423237
PN 1
PG 18
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YB
UT WOS:000224303200028
ER
PT J
AU Sterling, AC
Moore, RL
AF Sterling, AC
Moore, RL
TI External and internal reconnection in two filament-carrying magnetic
cavity solar eruptions
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE Sun : corona; Sun : coronal mass ejections (CMEs); Sun : flares; Sun :
magnetic fields; Sun : UV radiation
ID CORONAL MASS-EJECTIONS; BRAGG CRYSTAL SPECTROMETER; X-RAY TELESCOPE;
PROMINENCE ERUPTION; EMERGING FLUX; A MISSION; FE-XXV; CA-XIX; FLARES;
DYNAMICS
AB We observe two near-limb solar filament eruptions, one of 2000 February 26 and the other of 2002 January 4. For both we use 195 Angstrom Fe XII images from the Extreme-Ultraviolet Imaging Telescope (EIT) and magnetograms from the Michelson Doppler Imager (MDI), both of which are on the Solar and Heliospheric Observatory (SOHO). For the earlier event we also use soft X-ray telescope (SXT), hard X-ray telescope (HXT), and Bragg Crystal Spectrometer (BCS) data from the Yohkoh satellite, and hard X-ray data from the BATSE experiment on the Compton Gamma Ray Observatory (CGRO). Both events occur in quadrupolar magnetic regions, and both have coronal features that we infer belong to the same magnetic cavity structures as the filaments. In both cases, the cavity and filament first rise slowly at similar to10 km s(-1) prior to eruption and then accelerate to similar to100 km s(-1) during the eruption, although the slow-rise movement for the higher altitude cavity elements is clearer in the later event. We estimate that both filaments and both cavities contain masses of similar to 10(14) - 10(15) and similar to 10(15) - 10(16) g, respectively. We consider whether two specific magnetic reconnection - based models for eruption onset, the "tether cutting'' and the "breakout'' models, are consistent with our observations. In the earlier event, soft X-rays from SXT show an intensity increase during the 12 minute interval over which fast eruption begins, which is consistent with tether-cutting - model predictions. Substantial hard X-rays, however, do not occur until after fast eruption is underway, and so this is a constraint the tether-cutting model must satisfy. During the same 12 minute interval over which fast eruption begins, there are brightenings and topological changes in the corona indicative of high-altitude reconnection early in the eruption, and this is consistent with breakout predictions. In both eruptions, the state of the overlying loops at the time of onset of the fast-rise phase of the corresponding filament can be compared with expectations from the breakout model, thereby setting constraints that the breakout model must meet. Our findings are consistent with both runaway tether-cutting - type reconnection and fast breakout-type reconnection, occurring early in the fast phase of the February eruption and with both types of reconnection being important in unleashing the explosion, but we are not able to say which, if either, type of reconnection actually triggered the fast phase. In any case, we have found specific constraints that either model, or any other model, must satisfy if correct.
C1 NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA.
RP Sterling, AC (reprint author), NASA, George C Marshall Space Flight Ctr, Dept Space Sci, SD50, Huntsville, AL 35812 USA.
EM asterling@solar.stanford.edu; ron.moore@nasa.gov
NR 38
TC 56
Z9 56
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2004
VL 613
IS 2
BP 1221
EP 1232
DI 10.1086/423297
PN 1
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YB
UT WOS:000224303200046
ER
PT J
AU Hindman, BW
Gizon, L
Duvall, TL
Haber, DA
Toomre, J
AF Hindman, BW
Gizon, L
Duvall, TL
Haber, DA
Toomre, J
TI Comparison of solar subsurface flows assessed by ring and time-distance
analyses
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE Sun : helioseismology; Sun : interior; Sun : magnetic fields; Sun :
oscillations; Sun : rotation
ID MICHELSON DOPPLER IMAGER; UPPER CONVECTION ZONE; HELIOSEISMOLOGY;
OSCILLATIONS; DYNAMICS; INTERIOR; SURFACE
AB The solar near-surface shear layer exhibits a rich medley of flows that are now being measured by a variety of local helioseismic techniques. We present comparisons of the horizontal flows obtained with two of these techniques, ring and time-distance analyses, applied to Michelson Doppler Imager (MDI) Dynamics Program data from the years 1998 and 1999. The ring analyses use the frequencies of both f and p modes in inversions to obtain flows within the near-surface shear layer as a function of depth. The f-mode time-distance analyses make velocity inferences just beneath the photosphere. After degrading the spatial resolution of the time-distance analyses to match the coarser resolution of the ring analyses, we find that the flows deduced with the two methods are remarkably similar, with common inflow and outflow sites as well as agreement in flow direction. The flows from ring and time-distance analyses are highly correlated with each other ( correlation coefficients similar to 0.8); direct correspondence of features in the flows is largely realized in both the quiet-Sun and magnetic active regions.
C1 Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA.
NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA.
Stanford Univ, WW Hansen Exper Phys Lab, Stanford, CA 94305 USA.
Univ Colorado, JILA, Boulder, CO 80309 USA.
RP Hindman, BW (reprint author), Univ Colorado, JILA, Boulder, CO 80309 USA.
EM hindman@solarz.colorado.edu; gizon@quake.stanford.edu;
tduvall@solar.stanford.edu; dhaber@solarz.colorado.edu;
jtoomre@solarz.colorado.edu
RI Gizon, Laurent/B-9457-2008; Duvall, Thomas/C-9998-2012;
OI HINDMAN, BRADLEY/0000-0001-7612-6628
NR 27
TC 46
Z9 47
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2004
VL 613
IS 2
BP 1253
EP 1262
DI 10.1086/423263
PN 1
PG 10
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YB
UT WOS:000224303200049
ER
PT J
AU Brown, TM
Ferguson, HC
Smith, E
Kimble, RA
Sweigart, AV
Renzini, A
Rich, RM
VandenBerg, DA
AF Brown, TM
Ferguson, HC
Smith, E
Kimble, RA
Sweigart, AV
Renzini, A
Rich, RM
VandenBerg, DA
TI Age constraints for an M31 globular cluster from main-sequence
photometry
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE galaxies : halos; galaxies : individual (M31); galaxies : star clusters;
galaxies : stellar content
ID STAR-FORMATION HISTORY; METAL-POOR STARS; LICK INDEXES; MILKY-WAY; HALO;
MODELS; POPULATION; ABUNDANCE
AB We present a color-magnitude diagram (CMD) of the globular cluster SKHB 312 in the Andromeda galaxy (M31), obtained with the Advanced Camera for Surveys on the Hubble Space Telescope. The cluster was included in deep observations taken to measure the star formation history of the M31 halo. Overcoming a very crowded field, our photometry of SKHB 312 reaches m(V) approximate to 30.5 mag, more than 1 mag below the main-sequence turnoff. These are the first observations to allow a direct age estimate from the turnoff in an old M31 cluster. We analyze its CMD and luminosity function using a finely spaced grid of isochrones that have been calibrated using observations of Galactic clusters taken with the same camera and filters. The luminosity difference between the subgiant and horizontal branches is approximate to0.2 mag smaller in SKHB 312 than in the Galactic clusters 47 Tuc and NGC 5927, implying that SKHB 312 is 2-3 Gyr younger. A quantitative comparison to isochrones yields an age of 10(-1)(+2.5) Gyr.
C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
European So Observ, D-8046 Garching, Germany.
Univ Calif Los Angeles, Dept Phys & Astron, Div Astron, Los Angeles, CA 90095 USA.
Univ Victoria, Dept Phys & Astron, Victoria, BC V8W 3P6, Canada.
RP Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA.
EM tbrown@stsci.edu; ferguson@stsci.edu; edsmith@stsci.edu;
randy.a.kimble@nasa.gov; allen.v.sweigart@nasa.gov; arenzini@eso.org;
rmr@astro.ucla.edu; davb@uvvm.uvic.ca
OI Brown, Thomas/0000-0002-1793-9968
NR 29
TC 39
Z9 39
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2004
VL 613
IS 2
BP L125
EP L128
DI 10.1086/425178
PN 2
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YC
UT WOS:000224303300011
ER
PT J
AU Finsterle, W
Jefferies, SM
Cacciani, A
Rapex, P
McIntosh, SW
AF Finsterle, W
Jefferies, SM
Cacciani, A
Rapex, P
McIntosh, SW
TI Helioseismic mapping of the magnetic canopy in the solar chromosphere
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE Sun : chromosphere; Sun : helioseismology; Sun : magnetic fields
ID QUIET SUN; ATMOSPHERE; OSCILLATIONS; WAVES
AB We determine the three-dimensional topography of the magnetic canopy in and around active regions by mapping the propagation behavior of high-frequency acoustic waves in the solar chromosphere.
C1 Univ New Mexico, Maui Sci Res Ctr, Kihei, HI 96753 USA.
Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy.
Univ Space Res Assoc, Cooperat Program Space Sci, Seabrook, MD USA.
NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20772 USA.
RP Univ New Mexico, Maui Sci Res Ctr, 590 Lipoa Pkwy,Suite 262, Kihei, HI 96753 USA.
EM wfinsterle@spd.aas.org; stuartj@msrc.unm.edu;
alessandro.cacciani@roma1.infn.it; paolo.rapex@fastwebnet.it;
scott@grace.nascom.nasa.gov
NR 10
TC 45
Z9 45
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2004
VL 613
IS 2
BP L185
EP L188
DI 10.1086/424996
PN 2
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YC
UT WOS:000224303300026
ER
PT J
AU Poletto, G
Suess, ST
Bemporad, A
Schwadron, NA
Elliott, HA
Zurbuchen, TH
Ko, YK
AF Poletto, G
Suess, ST
Bemporad, A
Schwadron, NA
Elliott, HA
Zurbuchen, TH
Ko, YK
TI Evidence for the same hot plasma after coronal mass ejection events, in
both remote and in situ observations
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE solar wind; Sun : coronal mass ejections (CMEs); Sun : UV radiation
ID SOLAR-WIND; ACTIVE-REGION; CURRENT SHEET; COMPLEX
AB We present here evidence for highly ionized Fe observed both in the corona, in the aftermath of a coronal mass ejection, and, after propagation, in situ. The apparent source temperature is greater than 6 MK. To our knowledge, this is the first time that such an unambiguous identification has been made. This detection complements studies correlating other properties of plasma observed in situ to the same properties of the same plasma remotely observed at its source in the corona.
C1 INAF, Arcetri Astrophys Observ, I-50125 Florence, Italy.
NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
Univ Florence, Dipartimento Astron & Sci Spazio, I-50125 Florence, Italy.
SW Res Inst, San Antonio, TX 78238 USA.
Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
RP INAF, Arcetri Astrophys Observ, Largo Enrico Fermi 5, I-50125 Florence, Italy.
EM poletto@arcetri.astro.it; steven.t.suess@nasa.gov;
bemporad@arcetri.astro.it; nschwadron@swri.edu; helliott@swri.edu;
thomasz@umich.edu; yko@cfa.harvard.edu
OI Bemporad, Alessandro/0000-0001-5796-5653
NR 17
TC 9
Z9 9
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD OCT 1
PY 2004
VL 613
IS 2
BP L173
EP L176
DI 10.1086/425136
PN 2
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859YC
UT WOS:000224303300023
ER
PT J
AU Kogut, A
Fixsen, DJ
Levin, S
Limon, M
Lubin, PM
Mirel, P
Seiffert, M
Wollack, E
AF Kogut, A
Fixsen, DJ
Levin, S
Limon, M
Lubin, PM
Mirel, P
Seiffert, M
Wollack, E
TI An instrument to measure the temperature of the cosmic microwave
background radiation at centimeter wavelengths
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE balloons; cosmic microwave background; cosmology : observations
ID UNIVERSE; REIONIZATION; SIGNATURES; SPECTRUM
AB The Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE) is a balloon-borne instrument to measure the temperature of the cosmic microwave background at centimeter wavelengths. ARCADE uses narrowband cryogenic radiometers to compare the sky to an external full-aperture calibrator. To minimize potential sources of systematic error, ARCADE uses a novel open-aperture design that maintains the antennas and calibrator at temperatures near 3 K at the mouth of an open bucket Dewar, without windows or other warm objects between the antennas and the sky. We discuss the design and performance of the ARCADE instrument from its 2001 and 2003 flights.
C1 NASA, Goddard Space Flight Ctr, SSAI, Greenbelt, MD 20771 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA.
RP Kogut, A (reprint author), NASA, Goddard Space Flight Ctr, SSAI, Code 685, Greenbelt, MD 20771 USA.
RI Kogut, Alan/D-6293-2012; Wollack, Edward/D-4467-2012;
OI Wollack, Edward/0000-0002-7567-4451; Limon, Michele/0000-0002-5900-2698
NR 15
TC 19
Z9 19
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD OCT
PY 2004
VL 154
IS 2
BP 493
EP 499
DI 10.1086/422517
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856SL
UT WOS:000224065000002
ER
PT J
AU Pirzkal, N
Xu, C
Malhotra, S
Rhoads, JE
Koekemoer, AM
Moustakas, LA
Walsh, JR
Windhorst, RA
Daddi, E
Cimatti, A
Ferguson, HC
Gardner, JP
Gronwall, C
Haiman, Z
Kummel, M
Panagia, N
Pasquali, A
Stiavelli, M
Alighieri, SD
Tsvetanov, Z
Vernet, J
Yan, H
AF Pirzkal, N
Xu, C
Malhotra, S
Rhoads, JE
Koekemoer, AM
Moustakas, LA
Walsh, JR
Windhorst, RA
Daddi, E
Cimatti, A
Ferguson, HC
Gardner, JP
Gronwall, C
Haiman, Z
Kummel, M
Panagia, N
Pasquali, A
Stiavelli, M
Alighieri, SD
Tsvetanov, Z
Vernet, J
Yan, H
TI Grapes, Grism spectroscopy of the Hubble Ultra Deep Field: Description
and data reduction
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE galaxies : high-redshift; surveys; techniques : spectroscopic
ID ADVANCED CAMERA; GALAXIES
AB We present deep unbiased spectroscopy of the Hubble Ultra Deep Field (UDF) carried out using the slitless grism spectroscopy mode of the Advanced Camera for Surveys on the Hubble Space Telescope (HST). The Grism ACS Program for Extragalactic Science (GRAPES) achieves continuum detection as faint as z(AB) 27.2 using 40 orbits (9.2 x 10(4) s) on HST. The data were taken at four orientation angles to correct for the overlap of spectra. GRAPES data provide a unique, uninterrupted, low-resolution (R 100) spectral coverage for 5500 Angstrom < λ < 10500 Angstrom and allow us to detect high-redshift galaxies at 4 < z < 7 whether they have Lyalpha lines or just show the Lyman break, as well as find low-luminosity active galactic nuclei in an unbiased fashion. This paper describes in detail the observations and the data reduction and examines the quality of the extracted spectra. Subsequent papers will deal with the analysis of the data. The extracted and calibrated GRAPES spectra will be available from MAST at STScI.
C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA.
ESO STECF, D-85748 Garching, Germany.
Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA.
Osserv Astrofis Arcetri, INAF, I-50125 Florence, Italy.
NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA.
Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA.
Columbia Univ, Dept Astron, New York, NY 10027 USA.
ETH Honggerberg, Inst Astron, CH-8093 Zurich, Switzerland.
Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA.
NASA Headquarters, Washington, DC 20546 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
RP Pirzkal, N (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA.
RI Daddi, Emanuele/D-1649-2012; di Serego Alighieri, Sperello/E-4067-2010;
OI Daddi, Emanuele/0000-0002-3331-9590; di Serego Alighieri,
Sperello/0000-0001-8769-2692; Vernet, Joel/0000-0002-8639-8560;
Koekemoer, Anton/0000-0002-6610-2048; Moustakas,
Leonidas/0000-0003-3030-2360
NR 16
TC 77
Z9 77
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD OCT
PY 2004
VL 154
IS 2
BP 501
EP 508
DI 10.1086/422582
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856SL
UT WOS:000224065000003
ER
PT J
AU Swartz, DA
Ghosh, KK
Tennant, AF
Wu, KW
AF Swartz, DA
Ghosh, KK
Tennant, AF
Wu, KW
TI The ultraluminous X-ray source population from the Chandra archive of
galaxies
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Review
DE galaxies : general; surveys; X-rays : binaries; X-rays : galaxies;
X-rays : general
ID MASS BLACK-HOLES; FORMATION RATE INDICATOR; DWARF STARBURST GALAXY;
NEARBY SPIRAL GALAXIES; HUBBLE-SPACE-TELESCOPE; STAR-FORMATION; POINT
SOURCES; STATISTICAL-ANALYSIS; EXTERNAL GALAXIES; ACCRETION DISKS
AB One hundred fifty-four discrete non-nuclear ultraluminous X-ray (ULX) sources, with spectroscopically determined intrinsic X-ray luminosities greater than 10(39) ergs s(-1), are identified in 82 galaxies observed with Chandra's Advanced CCD Imaging Spectrometer. Source positions, X-ray luminosities, and spectral and timing characteristics are tabulated. Statistical comparisons between these X-ray properties and those of the weaker discrete sources in the same fields (mainly neutron star and stellar-mass black hole binaries) are made. Sources above similar to10(38) ergs s(-1) display similar spatial, spectral, color, and variability distributions. In particular, there is no compelling evidence in the sample for a new and distinct class of X-ray object such as the intermediate-mass black holes. Eighty-three percent of ULX candidates have spectra that can be described as absorbed power laws with index [Gamma] = 1.74 and column density [N(H)] = 2.24 x 10(21) cm(-2), or similar to5 times the average Galactic column. About 20% of the ULXs have much steeper indices indicative of a soft, and likely thermal, spectrum. The locations of ULXs in their host galaxies are strongly peaked toward their galaxy centers. The deprojected radial distribution of the ULX candidates is somewhat steeper than an exponential disk, indistinguishable from that of the weaker sources. About 5%-15% of ULX candidates are variable during the Chandra observations (which average 39.5 ks). Comparison of the cumulative X-ray luminosity functions of the ULXs to Chandra Deep Field results suggests similar to25% of the sources may be background objects, including 14% of the ULX candidates in the sample of spiral galaxies and 44% of those in elliptical galaxies, implying the elliptical galaxy ULX population is severely compromised by background active galactic nuclei. Correlations with host galaxy properties confirm the number and total X-ray luminosity of the ULXs are associated with recent star formation and with galaxy merging and interactions. The preponderance of ULXs in star-forming galaxies as well as their similarities to less-luminous sources suggest they originate in a young but short-lived population such as the high-mass X-ray binaries with a smaller contribution (based on spectral slope) from recent supernovae. The number of ULXs in elliptical galaxies scales with host galaxy mass and can be explained most simply as the high-luminosity end of the low-mass X-ray binary population.
C1 NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA.
NASA, George C Marshall Space Flight Ctr, Dept Space Sci, Huntsville, AL 35812 USA.
UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England.
RP Swartz, DA (reprint author), NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, SD50, Huntsville, AL 35812 USA.
NR 129
TC 205
Z9 206
U1 0
U2 4
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD OCT
PY 2004
VL 154
IS 2
BP 519
EP 539
DI 10.1086/422842
PG 21
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856SL
UT WOS:000224065000005
ER
PT J
AU Harmon, BA
Wilson, CA
Fishman, GJ
Connaughton, V
Henze, W
Paciesas, WS
Finger, MH
McCollough, ML
Sahi, M
Peterson, B
Shrader, CR
Grindlay, JE
Barret, D
AF Harmon, BA
Wilson, CA
Fishman, GJ
Connaughton, V
Henze, W
Paciesas, WS
Finger, MH
McCollough, ML
Sahi, M
Peterson, B
Shrader, CR
Grindlay, JE
Barret, D
TI The Burst and Transient Source Experiment (BATSE) earth occultation
catalog of low-energy gamma-ray sources
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Review
DE catalogs; gamma rays : observations; methods : data analysis;
occultations; surveys; X-rays : stars
ID HARD X-RAY; ALL-SKY MONITOR; CYGNUS X-1; GRO J1655-40; MULTIWAVELENGTH
OBSERVATIONS; BEPPOSAX OBSERVATION; SOURCE GRS-1915+105; SPECTRAL
VARIATIONS; SUPERLUMINAL SOURCE; STATE TRANSITION
AB The Burst and Transient Source Experiment (BATSE), aboard the Compton Gamma Ray Observatory (CGRO), provided a record of the low-energy gamma-ray sky (similar to20-1000 keV) between 1991 April and 2000 May (9.1 yr).
BATSE monitored the high-energy sky using the Earth occultation technique (EOT) for point sources whose emission extended for times on the order of the CGRO orbital period (similar to92 min) or greater. Using the EOT to extract flux information, a catalog of sources using data from the BATSE Large Area Detectors has been prepared. The first part of the catalog consists of results from the all-sky monitoring of 58 sources, mostly Galactic, with intrinsic variability on timescales of hours to years. For these sources, we have included tables of flux and spectral data, and outburst times for transients. Light curves (or flux histories) have been placed on the World Wide Web.
We then performed a deep-sampling of these 58 objects, plus a selection of 121 more objects, combining data from the entire 9.1 yr BATSE data set. Source types considered were primarily accreting binaries, but a small number of representative active galaxies, X-ray-emitting stars, and supernova remnants were also included. The sample represents a compilation of sources monitored and/or discovered with BATSE and other high-energy instruments between 1991 and 2000, known sources taken from the HEAO 1 A-4 and Macomb & Gehrels catalogs. The deep sample results include definite detections of 83 objects and possible detections of 36 additional objects. The definite detections spanned three classes of sources: accreting black hole and neutron star binaries, active galaxies, and supernova remnants. The average fluxes measured for the fourth class, the X-ray emitting stars, were below the confidence limit for definite detection.
Flux data for the deep sample are presented in four energy bands: 20-40, 40-70, 70-160, and 160-430 keV. The limiting average flux level (9.1 yr) for the sample varies from 3.5 to 20 mcrab (5 sigma) between 20 and 430 keV, depending on systematic error, which in turn is primarily dependent on the sky location.
To strengthen the credibility of detection of weaker sources (similar to5-25 mcrab), we generated Earth occultation images, searched for periodic behavior using FFT and epoch folding methods, and critically evaluated the energy-dependent emission in the four flux bands. The deep sample results are intended for guidance in performing future all-sky surveys or pointed observations in the hard X-ray and low-energy gamma-ray band, as well as more detailed studies with the BATSE EOT.
C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
Univ Alabama, Huntsville, AL 35899 USA.
NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 04, France.
RP Harmon, BA (reprint author), US DOE, NE50, Germantown, MD 20874 USA.
EM colleen.a.wilson-hodge@nasa.gov
NR 162
TC 40
Z9 40
U1 0
U2 4
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD OCT
PY 2004
VL 154
IS 2
BP 585
EP 622
DI 10.1086/421940
PG 38
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856SL
UT WOS:000224065000009
ER
PT J
AU Willis, AJ
Crowther, PA
Fullerton, AW
Hutchings, JB
Sonneborn, G
Brownsberger, K
Massa, DL
Walborn, NR
AF Willis, AJ
Crowther, PA
Fullerton, AW
Hutchings, JB
Sonneborn, G
Brownsberger, K
Massa, DL
Walborn, NR
TI An atlas of far-ultraviolet spectra of Wolf-Rayet stars from the FUSE
satellite
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE atlases; stars : mass loss; stars : Wolf-Rayet; ultraviolet : stars
ID LARGE-MAGELLANIC-CLOUD; SPECTROSCOPIC-EXPLORER; FUNDAMENTAL PARAMETERS;
TERMINAL VELOCITIES; WC STARS; WIND PROPERTIES; STELLAR WINDS; MASSIVE
STARS; ABUNDANCES; LMC
AB We present an atlas of far-ultraviolet spectra of 21 Wolf-Rayet (WR) stars in the Galaxy and Large and Small Magellanic Clouds, secured with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. The data cover the wavelength range of 912-1190 Angstrom at a spectral resolution of 0.1 Angstrom and span examples of most subtypes in the WN and WC sequences. We discuss the FUV spectral morphology of the different WR sequences, emphasizing the wide range of ions and chemical species exhibiting well-developed P Cygni profiles and emission lines in this wavelength range. For WN stars the relative strengths of C IV/C III, N III/N II, P V/P IV, and Si IV/Si III show a decrease in strength of the high ions from WN3 to WN11 complemented by an increase in the lower ions at later types. The "super ions'' of O VI and S VI are considered photoionized wind features for WN3-WN6 stars, probably the result of Auger ionization in WN7-WN9 stars, and probably absent at WN10-WN11. The WN5h star Sk 41 in the SMC shows relatively weaker features, which can be ascribed to the effects of a global galaxy metal deficiency. For the WC stars, a similar pattern of wind ionization-linked strengths in the emissions and P Cygni profiles is present, particularly evident in the relative strengths of lines in P V, S IV, Si IV, and Si III. O VI, and S VI features are only seen in the earliest WC subtypes. The high carbon abundance in WC stars is reflected by the presence of strong C IV and C III lines throughout the sequence. We present new estimates of the wind terminal velocities from measurements of saturated absorption components observed in a wide range of I. P. species. Considerable revisions to (upsilon)infinity for the WN3 and WN5 (SMC) stars in our sample and, in particular for the WN10 and WN11 stars are found. The latter make use of the unique availability of the N II resonance line in the FUSE waveband.
C1 UCL, Dept Phys & Astron, London WC1E 6BT, England.
Univ Sheffield, Dept Phys & Astron, Sheffield S3 7RH, S Yorkshire, England.
Univ Victoria, Dept Phys & Astron, Victoria, BC V8W 3P6, Canada.
Johns Hopkins Univ, Ctr Astrophys Sci, Dept Phys & Astron, Baltimore, MD USA.
Natl Res Council Canada, Herzberg Inst Astrophys, Dominion Astrophys Observ, Victoria, BC V8X 4M6, Canada.
NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA.
Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA.
Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA.
NASA, Goddard Space Flight Ctr, SGT Inc, Greenbelt, MD 20771 USA.
Space Telescope Sci Inst, Baltimore, MD 21218 USA.
RP Willis, AJ (reprint author), UCL, Dept Phys & Astron, Gower St, London WC1E 6BT, England.
OI Crowther, Paul/0000-0001-6000-6920
NR 46
TC 18
Z9 18
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD OCT
PY 2004
VL 154
IS 2
BP 651
EP 672
DI 10.1086/422825
PG 22
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856SL
UT WOS:000224065000012
ER
PT J
AU Davis, DD
Eisele, F
Chen, G
Crawford, J
Huey, G
Tanner, D
Slusher, D
Mauldin, L
Oncley, S
Lenschow, D
Semmer, S
Shetter, R
Lefer, B
Arimoto, R
Hogan, A
Grube, P
Lazzara, M
Bandy, A
Thornton, D
Berresheim, H
Bingemer, H
Hutterli, M
McConnell, J
Bales, R
Dibb, J
Buhr, M
Park, J
McMurry, P
Swanson, A
Meinardi, S
Blake, D
AF Davis, DD
Eisele, F
Chen, G
Crawford, J
Huey, G
Tanner, D
Slusher, D
Mauldin, L
Oncley, S
Lenschow, D
Semmer, S
Shetter, R
Lefer, B
Arimoto, R
Hogan, A
Grube, P
Lazzara, M
Bandy, A
Thornton, D
Berresheim, H
Bingemer, H
Hutterli, M
McConnell, J
Bales, R
Dibb, J
Buhr, M
Park, J
McMurry, P
Swanson, A
Meinardi, S
Blake, D
TI An overview of ISCAT 2000
SO ATMOSPHERIC ENVIRONMENT
LA English
DT Article
ID SEA-SALT SULFATE; ANTARCTIC ICE-SHEET; METHANE SULFONIC-ACID;
SOUTH-POLE; METHANESULFONIC-ACID; BOUNDARY-LAYER; DIMETHYL-SULFOXIDE;
BIOGENIC SULFUR; OH; CHEMISTRY
AB The Investigation of Sulfur Chemistry in the Antarctic Troposphere (ISCAT) took place over the timer period of 15 November to 31 December in the year 2000. The study location was the Amundsen Scott Station in Antarctica. ISCAT 2000 defines the second phase of a program designed to explore tropospheric chemistry in Antarctica. As in 1998, the 2000 ISCAT study revealed a strong oxidizing environment at South Pole (SP). During the 2000 investigation, however, the suite of measurements was greatly expanded. These new measurements established the recycling of reactive nitro en 9 as a critical component of this unique environment. This paper first presents the historical background leading up to the ISCAT 2000 observations; then it focuses on providing a summary of the year 2000 results and contrasts these with those recorded during 1998. Important developments made during the 2000 study included the recording of SP data for several species being emitted from the snowpack. These included NO, H2O2 and CH2O. In this context, eddy-diffusion flux measurements provided the first quantitative estimates of the SP NO and NOx snow-to-atmosphere fluxes. This study also revealed that HNO3 and HO2NO2 were major sink species for HOx and NOx radicals. And, it identified the critical factors responsible for SP NO levels exceeding those at other polar sites by nearly an order of magnitude.Finally, it reports on the levels of gas phase sulfur species and provides evidence indicating that the absence of DMS at SP is most likely due to its greatly shorten chemical lifetime in the near vicinity of the plateau. It is proposed that this is due to the influence of NO on the distribution of OH in the lower free troposphere over a region that extends well beyond the plateau itself. Details related to each of the above findings plus others can be found in the 11 accompanying Special Issue papers. (C) 2004 Elsevier Ltd. All rights reserved.
C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA.
Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
New Mexico State Univ, Carlsbad Environm Monitoring Res Ctr, Carlsbad, NM 88220 USA.
Lyndon State Coll, Lyndon, VT 05851 USA.
Univ Wisconsin, Antarct Meteorol Res Ctr, Madison, WI 53706 USA.
Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA.
Univ Frankfurt, Inst Meteorol & Geophys, D-6000 Frankfurt, Germany.
Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA.
Desert Res Inst, Div Hydrol Sci, Reno, NV USA.
Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA.
Sonoma Tech & Air Qual Design, Golden, CO USA.
Univ Minnesota, Dept Mech Engn, Minneapolis, MN 55455 USA.
Univ Calif Irvine, Dept Chem, Irvine, CA 92717 USA.
RP Davis, DD (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA.
EM dd1l6@prism.gatech.edu
RI Berresheim, Harald/F-9670-2011; Crawford, James/L-6632-2013; McMurry,
Peter/A-8245-2008; Lefer, Barry/B-5417-2012;
OI Crawford, James/0000-0002-6982-0934; McMurry, Peter/0000-0003-1609-5131;
Lefer, Barry/0000-0001-9520-5495; LENSCHOW, DONALD/0000-0003-4353-0098
NR 40
TC 25
Z9 26
U1 1
U2 11
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 1352-2310
J9 ATMOS ENVIRON
JI Atmos. Environ.
PD OCT
PY 2004
VL 38
IS 32
BP 5363
EP 5373
DI 10.1016/j.atmosenv.2004.05.037
PG 11
WC Environmental Sciences; Meteorology & Atmospheric Sciences
SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences
GA 859QQ
UT WOS:000224283400001
ER
PT J
AU Davis, D
Chen, G
Buhr, M
Crawford, J
Lenschow, D
Lefer, B
Shetter, R
Eisele, F
Mauldin, L
Hogan, A
AF Davis, D
Chen, G
Buhr, M
Crawford, J
Lenschow, D
Lefer, B
Shetter, R
Eisele, F
Mauldin, L
Hogan, A
TI South Pole NOx chemistry: an assessment of factors controlling
variability and absolute levels
SO ATMOSPHERIC ENVIRONMENT
LA English
DT Article
DE Antarctica; South Pole; photochemistry; NO; NOx; snow emissions; ISCAT
ID BOUNDARY-LAYER; ANTARCTIC SNOW; PHOTOCHEMICAL NO; GREENLAND; NITRATE;
SUMMIT; OZONE; EMISSIONS; NO(X); OH
AB Several groups have now shown that snow covered polar areas can lead to the release of NO, to the atmosphere as a result of the UV photolysis of nitrate ions. Here we focus on a detailed examination of the NO observations recorded at South Pole (SP). Topics explored include: (1) why SP NOx levels greatly exceed those at other polar sites; (2) what processes are responsible for the observed large day to day NO concentration shifts at SP; and (3) possible explanations for the large variability in NO seen between SP studies in 1998 and 2000. As discussed in the main body of the text, the answer to all three questions lies in the uniqueness of the summertime SP environment. Among these characteristics is the presence of a large plateau region just to the east of SP. This region defines one of the world's largest air drainage fields, being nearly 1000 kin across and having elevation of similar to 3 km. In addition, summertime SP surface temperatures typically do not exceed -25degrees C, leading to frequent cases where strong near surface temperature inversions occur. It experiences 24 h of continuous sunlight, giving rise to non-stop photochemical reactions both within the snowpack and in the atmosphere. The latter chemistry is unique at SP in that increasing levels of NOx lead to an enhanced lifetime for NOx, thereby producing non-linear increases in NOx. In addition, the rapid atmospheric oxidation of NOx, in conjunction with very rapid dry deposition of the products (HNO3 and HO2NO2), results in a very efficient recycling of NOx back to the snowpack. Details concerning these unique SP characteristics and the extension of these findings to the greater plateau region are discussed. Finally, the relationship of NOx recycling and total nitrogen deposition to the plateau is explored. (C) 2004 Elsevier Ltd. All rights reserved.
C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA.
NASA, Langley Res Ctr, Hampton, VA 23665 USA.
Sonoma Tech & Air Qual Design, Golden, CO USA.
Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA.
RP Davis, D (reprint author), Georgia Inst Technol, Sch Earth & Atmospher Sci, Environm Sci & Technol Bldgs,311 Frest St, Atlanta, GA 30332 USA.
EM douglas.davis@eas.gatech.edu
RI Crawford, James/L-6632-2013; Lefer, Barry/B-5417-2012;
OI Crawford, James/0000-0002-6982-0934; Lefer, Barry/0000-0001-9520-5495;
LENSCHOW, DONALD/0000-0003-4353-0098
NR 29
TC 71
Z9 73
U1 0
U2 11
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 1352-2310
J9 ATMOS ENVIRON
JI Atmos. Environ.
PD OCT
PY 2004
VL 38
IS 32
BP 5375
EP 5388
DI 10.1016/j.atmosenv.2004.04.039
PG 14
WC Environmental Sciences; Meteorology & Atmospheric Sciences
SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences
GA 859QQ
UT WOS:000224283400002
ER
PT J
AU Chen, G
Davis, D
Crawford, J
Hutterli, LM
Huey, LG
Slusher, D
Mauldin, L
Eisele, F
Tanner, D
Dibb, J
Buhr, M
McConnell, J
Lefer, B
Shetter, R
Blake, D
Song, CH
Lombardi, K
Arnoldy, J
AF Chen, G
Davis, D
Crawford, J
Hutterli, LM
Huey, LG
Slusher, D
Mauldin, L
Eisele, F
Tanner, D
Dibb, J
Buhr, M
McConnell, J
Lefer, B
Shetter, R
Blake, D
Song, CH
Lombardi, K
Arnoldy, J
TI A reassessment of HOx South Pole chemistry based on observations
recorded during ISCAT 2000
SO ATMOSPHERIC ENVIRONMENT
LA English
DT Article
DE Antarctica; South Pole; photochemistry; HOx; snow emissions; ISCAT
ID PEM-TROPICS-B; TO-FIRN TRANSFER; PHOTOCHEMICAL PRODUCTION; ARCTIC
TROPOSPHERE; BOUNDARY-LAYER; OH; MODEL; SNOW; ATMOSPHERE; PACIFIC
AB Reported here are modeling results based on ISCAT (Investigation of Sulfur Chemistry of Antarctic Troposphere) 2000 observations recorded at the South Pole (SP) during the Austral Summer of 2000. The observations included a comprehensive set of photochemical parameters, e.g., NO, O-3, and CO. It is worthy to note that not only were OH and HO2 observed, but also HOx precursor species CH2O, H2O2, and HONO were measured. Previous studies have suggested that HONO is the major source of OH/HOx in the Arctic; however, observed HONO levels at SP induced dramatic model overprediction of both HOx and NOx when used to constrain the model calculations. In contrast, model predictions constrained by observed values of CH2O and H2O2 are consistent with the observations of OH and HO2 (i.e., within 20%) for more than half of the data. Significant model overpredictions of OH, however, were seen at the NO levels lower than 50 pptv or higher than 150 pptv. An analysis of HOx budget at the median NO level suggests that snow emissions of H2O2 and CH2O are the single most important primary source of SP HOx, contributing 46% to the total source. Major sinks for HOx are found to be dry deposition of HO2NO2 and HNO3 as well as their reactions with OH. Although ISCAT 2000 led to a major progress in our understanding of SP HOx, chemistry, critical aspects of this chemistry are still in need of further investigation. (C) 2004 Elsevier Ltd. All rights reserved.
C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA.
Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA.
Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA.
Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA.
Univ New Hampshire, Inst Study Earth Oceans & Space, Climate Change Res Ctr, Durham, NH USA.
Desert Res Inst, Div Hydrol Sci, Reno, NV USA.
Univ Calif Irvine, Dept Chem, Irvine, CA 92717 USA.
RP Chen, G (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA.
EM izao.chen-1@nasa.gov
RI Crawford, James/L-6632-2013; Lefer, Barry/B-5417-2012
OI Crawford, James/0000-0002-6982-0934; Lefer, Barry/0000-0001-9520-5495
NR 31
TC 58
Z9 58
U1 0
U2 10
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 1352-2310
J9 ATMOS ENVIRON
JI Atmos. Environ.
PD OCT
PY 2004
VL 38
IS 32
BP 5451
EP 5461
DI 10.1016/j.atmosenv.2003.07.018
PG 11
WC Environmental Sciences; Meteorology & Atmospheric Sciences
SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences
GA 859QQ
UT WOS:000224283400008
ER
PT J
AU Pinker, RT
Pandithurai, G
Holben, BN
Keefer, TO
Goodrich, D
AF Pinker, RT
Pandithurai, G
Holben, BN
Keefer, TO
Goodrich, D
TI Aerosol radiative properties in the semiarid Western United States
SO ATMOSPHERIC RESEARCH
LA English
DT Article
DE aerosols; aerosols in semiarid region
ID SKY RADIANCE MEASUREMENTS; COLUMNAR WATER-VAPOR; OPTICAL DEPTH;
TROPOSPHERIC AEROSOLS; SURFACE; AERONET; ATMOSPHERE; SUN; SENSITIVITY;
INSTRUMENT
AB Characterization of aerosol optical properties, such as aerosol optical depth, Angstrom exponent, and volume size distribution at the semiarid site of Tombstone Arizona (31degrees23' N, 110degrees05' W, 1408 m) will be presented for one annual cycle. In this region, extensive observations of selected optical parameters such as aerosol optical depth (AOD) have been made in the past and reported on in the literature. Less is known about other optical characteristics that are important in climate modeling and remote sensing. New observational techniques and inversion methods allow for the expansion of the earlier information. Observations have been taken with a state of the art sun photometer for a 1-year period and their analysis will be presented here. Monthly mean AODs at 500 nm were found to be in the range of 0.03-0.12; the monthly mean Angstrom exponent ranged from 0.9 to 1.6, being higher in spring and summer and lower in late fall and winter. Volume size distributions exhibit clear dominance of smaller particles, with a gradual increase in size from winter to spring and into summer. Annual variation of the radii of the smaller and the larger particles ranged between 0.05-0.4 and 4-8 mum, respectively. Radiance measurements at 940 nm were used to estimate precipitable water. The retrieved values compared within limits of uncertainty with independently derived estimates from the National Center for Environmental Prediction (NCEP) regional weather forecast model. An this study was the consistency found in aerosol optical depths as observed in this study and those derived about two decades ago. (C) 2004 Elsevier B.V. All rights reserved.
C1 Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA.
Indian Inst Trop Meteorol, Pune, Maharashtra, India.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
ARS, USDA, SW Watershed Res Ctr, Tucson, AZ USA.
RP Pinker, RT (reprint author), Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA.
EM pinker@atmos.umd.edu
RI Pinker, Rachel/F-6565-2010; Goodrich, David/B-1763-2009;
OI Goodrich, David/0000-0001-7735-1448; Pandithurai, G/0000-0001-7324-3773
NR 34
TC 9
Z9 9
U1 0
U2 2
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0169-8095
J9 ATMOS RES
JI Atmos. Res.
PD OCT
PY 2004
VL 71
IS 4
BP 243
EP 252
DI 10.1016/j.atmosres.2004.06.002
PG 10
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 859ZJ
UT WOS:000224306600002
ER
PT J
AU Jiang, JH
Wu, DL
AF Jiang, Jonathan H.
Wu, Dong L.
TI Ice and water permittivities for millimeter and sub-millimeter remote
sensing applications
SO ATMOSPHERIC SCIENCE LETTERS
LA English
DT Article
DE cloud ice and water; microwave remote sensing; complex permittivity
AB Recent advances in satellite remote sensing at near-millimeter and sub-millimeter wavelengths (similar to 100-3000 GHz) require accurate complex permittivity for ice and liquid water at these frequencies for different temperatures, especially for cold atmospheric conditions. This paper summarizes the existing experimental permittivity data in the literature and provides an updated empirical ice permittivity model for radiative transfer calculations for ground and space remote sensing experiments. Applications of this permittivity model to Microwave Limb Sounder (MLS) cloud measurements are discussed. Copyright (C) 2004 Royal Meteorological Society
C1 [Jiang, Jonathan H.; Wu, Dong L.] CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA.
RP Jiang, JH (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA.
EM Jonathan.H.Jiang@jpl.nasa.gov
RI Wu, Dong/D-5375-2012
FU National Aeronautics and Space Administration
FX The authors wish to express their gratitude to Christian Matzler, Joe
Waters, Paul Wagner and Van Snyder for helpful comments and suggestions.
This work was conducted at the Jet Propulsion Laboratory, California
Institute of Technology, under contract with the National Aeronautics
and Space Administration.
NR 23
TC 41
Z9 41
U1 0
U2 3
PU WILEY-BLACKWELL
PI MALDEN
PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA
SN 1530-261X
J9 ATMOS SCI LETT
JI Atmos. Sci. Lett.
PD OCT-DEC
PY 2004
VL 5
IS 7
BP 146
EP 151
DI 10.1002/asl.77
PG 6
WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
GA V19WE
UT WOS:000208101700002
ER
PT J
AU Evans, JM
Stenger, MB
Moore, FB
Hinghofer-Szalkay, H
Rossler, A
Patwardhan, AR
Brown, DR
Ziegler, MG
Knapp, CF
AF Evans, JM
Stenger, MB
Moore, FB
Hinghofer-Szalkay, H
Rossler, A
Patwardhan, AR
Brown, DR
Ziegler, MG
Knapp, CF
TI Centrifuge training increases presyncopal orthostatic tolerance in
ambulatory men
SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE
LA English
DT Article
DE blood pressure; cardiac output; heart rate; catecholamines; plasma
volume; plasma proteins; vasovagal syncope; vascular resistance; stroke
volume; baroreflex; acceleration
ID DOWN BED REST; HEAD-UP TILT; ISOTONIC EXERCISE; HEALTHY-MEN;
SPACEFLIGHT; RESPONSES; PRESSURE; ENDURANCE
AB Introduction: Exposure to spaceflight or simulations of microgravity reduce human postflight orthostatic tolerance. Exercise training and volume loading can reduce associated losses of plasma volume and muscle strength, but are not successful in maintaining postflight orthostatic tolerance. A preliminary study (16) indicated that short bouts of artificial gravity (AG) training on a centrifuge could increase orthostatic tolerance in healthy, ambulatory volunteers. We tested the same AG protocol for its tolerance effect on 14 men who underwent a 3-wk exposure to G(z) acceleration training on NASA-Ames' (Moffet Field, CA) human-powered centrifuge. Methods: Subjects trained supine (head near the center of rotation) and in pairs (one subject rode passively while the other provided power to operate the 1.9-m centrifuge). The acceleration profile consisted of 7 min at 1 Gz before alternating between 1 and 2.5 Gz at 2-min intervals for 28 min. Each subject's presyncopal orthostatic tolerance limit (to a combination of 70degrees head-up tilt and increasing lower body negative pressure) was determined before and after training. Results: There were no significant differences between training groups, but presyncopal orthostatic tolerance time was improved 17 +/- 10% (p < 0.05) for the combined groups. Mechanisms associated with increased tolerance included: increased cardiac output (p < 0.04), stroke volume (p < 0.01) and low-frequency spectral power of arterial pressure (p < 0.006), and decreased arterial pressure (p < 0.05) and vascular resistance (p < 0.04). Artificial gravity training in this group of men appears to increase orthostatic tolerance through a combination of decreased vascular resistance and enhanced cardiac function.
C1 Univ Kentucky, Ctr Biomed Engn, Lexington, KY 40506 USA.
NASA, Ames Res Ctr Biol & Gravitat Res, Moffett Field, CA USA.
Univ Calif San Diego, Dept Med, San Diego, CA 92103 USA.
Inst Adapt & Spaceflight Physiol, Graz, Austria.
Med Univ Graz, Dept Syst Physiol, Graz, Austria.
RP Evans, JM (reprint author), Univ Kentucky, Ctr Biomed Engn, Lexington, KY 40506 USA.
EM jevans1@uky.edu
RI Roessler, Andreas/A-5751-2008
FU NCRR NIH HHS [M01RR00827]
NR 29
TC 23
Z9 27
U1 0
U2 3
PU AEROSPACE MEDICAL ASSOC
PI ALEXANDRIA
PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA
SN 0095-6562
J9 AVIAT SPACE ENVIR MD
JI Aviat. Space Environ. Med.
PD OCT
PY 2004
VL 75
IS 10
BP 850
EP 858
PG 9
WC Public, Environmental & Occupational Health; Medicine, General &
Internal; Sport Sciences
SC Public, Environmental & Occupational Health; General & Internal
Medicine; Sport Sciences
GA 858HE
UT WOS:000224182100003
PM 15497364
ER
PT J
AU Lowery, TJ
Bunker, J
Zhang, B
Costen, R
Watt, GD
AF Lowery, TJ
Bunker, J
Zhang, B
Costen, R
Watt, GD
TI Kinetic studies of iron deposition in horse spleen ferritin using H2O2
and O-2 as oxidants
SO BIOPHYSICAL CHEMISTRY
LA English
DT Article
DE horse spleen ferritin; iron deposition; kinetics; H2O2 oxidation;
ferroxidase center
ID HYDROGEN-PEROXIDE; FERROXIDASE REACTION; APOFERRITIN; OXIDATION;
INTERMEDIATE; HYDROLYSIS; STORAGE; MINERALIZATION; BINDING; DECAY
AB The reaction of horse spleen ferritin (HoSF) with Fe2+ at pH 6.5 and 7.5 using O-2, H2O2 and 1:1 a mixture of both showed that the iron deposition reaction using H2O2 is similar to20- to 50-fold faster than the reaction with O-2 alone. When H2O2 was added during the iron deposition reaction initiated with O-2 as oxidant, Fe2+ was preferentially oxidized by H2O2, consistent with the above kinetic measurements. Both the O-2 and H2O2 reactions were well defined from 15 to 40 degreesC from which activation parameters were determined. The iron deposition reaction was also studied using O-2 as oxidant in the presence and absence of catalase using both stopped-flow and pumped-flow measurements. The presence of catalase decreased the rate of iron deposition by similar to1.5-fold, and gave slightly smaller absorbance changes than in its absence. From the rate constants for the O-2 (0.044 s(-1)) and H2O2 (0.67 s(-1)) iron-deposition reactions at pH 7.5, simulations of steady-state H2O2 concentrations were computed to be 0.45 muM. This low value and reported Fe2+/O-2 values of 2.0-2.5 are consistent with H2O2 rapidly reacting by an alternate but unidentified pathway involving a system component such as the protein shell or the mineral core as previously postulated. (C) 2004 Elsevier B.V. All rights reserved.
C1 Brigham Young Univ, Dept Chem & Biochem, Provo, UT 84602 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Watt, GD (reprint author), Brigham Young Univ, Dept Chem & Biochem, C100 BNSN, Provo, UT 84602 USA.
EM gdwatt@chem.byu.edu
NR 29
TC 9
Z9 9
U1 1
U2 3
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0301-4622
J9 BIOPHYS CHEM
JI Biophys. Chem.
PD OCT 1
PY 2004
VL 111
IS 2
BP 173
EP 181
DI 10.1016/j.bpc.2004.05.008
PG 9
WC Biochemistry & Molecular Biology; Biophysics; Chemistry, Physical
SC Biochemistry & Molecular Biology; Biophysics; Chemistry
GA 862AV
UT WOS:000224462800008
PM 15381314
ER
PT J
AU Diner, DJ
Ackerman, TP
Anderson, TL
Bosenberg, J
Braverman, AJ
Charlson, RJ
Collins, WD
Davies, R
Holben, BN
Hostetler, CA
Kahn, RA
Martonchik, JV
Menzies, RT
Miller, MA
Ogren, JA
Penner, JE
Rasch, PJ
Schwartz, SE
Seinfeld, JH
Stephens, GL
Torres, O
Travis, LD
Wielicki, BA
Yu, B
AF Diner, DJ
Ackerman, TP
Anderson, TL
Bosenberg, J
Braverman, AJ
Charlson, RJ
Collins, WD
Davies, R
Holben, BN
Hostetler, CA
Kahn, RA
Martonchik, JV
Menzies, RT
Miller, MA
Ogren, JA
Penner, JE
Rasch, PJ
Schwartz, SE
Seinfeld, JH
Stephens, GL
Torres, O
Travis, LD
Wielicki, BA
Yu, B
TI PARAGON - An integrated approach for characterizing aerosol climate
impacts and environmental interactions
SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
LA English
DT Article
ID POLLUTION; ALBEDO
AB Aerosols exert myriad influences on the earth's environment and climate, and on human health. The complexity of aerosol-related processes requires that information gathered to improve our understanding of climate change must originate from multiple sources, and that effective strategies for data integration need to be established. While a vast array of observed and modeled data are becoming available, the aerosol research community currently lacks the necessary tools and infrastructure to reap maximum scientific benefit from these data. Spatial and temporal sampling differences among a diverse set of sensors, nonuniform data qualities, aerosol mesoscale variabilities, and difficulties in separating cloud effects are some of the challenges that need to be addressed. Maximizing the long-term benefit from these data also requires maintaining consistently well-understood accuracies as measurement approaches evolve and improve. Achieving a comprehensive understanding of how aerosol physical, chemical, and radiative processes impact the earth system can be achieved only through a multidisciplinary, inter-agency, and international initiative capable of dealing with these issues. A systematic approach, capitalizing on modern measurement and modeling techniques, geospatial statistics methodologies, and high-performance information technologies, can provide the necessary machinery to support this objective. We outline a framework for integrating and interpreting observations and models, and establishing an accurate, consistent, and cohesive long-term record, following a strategy whereby information and tools of progressively greater sophistication are incorporated as problems of increasing complexity are tackled. This concept is named the Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON). To encompass the breadth of the effort required, we present a set of recommendations dealing with data interoperability; measurement and model integration; multisensor synergy; data summarization and mining; model evaluation; calibration and validation; augmentation of surface and in situ measurements; advances in passive and active remote sensing; and design of satellite missions. Without an initiative of this nature, the scientific and policy communities will continue to struggle with understanding the quantitative impact of complex aerosol processes on regional and global climate change and air quality.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Pacific NW Natl Lab, Richland, WA USA.
Univ Washington, Seattle, WA 98195 USA.
Max Planck Inst Meteorol, Hamburg, Germany.
Natl Ctr Atmospher Res, Boulder, CO 80307 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
NASA, Langley Res Ctr, Hampton, VA 23665 USA.
Brookhaven Natl Lab, Upton, NY 11973 USA.
NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA.
Univ Michigan, Ann Arbor, MI 48109 USA.
CALTECH, Pasadena, CA 91125 USA.
Colorado State Univ, Ft Collins, CO 80523 USA.
Univ Maryland Baltimore Cty, Baltimore, MD 21228 USA.
NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
Univ Calif Berkeley, Berkeley, CA 94720 USA.
RP CALTECH, Jet Prop Lab, Mail Stop 169-237,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM djd@jord.jpl.nasa.gov
RI Davies, Roger/D-4296-2009; Schwartz, Stephen/C-2729-2008; Penner,
Joyce/J-1719-2012; Kahn, Ralph/D-5371-2012; Collins,
William/J-3147-2014; Torres, Omar/G-4929-2013; Ogren, John/M-8255-2015
OI Davies, Roger/0000-0002-2991-0409; Schwartz,
Stephen/0000-0001-6288-310X; Kahn, Ralph/0000-0002-5234-6359; Collins,
William/0000-0002-4463-9848; Ogren, John/0000-0002-7895-9583
NR 22
TC 39
Z9 41
U1 1
U2 7
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0003-0007
EI 1520-0477
J9 B AM METEOROL SOC
JI Bull. Amer. Meteorol. Soc.
PD OCT
PY 2004
VL 85
IS 10
BP 1491
EP 1501
DI 10.1175/BAMS-85-10-1491
PG 11
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 865GF
UT WOS:000224689900010
ER
PT J
AU Seinfeld, JH
Kahn, RA
Anderson, TL
Charlson, RJ
Davies, R
Diner, DJ
Ogren, JA
Schwartz, SE
Wielicki, BA
AF Seinfeld, JH
Kahn, RA
Anderson, TL
Charlson, RJ
Davies, R
Diner, DJ
Ogren, JA
Schwartz, SE
Wielicki, BA
TI Scientific objectives, measurement needs, and challenges motivating the
PARAGON aerosol initiative
SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
LA English
DT Article
ID OPTICAL DEPTH; CLOUD COVER; TROPOSPHERIC AEROSOLS; SULFATE AEROSOLS;
AIR-POLLUTION; SATELLITE; PARAMETERS; RETRIEVAL; RESOLUTION; OCEAN
AB Aerosols are involved in a complex set of processes that operate across many spatial and temporal scales. Understanding these processes, and ensuring their accurate representation in models of transport, radiation transfer, and climate, requires knowledge of aerosol physical, chemical, and optical properties and the distributions of these properties in space and time. To derive aerosol climate forcing, aerosol optical and microphysical properties and their spatial and temporal distributions, and aerosol interactions with clouds, need to be understood. Such data are also required in conjunction with size-resolved chemical composition in order to evaluate chemical transport models and to distinguish natural and anthropogenic forcing. Other basic parameters needed for modeling the radiative influences of aerosols are surface reflectivity and three-dimensional cloud fields. This large suite of parameters mandates an integrated observing and modeling system of commensurate scope. The Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON) concept, designed to meet this requirement, is motivated by the need to understand climate system sensitivity to changes in atmospheric constituents, to reduce climate model uncertainties, and to analyze diverse collections of data pertaining to aerosols. This paper highlights several challenges resulting from the complexity of the problem. Approaches for dealing with them are offered in the set of companion papers.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Washington, Seattle, WA 98195 USA.
NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA.
Brookhaven Natl Lab, Upton, NY 11973 USA.
NASA, Langley Res Ctr, Hampton, VA 23665 USA.
RP Diner, DJ (reprint author), CALTECH, Jet Prop Lab, Mail Stop 169-237,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM djd@jord.jpl.nasa.gov
RI Davies, Roger/D-4296-2009; Schwartz, Stephen/C-2729-2008; Kahn,
Ralph/D-5371-2012; Ogren, John/M-8255-2015
OI Davies, Roger/0000-0002-2991-0409; Schwartz,
Stephen/0000-0001-6288-310X; Kahn, Ralph/0000-0002-5234-6359; Ogren,
John/0000-0002-7895-9583
NR 40
TC 11
Z9 12
U1 0
U2 2
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0003-0007
J9 B AM METEOROL SOC
JI Bull. Amer. Meteorol. Soc.
PD OCT
PY 2004
VL 85
IS 10
BP 1503
EP +
DI 10.1175/BAMS-85-10-1503
PG 8
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 865GF
UT WOS:000224689900011
ER
PT J
AU Kahn, RA
Ogren, JA
Ackerman, TP
Bosenberg, J
Charlson, RJ
Diner, DJ
Holben, BN
Menzies, RT
Miller, MA
Seinfeld, JH
AF Kahn, RA
Ogren, JA
Ackerman, TP
Bosenberg, J
Charlson, RJ
Diner, DJ
Holben, BN
Menzies, RT
Miller, MA
Seinfeld, JH
TI Aerosol data sources and their roles within PARAGON
SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
LA English
DT Article
ID EMITTED RADIANCE INTERFEROMETER; RESEARCH SCANNING POLARIMETER; OPTICAL
DEPTH; UNITED-STATES; IMAGING SPECTRORADIOMETER; TROPOSPHERIC AEROSOLS;
SIZE DISTRIBUTIONS; SATELLITE DATA; SAHARAN DUST; RETRIEVAL
AB We briefly but systematically review major sources of aerosol data, emphasizing suites of measurements that seem most likely to contribute to assessments of global aerosol climate forcing. The strengths and limitations of existing satellite, surface, and aircraft remote sensing systems are described, along with those of direct sampling networks and ship-based stations. It is evident that an enormous number of aerosol-related observations have been made, on a wide range of spatial and temporal sampling scales, and that many of the key gaps in this collection of data could be filled by technologies that either exist or are expected to be available in the near future. Emphasis must be given to combining remote sensing and in situ active and passive observations and integrating them with aerosol chemical transport models, in order to create a more complete environmental picture, having sufficient detail to address current climate forcing questions. The Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON) initiative would provide an organizational framework to meet this goal.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA.
Pacific NW Natl Lab, Richland, WA USA.
Max Planck Inst Meteorol, Hamburg, Germany.
Univ Washington, Seattle, WA 98195 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Brookhaven Natl Lab, Upton, NY 11973 USA.
RP Diner, DJ (reprint author), CALTECH, Jet Prop Lab, 169-237,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM djd@jord.ipl.nasa.gov
RI Kahn, Ralph/D-5371-2012; Ogren, John/M-8255-2015
OI Kahn, Ralph/0000-0002-5234-6359; Ogren, John/0000-0002-7895-9583
NR 86
TC 23
Z9 23
U1 0
U2 3
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0003-0007
J9 B AM METEOROL SOC
JI Bull. Amer. Meteorol. Soc.
PD OCT
PY 2004
VL 85
IS 10
BP 1511
EP +
DI 10.1175/BAMS-85-10-1511
PG 13
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 865GF
UT WOS:000224689900012
ER
PT J
AU Ackerman, TP
Braverman, AJ
Diner, DJ
Anderson, TL
Kahn, RA
Martonchik, JV
Penner, JE
Rasch, PJ
Wielicki, BA
Yu, B
AF Ackerman, TP
Braverman, AJ
Diner, DJ
Anderson, TL
Kahn, RA
Martonchik, JV
Penner, JE
Rasch, PJ
Wielicki, BA
Yu, B
TI Integrating and interpreting aerosol observations and models within the
PARAGON framework
SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
LA English
DT Article
ID PARTICLE-SIZE DISTRIBUTION; SKY RADIANCE MEASUREMENTS; SPACE-TIME
MODELS; OPTICAL-PROPERTIES; INDOEX AEROSOL; SAHARAN DUST; SATELLITE;
CLIMATE; OCEAN; TRANSPORT
AB Given the breadth and complexity of available data, constructing a measurement-based description of global tropospheric aerosols that will effectively confront and constrain global three-dimensional models is a daunting task. Because data are obtained from multiple sources and acquired with nonuniform spatial and temporal sampling, scales, and coverage, protocols need to be established that will organize this vast body of knowledge. Currently, there is no capability to assemble the existing aerosol data into a unified, interoperable whole. Technology advancements now being pursued in high-performance distributed computing initiatives can accomplish this objective. Once the data are organized, there are many approaches that can be brought to bear upon the problem of integrating data from different sources. These include data-driven approaches, such as geospatial statistics formulations, and model-driven approaches, such as assimilation or chemical transport modeling. Establishing a data interoperability framework will stimulate algorithm development and model validation and will facilitate the exploration of synergies between different data types. Data summarization and mining techniques can be used to make statistical inferences about climate system relationships and interpret patterns of aerosol-induced change. Generating descriptions of complex, nonlinear relationships among multiple parameters is critical to climate model improvement and validation. Finally, determining the role of aerosols in past and future climate change ultimately requires the use of fully coupled climate and chemistry models, and the evaluation of these models is required in order to trust their results. The set of recommendations presented here address one component of the Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON) initiative. Implementing them will produce the most accurate four-dimensional representation of global aerosols, which can then be used for testing, constraining, and validating models. These activities are critical components of a sustained program to quantify aerosol effects on global climate.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Pacific NW Natl Lab, Richland, WA USA.
Univ Washington, Seattle, WA 98195 USA.
Univ Michigan, Ann Arbor, MI 48109 USA.
Natl Ctr Atmospher Res, Boulder, CO 80307 USA.
NASA, Langley Res Ctr, Hampton, VA 23665 USA.
Univ Calif Berkeley, Berkeley, CA 94720 USA.
RP CALTECH, Jet Prop Lab, Mail Stop 169-237,800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM djd@jord.jpl.nasa.gov
RI Penner, Joyce/J-1719-2012; Kahn, Ralph/D-5371-2012
OI Kahn, Ralph/0000-0002-5234-6359
NR 78
TC 14
Z9 14
U1 0
U2 2
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0003-0007
EI 1520-0477
J9 B AM METEOROL SOC
JI Bull. Amer. Meteorol. Soc.
PD OCT
PY 2004
VL 85
IS 10
BP 1523
EP 1533
DI 10.1175/BAMS-85-10-1523
PG 11
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 865GF
UT WOS:000224689900013
ER
PT J
AU Diner, DJ
Menzies, RT
Kahn, RA
Anderson, TL
Bosenberg, J
Charlson, RJ
Holben, BN
Hostetler, CA
Miller, MA
Ogren, JA
Stephens, GL
Torres, O
Wielicki, BA
Rasch, PJ
Travis, LD
Collins, WD
AF Diner, DJ
Menzies, RT
Kahn, RA
Anderson, TL
Bosenberg, J
Charlson, RJ
Holben, BN
Hostetler, CA
Miller, MA
Ogren, JA
Stephens, GL
Torres, O
Wielicki, BA
Rasch, PJ
Travis, LD
Collins, WD
TI Using the PARAGON framework to establish an accurate, consistent, and
cohesive long-term aerosol record
SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
LA English
DT Article
ID MICROPHYSICAL PARTICLE PARAMETERS; SPECTRAL-RESOLUTION LIDAR;
INDIAN-OCEAN EXPERIMENT; OPTICAL-SCATTERING PROPERTIES; SUN PHOTOMETER
MEASUREMENTS; IMAGING SPECTRORADIOMETER; TROPOSPHERIC AEROSOLS;
ATMOSPHERIC AEROSOLS; SATELLITE RETRIEVAL; PHASE FUNCTION
AB A comprehensive and cohesive aerosol measurement record with consistent, well-understood uncertainties is a prerequisite to understanding aerosol impacts on long-term climate and environmental variability. Objectives to attaining such an understanding include improving upon the current state-of-the-art sensor calibration and developing systematic validation methods for remotely sensed microphysical properties. While advances in active and passive remote sensors will lead to needed improvements in retrieval accuracies and capabilities, ongoing validation is essential so that the changing sensor characteristics do not mask atmospheric trends. Surface-based radiometer, chemical, and lidar networks have critical roles within an integrated observing system, yet they currently undersample key geographic regions, have limitations in certain measurement capabilities, and lack stable funding. In situ aircraft observations of size-resolved aerosol chemical composition are necessary to provide important linkages between active and passive remote sensing. A planned, systematic approach toward a global aerosol observing network, involving multiple sponsoring agencies and surface-based, suborbital, and spaceborne sensors, is required to prioritize trade-offs regarding capabilities and costs. This strategy is a key ingredient of the Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON) framework. A set of recommendations is presented.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Washington, Seattle, WA 98195 USA.
Max Planck Inst Meteorol, Hamburg, Germany.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
NASA, Langley Res Ctr, Hampton, VA 23665 USA.
Brookhaven Natl Lab, Upton, NY 11973 USA.
NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA.
Colorado State Univ, Ft Collins, CO 80523 USA.
Univ Maryland Baltimore Cty, Baltimore, MD 21228 USA.
Natl Ctr Atmospher Res, Boulder, CO 80307 USA.
NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
RP CALTECH, Jet Prop Lab, Mail Stop 169-237,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM djd@jord.jpl.nasa.gov
RI Kahn, Ralph/D-5371-2012; Collins, William/J-3147-2014; Torres,
Omar/G-4929-2013; Ogren, John/M-8255-2015
OI Kahn, Ralph/0000-0002-5234-6359; Collins, William/0000-0002-4463-9848;
Ogren, John/0000-0002-7895-9583
NR 76
TC 8
Z9 8
U1 0
U2 2
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0003-0007
EI 1520-0477
J9 B AM METEOROL SOC
JI Bull. Amer. Meteorol. Soc.
PD OCT
PY 2004
VL 85
IS 10
BP 1535
EP 1548
DI 10.1175/BAMS-85-10-1535
PG 14
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 865GF
UT WOS:000224689900014
ER
PT J
AU Thompson, AM
Witte, JC
Oltmans, SJ
Schmidlin, FJ
AF Thompson, AM
Witte, JC
Oltmans, SJ
Schmidlin, FJ
TI Shadoz - A tropical ozonesonde-radiosonde network for the atmospheric
community
SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
LA English
DT Article
ID QUASI-BIENNIAL OSCILLATION; MAPPING SPECTROMETER TOMS; GROUND-BASED
MEASUREMENTS; GTE TRACE-A; TROPOSPHERIC OZONE; SOUTHERN AFRICA;
STRATOSPHERIC AEROSOL; NORTHERN-HEMISPHERE; NITROGEN-DIOXIDE; SATELLITE
DATA
AB This article describes the Southern Hemisphere Additional Ozonesondes (SHADOZ) network of ozonesonde-radiosonde stations in the southern Tropics and subtropics. SHADOZ was initiated in 1998 by NASA, NOAA, and a team of international meteorological services and space agencies to remedy a paucity of ozone profile data in a region of intense natural variability and anthropogenic change. SHADOZ augments launches at selected sites and provides a public archive of ozonesonde and radiosonde data (see additional information online at http://croc.gsfc.nasa.gov/shadoz). Ozone is important because of its role as an atmospheric UV shield, surface pollutant, oxidant, and greenhouse gas. Ozone profile data are essential for the detection of ozone trends and for verification of satellite ozone retrievals. Instrumentation, data, and a summary of the first scientific findings from SHADOZ are presented. A zonal view shows that troposphere ozone accumulates over the south tropical Atlantic and adjacent continents throughout the year, consistent with large-scale atmospheric motion. At individual stations, week-to-week variations in tropospheric ozone profiles reflect episodic meteorology, for example, convection or advected pollution.
C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
SSAI, Lanham, MD USA.
NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA.
NASA, Wallops Flight Facil, Wallops Isl, VA 23337 USA.
RP NASA, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA.
EM thompson@gator1.gsfc.nasa.gov
RI Thompson, Anne /C-3649-2014
OI Thompson, Anne /0000-0002-7829-0920
NR 64
TC 16
Z9 16
U1 2
U2 4
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0003-0007
EI 1520-0477
J9 B AM METEOROL SOC
JI Bull. Amer. Meteorol. Soc.
PD OCT
PY 2004
VL 85
IS 10
BP 1549
EP +
DI 10.1175/BAMS-85-10-1549
PG 17
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 865GF
UT WOS:000224689900015
ER
PT J
AU Garay, MJ
Davies, R
Averill, C
Westphal, JA
AF Garay, MJ
Davies, R
Averill, C
Westphal, JA
TI Overlooked examples of cloud self-organization at the mesoscale
SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY
LA English
DT Article
ID MARINE STRATOCUMULUS; CONVECTION; MISR
AB Stratocumulus clouds are common in the tropical and subtropical marine boundary layer, and understanding these clouds is important due to their significant impact on the earth's radiation budget. Observations show that the marine boundary layer contains complex, but poorly understood processes, which, from time to time, result in the observable self-organization of cloud structures at scales ranging from a few to a few thousand kilometers. Such shallow convective cloud features, typically observed as hexagonal cells, are known generally as mesoscale cellular convection (MCC). Actinoform clouds are rarer, but visually more striking forms of MCC, which possess a radial structure.
Because mesoscale cloud features are typically too large to be observed from the ground, observations of hexagonal cells historically date only to the beginning of satellite meteorology. Examples of actinoform clouds were shown in the venerable "Picture of the Month" series in Monthly Weather Review in the early 1960s, but these clouds were generally forgotten as research focused on hexagonal cells.
Recent high-resolution satellite images have, in a sense, "rediscovered" actinoform clouds, and they appear to be much more prevalent than had been previously suspected. We show a number of examples of actinoform clouds from a variety of locations worldwide. In addition, we have conducted a detailed case study of an actinoform cloud system using data from the Multiangle Imaging SpectroRadiometer (MISR) and the Geostationary Operational Environmental Satellite (GOES), including analysis of cloud heights, radiative properties, and the time-evolution of the cloud system. We also examine earlier theories regarding actinoform clouds in light of the new satellite data.
C1 Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA.
CALTECH, Jet Prop Lab, Pasadena, CA USA.
Raytheon Corp, Informat Technol & Sci Serv, Pasadena, CA USA.
CALTECH, Dept Geol & Planetary Sci, Pasadena, CA 91125 USA.
RP Garay, MJ (reprint author), Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, 405 Hilgard Ave,Box 951565,7127 Math Sci Bldg, Los Angeles, CA 90095 USA.
EM garay@atmos.ucla.edu
RI Davies, Roger/D-4296-2009
OI Davies, Roger/0000-0002-2991-0409
NR 22
TC 13
Z9 13
U1 0
U2 5
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0003-0007
J9 B AM METEOROL SOC
JI Bull. Amer. Meteorol. Soc.
PD OCT
PY 2004
VL 85
IS 10
BP 1585
EP +
DI 10.1175/BAMS-85-10-1585
PG 11
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 865GF
UT WOS:000224689900017
ER
PT J
AU Grecu, M
Anagnostou, EN
AF Grecu, M
Anagnostou, EN
TI A differential attenuation based algorithm for estimating precipitation
from dual-wavelength spaceborne radar
SO CANADIAN JOURNAL OF REMOTE SENSING
LA English
DT Article
ID PASSIVE MICROWAVE OBSERVATIONS; PROFILING ALGORITHM; TRMM; RETRIEVAL
AB An algorithm for estimating precipitation from dual-wavelength spaceborne radar measurements is formulated and investigated. The algorithm is based on a single-wavelength attenuation-correction procedure applied within discrete ranges [r(1,)r(2)] along a radar ray, satisfying the condition r(1) - r(2) less than or equal to 750 m. The attenuation-correction procedure is based on two parameters, namely the integrated attenuation from the top of the atmosphere to r(1) and the intercept parameter (N-0(*)) of the normalized gamma drop size distribution model. The N-0* value is assumed constant within the discrete range. A cost function is defined to evaluate the discrepancy between the two-wavelength precipitation estimates obtained from the corrected reflectivity profile within the discrete range. Consequently, the path-integrated attenuation to r(1) and N-0(*) is determined through optimization, minimizing the cost function. The algorithm is investigated using synthetic data, i.e., derived from cloud model simulations, and airborne observations from the fourth convection and moisture experiment (CAMEX-4).
C1 Univ Connecticut, Dept Civil & Environm Engn, Storrs, CT 06269 USA.
Univ Maryland, Goddard Earth Sci & Technol Ctr, College Pk, MD 20742 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Anagnostou, EN (reprint author), Univ Connecticut, Dept Civil & Environm Engn, Storrs, CT 06269 USA.
EM manos@engr.uconn.edu
NR 14
TC 4
Z9 4
U1 0
U2 2
PU CANADIAN AERONAUTICS SPACE INST
PI OTTAWA
PA 1685 RUSSELL RD, UNIT 1-R, OTTAWA, ON K1G 0N1, CANADA
SN 0703-8992
J9 CAN J REMOTE SENS
JI Can. J. Remote Sens.
PD OCT
PY 2004
VL 30
IS 5
BP 697
EP 705
PG 9
WC Remote Sensing
SC Remote Sensing
GA 876EW
UT WOS:000225480100005
ER
PT J
AU White, MA
Nemani, RR
AF White, MA
Nemani, RR
TI Soil water forecasting in the continental United States: relative
forcing by meteorology versus leaf area index and the effects of
meteorological forecast errors
SO CANADIAN JOURNAL OF REMOTE SENSING
LA English
DT Article
ID FOREST ECOSYSTEM PROCESSES; DAILY SOLAR-RADIATION; REGIONAL
APPLICATIONS; RESOURCES MANAGEMENT; HYDROLOGIC BALANCE; CLIMATE
FORECASTS; COMPLEX TERRAIN; ATMOSPHERIC CO2; ENERGY-BALANCE;
GENERAL-MODEL
AB Forecasts of the states and fluxes of terrestrial ecosystems are an increasingly important tool for a large fire, famine, irrigation, energy, recreation, and agriculture community. A detailed understanding of the relative importance of vegetation phenology and meteorology, two of the main forcings of ecosystem forecasts, and the likely impact of errors in phenological and (or) meteorological forecasts are required prior to management implementation. Using the terrestrial observation and prediction system (TOPS) and 1982-1997 leaf area index (LAI) and meteorology for the conterminous United States, we tested the relative importance of interannual variability in meteorology and LAI for soil water simulations. In nearly all cases, meteorological variability influenced simulations far more than did LAI; the effects of ignoring realistic variability in either variable were most pronounced in arid, low-LAI regions. We then identified the critical meteorological forecast errors in temperature and precipitation that were required to generate statistically significant differences in 1-week soil water forecasts. Temperature critical errors approached 10 degreesC in winter but were only about 2-3 degreesC in summer. Precipitation critical errors were much more constant throughout the year and were usually less than 1 cm (error in weekly total precipitation).
C1 Utah State Univ, Dept Aquat Watershed & Earth Resources, Logan, UT 84322 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP White, MA (reprint author), Utah State Univ, Dept Aquat Watershed & Earth Resources, 5210 Old Main Hill, Logan, UT 84322 USA.
EM mikew@cc.usu.edu
OI White, Michael/0000-0002-0238-8913
NR 55
TC 10
Z9 10
U1 0
U2 6
PU CANADIAN AERONAUTICS SPACE INST
PI OTTAWA
PA 1685 RUSSELL RD, UNIT 1-R, OTTAWA, ON K1G 0N1, CANADA
SN 0703-8992
J9 CAN J REMOTE SENS
JI Can. J. Remote Sens.
PD OCT
PY 2004
VL 30
IS 5
BP 717
EP 730
PG 14
WC Remote Sensing
SC Remote Sensing
GA 876EW
UT WOS:000225480100007
ER
PT J
AU Moran, MS
Peters-Lidard, CD
Watts, JM
McElroy, S
AF Moran, MS
Peters-Lidard, CD
Watts, JM
McElroy, S
TI Estimating soil moisture at the watershed scale with satellite-based
radar and land surface models
SO CANADIAN JOURNAL OF REMOTE SENSING
LA English
DT Review
ID HYDROLOGIC DATA ASSIMILATION; VARIATIONAL DATA ASSIMILATION; ENERGY
BALANCE COMPONENTS; SPATIALLY-VARIABLE WATER; INTEGRAL-EQUATION MODEL;
SIMPLE BIOSPHERE MODEL; NEAR-SURFACE; PARAMETERIZATION SCHEMES; SAR
DATA; NORMALIZED DIFFERENCE
AB Spatially distributed soil moisture profiles are required for watershed applications such as drought and flood prediction, crop irrigation scheduling, pest management, and determining mobility with lightweight vehicles. Satellite-based soil moisture can be obtained from passive microwave, active microwave, and optical sensors, although the coarse spatial resolution of passive microwave and the inability to obtain vertically resolved information from optical sensors limit their usefulness for watershed-scale applications. Active microwave sensors such as synthetic aperture radar (SAR) currently represent the best approach for obtaining spatially distributed surface soil moisture at scales of 10-100 in for watersheds ranging from 1 000 to 25 000 km(2). Although SAR provides surface soil moisture, the applications listed above require vertically resolved soil moisture profiles. To obtain distributed soil moisture profiles, a combined approach of calibration and data assimilation in soil vegetation atmosphere transfer (SVAT) models based on recent advances in soil physics is the most promising avenue of research. This review summarizes the state of the science using current satellite-based sensors to determine watershed-scale surface soil moisture distribution and the state of combining SVAT models with data assimilation and calibration approaches for the estimation of profile soil moisture. The basic conclusion of this review is that currently orbiting SAR sensors combined with available SVAT models could provide distributed profile soil moisture information with known accuracy at the watershed scale. The priority areas for future research should include image-based approaches for mapping surface roughness, determination of soil moisture in densely vegetated sites, active and passive microwave data fusion, and joint calibration and data assimilation approaches for a combined remote sensing - modeling system. For validation, a worldwide in situ soil moisture monitoring program should be implemented. Finally, to realize the full potential of satellite-based soil moisture estimation for watershed applications, it will be necessary to continue sensor development, improve image availability and timely delivery, and reduce image cost.
C1 USDA, ARS, SW Watershed Res Ctr, Tucson, AZ 85719 USA.
NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA.
US Army Engineer Res & Dev Ctr, Topog Engn Ctr, Alexandria, VA 22315 USA.
RP Moran, MS (reprint author), USDA, ARS, SW Watershed Res Ctr, Tucson, AZ 85719 USA.
EM smoran@tucson.ars.ag.gov
RI Peters-Lidard, Christa/E-1429-2012
OI Peters-Lidard, Christa/0000-0003-1255-2876
NR 179
TC 130
Z9 134
U1 6
U2 55
PU CANADIAN AERONAUTICS & SPACE INST
PI KANATA
PA 350 TERRY FOX DR, STE 104, KANATA, ON K2K 2W5, CANADA
SN 0703-8992
EI 1712-7971
J9 CAN J REMOTE SENS
JI Can. J. Remote Sens.
PD OCT
PY 2004
VL 30
IS 5
BP 805
EP 826
PG 22
WC Remote Sensing
SC Remote Sensing
GA 876EW
UT WOS:000225480100014
ER
PT J
AU Madden, MEE
Horz, F
Bodnar, RJ
AF Madden, MEE
Horz, F
Bodnar, RJ
TI Experimental simulation of shock-induced re-equilibration of fluid
inclusions
SO CANADIAN MINERALOGIST
LA English
DT Article; Proceedings Paper
CT 8th Biennial Meeting of the Pan-American Conference on Research on Fluid
Inclusions
CY JUL 07-11, 2002
CL Halifax, CANADA
SP Mineralog Assoc Canada, St Francis Xavier Univ, Nova Scotia Dept Natl Resources, Petroleum Res Atlantic Canada
DE fluid inclusions; quartz; re-equilibration; experimental impacts; shock
metamorphism; meteorites
ID CONFINING PRESSURE; MARTIAN METEORITES; NATURAL QUARTZ; MONAHANS 1998;
METAMORPHISM; REEQUILIBRATION; CHONDRITES; SHERGOTTY; ASSEMBLAGES;
CHASSIGNY
AB Meteorite impacts and their attendant shock waves create conditions of extremely high strain-rates, temperatures, and pressures. As the role of fluids in our Solar System becomes increasingly recognized and studied, it is important to understand the effects of shock on fluid-bearing materials. In this study, the effects of 5-30 GPa experimental shock waves on aqueous fluid inclusions in single-crystal quartz were observed and quantified. The homogenization temperatures of fluid inclusions within the samples and other physical features were documented before and after the experimental shock events. The properties of fluid inclusions show a systematic and gradual evolution with increasing shock pressure. Some fluid inclusions survive shock pressures of 6 GPa, yet they exhibit an increase in homogenization temperature relative to pre-impact measurements, suggesting that re-equilibration occurred because of internal overpressures. Decrepitated fluid inclusions were observed in the 6 and 7.6 GPa samples, whereas textures indicative of the collapse of fluid inclusions due to internal underpressure were observed in samples shocked at 7.6-12 GPa. No features that could be directly related to fluid inclusions were observed in samples shocked at pressures greater than 12 GPa. Results of these experiments suggest that fluid inclusions initially undergo a decrease in volume during shock compression. If the fluid inclusions survive this event, the initial decrease in volume is overprinted by the subsequent effects of elevated temperature at ambient pressure, leading to an increase in inclusion volume and homogenization temperature. Therefore, homogenization temperatures of fluid inclusions found in shocked materials should be considered a maximum value, as the density of the originally trapped fluid was likely greater than that observed in shock-processed inclusions. These results suggest that the rarity of fluid inclusions in meteorites may be a result of shock processing, and may not reflect a fluid-poor environment on the parent body.
C1 Virginia Polytech Inst & State Univ, Dept Geosci, Blacksburg, VA 24061 USA.
NASA, Lyndon B Johnson Space Ctr, Astromat Res Off, Houston, TX 77058 USA.
RP Madden, MEE (reprint author), Virginia Polytech Inst & State Univ, Dept Geosci, 4044 Derring Hall, Blacksburg, VA 24061 USA.
EM melwood@vt.edu; rjb@vt.edu
RI Bodnar, Robert/A-1916-2009; Elwood Madden, Megan/C-3381-2009
NR 46
TC 7
Z9 7
U1 0
U2 4
PU MINERALOGICAL ASSOC CANADA
PI OTTAWA
PA PO BOX 78087, MERILINE POSTAL OUTLET, 1460 MERIVALE RD, OTTAWA, ONTARIO
K2E 1B1, CANADA
SN 0008-4476
J9 CAN MINERAL
JI Can. Mineral.
PD OCT
PY 2004
VL 42
BP 1357
EP 1368
DI 10.2113/gscanmin.42.5.1357
PN 5
PG 12
WC Mineralogy
SC Mineralogy
GA 877FP
UT WOS:000225553500006
ER
PT J
AU Kojima, J
Nguyen, QV
AF Kojima, J
Nguyen, QV
TI Entangled biphoton virtual-state spectroscopy of the A(2)Sigma(+)-X-2 pi
system of OH
SO CHEMICAL PHYSICS LETTERS
LA English
DT Article
ID PARAMETRIC DOWN-CONVERSION; COHERENCE PROPERTIES; DATABASE
AB This Letter describes the first application of entanglement-induced virtual-state spectroscopy to a molecular system. Non-classical, non-monotonic behaviour in the two-photon absorption cross-section of the OH A-X system, induced by entangled photon pairs is theoretically demonstrated. A Fourier transform analysis of the biphoton cross-section permits access to the energy eigenvalues of intermediate rovibronic states with a fixed excitation energy. Our analysis reveals that the implementation of virtual-state spectroscopy of the OH A-X system requires tuning of the relative path delay tau(e) over a picosecond range with ferntosecond resolution for a certain entanglement time T-e. (C) 2004 Elsevier B.V. All rights reserved.
C1 NASA, John H Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA.
RP Kojima, J (reprint author), Ohio Aerosp Inst, 22800 Cedar Point Rd, Cleveland, OH 44142 USA.
EM Jun.Kojima@grc.nasa.gov; Quang-Viet.Nguyen@nasa.gov
NR 17
TC 9
Z9 9
U1 1
U2 4
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0009-2614
J9 CHEM PHYS LETT
JI Chem. Phys. Lett.
PD OCT 1
PY 2004
VL 396
IS 4-6
BP 323
EP 328
DI 10.1016/j.cplett.2004.08.051
PG 6
WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical
SC Chemistry; Physics
GA 858KN
UT WOS:000224190800018
ER
PT J
AU Koehne, JE
Chen, H
Cassell, AM
Yi, Q
Han, J
Meyyappan, M
Li, J
AF Koehne, JE
Chen, H
Cassell, AM
Yi, Q
Han, J
Meyyappan, M
Li, J
TI Miniaturized multiplex label-free electronic chip for rapid nucleic acid
analysis based on carbon nanotube nanoelectrode arrays
SO CLINICAL CHEMISTRY
LA English
DT Article
ID MOLECULAR DIAGNOSTICS; DNA; BIOSENSORS
AB Background: Reducing cost and time is the major concern in clinical diagnostics, particularly in molecular diagnostics. Miniaturization technologies have been recognized as promising solutions to provide low-cost microchips for diagnostics. With the recent advancement in nanotechnologies, it is possible to further improve detection sensitivity and simplify sample preparation by incorporating nanoscale elements in diagnostics devices. A fusion of micro- and nanotechnologies with biology has great potential for the development of low-cost disposable chips for rapid molecular analysis that can be carried out with simple handheld devices.
Approach: Vertically aligned multiwalled carbon nanotubes (MWNTs) are fabricated on predeposited microelectrode pads and encapsulated in SiO2 dielectrics with only the very end exposed at the surface to form an inlaid nanoelectrode array (NEA). The NEA is used to collect the electrochemical signal associated with the target molecules binding to the probe molecules, which are covalently attached to the end of the MWNTs.
Content. A 3 X 3 microelectrode array is presented to demonstrate the miniaturization and multiplexing capability. A randomly distributed MWNT NEA is fabricated on each microelectrode pad. Selective functionalization of the MWNT end with a specific oligortucleotide probe and passivation of the SiO2 surface with ethylene glycol moieties are discussed. Ru(bpy)(2+)-mediator-amplified guanine oxidation is used to directly measure the electrochemical signal associated with target molecules.
Summary: The discussed MWNT NEAs have ultrahigh sensitivity in direct electrochemical detection of guanine bases in the nucleic acid target. Fewer than similar to1000 target nucleic acid molecules can be measured with a single microelectrode pad of similar to20 X 20 mum(2), which approaches the detection limit of laser scanners in fluorescence-based DNA microarray techniques. MWNT NEAs can be easily integrated with microelectronic circuitry and microfluidics for development of a fully automated system for rapid molecular analysis with minimum cost. (C) 2004 American Association for Clinical Chemistry.
C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA.
RP Li, J (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA.
EM jli@mail.arc.nasa.gov
RI Li, Jun/H-7771-2013
OI Li, Jun/0000-0002-3689-8946
NR 28
TC 74
Z9 76
U1 0
U2 15
PU AMER ASSOC CLINICAL CHEMISTRY
PI WASHINGTON
PA 2101 L STREET NW, SUITE 202, WASHINGTON, DC 20037-1526 USA
SN 0009-9147
EI 1530-8561
J9 CLIN CHEM
JI Clin. Chem.
PD OCT
PY 2004
VL 50
IS 10
BP 1886
EP 1893
DI 10.1373/clinchem.2004.036285
PG 8
WC Medical Laboratory Technology
SC Medical Laboratory Technology
GA 857MB
UT WOS:000224119800038
PM 15319319
ER
PT J
AU Hermanson, JC
Johari, H
Stocker, DP
Hegde, UG
AF Hermanson, JC
Johari, H
Stocker, DP
Hegde, UG
TI Buoyancy effects in strongly pulsed turbulent diffusion flames
SO COMBUSTION AND FLAME
LA English
DT Article
DE microgravity; turbulence; nonpremixed flames
ID HEAT RELEASE; ENTRAINMENT; JETS; TEMPERATURE; LENGTH; SCALE; PUFFS
AB The effects of buoyancy in pulsed turbulent jet diffusion flames were investigated by conducting experiments in both microgravity and normal gravity. In all cases the flames were fully modulated; that is, the fuel flow was completely shut off between pulses. Unheated ethylene fuel was injected using a 2-mm-diameter nozzle into a combustor with an oxidizer coflow at ambient pressure. Microgravity conditions (10(-4) g) were achieved for 2.2 s in drop tower tests. Flames with short injection times and high duty cycle exhibit a marked increase in the ensemble-averaged flame length due to the removal of buoyancy. For other injection conditions, including steady state injection, the flame length is not strongly impacted by buoyancy. The significant increases in flame length with injection duty cycle are consistent with the duty cycle near the flame tip of microgravity flames exceeding that of normal gravity flames. The celerity of isolated compact flame puffs is approximately 40% less in microgravity than in normal gravity. An analytical argument indicates that duty cycle near the flame tip can significantly exceed that at injection due to the combination of a puff growth and the decrease in the celerity of the flame puffs with downstream distance. This effect is predicted to be significantly greater in the absence of buoyancy and for shorter injection times, in qualitative agreement with the experiments. The cycle-averaged centerline temperatures were generally higher in the microgravity flames than in normal gravity, especially at the flame tip where the difference was as much as 200 K. (C) 2004 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
C1 Univ Washington, Dept Aeronaut & Astronaut, Seattle, WA 98195 USA.
Worcester Polytech Inst, Dept Mech Engn, Worcester, MA 01609 USA.
NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Hermanson, JC (reprint author), Univ Washington, Dept Aeronaut & Astronaut, Seattle, WA 98195 USA.
EM jherm@aa.washington.edu
NR 39
TC 12
Z9 12
U1 0
U2 4
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0010-2180
J9 COMBUST FLAME
JI Combust. Flame
PD OCT
PY 2004
VL 139
IS 1-2
BP 61
EP 76
DI 10.1016/j.combustflame.2004.08.005
PG 16
WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary;
Engineering, Chemical; Engineering, Mechanical
SC Thermodynamics; Energy & Fuels; Engineering
GA 865QU
UT WOS:000224718400006
ER
PT J
AU Sullivan, DG
Shaw, JN
Mask, PL
Rickman, D
Luvall, J
Wersinger, JM
AF Sullivan, DG
Shaw, JN
Mask, PL
Rickman, D
Luvall, J
Wersinger, JM
TI Evaluating corn nitrogen variability via remote-sensed data
SO COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS
LA English
DT Article
DE remote sensing; corn; yield; nitrogen management; multispectral
ID REFLECTANCE CHARACTERISTICS; GRAIN-YIELD; LEAVES; IMAGERY; GROWTH
AB Transformations and losses of nitrogen (N) throughout the growing season can be costly. Methods in place to improve N management and to facilitate split N applications during the growing season can be time consuming and logistically difficult. Remote sensing (RS) may be a method to rapidly assess temporal changes in crop N status and to promote more efficient N management. This study was designed to evaluate the ability of three different RS platforms to predict N variability in corn (Zea mays L.) leaves during vegetative and early reproductive growth stages. Plots (15 x 15 m) were established in the Coastal Plain (CP) and in the Appalachian Plateau (AP) physiographic regions each spring from 2000 to 2002 in a completely randomized design. Treatments consisted of four N rates (0, 56, 112, and 168 kg N ha(-1)) applied as ammonium nitrate (NH4NO3) replicated four times. Spectral measurements were acquired via spectroradiometer (lambda = 350-1050 nm), Airborne Terrestrial Applications Sensor (ATLAS) ( lambda= 400-12,500 nm), and the IKONOS satellite (lambda =450-900nm). Spectroradiometer data were collected on a biweekly basis from V4 through R1. Due to the nature of satellite and aircraft acquisitions, these data were acquired per availability. Chlorophyll meter (SPAD) and tissue N were collected as ancillary data, along with each RS acquisition. Results showed vegetation indices derived from hand-held spectroradiometer measurements as early as V6-V8 were linearly related to yield and tissue N concentration. The ATLAS data were correlated with tissue N at the AP site during the V6 stage (r(2) =0.66), but no significant relationships were observed at the CP site. No significant relationships were observed between plant N and IKONOS imagery. By using a combination of the greenness vegetation index and the normalized difference vegetation index, RS data acquired via ATLAS and the spectroradiometer could be used to evaluate tissue N variability and to estimate corn yield variability given ideal growing conditions.
C1 Auburn Univ, Allison Lab 302, Auburn, AL 36849 USA.
NASA, George C Marshall Space Flight Ctr, NSSTC, Global Hydrol & Climate Ctr, Huntsville, AL 35812 USA.
RP Sullivan, DG (reprint author), USDA ARS, SE Watershed Res Lab, POB 946, Tifton, GA 31794 USA.
EM dgs@tifton.usda.gov
OI Rickman, Doug/0000-0003-3409-2882
NR 25
TC 4
Z9 6
U1 0
U2 3
PU MARCEL DEKKER INC
PI NEW YORK
PA 270 MADISON AVE, NEW YORK, NY 10016 USA
SN 0010-3624
J9 COMMUN SOIL SCI PLAN
JI Commun. Soil Sci. Plant Anal.
PD OCT
PY 2004
VL 35
IS 17-18
BP 2465
EP 2483
DI 10.1081/LCSS-200030339
PG 19
WC Agronomy; Plant Sciences; Chemistry, Analytical; Soil Science
SC Agriculture; Plant Sciences; Chemistry
GA 866AA
UT WOS:000224744100006
ER
PT J
AU Trombulak, SC
Omland, KS
Robinson, JA
Lusk, JJ
Fleischner, TL
Brown, G
Domroese, M
AF Trombulak, SC
Omland, KS
Robinson, JA
Lusk, JJ
Fleischner, TL
Brown, G
Domroese, M
TI Principles of conservation biology: Recommended guidelines for
conservation literacy from the Education Committee of the Society for
Conservation Biology
SO CONSERVATION BIOLOGY
LA English
DT Editorial Material
ID SCIENCE; VALUES
C1 Middlebury Coll, Dept Biol, Middlebury, VT 05753 USA.
Middlebury Coll, Environm Studies Program, Middlebury, VT 05753 USA.
Univ Vermont, Rubenstein Sch Environm & Nat Resources, Vermont Cooperat Fish & Wildlife Res Unit, Burlington, VT 05405 USA.
NASA, Lyndon B Johnson Space Ctr, Earth Sci & Image Anal Lab, Houston, TX 77058 USA.
Oklahoma State Univ, Dept Forestry, Stillwater, OK 74078 USA.
Prescott Coll, Environm Studies Program, Prescott, AZ 86301 USA.
Capilano Coll, Environm Sci & Management Program, N Vancouver, BC V7J 3H5, Canada.
Amer Museum Nat Hist, Ctr Biodivers & Conservat, New York, NY 10024 USA.
RP Trombulak, SC (reprint author), Middlebury Coll, Dept Biol, Middlebury, VT 05753 USA.
EM trombulak@middlebury.edu
OI Robinson, Julie/0000-0002-6832-6459
NR 26
TC 42
Z9 48
U1 1
U2 23
PU BLACKWELL PUBLISHING INC
PI MALDEN
PA 350 MAIN ST, MALDEN, MA 02148 USA
SN 0888-8892
J9 CONSERV BIOL
JI Conserv. Biol.
PD OCT
PY 2004
VL 18
IS 5
BP 1180
EP 1190
DI 10.1111/j.1523-1739.2004.01851.x
PG 11
WC Biodiversity Conservation; Ecology; Environmental Sciences
SC Biodiversity & Conservation; Environmental Sciences & Ecology
GA 856UX
UT WOS:000224071800004
ER
PT J
AU Doran, PT
Clifford, SM
Forman, SL
Nyquist, L
Papanastassiou, DA
Stewart, BW
Sturchio, NC
Swindle, TD
Cerling, T
Kargel, J
McDonald, G
Nishiizumi, K
Poreda, R
Rice, JW
Tanaka, K
AF Doran, PT
Clifford, SM
Forman, SL
Nyquist, L
Papanastassiou, DA
Stewart, BW
Sturchio, NC
Swindle, TD
Cerling, T
Kargel, J
McDonald, G
Nishiizumi, K
Poreda, R
Rice, JW
Tanaka, K
TI Mars chronology: assessing techniques for quantifying surficial
processes
SO EARTH-SCIENCE REVIEWS
LA English
DT Review
DE Mars; chronology; surficial processes; dating
ID THERMAL EMISSION SPECTROMETER; MARTIAN NORTHERN PLAINS; ISOTOPIC
COMPOSITION; LAYERED DEPOSITS; NEUTRON-CAPTURE; ANCIENT OCEANS; THARSIS
REGION; CORE FORMATION; SOLAR-SYSTEM; ICE CORE
AB Currently, the absolute chronology of Martian rocks, deposits and events is based mainly on crater counting and remains highly imprecise with epoch boundary uncertainties in excess of 2 billion years. Answers to key questions concerning the comparative origin and evolution of Mars and Earth will not be forthcoming without a rigid Martian chronology, enabling the construction of a time scale comparable to Earth's. Priorities for exploration include calibration of the cratering rate, dating major volcanic and fluvial events and establishing chronology of the polar layered deposits. If extinct and/or extant life is discovered, the chronology of the biosphere will be of paramount importance. Many radiometric and cosmogenic techniques applicable on Earth and the Moon will apply to Mars after certain baselines (e.g. composition of the atmosphere, trace species, chemical and physical characteristics of Martian dust) are established. The high radiation regime may pose a problem for dosimetry-based techniques (e.g. luminescence). The unique isotopic composition of nitrogen in the Martian atmosphere may permit a Mars-specific chronometer for tracing the time-evolution of the atmosphere and of lithic phases with trapped atmospheric gases. Other Mars-specific chronometers include measurement of gas fluxes and accumulation of platinum group elements (PGE) in the regolith. Putting collected samples into geologic context is deemed essential, as is using multiple techniques on multiple samples. If in situ measurements are restricted to a single technique it must be shown to give consistent results on multiple samples, but in all cases, using two or more techniques (e.g. on the same lander) will reduce error. While there is no question that returned samples will yield the best ages, in situ techniques have the potential to be flown on multiple missions providing a larger data set and broader context in which to place the more accurate dates. (C) 2004 Elsevier B.V. All rights reserved.
C1 Univ Illinois, Dept Earth & Environm Sci, Chicago, IL 60607 USA.
Lunar & Planetary Inst, Houston, TX 77058 USA.
NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA.
Univ Pittsburgh, Dept Geol & Planetary Sci, Pittsburgh, PA 15260 USA.
Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
Univ Utah, Dept Geol & Geophys, Salt Lake City, UT 84112 USA.
US Geol Survey, Flagstaff, AZ 86001 USA.
Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
Univ Rochester, Dept Environm Sci, Rochester, NY USA.
Arizona State Univ, Dept Geol Sci, Tempe, AZ USA.
RP Doran, PT (reprint author), Univ Illinois, Dept Earth & Environm Sci, Chicago, IL 60607 USA.
EM pdoran@uic.edu
NR 111
TC 27
Z9 28
U1 4
U2 11
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0012-8252
J9 EARTH-SCI REV
JI Earth-Sci. Rev.
PD OCT
PY 2004
VL 67
IS 3-4
BP 313
EP 337
DI 10.1016/j.earscirev.2004.04.001
PG 25
WC Geosciences, Multidisciplinary
SC Geology
GA 897WP
UT WOS:000227037000004
ER
PT J
AU Myung, NV
Park, DY
Urgiles, DE
George, T
AF Myung, NV
Park, DY
Urgiles, DE
George, T
TI Electroformed iron and FeCo alloy
SO ELECTROCHIMICA ACTA
LA English
DT Article
DE electroforming; soft magnetic thin film; CoFe electrodeposit; Fe
electrodeposits; low-stress
ID THIN-FILM ALLOYS; ELECTRODEPOSITION; MICROSTRUCTURES; SOFT
AB Iron and FeCo alloys were electroformed from additive-free acidic chloride baths. Film stress and magnetic properties were strongly influenced by deposition current density and operating temperature. In general, low film stress and low coercivity (H-C) was achieved with low current density and high operating temperature baths. SEM micrographs indicated that these conditions promote large grain growth. Coercivity of electroformed iron films linearly increased with increasing film stress, indicating that magnetoelastic energy is a dominant anisotropy. The addition of 0.25 M CaCl2 improves current efficiency while maintaining low film stress. The lowest iron film stress of 5 MPa was achieved from 1.5 M FeCl2 in the absence of CaCl2 at 20 mA cm(-2) with a current efficiency of 91%. A "normal" codeposition of FeCo was observed in acidic chloride baths, where the deposition rate of Co2+ was faster than Fe2+. Film compositions also played an important role in magnetic properties of FeCo films in addition to film stress. Magnetic saturation (M-S) of FeCo films increased linearly with an increase in deposited Fe content. High magnetic saturation with low-stress (M-S of 2.3 T and sigma = 70 MPa) were achieved from 7 1 Fe29Co films. (C) 2004 Elsevier Ltd. All rights reserved.
C1 Univ Calif Riverside, Dept Chem & Environm Engn, Riverside, CA 92521 USA.
Hanbat Natl Univ, Dept Appl Mat Engn, Taejon 305719, South Korea.
CALTECH, Jet Prop Lab, MEMS Technol Grp, Pasadena, CA 91109 USA.
RP Myung, NV (reprint author), Univ Calif Riverside, Dept Chem & Environm Engn, Riverside, CA 92521 USA.
EM myung@engr.ucr.edu
NR 29
TC 25
Z9 27
U1 2
U2 17
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0013-4686
J9 ELECTROCHIM ACTA
JI Electrochim. Acta
PD OCT 1
PY 2004
VL 49
IS 25
BP 4397
EP 4404
DI 10.1016/j.electacta.2004.04.031
PG 8
WC Electrochemistry
SC Electrochemistry
GA 843UY
UT WOS:000223113300017
ER
PT J
AU Driggers, WB
Carlson, JK
Cullum, B
Dean, JM
Oakley, D
Ulrich, G
AF Driggers, WB
Carlson, JK
Cullum, B
Dean, JM
Oakley, D
Ulrich, G
TI Age and growth of the blacknose shark, Carcharhinus acronotus, in the
western North Atlantic Ocean with comments on regional variation in
growth rates
SO ENVIRONMENTAL BIOLOGY OF FISHES
LA English
DT Article
DE life history; Carcharhinidae; small coastal shark; elasmobranch
ID GULF-OF-MEXICO; RHIZOPRIONODON-TERRAENOVAE; NORTHWESTERN GULF;
BONNETHEAD SHARK; SHARPNOSE SHARK; SPHYRNA-TIBURO; SPINY DOGFISH;
SANDBAR SHARK; LIFE-HISTORY; SOUTH-AFRICA
AB We examined the age and growth of the blacknose shark, Carcharhinus acronotus, in the western North Atlantic Ocean by obtaining direct age estimates using vertebral centra. We verified annual deposition of growth increments with marginal increment analysis and validated it by analyzing vertebrae marked with oxytetracycline from a female blacknose shark held in captivity. Von Bertalanffy growth parameters indicated that female blacknose sharks have a lower growth constant (k), a larger theortical maximum size (L-infinity), and are longer lived than males. We compared these growth parameters for blacknose sharks in the western North Atlantic Ocean to growth parameters for blacknose sharks collected in the eastern Gulf of Mexico to test for di.ffrences between regions. Females in the western North Atlantic Ocean have a significantly lower L 1, lower k, and a higher theoretical longevity than females in the Gulf of Mexico. Males in the western North Atlantic Ocean have a higher L-infinity, lower k, and higher theoretical longevity than males in the Gulf of Mexico. The significant differences between these life history parameters for blacknose sharks suggest that, when possible, future management initiatives concerning blacknose sharks should consider managing the populations in the western North Atlantic and the Gulf of Mexico as separate stocks.
C1 Univ S Carolina, Belle W Baruch Inst Marine Biol & Coastal Res, Columbia, SC 29208 USA.
Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Panama City Lab, Panama City, FL 32408 USA.
S Carolina Dept Nat Resources, Marine Resources Div, Charleston, SC 29412 USA.
RP Driggers, WB (reprint author), Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Mississippi Labs, PO Drawer 1207, Pascagoula, MS 39568 USA.
EM William.Driggers@noaa.gov
NR 28
TC 29
Z9 31
U1 0
U2 9
PU KLUWER ACADEMIC PUBL
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0378-1909
J9 ENVIRON BIOL FISH
JI Environ. Biol. Fishes
PD OCT
PY 2004
VL 71
IS 2
BP 171
EP 178
DI 10.1007/s10641-004-0105-z
PG 8
WC Ecology; Marine & Freshwater Biology
SC Environmental Sciences & Ecology; Marine & Freshwater Biology
GA 865KP
UT WOS:000224701900008
ER
PT J
AU Stehlik, LL
Pikanowski, RA
McMillan, DG
AF Stehlik, LL
Pikanowski, RA
McMillan, DG
TI The Hudson-Raritan Estuary as a crossroads for distribution of blue
(Callinectes sapidus), lady (Ovalipes ocellatus), and Atlantic rock
(Cancer irroratus) crabs
SO FISHERY BULLETIN
LA English
DT Article
ID LOWER CHESAPEAKE BAY; PREY SIZE-SELECTION; SOUTHERN NEW-JERSEY;
TIDAL-MARSH CREEK; NEW-YORK BIGHT; FEEDING-HABITS; POPULATION-DYNAMICS;
NICHE SEGREGATION; BRACHYURAN CRABS; NATURAL DIET
AB Blue (Callinectes sapidus) (Portunidae), lady (Ovalipes ocellatus) (Portunidae), and Atlantic rock (Cancer irroratus) (Cancridae) crabs inhabit estuaries on the northeast United States coast for parts or all of their life cycles. Their distributions overlap or cross during certain seasons. During a 1991-94 monthly otter trawl survey in the Hudson-Raritan Estuary between New York and New Jersey, blue and lady crabs were collected in warmer months and Atlantic rock crabs in colder months. Sex ratios, male: female, of mature crabs were 1:2.0 for blue crabs, 1:3.1 for lady crabs, and 21.4:1 for Atlantic rock crabs. Crabs, 1286 in total, were sub-sampled for dietary analysis, and the dominant prey taxa for all crabs, by volume of foregut contents, were mollusks and crustaceans. The proportion of amphipods and shrimp in diets decreased as crab size increased. Trophic niche breadth was widest for blue crabs, narrower for lady crabs, and narrowest for Atlantic rock crabs. Trophic overlap was lowest between lady crabs and Atlantic rock crabs, mainly because of frequent consumption of the dwarf surfclam (Mulinia lateralis) by the former and the blue mussel (Mytilus edulis) by the latter. The result of cluster analysis showed that size class and location of capture of predators in the estuary were more influential on diet than the species or sex of the predators.
C1 NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, James J Howard Marine Sci Lab, Highlands, NJ 07732 USA.
RP Stehlik, LL (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, James J Howard Marine Sci Lab, 74 Magruder Rd, Highlands, NJ 07732 USA.
EM Linda.Stehlik@noaa.gov
NR 71
TC 7
Z9 7
U1 1
U2 10
PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE
PI SEATTLE
PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA
SN 0090-0656
J9 FISH B-NOAA
JI Fish. Bull.
PD OCT
PY 2004
VL 102
IS 4
BP 693
EP 710
PG 18
WC Fisheries
SC Fisheries
GA 865SV
UT WOS:000224724000011
ER
PT J
AU Kerstetter, DW
Polovina, JJ
Graves, JE
AF Kerstetter, DW
Polovina, JJ
Graves, JE
TI Evidence of shark predation and scavenging on fishes equipped with
pop-up satellite archival tags
SO FISHERY BULLETIN
LA English
DT Article
ID MARLIN MAKAIRA-NIGRICANS; CARCHARODON-CARCHARIAS; WHITE SHARKS;
MOVEMENTS; SURVIVAL; TEMPERATURE; TELEMETRY; BEHAVIOR; DEPTH
C1 Virginia Inst Marine Sci, Coll William & Mary, Sch Marine Sci, Gloucester Point, VA 23062 USA.
Natl Marine Fisheries Serv, Pacific Isl Fisheries Sci Ctr, Honolulu, HI 96822 USA.
RP Kerstetter, DW (reprint author), Virginia Inst Marine Sci, Coll William & Mary, Sch Marine Sci, Gloucester Point, VA 23062 USA.
EM bailey@vims.edu
NR 20
TC 31
Z9 31
U1 1
U2 10
PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE
PI SEATTLE
PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA
SN 0090-0656
J9 FISH B-NOAA
JI Fish. Bull.
PD OCT
PY 2004
VL 102
IS 4
BP 750
EP 756
PG 7
WC Fisheries
SC Fisheries
GA 865SV
UT WOS:000224724000016
ER
PT J
AU Hoehler, TM
AF Hoehler, T. M.
TI Biological energy requirements as quantitative boundary conditions for
life in the subsurface
SO GEOBIOLOGY
LA English
DT Article
AB All life requires energy, which must be extracted from the environment. For all known life, free energy must be available at finite minimum levels in order to be usefully harnessed and must be delivered at finite minimum rates in order to support basic biochemical integrity and function. While seldom tested in the high energy light- and oxygen-based metabolisms of the surface biosphere, the magnitude of these requirements-the biological energy quantum (BEQ) and maintenance energy (ME) requirements, respectively-is considerable with respect to the potential metabolisms and energy sources that characterize the deep subsurface realm. As such, they constitute a fundamental constraint on the possible nature, distribution, and activity of microbial life in that environment. Because the energy released in a chemical transformation can be equated to the concentrations of substrates and products, both the BEQ and ME requirements define the minimum substrate concentration and minimum substrate production rate that must be sustained by a given environment for it to be capable of supporting life. The magnitudes of the BEQ and ME requirements are sensitive to a range of environmental parameters that may vary significantly in the subsurface. Temperature exerts a particularly strong control and is among the most important parameters to be considered in evaluating the energetic habitability of subsurface environments.
C1 NASA, Exobiol Branch, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Hoehler, TM (reprint author), NASA, Exobiol Branch, Ames Res Ctr, Moffett Field, CA 94035 USA.
EM tori.m.hoehler@nasa.gov
FU NASA
FX I am grateful to Marc Alperin for providing extensive discussions on
microbial energy requirements and diffusion in spherical coordinates.
Tom McCollom kindly provided the mineral- water equilibrium
H2 activity calculations and useful discussions concerning
energy availability and liberation in mineral systems. This work was
supported by the NASA exobiology program and the NASA Astrobiology
Institute.
NR 71
TC 81
Z9 84
U1 0
U2 48
PU WILEY-BLACKWELL PUBLISHING, INC
PI MALDEN
PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA
SN 1472-4677
J9 GEOBIOLOGY
JI Geobiology
PD OCT
PY 2004
VL 2
IS 4
BP 205
EP 215
DI 10.1111/j.1472-4677.2004.00033.x
PG 11
WC Biology; Environmental Sciences; Geosciences, Multidisciplinary
SC Life Sciences & Biomedicine - Other Topics; Environmental Sciences &
Ecology; Geology
GA V06CL
UT WOS:000207171600002
ER
PT J
AU Croskey, CL
Mitchell, JD
Goldberg, RA
Blix, TA
Rapp, M
Latteck, R
Friedrich, M
Smiley, B
AF Croskey, CL
Mitchell, JD
Goldberg, RA
Blix, TA
Rapp, M
Latteck, R
Friedrich, M
Smiley, B
TI Coordinated investigation of plasma and neutral density fluctuations and
particles during the MaCWAVE/MIDAS summer 2002 program
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
AB The MaCWAVE/MIDAS program for investigating high-latitude mesospheric dynamics has produced an extensive set of charged particle, plasma and neutral density measurements. We report on the results from one rocket salvo involving a MaCWAVE and two MIDAS payloads launched within a one-hour period. Each payload carried probes for evaluating the plasma and charged particle environment, and additionally, neutral density measurements were obtained by the CONE instrument on the MIDAS payloads. With the combination of particle and electron/ion density measurements, regions with and without charged particles have been clearly identified, and the plasma measurements outside the particle layers have proven useful to characterize the turbulent activity of the neutral gas.
C1 Penn State Univ, Dept Elect Engn, Commun & Space Sci Lab, University Pk, PA 16802 USA.
NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Norwegian Def Res Estab, N-2007 Kjeller, Norway.
Leibnitz Inst Atmospher Phys, Kuhlungsborn, Germany.
Graz Tech Univ, A-8010 Graz, Austria.
Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA.
RP Croskey, CL (reprint author), Penn State Univ, Dept Elect Engn, Commun & Space Sci Lab, University Pk, PA 16802 USA.
EM ccroskey@psu.edu
RI Goldberg, Richard /E-1881-2012; Rapp, Markus/K-6081-2015;
OI Rapp, Markus/0000-0003-1508-5900; Latteck, Ralph/0000-0002-0001-7473
NR 10
TC 13
Z9 13
U1 0
U2 0
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 1
PY 2004
VL 31
IS 24
AR L24S08
DI 10.1029/2004GL020169
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 861IB
UT WOS:000224408700006
ER
PT J
AU Fritts, DC
Williams, BP
She, CY
Vance, JD
Rap, M
Lubken, FJ
Mullemann, A
Schmidlin, FJ
Goldberg, RA
AF Fritts, DC
Williams, BP
She, CY
Vance, JD
Rap, M
Lubken, FJ
Mullemann, A
Schmidlin, FJ
Goldberg, RA
TI Observations of extreme temperature and wind gradients near the summer
mesopause during the MaCWAVE/MIDAS rocket campaign
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID MIDDLE ATMOSPHERE; THERMAL STRUCTURE
AB We present measurements of extremely large gradients of temperature and zonal wind near the arctic summer mesopause obtained with sodium lidar and falling spheres during the MaCWAVE/MIDAS rocket and ground-based measurement campaign performed at the Andoya Rocket Range (ARR) and the ALOMAR observatory (69.3degreesN, 16.0degreesE) in July 2002. The gradients appear to result from strong gravity wave forcing of the summer mesopause, vertical scale compression and amplitude increases accompanying increasing stratification and decreasing intrinsic phase speeds, and the turbulent transport accompanying wave instability in the lower thermosphere. Zonal wind gradients are found to exceed 100 m s(-1) km(-1), while temperature gradients range from super-adiabatic to similar to40 to 100 K km(-1). We also explore the implications of these large gradients for further instability of the gravity wave and mean fields.
C1 Colorado Res Associates, Boulder, CO 80301 USA.
Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA.
Leibniz Inst Atmospher Phys, D-18225 Kuhlungsborn, Germany.
NASA, Wallops Flight Facil, Wallops Isl, VA 23337 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Fritts, DC (reprint author), Colorado Res Associates, 3380 Mitchell Lane, Boulder, CO 80301 USA.
EM dave@cora.nwra.com
RI Goldberg, Richard /E-1881-2012; Rapp, Markus/K-6081-2015
OI Rapp, Markus/0000-0003-1508-5900
NR 14
TC 34
Z9 34
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 1
PY 2004
VL 31
IS 24
AR L24S06
DI 10.1029/2003GL019389
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 861IB
UT WOS:000224408700002
ER
PT J
AU Goldberg, RA
Fritts, DC
Williams, BP
Lubken, FJ
Rapp, M
Singer, W
Latteck, R
Hoffmann, P
Mullemann, A
Baumgarten, G
Schmidlin, FJ
She, CY
Krueger, DA
AF Goldberg, RA
Fritts, DC
Williams, BP
Lubken, FJ
Rapp, M
Singer, W
Latteck, R
Hoffmann, P
Mullemann, A
Baumgarten, G
Schmidlin, FJ
She, CY
Krueger, DA
TI The MaCWAVE/MIDAS rocket and ground-based measurements of polar summer
dynamics: Overview and mean state structure
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID GRAVITY-WAVES; MESOSCALE VARIABILITY; MESOSPHERE; EXCITATION
AB The MaCWAVE/MIDAS collaborative rocket and ground-based measurement programs were performed at the Andoya Rocket Range and the nearby ALOMAR observatory in northern Norway during July 2002. The summer component of the MaCWAVE ( Mountain and Convective Waves Ascending Vertically) program was focused on gravity wave propagation, instability, and wave-wave and wave-mean flow interaction dynamics contributing to summer mesopause structure and variability. The MIDAS (Middle Atmosphere Dynamics and Structure) program concentrated on small-scale dynamical and microphysical processes near the summer mesopause. Our merged program yielded a comprehensive data set comprising two similar to12-hour rocket salvoes, including 25 MET rockets and 5 sounding rockets, ground-based lidar, radar, and balloon data, and coordinated overpasses of the TIMED satellite. This paper describes the measurement program and rationale, the mean state observed during the rocket salvoes, and evidence that the mean state structure during 2002 differed in important respects from previous years.
C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
NW Res Associates Inc, Colorado Res Associates, Boulder, CO 80301 USA.
Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA.
Inst Atmospher Phys, D-18225 Kuhlungsborn, Germany.
NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA.
RP Goldberg, RA (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
EM richard.a.goldberg@nasa.gov
RI Goldberg, Richard /E-1881-2012; Rapp, Markus/K-6081-2015;
OI Rapp, Markus/0000-0003-1508-5900; Latteck, Ralph/0000-0002-0001-7473;
Baumgarten, Gerd/0000-0002-6727-284X
NR 19
TC 40
Z9 41
U1 0
U2 0
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 1
PY 2004
VL 31
IS 24
AR L24S02
DI 10.1029/2004GL019411
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 861IB
UT WOS:000224408700003
ER
PT J
AU Schoch, A
Baumgarten, G
Fritts, DC
Hoffmann, P
Serafimovich, A
Wang, L
Dalin, P
Mullemann, A
Schmidlin, FJ
AF Schoch, A
Baumgarten, G
Fritts, DC
Hoffmann, P
Serafimovich, A
Wang, L
Dalin, P
Mullemann, A
Schmidlin, FJ
TI Gravity waves in the troposphere and stratosphere during the
MaCWAVE/MIDAS summer rocket program
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID MIDDLE ATMOSPHERE; MST RADAR; PERFORMANCE; PROFILES; DYNAMICS; LIDAR
AB Combining data taken during the MaCWAVE summer rocket campaign at the Andoya Rocket Range (69.3degreesN, 16.0degreesE) with a lidar, radiosondes, falling spheres, and VHF radars at Andoya and at the Esrange, the gravity wave content of the troposphere and stratosphere during the campaign nights was analyzed. The lidar yielded vertical wavelengths and periods of gravity waves in the stratosphere. A Stokes parameter analysis was performed for the radiosonde and falling sphere data to estimate propagation directions of the gravity waves. The wave content in the troposphere was inferred by applying wavelet and cross-spectral methods to the radar data. We found propagation conditions and spectra of the waves to vary with height following the change in the background wind. The waves were excited both at the ground and in the tropopause/lower stratosphere region.
C1 Leibniz Inst Atmospher Phys, D-18225 Kuhlungsborn, Germany.
NW Res Associates Inc, Colorado Res Associates, Boulder, CO 80301 USA.
Swedish Inst Space Phys, SE-98128 Kiruna, Sweden.
NASA, Wallops Flight Facil, Wallops Isl, VA 23337 USA.
RP Schoch, A (reprint author), Leibniz Inst Atmospher Phys, Schlossstr 6, D-18225 Kuhlungsborn, Germany.
EM schoech@iap-kborn.de
RI Rauthe-Schoch, Armin/C-8208-2011;
OI Rauthe-Schoch, Armin/0000-0001-5738-8112; Baumgarten,
Gerd/0000-0002-6727-284X
NR 22
TC 15
Z9 15
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD OCT 1
PY 2004
VL 31
IS 24
AR L24S04
DI 10.1029/2004GL019837
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 861IB
UT WOS:000224408700005
ER
PT J
AU Kempf, S
Srama, R
Altobelli, N
Auer, S
Tschernjawski, V
Bradley, J
Burton, ME
Helfert, S
Johnson, TV
Kruger, H
Moragas-Klostermeyer, G
Grun, E
AF Kempf, S
Srama, R
Altobelli, N
Auer, S
Tschernjawski, V
Bradley, J
Burton, ME
Helfert, S
Johnson, TV
Kruger, H
Moragas-Klostermeyer, G
Grun, E
TI Cassini between Earth and asteroid belt: first in-situ charge
measurements of interplanetary grains
SO ICARUS
LA English
DT Article
DE interplanetary dust; solar wind; celestial mechanics; data reduction
techniques
ID INTERSTELLAR DUST; METEOROID ENVIRONMENT; SOLAR-SYSTEM; ULYSSES; IMPACT;
IONIZATION; DETECTORS; PARTICLES; DYNAMICS; VENUS
AB Dust particles in interplanetary space are expected to charge up to an electrostatic potential of about +5 V mostly by the solar UV (Horanyi, 1996, Annu. Rev. Astrophys. 34, 383). Since the dynamics of charged grains may be quite different from neutral particles, the knowledge of the grain charge Q(d) is highly desirable. In the last two decades, several detectors on spacecraft were flown to measure the dust charge in-situ, but the instrumentation was not capable of determining the dust charge unambiguously. The Cosmic Dust Analyser (CDA) on the Cassini spacecraft includes a charge sensitive entrance grid system (QP detector). While entering the instrument, sufficiently charged particles induce a characteristic charge feature onto the grid system, which allows a reliable determination Of Q(d) as well as of the impact speed upsilon(d). Here we report the first successful in-situ measurement of charged interplanetary dust grains by CDA. Amongst 37 impacts by interplanetary grains registered between November 1999 and January 2000, we identified 6 impacts whose QP signals show a clear feature caused by charged grains, corresponding to Q(d) between 1.3 and 5.4 fC. Knowledge of Q(d) also allows us to estimate the grain mass m(d). Assuming a potential Of phi(d) approximate to +5 V and spheroidal grain morphologies with ratios of the maximum size to the minimum size of less than 2 the masses derived from Q(d) were found to be in excess of 10(-13) kg. The dynamics of such particles are dominated by the Sun's gravity. In the framework of the micro-meteoroid models of the Solar System these grains belong to the core population of interplanetary grains (Divine, 1993, J. Geophys. Res. 98, 17029). Furthermore, a rate of 6 impacts of grains with m(d) greater than or equal to 10(-13) kg during 107 days is in good agreement with the predictions of the interplanetary dust environment model by Staubach et at. (1997, Adv. Space Res. 19, 301). This result demonstrates that charge detectors as the CDA QP system offer a reliable in-situ technique for determining simultaneously both the mass and velocity of big interplanetary grains. The primary CDA subsystem to determine m(d) and upsilon(d), however, is an impact ionisation detector. The majority of the 37 recorded dust impacts produced impact charges are well outside the calibrated range. Moreover, these impacts were usually characterised by impact ionisation signals which differ significantly from signals taken in calibration experiments. In this paper we took advantage of the fact that the measurement of Q(d) is not affected by the subsequent impact of the grain with the detector. By relating m(d) and upsilon(d) derived from Q(d) of the 6 QP impactors to their corresponding ionisation signals we show that in many cases even for energetic impacts outside the calibrated range meaningful values for the dust mass can be obtained. The observed deviations of the ionisation signals from the calibration measurements are likely due to the large amount of plasma generated by such impacts. We discuss the implications of these findings on a meaningful reduction of impact ionisation signals caused by big particle impacts. A new scheme to identify and to evaluate such signals is presented. These finding are of great importance for future Cassini measurements in the saturnian system. (C) 2004 Elsevier Inc. All rights reserved.
C1 Max Planck Inst Kernphys, D-69117 Heidelberg, Germany.
A&M Associates, Basye, VA 22810 USA.
DLR, D-12489 Berlin, Germany.
Jet Prop Lab, Pasadena, CA 91103 USA.
Univ Hawaii, HIGP, Honolulu, HI 96822 USA.
RP Max Planck Inst Kernphys, Saupfercheckweg 1, D-69117 Heidelberg, Germany.
EM sascha.kempf@mpi-hd.mpg.de
OI KEMPF, SASCHA/0000-0001-5236-3004
NR 43
TC 46
Z9 46
U1 2
U2 9
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
EI 1090-2643
J9 ICARUS
JI Icarus
PD OCT
PY 2004
VL 171
IS 2
BP 317
EP 335
DI 10.1016/jcarus.2004.05.017
PG 19
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857ZU
UT WOS:000224160600005
ER
PT J
AU Gustin, J
Feldman, PD
Gerard, JC
Grodent, D
Vidal-Madjar, A
Ben Jaffel, L
Desert, JM
Moos, HW
Sahnow, DJ
Weaver, HA
Wolven, BC
Ajello, JM
Waite, JH
Roueff, E
Abgrall, H
AF Gustin, J
Feldman, PD
Gerard, JC
Grodent, D
Vidal-Madjar, A
Ben Jaffel, L
Desert, JM
Moos, HW
Sahnow, DJ
Weaver, HA
Wolven, BC
Ajello, JM
Waite, JH
Roueff, E
Abgrall, H
TI Jovian auroral spectroscopy with FUSE: analysis of self-absorption and
implications for electron precipitation
SO ICARUS
LA English
DT Article
DE aurora; Jupiter; spectroscopy; ultraviolet observations
ID HOPKINS ULTRAVIOLET TELESCOPE; HUBBLE-SPACE-TELESCOPE;
MOLECULAR-HYDROGEN; JUPITER AURORA; IMPACT EXCITATION; CROSS-SECTIONS;
BAND SYSTEMS; IO FOOTPRINT; H-2; EMISSION
AB High-resolution (similar to 0.22 Angstrom) spectra of the north jovian aurora were obtained in the 905-1180 Angstrom window with the Far Ultraviolet Spectroscopic Explorer (FUSE) on October 28, 2000. The FUSE instrument resolves the rotational structure of the H-2 spectra and the spectral range allows the study of self-absorption. Below 1100 Angstrom, transitions connecting to the upsilon" less than or equal to 2 levels of the H-2 ground state are partially or totally absorbed by the overlying H2 molecules. The FUSE spectra provide information on the overlying H2 column and on the vibrational distribution of H-2. Transitions from high-energy H-2 Rydberg states and treatment of self-absorption are considered in our synthetic spectral generator. We show comparisons between synthetic and observed spectra in the 920-970, 1030-1080, and 1090-1180 Angstrom spectral windows. In a first approach (single-layer model), the synthetic spectra are venerated in a thin emitting layer and the emerging photons are absorbed by a layer located above the source. It is found that the parameters of the single-layer model best fitting the three spectral windows are 850, 800, and 800 K respectively for the H-2 gas temperature and 1.3 x 10(18), 1.5 x 10(20), and 1.3 x 10(20) cm(-2) for the H-2 self-absorbing vertical column respectively. Comparison between the H-2 column and a 1-D atmospheric model indicates that the short-wavelength FUV auroral emission originates from just above the homopause. This is confirmed by the high H-2 rovibrational temperatures, close to those deduced from spectral analyses of H-3(+) auroral emission. In a second approach, the synthetic spectral generator is coupled with a vertically distributed 3 energy degradation model, where the only input is the energy distribution of incoming electrons (multi-layer model). The model that best fits globally the three FUSE spectra is a sum of Maxwellian functions, with characteristic energies ranging from 1 to 100 keV, giving rise to an emission peak located at 5 mubar, that is similar to 100 km below the methane homopause. This multi-layer model is also applied to a re-analysis of the Hopkins Ultraviolet Telescope (HUT) auroral spectrum and accounts for the H2 self-absorption as well as the methane absorption. It is found that no additional discrete soft electron precipitation is necessary to fit either the FUSE or the HUT observations. (C) 2004 Elsevier Inc. All rights reserved.
C1 Lab Phys Atmospher & Planetaire, B-4000 Liege, Belgium.
Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA.
Inst Astrophys, F-75014 Paris, France.
Johns Hopkins Univ, Appl Phys Lab, Dept Space, Laurel, MD 20723 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Michigan, Ann Arbor, MI 48109 USA.
Observ Paris, Sect Meudon, DAEC, F-92195 Meudon, France.
CNRS, UMR 8631, F-92195 Meudon, France.
RP Lab Phys Atmospher & Planetaire, Allee 6 Aout 17, B-4000 Liege, Belgium.
EM gustin@astro.ulg.ac.be
RI Weaver, Harold/D-9188-2016;
OI Wolven, Brian/0000-0003-2858-2332; GERARD,
Jean-Claude/0000-0002-8565-8746
NR 34
TC 28
Z9 28
U1 0
U2 0
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
EI 1090-2643
J9 ICARUS
JI Icarus
PD OCT
PY 2004
VL 171
IS 2
BP 336
EP 355
DI 10.1016/j.icarus.2004.06.005
PG 20
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857ZU
UT WOS:000224160600006
ER
PT J
AU Showalter, MR
AF Showalter, MR
TI Disentangling Saturn's F ring. I. Clump orbits and lifetimes
SO ICARUS
LA English
DT Article
DE planetary rings; Saturn; planetary dynamics
ID PLANE CROSSINGS; STELLAR OCCULTATION; RADIO OCCULTATION; NOVEMBER 1995;
SATELLITES; PROMETHEUS; AUGUST; COLLISIONS; VOYAGER-2; PANDORA
AB A comprehensive analysis of the Voyager images reveals the kinematics and lifetimes of clumps in the F Ring. At any given time, the ring has 2-3 major clumps, each several times brighter than the typical ring, plus numerous smaller features. A total of 34 individual clumps have been tracked over periods of 1-7 weeks. The clumps orbited at measurably different rates, implying a 100-km range of semimajor axes centered on 140,220 km. Most are centered around the nominal mean motion of the ring's core, but a few outliers may be associated with a different strand, or with no strand at all. Most clumps change very little over the similar to 30 days that they can be detected; however, no clump persisted for the nine-month interval between the two Voyager encounters. The brightest Voyager 2 clump is unusual in that it travels at a rapid mean motion and seems to be associated with the formation of several other clumps. (C) 2004 Elsevier Inc. All rights reserved.
C1 Stanford Univ, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Showalter, MR (reprint author), Stanford Univ, NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA.
EM mshowalter@mail.arc.nasa.gov
NR 42
TC 24
Z9 24
U1 0
U2 1
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD OCT
PY 2004
VL 171
IS 2
BP 356
EP 371
DI 10.1016/j.icarus.2004.05.006
PG 16
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857ZU
UT WOS:000224160600007
ER
PT J
AU Spilker, LJ
Pilorz, S
Lane, AL
Nelson, RM
Pollard, B
Russell, CT
AF Spilker, LJ
Pilorz, S
Lane, AL
Nelson, RM
Pollard, B
Russell, CT
TI Saturn A ring surface mass densities from spiral density wave dispersion
behavior
SO ICARUS
LA English
DT Article
DE planetary rings; Saturn; resonances; data reduction techniques
ID VOYAGER-1 RADIO OCCULTATION; PLANETARY RINGS; RESONANCE STRUCTURES;
SATELLITES; WAVELENGTHS; FEATURES
AB We have undertaken an analysis of the Voyager photopolarimeter (PPS) stellar occultation data of Saturn's A ring. The Voyager PPS observed the bright star delta Scorpii as it was occulted by Saturn's main rings during the spacecraft flyby of the Saturn system in 1981. The occultation measurement produced a ring profile with radial resolution of approximately 100 m, and radial structure is evident in the profile down to the resolution limit. We have applied an autoregressive technique to the data for estimating the power spectrum as a function of radius, which has allowed us to identify 40 spiral density waves in Saturn's A ring, associated with the strongest torques due to forcing from the moons. The majority of the detected waves are observed to disperse linearly in regions beginning a few kilometers from the resonance location. We have used the dispersion behavior for those waves to calculate local surface mass densities in the vicinity of each wave. We find that the inner three-quarters of the A ring (up to the beginning of the Encke gap) has an average surface mass density of 43.8 +/- 7.9 g cm(-2), while the outer region has an average surface mass density of 28.3 +/- 10.8 g cm(-2). The two regions have different mean surface mass densities with a significance of approximately 0.999993, as estimated with a T-statistic, which corresponds to about 4.5sigma. While the mean optical depth of the A ring increases slightly with increasing distance from Saturn, we find that it is not significantly correlated with the surface mass density; the two quantities having a linear Pearson's correlation coefficient of r(corr) approximate to -0.03. The variation of mass density, independent of PPS optical depth, is consistent with previous conjectures that the particle size distribution and composition are not constant across the entire A ring, particularly in the very outer portion. We estimate the mass of Saturn's A ring from our Surface mass density estimates as 4.9 x 10(21) gm, or 8.61 x 10(-9) of the mass of Saturn, roughly equivalent to the mass of a 110-km diameter icy satellite. This mass is almost 25% smaller than estimates from previous studies, but is well within the expected errors of the derived mass densities. We also identified three previously unstudied features which exhibit linear dispersion. The strongest of these features is tentatively identified as the Janus 13:11 density wave. The other two features do not fall near any known satellite resonances and may represent density waves created by previously undetected satellites. (C) 2004 Elsevier Inc. All rights reserved.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Idaho, Coll Engn, Idaho Space Grant Consortium, Moscow, ID 83844 USA.
Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA.
RP Spilker, LJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 230-205, Pasadena, CA 91109 USA.
EM linda.j.spilker@jpl.nasa.gov
OI Russell, Christopher/0000-0003-1639-8298
NR 40
TC 18
Z9 18
U1 0
U2 0
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD OCT
PY 2004
VL 171
IS 2
BP 372
EP 390
DI 10.1016/j.icarus.2004.05.016
PG 19
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857ZU
UT WOS:000224160600008
ER
PT J
AU Moore, JM
Schenk, PM
Bruesch, LS
Asphaug, E
McKinnon, WB
AF Moore, JM
Schenk, PM
Bruesch, LS
Asphaug, E
McKinnon, WB
TI Large impact features on middle-sized icy satellites
SO ICARUS
LA English
DT Article
DE satellites of Saturn; satellites of Uranus; impact processes; surfaces;
satellite
ID PARTICLE HYDRODYNAMICS; INTERNAL STRUCTURE; SATURN SYSTEM; GANYMEDE;
SIMULATIONS; CALLISTO; HISTORY; EUROPA; EJECTA; PHOTOMETRY
AB All of the large impact features of the middle-sized icy satellites of Saturn and Uranus that were clearly observed by the Voyager spacecraft are described. New image mosaics and stereo-and-photoclinometrically-derived digital elevation models are presented. Landforms related to large impact features, such as secondary craters and possible antipodal effects are examined and evaluated. Of the large impacts, Odysseus on Tethys appears to have had the most profound effect on its "target" satellite of any of the impact features we examined. Our modeling suggests that the Odysseus impact may have caused the prompt formation of Ithaca Chasma, a belt of tectonic troughs that roughly follow a great circle normal to the center of Odysseus, although other hypotheses remain viable. We identify probable secondary cratering from Tirawa on Rhea. We attribute a number of converging coalescing crater chains on Rhea to a putative, possibly relatively fresh, similar to 350 km-diameter impact feature. We examine the antipodes of Odysseus, the putative similar to 350 km-diameter Rhean impact feature, and Tirawa, and conclude that evidence from Voyager data for damage from seismic focusing is equivocal, although our modeling results indicate that such damage may have occurred. We propose a number of observations and tests for Cassini that offer the opportunity to differentiate among the various explanations and speculations reviewed and evaluated in this study. Published by Elsevier Inc.
C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA.
Lunar & Planetary Inst, Houston, TX 77058 USA.
Univ Calif Santa Cruz, Dept Earth Sci, Santa Cruz, CA 95064 USA.
Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA.
Washington Univ, McDonnell Ctr Space Sci, St Louis, MO 63130 USA.
RP NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA.
EM jeff.moore@nasa.gov
NR 73
TC 34
Z9 34
U1 0
U2 7
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
EI 1090-2643
J9 ICARUS
JI Icarus
PD OCT
PY 2004
VL 171
IS 2
BP 421
EP 443
DI 10.1016/j.icarus.2004.05.009
PG 23
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857ZU
UT WOS:000224160600011
ER
PT J
AU Lisse, CM
Fernandez, YR
A'Hearn, MF
Grun, E
Kaufl, HU
Osip, DJ
Lien, DJ
Kostiuk, T
Peschke, SB
Walker, RG
AF Lisse, CM
Fernandez, YR
A'Hearn, MF
Grun, E
Kaufl, HU
Osip, DJ
Lien, DJ
Kostiuk, T
Peschke, SB
Walker, RG
TI A tale of two very different comets: ISO and MSX measurements of dust
emission from 126P/IRAS (1996) and 2P/Encke (1997)
SO ICARUS
LA English
DT Article
DE comets; infrared observations; photometry; dust
ID MIDCOURSE-SPACE-EXPERIMENT; INFRARED PHOTOMETRY; OPTICAL-PROPERTIES;
ZODIACAL CLOUD; SOLAR-SYSTEM; HALE-BOPP; PARTICLES; NUCLEUS; GRAINS;
HALLEY
AB We present the characteristics of the dust comae of two comets, 126P/IRAS, a member of the Halley family (a near-isotropic comet), and 2P/Encke, an ecliptic comet. We have primarily used mid- and far-infrared data obtained by the ISOPHOT instrument aboard the Infrared Space Observatory (ISO) in 1996 and 1997, and mid-infrared data obtained by the SPIRIT III instrument aboard the Midcourse Space Experiment (MSX) in 1996. We find that the dust grains emitted by the two comets have markedly different thermal and physical properties. P/IRAS's dust grain size distribution appears to be similar to that of fellow family member 1P/Halley, with grains smaller than 5 microns dominating by surface area, whereas P/Encke emits a much higher fraction of big (20 mum and higher) grains, with the grain mass distribution being similar to that which is inferred for the interplanetary dust population. P/Encke's dearth of micron-scale grains accounts for its visible-wavelength classification as a "gassy" comet. These conclusions are based on analyses of both imaging and spectrophotometry of the two comets; this combination provides a powerful way to constrain cometary dust properties. Specifically, P/IRAS was observed preperihelion while 1.71 AU from the Sun, and seen to have a 15-arcmin long mid-infrared dust tail pointing in the antisolar direction. No sunward spike was seen despite the vantage point being nearly in the comet's orbital plane. The tail's total mass at the time was about 8 x 109 kg. The spectral energy distribution (SED) is best fit by a modified greybody with temperature T = 265 +/- 15 K and emissivity epsilon proportional to a steep power law in wavelength lambda : epsilon alpha lambda(-alpha), where alpha = 0.50 +/- 0.20 (2sigma). This temperature is elevated with respect to the expected equilibrium temperature for this heliocentric distance. The dust mass loss rate was between 150-600 kg/s (95% confidence), the dust-to-gas mass loss ratio was about 3.3, and the albedo of the dust was 0.15 +/- 0.03. Carbonaceous material is depleted in the comet's dust by a factor of 2-3, paralleling the C-2 depletion in P/IRAS's gas coma. P/Encke, on the other hand, observed while 1.17 AU from the Sun, had an SED that is best fit by a Planck function with T = 270 +/- 15 K and no emissivity falloff. The dust mass loss rate was 70-280 kg/s (95% confidence), the dust-to-gas mass loss ratio was about 2.3, and the albedo of the dust was about 0.06 +/- 0.02. These conclusions are consistent with the strongly curved dust tail and bright dust trail seen by Reach et al. (2000; Icarus 148, 80) in their ISO 12-mun imaging of P/Encke. The observed differences in the P/IRAS and P/Encke dust are most likely due to the less evolved and insolated state of the P/IRAS nuclear surface. If the dust emission behavior of P/Encke is typical of other ecliptic comets, then comets are the major supplier of the interplanetary dust cloud. (C) 2004 Elsevier Inc. All rights reserved.
C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
Max Planck Inst Kernphys, D-69117 Heidelberg, Germany.
Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA.
Las Campanas Observ, Carnegie Observ, La Serena, Chile.
Oklahoma State Univ, Dept Phys, Stillwater, OK 74078 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
ISO Data Ctr, ESA, Satellite Tracking Stn, E-28080 Madrid, Spain.
Monterey Inst Res Astron, Marina Del Rey, CA 93933 USA.
RP Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
EM lisse@astro.umd.edu
RI Kostiuk, Theodor/A-3077-2014; Lisse, Carey/B-7772-2016;
OI Lisse, Carey/0000-0002-9548-1526; Fernandez, Yanga/0000-0003-1156-9721
NR 71
TC 30
Z9 30
U1 0
U2 1
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
EI 1090-2643
J9 ICARUS
JI Icarus
PD OCT
PY 2004
VL 171
IS 2
BP 444
EP 462
DI 10.1016/j.icarus.2004.05.015
PG 19
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857ZU
UT WOS:000224160600012
ER
PT J
AU Hodyss, R
McDonald, G
Sarker, N
Smith, MA
Beauchamp, PA
Beauchamp, JL
AF Hodyss, R
McDonald, G
Sarker, N
Smith, MA
Beauchamp, PA
Beauchamp, JL
TI Fluorescence spectra of Titan tholins: in-situ detection of
astrobiologically interesting areas on Titan's surface
SO ICARUS
LA English
DT Article
DE Titan; organic chemistry; prebiotic chemistry; prebiotic environments
ID ATMOSPHERE; SIMULATION; AEROSOLS; ANALOGS; HAZE
AB We report the three-dimensional fluorescence spectra of Titan tholins in water and acetonitrile, and separate some of the fluorescent components of tholins using two-dimensional thin layer chromatography. In acetonitrile, tholins exhibit a broad fluorescence with a maximum at 471 nm, and an excitation maximum at 410 nm. The fluorescence spectrum of a water extraction displays a more complicated spectrum with multiple peaks. TLC results indicate the presence of at least three distinct fluorescent species. In addition, we obtained the two-dimensional fluorescence spectrum of tholins in water ice at 77 K, close to the surface temperature of Titan. The fluorescence of tholins in a 77 K ice matrix is red-shifted in comparison to a water solution, and undergoes a further red-shift when the water solution is heated prior to freezing. These results suggest that a simple fluorescence probe could be used on the surface of Titan to identify sites where tholins have been mixed with water, and possibly reveal information about the extent of heating the tholin-water mixture has undergone. This would be useful for a future mission with the goal of examining the organic chemistry of Titan. (C) 2004 Elsevier Inc. All rights reserved.
C1 CALTECH, Arthur Amos Noyes Lab Chem Phys, Pasadena, CA 91125 USA.
Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Arizona, Dept Chem, Tucson, AZ 85721 USA.
RP Hodyss, R (reprint author), CALTECH, Arthur Amos Noyes Lab Chem Phys, Pasadena, CA 91125 USA.
EM hodyss@caltech.edu
NR 15
TC 16
Z9 16
U1 0
U2 8
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD OCT
PY 2004
VL 171
IS 2
BP 525
EP 530
DI 10.1016/j.icarus.2004.05.011
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857ZU
UT WOS:000224160600017
ER
PT J
AU Piatek, JL
Hapke, BW
Nelson, RM
Smythe, WD
Hale, AS
AF Piatek, JL
Hapke, BW
Nelson, RM
Smythe, WD
Hale, AS
TI Scattering properties of planetary regolith analogs
SO ICARUS
LA English
DT Article
DE photometry; regoliths; radiative transfer; polarimetry
ID BIDIRECTIONAL REFLECTANCE SPECTROSCOPY; COHERENT-BACKSCATTER;
WEAK-LOCALIZATION; SPHERICAL-PARTICLES; DENSE DISTRIBUTION;
LIGHT-SCATTERING; PHASE FUNCTION; ASYMMETRY PARAMETERS;
RADIATIVE-TRANSFER; DISORDERED MEDIA
AB The physics of scattering of electromagnetic waves by media in which the particles are in contact, such as planetary regoliths, has been thought to be relatively well understood when the particles are larger than the wavelength. However, this is not true when the particles are comparable with or smaller than the wavelength. We have measured the scattering parameters of planetary regolith analogs consisting of suites of well-sorted abrasives whose particles ranged from larger to smaller than the wavelength. We measured the variation of reflectance as the phase angle varied from 0.05degrees to 140degrees. The following parameters of the media were then deduced: the single scattering albedo, single scattering phase function, transport mean free path, and scattering, absorption, and extinction coefficients. A scattering model based on the equation of radiative transfer was empirically able to describe quantitatively the variation of intensity with angle for each sample. Thus, such models can be used to characterize scattering from regoliths even when the particles are smaller than the wavelength. The scattering parameters were remarkably insensitive to particle size. These results are contrary to theoretical predictions, but are consistent with earlier measurements of alumina abrasives that were restricted to small phase angles. They imply that a basic assumption made by virtually all regolith scattering models, that the regolith particles are the fundamental scattering units of the medium, is incorrect. Our understanding of scattering by regoliths appears to be incomplete, even when the particles are larger than the wavelength. (C) 2004 Elsevier Inc. All rights reserved.
C1 Univ Pittsburgh, Space Res Coordinat Ctr 200, Dept Geol & Planetary Sci, Pittsburgh, PA 15260 USA.
Jet Prop Lab, Pasadena, CA 91109 USA.
RP Piatek, JL (reprint author), Univ Tennessee, Dept Earth & Planetary Sci, 306 Geol Sci Bldg, Knoxville, TN 37996 USA.
EM jpiatek@utk.edu
NR 56
TC 40
Z9 42
U1 0
U2 2
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD OCT
PY 2004
VL 171
IS 2
BP 531
EP 545
DI 10.1016/j.icarus.2004.05.019
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857ZU
UT WOS:000224160600018
ER
PT J
AU Ryer, CH
AF Ryer, CH
TI Laboratory evidence for behavioural impairment of fish escaping trawls:
a review
SO ICES JOURNAL OF MARINE SCIENCE
LA English
DT Article; Proceedings Paper
CT 2nd International Symposium on Fish Behaviour in Exploited Ecosystems
CY JUN 23-26, 2003
CL Bergen, NORWAY
SP Int Council Explorat Sea
DE by-catch; predation; stress; trawl
ID POLLOCK THERAGRA-CHALCOGRAMMA; JUVENILE WALLEYE POLLOCK;
PREDATOR-AVOIDANCE; RAINBOW-TROUT; HABITAT STRUCTURE; LIGHT-INTENSITY;
COHO SALMON; COD-END; CODENDS; VULNERABILITY
AB It is now widely accepted that for some species a proportion of the undersized fish escaping trawl codends die as a direct result of stress, with 10% to 30% mortality commonly cited. It has also been suggested that there may be indirect or behaviourally mediated mortality; fish that encounter and escape the trawl, only to experience stress-induced behavioural deficits and succumb to predators in the hours or days afterwards. The goal of this review was to evaluate the plausibility of this behaviourally mediated, yet unobserved mortality. Three laboratory studies utilizing cod (Gadus morhua), walleye pollock (Theragra chalcogramma), and sablefish (Anoplopoma fimbria) have assayed for behavioural impairment in fish following application of stressors designed to simulate entrainment and escape from trawls. Where impairments in anti-predator capabilities occurred, it was determined that trawl-stressed fish exhibited reduced swimming speed, reduced shoal cohesion, and reduced predator vigilance compared to control fish. Although stressed fish appeared to rapidly recover their ability to avoid being eaten by predators, measurements of more subtle aspects of escapee behaviour suggest that impairments may persist for days after stressor application. Although these studies demonstrate that more investigation is required, when combined with a more extensive literature demonstrating that a variety of stressors can impair fish anti-predator behaviour, it is reasonable to conclude that many fish species escaping trawl codends will likely suffer behavioural deficits that subject them to elevated predation risk. As such, there is probably mortality associated with trawl fisheries that is generally unrecognized, unmeasured, and unaccounted for in current stock assessment models. Further, these studies demonstrate that behavioural competency needs to be considered in the design and implementation of by-catch reduction devises and strategies. Published by Elsevier Ltd on behalf of International Council for the Exploration of the Sea.
C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Fisheries Behav Ecol Program, Hatfield Marine Sci Ctr, Newport, OR 97365 USA.
RP Ryer, CH (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Fisheries Behav Ecol Program, Hatfield Marine Sci Ctr, 2030 Marine Sci Dr, Newport, OR 97365 USA.
EM cliff.ryer@noaa.gov
NR 50
TC 23
Z9 23
U1 0
U2 6
PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD
PI LONDON
PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND
SN 1054-3139
J9 ICES J MAR SCI
JI ICES J. Mar. Sci.
PD OCT
PY 2004
VL 61
IS 7
BP 1157
EP 1164
DI 10.1016/j.icesjms.2004.06.004
PG 8
WC Fisheries; Marine & Freshwater Biology; Oceanography
SC Fisheries; Marine & Freshwater Biology; Oceanography
GA 869QH
UT WOS:000224998600020
ER
PT J
AU Scoglio, C
Anjali, T
de Oliveira, JC
Akyildiz, IF
Uhl, G
AF Scoglio, C
Anjali, T
de Oliveira, JC
Akyildiz, IF
Uhl, G
TI TEAM: A traffic engineering automated manager for DiffServ-based MPLS
networks
SO IEEE COMMUNICATIONS MAGAZINE
LA English
DT Article
ID PROVIDING QOS; ARCHITECTURE; POLICY
AB In this article an automated manager called Traffic Engineering Automated Manager (TEAM) for DiffServ/MPLS networks is introduced, and its design and implementation details are discussed. TEAM is designed for complete automated management of an Internet domain. TEAM is an adaptive manager that provides the required quality of service to the users and reduces the congestion in the network. The former is achieved by reserving bandwidth resources for the requests and the latter by distributing the load efficiently. These goals are achieved by online measurements of the network state. TEAM is composed of a Traffic Engineering Tool (TET), which adaptively manages the bandwidth and routes in the network, a Measurement and Performance Evaluation Tool (MPET), which measures important parameters in the network and inputs them to the TET, and a Simulation Tool (ST), which may be used by TET to consolidate its decisions. These three tools work in synergy to achieve the desired network operation objectives. The experimental results demonstrate the efficiency of TEAM as a network manager in different and unpredictable traffic conditions at the expense of a limited increase in the computational complexity and costs.
C1 Georgia Inst Technol, Atlanta, GA 30332 USA.
IIT, Chicago, IL 60616 USA.
Drexel Univ, Philadelphia, PA 19104 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Scoglio, C (reprint author), Georgia Inst Technol, Atlanta, GA 30332 USA.
EM caterina@ece.gatech.edu; tricha@ece.iit.edu; jau@ece.drexel.edu;
ian@ece.gatech.edu; uhl@gsfc.nasa.gov
RI Akyildiz, Ian/G-7136-2011
OI Akyildiz, Ian/0000-0002-8099-3529
NR 15
TC 13
Z9 13
U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0163-6804
J9 IEEE COMMUN MAG
JI IEEE Commun. Mag.
PD OCT
PY 2004
VL 42
IS 10
BP 134
EP 145
DI 10.1109/MCOM.2004.1341272
PG 12
WC Engineering, Electrical & Electronic; Telecommunications
SC Engineering; Telecommunications
GA 860GR
UT WOS:000224331000018
ER
PT J
AU Piepmeier, JR
Simon, NK
AF Piepmeier, J. R.
Simon, N. K.
TI A Polarimetric Extension of the van Cittert-Zernike Theorem for Use With
Microwave Interferometers
SO IEEE GEOSCIENCE AND REMOTE SENSING LETTERS
LA English
DT Article
DE Interferometer; polarization; polarimetric; radiometer
AB The van Cittert-Zernike theorem describes the Fourier transform relationship between an extended source and its visibility function. Developments in classical optics texts use scalar field formulations for the theorem. Here, we develop a polarimetric extension to the van Cittert-Zernike theorem with applications to passive microwave earth remote sensing. The development provides insight into the mechanics of two-dimensional inteferometric imaging, particularly the effects of polarization basis differences between the scene and the observer.
C1 [Piepmeier, J. R.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
[Simon, N. K.] QSS Grp Inc, Lanham, MD 20706 USA.
[Simon, N. K.] Int Spy Museum, Washington, DC 20004 USA.
RP Piepmeier, JR (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
EM jeff.piep-meier@nasa.gov
FU National Aeronautic and Space Administration
FX Manuscript received February 2, 2004; revised June 23, 2004. This work
was supported by the National Aeronautic and Space Administration Earth
Science New Investigator Program.
NR 12
TC 3
Z9 3
U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 1545-598X
J9 IEEE GEOSCI REMOTE S
JI IEEE Geosci. Remote Sens. Lett.
PD OCT
PY 2004
VL 1
IS 4
BP 300
EP 303
DI 10.1109/LGRS.2004.835220
PG 4
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA V23EF
UT WOS:000208325400015
ER
PT J
AU Liu, AK
Ramp, SR
Zhao, YH
Tang, TY
AF Liu, AK
Ramp, SR
Zhao, YH
Tang, TY
TI A case study of internal solitary wave propagation during ASIAEX 2001
SO IEEE JOURNAL OF OCEANIC ENGINEERING
LA English
DT Article
DE internal waves; remote sensing; shallow water
ID CHINA SEAS; SULU SEA; EVOLUTION
AB During the recent Asian Seas International Acoustics Experiment (ASIAEX), extensive current meter moorings were deployed around the continental shelf-break area in the northeastern South China Sea. Thirteen RADARSAT SAR images were collected during the field test to integrate with thee in situ measurements from the moorings, ship-board sensors, and conductivity/temperature/depth (CTD) casts. Besides providing a synoptic view of the entire region, satellite imagery is very useful for tracking the internal waves, locating surface fronts, and identifying mesoscale features. During ASIAEX in May 2001, many large internal waves were observed at the test area and were the major oceanic features studied for acoustic volume interaction. Based on the internal wave distribution maps compiled from satellite data, the wave crests can be as long as 200 km with an amplitude of 100 m. Environmental parameters have been calculated based on extensive CTD casts data near the ASIAEX area. Nonlinear internal wave models have been applied to integrate and assimilate both synthetic aperture radar (SAR) and mooring data. Using SAR data in deep water as an initial condition, numerical simulations produced the wave evolution on the continental shelf and compared reasonably well with the mooring measurements at the downstream station. The shoaling, turning, and dissipation of large internal waves at the shelf break have been studied and are very important issues for acoustic propagation.
C1 NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA.
USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA.
Caelum Res Corp, Rockville, MD 20805 USA.
Natl Taiwan Univ, Inst Oceanog, Taipei 106, Taiwan.
RP Liu, AK (reprint author), NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA.
EM Antony.A.Liu@nasa.gov
NR 20
TC 60
Z9 69
U1 2
U2 4
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0364-9059
J9 IEEE J OCEANIC ENG
JI IEEE J. Ocean. Eng.
PD OCT
PY 2004
VL 29
IS 4
BP 1144
EP 1156
DI 10.1109/JOE.2004.841392
PG 13
WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical &
Electronic; Oceanography
SC Engineering; Oceanography
GA 893PW
UT WOS:000226732700023
ER
PT J
AU Ramp, SR
Tang, TY
Duda, TF
Lynch, JF
Liu, AK
Chiu, CS
Bahr, FL
Kim, HR
Yang, YJ
AF Ramp, SR
Tang, TY
Duda, TF
Lynch, JF
Liu, AK
Chiu, CS
Bahr, FL
Kim, HR
Yang, YJ
TI Internal solitons in the northeastern South China Sea - Part I: Sources
and deep water propagation
SO IEEE JOURNAL OF OCEANIC ENGINEERING
LA English
DT Article
DE baroclinic tides; nonlinear internal waves; ocean currents
ID INTERFACIAL SOLITARY WAVES; SULU SEA; STRATIFIED FLUIDS; NONLINEAR
MODEL; FINITE DEPTH; OCEAN; SLOPE; SHELF; FLOW; TOPEX/POSEIDON
AB A moored array of current, temperature, conductivity, and pressure sensors was deployed across the Chinese continental shelf and slope in support of the Asian Seas International Acoustics Experiment. The goal of the observations was to quantify the water column variability in order to understand the along- and across-shore low-frequency acoustic propagation in shallow water. The moorings were deployed from April 21-May 19,2001 and sampled at 1-5 min intervals to capture the full range of temporal variability without aliasing the internal wave field. The dominant oceanographic signal by far was in fact the highly nonlinear internal waves (or solitons) which were generated near the Batan Islands in the Luzon Strait and propagated 485 km across deep water to the observation region. Dubbed trans-basin waves, to distinguish them from other, smaller nonlinear waves generated locally near the shelf break, these waves had amplitudes ranging from 24 to greater than 140 m and were among the largest such waves ever observed in the world's oceans. The waves arrived at the most offshore mooring in two clusters lasting 7-8 days each separated by five days when no waves were observed. Within each cluster, two types of waves arrived which have been named type-a and type-b. The type-a waves had greater amplitude than the type-b waves and arrived with remarkable regularity at the same time each day, 24 h apart. The type-b waves were weaker than the type-a waves, arrived an hour later each day, and generally consisted of a single soliton growing out of the center of the wave packet. Comparison with modeled barotropic tides from the generation region revealed that: 1) The two clusters were generated around the time of the spring tides in the Luzon strait; and 2) The type-a waves were generated on the strong side of the diurnal inequality while the type-b waves were generated on the weaker beat. The position of the Kuroshio intrusion into the Luzon Strait may modulate the strength of the waves being produced. As the waves shoaled, the huge lead solitons first split into two solitons then merged together into a broad region of thermocline depression at depths less than 120 m. Elevation waves sprang up behind them as they continued to propagate onshore. The elevation waves also grew out of regions where the locally-generated internal tide forced the main thermocline down near the bottom. The "critical point" alpha where the upper and lower layers were equal was a good indicator of when the depression or elevation waves would form. however this was not a static point. but rather varied in both space and time according to the presence or absence of the internal tides and the incoming trans-basin waves themselves.
C1 USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA.
Natl Taiwan Univ, Inst Oceanog, Taipei 10764, Taiwan.
USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA.
Seoul Natl Univ, Seoul, South Korea.
Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Ramp, SR (reprint author), USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA.
RI Duda, Timothy/A-7282-2010;
OI Duda, Timothy/0000-0002-5797-5955; Yang, Yiing-Jang/0000-0002-6637-9311
NR 52
TC 197
Z9 219
U1 6
U2 33
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0364-9059
J9 IEEE J OCEANIC ENG
JI IEEE J. Ocean. Eng.
PD OCT
PY 2004
VL 29
IS 4
BP 1157
EP 1181
DI 10.1109/JOE.840839
PG 25
WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical &
Electronic; Oceanography
SC Engineering; Oceanography
GA 893PW
UT WOS:000226732700024
ER
PT J
AU Yang, YJ
Tang, TY
Chang, MH
Liu, AK
Hsu, MK
Ramp, SR
AF Yang, YJ
Tang, TY
Chang, MH
Liu, AK
Hsu, MK
Ramp, SR
TI Solitons northeast of Tung-Sha Island during the ASIAEX pilot studies
SO IEEE JOURNAL OF OCEANIC ENGINEERING
LA English
DT Article
DE internal wave; nonlinear wave; soliton; South China Sea (SCS)
ID INTERNAL SOLITARY WAVES; SLOPE-SHELF TOPOGRAPHY; SHALLOW-WATER; CHINA
SEAS; BREAKING; PROPAGATION; TRANSFORMATION; GENERATION; REFRACTION;
EVOLUTION
AB In a recent study, satellite images have shown that internal solitons are active in the northern South China Sea (SCS). During the Asian Seas International Acoustic Experiment (ASIAEX) pilot studies, current profiler and thermistor chain moorings were deployed in the spring of 1999 and 2000 to investigate internal solitons northeast of Tbng-Sha Island on the continental slope of the northern SCS. Most of the observed internal solitons were first baroclinic mode depression waves. The largest horizontal current velocity, vertical displacement, and temperature variation induced by the internal solitons were around 240 cm/s, 106 m, and 11 degreesC, respectively, while the estimated nonlinear phase speed was primarily westward at 152 4 cm/s. The observed internal solitons could be categorized as four types. The first type is the incoming wave from deep water and can be described reasonably well with the KdV equation. The second and third types are in the transition zone before and close to the turning point (where the upper and lower layer depths are equal), respectively. These two types of solitons were generally near the wave-breaking stage. The fourth type of soliton is a second baroclinic mode and probably was locally generated. The time evolutions are asymmetric, especially at the middle depths. A temperature kink following the main pulse of the soliton is often seen. Higher order nonlinear and shallow topographic effects could be the primary cause for these features. The appearance/disappearance of internal solitons coincides mostly with spring/neap tide. The internal soliton is irregularly seen during the neap tide period and its amplitude is generally small. The time interval between two leading solitons is generally around 12 h. The first baroclinic mode of the semidiurnal tide has a larger amplitude than the diurnal tide and could redistribute its energy into the soliton.
C1 Chinese Naval Acad, Dept Marine Sci, Kaohsiung 813, Taiwan.
Natl Taiwan Univ, Inst Oceanog, Taipei 106, Taiwan.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Wu Inst Technol, Taipei 112, Taiwan.
USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA.
RP Yang, YJ (reprint author), Chinese Naval Acad, Dept Marine Sci, Kaohsiung 813, Taiwan.
OI Yang, Yiing-Jang/0000-0002-6637-9311; CHANG,
MING-HUEI/0000-0002-6409-7652
NR 41
TC 95
Z9 104
U1 1
U2 9
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0364-9059
J9 IEEE J OCEANIC ENG
JI IEEE J. Ocean. Eng.
PD OCT
PY 2004
VL 29
IS 4
BP 1182
EP 1199
DI 10.1109/JOE.2004.841424
PG 18
WC Engineering, Civil; Engineering, Ocean; Engineering, Electrical &
Electronic; Oceanography
SC Engineering; Oceanography
GA 893PW
UT WOS:000226732700025
ER
PT J
AU Maslov, AV
Ning, CZ
AF Maslov, AV
Ning, CZ
TI Modal gain in a semiconductor nanowire laser with anisotropic
bandstructure
SO IEEE JOURNAL OF QUANTUM ELECTRONICS
LA English
DT Article
DE nanotechnology; semiconductor device modeling; semiconductor lasers
ID PARAMETERS; EMISSION; GAN
AB We investigate optical gain for the modes guided by semiconductor nanowires. We focus on optically anisotropic wurtzite-type semiconductors (such as GaN) and the situation when the optical axis of the crystal coincides with the geometrical axis of the nanowire. For GaN nanowire lasers, the calculation of the modal gain requires the knowledge of two confinement factors for a given mode and two gain coefficients for the bulk crystal. We show that the confinement factors for nanowire lasers are very large in comparison to those for heterostructure lasers, and can even exceed unity. To estimate the bulk gain in GaN we use the free-carrier model and emphasize the importance of accounting for anisotropy of gain. Using the calculated confinement factors and bulk gain, we predict that free-standing nanowires with small radius (R less than or similar to 70 nm) lase into the HE11 mode, thicker nanowires (70 nm less than or similar to R less than or similar to 90 nm) lase into the TE01 mode.
C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA.
ELORET Corp, Sunnyvale, CA 94085 USA.
RP Maslov, AV (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA.
EM amaslov@nas.nasa.gov; cning@mail.arc.nasa.gov
RI Maslov, Alexey/E-5158-2011; Ning, C. Z./D-4699-2009
OI Maslov, Alexey/0000-0002-7835-2474; Ning, C. Z./0000-0003-4583-8889
NR 23
TC 78
Z9 79
U1 2
U2 19
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9197
J9 IEEE J QUANTUM ELECT
JI IEEE J. Quantum Electron.
PD OCT
PY 2004
VL 40
IS 10
BP 1389
EP 1397
DI 10.1109/JQE.2004.834767
PG 9
WC Engineering, Electrical & Electronic; Optics; Physics, Applied
SC Engineering; Optics; Physics
GA 856RS
UT WOS:000224063100005
ER
PT J
AU Liszka, KJ
Mackin, MA
Lichter, M
York, DW
Pillai, D
Rosenbaum, DS
AF Liszka, KJ
Mackin, MA
Lichter, M
York, DW
Pillai, D
Rosenbaum, DS
TI Keeping a beat on the heart
SO IEEE PERVASIVE COMPUTING
LA English
DT Article
C1 Univ Akron, Akron, OH 44325 USA.
NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
Case Western Reserve Univ, Cleveland, OH 44106 USA.
RP Liszka, KJ (reprint author), Univ Akron, CAS 227, Akron, OH 44325 USA.
EM liszka@computer.org; michael.a.mackin@nasa.gov;
michael.j.lichter@grc.nasa.gov; david.w.york@nasa.gov;
dpillai@metrohealth.org; drosenbaum@metrohealth.org
NR 6
TC 37
Z9 37
U1 0
U2 1
PU IEEE COMPUTER SOC
PI LOS ALAMITOS
PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA
SN 1536-1268
J9 IEEE PERVAS COMPUT
JI IEEE Pervasive Comput.
PD OCT-DEC
PY 2004
VL 3
IS 4
BP 42
EP 49
DI 10.1109/MPRV.2004.10
PG 8
WC Computer Science, Information Systems; Engineering, Electrical &
Electronic; Telecommunications
SC Computer Science; Engineering; Telecommunications
GA 870ST
UT WOS:000225079000011
ER
PT J
AU Howard, A
Seraji, H
AF Howard, A
Seraji, H
TI Multi-sensor terrain classification for safe spacecraft-landing
SO IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS
LA English
DT Article
AB A novel multi-sensor information fusion methodology for intelligent terrain classification is presented. The focus of this research is to analyze safety characteristics of the terrain using imagery data obtained by on-board sensors during spacecraft descent. This information can be used to enable the spacecraft to land safely on a planetary surface. The focus of our approach is on robust terrain analysis and information fusion in which the terrain is analyzed using multiple sensors and the extracted terrain characteristics are combined to select safe landing sites for touchdown. The novelty of this method is the. incorporation of the T-Hazard Map, a multi-valued map representing the, risk associated with landing on a planetary surface. The fusion method is explained in detail in this paper and computer simulation results are presented to validate the approach.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Howard, A (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 198-219, Pasadena, CA 91109 USA.
NR 13
TC 19
Z9 22
U1 0
U2 1
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9251
J9 IEEE T AERO ELEC SYS
JI IEEE Trans. Aerosp. Electron. Syst.
PD OCT
PY 2004
VL 40
IS 4
BP 1122
EP 1131
DI 10.1109/TAES.2004.1386868
PG 10
WC Engineering, Aerospace; Engineering, Electrical & Electronic;
Telecommunications
SC Engineering; Telecommunications
GA 891HO
UT WOS:000226572100001
ER
PT J
AU Basdogan, I
Milman, M
AF Basdogan, I
Milman, M
TI Space interferometry mission instrument model and astrometric
performance validation
SO IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS
LA English
DT Article
AB The Space Interferometry Mission (SIM), will perform very accurate astrometric measurements to measure the positions of stars using a 10 m baseline optical interferometer. The lack of signal from the science targets precludes using the star as a feedback signal to control the science interferometer delay line. In order to solve this problem SIM uses pathlength feed forward (PFF) control of the science interferometer. In the case of controlling the science interferometer optical path, the information to position the science delay line comes from a combination of internal metrology, external metrology, and guide interferometer measurements. The accuracy of the internal and external metrology measurements and the guide interferometer measurements are important for the quality of the feed forward signal and also for the ultimate astrometric performance of the instrument.
An instrument model of SIM has been built to evaluate optical performance and to emulate various observational scenarios. I The effect of averaging methods to reduce metrology cyclic error and the viability of on-orbit calibration maneuvers are studied. The model consists of a real-time dynamics formulation of the spacecraft and a real-time attitude control system. Simulation. results investigate the sensitivity of the feed forward signal to the various error sources and time-varying terms.
C1 Koc Univ, Dept Mech Engn, Coll Engn, TR-80910 Istanbul, Turkey.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Basdogan, I (reprint author), Koc Univ, Dept Mech Engn, Coll Engn, TR-80910 Istanbul, Turkey.
EM ibasdogan@ku.edu.tr
NR 14
TC 1
Z9 1
U1 0
U2 1
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9251
J9 IEEE T AERO ELEC SYS
JI IEEE Trans. Aerosp. Electron. Syst.
PD OCT
PY 2004
VL 40
IS 4
BP 1228
EP 1238
DI 10.1109/TAES.2004.1386876
PG 11
WC Engineering, Aerospace; Engineering, Electrical & Electronic;
Telecommunications
SC Engineering; Telecommunications
GA 891HO
UT WOS:000226572100009
ER
PT J
AU Entekhabi, D
Njoku, EG
Houser, P
Spencer, M
Doiron, T
Kim, YJ
Smith, J
Girard, R
Belair, S
Crow, W
Jackson, TJ
Kerr, YH
Kimball, JS
Koster, R
McDonald, KC
O'Neill, PE
Pultz, T
Running, SW
Shi, JC
Wood, E
van Zyl, J
AF Entekhabi, D
Njoku, EG
Houser, P
Spencer, M
Doiron, T
Kim, YJ
Smith, J
Girard, R
Belair, S
Crow, W
Jackson, TJ
Kerr, YH
Kimball, JS
Koster, R
McDonald, KC
O'Neill, PE
Pultz, T
Running, SW
Shi, JC
Wood, E
van Zyl, J
TI The hydrosphere state (Hydros) satellite mission: An earth system
pathfinder for global mapping of soil moisture and land freeze/thaw
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article; Proceedings Paper
CT 23rd International Geoscience and Remote Sensing Symposium (IGARSS 2003)
CY JUL 21-25, 2003
CL TOULOUSE, FRANCE
SP IEE, IEEE Geosci & Remote Sensing Soc, Ctr Natl Etudes Spatiales, NASA, Natl Ocean & Atmospher Adm, US Dept Commerce, Off Naval Res, eesa, NPOESS, NASDA, Ball Aerosp & Technol Corp, uRSi
DE land freeze/thaw; microwave remote sensing; satellites; soil moisture
ID SPRUCE/MOSS BOREAL FOREST; DATA ASSIMILATION; WATER-CONTENT;
SURFACE-ROUGHNESS; EMPIRICAL-MODEL; CARBON BALANCE; RADAR; SAR;
SCATTEROMETER; SENSITIVITY
AB The Hydrosphere State Mission (Hydros) is a pathfinder mission in the National Aeronautics and Space Administration (NASA) Earth System Science Pathfinder Program (ESSP). The objective of the mission is to provide exploratory global measurements of the earth's soil moisture at 10-km resolution with two- to three-days revisit and land-surface freeze/thaw conditions at 3-km resolution with one- to two-days revisit. The, mission builds on the heritage of ground-based and airborne passive and active low-frequency microwave measurements that have demonstrated and validated the effectiveness of the measurements and associated algorithms for estimating the amount and phase (frozen or thawed) of surface soil moisture. The mission data will enable advances in weather and climate prediction and in mapping processes that link the water, energy, and carbon cycles. The Hydros instrument is a combined radar and radiometer system operating at 1.26 GHz (with VV, HH, and HV polarizations) and 1.41 GHz (with H, V, and U polarizations), respectively. The radar and the radiometer share the aperture of a 6-m antenna with a look-angle of 39degrees with respect to nadir. The lightweight deployable mesh antenna is rotated at 14.6 rpm to provide a constant look-angle scan across a swath width of 1000 km. The wide swath provides global coverage that meet the revisit requirements. The radiometer measurements allow retrieval of soil moisture in diverse (nonforested) landscapes with a resolution of 40 km. The radar measurements allow the retrieval of soil moisture at relatively high resolution (3 km). The mission includes combined radar/radiometer data products that will use the synergy of the two sensors to deliver enhanced-quality 10-km resolution soil moisture estimates. In this paper, the science requirements and their traceability to the instrument design are outlined. A review of the underlying measurement physics and key instrument performance parameters are also presented.
C1 MIT, Dept Civil & Environm Engn, Cambridge, MA 02139 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA.
Canadian Space Agcy, St Hubert, PQ J3Y 8Y9, Canada.
Meteorol Serv Canada, Dorval, PQ H98 1J3, Canada.
USDA ARS, Hydrol & Remote Sensing Lab, Beltsville, MD 20705 USA.
Ctr Etudes Spatiales Biosphere, F-31401 Toulouse 09, France.
Univ Montana, Div Biol Sci, Polson, MT 59860 USA.
Canada Ctr Remote Sensing, Natl Resources Canada, Ottawa, ON K1A 0Y7, Canada.
Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA.
Princeton Univ, Dept Civil & Environm Engn, Piscataway, NJ 08854 USA.
RP Entekhabi, D (reprint author), MIT, Dept Civil & Environm Engn, 77 Massachusetts Ave, Cambridge, MA 02139 USA.
EM darae@mit.edu
RI Koster, Randal/F-5881-2012; O'Neill, Peggy/D-2904-2013; Houser,
Paul/J-9515-2013;
OI Koster, Randal/0000-0001-6418-6383; Houser, Paul/0000-0002-2991-0441;
Wood, Eric/0000-0001-7037-9675
NR 53
TC 137
Z9 139
U1 4
U2 29
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD OCT
PY 2004
VL 42
IS 10
BP 2184
EP 2195
DI 10.1109/TGRS.2004.834631
PG 12
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 863ZP
UT WOS:000224602600018
ER
PT J
AU Font, J
Lagerloef, GSE
Le Vine, DM
Camps, A
Zanife, OZ
AF Font, J
Lagerloef, GSE
Le Vine, DM
Camps, A
Zanife, OZ
TI The determination of surface salinity with the European SMOS space
mission
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article; Proceedings Paper
CT 23rd International Geoscience and Remote Sensing Symposium (IGARSS 2003)
CY JUL 21-25, 2003
CL TOULOUSE, FRANCE
SP IEE, IEEE Geosci & Remote Sensing Soc, Ctr Natl Etudes Spatiales, NASA, Natl Ocean & Atmospher Adm, US Dept Commerce, Off Naval Res, eesa, NPOESS, NASDA, Ball Aerosp & Technol Corp, uRSi
DE microwave radiometry; oceanography; salinity
ID POLARIMETRIC THERMAL EMISSION; L-BAND; OCEAN SALINITY; SOIL-MOISTURE;
SEA-FOAM; INTERFEROMETRIC RADIOMETRY; BRIGHTNESS TEMPERATURES;
MICROWAVE-FREQUENCIES; SCATTERING MODEL; WIND-SPEED
AB The European Space Agency Soil Moisture and Ocean Salinity (SMOS) mission aims at obtaining global maps of soil moisture and sea surface salinity from space for large-scale and climatic studies. It uses an L-band (1400-1427 MHz) Microwave Interferometric Radiometer by Aperture Synthesis to measure brightness temperature of the earth's surface at horizontal and vertical polarizations (T-h and T-v). These two parameters will be used together to retrieve the geophysical parameters. The retrieval of salinity is a complex process that requires the knowledge of other environmental information and an accurate processing of the radiometer measurements. Here, we present recent results obtained from several studies and field experiments that were part of the SMOS mission, and highlight the issues still to be solved.
C1 CSIC, CMIMA, Inst Ciencias Mar, Barcelona 08003, Spain.
Earth & Space Res, Seattle, WA 98102 USA.
NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Microwave Sensors Branch, Greenbelt, MD 20771 USA.
Univ Politecn Cataluna, Dept Teor Senyal & Comun, ES-08034 Barcelona, Spain.
Space Oceanog Div, F-31526 Ramonville St Agne, France.
RP CSIC, CMIMA, Inst Ciencias Mar, Barcelona 08003, Spain.
EM jfont@icm.csic.es; lager@esr.org; David.M.LeVine@nasa.gov
RI Font, Jordi/E-5355-2013; Camps, Adriano/D-2592-2011
OI Font, Jordi/0000-0003-2590-1457; Camps, Adriano/0000-0002-9514-4992
NR 69
TC 96
Z9 102
U1 0
U2 3
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0196-2892
EI 1558-0644
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD OCT
PY 2004
VL 42
IS 10
BP 2196
EP 2205
DI 10.1109/TGRS.2004.834649
PG 10
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 863ZP
UT WOS:000224602600019
ER
PT J
AU Wei, HL
Yang, P
Li, J
Baum, BA
Huang, HL
Platnick, S
Hu, YX
Strow, L
AF Wei, HL
Yang, P
Li, J
Baum, BA
Huang, HL
Platnick, S
Hu, YX
Strow, L
TI Retrieval of semitransparent ice cloud optical thickness from
atmospheric infrared sounder (AIRS) measurements
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE Atmospheric Infrared Sounder (AIRS); ice clouds; infrared radiation
transfer; optical thickness; retrieval
ID SINGLE-SCATTERING PROPERTIES; CIRRUS CLOUD; RADIATIVE PROPERTIES;
LIGHT-SCATTERING; WINDOW REGION; WATER-VAPOR; SENSITIVITY; AIRCRAFT;
MODIS; TEMPERATURE
AB An approach is developed to infer the optical thickness of semitransparent ice clouds (when optical thickness is less than 5) from Atmospheric Infrared Sounder (AIRS) high spectral resolution radiances. A fast cloud radiance model is developed and coupled with an AIRS clear-sky radiative transfer model for simulating AIRS radiances when ice clouds are present. Compared with more accurate calculations based on the discrete ordinates radiative transfer model, the accuracy of the fast cloud radiance model is within 0.5 K (root mean square) in terms of brightness temperature (BT) and runs three orders of magnitude faster. We investigate the sensitivity of AIRS spectral BTs and brightness temperature difference (BTD) values between pairs of wavenumbers to the cloud optical thickness. The spectral BTs for the atmospheric window channels within the region 1070-1135 cm(-1) are sensitive to the ice cloud optical thickness, as is the BTD between 900.562 cm(-1) (located in an atmospheric window) and 1558.692 cm(-1) (located in a strong water vapor absorption band). Similarly, the BTD between a moderate absorption channel (1587.495 cm(-1)) and the strong water absorption channel (1558.692 cm(-1)) is sensitive to ice cloud optical thickness. Neither of the aforementioned BTDs is sensitive to the effective particle size. Thus, the optical thickness of semitransparent ice clouds can be retrieved reliably. We have developed a spectrum-based approach and a BTD-based method to retrieve the optical thickness of semitransparent ice clouds. The present retrieval methods are applied to a granule of AIRS data. The ice cloud optical thicknesses derived from the AIRS measurements are compared with those retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) 1.38- and 0.645-mum bands. The optical thicknesses inferred from the MODIS measurements are collocated and degraded to the AIRS spatial resolution. Results from the MODIS and AIRS retrievals are in reasonable agreement over a wide range of optical thicknesses.
C1 Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA.
Univ Wisconsin, Cooperat Inst Meteorol Satelite Studies, Madison, WI 53706 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA.
RP Wei, HL (reprint author), Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA.
EM pyang@ariel.met.tamu.edu
RI Yang, Ping/B-4590-2011; Baum, Bryan/B-7670-2011; Platnick,
Steven/J-9982-2014; Hu, Yongxiang/K-4426-2012; Li, Jun/H-3579-2015
OI Baum, Bryan/0000-0002-7193-2767; Platnick, Steven/0000-0003-3964-3567;
Li, Jun/0000-0001-5504-9627
NR 54
TC 67
Z9 69
U1 1
U2 9
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD OCT
PY 2004
VL 42
IS 10
BP 2254
EP 2267
DI 10.1109/TGRS.2004.833780
PG 14
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 863ZP
UT WOS:000224602600025
ER
PT J
AU Siegel, PH
AF Siegel, PH
TI Terahertz technology in biology and medicine
SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
LA English
DT Article
DE applications; biology; medicine; technology; terahertz
ID TIME-DOMAIN SPECTROSCOPY; AVIDIN-BIOTIN BINDING; PULSE SPECTROSCOPY;
VIBRATIONAL-MODES; POLAR LIQUIDS; ALL-TRANS; THZ; SKIN; DNA; RADIATION
AB Terahertz irradiation and sensing is being applied for the first time to a wide range of fields outside the traditional niches of space science, molecular line spectroscopy, and plasma diagnostics. This paper surveys some of the terahertz measurements and applications of interest in the biological and medical sciences.
C1 CALTECH, Div Biol, Pasadena, CA 91125 USA.
CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA.
RP Siegel, PH (reprint author), CALTECH, Div Biol, Pasadena, CA 91125 USA.
EM phs@caltech.edu
NR 83
TC 497
Z9 510
U1 19
U2 132
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9480
J9 IEEE T MICROW THEORY
JI IEEE Trans. Microw. Theory Tech.
PD OCT
PY 2004
VL 52
IS 10
BP 2438
EP 2447
DI 10.1109/TMTT.2004.83516
PG 10
WC Engineering, Electrical & Electronic
SC Engineering
GA 860GQ
UT WOS:000224330900014
ER
PT J
AU Khanna, SM
Estan, D
Erhardt, LS
Houdayer, A
Carlone, C
Lonascut-Nedelcescu, A
Messenger, SR
Walters, RJ
Summers, GP
Warner, JH
Jun, I
AF Khanna, SM
Estan, D
Erhardt, LS
Houdayer, A
Carlone, C
Lonascut-Nedelcescu, A
Messenger, SR
Walters, RJ
Summers, GP
Warner, JH
Jun, I
TI Proton energy dependence of the light output in gallium nitride
light-emitting diodes
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article; Proceedings Paper
CT 7th European Conference on Radiation and its Effects on Components and
Systems
CY SEP 15-19, 2003
CL Noordwijk, NETHERLANDS
SP European Space Agcy
DE blue LEDs; energy dependence; gallium nitride; light emission
degradation; non-ionizing energy loss (NIEL); optoelectronics; proton;
quantum-well light-emitting diodes; radiation damage
ID RADIATION-DAMAGE
AB Gallium nitride (GaN)-based blue-emitting diodes (CREE Model C430-DH85) were irradiated at room temperature with protons in the energy range 2 to 115 MeV at fluences varying from 1 x 10(11) to 1 x 10(15) cm(-2). Light output degradation curves were obtained for each energy and the damage constant (A) associated with these curves was determined according to the theory of Rose and Barnes. For proton energies less than 10 MeV, A varies inversely with the proton energy (E). At higher energies, A is consistently above the 1 / E relationship. The change in nature of the energy dependence is attributed to nuclear interactions. Nonionizing energy loss calculations for the case of protons on GaN are presented. Good agreement between theory and experiment is obtained.
C1 Def Res Estab, Ottawa, ON K1A 0Z4, Canada.
Univ Montreal, Dept Phys, Montreal, PQ, Canada.
Univ Sherbrooke, Dept Phys, Sherbrooke, PQ J1K 2R1, Canada.
SFA Inc, Largo, MD 20774 USA.
USN, Res Lab, Washington, DC 20375 USA.
Univ Maryland Baltimore Cty, Baltimore, MD 21250 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Khanna, SM (reprint author), Def Res Estab, Ottawa, ON K1A 0Z4, Canada.
EM shyam.khanna@drdc-rddc.gc.ca; houdayera@lps.umontreal.ca;
carlone@physique.usherb.ca; messenger@nrl.navy.mil;
rwalters@ccf.nrl.navy.mil; gsummers@umbc.edu; warnerj@estd.nrl.navy.mil;
Insoo.Jun@jpl.nasa.gov
NR 14
TC 16
Z9 16
U1 0
U2 5
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD OCT
PY 2004
VL 51
IS 5
BP 2729
EP 2735
DI 10.1109/TNS.2004.835097
PN 3
PG 7
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 862LE
UT WOS:000224491400003
ER
PT J
AU Marshall, PW
Wiley, PT
Prusia, RN
Rash, GD
Kim, H
LaBel, KA
AF Marshall, PW
Wiley, PT
Prusia, RN
Rash, GD
Kim, H
LaBel, KA
TI Proton-induced bit error studies in a 10 Gb/s fiber optic link
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article; Proceedings Paper
CT 7th European Conference on Radiation and its Effects on Components and
Systems
CY SEP 15-19, 2003
CL Noordwijk, NETHERLANDS
SP European Space Agcy
DE optical receivers; proton radiation effects
AB We describe a stand-alone experiment with autonomous error checking and logging used to acquire proton-induced bit error response of a 10 Gb/s multimode fiber optic data link operating over a 100-m fiber length. Comparisons with previously tested lower data rate data links indicate the primary source of bit errors arise in the link receiver's photodiode. The serial 10 Gb/s results show relatively lower bit error rate (BER) sensitivity to 63 MeV protons. Proton BER results of supporting high-speed bipolar multiplexer and demultiplexer circuitry are also presented.
C1 NASA, Goddard Space Flight Ctr, Brookneal, VA 24528 USA.
China Lake Naval Air Stn, China Lake, CA 93555 USA.
Mayo Clin & Mayo Fdn, Rochester, MN 55905 USA.
Jackson & Tull Chartered Engineers, Washington, DC 20018 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Marshall, PW (reprint author), NASA, Goddard Space Flight Ctr, Brookneal, VA 24528 USA.
EM pwmarshall@aol.com; wileypt@navair.navy.mil; ronald.prusia@navy.mil
NR 5
TC 5
Z9 5
U1 0
U2 1
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD OCT
PY 2004
VL 51
IS 5
BP 2736
EP 2739
DI 10.1109/TNS.2004.836527
PN 3
PG 4
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 862LE
UT WOS:000224491400004
ER
PT J
AU Koga, R
George, J
Swift, G
Yui, C
Edmonds, L
Carmichael, C
Langley, T
Murray, P
Lanes, K
Napier, M
AF Koga, R
George, J
Swift, G
Yui, C
Edmonds, L
Carmichael, C
Langley, T
Murray, P
Lanes, K
Napier, M
TI Comparison of Xilinx Virtex-II FPGA SEE sensitivities to protons and
heavy ions
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article; Proceedings Paper
CT 7th European Conference on Radiation and its Effects on Components and
Systems
CY SEP 15-19, 2003
CL Noordwijk, NETHERLANDS
SP European Space Agcy
DE field programmable gate array (FPGA); heavy ion radiation effects;
proton radiation effects; semiconductor device testing; single event
effects
ID UPSET; MODEL; RATES
AB A comparison of heavy-ion and proton-induced single event effect sensitivities has been made using the Xilinx Virtex-II field programmable gate array (FPGA). Recently fabricated test samples are selected for observations of single event upset and single event functional interrupt. A complex relationship appears to exist between the heavy ion and proton sensitivities due to effects such as multiple-bit upsets and elastic nuclear scattering.
C1 Aerosp Corp, El Segundo, CA 90245 USA.
Jet Prop Lab, Pasadena, CA 91109 USA.
Xilinx, San Jose, CA USA.
SEAKR Engn, Centennial, CO 80111 USA.
Sandia Natl Labs, Albuquerque, NM 87123 USA.
RP Koga, R (reprint author), Aerosp Corp, El Segundo, CA 90245 USA.
EM rocky.koga@aero.org; gary.swift@jpl.nasa.gov; carlc@xilinx.com;
tlangley@seakr.com; krlanes@sandia.gov
NR 24
TC 31
Z9 33
U1 0
U2 8
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD OCT
PY 2004
VL 51
IS 5
BP 2825
EP 2833
DI 10.1109/TNS.2004.835057
PN 3
PG 9
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 862LE
UT WOS:000224491400018
ER
PT J
AU Buchner, S
Carts, MA
McMorrow, D
Kim, H
Marshall, PW
LaBel, KA
AF Buchner, S
Carts, MA
McMorrow, D
Kim, H
Marshall, PW
LaBel, KA
TI Characteristics of single-event upsets in a fabric switch (AD8151)
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article; Proceedings Paper
CT 7th European Conference on Radiation and its Effects on Components and
Systems
CY SEP 15-19, 2003
CL Noordwijk, NETHERLANDS
SP European Space Agcy
DE bit errors; fabric switch; heavy ions; pulsed laser; single-event
functional interrupt
AB Two types of single-event effects-bit errors and single-event functional interrupts-were observed during heavy-ion testing of the AD8151 crosspoint switch. Bit errors occurred in bursts with the average number of bits in a burst being dependent on both the ion linear energy transfer (LET) and on the data rate. A pulsed laser was used to identify the locations on the chip where the bit errors and single-event functional interrupts occurred. Bit errors originated in the switches, drivers, and output buffers. Single-event functional interrupts originated in the second-rank latch containing the data specifying the state of each switch in the 33 x 17 matrix.
C1 QSS Grp Inc, Seabrook, MD 20706 USA.
Raytheon Syst Corp, Lanham, MD 20706 USA.
USN, Res Lab, Washington, DC 20375 USA.
Jackson & Tull Chartered Engn, Washington, DC 20018 USA.
NASA GSFC, Brookneal, VA 24528 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Buchner, S (reprint author), QSS Grp Inc, Seabrook, MD 20706 USA.
EM sbuchner@pop500.gsfc.nasa.gov; mcarts@pop500.gsfc.nasa.gov;
mcmorrow@ccs.nrl.navy.mil; hkim@pop700.gsfc.nasa.gov;
pwmarshall@aol.com; Kenneth.A.LaBel@nasa.gov
NR 2
TC 0
Z9 0
U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD OCT
PY 2004
VL 51
IS 5
BP 2840
EP 2845
DI 10.1109/TNS.2004.835085
PN 3
PG 6
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 862LE
UT WOS:000224491400020
ER
PT J
AU Messenger, SR
Burke, EA
Xapsos, MA
Summers, GP
Walters, RJ
AF Messenger, SR
Burke, EA
Xapsos, MA
Summers, GP
Walters, RJ
TI The simulation of damage tracks in silicon
SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE
LA English
DT Article; Proceedings Paper
CT 7th European Conference on Radiation and its Effects on Components and
Systems
CY SEP 15-19, 2003
CL Noordwijk, NETHERLANDS
SP European Space Agcy
DE displacement damage; nonionizing energy loss (NIEL); nuclear stopping
power; Ziegler-Biersack-Littmark (ZBL) screened potential
ID RANGE DISTRIBUTIONS; ENERGY; IONS; NIEL; PARTICLES
AB We describe an analytical model for deriving heavy ion damage tracks using nonionizing energy loss (NIEL) and range-energy relations. NIEL is directly calculated for heavy ions based upon screened Coulomb potentials in the nonrelativistic limit and the projected range algorithm (PRAL) is used to obtain the range relationship. Examples of damage track calculations are given for incident ions on silicon.
C1 SFA Inc, Largo, MD 20774 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
USN, Res Lab, Washington, DC 20375 USA.
Univ Maryland Baltimore Cty, Baltimore, MD 21250 USA.
RP Messenger, SR (reprint author), SFA Inc, Largo, MD 20774 USA.
EM messenger@nrl.navy.mil; edaburke@rcn.com; Michael.A.Xapsos@nasa.gov;
gsummers@umbc.edu; rwalters@ccf.nrl.navy.mil
NR 13
TC 2
Z9 2
U1 1
U2 4
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9499
J9 IEEE T NUCL SCI
JI IEEE Trans. Nucl. Sci.
PD OCT
PY 2004
VL 51
IS 5
BP 2846
EP 2850
DI 10.1109/TNS.2004.835094
PN 3
PG 5
WC Engineering, Electrical & Electronic; Nuclear Science & Technology
SC Engineering; Nuclear Science & Technology
GA 862LE
UT WOS:000224491400021
ER
PT J
AU Gatsonis, NA
Byrne, LT
Zwahlen, JC
Pencil, EJ
Kamhawi, H
AF Gatsonis, NA
Byrne, LT
Zwahlen, JC
Pencil, EJ
Kamhawi, H
TI Current-mode triple and quadruple Langmuir probe methods with
applications to flowing pulsed plasmas
SO IEEE TRANSACTIONS ON PLASMA SCIENCE
LA English
DT Article
DE double probe; flowing plasma measurements; pulsed plasma measurements;
quadruple Langmuir probe; triple Langmuir probe
ID HIGH-PRESSURE PLASMA; ELECTROSTATIC PROBES; THRUSTER; PLUME; ARCJET
AB A current-mode method for triple and quadruple Langmuir probes was developed and implemented in flowing, pulsed, collisionless plasmas. The current-mode method involves biasing all probe electrodes, and requires the measurement of probe currents providing the electron temperature, the electron density, and the ratio of ion speed to most probable thermal speed. The current-mode theory is developed for a single species, two-temperature, collisionless plasma. The current collection model for a probe aligned with the flow and radius to Debye length ratios of 5 less than or equal to r(p) / lambda(D) less than or equal to 100 accounts for finite-sheath effects while for r(p) / lambda(D) > 100, current collection is based on the thin-sheath assumption. The ion current to the perpendicular probe assumes a thin-sheath and is given as a function of the ion speed ratio. The numerical procedure for the solution of the nonlinear current-mode equations, as well sensitivity and uncertainty analysis are presented. The plasma source used in the experiments is a laboratory Teflon pulsed plasma thruster, operating at discharge energies of 5, 20, and 40 J, with a pulse duration of 10-15 mus, ablating 20-50 mug/pulse. Current-mode triple and quadruple probe measurements obtained at various locations in the plume of the plasma source are presented. Extensive comparisons between double probe and current-mode probe measurements validate the new method.
C1 Worcester Polytech Inst, Dept Mech Engn, Worcester, MA 01609 USA.
NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Gatsonis, NA (reprint author), Worcester Polytech Inst, Dept Mech Engn, Worcester, MA 01609 USA.
EM gatsonis@wpi.edu
NR 30
TC 16
Z9 18
U1 0
U2 11
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0093-3813
J9 IEEE T PLASMA SCI
JI IEEE Trans. Plasma Sci.
PD OCT
PY 2004
VL 32
IS 5
BP 2118
EP 2129
DI 10.1109/TPS.2004.835520
PN 2
PG 12
WC Physics, Fluids & Plasmas
SC Physics
GA 863NB
UT WOS:000224567500008
ER
PT J
AU Powell, MW
Sarkar, S
Goldgof, DB
Ivanov, K
AF Powell, MW
Sarkar, S
Goldgof, DB
Ivanov, K
TI A methodology for extracting objective color from images
SO IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART B-CYBERNETICS
LA English
DT Article
DE burn scars; color calibration; color correction; computer vision; image
processing; light calibration; range images; realistic re-endering; skin
color
ID RANGE IMAGES; REFLECTANCE; SEGMENTATION; CONSTANCY; REGIONS; MODEL
AB We present a methodology for correcting color images taken in practical indoor environments, such as laboratories, factories, and studios, that explicitly models illuminant location, surface reflectance and geometry, and camera responsivity. We explicitly model surfaces by taking our color images with corresponding registered three-dimensional (3-D) range images, which provide surface orientation and location information for every point in the scene. We automatically detect regions where color correction should not be applied, such as specularities, coarse texture regions, and jump edges. This correction results in objective color measures of the imaged surfaces. This kind of integrated, comprehensive system of color correction has not existed until now. i.e., it is the first of its kind in computer vision. We demonstrate results of applying this methodology to real images for applications in photorealistic rerendering, skin lesion detection, burn scar color measurement, and general color image enhancement. We also have tested the method under different lighting configurations and with three different range scanners.
C1 Jet Prop Lab, Mobil Syst Concept Dev Sect, Pasadena, CA 91109 USA.
Univ S Florida, Dept Comp Sci & Engn, Tampa, FL 33620 USA.
Univ S Florida, Dept Comp Sci & Engn, Tampa, FL 33620 USA.
Verizon Serv Grp, Tampa, FL 33637 USA.
RP Powell, MW (reprint author), Jet Prop Lab, Mobil Syst Concept Dev Sect, Pasadena, CA 91109 USA.
EM mpowell@csee.usf.edu; sarkar@csee.usf.edu; goldgof@csee.usf.edu;
kivanov@csee.usf.edu
RI Sarkar, Sudeep/A-8213-2009
OI Sarkar, Sudeep/0000-0001-7332-4207
NR 25
TC 10
Z9 10
U1 0
U2 4
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 1083-4419
J9 IEEE T SYST MAN CY B
JI IEEE Trans. Syst. Man Cybern. Part B-Cybern.
PD OCT
PY 2004
VL 34
IS 5
BP 1964
EP 1978
DI 10.1109/TSMCB.2004.832177
PG 15
WC Automation & Control Systems; Computer Science, Artificial Intelligence;
Computer Science, Cybernetics
SC Automation & Control Systems; Computer Science
GA 854XO
UT WOS:000223937400003
PM 15503493
ER
PT J
AU Wang, XF
Lou, DYS
Zhang, NL
AF Wang, XF
Lou, DYS
Zhang, NL
TI A helical tow model and numerical simulation of on-line thermal curing
of thermoset composites in filament winding
SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
LA English
DT Article
DE helical tow model; curing; filament winding; numerical grid generation;
anisotropic medium
ID PIPE-FLOW; NUMBER; CURE; HEAT
AB A helical tow model of on-line curing of thermoset composites in winding is developed and solved numerically. Actual shape of tow in winding process is considered, and consequently, the modeling of the on-line curing process is more realistic. A numerical grid generation method is developed for the complicated geometry. Transformations of three-dimensional energy equation and its boundary conditions from physical domain to computational domain are performed, which are crucial in numerical grid generation method when an anisotropic medium is involved. A set of concise and regular equations is obtained. The numerical simulation results show that the helical tow model, in stead of a simplified model, should be used when the ratio of the diameter of fiber-wound composite structure to the diameter of tow is small. (C) 2004 Elsevier Ltd. All rights reserved.
C1 NASA, Glenn Res Ctr, Micrograv Sci Div, Lewis Field, Cleveland, OH 44135 USA.
Univ Nebraska, Dept Mech Engn, Lincoln, NE 68588 USA.
RP Zhang, NL (reprint author), NASA, Glenn Res Ctr, Micrograv Sci Div, Lewis Field, 21000 Brookpk Rd, Cleveland, OH 44135 USA.
EM nengli.zhang@gr.nasa.gov
NR 27
TC 4
Z9 5
U1 0
U2 2
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0017-9310
J9 INT J HEAT MASS TRAN
JI Int. J. Heat Mass Transf.
PD OCT
PY 2004
VL 47
IS 22
BP 4807
EP 4820
DI 10.1016/j.ijheatmasstransfer.2004.05.010
PG 14
WC Thermodynamics; Engineering, Mechanical; Mechanics
SC Thermodynamics; Engineering; Mechanics
GA 855UZ
UT WOS:000224001700012
ER
PT J
AU Johnson, W
Liao, MJ
Granada, S
AF Johnson, W
Liao, MJ
Granada, S
TI Effects of relative brightness highlighting on target detection
performance in a cockpit display of traffic information
SO INTERNATIONAL JOURNAL OF PSYCHOLOGY
LA English
DT Meeting Abstract
C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
San Jose State Univ, San Jose, CA 95192 USA.
NR 0
TC 2
Z9 2
U1 0
U2 0
PU PSYCHOLOGY PRESS
PI HOVE
PA 27 CHURCH RD, HOVE BN3 2FA, EAST SUSSEX, ENGLAND
SN 0020-7594
J9 INT J PSYCHOL
JI Int. J. Psychol.
PD OCT-DEC
PY 2004
VL 39
IS 5-6
SU S
BP 3
EP 3
PG 1
WC Psychology, Multidisciplinary
SC Psychology
GA 884WS
UT WOS:000226118000020
ER
PT J
AU Liao, MJ
Johnson, W
Granada, S
AF Liao, MJ
Johnson, W
Granada, S
TI The influence of symbol brightness on eye movements within a cockpit
display of traffic information
SO INTERNATIONAL JOURNAL OF PSYCHOLOGY
LA English
DT Meeting Abstract
C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
San Jose State Univ Fdn, San Jose, CA USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
NR 0
TC 0
Z9 0
U1 0
U2 0
PU PSYCHOLOGY PRESS
PI HOVE
PA 27 CHURCH RD, HOVE BN3 2FA, EAST SUSSEX, ENGLAND
SN 0020-7594
J9 INT J PSYCHOL
JI Int. J. Psychol.
PD OCT-DEC
PY 2004
VL 39
IS 5-6
SU S
BP 3
EP 3
PG 1
WC Psychology, Multidisciplinary
SC Psychology
GA 884WS
UT WOS:000226118000025
ER
PT J
AU Figueras, D
Karnieli, A
Brenner, A
Kaufman, YJ
AF Figueras, D
Karnieli, A
Brenner, A
Kaufman, YJ
TI Masking turbid water in the southeastern Mediterranean Sea utilizing the
SeaWiFS 510 nm spectral band
SO INTERNATIONAL JOURNAL OF REMOTE SENSING
LA English
DT Article
ID BAY
AB A simplified model for masking water turbidity in the southeastern Mediterranean Sea is suggested and demonstrated using SeaWiFS images. The model is implemented by using a null point at 497 nm ( corresponding to SeaWiFS band 4 centred at 510 nm) where the level of reflectance is not affected by change in chlorophyll concentration. Any shift of reflectance above the null point indicates suspended matter present in the water. Masking of pixels with values above the threshold results in elimination of the turbidity. The 510 nm null point can also be used for calculating suspended matter concentrations in the area, since it defines the effects of suspended matter on the spectrum.
C1 Ben Gurion Univ Negev, Jacob Blaustein Inst Desert Res, Remote Sensing Lab, IL-84990 Sede Boqer, Israel.
Ben Gurion Univ Negev, Dept Environm Engn, IL-84105 Beer Sheva, Israel.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Karnieli, A (reprint author), Ben Gurion Univ Negev, Jacob Blaustein Inst Desert Res, Remote Sensing Lab, Sede Boker Campus, IL-84990 Sede Boqer, Israel.
EM karnieli@bgumail.bgu.ac.il
RI Brenner, Asher/B-4478-2012
NR 15
TC 4
Z9 4
U1 0
U2 0
PU TAYLOR & FRANCIS LTD
PI ABINGDON
PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND
SN 0143-1161
J9 INT J REMOTE SENS
JI Int. J. Remote Sens.
PD OCT
PY 2004
VL 25
IS 19
BP 4051
EP 4059
DI 10.1080/01431160310001657498
PG 9
WC Remote Sensing; Imaging Science & Photographic Technology
SC Remote Sensing; Imaging Science & Photographic Technology
GA 851AQ
UT WOS:000223657100018
ER
PT J
AU Gawronski, W
Ahlstrom, HG
Bernardo, AM
AF Gawronski, W
Ahlstrom, HG
Bernardo, AM
TI Analysis and performance of the control systems of the NASA 70-meter
antennas
SO ISA TRANSACTIONS
LA English
DT Article
DE control systems; control engineering; antenna; radiotelescope
ID H-INFINITY; TELESCOPE; DESIGN
AB The control systems of the NASA 70-m antennas include the antenna control system, the Master Equatorial (ME) control system, and their combinations (called modes). The Master Equatorial is a small telescope mounted on the top of a tower located inside the antenna structure. In the Antenna Encoder mode antenna encoders are used to close the feedback loop. In the Autocollimator mode the Master Equatorial is a master that follows a target, and the antenna is a slave that follows the Master Equatorial. In the Master Equatorial Encoder mode the "master-slave" relationship is reversed. In the paper the analysis begins with the description of the open-loop models of the antenna and of the Master Equatorial. We obtained the models by using field test data and system identification techniques. Next, we analyzed and evaluated the performance of the three modes of the antenna control system. The analysis showed that the Autocollimator and Master Equatorial Encoder tracking modes are feasible for high-rate tracking, and that the latter mode has the smallest tracking error. Finally, we analyzed the switching between antenna modes, necessary while tracking near the keyhold. We showed that switching causes jerks of magnitudes within the acceptable threshold. The contribution of this paper includes the development of the antenna model using field data and system identification procedures, the development of the LQG control algorithm for the 70-meter antenna, the development of two control cooperating systems (antenna and ME), identifying the more appropriate, and analyzing of switching between the two control systems. (C) 2004 ISA-The Instrumentation, Systems, and Automation Society.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Gawronski, W (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
NR 14
TC 3
Z9 5
U1 0
U2 2
PU I S A-THE INSTRUMENTATION SYSTEMS AUTOMATION SOC
PI RES TRIANGLE PK
PA 67 ALEXANDER DR, PO BOX 12277, RES TRIANGLE PK, NC 27709 USA
SN 0019-0578
J9 ISA T
JI ISA Trans.
PD OCT
PY 2004
VL 43
IS 4
BP 597
EP 610
DI 10.1016/S0019-0578(07)60171-2
PG 14
WC Automation & Control Systems; Engineering, Multidisciplinary;
Instruments & Instrumentation
SC Automation & Control Systems; Engineering; Instruments & Instrumentation
GA 862MJ
UT WOS:000224494700009
PM 15535397
ER
PT J
AU Cantrell, JH
AF Cantrell, JH
TI Determination of absolute bond strength from hydroxyl groups at oxidized
aluminum-epoxy interfaces by angle beam ultrasonic spectroscopy
SO JOURNAL OF APPLIED PHYSICS
LA English
DT Article
ID ADHESIVE JOINTS
AB The hydrogen bonding (H-bond) contribution to the adhesive strength of oxidized aluminum-epoxy interfaces is calculated from the Morse potential for the interaction of hydroxyl groups formed on the Al2O3 surface with epoxy receptors. A strength parameter called the normal spring constant flux K-N is defined and calculated to be 3.8x10(17) N m(-3), corresponding to a tensile strength of 26 MPa, for values of the H-bond parameters and bond densities typical of moderate strength epoxies. The K-N value is in very good agreement with values determined experimentally from an inversion of ultrasonic spectral data [A. I. Laverntyev and S. I. Rokhlin, J. Appl. Phys. 76, 4643 (1994); J. Acoust. Soc. Am. 102, 3467 (1997)]. It is also in agreement with the value K-N=3.6x10(17) N m(-3) obtained by a reinterpretation of the periodic crack model [F. J. Margetan , J. Nondestr. Eval. 7, 131 (1988)] when applied to adhesive interfaces. The agreement between theory and experiment establishes K-N as a quantitative nondestructive measure of adhesive strength. The relationship between the normal and transverse (shear) spring constant fluxes is derived and the effects of thermal fluctuations are addressed. (C) 2004 American Institute of Physics.
C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Cantrell, JH (reprint author), NASA, Langley Res Ctr, Mail Stop 231, Hampton, VA 23681 USA.
NR 30
TC 14
Z9 14
U1 0
U2 4
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0021-8979
J9 J APPL PHYS
JI J. Appl. Phys.
PD OCT 1
PY 2004
VL 96
IS 7
BP 3775
EP 3781
DI 10.1063/1.1787144
PG 7
WC Physics, Applied
SC Physics
GA 857VB
UT WOS:000224145800029
ER
PT J
AU Riley, P
Linker, JA
Lionello, R
Mikic, Z
Odstrcil, D
Hidalgo, MA
Cid, C
Hu, Q
Lepping, RP
Lynch, BJ
Rees, A
AF Riley, P
Linker, JA
Lionello, R
Mikic, Z
Odstrcil, D
Hidalgo, MA
Cid, C
Hu, Q
Lepping, RP
Lynch, BJ
Rees, A
TI Fitting flux ropes to a global MHD solution: a comparison of techniques
SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
LA English
DT Article
DE coronal mass ejection; magnetic cloud; magnetic flux rope;
magnetohydrodynamic simulation; solar wind; sun; heliosphere
ID CORONAL MASS EJECTIONS; SOLAR-WIND; MAGNETOPAUSE TRANSECTS; MAGNETIC
CLOUDS; CONSTANT-ALPHA; SPACECRAFT; FIELD; PROPAGATION
AB Flux rope fitting (FRF) techniques are an invaluable tool for extracting information about the properties of a subclass of coronal mass ejections (CMEs) in the solar wind. However, it has proven difficult to assess their accuracy since the underlying global structure of the CME cannot be independently determined from the data. In contrast, large-scale MHD simulations of CME evolution can provide both a global view as well as localized time series at specific points in space. In this study we apply five different fitting techniques to two hypothetical time series derived from MHD simulation results. Independent teams performed the analysis of the events in ''blind tests", for which no information, other than the time series, was provided. From the results, we infer the following: (1) Accuracy decreases markedly with increasingly glancing encounters; (2) Correct identification of the boundaries of the flux rope can be a significant limiter; and (3) Results from techniques that infer global morphology must be viewed with caution. In spite of these limitations, FRF techniques remain a useful tool for describing in situ observations of flux rope CMEs. (C) 2004 Elsevier Ltd. All rights reserved.
C1 Sci Applicat Int Corp, San Diego, CA 92121 USA.
Univ Colorado, Ctr Integrated Res Environm Sci, Boulder, CO 80305 USA.
NOAA, Space Environm Ctr, Boulder, CO 80304 USA.
Univ Alcala de Henares, Dept Fis, Madrid, Spain.
Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA.
NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA.
Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA.
Univ London Imperial Coll Sci & Technol, Blackett Lab, London SW7 2BW, England.
RP Riley, P (reprint author), Sci Applicat Int Corp, San Diego, CA 92121 USA.
EM pete.riley@saic.com
RI Lynch, Benjamin/B-1300-2013; Hidalgo, Miguel/L-5826-2014;
OI Hidalgo, Miguel/0000-0003-1617-2037; CID, CONSUELO/0000-0002-2863-3745;
Lynch, Benjamin/0000-0001-6886-855X
NR 31
TC 76
Z9 76
U1 0
U2 2
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 1364-6826
J9 J ATMOS SOL-TERR PHY
JI J. Atmos. Sol.-Terr. Phys.
PD OCT-NOV
PY 2004
VL 66
IS 15-16
BP 1321
EP 1331
DI 10.1016/j.jastp.2004.03.019
PG 11
WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
GA 865AN
UT WOS:000224674900008
ER
PT J
AU Vassiliadis, D
Weigel, RS
Baker, DN
Kanekal, SG
Klimas, A
AF Vassiliadis, D
Weigel, RS
Baker, DN
Kanekal, SG
Klimas, A
TI Probing the solar wind-inner magnetospheric coupling: validation of
relativistic electron flux models
SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS
LA English
DT Article
DE magnetic storms; solar wind/magnetosphere interactions; radiation belts;
particle acceleration; solar cycle; forecasting; space weather
ID RADIATION BELT ELECTRONS; SEMIANNUAL VARIATION; GEOMAGNETIC-ACTIVITY;
GEOSYNCHRONOUS ORBIT; MAGNETIC CLOUD; PREDICTION; DYNAMICS
AB High fluxes of relativistic electrons in the inner magnetosphere have been associated with a range of spacecraft anomalies, and therefore the modeling of the flux is of direct relevance to the development of space weather applications. Time variations of the electron flux at a given L shell are ultimately functions of interplanetary parameters as well as of internal magnetospheric dynamics. It is important to resolve which one of the two elements is important for modeling and to what extent. To that end we compare two models of the magnetospheric relativistic electron flux at 2-6 MeV spanning the range L = 1-10 and driven by the solar wind plasma velocity, Vsw. The finite-impulse-response (FIR) model represents the coupling of the flux to the solar wind velocity. It is part of an empirical model chain currently in development at the Center for Integrated Space Weather Modeling. The autoregressive moving-average (ARMA) model also includes a representation of the internal flux dynamics. The comparison is quantified in terms of the prediction accuracy, its variation with season and solar cycle phase, and its dependence on activity level. We find that the FIR model is more accurate than the ARMA model in most radial regions of the radiation belts, including the geosynchronous orbit. The results indicate that the long memory of the FIR model to past solar wind velocity inputs is more important in representing the effective coupling than ARMA's additional internal dynamics. (C) 2004 Published by Elsevier Ltd.
C1 USRA, Rockville, MD 20850 USA.
NASA, Goddard Space Flight Ctr, Rockville, MD 20850 USA.
Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA.
Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA.
NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA.
RP USRA, Rockville, MD 20850 USA.
EM Vassi@electra.gsfc.nasa.gov
NR 30
TC 4
Z9 4
U1 0
U2 1
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 1364-6826
EI 1879-1824
J9 J ATMOS SOL-TERR PHY
JI J. Atmos. Sol.-Terr. Phys.
PD OCT-NOV
PY 2004
VL 66
IS 15-16
BP 1399
EP 1409
DI 10.1016/j.jastp.2004.03.025
PG 11
WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences
GA 865AN
UT WOS:000224674900014
ER
PT J
AU Arnaud, SB
Liang, MTC
Bassin, S
Braun, W
Dutto, D
Plesums, K
Huynh, HT
Cooper, D
Wong, N
AF Arnaud, SB
Liang, MTC
Bassin, S
Braun, W
Dutto, D
Plesums, K
Huynh, HT
Cooper, D
Wong, N
TI Ethnic differences in bending stiffness of the ulna and tibia.
SO JOURNAL OF BONE AND MINERAL RESEARCH
LA English
DT Meeting Abstract
CT 26th Annual Meeting of the
American-Society-for-Bone-and-Mineral-Research
CY OCT 01-05, 2004
CL Seattle, WA
SP Amer Soc Bone & Mineral Res
C1 NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA.
Calif State Polytech Univ Pomona, Pomona, CA 91768 USA.
Univ Calif Irvine, Dept Pediat, Irvine, CA USA.
Univ Calif Irvine, GCRC, Irvine, CA USA.
Univ Calif Irvine, Dept Cardiol, Irvine, CA USA.
NR 0
TC 0
Z9 0
U1 0
U2 1
PU AMER SOC BONE & MINERAL RES
PI WASHINGTON
PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA
SN 0884-0431
J9 J BONE MINER RES
JI J. Bone Miner. Res.
PD OCT
PY 2004
VL 19
SU 1
BP S126
EP S126
PG 1
WC Endocrinology & Metabolism
SC Endocrinology & Metabolism
GA 860FB
UT WOS:000224326800490
ER
PT J
AU Dovi, JV
van der Meulen, MCH
Damsky, CH
Kim, JB
Almeida, EAC
Globus, RK
AF Dovi, JV
van der Meulen, MCH
Damsky, CH
Kim, JB
Almeida, EAC
Globus, RK
TI In vitro functions of betal integrins in mature cells of the osteoblast
lineage.
SO JOURNAL OF BONE AND MINERAL RESEARCH
LA English
DT Meeting Abstract
CT 26th Annual Meeting of the
American-Society-for-Bone-and-Mineral-Research
CY OCT 01-05, 2004
CL Seattle, WA
SP Amer Soc Bone & Mineral Res
C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Cornell Univ, Ithaca, NY USA.
Univ Calif San Francisco, San Francisco, CA 94143 USA.
Stanford Univ, Palo Alto, CA 94304 USA.
RI van der Meulen, Marjolein/D-1549-2010
OI van der Meulen, Marjolein/0000-0001-6637-9808
NR 0
TC 0
Z9 0
U1 0
U2 0
PU AMER SOC BONE & MINERAL RES
PI WASHINGTON
PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA
SN 0884-0431
J9 J BONE MINER RES
JI J. Bone Miner. Res.
PD OCT
PY 2004
VL 19
SU 1
BP S287
EP S287
PG 1
WC Endocrinology & Metabolism
SC Endocrinology & Metabolism
GA 860FB
UT WOS:000224326801516
ER
PT J
AU Genc, KO
Maender, CC
Rice, AJ
Ochia, RS
Snedeker, JG
Cavanagh, PR
AF Genc, KO
Maender, CC
Rice, AJ
Ochia, RS
Snedeker, JG
Cavanagh, PR
TI Treadmill exercise on the International Space Station: The effects of
external loading.
SO JOURNAL OF BONE AND MINERAL RESEARCH
LA English
DT Meeting Abstract
CT 26th Annual Meeting of the
American-Society-for-Bone-and-Mineral-Research
CY OCT 01-05, 2004
CL Seattle, WA
SP Amer Soc Bone & Mineral Res
C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
Cleveland Clin Fdn, Cleveland, OH 44195 USA.
Rush Presbyterian St Lukes Med Ctr, Chicago, IL 60612 USA.
ETH, Zurich, Switzerland.
RI Snedeker, Jess/C-2105-2009
OI Snedeker, Jess/0000-0002-8115-0275
NR 0
TC 0
Z9 0
U1 0
U2 0
PU AMER SOC BONE & MINERAL RES
PI WASHINGTON
PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA
SN 0884-0431
J9 J BONE MINER RES
JI J. Bone Miner. Res.
PD OCT
PY 2004
VL 19
SU 1
BP S452
EP S452
PG 1
WC Endocrinology & Metabolism
SC Endocrinology & Metabolism
GA 860FB
UT WOS:000224326802522
ER
PT J
AU Hefferan, TE
Evans, GL
Zhang, M
Morey-Holton, E
Turner, RT
AF Hefferan, TE
Evans, GL
Zhang, M
Morey-Holton, E
Turner, RT
TI The anabolic bone response to low dose PTH is attenuated by reduced
physical activity.
SO JOURNAL OF BONE AND MINERAL RESEARCH
LA English
DT Meeting Abstract
CT 26th Annual Meeting of the
American-Society-for-Bone-and-Mineral-Research
CY OCT 01-05, 2004
CL Seattle, WA
SP Amer Soc Bone & Mineral Res
C1 Mayo Clin, Coll Med, Rochester, MN USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
NR 0
TC 0
Z9 0
U1 0
U2 0
PU AMER SOC BONE & MINERAL RES
PI WASHINGTON
PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA
SN 0884-0431
J9 J BONE MINER RES
JI J. Bone Miner. Res.
PD OCT
PY 2004
VL 19
SU 1
BP S193
EP S193
PG 1
WC Endocrinology & Metabolism
SC Endocrinology & Metabolism
GA 860FB
UT WOS:000224326801119
ER
PT J
AU Rice, AJ
Maender, CC
Genc, KO
Ochia, RS
Snedeker, JQ
Cavanagh, PR
AF Rice, AJ
Maender, CC
Genc, KO
Ochia, RS
Snedeker, JQ
Cavanagh, PR
TI Bone loss and lower extremity loading during long-duration space flight.
SO JOURNAL OF BONE AND MINERAL RESEARCH
LA English
DT Meeting Abstract
CT 26th Annual Meeting of the
American-Society-for-Bone-and-Mineral-Research
CY OCT 01-05, 2004
CL Seattle, WA
SP Amer Soc Bone & Mineral Res
C1 Cleveland Clin Fdn, Cleveland, OH 44195 USA.
NASA, Johnson Space Ctr, Houston, TX USA.
Rush Presbyterian St Lukes Med Ctr, Chicago, IL 60612 USA.
ETH, Zurich, Switzerland.
RI Snedeker, Jess/C-2105-2009
OI Snedeker, Jess/0000-0002-8115-0275
NR 0
TC 0
Z9 0
U1 1
U2 1
PU AMER SOC BONE & MINERAL RES
PI WASHINGTON
PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA
SN 0884-0431
J9 J BONE MINER RES
JI J. Bone Miner. Res.
PD OCT
PY 2004
VL 19
SU 1
BP S95
EP S95
PG 1
WC Endocrinology & Metabolism
SC Endocrinology & Metabolism
GA 860FB
UT WOS:000224326800373
ER
PT J
AU Thierry-Palme, M
Cephas, S
Sayavongsa, P
Cleek, T
Arnaud, SB
AF Thierry-Palme, M
Cephas, S
Sayavongsa, P
Cleek, T
Arnaud, SB
TI High salt intake promotes urinary loss of vitamin D metabolites by Dahl
salt-sensitive rats in a space flight model.
SO JOURNAL OF BONE AND MINERAL RESEARCH
LA English
DT Meeting Abstract
CT 26th Annual Meeting of the
American-Society-for-Bone-and-Mineral-Research
CY OCT 01-05, 2004
CL Seattle, WA
SP Amer Soc Bone & Mineral Res
C1 Morehouse Sch Med, Atlanta, GA 30310 USA.
NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA.
NR 0
TC 0
Z9 0
U1 0
U2 0
PU AMER SOC BONE & MINERAL RES
PI WASHINGTON
PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA
SN 0884-0431
J9 J BONE MINER RES
JI J. Bone Miner. Res.
PD OCT
PY 2004
VL 19
SU 1
BP S392
EP S392
PG 1
WC Endocrinology & Metabolism
SC Endocrinology & Metabolism
GA 860FB
UT WOS:000224326802274
ER
PT J
AU Vazquez-Cuervo, J
Armstrong, EM
Harris, A
AF Vazquez-Cuervo, J
Armstrong, EM
Harris, A
TI The effect of aerosols and clouds on the retrieval of infrared sea
surface temperatures
SO JOURNAL OF CLIMATE
LA English
DT Article
ID HIGH-RESOLUTION RADIOMETER; TRACK SCANNING RADIOMETER; SATELLITE
RETRIEVALS; ELIMINATION; BIAS
AB Comparisons are performed between spatially averaged sea surface temperatures (ASST2) as derived from the second Along-Track Scanning Radiometer (ATSR-2) on board the second European Remote Sensing Satellite (ERS-2) and the NOAA-NASA Advanced Very High Resolution Radiometer (AVHRR) Oceans Pathfinder dataset (MPFSST). Difference maps, MPFSST 2 ASST2, along with the application of a simple statistical regression model to aerosol and cloud data from the Total Ozone Mapping Spectrometer ( TOMS), are used to examine the impact of possible aerosol and cloud contamination. Differences varied regionally, but the largest biases were seen off western Africa. Nighttime and daytime differences off western Africa were reduced from -0.5degrees to -0.2degreesC and from -0.1degrees to 0degreesC, respectively. Significant cloud flagging, based on the model, occurred in the Indian Ocean, the equatorial Pacific, and in the vicinity of the Gulf Stream. Comparisons of the MPFSST and the ASST2 with in situ data from the 2002 version of the World Oceanic Database (WOD02) off western Africa show larger mean differences for the MPFSST. The smallest mean differences occurred for nighttime ASST2 - WOD02 with a value of 0.0degrees +/- 0.4degreesC.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, NOAA, Cooperat Inst Climate Studies, College Pk, MD 20742 USA.
RP Vazquez-Cuervo, J (reprint author), CALTECH, Jet Prop Lab, M-S 300-323,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM jv@pacific.jpl.nasa.gov
NR 21
TC 31
Z9 32
U1 1
U2 6
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0894-8755
J9 J CLIMATE
JI J. Clim.
PD OCT
PY 2004
VL 17
IS 20
BP 3921
EP 3933
DI 10.1175/1520-0442(2004)017<3921:TEOAAC>2.0.CO;2
PG 13
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 863UE
UT WOS:000224588000004
ER
PT J
AU Chou, SH
Nelkin, E
Ardizzone, J
Atlas, RM
AF Chou, SH
Nelkin, E
Ardizzone, J
Atlas, RM
TI A comparison of latent heat fluxes over global oceans for four flux
products
SO JOURNAL OF CLIMATE
LA English
DT Article
ID SEA-SURFACE TEMPERATURE; SENSOR MICROWAVE IMAGER; BULK AERODYNAMIC
ALGORITHMS; NCEP REANALYSES; WIND-SPEED; TOGA COARE; WARM POOL; DATA
SETS; PACIFIC; LAYER
AB The ocean surface latent heat flux (LHF) plays an essential role in global energy and water cycle variability. In this study, monthly LHF over global oceans during 1992-93 are compared among Goddard Satellite-Based Surface Turbulent Fluxes, version 2 (GSSTF2), Hamburg Ocean-Atmosphere Parameters and Fluxes from Satellite Data (HOAPS), NCEP-NCAR reanalysis (NCEP), and da Silva et al. (da Silva). To find the causes for discrepancies of LHF, monthly 10-m wind speed (U-10m), 10-m specific humidity (Q(10m)), and sea-air humidity difference (Q(S-)Q(10m)) are also compared during the same period. The mean differences, standard deviations of differences, and temporal correlation of these monthly variables over global oceans during 1992-93 between GSSTF2 and each of the other three datasets are analyzed. The large-scale patterns of the 2-yr-mean fields for these variables are similar among these four datasets, but significant quantitative differences are found.
The temporal correlation is higher in the northern extratropics than in the south for all variables, with the contrast being especially large for da Silva as a result of more missing ship observations in the south. The da Silva dataset has extremely low temporal correlation and large differences with GSSTF2 for all variables in the southern extratropics, indicating that da Silva hardly produces a realistic variability in these variables. The NCEP has extremely low temporal correlation (0.27) and large spatial variations of differences with GSSTF2 for Q(s) -Q(10m) in the Tropics, which causes the low correlation for LHF. Over the Tropics, the HOAPS mean LHF is significantly smaller than GSSTF2 by similar to31% (37 W m(-2)), whereas the other two datasets are comparable to GSSTF2. This is because the HOAPS has systematically smaller LHF than GSSTF2 in space, while the other two datasets have very large spatial variations of large positive and negative LHF differences with GSSTF2 to cancel and to produce smaller regional-mean differences. Based on comparison with high-quality flux observations, we conclude that the GSSTF2 latent heat flux, surface air humidity, and winds are likely to be more realistic than the other three flux datasets examined, although those of GSSTF2 are still subject to regional biases.
C1 NASA, Atmospheres Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Sci Syst & Applicat Inc, Lanham, MD USA.
Sci Applicat Int Corp, Laurel, MD USA.
RP Chou, SH (reprint author), Natl Taiwan Univ, Dept Atmospher Sci, 1,Sect 4,Roosevelt Rd, Taipei 106, Taiwan.
EM shchou@atmos1.as.ntu.edu.tw
RI Atlas, Robert/A-5963-2011
OI Atlas, Robert/0000-0002-0706-3560
NR 34
TC 33
Z9 35
U1 2
U2 4
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0894-8755
J9 J CLIMATE
JI J. Clim.
PD OCT
PY 2004
VL 17
IS 20
BP 3973
EP 3989
DI 10.1175/1520-0442(2004)017<3973:ACOLHF>2.0.CO;2
PG 17
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 863UE
UT WOS:000224588000008
ER
PT J
AU Bay, SD
Chrisman, L
Pohorille, A
Shrager, J
AF Bay, SD
Chrisman, L
Pohorille, A
Shrager, J
TI Temporal aggregation bias and inference of causal regulatory networks
SO JOURNAL OF COMPUTATIONAL BIOLOGY
LA English
DT Article
DE temporal aggregation; causal inference; spurious causation; regulatory
networks; dynamic Bayesian networks; Granger causality
ID DNA MICROARRAY ANALYSIS; GENE-EXPRESSION; ESCHERICHIA-COLI; CELL-CYCLE;
MODELS
AB Time course experiments with microarrays have begun to provide a glimpse into the dynamic behavior of gene expression. In a typical experiment, scientists use microarrays to measure the abundance of mRNA at discrete time points after the onset of a stimulus. Recently, there has been much work on using these data to infer causal regulatory networks that model how genes influence each other. However, microarray studies typically have slow sampling rates that can lead to temporal aggregation of the signal. That is, each successive sampling point represents the sum of all signal changes since the previous sample. In this paper, we show that temporal aggregation can bias algorithms for causal inference and lead them to discover spurious relations that would not be found if the signal were sampled at a much faster rate. We discuss the implications of temporal aggregation on inference, the problems it creates, and potential directions for solutions.
C1 Inst Study Learning & Expertise, Palo Alto, CA 94306 USA.
NASA, Ames Res Ctr, Ctr Computat Astrobiol & Fundamental Biol, Stanford, CA 94305 USA.
Carnegie Inst Washington, Dept Plant Biol, Stanford, CA 94305 USA.
RP Bay, SD (reprint author), Inst Study Learning & Expertise, 2164 Staunton Court, Palo Alto, CA 94306 USA.
EM sbay@apres.stanford.edu
RI Rosa, Bruce/F-6393-2010
NR 51
TC 13
Z9 13
U1 0
U2 2
PU MARY ANN LIEBERT INC
PI LARCHMONT
PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA
SN 1066-5277
J9 J COMPUT BIOL
JI J. Comput. Biol.
PD OCT
PY 2004
VL 11
IS 5
BP 971
EP 985
DI 10.1089/1066527042432297
PG 15
WC Biochemical Research Methods; Biotechnology & Applied Microbiology;
Computer Science, Interdisciplinary Applications; Mathematical &
Computational Biology; Statistics & Probability
SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology;
Computer Science; Mathematical & Computational Biology; Mathematics
GA 870WZ
UT WOS:000225090800011
PM 15700412
ER
PT J
AU Guo, J
Datta, S
Anantram, MP
Lundstrom, M
AF Guo, Jing
Datta, Supriyo
Anantram, M. P.
Lundstrom, Mark
TI Atomistic Simulation of Carbon Nanotube Field-Effect Transistors Using
Non-Equilibrium Green's Function Formalism
SO JOURNAL OF COMPUTATIONAL ELECTRONICS
LA English
DT Article
DE carbon nanotubes; transistors; quantum transport
AB Carbon Nanotube (CNT) Electronics attracts much attention for both basic and applied research. We first review a previously developed atomistic simulator for ballistic carbon nanotube transistors [1]. A recent work shows that our modeling of electrostatics, quantum transport, and contacts is sufficient to describe experiment [2]. A self-consistent atomistic simulation for a CNTFET imposes significant computational challenges. In this paper, we show how to efficiently implement the atomistic simulation by using computational techniques for computing Green's function, solving 3D Poisson equation, running parallel simulation, and improving convergence. A phenomenological model of metal/CNT contacts suitable for routine device simulation is also discussed in detail.
C1 [Guo, Jing] Univ Florida, Dept Elect & Comp Engn, Gainesville, FL 32611 USA.
[Datta, Supriyo; Lundstrom, Mark] Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA.
[Anantram, M. P.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Guo, J (reprint author), Univ Florida, Dept Elect & Comp Engn, Gainesville, FL 32611 USA.
EM 1guoj@ufl.edu
NR 11
TC 11
Z9 12
U1 0
U2 5
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 1569-8025
J9 J COMPUT ELECTRON
JI J. Comput. Electron.
PD OCT
PY 2004
VL 3
IS 3-4
BP 373
EP 377
DI 10.1007/s10825-004-7080-7
PG 5
WC Engineering, Electrical & Electronic; Physics, Applied
SC Engineering; Physics
GA V25LD
UT WOS:000208478600047
ER
PT J
AU Batdorf, NJ
Feiveson, AH
Schlegel, TT
AF Batdorf, NJ
Feiveson, AH
Schlegel, TT
TI Month-to-month and year-to-year reproducibility of high frequency QRS
ECG signals
SO JOURNAL OF ELECTROCARDIOLOGY
LA English
DT Article
DE coronary artery disease; ischemia; reduced amplitude zone; root mean
square voltage; kurtosis; CR leads
ID CORONARY-ARTERY-DISEASE; MYOCARDIAL-INFARCTION; AVERAGED
ELECTROCARDIOGRAM; HEALTHY-SUBJECTS; POTENTIALS; LEADS; ISCHEMIA;
STANDARD
AB High frequency electrocardiography analyzing the entire QRS complex in the frequency range of 150 to 250 Hz may prove useful in the detection of coronary artery disease, yet the long-term stability of these waveforms has not been fully characterized. Therefore, we prospectively investigated the reproducibility of the root mean squared voltage, kurtosis, and the presence versus absence of reduced amplitude zones in signal averaged 12-lead high frequency QRS recordings acquired in the supine position one month apart in 16 subjects and one year apart in 27 subjects. Reproducibility of root mean squared voltage and kurtosis was excellent over these time intervals in the limb leads, and acceptable in the precordial leads using both the V-1ead and CR-lead derivations. The relative error of root mean squared voltage was 12% mouth-to-mouth and 16% year-to-year in the serial recordings when averaged over all 12 leads. Reduced amplitude zones were also reproducible up to a rate of 87% and 81%, respectively, for the month-to-month and year-to-year recordings. We conclude that 12-lead high frequency QRS electrocardiograms are Sufficiently reproducible for clinical use.
C1 NASA, Lyndon B Johnson Space Ctr, Human Adapt & Countermeasures Off, Houston, TX 77058 USA.
NASA, Lyndon B Johnson Space Ctr, Natl Space Biomed Res Inst, Houston, TX 77058 USA.
RP Schlegel, TT (reprint author), NASA, Lyndon B Johnson Space Ctr, Human Adapt & Countermeasures Off, Mail Code SK3, Houston, TX 77058 USA.
EM todd.t.schlegel@nasa.gov
NR 22
TC 10
Z9 12
U1 0
U2 2
PU CHURCHILL LIVINGSTONE INC MEDICAL PUBLISHERS
PI PHILADELPHIA
PA CURTIS CENTER, INDEPENDENCE SQUARE WEST, PHILADELPHIA, PA 19106-3399 USA
SN 0022-0736
J9 J ELECTROCARDIOL
JI J. Electrocardiol.
PD OCT
PY 2004
VL 37
IS 4
BP 289
EP 296
DI 10.1016/j.jelectrocard.2004.2004.07.005
PG 8
WC Cardiac & Cardiovascular Systems
SC Cardiovascular System & Cardiology
GA 873TL
UT WOS:000225303900006
PM 15484157
ER
PT J
AU Elmustafa, AA
Ananda, AA
Elmahboub, WM
AF Elmustafa, AA
Ananda, AA
Elmahboub, WM
TI Bilinear behavior in nano and microindentation tests of fcc
polycrystalline materials
SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME
LA English
DT Article
DE indentation size effect; nanoindention; strain gradient plasticity;
geometrically necessary dislocations; bilinear behavior
ID STRAIN GRADIENT PLASTICITY; PRISMATIC DISLOCATION LOOPS;
SINGLE-CRYSTALS; STRESS-FIELD; HARDNESS; COPPER; METALS; SCALE;
DEFORMATION
AB alpha-brass and aluminum microhardness and deep nanoindentation data when fitted to the Taylor dislocation-hardening (TDH) model produced a straight-line behavior consistent with the model. Literature data, including copper silver and tungsten when also fitted to TDH model, exhibited results similar to the ones produced by the a-brass and aluminum data. The nanohardness data. obtained at shallower depths also exhibited straight-line behavior but with a shallower slope. Taken together the nano-microindentation data constituted what we term a "bilinear behavior " and we shall discuss possible mechanisms for this behavior.
C1 Princeton Univ, Princeton Inst Sci & Technol Mat, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA.
NASA, Langley Res Ctr, ConITS, Hampton, VA 23665 USA.
Hampton Univ, Sch Sci, Dept Math, Hampton, VA 23668 USA.
RP Elmustafa, AA (reprint author), Princeton Univ, Princeton Inst Sci & Technol Mat, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA.
NR 38
TC 13
Z9 13
U1 2
U2 7
PU ASME-AMER SOC MECHANICAL ENG
PI NEW YORK
PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA
SN 0094-4289
J9 J ENG MATER-T ASME
JI J. Eng. Mater. Technol.-Trans. ASME
PD OCT
PY 2004
VL 126
IS 4
BP 353
EP 359
DI 10.1115/1.1789962
PG 7
WC Engineering, Mechanical; Materials Science, Multidisciplinary
SC Engineering; Materials Science
GA 872FX
UT WOS:000225194200003
ER
PT J
AU Hinderer, J
Crossley, D
AF Hinderer, J
Crossley, D
TI Scientific achievements from the first phase (1997-2003) of the Global
Geodynamics Project using a worldwide network of superconducting
gravimeters
SO JOURNAL OF GEODYNAMICS
LA English
DT Review
ID BACKGROUND FREE OSCILLATIONS; CORE NUTATION PARAMETERS; EARTHS FREE
OSCILLATIONS; INCESSANT EXCITATION; NEW-GENERATION; GRAVITY-FIELD;
NOISE-LEVELS; TIDES; TIME; FG5
AB This paper aims to review the main scientific achievements which were obtained in the first phase (1997-2003) of the Global Geodynamics Project (GGP) consisting of a worldwide network of superconducting gravimeters (SG) of about 20 instruments. We show that the low noise levels reached by these instruments in various frequency bands allow us either to investigate new signals of very small amplitude or to better determine other signals previously seen. We first report new results in the long-period seismic band with special emphasis on the detection of the S-2(1) normal mode and the splitting of the fundamental spheroidal mode S-2(0) after the magnitude 8.4 Peru earthquake in 2001. We also discuss briefly the 'hum', which consists of a sequence of fundamental normal modes existing between 2 and 7 mHz even in the lack of any seismic excitation, and was first discovered on the Syowa (in Antarctica) instrument in 1998. We will comment on the search for the Slichter mode S-1(1) of degree 1 which is associated with a translational motion of the inner core inside the liquid core. Atmospheric effects are reviewed from the local to the global scale and the improvement due to pressure loading computations on residual gravity signals is shown. An interesting study exhibiting the gravity consequence due to sudden rainfall and vertical mass motion in the atmosphere (without ground pressure change) is presented. The precision of the SGs leads to some convincing results in the tidal domain, concerning the fluid core resonance effect (free core nutation (FCN)) on diurnal tides or various loading effects (linear, non-linear) from the oceans. In particular, SGs gravity measurements are shown to be useful validating tools for ocean tides, especially if they are small and/or confined to coastal regions. The low instrumental drift of the SGs also permits to investigate non-tidal effects in time-varying gravity, especially of annual periodicity. Hydrology has also a signature which can be seen in SG measurements as shown by several recent studies. At even lower frequency, there is the Chandler motion of 435-day period which leads to observable gravity changes at the Earth's surface. We finally report on the progress done in the last years in the problem of calibrating/validating space satellite data with SG surface gravity measurements. (C) 2004 Elsevier Ltd. All rights reserved.
C1 ULP, CNRS, UMR 7516, Inst Phys Globe Strasbourg, F-67084 Strasbourg, France.
St Louis Univ, Dept Earth & Atmospher Sci, St Louis, MO 63103 USA.
RP Hinderer, J (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
EM jacques.hinderer@eost.u-strasbg.fr
NR 109
TC 34
Z9 38
U1 1
U2 4
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0264-3707
J9 J GEODYN
JI J. Geodyn.
PD OCT-DEC
PY 2004
VL 38
IS 3-5
BP 237
EP 262
DI 10.1016/j.jog.2004.07.019
PG 26
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 881LP
UT WOS:000225869300003
ER
PT J
AU Crossley, D
Hinderer, J
Boy, JP
AF Crossley, D
Hinderer, J
Boy, JP
TI Regional gravity variations in Europe from superconducting gravimeters
SO JOURNAL OF GEODYNAMICS
LA English
DT Article
ID ENERGY BALANCES; LAND WATER; VARIABILITY; FIELD
AB Recent satellite missions (CHAMP, GRACE) are now returning data on the time variation of the gravity field with harmonic coefficients computed every 4 weeks. The promise is to achieve a sub-microgal accuracy that will define continental mass variations involving large-scale hydrology. With this in mind, we examine the time varying gravity field over central Europe using a limited number of high quality ground-based superconducting gravimeter stations within the Global Geodynamics Project (GGP). Our purpose is to see whether there are coherent signals between the individual stations and to compare the regional component with that predicted from models of continental hydrology. The results are encouraging. We have found, using empirical orthogonal eigenfunctions of the gravity data that a clear annual signal is present that is consistent in phase (low amplitudes in summer) and amplitude (1-3 microgal) with that determined from a large-scale model of land water in connection with global climate modeling. More work is required to define how the gravity field is related to large-scale soil moisture and other mass variations, and we have yet to compare our results to the latest satellite-derived data. (C) 2004 Elsevier Ltd. All rights reserved.
C1 St Louis Univ, Dept Earth & Atmospher Sci, St Louis, MO 63103 USA.
ULP, CNRS, UMR 7516, Inst Phys Globe Strasbourg, Strasbourg, France.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Crossley, D (reprint author), St Louis Univ, Dept Earth & Atmospher Sci, St Louis, MO 63103 USA.
EM crossley@eas.slu.edu
RI Boy, Jean-Paul/E-6677-2017
OI Boy, Jean-Paul/0000-0003-0259-209X
NR 38
TC 21
Z9 23
U1 1
U2 3
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0264-3707
J9 J GEODYN
JI J. Geodyn.
PD OCT-DEC
PY 2004
VL 38
IS 3-5
BP 325
EP 342
DI 10.1016/j.jog.2004.07.014
PG 18
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 881LP
UT WOS:000225869300008
ER
PT J
AU Amalvict, M
Hinderer, J
Makinen, J
Rosat, S
Rogister, Y
AF Amalvict, M
Hinderer, J
Makinen, J
Rosat, S
Rogister, Y
TI Long-term and seasonal gravity changes at the Strasbourg station and
their relation to crustal deformation and hydrology
SO JOURNAL OF GEODYNAMICS
LA English
DT Article
ID ABSOLUTE GRAVIMETERS; RHINEGRABEN; MOVEMENTS; WATER
AB The time-varying gravity is observed at the Strasbourg station with super-conducting gravimeters (SG) since 1987, with a first record from 1987 to 1996 (GWR T005) and a second one in continuity from 1996 till now (GWR C026). The long-term behaviour of the SG is constrained by regular absolute gravity (AG) measurements, which are performed in parallel since 1989, first with the JILAg-5 instrument and later on with the FG5#206. Moreover, a permanent GPS station, which belongs to the French geodetic network, has been installed at the end of 1999. We will show that the AG measurements suggest that the gravity is slowly increasing in time at a rate of about 1.6 muGal/year, and besides, exhibits a quasi-annual component of several muGal variable amplitude. We present an analysis of the GPS data obtained at the SG station in the Rhine graben as well as at another regional station in the Vosges mountains distant by about 40 km in order to constrain the gravity contribution due to the vertical displacement of the station in the earth's gravity field (geometrical part). The tectonic context of the region is described and our first results from our two data sets of limited duration suggest a small subsidence of our station in the graben; however, this fact needs further confirmation when more geodetic data will be available. We also analyze the water table changes beneath the station (local scale) and in the Alsatian Plain (regional scale) to estimate the hydrological contributions from ground water to the gravity residual signal, and we show that some similarities exist between the gravity residuals and the hydrological contributions, especially for the seasonal terms. Other missing contributions of annual period (air mass motion in the atmosphere, ocean circulation, continental hydrology) have to be considered. (C) 2004 Elsevier Ltd. All rights reserved.
C1 ULP, CNRS, UMR 7516, EOST,IPGS, Strasbourg, France.
Finnish Geodet Inst, Helsinki, Finland.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Amalvict, M (reprint author), ULP, CNRS, UMR 7516, EOST,IPGS, Strasbourg, France.
EM martine.amalvict@eost.u-strasbg.fr
RI Rosat, Severine/P-3438-2014
OI Rosat, Severine/0000-0003-4606-2170
NR 37
TC 19
Z9 19
U1 1
U2 4
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0264-3707
J9 J GEODYN
JI J. Geodyn.
PD OCT-DEC
PY 2004
VL 38
IS 3-5
BP 343
EP 353
DI 10.1016/j.jog.2004.07.010
PG 11
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 881LP
UT WOS:000225869300009
ER
PT J
AU Llubes, M
Florsch, N
Hinderer, J
Longuevergne, L
Amalvict, M
AF Llubes, M
Florsch, N
Hinderer, J
Longuevergne, L
Amalvict, M
TI Local hydrology, the Global Geodynamics Project and CHAMP/GRACE
perspective: some case studies
SO JOURNAL OF GEODYNAMICS
LA English
DT Article
ID ENERGY BALANCES; GRAVITY-FIELD; LAND WATER; EARTH; VARIABILITY;
DEFORMATION; GRACE; MODEL
AB We first quantify the influence of aquifers on gravity variations by considering local, regional and continental scales. We show that locally only the direct attraction of the underlying aquifer has to be taken into account. At continental (or global scales), the underground water masses act by direct attraction (due to the earth curvature), loading flexure and potential redistribution. We show that at the intermediate regional scale (saying a few kilometres to a few hundreds of kilometres), groundwater contributions can be neglected in practice. Afterwards, we illustrate the difficulties in tackling the local hydrological context by studying comparatively the geological and hydrogeological surroundings of three European Global Geodynamics Project (GGP) superconducting gravimeter stations (Strasbourg, Moxa, and Vienna). Finally, it appears clearly that hydrological variability and cycle characterisations constitute the up-to-date challenge while studying gravity variations in a large spectral range. That is why, gravity is used to quantify hydrological transfers, and overall when seeking for small signals from the Earth's deep interior or other environmental signals (atmosphere, oceans) where groundwater influence can be seen as a disturbance. (C) 2004 Elsevier Ltd. All rights reserved.
C1 CNRS, CNES, LEGOS, F-31401 Toulouse 9, France.
UPMC, UMR 7619, F-75252 Paris 05, France.
ULP, CNRS, UMR 7516 Sisyphe, EOST IPGS, F-67084 Strasbourg, France.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP CNRS, CNES, LEGOS, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
EM muriel.llubes@notos.cst.cnes.fr
RI Longuevergne, Laurent /F-4641-2010
OI Longuevergne, Laurent /0000-0003-3169-743X
NR 37
TC 43
Z9 43
U1 2
U2 5
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0264-3707
J9 J GEODYN
JI J. Geodyn.
PD OCT-DEC
PY 2004
VL 38
IS 3-5
BP 355
EP 374
DI 10.1016/j.jog.2004.07.015
PG 20
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 881LP
UT WOS:000225869300010
ER
PT J
AU Boy, JP
Llubes, M
Ray, R
Hinderer, J
Florsch, N
Rosat, S
Lyard, F
Letellier, T
AF Boy, JP
Llubes, M
Ray, R
Hinderer, J
Florsch, N
Rosat, S
Lyard, F
Letellier, T
TI Non-linear oceanic tides observed by superconducting gravimeters in
Europe
SO JOURNAL OF GEODYNAMICS
LA English
DT Article
ID TIDAL GRAVITY; EARTH; SHELF; MODEL; ALTIMETRY; SEA
AB We have analyzed data from nine superconducting gravimeters in Western Europe and detected the contribution of non-linear ocean tides in the quarter-diurnal and sixth-diurnal frequency bands. Despite their small amplitudes, a few nanogals (10(-11) ms(-2)), we have compared the tidal loading observations with the loading effects inferred from several non-linear ocean tide models over the North-West European continental shelf and found that they are coherent with the recent models. We also confirmed our results with tide gauge data and Topex/Poseidon altimetric data.
We have also shown that the differences between the ocean tidal models are significantly larger than the accuracy of recent superconducting gravimeters. Therefore, we suggest that gravity measurements can be used as an independent validation tool for non-linear ocean tidal models, complementary to tide gauge and bottom pressure records. (C) 2004 Published by Elsevier Ltd.
C1 NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA.
CNRS, CNES, LEGOS, F-31401 Toulouse, France.
EOST, IPGS, UMR 7516, F-67084 Strasbourg, France.
Univ Paris 06, UMR 7619 Sysiphe, Dept Geophys Appl, F-75252 Paris 05, France.
RP Boy, JP (reprint author), NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Code 926, Greenbelt, MD 20771 USA.
EM jpboy@eost.u-strasbg.fr
RI Ray, Richard/D-1034-2012; Rosat, Severine/P-3438-2014; Boy,
Jean-Paul/E-6677-2017
OI Rosat, Severine/0000-0003-4606-2170; Boy, Jean-Paul/0000-0003-0259-209X
NR 28
TC 14
Z9 15
U1 1
U2 7
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0264-3707
J9 J GEODYN
JI J. Geodyn.
PD OCT-DEC
PY 2004
VL 38
IS 3-5
BP 391
EP 405
DI 10.1016/j.jog.2004.07.017
PG 15
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 881LP
UT WOS:000225869300012
ER
PT J
AU Rosat, S
Hinderer, J
Crossley, D
Boy, JP
AF Rosat, S
Hinderer, J
Crossley, D
Boy, JP
TI Performance of superconducting gravimeters from long-period seismology
to tides
SO JOURNAL OF GEODYNAMICS
LA English
DT Article
ID EARTHS INNER CORE; FREE OSCILLATIONS; NOISE-LEVELS; NORMAL-MODES;
SEARCH; TRIPLET
AB The first phase (1997-2003) of the Global Geodynamics Project (GGP) has now been completed. Data from superconducting gravimeters (SGs) within GGP have shown great capabilities in a wide spectrum of geophysical applications from the tidal studies to the long-period seismology. Here, we compare the noise levels of the different contributing stations over the whole spectrum. We use three different processing procedures to evaluate the combined instrument-plus-site noise in the long-period seismic band (200-600 s), in the sub-seismic band (1-6 h) and in the tidal bands (12-24 h). The analysis in the seismic band has demonstrated that SGs are particularly well suited for the studies of the long-period normal modes and thus are complementary to long-period seismometers. In the subseismic band, the power spectral densities, computed over a period of 15 continuous days for every GGP station, cross the New Low Noise Model of Peterson from T= 16 min to T= 4.6 h. SG data are therefore appropriate for studying long-period seismic and sub-seismic modes. In the tidal bands, the noise comparison is realised by a least-squares fit to tides, local air pressure and instrumental drift, leading to gravity residuals where we estimate a standard deviation and average noise levels in different tidal frequency bands. Tidal gravity observations using SGs have also shown to be an independent validation tool of ocean tidal models, and they are therefore complementary to tide gauge and altimetric data sets. Knowledge of the noise levels at each station is important in a number of studies that combine the data to determine global Earth parameters. We illustrate it with the stacking of the data in the search for the gravity variations associated with the sub-seismic translational motions of the inner core, the so-called Slichter triplet. (C) 2004 Elsevier Ltd. All rights reserved.
C1 ULP, CNRS, UMR 7516, IPGS,EOST, F-67084 Strasbourg, France.
St Louis Univ, Dept Earth & Atmospher Sci, St Louis, MO 63103 USA.
NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA.
RP Rosat, S (reprint author), ULP, CNRS, UMR 7516, IPGS,EOST, 5 Rue Descartes, F-67084 Strasbourg, France.
EM srosat@eost.u-strasbg.fr
RI Rosat, Severine/P-3438-2014; Boy, Jean-Paul/E-6677-2017
OI Rosat, Severine/0000-0003-4606-2170; Boy, Jean-Paul/0000-0003-0259-209X
NR 37
TC 40
Z9 43
U1 2
U2 13
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0264-3707
J9 J GEODYN
JI J. Geodyn.
PD OCT-DEC
PY 2004
VL 38
IS 3-5
BP 461
EP 476
DI 10.1016/j.jog.2004.07.005
PG 16
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 881LP
UT WOS:000225869300017
ER
PT J
AU Yang, FL
Kumar, A
Lau, KM
AF Yang, FL
Kumar, A
Lau, KM
TI Potential predictability of US summer climate with "perfect'' soil
moisture
SO JOURNAL OF HYDROMETEOROLOGY
LA English
DT Article
ID SEA-SURFACE TEMPERATURES; UNITED-STATES; PRECIPITATION VARIABILITY;
SEASONAL PREDICTION; FORECAST SYSTEM; NORTH-AMERICA; MODEL; PACIFIC;
LAND; TELECONNECTIONS
AB The potential predictability of surface-air temperature and precipitation over the United States was assessed for a GCM forced by observed sea surface temperatures and an estimate of observed soil-moisture content. The latter was obtained by substituting the GCM-simulated precipitation, which is used to drive the GCM's land surface component, with observed pentad-mean precipitation at each time step of the model's integration. With this substitution, the simulated soil moisture correlates well with an independent estimate of observed soil moisture in all seasons over the entire U. S. continent. Significant enhancements for the predictability of surface-air temperature and precipitation were found in boreal late spring and summer over the U. S. continent. Anomalous pattern correlations of precipitation and surface-air temperature over the U. S. continent in the June - August season averaged for the 1979 - 2000 period increased from 0.01 and 0.06 for the GCM simulations without precipitation substitution to 0.23 and 0.31, respectively, for the simulations with precipitation substitution. The results provide an estimate for the limits of potential predictability if soil-moisture variability is to be perfectly predicted. However, this estimate may be model dependent and needs to be substantiated by other modeling groups.
C1 NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, GEST UMBC,Lab Atmospheres, Greenbelt, MD 20771 USA.
Natl Ctr Environm Predict, Climate Predict Ctr, Washington, DC USA.
NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
RP Yang, FL (reprint author), NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, GEST UMBC,Lab Atmospheres, Code 913, Greenbelt, MD 20771 USA.
EM fyang@climate.gsfc.nasa.gov
RI Yang, Fanglin/A-1948-2013; Lau, William /E-1510-2012
OI Lau, William /0000-0002-3587-3691
NR 36
TC 17
Z9 19
U1 1
U2 4
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 1525-755X
J9 J HYDROMETEOROL
JI J. Hydrometeorol.
PD OCT
PY 2004
VL 5
IS 5
BP 883
EP 895
DI 10.1175/1525-7541(2004)005<0883:PPOUSC>2.0.CO;2
PG 13
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 867MT
UT WOS:000224847400013
ER
PT J
AU Anisimov, MA
Zhong, F
Barmatz, M
AF Anisimov, MA
Zhong, F
Barmatz, M
TI Resolving the Yang-Yang dilemma in He-3 near the critical point
SO JOURNAL OF LOW TEMPERATURE PHYSICS
LA English
DT Article
DE Yang-Yang relation; critical phenomena; He-3; thermodynamics
ID VAPOR CRITICAL-POINT; ISOCHORIC HEAT-CAPACITY; CRITICAL REGION;
RENORMALIZATION-GROUP; HE-3-HE-4 MIXTURE; CARBON-DIOXIDE; LIQUID;
FLUIDS; EQUATION; STATE
AB A challenging problem is to experimentally resolve the Yang-Yang dilemma for fluids-whether the critical singularity of the isochoric heat capacity is shared between the second temperature derivatives of pressure and chemical potentials. In the lattice-gas model, which serves as a well-established guidance to study fluid criticality, the divergence of the second derivative of pressure is solely responsible for the heat capacity anomaly. If it is proven that the heat capacity singularity is shared between the pressure and chemical potential derivatives, a revision of the conventional scaling theory for fluids based on the analogy between fluids and lattice-gas model will be required. Thus far, experiments on real fluids have been inconclusive, in particular, because of possible impurity effects and the intrinsic vapor-liquid asymmetry. A study of the He-3 isotope gives a unique opportunity to resolve the Yang-Yang dilemma. In He-3 all other impurities except He-4 are frozen out. The almost perfect purity of the available He-3 samples ( typically less than 1 ppm of He-4 in He-3) enables the elimination or quantitative study of impurity effects. Also the well-known symmetry of the He-3 coexistence curve implies an absence of confluent singularities caused by liquid-gas asymmetry. In this paper we reanalyze early experimental data of near-critical 3He and show that they are internally not completely consistent. While the second derivative of chemical potential obtained from the density dependence of the two-phase isochoric heat capacity does not show a noticeable anomaly, the analysis of the same property obtained by combining the PVT and heat capacity implies the existence of the Yang-Yang anomaly. An unambiguous test of the Yang-Yang dilemma will require more accurate heat-capacity measurements closer to the critical point. To thoroughly distinguish between these alternatives one may ultimately require a microgravity experiment that will allow measurements very close to the critical point.
C1 Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA.
Univ Maryland, Dept Chem Engn, College Pk, MD 20742 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Anisimov, MA (reprint author), Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA.
EM martin.b.barmatz@jpl.nasa.gov
NR 40
TC 10
Z9 10
U1 0
U2 0
PU KLUWER ACADEMIC/PLENUM PUBL
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0022-2291
J9 J LOW TEMP PHYS
JI J. Low Temp. Phys.
PD OCT
PY 2004
VL 137
IS 1-2
BP 69
EP 88
DI 10.1023/B:JOLT.0000044235.12902.f3
PG 20
WC Physics, Applied; Physics, Condensed Matter
SC Physics
GA 861AZ
UT WOS:000224389800004
ER
PT J
AU Gasch, M
Ellerby, D
Irby, E
Beckman, S
Gusman, M
Johnson, S
AF Gasch, M
Ellerby, D
Irby, E
Beckman, S
Gusman, M
Johnson, S
TI Processing, properties and arc jet oxidation of hafnium diboride/silicon
carbide ultra high temperature ceramics
SO JOURNAL OF MATERIALS SCIENCE
LA English
DT Article; Proceedings Paper
CT Workshop on Ultra-High Temperature Ceramic Materials
CY NOV 05-07, 2003
CL Wintergreen, VA
SP AFOSR
ID ZIRCONIUM DIBORIDE; COMPOSITES
AB The processing and properties of HfB2-20 vol%SiC ultra high temperature ceramics were examined. Dense billets were fabricated by hot-pressing raw powders in a graphite element furnace for 1 h at 2200degreesC. Specimens were then tested for hardness, mechanical strength, thermal properties and oxidation resistance in a simulated re-entry environment. Thermal conductivity of the current materials was found to be less than previous work had determined while the strength was greater. Oxidation testing of two flat-face models was conducted, at two conditions, for two 10-min durations each. It was concluded that passive oxidation of SiC plays a role in determining the steady-state surface temperatures below 1700degreesC. Above 1700degreesC, temperatures are controlled by the properties of a thick HfO2 layer and active oxidation of the SiC phase. (C) 2004 Kluwer Academic Publishers.
C1 ELORET Corp, Sunnyvale, CA 94087 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Gasch, M (reprint author), ELORET Corp, 690 W Fremont Ave, Sunnyvale, CA 94087 USA.
EM Sylvia.M.Johnson@nasa.gov
NR 15
TC 172
Z9 187
U1 4
U2 49
PU KLUWER ACADEMIC PUBL
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0022-2461
J9 J MATER SCI
JI J. Mater. Sci.
PD OCT 1
PY 2004
VL 39
IS 19
BP 5925
EP 5937
DI 10.1023/B:JMSC.0000041689.90456.af
PG 13
WC Materials Science, Multidisciplinary
SC Materials Science
GA 868DW
UT WOS:000224895300005
ER
PT J
AU Marschall, J
Erlich, DC
Manning, H
Duppler, W
Ellerby, D
Gasch, M
AF Marschall, J
Erlich, DC
Manning, H
Duppler, W
Ellerby, D
Gasch, M
TI Microhardness and high-velocity impact resistance of HfB2/SiC and
ZrB2/SiC composites
SO JOURNAL OF MATERIALS SCIENCE
LA English
DT Article; Proceedings Paper
CT Workshop on Ultra-High Temperature Ceramic Materials
CY NOV 05-07, 2003
CL Wintergreen, VA
SP AFOSR
ID HIGH-TEMPERATURE HARDNESS; STRENGTH DEGRADATION; INDENTATION FRACTURE;
BRITTLE SOLIDS; SURFACES; SPHERES
AB The results of Vickers microhardness and high-velocity impact tests on monolithic ZrB2/SiC and HfB2/SiC ultra-high temperature ceramic (UHTC) composites are presented. The UHTC materials exhibit fracture behavior typical of ceramics under indentation and impact loading. The materials are relatively hard with microhardness values of about 15 to 20 GPa. Cracks were observed to extend from the corners of indentations. Impacts of stainless steel and tungsten carbide spheres, with diameters in the 500 to 800 micron range and velocities of 200 to 300 m/s, produced minimal plastic deformation but significant radial and ring cracking at the impact sites. Impacts of micron-scale iron particles traveling at 1 to 3 km/s produced essentially no surface damage. (C) 2004 Kluwer Academic Publishers.
C1 SRI Int, Mol Phys Lab, Menlo Pk, CA 94025 USA.
Concordia Coll, Dept Phys, Moorhead, MN 56562 USA.
NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA.
RP Marschall, J (reprint author), SRI Int, Mol Phys Lab, Menlo Pk, CA 94025 USA.
EM jochen.marschall@sri.com
NR 31
TC 29
Z9 29
U1 2
U2 11
PU KLUWER ACADEMIC PUBL
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0022-2461
J9 J MATER SCI
JI J. Mater. Sci.
PD OCT 1
PY 2004
VL 39
IS 19
BP 5959
EP 5968
DI 10.1023/B:JMSC.0000041692.72915.e8
PG 10
WC Materials Science, Multidisciplinary
SC Materials Science
GA 868DW
UT WOS:000224895300008
ER
PT J
AU Opila, E
Levine, S
Lorincz, J
AF Opila, E
Levine, S
Lorincz, J
TI Oxidation of ZrB(2)- and HfB(2)-based ultra-high temperature ceramics:
Effect of Ta additions
SO JOURNAL OF MATERIALS SCIENCE
LA English
DT Article; Proceedings Paper
CT Workshop on Ultra-High Temperature Ceramic Materials
CY NOV 05-07, 2003
CL Wintergreen, VA
SP AFOSR
ID SYSTEM
AB Several compositions of ZrB(2)- and HfB(2)-based Ultra-High Temperature Ceramics (UHTC) were oxidized in stagnant air at 1627degreesC in ten minute cycles for times up to 100 min. These compositions include: ZrB(2)-20 vol% SiC, HfB(2)-20 vol% SiC, ZrB(2)-20 vol% SiC-20 vol% TaSi(2), ZrB(2)-33 vol% SiC, HfB(2)-20 vol% SiC-20 vol% TaSi(2), and ZrB(2)-20 vol% SiC-20 vol% TaC. The weight change due to oxidation was recorded. The ZrB2-20 vol% SiC-20 vol% TaSi2 composition was also oxidized in stagnant air at 1927degreesC and in an arc jet atmosphere. Samples were analyzed after oxidation by X-ray diffraction, field emission scanning electron microscopy, and energy dispersive spectroscopy to determine the reaction products and to observe the microstructure. The ZrB(2)-20 vol% SiC-20 vol% TaSi(2) showed the lowest oxidation rate at 1627degreesC, but performed poorly under the more extreme tests due to liquid phase formation. Effects of Ta-additions on the oxidation of the diboride-based UHTC are discussed. (C) 2004 Kluwer Academic Publishers.
C1 NASA, Glenn Res Ctr, Brookpark, OH 44135 USA.
Ohio Univ, Athens, OH 45701 USA.
RP Opila, E (reprint author), NASA, Glenn Res Ctr, Brookpark, OH 44135 USA.
EM Elizabeth.J.Opila@grc.nasa.gov
NR 17
TC 135
Z9 149
U1 4
U2 48
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0022-2461
J9 J MATER SCI
JI J. Mater. Sci.
PD OCT 1
PY 2004
VL 39
IS 19
BP 5969
EP 5977
DI 10.1023/B:JMSC.0000041693.32531.d1
PG 9
WC Materials Science, Multidisciplinary
SC Materials Science
GA 868DW
UT WOS:000224895300009
ER
PT J
AU Sayir, A
Lowery, FS
AF Sayir, A
Lowery, FS
TI Combustion-resistance of silicon-based ceramics and composites at very
high oxygen pressures
SO JOURNAL OF MATERIALS SCIENCE
LA English
DT Article; Proceedings Paper
CT Workshop on Ultra-High Temperature Ceramic Materials
CY NOV 05-07, 2003
CL Wintergreen, VA
SP AFOSR
ID IGNITION
AB The resistance of ceramic matrix composites to combust at high oxygen pressures is expected to provide information in developing oxygen-rich propulsion systems. In contrast to metals, silicon based ceramics, SiC, Si3N4 and SiC-composites, have prevalently covalent bonding characteristics and their promoted combustion characteristics were different. These materials dissociate at very high temperatures rather than going through discrete solid-liquid phase transformation (melting). The silicon based ceramics and composites burn heterogeneously at very high oxygen pressures and the critical threshold pressure at which no test specimen sustains combustion correlated with composition, the nature of the bonding and the solubility of oxygen. (C) 2004 Kluwer Academic Publishers.
C1 Case Western Reserve Univ, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
RP Sayir, A (reprint author), Case Western Reserve Univ, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
EM Ali.Sayir@grc.nasa.gov
NR 14
TC 0
Z9 0
U1 0
U2 2
PU KLUWER ACADEMIC PUBL
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0022-2461
J9 J MATER SCI
JI J. Mater. Sci.
PD OCT 1
PY 2004
VL 39
IS 19
BP 5979
EP 5985
DI 10.1023/B:JMSC.0000041694.32736.b6
PG 7
WC Materials Science, Multidisciplinary
SC Materials Science
GA 868DW
UT WOS:000224895300010
ER
PT J
AU Deng, H
Dickey, EC
Paderno, Y
Paderno, V
Filippov, V
Sayir, A
AF Deng, H
Dickey, EC
Paderno, Y
Paderno, V
Filippov, V
Sayir, A
TI Crystallographic characterization and indentation mechanical properties
of LaB(6)-ZrB(2) directionally solidified eutectics
SO JOURNAL OF MATERIALS SCIENCE
LA English
DT Article; Proceedings Paper
CT Workshop on Ultra-High Temperature Ceramic Materials
CY NOV 05-07, 2003
CL Wintergreen, VA
SP AFOSR
ID F-TRANSITION METALS; CRYSTAL-CHEMISTRY; BORIDES; ALLOYS; COMPOSITE
AB LaB(6)-ZrB(2) eutectics were directionally solidified by a zone melting process. The microstructure and crystallography were characterized by X-ray diffraction, optical microscopy and transmission electron microscopy. The anisotropies of hardness and indentation fracture toughness were assessed by making measurements along different crystallographic directions on both transverse and longitudinal sections. While the hardness did not vary appreciably between the two orientations, the fracture toughness was observed to be highly anisotropic. Toughening behavior was observed on longitudinal sections with crack deflection and bridging mechanisms apparent. Cracks were difficult to initiate on transverse sections along directions perpendicular to the growth direction, but for 20 N loads an indentation fracture toughness of 11 MParootm could be measured. (C) 2004 Kluwer Academic Publishers.
C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA.
Penn State Univ, Inst Mat Res, University Pk, PA 16802 USA.
Ukrainian Acad Sci, Inst Problems Mat Sci, UA-252142 Kiev, Ukraine.
NASA, Lewis Res Ctr, Cleveland, OH 44135 USA.
RP Deng, H (reprint author), Penn State Univ, Dept Mat Sci & Engn, 248 MRL, University Pk, PA 16802 USA.
EM ecd10@psu.edu
RI Dickey, Elizabeth/A-3368-2011
OI Dickey, Elizabeth/0000-0003-4005-7872
NR 19
TC 21
Z9 23
U1 0
U2 6
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0022-2461
J9 J MATER SCI
JI J. Mater. Sci.
PD OCT 1
PY 2004
VL 39
IS 19
BP 5987
EP 5994
DI 10.1023/B:JMSC.0000041695.40772.56
PG 8
WC Materials Science, Multidisciplinary
SC Materials Science
GA 868DW
UT WOS:000224895300011
ER
PT J
AU Sayir, A
AF Sayir, A
TI Carbon fiber reinforced hafnium carbide composite
SO JOURNAL OF MATERIALS SCIENCE
LA English
DT Article; Proceedings Paper
CT Workshop on Ultra-High Temperature Ceramic Materials
CY NOV 05-07, 2003
CL Wintergreen, VA
SP AFOSR
ID HIGH-TEMPERATURE OXIDATION; ZIRCONIUM; RANGE
AB Hafnium carbide is proposed as a structural material for aerospace applications at ultra high temperatures. The chemical vapor deposition technique was used as a method to produce monolithic hafnium carbide (HfC) and tantalum carbide (TaC). The microstructure of HfC and TaC were studied using analytical techniques. The addition of tantalum carbide (TaC) in the HfC matrix was studied to improve the microstructure. The microstructure of HfC, TaC and co-deposited hafnium carbide-tantalum carbide (HfC/TaC) were comparable and consisted of large columnar grains. Two major problems associated with HfC, TaC, and HfC/TaC as a monolithic are lack of damage tolerance (toughness) and insufficient strength at very high temperatures. A carbon fiber reinforced HfC matrix composite has been developed to promote graceful failure using a pyrolytic graphite interface between the reinforcement and the matrix. The advantages of using carbon fiber reinforcement with a pyrolytic graphite interface are reflected in superior strain capability reaching up to 2%. The tensile strength of the composite was 26 MPa and needs further improvement. Heat treatment of the composite showed that HfC did not undergo any phase transformations and that the phases comprising composite were are thermochemically compatible. (C) 2004 Kluwer Academic Publishers.
C1 Case Western Reserve Univ, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Sayir, A (reprint author), Case Western Reserve Univ, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
EM Ali.Sayir@grc.nasa.gov
NR 34
TC 61
Z9 80
U1 3
U2 35
PU KLUWER ACADEMIC PUBL
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0022-2461
J9 J MATER SCI
JI J. Mater. Sci.
PD OCT 1
PY 2004
VL 39
IS 19
BP 5995
EP 6003
DI 10.1023/B:JMSC.0000041696.64055.8c
PG 9
WC Materials Science, Multidisciplinary
SC Materials Science
GA 868DW
UT WOS:000224895300012
ER
PT J
AU Yang, EH
Lee, C
Mueller, J
George, T
AF Yang, EH
Lee, C
Mueller, J
George, T
TI Leak-tight piezoelectric microvalve for high-pressure gas
micropropulsion
SO JOURNAL OF MICROELECTROMECHANICAL SYSTEMS
LA English
DT Article
DE high pressure; micropropulsion; microvalve; piezoelectric
AB This paper describes the results of our development of a leak-tight piezoelectric microvalve, operating at extremely high upstream pressures for microspacecraft applications. The device is a normally closed microvalve assembled and fabricated primarily from micromachined silicon wafers. The microvalve consists of a custom-designed piezoelectric stack actuator bonded onto silicon valve components (such as the seat, boss, and tether) with the entire assembly contained within a stainless steel housing. The valve seat configurations include narrow-edge seating rings and tensile-stressed silicon tethers that enable the desired, normally closed, leak-tight operation. Leak testing of the microvalve was conducted using a helium leak detector and showed leak rates of 5 x 10(-3) sccm at 800 psi (5.516 MPa). Dynamic microvalve operation (switching rates of up to 1 kHz) was successfully demonstrated for inlet pressures in the range of 0 similar to 1000 psi. The measured static flow rate for the microvalve under an applied potential of 10 V was 52 seem at an inlet pressure of 300 psi. The measured power consumption, in the fully open state, was 3 mW at an applied potential of 30 V. The measured dynamic power consumption was 180 mW for 100 Hz continuous operation at 100 psi.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Em-Hyeok.Yang@jpl.nasa.gov
OI Yang, Eui-Hyeok/0000-0003-4893-1691
NR 17
TC 38
Z9 40
U1 2
U2 9
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 1057-7157
EI 1941-0158
J9 J MICROELECTROMECH S
JI J. Microelectromech. Syst.
PD OCT
PY 2004
VL 13
IS 5
BP 799
EP 807
DI 10.1107/JMEMS.2004.83567
PG 9
WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology;
Instruments & Instrumentation; Physics, Applied
SC Engineering; Science & Technology - Other Topics; Instruments &
Instrumentation; Physics
GA 861JP
UT WOS:000224413100010
ER
PT J
AU Lewis, H
Hwang, W
Manzo, M
AF Lewis, H
Hwang, W
Manzo, M
TI Historical performance of nickel/cadmium and nickel/metal hydride
geosynchronous-orbit packs and determination of voltage/temperature
levels for advanced nickel/cadmium designs
SO JOURNAL OF POWER SOURCES
LA English
DT Article; Proceedings Paper
CT 23rd International Power Sources Symposium
CY SEP 22-24, 2003
CL Amsterdam, NETHERLANDS
DE applications/earth satellites; nickel/cadmium batteries; nickel/metal
hydride; batteries
AB This paper will review the performances of nickel/cadmium and nickel/hydrogen Geocentric Earth Orbital (GEO) satellite battery packs which have been evaluated at NAVSEA Crane for the Air Force and NASA-Glenn. The nickel/cadmium data will deal, in part, with the attempts to find space-qualified substitutes for the disappearance of Pellon 2505 as a separation material. The nickel/hydrogen data will illustrate the development of this chemistry as a substitute for nickel/cadmium batteries. (C) 2004 Elsevier B.V. All rights reserved.
C1 NAVSEA Crane, Crane, IN 47522 USA.
Aerosp Corp, Energy Technol Dept, Los Angeles, CA 90009 USA.
NASA, Lewis Res Ctr, Cleveland, OH 44135 USA.
RP Lewis, H (reprint author), NAVSEA Crane, 300 Highway 361,Code 609,B2949, Crane, IN 47522 USA.
EM lewis_h@crane.navy.mil
NR 1
TC 1
Z9 3
U1 0
U2 4
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0378-7753
J9 J POWER SOURCES
JI J. Power Sources
PD OCT 1
PY 2004
VL 136
IS 2
SI SI
BP 307
EP 316
DI 10.1016/j.jpowsour.2004.03.041
PG 10
WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials
Science, Multidisciplinary
SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science
GA 860RR
UT WOS:000224361200020
ER
PT J
AU Sukumar, V
Alahmad, M
Buck, K
Hess, H
Li, H
Cox, D
Zghoul, FN
Jackson, J
Terry, S
Blalock, B
Mojarradi, MM
West, WC
Whitacre, JF
AF Sukumar, V
Alahmad, M
Buck, K
Hess, H
Li, H
Cox, D
Zghoul, FN
Jackson, J
Terry, S
Blalock, B
Mojarradi, MM
West, WC
Whitacre, JF
TI Switch array system for thin film lithium microbatteries
SO JOURNAL OF POWER SOURCES
LA English
DT Article; Proceedings Paper
CT 23rd International Power Sources Symposium
CY SEP 22-24, 2003
CL Amsterdam, NETHERLANDS
DE LDMOSFET; micropower; microbattery; SOI
AB Integrated microbatteries are currently being developed to provide reliable low-noise voltage sources for system-on-a-chip applications by Jet Propulsion Laboratory (JPL). These microbatteries help provide localized current capacities or embedded power supplies at the chip level for space exploration. This paper presents a design approach for charging and discharging microbatteries. Maximum flexibility in terms of voltages and currents are also obtained through the use of a switching matrix. The microbatteries used for the design are rated at 50 nAh capacity and are solid-state lithium electrolyte based. The designs are built using Microwave Silicon-on-Insulator process. (C) 2004 Elsevier B.V. All rights reserved.
C1 Univ Idaho, Microelect Res & Commun Inst, Moscow, ID 83843 USA.
Univ Tennessee, Integrated Circuits & Syst Lab, Knoxville, TN USA.
CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA.
RP Sukumar, V (reprint author), Univ Idaho, Microelect Res & Commun Inst, Moscow, ID 83843 USA.
EM vinesh@mrc.uidaho.edu
NR 8
TC 10
Z9 10
U1 0
U2 1
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0378-7753
J9 J POWER SOURCES
JI J. Power Sources
PD OCT 1
PY 2004
VL 136
IS 2
SI SI
BP 401
EP 407
DI 10.1016/j.jpowsour.2004.03.033
PG 7
WC Chemistry, Physical; Electrochemistry; Energy & Fuels; Materials
Science, Multidisciplinary
SC Chemistry; Electrochemistry; Energy & Fuels; Materials Science
GA 860RR
UT WOS:000224361200033
ER
PT J
AU Cardema, JC
Wang, PKC
Rodriguez, G
AF Cardema, JC
Wang, PKC
Rodriguez, G
TI Optimal path planning of mobile robots for sample collection
SO JOURNAL OF ROBOTIC SYSTEMS
LA English
DT Article
ID VISIBILITY
AB In this paper, the problem of path planning for sample collection using single or multiple mobile robots such as Mars rovers is formulated as a mathematical optimization problem involving a performance metric based on the scientific values of the collected rock and soil samples. The posed optimization problem is NP-hard and more complex than the well-known Traveling Salesman Problem. Algorithms are proposed for obtaining near-optimal solutions for both single and multiple robots. Their application is illustrated using real Mars surface data. The dependence of the optimal performance on the number of mobile robots is studied numerically. (C) 2004 Wiley Periodicals, Inc.
C1 Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Wang, PKC (reprint author), Univ Calif Los Angeles, Dept Elect Engn, Los Angeles, CA 90095 USA.
EM pkcwang@ee.ucla.edu
NR 12
TC 4
Z9 4
U1 0
U2 0
PU JOHN WILEY & SONS INC
PI HOBOKEN
PA 111 RIVER ST, HOBOKEN, NJ 07030 USA
SN 0741-2223
J9 J ROBOTIC SYST
JI J. Robot. Syst.
PD OCT
PY 2004
VL 21
IS 10
BP 559
EP 580
DI 10.1002/rob.20036
PG 22
WC Robotics
SC Robotics
GA 853OS
UT WOS:000223837500005
ER
PT J
AU Choi, SR
Bansal, NP
AF Choi, SR
Bansal, NP
TI Shear strength as a function of test rate for SiCf/BSAS ceramic matrix
composite at elevated temperature
SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY
LA English
DT Article
ID CRACK-GROWTH; INPLANE
AB Both interlaminar and in-plane shear strengths of a unidirectional Hi-Nicalon(TM)-fiber-reinforced barium strontium aluminosilicate (SiCf/BSAS) composite were determined at 1100degreesC in air as a function of test rate using double-notch shear test specimens. The composite exhibited a significant effect of test rate on shear strength, regardless of orientation. The shear strength degraded by about 50% as the test rate decreased from 3.3 x 10(-1) to 3.3 x 10(-5) mm/s. The rate dependency of shear strength was similar to that observed for ultimate tensile strength at 1100degreesC for the two-dimensional (2-D) SiCf/BSAS composite, in which tensile strength decreased by about 60% when the test rate varied from 5 to 0.005 MPa/s. A phenomenological, power-law slow crack growth model is proposed and formulated to account for the rate dependency of shear strength of the composite. The proposed model has been validated with additional results of both constant stress-rate and constant stress testing in shear at 1100degreesC using a 2-D Nicalon-fiber-reinforced crossply magnesium aluminosilicate (SiCf/MAS-5) ceramic matrix composite.
C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Choi, SR (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
EM sung.r.choi@grc.nasa.gov
NR 22
TC 19
Z9 20
U1 0
U2 8
PU AMER CERAMIC SOC
PI WESTERVILLE
PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43086-6136 USA
SN 0002-7820
J9 J AM CERAM SOC
JI J. Am. Ceram. Soc.
PD OCT
PY 2004
VL 87
IS 10
BP 1912
EP 1918
PG 7
WC Materials Science, Ceramics
SC Materials Science
GA 869TW
UT WOS:000225008200016
ER
PT J
AU McAlister, KW
AF McAlister, KW
TI Rotor wake development during the first revolution
SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY
LA English
DT Article; Proceedings Paper
CT 59th Annual Forum of the American-Helicopter-Society
CY MAY 06, 2003
CL Phoenix, AZ
SP Amer Helicopter Soc
ID TRAILING VORTICES; HOVERING ROTOR; VORTEX; VELOCIMETRY; MODEL; BLADE;
FLOW
AB The wake behind a two-bladed model rotor in a shallow climb was measured using particle image velocimetry. The distribution of vorticity was distinguished from the slightly elliptical swirl pattern. Peculiar dynamics within the "void" region were found to accompany a shift in the peak vorticity away from the center as the vortex aged. The swirl and axial velocities (that reached 44 and 12 percent of the rotor-tip speed, respectively) were found to be asymmetric relative to the vortex center. In particular, the axial flow was composed of two concentrated zones moving in opposite directions. The radial distributions of swirl velocity and vorticity exhibit self-similar behaviors, especially within the core. The diameter of the vortex core was initially about 10 percent of the rotor-blade chord, but more than doubled its size after one revolution of the rotor. According to vortex models that approximate the measured data, the core-radius circulation was about 79 percent of the large-radius circulation, and the large-radius circulation was about 67 percent of the maximum bound circulation on the rotor blade. On average, about 53 percent of the maximum bound circulation resides within the vortex core during the first revolution of the rotor.
C1 NASA, Rotorcraft Div, Aeroflightdynam Directorate,AMRDEC, USA Aviat & Missile Command,Ames Res Ctr, Moffett Field, CA 94035 USA.
RP McAlister, KW (reprint author), NASA, Rotorcraft Div, Aeroflightdynam Directorate,AMRDEC, USA Aviat & Missile Command,Ames Res Ctr, Moffett Field, CA 94035 USA.
NR 30
TC 14
Z9 14
U1 0
U2 0
PU AMER HELICOPTER SOC INC
PI ALEXANDRIA
PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA
SN 0002-8711
J9 J AM HELICOPTER SOC
JI J. Am. Helicopter Soc.
PD OCT
PY 2004
VL 49
IS 4
BP 371
EP 390
PG 20
WC Engineering, Aerospace
SC Engineering
GA 866JX
UT WOS:000224770900001
ER
PT J
AU Shinoda, PM
Yeo, H
Norman, TR
AF Shinoda, PM
Yeo, H
Norman, TR
TI Rotor performance of a UH-60 rotor system in the NASA Ames 80-by
120-Foot Wind Tunnel
SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY
LA English
DT Article; Proceedings Paper
CT 58th Annual Forum of the American-Helicopter-Society
CY JUN 11-13, 2002
CL MONTREAL, CANADA
SP Amer Helicopter Soc
AB A full-scale four-bladed UH-60 rotor system was tested in the NASA Ames 80- by 120-Foot Wind Tunnel. A quality data set at low forward speed, 0 to 80 knots, has been obtained to support future rotor developments and analysis improvements. To evaluate the NASA Ames 80- by 120-Foot Wind Tunnel as a hover testing facility, rotor performance data were compared with predictions, UH-60 aircraft flight test data, and UH-60 model-scale data from other test facilities. The results indicate that valid hover data for this size rotor can be obtained from this facility at low to medium thrust conditions. Comparisons with flight test and model-scale data demonstrate the variability between existing data sets. Predictions show good agreement with full-scale data. To evaluate the analytical modeling in the 0 to 80 knot speed range, forward flight rotor performance data were acquired and compared with predictions. Comparisons were also made with existing model-scale and flight test data. Power calculations show fair to good agreement with full-scale wind tunnel data at advance ratios between 0.10 to 0.19 and poor agreement at advance ratios below 0.10. Comparisons with flight test and model-scale data show good agreement at all advance ratios tested. Propulsive force calculations show good correlation with full-scale wind tunnel data at advance ratios of 0.10 to 0.19.
C1 NASA, Ames Res Ctr, Rotorcraft Div,AMRDEC, Aeroflightdynam Directorate,USA Res Dev & Engn Co, Moffett Field, CA 94035 USA.
NASA, Ames Res Ctr, Raytheon ITSS, Moffett Field, CA 94035 USA.
RP Shinoda, PM (reprint author), NASA, Ames Res Ctr, Rotorcraft Div,AMRDEC, Aeroflightdynam Directorate,USA Res Dev & Engn Co, Moffett Field, CA 94035 USA.
NR 28
TC 8
Z9 8
U1 0
U2 0
PU AMER HELICOPTER SOC INC
PI ALEXANDRIA
PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA
SN 0002-8711
J9 J AM HELICOPTER SOC
JI J. Am. Helicopter Soc.
PD OCT
PY 2004
VL 49
IS 4
BP 401
EP 413
PG 13
WC Engineering, Aerospace
SC Engineering
GA 866JX
UT WOS:000224770900003
ER
PT J
AU Paris, IL
Krueger, R
O'Brien, TK
AF Paris, IL
Krueger, R
O'Brien, TK
TI Effect of assumed damage and location on delamination onset for
skin-stiffener debonding
SO JOURNAL OF THE AMERICAN HELICOPTER SOCIETY
LA English
DT Article; Proceedings Paper
CT Meeting of the American-Helicopter-Society-Structures-Specialists
CY OCT 30-NOV 01, 2001
CL Williamsburg, VA
AB The difference in delamination onset predictions based on the type and location of the assumed initial damage are compared in a specimen consisting of a tapered flange laminate bonded to a skin laminate. From previous experimental work, the damage was identified to consist of a matrix crack in the top skin layer followed by a delamination between the top and second skin layer (+45degrees/-45degrees interface). Two-dimensional finite elements analyses were performed for three different assumed flaws and the results show a considerable reduction in critical load if an initial delamination is assumed to be present, both under tension and bending loads. For a crack length corresponding to the peak in the strain energy release rate, the delamination onset load for an assumed initial flaw in the bondline is slightly higher than the critical load for delamination onset from an assumed skin matrix crack, both under tension and bending loads. As a result, assuming an initial flaw in the bondline is simpler while providing a critical load relatively close to the real case. For the configuration studied, a small delamination might form at a lower tension load than the critical load calculated for a 12.7 mm (0.5") delamination, but it would grow in a stable manner. For the bending case, assuming an initial flaw of 12.7 mm (0.5") is conservative, but the crack would grow unstably.
C1 NASA, Langley Res Ctr, USA Res Lab, Vehicle Technol Directorate, Hampton, VA 23665 USA.
Natl Inst Aerosp, Hampton, VA USA.
RP Paris, IL (reprint author), NASA, Langley Res Ctr, USA Res Lab, Vehicle Technol Directorate, Hampton, VA 23665 USA.
RI Krueger, Ronald/G-5356-2015
NR 7
TC 1
Z9 1
U1 0
U2 0
PU AMER HELICOPTER SOC INC
PI ALEXANDRIA
PA 217 N WASHINGTON ST, ALEXANDRIA, VA 22314 USA
SN 0002-8711
J9 J AM HELICOPTER SOC
JI J. Am. Helicopter Soc.
PD OCT
PY 2004
VL 49
IS 4
BP 501
EP 507
PG 7
WC Engineering, Aerospace
SC Engineering
GA 866JX
UT WOS:000224770900012
ER
PT J
AU Seywald, H
Roithmayr, CM
Mazanek, DD
Stillwagen, FH
Troutman, PA
Park, SY
AF Seywald, H
Roithmayr, CM
Mazanek, DD
Stillwagen, FH
Troutman, PA
Park, SY
TI Planar high-thrust and low thrust orbital transfers from Earth to Europa
SO JOURNAL OF THE ASTRONAUTICAL SCIENCES
LA English
DT Article; Proceedings Paper
CT AAS/AIAA 13th Space Flight Mechanics Meeting
CY FEB 09-13, 2003
CL Ponce, PR
SP AAS, Amer Inst Aeronaut & Astronaut
ID PROPULSION
AB We review analytical formulae for low-thrust orbital transfers from a circular initial orbit to a circular target orbit and to escape, using constant thrust applied in the same direction as the velocity vector, or in the opposite direction. The formulae give approximations for the maneuver time, final mass fraction, and evolution of the semimajor axis. For comparison, the associated results for high-thrust Hohmann and Oberth transfers are summarized. A simple computer program employing the aforementioned relationships is a useful tool for analysis of planar planetary and interplanetary space missions. This implementation yields fast and reasonably accurate approximations to trajectory performance boundaries. Consequently, the approach can provide trajectory analysis for each spacecraft configuration during the conceptual space mission design phase. As an example, a mission from Low-Earth Orbit (LEO) to Jupiter's moon Europa is analyzed.
C1 Yonsei Univ, Dept Astron, Ctr Astrodynam & Space Technol, Seoul 120749, South Korea.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
Analyt Mech Associates Inc, Hampton, VA 23665 USA.
RP Seywald, H (reprint author), Yonsei Univ, Dept Astron, Ctr Astrodynam & Space Technol, Seoul 120749, South Korea.
EM seywald@ama-inc.com; c.m.roithmayr@larc.nasa.gov;
d.d.mazanek@larc.nasa.gov; f.h.stillwagen@larc.nasa.gov;
p.a.troutman@larc.nasa.gov; spark@galaxy.yonsei.ac.kr
NR 15
TC 0
Z9 0
U1 0
U2 0
PU AMER ASTRONAUTICAL SOC
PI SPRINGFIELD
PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 USA
SN 0021-9142
J9 J ASTRONAUT SCI
JI J. Astronaut. Sci.
PD OCT-DEC
PY 2004
VL 52
IS 4
BP 421
EP 439
PG 19
WC Engineering, Aerospace
SC Engineering
GA 974PY
UT WOS:000232605100001
ER
PT J
AU Bombardelli, C
Lorenzini, EC
Quadrelli, MB
AF Bombardelli, C
Lorenzini, EC
Quadrelli, MB
TI Formation pointing dynamics of tether-connected architecture for space
interferometry
SO JOURNAL OF THE ASTRONAUTICAL SCIENCES
LA English
DT Article; Proceedings Paper
CT AAS/AIAA 13th Space Flight Mechanics Meeting
CY FEB 09-13, 2003
CL Ponce, PR
SP AAS, Amer Inst Aeronaut & Astronaut
ID SATELLITE
AB The baseline pointing dynamics, i.e., the attitude of the instantaneous plane of rotation, of a linear tethered interferometer with single baseline orbiting in an Earth trailing, heliocentric orbit is analyzed. Two tether arms provide a passive control of the spacecraft formation by keeping two light collectors and one combiner aligned while spinning about the boresight of the interferometer. The interferometer optical path delay variation under gravity gradient perturbation and unbalanced solar radiation torque is investigated analytically for a fixed-length dumbbell model. Analytical results are compared with results from numerical simulations of a visco-elastic massive tether model in order to assess the effect of the tether dynamics on the pointing stability of the formation. The study highlights the fundamental role of spin stabilization in counteracting the effect of external perturbation on the interferometer Optical Path Delay (OPD).
C1 Univ Padua, Fac Mech Engn, CISAS, Padua, Italy.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA.
RP Bombardelli, C (reprint author), Univ Padua, Fac Mech Engn, CISAS, Padua, Italy.
NR 18
TC 5
Z9 5
U1 0
U2 3
PU AMER ASTRONAUTICAL SOC
PI SPRINGFIELD
PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 USA
SN 0021-9142
J9 J ASTRONAUT SCI
JI J. Astronaut. Sci.
PD OCT-DEC
PY 2004
VL 52
IS 4
BP 475
EP 493
PG 19
WC Engineering, Aerospace
SC Engineering
GA 974PY
UT WOS:000232605100004
ER
PT J
AU Ploen, SR
Scharf, DP
Hadaegh, FY
Bikdash, M
AF Ploen, SR
Scharf, DP
Hadaegh, FY
Bikdash, M
TI Initialization of distributed spacecraft formations
SO JOURNAL OF THE ASTRONAUTICAL SCIENCES
LA English
DT Article; Proceedings Paper
CT AAS/AIAA 13th Space Flight Mechanics Meeting
CY FEB 09-13, 2003
CL Ponce, PR
SP AAS, Amer Inst Aeronaut & Astronaut
ID FORMATION FLYING GUIDANCE
AB In this paper, a solution to the formation initialization (FI) problem for N distributed spacecraft located in deep space is presented. The solution is based on a three-phase sky search procedure that reduces the formation initialization problem for N distributed spacecraft to the simpler problem of initializing a set of sub-formations. An analytical proof demonstrating that the algorithm guarantees formation initialization for N spacecraft constrained to a plane is presented. An upper bound on the time to initialize a planar formation is also provided. Finally, the FI algorithm is demonstrated in simulation using NASA's five-spacecraft Terrestrial Planet Finder (TPF) mission as an example.
C1 CALTECH, Jet Propuls Lab, Guidance & Control Anal Grp, Pasadena, CA 91109 USA.
N Carolina Agr & Tech State Univ, Dept Elect & Comp Engn, Greensboro, NC 27411 USA.
RP Ploen, SR (reprint author), CALTECH, Jet Propuls Lab, Guidance & Control Anal Grp, 4800 Oak Grove Dr,Mail Stop 198-326, Pasadena, CA 91109 USA.
EM scott.r.ploen@jpl.nasa.gov; daniel.p.scharf@jpl.nasa.gov;
hadaegh@jpl.nasa.gov; bikdash@ncat.edu
NR 8
TC 2
Z9 2
U1 0
U2 0
PU AMER ASTRONAUTICAL SOC
PI SPRINGFIELD
PA 6352 ROLLING MILL PLACE SUITE 102, SPRINGFIELD, VA 22152 USA
SN 0021-9142
J9 J ASTRONAUT SCI
JI J. Astronaut. Sci.
PD OCT-DEC
PY 2004
VL 52
IS 4
BP 495
EP 515
PG 21
WC Engineering, Aerospace
SC Engineering
GA 974PY
UT WOS:000232605100005
ER
PT J
AU Kuo, KS
Smith, EA
Haddad, Z
Im, E
Iguchi, T
Mugnai, A
AF Kuo, KS
Smith, EA
Haddad, Z
Im, E
Iguchi, T
Mugnai, A
TI Mathematical-physical framework for retrieval of rain DSD properties
from dual-frequency Ku-Ka-band satellite radar
SO JOURNAL OF THE ATMOSPHERIC SCIENCES
LA English
DT Article
ID PATH-INTEGRATED ATTENUATION; TRMM PRECIPITATION RADAR; DROP SIZE
DISTRIBUTION; SPACEBORNE RADAR; MEASURING MISSION; PROFILING ALGORITHM;
SINGLE-FREQUENCY; WAVELENGTH; REFLECTIVITY; AIRBORNE
AB In developing the upcoming Global Precipitation Measurement (GPM) mission, a dual-frequency Ku-Ka-band radar system will be used to measure rainfall in such a fashion that the reflectivity ratio intrinsic to the measurement will be sensitive to underlying variations in the drop size distribution (DSD) of rain. This will enable improved techniques for retrieving rain rates, which are dependent upon several key properties of the DSD. This study examines this problem by considering a three-parameter set defined by liquid water content (W), DSD effective radius (r(e)), and DSD effective variance (v(e)). Using radiative transfer simulations, this parameter set is shown to be related to a radar reflectivity factor and specific attenuation in such a fashion that details of the DSDs are immaterial under constant W, and thus effectively represent important variations in DSD that affect rain rate but with a minimal number of parameters. The analysis also examines the effectiveness of including some measure of mean Doppler fall velocity of raindrops ((v) over bar), given that the fundamental properties of a given precipitation situation are uniquely defined by a combination of a drop mass spectrum and drop vertical velocity spectrum. The results of this study have bearing on how future dual-frequency precipitation retrieval algorithms could be formulated to optimize the sensitivity to underlying DSD variability, a problem that has greatly upheld past progress in radar rain retrieval.
C1 NASA, Goddard Space Flight Ctr, GEST Caelum, Greenbelt, MD 20771 USA.
Caelum Res Corp, Greenbelt, MD USA.
CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91125 USA.
Commun Res Labs, Global Environm Div, Tokyo, Japan.
CNR, Inst Atmospher Sci & Climate, Rome, Italy.
RP Kuo, KS (reprint author), NASA, Goddard Space Flight Ctr, GEST Caelum, Mail Stop 912-1, Greenbelt, MD 20771 USA.
EM kskuo@radar.gsfc.nasa.gov
RI Measurement, Global/C-4698-2015; PMM, JAXA/K-8537-2016
NR 61
TC 9
Z9 9
U1 0
U2 1
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0022-4928
J9 J ATMOS SCI
JI J. Atmos. Sci.
PD OCT
PY 2004
VL 61
IS 19
BP 2349
EP 2369
DI 10.1175/1520-0469(2004)061<2349:MFFROR>2.0.CO;2
PG 21
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 857UU
UT WOS:000224145100003
ER
PT J
AU Tao, WK
Johnson, D
Shie, CL
AF Tao, WK
Johnson, D
Shie, CL
TI The atmospheric energy budget and large-scale precipitation efficiency
of convective systems during TOGA COARE, GATE, SCSMEX, and ARM:
Cloud-resolving model simulations
SO JOURNAL OF THE ATMOSPHERIC SCIENCES
LA English
DT Article
ID SOUTH CHINA SEA; MIDLATITUDE SQUALL LINE; TROPICAL CUMULUS CLOUDS;
LONG-TERM BEHAVIOR; RADIATION INTERACTION; NUMERICAL-SIMULATION; SURFACE
PROCESSES; PART II; BULK PARAMETERIZATION; MESOSCALE PROCESSES
AB A two-dimensional version of the Goddard Cumulus Ensemble ( GCE) model is used to simulate convective systems that developed in various geographic locations ( east Atlantic, west Pacific, South China Sea, and Great Plains in the United States). Observed large-scale advective tendencies for potential temperature, water vapor mixing ratio, and horizontal momentum derived from field campaigns are used as the main forcing. The atmospheric temperature and water vapor budgets from the model results show that the two largest terms are net condensation (heating/drying) and imposed large-scale forcing (cooling/moistening) for tropical oceanic cases though not for midlatitude continental cases. These two terms are opposite in sign, however, and are not the dominant terms in the moist static energy budget.
The balance between net radiation, surface latent heat flux, and net condensational heating vary in these tropical cases, however. For cloud systems that developed over the South China Sea and eastern Atlantic, net radiation ( cooling) is not negligible in the temperature budget; it is as large as 20% of the net condensation. However, shortwave heating and longwave cooling are in balance with each other for cloud systems over the west Pacific region such that the net radiation is very small. This is due to the thick anvil clouds simulated in the cloud systems over the Pacific region. The large-scale advection of moist static energy is negative, as a result of a larger absolute value of large-scale advection of sensible heat ( cooling) compared to large-scale latent heat ( moistening) advection in the Pacific and Atlantic cases. For three cloud systems that developed over a midlatitude continent, the net radiation and sensible and latent heat fluxes play a much more important role. This means that the accurate measurement of surface fluxes and radiation is crucial for simulating these midlatitude cases.
The results showed that large-scale mean (multiday) precipitation efficiency ( PE) varies from 24% to 31% (or 32% to 45% using a different definition of PE) between cloud systems from different geographic locations. The model results showed that there is no clear relationship between the PE and rainfall, the positive cloud condensation ( condensation plus deposition), or the large-scale forcing. But, the model results suggest that cases with large, positive net condensation terms in the moist static energy budget tend to have a large PE.
The PE and its relationship with relative humidity and the vertical shear of the horizontal wind are also examined using 6-hourly model data. The model results suggest that there is no clear relationship between the individual PE and total mass-weighted relative humidity or the middle- and upper-tropospheric moisture for each case. The model results suggest that for the west Pacific and east Atlantic cases, PE slightly decreases with increasing middle- tropospheric wind shear in low to moderate shear regimes. The correlation ( based on the best polynomial fit) is quite weak however. No strong relationship between PE and wind shear was found for the South China Sea and cases over the United States.
C1 NASA, Atmospheres Lab, Mesoscale Atmospher Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
RP NASA, Atmospheres Lab, Mesoscale Atmospher Branch, Goddard Space Flight Ctr, Code 912, Greenbelt, MD 20771 USA.
EM tao@agnes.gsfc.nasa.gov
NR 64
TC 40
Z9 41
U1 1
U2 5
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0022-4928
EI 1520-0469
J9 J ATMOS SCI
JI J. Atmos. Sci.
PD OCT
PY 2004
VL 61
IS 20
BP 2405
EP 2423
DI 10.1175/1520-0469(2004)061<2405:TAEBAL>2.0.CO;2
PG 19
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 863UF
UT WOS:000224588100001
ER
PT J
AU Chamis, CC
AF Chamis, CC
TI Design of smart composite structures in the presence of uncertainties
SO JOURNAL OF THE CHINESE INSTITUTE OF ENGINEERS
LA English
DT Article
DE probability; hybrids; wing; sensitivities
AB A composite wing with spars, bulkheads and built-in control devices is evaluate and designed using a proposed methodology for smart composite structures. The proposed design methodology is probabilistic and accounts for all naturally-occurring uncertainties including those in constituent (fiber/matrix) material properties, fabrication variables, structure geometry and control related parameters. Probabilistic sensitivity factors are computed to identify those parameters that have the great influence on a specific structural reliability. Two performance criteria are used to demonstrate the design methodology. The first criterion requires that the actuated angle at the wing tip be bounded by upper and lower limits at a specified reliability. The second criterion requires that the probability of ply damage due to random impact load be smaller than an assigned value. The correlation between the sensitivity factors and reliability improvement is assessed. The results show that a reduction in the scatter of the random primitive variable with the highest sensitivity factor (absolute value) provides the lowest failure probability and vice versa. An increase in the mean of the primitive variable with the highest sensitivity factor provides the lowest failure probability and vice versa. Therefore, the design can be improved by controlling and adjusting parameters associated with random variables. This can be implemented during the manufacturing process to obtain the "maximum" benefit with minimum alterations.
C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Chamis, CC (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
EM christos.c.chamis@grc.nasa.gov
NR 18
TC 3
Z9 3
U1 0
U2 5
PU CHINESE INST ENGINEERS
PI TAIPEI
PA #1, 4TH FL, SEC 2, JEN-AI RD, TAIPEI 10019, TAIWAN
SN 0253-3839
J9 J CHIN INST ENG
JI J. Chin. Inst. Eng.
PD OCT
PY 2004
VL 27
IS 6
BP 771
EP 781
DI 10.1080/02533839.2004.9670928
PG 11
WC Engineering, Multidisciplinary
SC Engineering
GA 865NB
UT WOS:000224708700005
ER
PT J
AU Yoshizaki, M
Kato, T
Eito, H
Hayashi, S
Tao, WK
AF Yoshizaki, M
Kato, T
Eito, H
Hayashi, S
Tao, WK
TI An overview of the field experiment "Winter mesoscale convective systems
(MCSs) over the Japan Sea in 2001", and comparisons of the cold-air
outbreak case (14 January) between analysis and a non-hydrostatic
cloud-resolving model
SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN
LA English
DT Article
ID POTENTIAL VORTICITY; MOISTURE BUDGETS; HEAT; BAND; CYCLOGENESIS;
CLUSTERS; MONSOON; VORTEX
AB A field experiment of snowfall systems, WMO-01, was conducted over the Japan Sea in the winter of 2001. During the WMO-01 period, cold-air outbreaks and passages of synoptic-scale cyclones were observed several times. By utilizing global analysis (GANAL) data, with a horizontal resolution of 1.25 degrees, the apparent heat source Q(1), apparent moisture sink Q(2), differential advection of moist static energy Dh, potential vorticity PV, sensible heat flux S and latent heat flux L,E were estimated to investigate characteristic features of weather over the Japan Sea. It is shown that the cold-air outbreak during 12 to 17 January was remarkable, where Q 1, upper-level PV, S, L(v)E, and -Dh were the largest during the WMO-01 period. The cold-air was accompanied with the upper-level high PV anomaly, and the air-mass transformation took place strongly over the Japan Sea. The values of S + L(v)E reached approximately 600 Wm(-2), and -Dh was large, indicating that the convective activity was strong. The heat and moisture budgets were compared with previous studies for the Japan Sea in winter. Generally speaking, it is shown that the budgets were similar to previous studies.
Next, the 14 January case was examined in detail as a typical example of the cold-air outbreak. The convergence band (= JPCZ) was found extending southeastward from the east of joint of the Korean Peninsula to the San-in and Hokuriku areas. The L modes of convective clouds (parallel to the prevailing northwesterly wind) were seen on both sides of the JPCZ, and the T modes (normal to the NWly wind) were found on the northeastern side. A synoptic-scale cold trough was seen in eastern Asia at 500 hPa, and the polar jet was located on the southern side of the Japan Sea. Additional 1000 km-size PV anomalies slowly propagated eastward repeatedly along the northern side of the jet.
This case was studied by using a non-hydrostatic cloud-resolving model with 5 km horizontal resolution (5 km-NHM). Characteristic features of the JPCZ were well reproduced. The 5 km-NHM outputs were also used to examine the heat and moisture budgets. Q(1)* and Q(2)* are defined similarly to Q(1) and Q(2), respectively, but the ice phase is included. Large differences from the GANAL analysis were found near the surface and above the height of 4 km. Near the surface, the evaporation of snow or rain may occur for the 5 km-NHM, while it may not for the analyzed Q(1) and Q(2) due to the vertically coarse data. The sensitivity experiments of cases with or without ice phase were also examined. It is found that the general features are similar in both cases, indicating that the ice phase is not very important for the diabatic process of clouds in this study.
C1 Meteorol Res Inst, Forecast Res Dept, Tsukuba, Ibaraki 3050052, Japan.
NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
RP Yoshizaki, M (reprint author), Meteorol Res Inst, Forecast Res Dept, 1-1 Nagamine, Tsukuba, Ibaraki 3050052, Japan.
EM myoshiza@mri-jma.go.jp
NR 43
TC 15
Z9 15
U1 0
U2 4
PU METEOROLOGICAL SOC JPN
PI TOKYO
PA C/O JPN METEOROL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, 100-0004,
JAPAN
SN 0026-1165
J9 J METEOROL SOC JPN
JI J. Meteorol. Soc. Jpn.
PD OCT
PY 2004
VL 82
IS 5
BP 1365
EP 1387
DI 10.2151/jmsj.2004.1365
PG 23
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 881EZ
UT WOS:000225847500007
ER
PT J
AU Pu, ZX
Tao, WK
AF Pu, ZX
Tao, WK
TI Mesoscale assimilation of TMI rainfall data with 4DVAR: Sensitivity
studies
SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN
LA English
DT Article
ID VARIATIONAL DATA ASSIMILATION; PRECIPITATION; MODEL; RESOLUTION;
PROFILES; TESTS
AB Sensitivity studies are performed on the assimilation of TRMM (Tropical Rainfall Measuring Mission) Microwave Imager (TMI) derived rainfall data into a mesoscale model, using a four-dimensional variational data assimilation (4DVAR) technique. A series of numerical experiments is conducted to evaluate the impact of TMI rainfall data on the numerical simulation of Hurricane Bonnie (1998). The results indicate that rainfall data assimilation is sensitive to the error characteristics of the data, and the inclusion of physics in the adjoint model. In addition, assimilating the rainfall data alone is helpful for producing a more realistic eye and rain bands in the hurricane, but does not ensure improvements in hurricane intensity forecasts. Further study indicated that it is necessary to incorporate TMI rainfall data together with other types of data, such as wind data into the model, in which case the inclusion of the rainfall data further improves the intensity forecast of the hurricane.
C1 Univ Maryland Baltimore Cty, NASA, Goddard Space Flight Ctr, Goddard Earth Sci & Technol Ctr, Greenbelt, MD USA.
NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
RP Pu, ZX (reprint author), Univ Utah, Dept Meteorol, 135 S 1460 E,Rm 819, Salt Lake City, UT 84112 USA.
EM pu@met.utah.edu
NR 19
TC 6
Z9 6
U1 0
U2 0
PU METEOROLOGICAL SOC JPN
PI TOKYO
PA C/O JPN METEOROL AGENCY 1-3-4 OTE-MACHI, CHIYODA-KU, TOKYO, JAPAN
SN 0026-1165
J9 J METEOROL SOC JPN
JI J. Meteorol. Soc. Jpn.
PD OCT
PY 2004
VL 82
IS 5
BP 1389
EP 1397
DI 10.2151/jmsj.2004.1389
PG 9
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 881EZ
UT WOS:000225847500008
ER
PT J
AU Williams, RB
Inman, DJ
Wilkie, WK
AF Williams, RB
Inman, DJ
Wilkie, WK
TI Temperature-dependent thermoelastic properties for macro fiber composite
actuators
SO JOURNAL OF THERMAL STRESSES
LA English
DT Article
DE CTE; macro fiber composites; piezoceramic fibers; temperature-dependent
properties
ID THERMAL-EXPANSION; COEFFICIENTS; PREDICTION
AB This research effort models the thermoelastic properties of the macro fiber composite actuator as a function of temperature. The required temperature-dependent properties of each constituent material are obtained, and the orthotropic layer properties are calculated using a variety of micromechanics models, with the most accurate being selected based on a comparison with ANSYS finite element models. Equations for the four independent stiffness parameters and two coefficients of thermal expansion of the entire actuator are derived using a classical lamination approach. These results agree closely with an ANSYS finite element model of the unit cell of the macro fiber composite actuator.
C1 Virginia Polytech Inst & State Univ, CIMSS, Dept Mech Engn, Blacksburg, VA 24061 USA.
NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23665 USA.
RP Williams, RB (reprint author), NASA, Jet Prop Lab, 4800 Oak grove Dr,MS 299-101, Pasadena, CA 91109 USA.
EM rowilli6@jpl.nasa.gov
NR 11
TC 13
Z9 13
U1 0
U2 0
PU TAYLOR & FRANCIS INC
PI PHILADELPHIA
PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA
SN 0149-5739
J9 J THERM STRESSES
JI J. Therm. Stresses
PD OCT
PY 2004
VL 27
IS 10
BP 903
EP 915
DI 10.1080/01495730490498386
PG 13
WC Thermodynamics; Mechanics
SC Thermodynamics; Mechanics
GA 853RA
UT WOS:000223843900002
ER
PT J
AU Park, C
Raiche, GA
Driver, DA
AF Park, C
Raiche, GA
Driver, DA
TI Radiation of spalled particles in shock layers
SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER
LA English
DT Article; Proceedings Paper
CT AIAA 42nd Aerospace Sciences Meeting and Exhibit
CY JAN 05-08, 2004
CL Reno, NV
SP Amer Inst Aeronaut & Astronaut
AB The behavior of solid particles ejected into a shock layer from an ablating carbonaceous heat shield is investigated theoretically in order to explain the results of an experiment conducted in an are-jet facility. The experiment found that a laser beam made to pass through the shock layer over an ablating flat-faced model is attenuated in the shock layer.The likely cause of the attenuation is the presence of solid carbon particles due to spallation. The equation of motion of the solid particles, accounting for their vaporization, is integrated for different combinations of size and ejection velocity. The assumed quantity of ejected particles and the distributions of the size and ejection velocity are varied until the calculated pattern of laser-beam attenuation matched the experimental data. The radiative heat flux reaching the wall is calculated to be up to 170 W/cm(2) in the arc-jet experiment. If this phenomenon occurs also during the entry flight of the Stardust vehicle, the wall-heating rates are predicted to be up to 8% greater than without radiating carbon particles in the shock layer.
C1 Eloret Corp, Sunnyvale, CA 94087 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Park, C (reprint author), Korea Adv Inst Sci & Technol, Dept Aerosp Engn, Taejon 305701, South Korea.
EM cpark216@kaist.ac.kr
NR 15
TC 13
Z9 13
U1 0
U2 0
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0887-8722
J9 J THERMOPHYS HEAT TR
JI J. Thermophys. Heat Transf.
PD OCT-DEC
PY 2004
VL 18
IS 4
BP 519
EP 526
DI 10.2514/1.8098
PG 8
WC Thermodynamics; Engineering, Mechanical
SC Thermodynamics; Engineering
GA 866JP
UT WOS:000224770100012
ER
PT J
AU Bose, D
Wright, MJ
AF Bose, D
Wright, MJ
TI View-factor-based radiation transport in a hypersonic shock layer
SO JOURNAL OF THERMOPHYSICS AND HEAT TRANSFER
LA English
DT Article
C1 NASA, Ames Res Ctr, Reacting Flow Environm Branch, Moffett Field, CA 94035 USA.
RP Bose, D (reprint author), NASA, Ames Res Ctr, ELORET Corp, Mail Stop 230-3, Moffett Field, CA 94035 USA.
NR 5
TC 7
Z9 7
U1 0
U2 0
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0887-8722
J9 J THERMOPHYS HEAT TR
JI J. Thermophys. Heat Transf.
PD OCT-DEC
PY 2004
VL 18
IS 4
BP 553
EP 555
DI 10.2514/1.8817
PG 3
WC Thermodynamics; Engineering, Mechanical
SC Thermodynamics; Engineering
GA 866JP
UT WOS:000224770100017
ER
PT J
AU Balazs, GH
Chaloupka, M
AF Balazs, GH
Chaloupka, M
TI Spatial and temporal variability in somatic growth of green sea turtles
(Chelonia mydas) resident in the Hawaiian Archipelago
SO MARINE BIOLOGY
LA English
DT Article
ID GREAT-BARRIER-REEF; FORAGING AREA; ISLANDS; RATES; FIBROPAPILLOMATOSIS;
MODELS
AB The somatic growth dynamics of green turtles ( Chelonia mydas) resident in five separate foraging grounds within the Hawaiian Archipelago were assessed using a robust non-parametric regression modelling approach. The foraging grounds range from coral reef habitats at the north-western end of the archipelago, to coastal habitats around the main islands at the southeastern end of the archipelago. Pelagic juveniles recruit to these neritic foraging grounds from ca. 35 cm SCL or 5 kg ( similar to 6 years of age), but grow at foraging-ground-specific rates, which results in quite different size- and age-specific growth rate functions. Growth rates were estimated for the five populations as change in straight carapace length ( cm SCL year) 1) and, for two of the populations, also as change in body mass ( kg year) 1). Expected growth rates varied from ca. 0 - 2.5 cm SCL year) 1, depending on the foraging-ground population, which is indicative of slow growth and decades to sexual maturity, since expected size of first-time nesters is greater than or equal to 80 cm SCL. The expected size- specific growth rate functions for four populations sampled in the southeastern archipelago displayed a non-monotonic function, with an immature growth spurt at ca. 50 - 53 cm SCL ( similar to 18 - 23 kg) or ca. 13 - 19 years of age. The growth spurt for the Midway atoll population in the northwestern archipelago occurs at a much larger size ( ca. 65 cm SCL or 36 kg), because of slower immature growth rates that might be due to a limited food stock and cooler sea surface temperature. Expected age-at-maturity was estimated to be ca. 35 - 40 years for the four populations sampled at the south-eastern end of the archipelago, but it might well be > 50 years for the Midway population. The Hawaiian stock comprises mainly the same mtDNA haplotype, with no differences in mtDNA stock composition between foraging-ground populations, so that the geographic variability in somatic growth rates within the archipelago is more likely due to local environmental factors rather than genetic factors. Significant temporal variability was also evident, with expected growth rates declining over the last 10 - 20 years, while green turtle abundance within the archipelago has increased significantly since the mid-1970s. This inverse relationship between somatic growth rates and population abundance suggests a density-dependent effect on somatic growth dynamics that has also been reported recently for a Caribbean green turtle stock. The Hawaiian green turtle stock is characterised by slow growth rates displaying significant spatial and temporal variation and an immature growth spurt. This is consistent with similar findings for a Great Barrier Reef green turtle stock that also comprises many foraging-ground populations spanning a wide geographic range.
C1 Univ Queensland, Sch Econ, Brisbane, Qld 4072, Australia.
Natl Marine Fisheries Serv, Pacific Isl Fisheries Sci Ctr, Honolulu, HI 96822 USA.
RP Chaloupka, M (reprint author), Univ Queensland, Sch Econ, Brisbane, Qld 4072, Australia.
EM m.chaloupka@uq.edu.au
NR 55
TC 65
Z9 78
U1 2
U2 28
PU SPRINGER
PI NEW YORK
PA 233 SPRING STREET, NEW YORK, NY 10013 USA
SN 0025-3162
J9 MAR BIOL
JI Mar. Biol.
PD OCT
PY 2004
VL 145
IS 5
BP 1043
EP 1059
DI 10.1007/s00227-004-1387-6
PG 17
WC Marine & Freshwater Biology
SC Marine & Freshwater Biology
GA 864EI
UT WOS:000224616200020
ER
PT J
AU Mullin, KD
Fulling, GL
AF Mullin, KD
Fulling, GL
TI Abundance of cetaceans in the oceanic northern Gulf of Mexico, 1996-2001
SO MARINE MAMMAL SCIENCE
LA English
DT Article
DE abundance; assessment; cetacean; Gulf of Mexico; line-transect; ship
survey
ID EASTERN TROPICAL PACIFIC; CONTINENTAL-SLOPE; DOLPHIN HABITATS; WATERS;
ECOSYSTEMS; SUMMER; AERIAL; POWER
AB The Gulf of Mexico is a Subtropical marginal sea of the western North Atlantic Ocean with a diverse cetacean community. Ship-based, line-transect abundance surveys were conducted in oceanic waters ( > 200 m deep) of the northern Gulf within U.S. waters (380,432 km(2)) during spring from 1996 to 1997 and from 1999 to 2001. Data from these five Surveys were pooled and minimum abundance estimates were based on 12,162 km of effort and 512 sightings of at least 19 species. The most commonly sighted species (number of groups) were pantropical spotted dolphin, Stenella attenuata (164); sperm whale, Physeter macrocephalus (67); dwarf/pygmy sperm whale, Kogia sima/breviceps (58); Risso's dolphin, Grampus griseus (38); and bottlenose dolphin, Tursiops truncatus (24). The most abundant species (number of individuals; coefficient of variation) were S. attenuata (91,321; 0.16); Clymene dolphin, S. clymene (17,355; 0.65); spinner dolphin, S. longirostris (11,971; 0.71); and striped dolphin, S. coeruleoalba (6,505; 0.43). The only large whales sighted were P macrocephalus (1,349; 0.23) and Bryde's whale, Balaenoptera edeni (40; 0.61). Abundances for other species or genera ranged from 95 to 2,388 animals. Cetaceans were sighted throughout the oceanic northern Gulf and, whereas many species were widely distributed, some had more regional distributions.
C1 NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Pascagoula, MS 39567 USA.
RP NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, 3209 Frederic St, Pascagoula, MS 39567 USA.
EM keith.d.mullin@noaa.gov
NR 55
TC 36
Z9 49
U1 0
U2 12
PU WILEY-BLACKWELL
PI HOBOKEN
PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA
SN 0824-0469
EI 1748-7692
J9 MAR MAMMAL SCI
JI Mar. Mamm. Sci.
PD OCT
PY 2004
VL 20
IS 4
BP 787
EP 807
DI 10.1111/j.1748-7692.2004.tb01193.x
PG 21
WC Marine & Freshwater Biology; Zoology
SC Marine & Freshwater Biology; Zoology
GA 862KH
UT WOS:000224489000007
ER
PT J
AU Reif, JS
Bachand, A
Aguirre, AA
Borjesson, DL
Kashinsky, L
Braun, RR
Antonelis, G
AF Reif, JS
Bachand, A
Aguirre, AA
Borjesson, DL
Kashinsky, L
Braun, RR
Antonelis, G
TI Morphometry, hematology, and serum chemistry in the Hawaiian monk seal
(Monachus schauinslandi)
SO MARINE MAMMAL SCIENCE
LA English
DT Article
DE Hawaiian monk seal; Monachus schauinslandi; hematology; serum chemistry;
free-ranging; health
AB We studied morphometric, hematology, and serum chemistry variables in 140 Hawaiian monk seals (Monachus schauinslandi) to establish normal baseline values for these variables among free-living seals. We compared seals at French Frigate Shoals (FFS), Midway Atoll (MID), and Pearl and Hermes Reef (PHR) because these subpopulations differ in their rates Of Population recovery. Dorsal standard length and axillary girth differed significantly between immature (1-4 yr old) and adult ( greater than or equal to 5 yr old) seals among sex and island subgroups. Immature seals at FFS were shorter than those at MID and PHR; adult seals at FFS had smaller dorsal standard lengths and axillary girths compared to the other subpopulations. The differences in size were more pronounced among adult females. Significant differences were also found for hematology and serum chemistry variables among seals at FFS, MID, and PHR. Monk seals at FFS had an absolute lymphopenia and eosinopenia compared to those at MID and PHR, compatible with a stress response. Seals at FFS also had lower blood urea nitrogen than seals at PHR, and a lower plasma potassium than seals at MID or PHR. Monk seals had an absolute and relative eosinophilia compared to previously published values. Analysis of subpopulation differences is useful for population health assessment and for long-term monitoring of an endangered species.
C1 Colorado State Univ, Dept Environm Hlth, Ft Collins, CO 80523 USA.
Columbia Univ, Wildlife Trust, Palisades, NY 10964 USA.
Univ Calif Davis, Sch Vet Med, Dept Pathol Microbiol & Immunol, Davis, CA 95616 USA.
Joint Inst Marine & Atmospher Res, Honolulu, HI 96822 USA.
Natl Marine Fisheries Serv, Honolulu Lab, Honolulu, HI 96822 USA.
RP Reif, JS (reprint author), Colorado State Univ, Dept Environm Hlth, Ft Collins, CO 80523 USA.
EM john.reif@colostate.edu
NR 13
TC 7
Z9 11
U1 1
U2 7
PU SOC MARINE MAMMALOGY
PI LAWRENCE
PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA
SN 0824-0469
J9 MAR MAMMAL SCI
JI Mar. Mamm. Sci.
PD OCT
PY 2004
VL 20
IS 4
BP 851
EP 860
DI 10.1111/j.1748-7692.2004.tb01196.x
PG 10
WC Marine & Freshwater Biology; Zoology
SC Marine & Freshwater Biology; Zoology
GA 862KH
UT WOS:000224489000010
ER
PT J
AU Harting, A
Baker, J
Becker, B
AF Harting, A
Baker, J
Becker, B
TI Non-metrical digital photoidentification system for the Hawaiian monk
seal
SO MARINE MAMMAL SCIENCE
LA English
DT Article
ID DOLPHIN IDENTIFICATION
C1 Harting Biol Consulting, Bozeman, MT 59715 USA.
NOAA, Natl Marine Fisheries Serv, Pacific Isl Fisheries Sci Ctr, Honolulu, HI 96822 USA.
RP Harting, A (reprint author), Harting Biol Consulting, 8898 Sandy Creek Lane, Bozeman, MT 59715 USA.
EM harting@mcn.net
NR 13
TC 15
Z9 18
U1 0
U2 2
PU SOC MARINE MAMMALOGY
PI LAWRENCE
PA 1041 NEW HAMPSHIRE ST, LAWRENCE, KS 66044 USA
SN 0824-0469
J9 MAR MAMMAL SCI
JI Mar. Mamm. Sci.
PD OCT
PY 2004
VL 20
IS 4
BP 886
EP 895
DI 10.1111/j.1748-7692.2004.tb01200.x
PG 10
WC Marine & Freshwater Biology; Zoology
SC Marine & Freshwater Biology; Zoology
GA 862KH
UT WOS:000224489000014
ER
PT J
AU Wernet, MP
AF Wernet, MP
TI Planar particle imaging Doppler velocimetry: a hybrid PIV/DGV technique
for three-component velocity measurements
SO MEASUREMENT SCIENCE AND TECHNOLOGY
LA English
DT Article
DE fluid flow velocity; particle image velocimetry; Doppler shift; planar
Doppler velocimetry; Doppler global velocimetry; combustion diagnostics;
aeroacoustics; compressor research; wind tunnel testing
ID HIGH-SPEED FLOWS
AB Digital particle imaging velocimetry (DPIV) is a high resolution, high accuracy, planar velocimetry technique, which provides valuable instantaneous velocity information in aeropropulsion test facilities. DPIV is capable of providing three-component flow field measurements using a two-camera, stereo viewing configuration. Doppler global velocimetry (DGV) is another planar velocimetry technique which is also capable of providing three-component flow field measurements, but requires three detector systems that must be located at oblique angles from the measurement plane. The three-dimensional (3D) configurations of either technique require multiple (DGV) or at least large (stereo PIV) optical access ports in the facility in which the measurements are being conducted. In some test facilities, only limited optical access is available (either a single viewing window or small optical access port), which prohibits the implementation of either technique for three-component flow measurements. A hybrid measurement technique is described, called planar particle image Doppler velocimetry (PPIDV), which combines elements from both the DPIV and DGV techniques into a single detection system. The resulting system is capable of measuring all three components of velocity across a planar region of a flow field through a single optical access port. An error analysis is performed which reveals an optimal configuration for the DGV portion of the measurement system. Measurements of a rotating wheel are used to verify the integrity of the technique. Then simultaneous measurements of a nozzle flow are obtained using both a stereo viewing DPIV system and the PPIDV system.
C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP NASA, Glenn Res Ctr, MS-77-1,21000 Brookpk Rd, Cleveland, OH 44135 USA.
EM mark.p.wernet@nasa.gov
NR 17
TC 11
Z9 12
U1 0
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0957-0233
EI 1361-6501
J9 MEAS SCI TECHNOL
JI Meas. Sci. Technol.
PD OCT
PY 2004
VL 15
IS 10
BP 2011
EP 2028
AR PII S0957-0233(04)77898-4
DI 10.1088/0957-0233/15/10/011
PG 18
WC Engineering, Multidisciplinary; Instruments & Instrumentation
SC Engineering; Instruments & Instrumentation
GA 867OZ
UT WOS:000224853200012
ER
PT J
AU Edge, WRT
Coe, MJ
Galache, JL
McBride, VA
Corbet, RHD
Markwardt, CB
Laycock, S
AF Edge, WRT
Coe, MJ
Galache, JL
McBride, VA
Corbet, RHD
Markwardt, CB
Laycock, S
TI Three new X-ray pulsars detected in the Small Magellanic Cloud and the
positions of two other known pulsars determined
SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
LA English
DT Article
DE stars : emission-line, Be; Magellanic Clouds; X-rays : binaries
ID BINARIES; CATALOG; STARS; SMC
AB Three new X-ray pulsars have been detected in the Small Magellanic Cloud (SMC) and the positions of two others have been determined, with archive Chandra data. A series of five observations of the SMC took place between 2002 May and October. Analysis of these data has revealed three previously unknown X-ray pulsars at pulse periods of 34, 503 and 138 s. The position of pulsar XTE J0052-725, which was originally detected by RXTE on 2002 June 19, was also accurately determined and a previously detected 7.78-s RXTE pulsar was identified as the source SMC X-3.
C1 Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Space Res Assoc, Columbia, MD 21044 USA.
Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
RP Edge, WRT (reprint author), Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England.
EM wrte@astro.soton.ac.uk
NR 23
TC 23
Z9 23
U1 0
U2 1
PU BLACKWELL PUBLISHING LTD
PI OXFORD
PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND
SN 0035-8711
J9 MON NOT R ASTRON SOC
JI Mon. Not. Roy. Astron. Soc.
PD OCT 1
PY 2004
VL 353
IS 4
BP 1286
EP 1292
DI 10.1111/j.1365-2966.2004.08150.x
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 860ZL
UT WOS:000224385800024
ER
PT J
AU Ryan, MA
Shevade, AV
Zhou, H
Homer, ML
AF Ryan, MA
Shevade, AV
Zhou, H
Homer, ML
TI Polymer-carbon black composite sensors in an electronic nose for
air-quality monitoring
SO MRS BULLETIN
LA English
DT Article
DE chemical sensors; electronic noses; polymer-carbon black composite
sensors
ID CHEMICAL SENSORS; RESISTORS; COATINGS; ARRAYS
AB An electronic nose that uses an array of 32 polymer-carbon black composite sensors has been developed, trained, and tested. By selecting a variety of chemical functionalities in the polymers used to make sensors, it is possible to construct an array capable of identifying and quantifying a broad range of target compounds, such as alcohols and aromatics, and distinguishing isomers and enantiomers (mirror-image isomers). A model of the interaction between target molecules and the polymer-carbon black composite sensors is under development to aid in selecting the array members and to enable identification of compounds with responses not stored in the analysis library.
C1 CALTECH, Jet Prop Lab, Elect Nose Project, Pasadena, CA 91109 USA.
RP Ryan, MA (reprint author), CALTECH, Jet Prop Lab, Elect Nose Project, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
NR 17
TC 31
Z9 32
U1 1
U2 6
PU MATERIALS RESEARCH SOCIETY
PI WARRENDALE
PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA
SN 0883-7694
J9 MRS BULL
JI MRS Bull.
PD OCT
PY 2004
VL 29
IS 10
BP 714
EP 719
DI 10.1557/mrs2004.208
PG 6
WC Materials Science, Multidisciplinary; Physics, Applied
SC Materials Science; Physics
GA 863BF
UT WOS:000224534500022
PM 15991400
ER
PT J
AU Wei, CY
Srivastava, D
Cho, K
AF Wei, CY
Srivastava, D
Cho, K
TI Structural ordering in nanotube polymer composites
SO NANO LETTERS
LA English
DT Article
ID CARBON NANOTUBE; MOLECULAR-DYNAMICS; EPOXY COMPOSITES; LOAD-TRANSFER;
SIMULATION; STRENGTH; FILMS
AB The structural properties of carbon nanotube (CNT) polymer composite interfaces have been studied through molecular dynamics simulations. Polymer (polyethylene) molecules are found to form discrete adsorption layers as a function of radial distance from the axis of the nanotube. The molecules within the adsorption layers prefer to align parallel to the tube axis. A structural order parameter of orientation, S-Z, has been investigated in detail and shows a discrete peaking behavior that is in correlation with the peaks in the density distribution function. An increase in the structural order parameter has been shown to contribute to the mechanical modulus of the composite, and the orientation-related changes have been found to be inelastic in nature.
C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Stanford Univ, Dept Engn Mech, Stanford, CA 94305 USA.
RP Wei, CY (reprint author), NASA, Ames Res Ctr, MS 229-1, Moffett Field, CA 94035 USA.
EM cwei@nas.nasa.gov
NR 25
TC 54
Z9 54
U1 7
U2 22
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 1530-6984
J9 NANO LETT
JI Nano Lett.
PD OCT
PY 2004
VL 4
IS 10
BP 1949
EP 1952
DI 10.1021/nl048845m
PG 4
WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience &
Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied;
Physics, Condensed Matter
SC Chemistry; Science & Technology - Other Topics; Materials Science;
Physics
GA 862TU
UT WOS:000224514800025
ER
PT J
AU Weber, AL
AF Weber, AL
TI Kinetics of organic transformations under mild aqueous conditions:
Implications for the origin of life and its metabolism
SO ORIGINS OF LIFE AND EVOLUTION OF THE BIOSPHERE
LA English
DT Review
DE kinetics; reactivity; carbonyl group; metabolism; biosynthesis; sugar
chemistry; diffusion; prebiotic synthesis; molecular evolution
ID HIGH-TEMPERATURE CHEMISTRY; MONOSUBSTITUTED BENZENES; LIPID BILAYERS;
DECARBOXYLATION KINETICS; HYDROTHERMAL REACTIONS; SUPERCRITICAL WATER;
RETROALDOL REACTION; PREBIOTIC SYNTHESIS; CHEMICAL EVOLUTION;
SUPERHEATED WATER
AB The rates of thermal transformation of organic molecules containing carbon, hydrogen, and oxygen were systematically examined in order to identify the kinetic constraints that governed origin-of-life organic chemistry under mild aqueous conditions. Arrhenius plots of the kinetic data were used to estimate the reaction of half-lifes at 50 degreesC. This survey showed that hydrocarbons and organic substances containing a single oxygenated group were kinetically the most stable; whereas organic substances containing two oxygenated groups in which one group was an alpha- or beta-positioned carbonyl group were the most reactive. Compounds with an alpha- or beta-positioned carbonyl group ( aldehyde or ketone) had rates of reaction that were up to 10(24)-times faster than rates of similar molecules lacking the carbonyl group. This survey of organic reactivity, together with estimates of the molecular containment properties of lipid vesicles and liquid spherules, indicates that an origins process in a small domain that used C, H, O-intermediates had to be catalytic and use the most reactive organic molecules to prevent escape of its reaction intermediates.
C1 NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA.
RP Weber, AL (reprint author), NASA, Ames Res Ctr, SETI Inst, Mail Stop 239-4, Moffett Field, CA 94035 USA.
EM aweber@mail.arc.nasa.gov
NR 112
TC 15
Z9 15
U1 1
U2 16
PU KLUWER ACADEMIC PUBL
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0169-6149
J9 ORIGINS LIFE EVOL B
JI Orig. Life Evol. Biosph.
PD OCT
PY 2004
VL 34
IS 5
BP 473
EP 495
DI 10.1023/B:ORIG.0000043128.30559.fe
PG 23
WC Biology
SC Life Sciences & Biomedicine - Other Topics
GA 857PH
UT WOS:000224130300004
PM 15573498
ER
PT J
AU Ogbuji, LU
AF Ogbuji, LU
TI The oxidation behavior of an ODS copper alloy Cu-Al2O3
SO OXIDATION OF METALS
LA English
DT Article
DE Glidcop AL-15; Cu alloys; two-step oxidation; kinetics retardation
ID KINETICS
AB The oxidation behavior of Glidcop AL-15 (Cu-O.3 wt.% Al2O3), an ODS copper alloy of interest for aerospace structural application, was investigated by oxidation and two-step oxidation in a TGA. The results were compared with the oxidation kinetics of pure Cu and two other aerospace Cu alloys, GRCop-84 (Cu-8Cr-4Nb) and NARloy-Z (Cu-3 Ag-O.5Zr). AL-15 exhibited the lowest oxidation rate from 500 to 650degreesC. The superiority in oxidation resistance is thought to result from the Al2O3, and the two-step oxidation results suggest the Al2O3 dissolves in the oxide scale, perhaps creating charge and stress fields that suppress oxidation by retarding the Cu diffusion rate.
C1 QSS Inc, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Ogbuji, LU (reprint author), QSS Inc, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
NR 18
TC 2
Z9 2
U1 1
U2 7
PU KLUWER ACADEMIC/PLENUM PUBL
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 0030-770X
J9 OXID MET
JI Oxid. Met.
PD OCT
PY 2004
VL 62
IS 3-4
BP 141
EP 151
DI 10.1007/s11085-004-7804-x
PG 11
WC Metallurgy & Metallurgical Engineering
SC Metallurgy & Metallurgical Engineering
GA 869NW
UT WOS:000224992300001
ER
PT J
AU Welch, RB
Post, RB
Lum, W
Prinzmetal, W
AF Welch, RB
Post, RB
Lum, W
Prinzmetal, W
TI The relationship between perceived length and egocentric location in
Muller-Lyer figures with one versus two chevrons
SO PERCEPTION & PSYCHOPHYSICS
LA English
DT Article
ID ILLUSIONS; DISSOCIATION; PERCEPTION; DIRECTION; POSITION; EXTENT; SIZE
AB We examined the apparent dissociation of perceived length and perceived position with respect to the Muller-Lyer (M-L) illusion. With the traditional (two-chevron) figure, participants made accurate open-loop pointing responses at the endpoints of the shaft, despite the presence of a strong length illusion. This apparently non-Euclidean outcome replicated that of Mack, Heuer, Villardi, and Chambers (1985) and Gillam and Chambers (1985) and contradicts any theory of the M-L illusion in which mislocalization of shaft endpoints plays a role. However, when one of the chevrons was removed, a constant pointing error occurred in the predicted direction, as well as a strong length illusion. Thus, with one-chevron stimuli, perceived length and location were no longer completely dissociated. We speculated that the presence of two opposing chevrons suppresses the mislocalizing effects of a single chevron, especially for figures with relatively short shafts.
C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Univ Calif Davis, Davis, CA 95616 USA.
Calif State Univ, San Jose, CA USA.
Univ Calif Berkeley, Berkeley, CA 94720 USA.
RP Welch, RB (reprint author), NASA, Ames Res Ctr, Mail Stop 262-2, Moffett Field, CA 94035 USA.
EM robert.b.welch@nasa.gov
NR 23
TC 13
Z9 13
U1 0
U2 1
PU PSYCHONOMIC SOC INC
PI AUSTIN
PA 1710 FORTVIEW RD, AUSTIN, TX 78704 USA
SN 0031-5117
J9 PERCEPT PSYCHOPHYS
JI Percept. Psychophys.
PD OCT
PY 2004
VL 66
IS 7
BP 1095
EP 1104
DI 10.3758/BF03196838
PG 10
WC Psychology; Psychology, Experimental
SC Psychology
GA 894LY
UT WOS:000226794500002
PM 15751468
ER
PT J
AU Shertzer, J
Temkin, A
AF Shertzer, J
Temkin, A
TI Direct calculation of the scattering amplitude without partial-wave
analysis. II. Inclusion of exchange
SO PHYSICAL REVIEW A
LA English
DT Article
ID FINITE-ELEMENT ANALYSIS
AB The development of a practical method of accurately calculating the full scattering amplitude, without making a partial-wave decomposition is continued. The method is developed in the context of electron-hydrogen scattering, and here exchange is dealt with by considering e-H scattering in the static exchange approximation. The Schrodinger equation in this approximation can be simplified to a set of coupled integro-differential equations. The equations are solved numerically for the full scattering wave function. The scattering amplitude can most accurately be calculated from an integral expression for the amplitude; that integral can be formally simplified, and then evaluated using the numerically determined wave function. The results are essentially identical to converged partial-wave results.
C1 Coll Holy Cross, Worcester, MA 01610 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Shertzer, J (reprint author), Coll Holy Cross, Worcester, MA 01610 USA.
NR 6
TC 2
Z9 2
U1 0
U2 0
PU AMERICAN PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 1050-2947
J9 PHYS REV A
JI Phys. Rev. A
PD OCT
PY 2004
VL 70
IS 4
AR 042710
DI 10.1103/PhysRevA.70.042710
PG 5
WC Optics; Physics, Atomic, Molecular & Chemical
SC Optics; Physics
GA 874AE
UT WOS:000225322500054
ER
PT J
AU Boykin, TB
Klimeck, G
Friesen, M
Coppersmith, SN
von Allmen, P
Oyafuso, F
Lee, S
AF Boykin, TB
Klimeck, G
Friesen, M
Coppersmith, SN
von Allmen, P
Oyafuso, F
Lee, S
TI Valley splitting in low-density quantum-confined heterostructures
studied using tight-binding models
SO PHYSICAL REVIEW B
LA English
DT Article
ID HALL SYSTEMS; SEMICONDUCTOR-DEVICES; PHASE-TRANSITIONS;
INVERSION-LAYERS; MAGNETIC-FIELDS; PARAMETERS; TRANSPORT; SIMULATIONS;
SURFACES; CRYSTALS
AB A detailed study of reduced-basis tight-binding models of electrons in semiconducting quantum wells is presented. The focus is on systems with degenerate valleys, such as silicon in silicon germanium heterostructures, in the low-density limit, relevant to proposed quantum computing architectures. Analytic results for the bound states of systems with hard-wall boundaries are presented and used to characterize the valley splitting in silicon quantum wells. The analytic solution in a no-spin-orbit model agrees well with larger tight-binding calculations that do include spin-orbit coupling. Numerical investigations of the valley splitting for finite band offsets are presented that indicate that the hard-wall results are a good guide to the behavior in real quantum wells.
C1 Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Wisconsin, Dept Phys, Madison, WI 53706 USA.
Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA.
Purdue Univ, Sch Elect & Comp Engn, Network Computat Nanotechnol, W Lafayette, IN 47907 USA.
RP Boykin, TB (reprint author), Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA.
RI Klimeck, Gerhard/A-1414-2012
OI Klimeck, Gerhard/0000-0001-7128-773X
NR 47
TC 71
Z9 71
U1 0
U2 3
PU AMERICAN PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 1098-0121
J9 PHYS REV B
JI Phys. Rev. B
PD OCT
PY 2004
VL 70
IS 16
AR 165325
DI 10.1103/PhysRevB.70.165325
PG 12
WC Physics, Condensed Matter
SC Physics
GA 867QB
UT WOS:000224856000074
ER
PT J
AU Rozo, E
Dodelson, S
Frieman, JA
AF Rozo, E
Dodelson, S
Frieman, JA
TI Halo model analysis of cluster statistics
SO PHYSICAL REVIEW D
LA English
DT Article
ID DIGITAL SKY SURVEY; GALAXY FORMATION; LUMINOSITY FUNCTION;
POWER-SPECTRUM; COSMOLOGICAL CONSTRAINTS; OCCUPATION DISTRIBUTION;
COMMISSIONING DATA; ABUNDANCE; NORMALIZATION; MASS
AB We use the halo model formalism to provide expressions for cluster abundances and bias, as well as estimates for the correlation matrix between these observables. Off-diagonal elements due to scatter in the mass-tracer scaling with mass are included, as are observational effects such as biases/scatter in the data, detection rates (completeness), and false detections (purity). We apply the formalism to a hypothetical volume limited optical survey where the cluster mass-tracer is chosen to be the number of satellite galaxies assigned to a cluster. Such a survey can strongly constrain sigma(8) (Deltasigma(8)approximate to0.05), the power law index alpha where =(m/M-1)(alpha) (Deltaalphaapproximate to0.03), and perhaps even the Hubble parameter (Deltahapproximate to0.07). We find cluster abundances and bias are not well suited for constraining Omega(m) or the amplitude M-1. We also find that without bias information sigma(8) and alpha are degenerate, implying constraints on the former are strongly dependent on priors used for the latter and vice-versa. The degeneracy stems from an intrinsic scaling relation of the halo mass function, and hence it should be present regardless of the mass-tracer used in the survey.
C1 Univ Chicago, Dept Phys, Chicago, IL 60637 USA.
Ctr Cosmol Phys, Chicago, IL 60637 USA.
Fermilab Natl Accelerator Lab, NASA, Fermi Astrophys Ctr, Batavia, IL 60510 USA.
Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA.
RP Rozo, E (reprint author), Univ Chicago, Dept Phys, Chicago, IL 60637 USA.
NR 54
TC 9
Z9 9
U1 0
U2 1
PU AMERICAN PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 0556-2821
J9 PHYS REV D
JI Phys. Rev. D
PD OCT
PY 2004
VL 70
IS 8
AR 083008
DI 10.1103/PhysRevD.70.083008
PG 21
WC Astronomy & Astrophysics; Physics, Particles & Fields
SC Astronomy & Astrophysics; Physics
GA 866UX
UT WOS:000224800000016
ER
PT J
AU Shaddock, DA
Ware, B
Spero, RE
Vallisneri, M
AF Shaddock, DA
Ware, B
Spero, RE
Vallisneri, M
TI Postprocessed time-delay interferometry for LISA
SO PHYSICAL REVIEW D
LA English
DT Article
AB High-precision interpolation of LISA phase measurements allows signal reconstruction and formulation of time-delay interferometry (TDI) combinations to be conducted in postprocessing. The reconstruction is based on phase measurements made at approximately 10 Hz (for a 1 Hz signal bandwidth) at regular intervals independent of the TDI delay times. Interpolation introduces an error less than 1x10(-8) with continuous data segments as short as 2 s in duration. The 10 Hz sampling rate represents an increase from the 2 Hz sampling rate needed for the original implementation of TDI. The advantages of this technique include increased flexibility of the data analysis and significantly simplified hardware.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Daniel.Shaddock@jpl.nasa.gov
RI Shaddock, Daniel/A-7534-2011
OI Shaddock, Daniel/0000-0002-6885-3494
NR 11
TC 40
Z9 40
U1 1
U2 3
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 2470-0010
EI 2470-0029
J9 PHYS REV D
JI Phys. Rev. D
PD OCT
PY 2004
VL 70
IS 8
AR 081101
DI 10.1103/PhysRevD.70.081101
PG 5
WC Astronomy & Astrophysics; Physics, Particles & Fields
SC Astronomy & Astrophysics; Physics
GA 866UX
UT WOS:000224800000001
ER
PT J
AU Hattori, Y
Rubinstein, R
Ishizawa, A
AF Hattori, Y
Rubinstein, R
Ishizawa, A
TI Shell model for rotating turbulence
SO PHYSICAL REVIEW E
LA English
DT Article
AB A modified shell model for rotating turbulence is proposed. The effect of rotation is introduced by a randomized linear term. Randomization is shown to be important in correctly modeling the rotation effect. Numerical simulation shows that the exponent of the energy spectrum in the inertial range changes from -5/3 to -2 as rotation rate increases. The mechanism behind this change is explained by weak turbulence theory and supported by numerical results.
C1 Kyushu Inst Technol, Div Comp Aided Sci, Kitakyushu, Fukuoka 8048550, Japan.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
Natl Inst Fus Sci, Theory & Comp Simulat Ctr, Gifu 5095292, Japan.
RP Hattori, Y (reprint author), Kyushu Inst Technol, Div Comp Aided Sci, Kitakyushu, Fukuoka 8048550, Japan.
RI Ishizawa, Akihiro/E-7543-2015
NR 14
TC 18
Z9 18
U1 0
U2 7
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 1539-3755
J9 PHYS REV E
JI Phys. Rev. E
PD OCT
PY 2004
VL 70
IS 4
AR 046311
DI 10.1103/PhysRevE.70.046311
PN 2
PG 6
WC Physics, Fluids & Plasmas; Physics, Mathematical
SC Physics
GA 879AU
UT WOS:000225689600078
PM 15600523
ER
PT J
AU Stairs, IH
Thorsett, SE
Arzoumanian, Z
AF Stairs, IH
Thorsett, SE
Arzoumanian, Z
TI Measurement of gravitational spin-orbit coupling in a binary-pulsar
system
SO PHYSICAL REVIEW LETTERS
LA English
DT Article
ID GEODETIC PRECESSION; RELATIVITY; GRAVITY; PSR-B1534+12; DISCOVERY;
EMISSION; B1913+16; BEAM
AB In relativistic gravity, a spinning pulsar will precess as it orbits a compact companion star. We have measured the effect of such precession on the average shape and polarization of the radiation from PSR B1534+12. We have also detected, with limited precision, special-relativistic aberration of the revolving pulsar beam due to orbital motion. Our observations fix the system geometry, including the misalignment between the spin and orbital angular momenta, and yield a measurement of the precession time scale consistent with the predictions of general relativity.
C1 Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada.
Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA.
NASA, Goddard Space Flight Ctr, USRA, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
RP Stairs, IH (reprint author), Univ British Columbia, Dept Phys & Astron, 6224 Agr Rd, Vancouver, BC V6T 1Z1, Canada.
EM stairs@astro.ubc.ca
NR 23
TC 76
Z9 77
U1 0
U2 1
PU AMERICAN PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 0031-9007
J9 PHYS REV LETT
JI Phys. Rev. Lett.
PD OCT 1
PY 2004
VL 93
IS 14
AR 141101
DI 10.1103/PhysRevLett.93.141101
PG 4
WC Physics, Multidisciplinary
SC Physics
GA 858SL
UT WOS:000224211900010
PM 15524779
ER
PT J
AU Hjorth, J
Kouveliotou, C
Woosley, S
AF Hjorth, J
Kouveliotou, C
Woosley, S
TI Hunting cosmic explosions
SO PHYSICS WORLD
LA English
DT Article
ID GAMMA-RAY BURST; SUPERNOVA
C1 Univ Copenhagen, Astron Observ, Niels Bohr Inst, Copenhagen, Denmark.
NASA, George C Marshall Space Flight Ctr, Natl Space Sci Technol Ctr, Huntsville, AL 35812 USA.
Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA.
RP Hjorth, J (reprint author), Univ Copenhagen, Astron Observ, Niels Bohr Inst, Copenhagen, Denmark.
EM jens@astro.ku.dk
NR 7
TC 0
Z9 0
U1 0
U2 0
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0953-8585
J9 PHYS WORLD
JI Phys. World
PD OCT
PY 2004
VL 17
IS 10
BP 35
EP 39
PG 5
WC Physics, Multidisciplinary
SC Physics
GA 868OK
UT WOS:000224922700034
ER
PT J
AU Clayton, LM
Gerasimov, TG
Cinke, M
Meyyappan, M
Harmon, JP
AF Clayton, LM
Gerasimov, TG
Cinke, M
Meyyappan, M
Harmon, JP
TI Gamma radiation effects on the glass transition temperature and
mechanical properties of PMMA/soot nanocomposites
SO POLYMER BULLETIN
LA English
DT Article
ID NANOTUBE COMPOSITES; IONIZING-RADIATION; POLYMETHYLMETHACRYLATE;
METHACRYLATE); IRRADIATION; POLYMERS
AB Poly(methyl methacrylate) (PMMA) was produced via free radical polymerization. Polymer samples were sonicated and melt compounded to form 1%, 0.5%, and 0.25% PMMA/soot samples. Soot containing unpurified carbon nanotubes was provided by NASA Ames Research Center. The composites were compression molded and exposed to ionizing radiation in air from a Cesium-137 source. The PMMA/soot samples were characterized before and after exposure to radiation. Differential Scanning Calorimetry (DSC) was used to determine glass transition temperatures. Mechanical properties of composites were characterized via Dynamic Mechanical Analysis (DMA) and microhardness measurements. The glass transition temperatures from this study, when compared to similar studies conducted by Harmon et. al on purified single-wall and multi-wall carbon nanotube composites indicate that soot composites possess lower radiation resistance.
C1 Univ S Florida, Dept Chem, Tampa, FL 33620 USA.
NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA.
RP Harmon, JP (reprint author), Univ S Florida, Dept Chem, 4202 E Fowler Ave, Tampa, FL 33620 USA.
EM hannon@cas.usf.edu
NR 18
TC 14
Z9 14
U1 0
U2 8
PU SPRINGER
PI NEW YORK
PA 233 SPRING STREET, NEW YORK, NY 10013 USA
SN 0170-0839
J9 POLYM BULL
JI Polym. Bull.
PD OCT
PY 2004
VL 52
IS 3-4
BP 259
EP 266
DI 10.1007/s00289-004-0289-6
PG 8
WC Polymer Science
SC Polymer Science
GA 864DV
UT WOS:000224614700010
ER
PT J
AU Hall, RM
Woodson, SH
Chambers, JR
AF Hall, RM
Woodson, SH
Chambers, JR
TI Overview of the abrupt wing stall program
SO PROGRESS IN AEROSPACE SCIENCES
LA English
DT Review
AB The abrupt wing stall (AWS) program was a 5-year program that addressed the problem of uncommanded, transonic lateral motions, such as wing drop, with experimental, computational, and simulation tools. A brief background is presented as are the motivations and objectives for the AWS program. Since the wing drop discovered in preproduction flight testing for the F/A-18E/F program was the immediate impetus for the AMS project, and since extensive flight data had been gathered, the preproduction F/A-18E configuration was utilized to examine the ability of current computational and wind-tunnel tools to predict such phenomena prior to flight. The scope included both steady and unsteady flow field studies for transonic flight conditions. The AMS program also adapted and assessed a free-to-roll (FTR) wind-tunnel testing technique traditionally used for low-speed studies of lateral dynamic stability for the transonic flow regime. This transonic FTR capability was demonstrated first in a proof-of-concept study and then applied to an investigation of four different aircraft configurations-two that were susceptible to wing drop, the preproduction F/A-18E and the AV-8B, and two that were not, the F/A-18C and the F-16C. Design insights have also been obtained from computational studies of these four aircraft configurations and from computations quantifying the impact of the various geometric wing differences between the F/A-18C and the F/A-18E. Finally, guidance is provided for assessing, in the simulator, the relative impact of experimentally determined lateral aerodynamic data on flight characteristics before going to flight test. Published by Elsevier Ltd.
C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA.
Naval Air Syst Command, Patuxent River, MD 20670 USA.
Ball Aerosp Syst Div, Fairborn, OH 45324 USA.
RP Hall, RM (reprint author), NASA, Langley Res Ctr, Mail Stop 499, Hampton, VA 23681 USA.
EM robert.m.hall@nasa.gov
NR 34
TC 2
Z9 3
U1 2
U2 2
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0376-0421
J9 PROG AEROSP SCI
JI Prog. Aeosp. Sci.
PD OCT
PY 2004
VL 40
IS 7
BP 417
EP 452
DI 10.1016/j.paerosci.2004.10.002
PG 36
WC Engineering, Aerospace
SC Engineering
GA 900GS
UT WOS:000227204000001
ER
PT J
AU Lachter, J
Forster, KI
Ruthruff, E
AF Lachter, J
Forster, KI
Ruthruff, E
TI Forty-five years after Broadbent (1958): Still no identification without
attention
SO PSYCHOLOGICAL REVIEW
LA English
DT Article; Proceedings Paper
CT 43rd Annual Meeting of the Psychonomic-Society
CY NOV, 2002
CL KANSAS CITY, MO
SP Psychon Soc
ID VISUAL WORD RECOGNITION; FEATURE-INTEGRATION-THEORY; LATERAL GENICULATE
BODY; SHOCK-ASSOCIATED WORDS; SELECTIVE-ATTENTION; PERCEPTUAL LOAD;
SPATIAL ATTENTION; LEXICAL DECISION; CHRONOMETRIC EVIDENCE; EXTRASTRIATE
CORTEX
AB According to D. E. Broadbent's (1958) selective filter theory, people do not process unattended stimuli beyond the analysis of basic physical properties. This theory was later rejected on the basis of numerous findings that people identify irrelevant (and supposedly unattended) stimuli. A careful review of this evidence, however, reveals strong reasons to doubt that these irrelevant stimuli were in fact unattended. This review exposed a clear need for new experiments with tight control over the locus of attention. The authors present 5 such experiments using a priming paradigm. When steps were taken to ensure that irrelevant stimuli were not attended, these stimuli produced no priming effects. Hence, the authors found no evidence that unattended stimuli can be identified. The results support a modem version of Broadbent's selective theory, updated to reflect recent research advances.
C1 NASA, Ames Res Ctr, Human Factors Res & Technol Div, Moffett Field, CA 94035 USA.
Univ Arizona, Dept Psychol, Tucson, AZ 85721 USA.
RP Lachter, J (reprint author), NASA, Ames Res Ctr, Human Factors Res & Technol Div, MS 262-4, Moffett Field, CA 94035 USA.
EM jlachter@mail.arc.nasa.gov
NR 214
TC 171
Z9 176
U1 15
U2 65
PU AMER PSYCHOLOGICAL ASSOC
PI WASHINGTON
PA 750 FIRST ST NE, WASHINGTON, DC 20002-4242 USA
SN 0033-295X
EI 1939-1471
J9 PSYCHOL REV
JI Psychol. Rev.
PD OCT
PY 2004
VL 111
IS 4
BP 880
EP 913
DI 10.1037/0033-295x.111.4.880
PG 34
WC Psychology; Psychology, Multidisciplinary
SC Psychology
GA 859KC
UT WOS:000224261000003
PM 15482066
ER
PT J
AU Donnellan, A
Mora, P
Matsu'ura, M
Yin, XC
AF Donnellan, A
Mora, P
Matsu'ura, M
Yin, XC
TI Computational earthquake science - Part I
SO PURE AND APPLIED GEOPHYSICS
LA English
DT Editorial Material
DE earthquake physics; numerical modeling; finite element models; faults;
rheology; computational science
C1 CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA.
Univ Queensland, Dept Earth Sci, QUAKES, ESSCC, Brisbane, Qld 4072, Australia.
Univ Tokyo, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan.
Chinese Acad Sci, Inst Mech, Lab Nonlinear Mech, Beijing 100080, Peoples R China.
Chinese Acad Sci, CSB, Ctr Anal & Predict, Beijing 100080, Peoples R China.
RP Donnellan, A (reprint author), CALTECH, Jet Prop Lab, Div Earth & Space Sci, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM donnellan@jpl.nasa.gov; morap@quakes.uq.edu.an;
matsuura@eps.s.u-tokyo.ac.jp; xcyin@public.bta.net.cn
NR 0
TC 2
Z9 2
U1 0
U2 0
PU BIRKHAUSER VERLAG AG
PI BASEL
PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND
SN 0033-4553
J9 PURE APPL GEOPHYS
JI Pure Appl. Geophys.
PD OCT
PY 2004
VL 161
IS 9-10
BP 1823
EP 1825
DI 10.1007/s00024-004-2533-2
PG 3
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 852HG
UT WOS:000223745800001
ER
PT J
AU Dowling, JP
Franson, JD
Lee, H
Milburn, GJ
AF Dowling, J. P.
Franson, J. D.
Lee, H.
Milburn, G. J.
TI Towards Scalable Linear-Optical Quantum Computers
SO QUANTUM INFORMATION PROCESSING
LA English
DT Article
DE Linear optics; Logic gates; Single photon; Quantum memory; Quantum
repeater
AB Scalable quantum computation with linear optics was considered to be impossible due to the lack of efficient two-qubit logic gates, despite the ease of implementation of one-qubit gates. Two-qubit gates necessarily need a non-linear interaction between the two photons, and the efficiency of this non-linear interaction is typically very small in bulk materials. However, it has recently been shown that this barrier can be circumvented with effective non-linearities produced by projective measurements, and with this work linear-optical quantum computing becomes a new avenue towards scalable quantum computation. We review several issues concerning the principles and requirements of this scheme.
C1 [Dowling, J. P.; Lee, H.] CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, Sect 367, Pasadena, CA 91109 USA.
[Franson, J. D.] Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA.
[Milburn, G. J.] Univ Queensland, Ctr Quantum Comp Technol, Brisbane, Qld 4072, Australia.
[Dowling, J. P.] Louisiana State Univ, Dept Phys, Baton Rouge, LA 70803 USA.
RP Lee, H (reprint author), CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, Sect 367, MS 126-347,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
RI DOWLING, JONATHAN/L-2749-2013
FU National Security Agency; Advanced Research and Development Activity;
Defense Advanced Research Projects Agency; National Reconnaissance
Office; Office of Naval Research; Army Research Office; IRD funding;
NASA Intelligent Systems Program
FX Part of this work was carried out at the Jet Propulsion Laboratory,
California Institute of Technology, under a contract with the National
Aeronautics and Space Administration. Authors wish to acknowledge
support from the National Security Agency, the Advanced Research and
Development Activity, the Defense Advanced Research Projects Agency, the
National Reconnaissance Office, the Office of Naval Research, the Army
Research Office, the IR&D funding, and the NASA Intelligent Systems
Program.
NR 30
TC 7
Z9 8
U1 0
U2 4
PU SPRINGER
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 1570-0755
J9 QUANTUM INF PROCESS
JI Quantum Inf. Process.
PD OCT
PY 2004
VL 3
IS 1-5
BP 205
EP 213
DI 10.1007/s11128-004-9419-1
PG 9
WC Physics, Multidisciplinary; Physics, Mathematical
SC Physics
GA V25UO
UT WOS:000208503100013
ER
PT J
AU Tuck, AF
Hovde, SJ
Bui, TP
AF Tuck, AF
Hovde, SJ
Bui, TP
TI Scale invariance in jet streams: ER-2 data around the
lower-stratospheric polar night vortex
SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
LA English
DT Article
DE aircraft winds; multifractal
ID ANTARCTIC OZONE EXPERIMENT; HEMISPHERE LOWER STRATOSPHERE;
NITROUS-OXIDE; AIRCRAFT OBSERVATIONS; WINTER; DYNAMICS; MODEL; EDGE
AB High altitude ER-2 aircraft observations in both hemispheres of the lower-stratospheric polar night jet stream reveal generalized scale invariance. The scaling exponent has systematic correlation with wind shear and temperature gradient showing across-jet persistence, along-jet anti-persistence, and an overall average value approximate to5/9. The analysis provides a natural connection between generalized scale invariance and traditional large-scale dynamical meteorology. For one mission in the southern hemisphere composite variograms could be constructed for nitrous oxide and ozone, from which it was deduced that the former is a true passive scalar in the lower stratosphere, while sources and sinks are operative for the latter.
C1 NOAA, Aeron Lab, Boulder, CO 80305 USA.
Univ Colorado, CIRES, Boulder, CO 80309 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP NOAA, Aeron Lab, 325 Broadway, Boulder, CO 80305 USA.
EM adrian.f.tuck@noaa.gov
RI Tuck, Adrian/F-6024-2011
OI Tuck, Adrian/0000-0002-2074-0538
NR 47
TC 14
Z9 14
U1 0
U2 1
PU WILEY-BLACKWELL
PI HOBOKEN
PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA
SN 0035-9009
EI 1477-870X
J9 Q J ROY METEOR SOC
JI Q. J. R. Meteorol. Soc.
PD OCT
PY 2004
VL 130
IS 602
BP 2423
EP 2444
DI 10.1256/qj.03.191
PN A
PG 22
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 868UI
UT WOS:000224938100006
ER
PT J
AU Ma, J
Waugh, DW
Douglass, AR
Kawa, SR
Newman, PA
Pawson, S
Stolarski, R
Lin, SJ
AF Ma, J
Waugh, DW
Douglass, AR
Kawa, SR
Newman, PA
Pawson, S
Stolarski, R
Lin, SJ
TI Interannual variability of stratospheric trace gases: The role of
extratropical wave driving
SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
LA English
DT Article
DE ozone; polar vortex; stratospheric transport
ID MIDDLE ATMOSPHERE; OZONE; MODEL; GCM; CIRCULATION; SIMULATION;
TRANSPORT; MACCM2; FLUX; CCM2
AB The interannual variability of methane and ozone from a 35-year middle atmosphere climate model simulation with no interannual variations in external forcing or chemistry is examined. The internal dynamics in the model produces large tracer interannual variability, particularly in polar regions. During winter and spring the interannual standard deviation in the polar lower-middle stratosphere is about 30% of the climatological mean for methane and 15% for ozone. Global-scale, coherent interannual variations in temperature, residual circulation, and tracers are correlated with variability in the extratropical wave forcing. Statistically significant positive correlations between wave driving and polar tracer tendencies, including column ozone, occur from autumn to spring in both hemispheres. These positive correlations imply that interannual variations in polar tracers are dominated by variations in the horizontal eddy transport and not by variations in residual mean descent rates.
C1 Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
NOAA, GFDL, Princeton, NJ USA.
RP Waugh, DW (reprint author), Johns Hopkins Univ, Dept Earth & Planetary Sci, 3400 N Charles St, Baltimore, MD 21218 USA.
EM waugh@jhu.edu
RI Newman, Paul/D-6208-2012; Douglass, Anne/D-4655-2012; Kawa,
Stephan/E-9040-2012; Stolarski, Richard/B-8499-2013; Pawson,
Steven/I-1865-2014; Waugh, Darryn/K-3688-2016
OI Newman, Paul/0000-0003-1139-2508; Stolarski,
Richard/0000-0001-8722-4012; Pawson, Steven/0000-0003-0200-717X; Waugh,
Darryn/0000-0001-7692-2798
NR 31
TC 7
Z9 7
U1 0
U2 0
PU ROYAL METEOROLOGICAL SOC
PI READING
PA 104 OXFORD ROAD, READING RG1 7LJ, BERKS, ENGLAND
SN 0035-9009
J9 Q J ROY METEOR SOC
JI Q. J. R. Meteorol. Soc.
PD OCT
PY 2004
VL 130
IS 602
BP 2459
EP 2474
DI 10.1256/qj.04.28
PN A
PG 16
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 868UI
UT WOS:000224938100008
ER
PT J
AU Poli, P
Joiner, J
AF Poli, P
Joiner, J
TI Effects of horizontal gradients on GPS radio occultation observation
operators. I: Ray tracing
SO QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY
LA English
DT Article
DE bending angle; geometrical optics; refraction
ID LOWER TROPOSPHERE; BENDING ANGLE; ATMOSPHERE; ERRORS; ASSIMILATION;
VALIDATION; SIMULATION; SYSTEM; IMPACT; CHAMP
AB Global Positioning System (GPS) radio occultation (RO) bending angle and refractivity data provide information about the vertical structure of temperature and humidity in the earth's atmosphere. Assuming spherical symmetry in a GPS RO observation operator creates errors when calculating GPS RO observables from a background. These errors find their source in the presence of horizontal gradients of temperature and humidity. Tangent point drift (TPD) causes occulting rays to scan the atmosphere in various occultation planes. Horizontal gradients along the ray (HGR) cause the bending of each ray to be different from calculations that assume spherical symmetry.
Using simulations, we show that HGR-induced r.m.s. errors are larger than TPD-induced r.m.s. errors in the lower troposphere only. TPD-induced errors are more important in the stratosphere. We account for TPD and HGR using a multi-plane two-dimensional (2D) ray-tracing observation operator. We show that bending angle and refractivity can be calculated more accurately with this 2D operator than an operator that assumes spherical symmetry. We use 6335 CHAMP and SAC-C occultations as a validation. These occultations were processed by the Jet Propulsion Laboratory using geometrical optics and canonical transform methods. Our results indicate that analyses and 6-hour forecasts can provide sufficiently accurate horizontal gradient information to the 2D operator. We show that the effects due to HGR can be satisfactorily simulated using ray tracing in one plane only. The effects due to TPD can be accounted for by considering a slanted profile which follows the tangent point trajectory. These results have important implications for the development of fast observation operators for data assimilation in numerical weather prediction.
C1 Meteo France, CNRM, GMAP, F-31057 Toulouse 01, France.
Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA.
NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
RP Poli, P (reprint author), Meteo France, CNRM, GMAP, 42 Av Coriolis, F-31057 Toulouse 01, France.
EM paul.poli@meteo.fr
RI Joiner, Joanna/D-6264-2012;
OI Poli, Paul/0000-0002-8392-6524
NR 26
TC 20
Z9 21
U1 0
U2 3
PU ROYAL METEOROLOGICAL SOC
PI READING
PA 104 OXFORD ROAD, READING RG1 7LJ, BERKS, ENGLAND
SN 0035-9009
J9 Q J ROY METEOR SOC
JI Q. J. R. Meteorol. Soc.
PD OCT
PY 2004
VL 130
IS 603
BP 2787
EP 2805
DI 10.1256/qj.03.228
PN B
PG 19
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 884JV
UT WOS:000226081900006
ER
PT J
AU Gaskin, JA
Sharma, D
Ramsey, B
Seller, P
AF Gaskin, JA
Sharma, D
Ramsey, B
Seller, P
TI Evaluation of a cadmium-zinc-telluride focal plane detector for hard
X-ray astronomy
SO RADIATION PHYSICS AND CHEMISTRY
LA English
DT Article; Proceedings Paper
CT 9th International Symposium on Radiation Physics
CY OCT 26-31, 2003
CL Cape Town, SOUTH AFRICA
C1 UAH, Phys Dept OB 330, Huntsville, AL 35899 USA.
NASA, MSFC, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA.
Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England.
RP Gaskin, JA (reprint author), UAH, Phys Dept OB 330, Huntsville, AL 35899 USA.
EM gaskinj@email.uah.edu
NR 8
TC 1
Z9 1
U1 1
U2 1
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0969-806X
J9 RADIAT PHYS CHEM
JI Radiat. Phys. Chem.
PD OCT-NOV
PY 2004
VL 71
IS 3-4
BP 731
EP 732
DI 10.1016/j.radphyschem.2004.04.081
PG 2
WC Chemistry, Physical; Nuclear Science & Technology; Physics, Atomic,
Molecular & Chemical
SC Chemistry; Nuclear Science & Technology; Physics
GA 856CB
UT WOS:000224020100032
ER
PT J
AU Frigo, SP
McNulty, I
Richmond, RC
Ehret, CF
AF Frigo, SP
McNulty, I
Richmond, RC
Ehret, CF
TI Photoabsorption study of Bacillus megaterium, DNA and related biological
materials in the phosphorus K-shell edge region
SO RADIATION RESEARCH
LA English
DT Article
ID X-RAY-ABSORPTION; SYNCHROTRON-RADIATION; SPORES; CELLS; DIFFRACTION;
SPECTRA
AB We measured the X-ray transmission spectra of several biologically related samples in the phosphorus K-shell edge absorption region. These include red phosphorus, hydrated sodium phosphate (Na(3)PO(4)(.)12 H2O), deoxyribonucleic acid (DNA), adenosine triphosphate (ATP), diolylphosphatidyl choline (DOPC), and Bacillus megaterium spores. Red phosphorus essentially displays an edge-jump. All other spectra are similar in form and energy position: Each is dominated by a narrower, more intense first peak and a broader but less intense second peak. The corresponding K-shell edge absorption thresholds are shifted toward higher energy relative to that for red phosphorus, as expected for increasing degrees of phosphorus oxidation. The B. megaterium spectrum has aspects common to both the phosphate and DNA spectra and is therefore interpreted as a composite of spectra arising from DNA, ribonucleic acid (RNA) and phosphates within the spore. The B. megaterium spore spectrum provides information for resonant radiation damage studies in the phosphorus K-shell edge absorption region by identifying candidate photoexcitations. In addition, the absorption spectra will be useful in X-ray microscopy and macromolecular crystallography studies at the phosphorus K-shell edge. (C) 2004 by Radiation Research Society.
C1 No Arizona Univ, Dept Phys & Astron, Flagstaff, AZ 86011 USA.
Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA.
NASA, Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
Gen Chronobion, Clarendon Hills, IL 60514 USA.
RP Frigo, SP (reprint author), No Arizona Univ, Dept Phys & Astron, POB 6010, Flagstaff, AZ 86011 USA.
EM sean.frigo@nau.edu
NR 23
TC 0
Z9 0
U1 1
U2 2
PU RADIATION RESEARCH SOC
PI OAK BROOK
PA 820 JORIE BOULEVARD, OAK BROOK, IL 60523 USA
SN 0033-7587
J9 RADIAT RES
JI Radiat. Res.
PD OCT
PY 2004
VL 162
IS 4
BP 464
EP 468
DI 10.1667/RR3132
PG 5
WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging
SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology,
Nuclear Medicine & Medical Imaging
GA 892IF
UT WOS:000226643100015
PM 15447035
ER
PT J
AU Shlyaptseva, A
Fedin, D
Hamasha, S
Harris, C
Kantsyrev, V
Neill, P
Ouart, N
Safronova, UI
Beiersdorfer, P
Boyce, K
Brown, GV
Kelley, R
Kilbourne, CA
Porter, FS
AF Shlyaptseva, A
Fedin, D
Hamasha, S
Harris, C
Kantsyrev, V
Neill, P
Ouart, N
Safronova, UI
Beiersdorfer, P
Boyce, K
Brown, GV
Kelley, R
Kilbourne, CA
Porter, FS
TI Development of M-shell x-ray spectroscopy and spectropolarimetry of
z-pinch tungsten plasmas
SO REVIEW OF SCIENTIFIC INSTRUMENTS
LA English
DT Article; Proceedings Paper
CT 15th Topical Conference on High-Temperature Plasma Diagnostics
CY APR 19-22, 2004
CL San Diego, CA
SP Amer Phys Soc, US DOE, Gen Atom
ID ELECTRON-BEAM; IONS
AB The development of spectroscopic modeling of M-shell tungsten z-pinch plasma is presented. The spectral region from 3.5 to 6.5 Angstrom includes three distinct groups of transitions, and the best candidates for M-shell diagnostics are identified. Theoretical modeling is benchmarked with LLNL electron beam ion trap data produced at different energies of the electron beam and recorded by crystal spectrometers and a broadband microcalorimeter. A new high temperature plasma diagnostic tool, x-ray spectropolarimetry, is proposed to study polarization of W line emission and is illustrated using the results of x-pinch polarization-sensitive experiments. The x-ray line polarization of the prominent M-shell tungsten lines is calculated, and polarization markers are identified. The advantage of using x-pinch W wire experiments for the development of M-shell diagnostics is shown. (C) 2004 American Institute of Physics.
C1 Univ Nevada, Reno, NV 89557 USA.
Lawrence Livermore Natl Lab, Livermore, CA 94551 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA.
RP Shlyaptseva, A (reprint author), Univ Nevada, Reno, NV 89557 USA.
RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012
OI Porter, Frederick/0000-0002-6374-1119;
NR 8
TC 12
Z9 12
U1 0
U2 2
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0034-6748
J9 REV SCI INSTRUM
JI Rev. Sci. Instrum.
PD OCT
PY 2004
VL 75
IS 10
BP 3750
EP 3752
DI 10.1063/1.1781757
PN 2
PG 3
WC Instruments & Instrumentation; Physics, Applied
SC Instruments & Instrumentation; Physics
GA 866EF
UT WOS:000224755900111
ER
PT J
AU Porter, FS
Brown, GV
Boyce, KR
Kelley, RL
Kilbourne, CA
Beiersdorfer, P
Chen, H
Terracol, S
Kahn, SM
Szymkowiak, AE
AF Porter, FS
Brown, GV
Boyce, KR
Kelley, RL
Kilbourne, CA
Beiersdorfer, P
Chen, H
Terracol, S
Kahn, SM
Szymkowiak, AE
TI The Astro-E2 X-ray spectrometer/EBIT microcalorimeter x-ray spectrometer
SO REVIEW OF SCIENTIFIC INSTRUMENTS
LA English
DT Article; Proceedings Paper
CT 15th Topical Conference on High-Temperature Plasma Diagnostics
CY APR 19-22, 2004
CL San Diego, CA
SP Amer Phys Soc, US DOE, Gen Atom
ID ASTROPHYSICS; EMISSION
AB The x-ray spectrometer (XRS) instrument is a revolutionary nondispersive spectrometer that will form the basis for the Astro-E2 observatory to be launched in 2005. We have recently installed a flight spare XRS microcalorimeter spectrometer at the EBIT-I and SuperEBIT facility at LLNL replacing the XRS from the earlier Astro-E mission and providing twice the resolving power. The XRS microcalorimeter is an x-ray detector that senses the heat deposited by the incident photon. It achieves a high energy resolution by operating at 0.06 K and by carefully engineering the heat capacity and thermal conductance. The XRS/EBIT instrument has 32 pixels in a square geometry and achieves an energy resolution of 6 eV at 6 keV, with a bandpass from 0.1 to 12 keV (or more at higher operating temperature). The instrument allows detailed studies of the x-ray line emission of laboratory plasmas. The XRS/EBIT also provides an extensive calibration "library" for the Astro-E2 observatory. (C) 2004 American Institute of Physics.
C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Lawrence Livermore Natl Lab, Livermore, CA 94550 USA.
Stanford Univ, Stanford, CA 94305 USA.
Yale Univ, New Haven, CT 06520 USA.
RP Porter, FS (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RI Porter, Frederick/D-3501-2012; Kelley, Richard/K-4474-2012; XRAY,
SUZAKU/A-1808-2009
OI Porter, Frederick/0000-0002-6374-1119;
NR 11
TC 54
Z9 54
U1 0
U2 3
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0034-6748
J9 REV SCI INSTRUM
JI Rev. Sci. Instrum.
PD OCT
PY 2004
VL 75
IS 10
BP 3772
EP 3774
DI 10.1063/1.1781758
PN 2
PG 3
WC Instruments & Instrumentation; Physics, Applied
SC Instruments & Instrumentation; Physics
GA 866EF
UT WOS:000224755900118
ER
PT J
AU Hathaway, DH
Wilson, RM
AF Hathaway, DH
Wilson, RM
TI What the sunspot record tells us about space climate
SO SOLAR PHYSICS
LA English
DT Article; Proceedings Paper
CT 1st International Symposium on Space Climate
CY JUN 20-23, 2004
CL Oulu, FINLAND
ID SOLAR-ACTIVITY RECONSTRUCTION; DEEP MERIDIONAL FLOW; ACTIVE LONGITUDES;
DAY PERIODICITY; MAGNETIC-FIELD; DIFFERENTIAL ROTATION; SOUTH ASYMMETRY;
CYCLE PERIOD; NUMBERS; LOST
AB The records concerning the number, sizes, and positions of sunspots provide a direct means of characterizing solar activity over nearly 400 years. Sunspot numbers are strongly correlated with modern measures of solar activity including: 10.7-cm radio flux, total irradiance, X-ray flares, sunspot area, the baseline level of geomagnetic activity, and the flux of galactic cosmic rays. The Group Sunspot Number provides information on 27 sunspot cycles, far more than any of the modern measures of solar activity, and enough to provide important details about long-term variations in solar activity or "Space Climate." The sunspot record shows: 1) sunspot cycles have periods of 131 +/- 14 months with a normal distribution; 2) sunspot cycles are asymmetric with a fast rise and slow decline; 3) the rise time from minimum to maximum decreases with cycle amplitude; 4) large amplitude cycles are preceded by short period cycles; 5) large amplitude cycles are preceded by high minima; 6) although the two hemispheres remain linked in phase, there are significant asymmetries in the activity in each hemisphere; 7) the rate at which the active latitudes drift toward the equator is anti-correlated with the cycle period; 8) the rate at which the active latitudes drift toward the equator is positively correlated with the amplitude of the cycle after the next; 9) there has been a significant secular increase in the amplitudes of the sunspot cycles since the end of the Maunder Minimum (1715); and 10) there is weak evidence for a quasi-periodic variation in the sunspot cycle amplitudes with a period of about 90 years. These characteristics indicate that the next solar cycle should have a maximum smoothed sunspot number of about 145 +/- 30 in 2010 while the following cycle should have a maximum of about 70 +/- 30 in 2023.
C1 NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35812 USA.
RP Hathaway, DH (reprint author), NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35812 USA.
EM david.hathaway@msfc.nasa.gov
NR 61
TC 74
Z9 77
U1 0
U2 3
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0038-0938
J9 SOL PHYS
JI Sol. Phys.
PD OCT
PY 2004
VL 224
IS 1
BP 5
EP 19
DI 10.1007/s11207-005-3996-8
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 922PF
UT WOS:000228849200002
ER
PT J
AU Sotiriou-Leventis, C
Yang, JH
Duan, PG
Leventis, N
AF Sotiriou-Leventis, C
Yang, JH
Duan, PG
Leventis, N
TI Ru(II) tris(3,8-dibromo-1,10-phenanthroline) - A new versatile core for
the divergent synthesis of hyperbranched systems
SO SYNTHETIC COMMUNICATIONS
LA English
DT Article
DE ruthenium; tris(3,8-dibromo-1,10-phenanthroline); divergent;
hyperbranched
ID POLYPYRIDINE COMPLEXES; DENDRIMERS; 3,8-DIBROMO-1,10-PHENANTHROLINE;
1,10-PHENANTHROLINE; LUMINESCENCE; CONVERGENT
AB We report the first synthesis of Ru(II) tris(3,8-dibromo-1,10-phenanthroline) bishexafluorophosphate (1), and we demonstrate its utility as a building core for the divergent synthesis of hyperbranched systems by coupling with phenylacetylene in the preparation of Ru(II) tris(3,8-diphenylethynyl-1,10-phenanthroline) dihexafluorophosphate (2).
C1 Univ Missouri, Dept Chem, Rolla, MO 65409 USA.
NASA, Glenn Res Ctr, Div Mat, Polymers Branch, Cleveland, OH USA.
RP Sotiriou-Leventis, C (reprint author), Univ Missouri, Dept Chem, Rolla, MO 65409 USA.
EM nicholas.leventis@nasa.gov
NR 23
TC 1
Z9 1
U1 1
U2 4
PU MARCEL DEKKER INC
PI NEW YORK
PA 270 MADISON AVE, NEW YORK, NY 10016 USA
SN 0039-7911
J9 SYNTHETIC COMMUN
JI Synth. Commun.
PD OCT
PY 2004
VL 34
IS 19
BP 3491
EP 3496
DI 10.1081/SCC-200030975
PG 6
WC Chemistry, Organic
SC Chemistry
GA 861ME
UT WOS:000224419900006
ER
PT J
AU Echer, E
Guarnieri, FL
Rigozo, NR
Vieira, LEA
AF Echer, E
Guarnieri, FL
Rigozo, NR
Vieira, LEA
TI A study of the latitudinal dependence of the quasi-biennial oscillation
in Total Ozone Mapping Spectrometer total ozone
SO TELLUS SERIES A-DYNAMIC METEOROLOGY AND OCEANOGRAPHY
LA English
DT Article
ID TOMS; STRATOSPHERE; MODEL; CYCLE
AB A wavelet multiresolution analysis of the quasi-biennial oscillation (QBO) latitudinal structure in total ozone is performed for the period 1979-1992 (Nimbus-7 TOMS data). It has been found that ozone is nearly in phase with the QBO signal in the equatorial region (0degrees-5degrees and 5degrees-10degrees), and it is out of phase (lag similar to +15 and -15 months in north and south) in the 10degrees-15degrees to 55degrees-60degrees latitudinal bands. The cross-correlation coefficient between total ozone and zonal wind index is high (>0.7) at latitudes lower than 10degrees, decreases in the transition region 10degrees-15degrees (r similar to 0.4) and it has a non-linear profile at high latitudes, with a maximum near the 25degrees-30degrees band. The correlation is observed to be higher in the Southern Hemisphere latitudinal bands. Spectral analysis was performed for each latitudinal range, and QBO period and amplitude profiles were obtained. A detailed latitudinal profile of the QBO signal in total ozone is obtained from the present analysis.
C1 Inst Nacl Pesquisas Espaciais, BR-12201970 Sao Jose Dos Campos, SP, Brazil.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
FAETEC, Fac Tecnol Thereza Porto Marques, Jacarei, SP, Brazil.
RP Echer, E (reprint author), Inst Nacl Pesquisas Espaciais, Av Astronautas 1758, BR-12201970 Sao Jose Dos Campos, SP, Brazil.
EM eecher@dge.inpe.br
RI Vieira, Luis Eduardo/A-5548-2008; Rigozo, Nivaor/A-6650-2013
OI Vieira, Luis Eduardo/0000-0002-9376-475X;
NR 27
TC 13
Z9 14
U1 0
U2 0
PU BLACKWELL MUNKSGAARD
PI COPENHAGEN
PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK
SN 0280-6495
J9 TELLUS A
JI Tellus Ser. A-Dyn. Meteorol. Oceanol.
PD OCT
PY 2004
VL 56
IS 5
BP 527
EP 535
DI 10.1111/j.1600-0870.2004.00080.x
PG 9
WC Meteorology & Atmospheric Sciences; Oceanography
SC Meteorology & Atmospheric Sciences; Oceanography
GA 869CT
UT WOS:000224961700010
ER
PT J
AU Rubincam, DP
AF Rubincam, DP
TI Black body temperature, orbital elements, the Milankovitch precession
index, and the Seversmith psychroterms
SO THEORETICAL AND APPLIED CLIMATOLOGY
LA English
DT Article
ID GLACIAL CYCLES; CLIMATE SWITCH; ICE AGES; SEA-ICE; EARTH; INSOLATION
AB The temperature T of a black or gray body orbiting the Sun can be expressed in terms of spherical harmonics in latitude and longitude, its Keplerian orbital elements, and a variable describing rotation about its axis. Assuming that the Earth is a black or gray body without thermal inertia, the resulting equation for T exhibits previously unrecognized odd-degree zonal terms dubbed "Seversmith psychroterms.'' They cause a hemispheric temperature difference which depends upon e sin omega(S), where e is the orbital eccentricity and omega(S) is the Sun's argument of perigee measured in an Earth-centered frame. The hemisphere containing perihelion is the cooler. For a gray body with the Earth's average albedo of 0.3, an emissivity of unity, and an obliquity of 23.5degrees, the pole-to-pole temperature difference for the combined first and third degree spherical harmonic psychroterms can reach 3.4 K for the present eccentricity of 0.016, and 12.9 K for the maximum eccentricity of 0.06. While a thermally inertia-less black or gray body with boiling hot subsolar points and nights at absolute zero are poor models for the Earth, the Seversmith psychroterms will survive in more realistic models ( although with smaller amplitudes) because the Earth radiates nonlinearly in T. The psychroterms acts in the direction opposite to the Milankovitch precession index, which also depends on e sin omega(S): by warming the cool northern summers, the psychroterms make it harder for the traditional Milankovitch mechanism to operate. The Seversmith psychroterms could in fact be responsible for the ice sheets that cycle with e sin omega(S), instead of the Milankovitch mechanism. By cooling the southern hemisphere for thousands of years when perihelion is in the south, the psychroterms may somehow cause the southern hemisphere to control the northern ice sheets associated with the 23 kyr and 19 kyr periods ( kyr = 10(3) years), possibly through ice-albedo feedback in the sea ice surrounding Antarctica. Two other unexpected features besides the psychroterms are: while the average insolation increases with increasing e, the average temperature of the Earth paradoxically decreases; and the equator-to-pole temperature difference of 21 K on a gray body with an albedo equal to 0.3 and an emissivity of unity is actually smaller than the observed difference of 28 K on the real Earth.
C1 NASA, Goddard Space Flight Ctr, Terr Phys Lab, Geodynam Branch, Greenbelt, MD 20771 USA.
RP Rubincam, DP (reprint author), NASA, Goddard Space Flight Ctr, Terr Phys Lab, Geodynam Branch, Code 921,Bldg 33,Room G308, Greenbelt, MD 20771 USA.
EM david.p.rubincam@nasa.gov
RI Rubincam, David/D-2918-2012
NR 40
TC 10
Z9 11
U1 0
U2 2
PU SPRINGER WIEN
PI VIENNA
PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA
SN 0177-798X
J9 THEOR APPL CLIMATOL
JI Theor. Appl. Climatol.
PD OCT
PY 2004
VL 79
IS 1-2
BP 111
EP 131
DI 10.1007/s00704-004-0056-5
PG 21
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 864DY
UT WOS:000224615100011
ER
PT J
AU Miyoshi, K
Sutter, JK
Horan, RA
Naik, SK
Cupp, RJ
AF Miyoshi, K
Sutter, JK
Horan, RA
Naik, SK
Cupp, RJ
TI Assessment of erosion resistance of coated polymer matrix composites for
propulsion applications
SO TRIBOLOGY LETTERS
LA English
DT Article
DE polymer matrix composites; erosion-resistant coatings; optical
interferometry; inlet guide vane
AB The erosion behavior of tungsten carbide - cobalt ( WC - Co) coated and uncoated polymer matrix composites (PMCs) was examined with solid particle impingement using air jets. Erosion tests were conducted with Arizona Road Dust impinging at 20degrees, 60degrees, and 90degrees angles at a velocity of 229 m s(-1) at both 294 and 366 K. Noncontact optical profilometry was used to measure the wear volume loss. Results indicate that the WC - Co coating enhanced erosion resistance and reduced erosion wear volume loss by a factor of nearly 2. This should contribute to longer wear lives, reduced related breakdowns, decreased maintenance costs, and increased product reliability.
C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
Allison Adv Dev Co Rolls Royce Corp, Indianapolis, IN 46206 USA.
RP Miyoshi, K (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
EM Kazuhisa.Miyoshi-1@nasa.gov
NR 11
TC 7
Z9 7
U1 1
U2 6
PU KLUWER ACADEMIC/PLENUM PUBL
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 1023-8883
J9 TRIBOL LETT
JI Tribol. Lett.
PD OCT
PY 2004
VL 17
IS 3
BP 377
EP 387
DI 10.1023/B:TRIL.0000044486.14657.ea
PG 11
WC Engineering, Chemical; Engineering, Mechanical
SC Engineering
GA 861OX
UT WOS:000224427800005
ER
PT J
AU DellaCorte, C
AF DellaCorte, C
TI Gardosian patterns in tribology
SO TRIBOLOGY LETTERS
LA English
DT Article
DE tribology; friction; wear; ball bearing; ceramics; diamond; modeling
AB The following paper is a memorial retrospective on selected research of Dr. Michael N. Gardos. Dr. Gardos spent his professional career engaged in tribological research which often extended the scientific boundaries of the field. Several of the concepts he put forth into the tribology community were initially met with grave skepticism but over time his views have been largely embraced but not widely acknowledged. His approach to new research topics was often characterized by these qualities: ( 1) pioneering points of view, ( 2) the use of the model experiment, and ( 3) the presence of multiple research agendas for each single experiment. I have chosen to name his research approach as "Gardosian Patterns'' in honor of his contributions to Tribology. Three specific examples of these patterns will be reviewed. One is the concept of atomic level tailoring of materials to control macroscopic properties. A second is the use of a model ball polishing experiment to identify high fracture toughness ceramics for use in rolling element bearings. A third Gardosian Pattern example is his pioneering work with the tribology of diamond and diamond films in which he proposed controlling friction via surface bond tailoring. In these examples, Gardos utilized conventional research tools in unconventional ways and, at times, even developed new tools which have become part of the mainstream. His remarkable career has left a positive and lasting mark on Tribology.
C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP DellaCorte, C (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
EM christopher.dellacorte@nasa.gov
NR 12
TC 1
Z9 1
U1 0
U2 0
PU KLUWER ACADEMIC/PLENUM PUBL
PI NEW YORK
PA 233 SPRING ST, NEW YORK, NY 10013 USA
SN 1023-8883
J9 TRIBOL LETT
JI Tribol. Lett.
PD OCT
PY 2004
VL 17
IS 3
BP 463
EP 468
DI 10.1023/B:TRIL.0000044494.89244.d7
PG 6
WC Engineering, Chemical; Engineering, Mechanical
SC Engineering
GA 861OX
UT WOS:000224427800014
ER
PT J
AU DellaCorte, C
AF DellaCorte, C
TI Speak up! You have a voice, too
SO TRIBOLOGY & LUBRICATION TECHNOLOGY
LA English
DT Editorial Material
C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP DellaCorte, C (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
EM cdellacorte@stle.org
NR 0
TC 0
Z9 0
U1 0
U2 0
PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS
PI PARK RIDGE
PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA
SN 0024-7154
J9 TRIBOL LUBR TECHNOL
JI Tribol. Lubr. Technol.
PD OCT
PY 2004
VL 60
IS 10
BP 6
EP 6
PN 1
PG 1
WC Engineering, Mechanical
SC Engineering
GA 857XR
UT WOS:000224153700002
ER
PT J
AU Dykas, B
Howard, SA
AF Dykas, B
Howard, SA
TI Journal design considerations for turbomachine shafts supported on foil
air bearings
SO TRIBOLOGY TRANSACTIONS
LA English
DT Article; Proceedings Paper
CT 59th Annual Meeting of the
Society-of-Tribologists-and-Lubrication-Engineers
CY MAY 17-20, 2004
CL Toronto, CANADA
SP Soc Tribologists & Lubricat Engineers
DE foil bearing; journal; thermal effects
ID OIL-FREE TURBOMACHINERY; PERFORMANCE
AB Foil air bearings can offer substantial improvements over traditional rolling element bearings in many applications and are attractive as a replacement to enable the development of advanced oil-free turbomachinery. In the course of rigorous testing of foil journal bearings at NASA Glenn Research Center, shaft failure was repeatedly encountered at high ambient temperature and rotational speed, with moderate radial load. The cause of failure is determined to be excessive non-uniform shaft growth, which increases localized viscous heating in the gas film and eventually leads to a high-speed rub and destruction of the bearing and journal. Centrifugal loading of imbalance correction weights and axial temperature gradients within the journal due to the hydrodynamic nature of the foil bearings, determined by experiment and finite element analysis, are shown to be responsible for the non-uniform growth. Qualitative journal design guidance is given to aid in failure prevention.
C1 Case Western Reserve Univ, Cleveland, OH 44106 USA.
NASA, Glenn Res Ctr, Cleveland, OH USA.
RP Dykas, B (reprint author), Case Western Reserve Univ, Cleveland, OH 44106 USA.
NR 17
TC 37
Z9 37
U1 0
U2 5
PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS
PI PARK RIDGE
PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA
SN 1040-2004
J9 TRIBOL T
JI Tribol. Trans.
PD OCT-DEC
PY 2004
VL 47
IS 4
BP 508
EP 516
DI 10.1080/056981904990493391
PG 9
WC Engineering, Mechanical
SC Engineering
GA 867TO
UT WOS:000224865500006
ER
PT J
AU Bolton, SJ
Hansen, CJ
Matson, DL
Spilker, LJ
Lebreton, JP
AF Bolton, SJ
Hansen, CJ
Matson, DL
Spilker, LJ
Lebreton, JP
TI Cassini/Huygens flyby of the Jovian system
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
DE Cassini; Jupiter; Cassini-Huygens; flyby
ID JUPITER
AB This is an introduction to the series of 15 papers that follow. These report scientific results from the fields-and-particles instruments on Cassini/Huygens. For these works, their data acquisition started as early as 16 months before the passage by Jupiter and, for some, continued up to the approach to Saturn. The flyby of Jupiter provided a gravitational assist, which was necessary for the spacecraft to reach its destination, the Saturnian system. In addition to the scientific results, the Cassini/Huygens team gained much because Jupiter provided a dress rehearsal for skills needed at Saturn. The flyby also fostered international cooperation between the Cassini/Huygens teams, the Galileo teams, and the scientific teams using instruments in orbit about the Earth and on the ground. A number of important discoveries and insights came from these cooperative efforts. The boundary physics and compression of the Jovian magnetosphere was observed by both fields and particle instruments. The propagation of the solar wind between Earth and Jupiter was studied. The source of Jovian radio emission was further characterized. The first images of energetic neutral atoms at Jupiter were obtained.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
European Space Agcy, European Space Res & Technol Ctr, Dept Space Sci, NL-2200 AG Noordwijk, Netherlands.
RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM scott.j.bolton@jpl.nasa.gov
NR 23
TC 1
Z9 1
U1 0
U2 0
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9380
EI 2169-9402
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD SEP 30
PY 2004
VL 109
IS A9
AR A09S01
DI 10.1029/2004JA010742
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 861IT
UT WOS:000224410500008
ER
PT J
AU Richardson, IG
Cane, HV
AF Richardson, IG
Cane, HV
TI Identification of interplanetary coronal mass ejections at 1 AU using
multiple solar wind plasma composition anomalies
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
DE composition; interplanetary coronal mass ejections; solar wind
ID INTER-PLANETARY SHOCK; IONIZATION STATE; CHARGE STATES;
ELECTRON-TEMPERATURE; ABUNDANCE VARIATIONS; HELIUM ABUNDANCE; MAGNETIC
CLOUD; HEAVY-IONS; SPEED; ACCELERATION
AB We investigate the use of multiple simultaneous solar wind plasma compositional anomalies, relative to the composition of the ambient solar wind, for identifying interplanetary coronal mass ejection (ICME) plasma. We first summarize the characteristics of several solar wind plasma composition signatures (O(7)/O(6), Mg/O, Ne/O, Fe charge states, He/p) observed by the ACE and Wind spacecraft within the ICMEs during 1996-2002 identified by Cane and Richardson [2003], hereafter CR03. We then develop a set of simple criteria that may be used to identify such compositional anomalies and hence potential ICMEs. To distinguish these anomalies from the normal variations seen in ambient solar wind composition, which depend on the wind speed, we compare observed compositional signatures with those "expected'' in ambient solar wind with the same solar wind speed. This method identifies anomalies more effectively than the use of fixed thresholds. The occurrence rates of individual composition anomalies within ICMEs range from similar to70% for enhanced iron and oxygen charge states to similar to30% for enhanced He/p (>0.06) and Ne/O and are generally higher in magnetic clouds than other ICMEs. Intervals of multiple anomalies are usually associated with ICMEs and provide a basis for the identification of the majority of ICMEs. We estimate that CR03, who did not refer to composition data, probably identified similar to90% of the ICMEs present. However, around 10% of their ICMEs have weak compositional anomalies, suggesting that the presence of such signatures does not provide a necessary requirement for an ICME. We note a remarkably similar correlation between the Mg/O and O(7)/O(6) ratios in hourly-averaged data within both ICMEs and the ambient solar wind. This "universal'' relationship suggests that similar processes produce the first-ionization potential bias and enhanced ion freezing-in temperatures in the source regions of both ICMEs and the ambient solar wind.
C1 NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
Univ Tasmania, Sch Math & Phys, Hobart, Tas, Australia.
RP Richardson, IG (reprint author), NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA.
EM richardson@lheavx.gsfc.nasa.gov; hilary.cane@utas.edu.au
OI Richardson, Ian/0000-0002-3855-3634
NR 55
TC 83
Z9 87
U1 1
U2 6
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD SEP 30
PY 2004
VL 109
IS A9
AR A09104
DI 10.1029/2004JA010598
PG 17
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 861IT
UT WOS:000224410500006
ER
PT J
AU Njoku, EG
Lakshmi, V
O'Neill, PE
AF Njoku, EG
Lakshmi, V
O'Neill, PE
TI Soil moisture field experiment special issue
SO REMOTE SENSING OF ENVIRONMENT
LA English
DT Editorial Material
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Med Univ S Carolina, Dept Geol Sci, Charleston, SC 29425 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Njoku, EG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM eni.g.njoku@jpl.nasa.gov
RI O'Neill, Peggy/D-2904-2013; Lakshmi, Venkat/I-3078-2016
OI Lakshmi, Venkat/0000-0001-7431-9004
NR 0
TC 6
Z9 6
U1 0
U2 0
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0034-4257
J9 REMOTE SENS ENVIRON
JI Remote Sens. Environ.
PD SEP 30
PY 2004
VL 92
IS 4
BP 425
EP 426
DI 10.1016/j.rse.2004.06.001
PG 2
WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic
Technology
SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science &
Photographic Technology
GA 859UU
UT WOS:000224294200001
ER
PT J
AU Limaye, AS
Crosson, WL
Laymon, CA
Njoku, EG
AF Limaye, AS
Crosson, WL
Laymon, CA
Njoku, EG
TI Land cover-based optimal deconvolution of PALS L-band microwave
brightness temperatures
SO REMOTE SENSING OF ENVIRONMENT
LA English
DT Article; Proceedings Paper
CT Soil Moisture Experiment Conferernce (SMEX 02)
CY JAN, 2003
CL Columbia, MD
DE optimal deconvolution; microwave brightness temperature; sensor response
function; interpolation; PALS
ID SOIL-MOISTURE MEASUREMENTS; S-BAND
AB An optimal deconvolution (ODC) technique has been developed to estimate microwave brightness temperatures of agricultural fields using microwave radiometer observations. The technique is applied to airborne measurements taken by the Passive and Active L and S band (PALS) sensor in Iowa during Soil Moisture Experiments in 2002 (SMEX02). Agricultural fields in the study area were predominantly soybeans and corn. The brightness temperatures of corn and soybeans were observed to be significantly different because of large differences in vegetation biomass. PALS observations have significant over-sampling; observations were made about 100 in apart and the sensor footprint extends to about 400 in. Conventionally, observations of this type are averaged to produce smooth spatial data fields of brightness temperatures. However, the conventional approach is in contrast to reality in which the brightness temperatures are in fact strongly dependent on land cover, which is characterized by sharp boundaries. In this study, we mathematically deconvolve the observations into brightness temperature at the field scale (500-800 in) using the sensor antenna response function. The result is more accurate spatial representation of field-scale brightness temperatures, which may in turn lead to more accurate soil moisture retrieval. (C) 2004 Elsevier Inc. All rights reserved.
C1 Univ Alabama, Space Res Assoc, NSSTC, Global Hydrol & Climate Ctr, Huntsville, AL 35805 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Limaye, AS (reprint author), Univ Alabama, Space Res Assoc, NSSTC, Global Hydrol & Climate Ctr, 320 Sparkman Dr, Huntsville, AL 35805 USA.
EM Ashutosh.Limaye@msfc.nasa.gov
NR 16
TC 10
Z9 10
U1 0
U2 0
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0034-4257
J9 REMOTE SENS ENVIRON
JI Remote Sens. Environ.
PD SEP 30
PY 2004
VL 92
IS 4
BP 497
EP 506
DI 10.1016/j.rse.2004.02.019
PG 10
WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic
Technology
SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science &
Photographic Technology
GA 859UU
UT WOS:000224294200008
ER
PT J
AU Masters, D
Axelrad, P
Katzberg, S
AF Masters, D
Axelrad, P
Katzberg, S
TI Initial results of land-reflected GPS bistatic radar measurements in
SMEX02
SO REMOTE SENSING OF ENVIRONMENT
LA English
DT Article; Proceedings Paper
CT Soil Moisture Experiment Conferernce (SMEX 02)
CY JAN, 2003
CL Columbia, MD
DE Global Positioning System; SMEX02; soil moisture; bistatic radar
ID REMOTE-SENSING APPLICATIONS; SOIL-MOISTURE RETRIEVAL; MICROWAVE
RADIOMETER; MULTISTATIC RADAR; OCEAN SURFACE; WIND-SPEED; SIGNALS;
SCATTERING
AB To investigate scattering of Global Positioning System (GPS) signals from terrain and the potential for remotely sensing soil moisture with the L-band GPS bistatic radar concept, a prototype GPS bistatic radar participated in airborne measurements during the Soil Moisture Experiment 2002 (SMEX02). A 12-channel GPS navigation receiver, modified to perform bistatic radar measurements, was mounted on the NCAR C- 130 aircraft to make co-located measurements with other instruments. Narrow pulse returns and comparison of the reflected GPS signal-to-noise ratio (SNR) measurements to digital imagery and cover maps indicated that the scattering was most likely quasi-specular, originating from a small footprint on the order of the first Fresnel zone (similar to 30 in). Temporal changes were observed in the measured signals and were expected to be proportional to varying soil moisture content. To investigate this effect, the bistatic signal measurements were interpolated to a spatial grid to produce daily maps of relative change of surface soil moisture over the study region. The maps of the study region showed a transition from dry surface soil moisture conditions to wet conditions following precipitation events occurring in the middle of the study period. Additionally, the maps showed the scattered power increased in areas with localized rainfall relative to areas without precipitation. Comparing the GPS-reflected SNR measurements with L-band brightness temperatures measured coincidently by the PALS radiometer showed good agreement in the trend measured by the two sensors. The scattered signal measurements were also compared with in situ soil moisture measurements and found to follow the general soil moisture trend as a function of time. These initial results from the first controlled experiment of GPS bistatic radar for soil moisture remote sensing indicate that the technique is sensitive to temporal and spatial variations in soil moisture. (C) 2004 Elsevier Inc. All rights reserved.
C1 Univ Colorado, Dept Aerosp Engn Sci, Boulder, CO 80309 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Masters, D (reprint author), Univ Colorado, Dept Aerosp Engn Sci, CB 431-CCAR, Boulder, CO 80309 USA.
EM mastersd@colorado.edu
NR 48
TC 80
Z9 89
U1 1
U2 8
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0034-4257
J9 REMOTE SENS ENVIRON
JI Remote Sens. Environ.
PD SEP 30
PY 2004
VL 92
IS 4
BP 507
EP 520
DI 10.1016/j.rse.2004.05.016
PG 14
WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic
Technology
SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science &
Photographic Technology
GA 859UU
UT WOS:000224294200009
ER
PT J
AU Li, FQ
Jackson, TJ
Kustas, WP
Schmugge, TJ
French, AN
Cosh, MH
Bindlish, R
AF Li, FQ
Jackson, TJ
Kustas, WP
Schmugge, TJ
French, AN
Cosh, MH
Bindlish, R
TI Deriving land surface temperature from Landsat 5 and 7 during
SMEX02/SMACEX
SO REMOTE SENSING OF ENVIRONMENT
LA English
DT Article; Proceedings Paper
CT Soil Moisture Experiment Conferernce (SMEX 02)
CY JAN, 2003
CL Columbia, MD
DE land surface temperature; Landsat 5 Thematic Mapper; Landsat 7 Enhanced
Thematic Mapper
ID EMISSIVITY SEPARATION; VEGETATION INDEX; ENERGY FLUXES; INFRARED DATA;
RESOLUTION; VALIDATION; ALGORITHM; IMAGES; MODEL
AB A sequence of five high-resolution satellite-based land surface temperature (T,) images over a watershed area in Iowa were analyzed. As a part of the SMEX02 field experiment, these land surface temperature images were extracted from Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper (ETM) thermal bands. The radiative transfer model MODTRAN 4.1 was used with atmospheric profile data to atmospherically correct the Landsat data. NDVI derived from Landsat visible and near-infrared bands was used to estimate fractional vegetation cover, which in turn was used to estimate emissivity for Landsat thermal bands. The estimated brightness temperature was compared with concurrent tower based measurements. The mean absolute difference (MAD) between the satellite-based brightness temperature estimates and the tower based brightness temperature was 0.98 degreesC for Landsat 7 and 1.47 degreesC for Landsat 5, respectively. Based on these images, the land surface temperature spatial variation and its change with scale are addressed. The scaling properties of the surface temperature are important as they have significant implications for changes in land surface flux estimation between higher-resolution Landsat and regional to global sensors such as MODIS. Published by Elsevier Inc.
C1 USDA ARS, Hydrol & Remote Sensing Lab, Beltsville, MD 20705 USA.
NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA.
RP Li, FQ (reprint author), USDA ARS, Hydrol & Remote Sensing Lab, Room 104,Bldg 007 BARC W, Beltsville, MD 20705 USA.
EM fel@hydrolab.arsusda.gov
RI Cosh, MIchael/A-8858-2015
OI Cosh, MIchael/0000-0003-4776-1918
NR 35
TC 95
Z9 107
U1 2
U2 23
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0034-4257
J9 REMOTE SENS ENVIRON
JI Remote Sens. Environ.
PD SEP 30
PY 2004
VL 92
IS 4
BP 521
EP 534
DI 10.1016/j.rse.2004.02.018
PG 14
WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic
Technology
SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science &
Photographic Technology
GA 859UU
UT WOS:000224294200010
ER
PT J
AU Kawa, SR
Erickson, DJ
Pawson, S
Zhu, Z
AF Kawa, SR
Erickson, DJ
Pawson, S
Zhu, Z
TI Global CO2 transport simulations using meteorological data from the NASA
data assimilation system
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE carbon dioxide; data assimilation
ID ATMOSPHERIC CARBON-DIOXIDE; COMMUNITY CLIMATE MODEL; REFLECTED SUNLIGHT;
INTERANNUAL VARIABILITY; SATELLITE-OBSERVATIONS; SOURCE INVERSIONS;
SEASONAL CYCLE; NORTH-AMERICA; SINKS; SENSITIVITY
AB [ 1] We present a first analysis of atmospheric CO2 transport using meteorological data from the NASA finite volume data assimilation system (FVDAS). The analyzed meteorological fields are used along with climatological surface sources and sinks in an off-line, forward transport simulation for 1998 - 2000. Analysis of model diagnostics and comparisons to previous results indicates that the model performance is consistent with that of most previous global transport models. The model interhemispheric gradients along with the timing and magnitude of the CO2 seasonal cycle are discussed, providing inferences regarding the northern biosphere, tropical land, and southern ocean fluxes. Global distributions of column-integrated CO2 are presented to provide a basis for measurement requirements for the design of satellite-based instruments for atmospheric CO2 column. On the synoptic scale we find a significant benefit in using the FVDAS analyzed winds for comparisons to data. At near-equatorial observation sites, the model correctly simulates the observed atmospheric composition transition associated with the latitudinal movement of the ITCZ. Comparison to daily data from continuous analyzer sites shows the model captures a substantial amount of the observed synoptic variability due to transport changes. These results show the potential to use high temporal and spatial resolution remote sensing data to constrain CO2 surface fluxes, and they form the starting point for developing an operational CO2 assimilation system to produce high-resolution distributions of atmospheric CO2 and quantitative estimates of the global carbon budget.
C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA.
Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA.
Goddard Earth Sci & Technol Ctr, Baltimore, MD 20771 USA.
Sci Syst & Applicat Inc, Lanham, MD 20706 USA.
RP NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA.
EM stephan.r.kawa@nasa.gov
RI Kawa, Stephan/E-9040-2012; Pawson, Steven/I-1865-2014
OI Pawson, Steven/0000-0003-0200-717X
NR 53
TC 61
Z9 61
U1 0
U2 11
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 29
PY 2004
VL 109
IS D18
AR D18312
DI 10.1029/2004JD004554
PG 17
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 861IG
UT WOS:000224409200004
ER
PT J
AU Taha, G
Thomason, LW
Burton, SP
AF Taha, G
Thomason, LW
Burton, SP
TI Comparison of Stratospheric Aerosol and Gas Experiment (SAGE) II version
6.2 water vapor with balloon-borne and space-based instruments
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE water vapor; stratosphere; SAGE II; remote sensing
ID OZONE; VALIDATION
AB [1] A new version of the SAGE II data products was released in October 2003. The primary change to the algorithm dealt with improvements in the water vapor product such as eliminating the dry bias in the lower stratosphere and reducing the sensitivity to aerosol contamination. Results of an extensive comparison of SAGE II version 6.2 water vapor and various correlative measurement from balloon-borne and space-based instruments illustrate significant improvement over the previous version ( version 6.1). In general, the agreement was within 10% or less over an altitude range of 15 - 40 km when compared with frost point hygrometer, HALOE, POAM III, and ILAS and 15 - 20% when compared to MkIV. Above 40 km, SAGE II water vapor profiles are often noisy and show an increasingly positive bias. On the basis of comparison with HALOE a basic screening criteria would consist of electing measurements where the aerosol extinction coefficient at 1020 nm exceeds 2 x 10(-4) km(-1) and water vapor uncertainty exceeds 50%.
C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA.
Univ Arizona, Inst Atmospher Phys, Tucson, AZ 85721 USA.
SAIC, Hampton, VA USA.
RP Taha, G (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA.
EM fn.g.taha@larc.nasa.gov
NR 15
TC 23
Z9 24
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 29
PY 2004
VL 109
IS D18
AR D18313
DI 10.1029/2004JD004859
PG 11
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 861IG
UT WOS:000224409200012
ER
PT J
AU Weisenstein, DK
Eluszkiewicz, J
Ko, MKW
Scott, CJ
Jackman, CH
Fleming, EL
Considine, DB
Kinnison, DE
Connell, PS
Rotman, DA
AF Weisenstein, DK
Eluszkiewicz, J
Ko, MKW
Scott, CJ
Jackman, CH
Fleming, EL
Considine, DB
Kinnison, DE
Connell, PS
Rotman, DA
TI Separating chemistry and transport effects in two-dimensional models
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE modeling; stratosphere; aircraft
ID PLANETARY WAVE BREAKING; STRATOSPHERIC CLOUD PARAMETERIZATION;
INITIATIVE ASSESSMENT MODEL; MULTIPLE-SCATTERING; MIDDLE ATMOSPHERE;
OZONE DEPLETION; GRAVITY-WAVE; AIRCRAFT; SIMULATIONS; RADIATION
AB [ 1] Representation of transport in numerical models is known to be a major uncertainty in modeling of the atmosphere. Models also differ in their treatment of gas phase and heterogeneous chemistry. This paper will describe a quantitative approach to diagnosing the source of intermodel differences in ozone assessment calculations. Our approach is applied to diagnosing the differences between two-dimensional (2-D) models from Atmospheric and Environmental Research, the NASA Goddard Space Flight Center, and the Lawrence Livermore National Laboratory. Surprisingly, we find that differences due to chemical formulation are often as large as those due to transport, despite the fact that all models use the same set of reaction rate coefficients. These differences are particularly large when polar stratospheric cloud (PSC) processes are included in the models, though differences due to photolysis rates and details of the sulfate chemistry are also apparent. Perturbation calculations for a scenario including supersonic commercial aircraft operating in the 2015 stratosphere reveal that differences in the accumulation of H2O and NOy emitted by aircraft are due almost entirely to transport, while differences in ozone due to chemical formulation are evident in the lower stratosphere even without differences in H2O and NOy and without PSCs. By demonstrating a capability of separating transport and chemical differences, it is hoped that the results described in this paper will stimulate analogous studies with other models and will thus lead to a deeper understanding of intermodel similarities and differences, along with a means to quantify uncertainties in model predictions of atmospheric response to perturbations.
C1 Atmospher & Environm Res Inc, Lexington, MA 02421 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Lawrence Livermore Natl Lab, Livermore, CA 94550 USA.
Sci Syst & Applicat Inc, Lanham, MD USA.
RP Weisenstein, DK (reprint author), Atmospher & Environm Res Inc, 131 Hartwell Ave, Lexington, MA 02421 USA.
EM dkweis@aer.com; jel@aer.com; malcolm.k.ko@nasa.gov; scott@aer.com;
charles.h.jackman@nasa.gov; fleming@kahuna.gsfc.nasa.gov;
david.b.considine@nasa.gov; dkin@ucar.edu; connell2@llnl.gov;
rotman1@llnl.gov
RI Jackman, Charles/D-4699-2012; Ko, Malcolm/D-5898-2015
NR 42
TC 11
Z9 11
U1 0
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 29
PY 2004
VL 109
IS D18
AR D18310
DI 10.1029/2004JD004744
PG 26
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 861IG
UT WOS:000224409200011
ER
PT J
AU Segre, PN
McClymer, JP
AF Segre, PN
McClymer, JP
TI Fluctuations, stratification and stability in a liquid fluidized bed at
low Reynolds number
SO JOURNAL OF PHYSICS-CONDENSED MATTER
LA English
DT Article; Proceedings Paper
CT Conference on Colloidal Dispersions in External Fields
CY MAR 29-APR 01, 2004
CL Bonn Bad Godesberg, GERMANY
ID NON-BROWNIAN SPHERES; SEDIMENTING SUSPENSIONS; DIFFUSION
AB The sedimentation dynamics of extremely low polydispersity, non-colloidal, particles are studied in a liquid fluidized bed at low Reynolds number, Re much less than 1. When fluidized, the system reaches a steady state, defined where the local average volume fraction does not vary in time. In the steady state, the velocity fluctuations and the particle concentrations are found to strongly depend on height in the particle column. Using our results, we test a recently developed stability model (Segre 2002 Phys. Rein Lett. 89 254503) for steady state sedimentation. The model describes the data well, and shows that in the steady state there is a balancing of particle fluxes due to the fluctuations and the concentration gradient. Some results are also presented for the dependence of the concentration gradient in fluidized beds on particle size; the gradients become smaller as the particles become larger and fewer in number.
C1 NASA, George C Marshall Space Flight Ctr, Biophys Grp, Huntsville, AL 35812 USA.
Univ Maine, Dept Phys, Orono, ME 04469 USA.
RP Segre, PN (reprint author), NASA, George C Marshall Space Flight Ctr, Biophys Grp, Huntsville, AL 35812 USA.
EM phil.n.segre@nasa.gov
NR 18
TC 7
Z9 8
U1 1
U2 3
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0953-8984
J9 J PHYS-CONDENS MAT
JI J. Phys.-Condes. Matter
PD SEP 29
PY 2004
VL 16
IS 38
SI SI
BP S4219
EP S4230
AR PII S0953-8984(04)80665-9
DI 10.1088/0953-8984/16/38/034
PG 12
WC Physics, Condensed Matter
SC Physics
GA 863HB
UT WOS:000224550700035
ER
PT J
AU Strauss, E
Thomas, B
Yau, ST
AF Strauss, E
Thomas, B
Yau, ST
TI Enhancing electron transfer at a cytochrome c-immobilized microelectrode
and macroelectrode
SO LANGMUIR
LA English
DT Article
ID GLASSY-CARBON ELECTRODES; GRAPHITE-ELECTRODES; ELECTROCHEMICAL
OXIDATION; SOLID ELECTRODES; HEME-PROTEINS; INDIUM OXIDE; TIN OXIDE;
REDUCTION; GOLD; POTENTIALS
AB The redox reaction of cytochrome c immobilized on the bare surfaces of microelectrodes and macroscopic electrodes (macroelectrodes) composed of different planes of highly oriented pyrolytic graphite has been investigated using cyclic voltammetry. The protein-immobilized microelectrodes were fabricated using a simple masking method. For both macroelectrodes and microelectrodes, the redox reaction of immobilized cytochrome c needs to be activated by increasing the electrochemical potential maximum of cyclic voltammetry to a high positive value. The redox currents of this protein- electrode system can be enhanced using two approaches. The oxidation and reduction currents of cytochrome c adsorbed on microelectrodes that are composed of the edge plane show an anomalous enhancement compared to those for macroelectrodes composed of the basal plane. The difference in the surface chemical properties of the two kinds of electrodes results in the current anomaly. The oxidation current of the macroelectrode can be selectively enhanced by decreasing the potential minimum.
C1 CUNY Hunter Coll, Dept Phys & Astron, New York, NY 10021 USA.
George C Marshall Space Flight Ctr, BAE Syst, Huntsville, AL 35806 USA.
RP Yau, ST (reprint author), CUNY Hunter Coll, Dept Phys & Astron, New York, NY 10021 USA.
EM syau@hunter.cuny.edu
FU NCRR NIH HHS [RR-03037]; NIGMS NIH HHS [S06 GM60654]
NR 37
TC 9
Z9 9
U1 1
U2 3
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 0743-7463
J9 LANGMUIR
JI Langmuir
PD SEP 28
PY 2004
VL 20
IS 20
BP 8768
EP 8772
DI 10.1021/la049942y
PG 5
WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science,
Multidisciplinary
SC Chemistry; Materials Science
GA 856IN
UT WOS:000224039000053
PM 15379504
ER
PT J
AU Pernice, H
Garcia, P
Willner, H
Francisco, JS
Mills, FP
Allen, M
Yung, YL
AF Pernice, H
Garcia, P
Willner, H
Francisco, JS
Mills, FP
Allen, M
Yung, YL
TI Laboratory evidence for a key intermediate in the Venus atmosphere:
Peroxychloroformyl radical
SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF
AMERICA
LA English
DT Article
ID MOLECULAR-OXYGEN; PHOTOCHEMISTRY; SPECTRA
AB For two decades, the peroxychloroformyl radical, CIC(O)OO, has played a central role in models of the chemical stability of the Venus atmosphere. No confirmation, however, has been possible in the absence of laboratory measurements for CIC(O)OO. We report the isolation of CIC(O)OO in a cryogenic matrix and its infrared and ultraviolet spectral signatures. These experiments show that CIC(O)OO is thermally and photolytically stable in the Venus atmosphere. These experimental discoveries validate the existence of CIC(O)OO, confirm several longstanding model assumptions, and provide a basis for the astronomical search for this important radical species.
C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Australian Natl Univ, Ctr Resource & Environm Studies, Canberra, ACT 0200, Australia.
Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA.
Univ Wuppertal, Fachbereich C Anorgan Chem, D-42119 Wuppertal, Germany.
RP Allen, M (reprint author), CALTECH, Div Geol & Planetary Sci, Mail Code 150-21,1200 E Calif Blvd, Pasadena, CA 91125 USA.
EM mark.allen@jpl.nasa.gov
NR 24
TC 28
Z9 29
U1 0
U2 7
PU NATL ACAD SCIENCES
PI WASHINGTON
PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA
SN 0027-8424
J9 P NATL ACAD SCI USA
JI Proc. Natl. Acad. Sci. U. S. A.
PD SEP 28
PY 2004
VL 101
IS 39
BP 14007
EP 14010
DI 10.1073/pnas.0405501101
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 858SG
UT WOS:000224211400009
PM 15375212
ER
PT J
AU Durden, SL
Meagher, JP
Haddad, ZS
AF Durden, SL
Meagher, JP
Haddad, ZS
TI Satellite observations of spatial and interannual variability of
lightning and radar reflectivity
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID OPTICAL TRANSIENT DETECTOR; EL-NINO EVENT; TROPICS; TRMM
AB The authors use satellite data to examine the relationship between lightning and upper-level radar reflectivity. They find correlations between average flash rates and upper-level reflectivities over both land and ocean, although both flash rates and reflectivities are much lower over ocean than land. Analysis of the data using Empirical Orthogonal Functions (EOFs) shows similar EOFs for averaged lightning and reflectivity. In contrast, the EOFs of the anomalies of lightning and reflectivity have different spatial patterns; however, both have principal component time series that are correlated with the Southern Oscillation Index and, hence, El Nino. Differences in behavior of the lightning and reflectivity anomaly EOFs and principal components suggest that El Nino plays a smaller role in lightning anomaly than precipitation anomaly.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM sdurden@jpl.nasa.gov
NR 13
TC 6
Z9 6
U1 1
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD SEP 25
PY 2004
VL 31
IS 18
AR L18111
DI 10.1029/2004GL020384
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 857OD
UT WOS:000224126200002
ER
PT J
AU Lee, T
AF Lee, T
TI Decadal weakening of the shallow overturning circulation in the South
Indian Ocean
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID SEA-SURFACE TEMPERATURE; PACIFIC-OCEAN; ARABIAN SEA; WORLD OCEAN;
VARIABILITY; HEAT; EXCHANGE; MODEL; THERMOCLINE; TRANSPORTS
AB Satellite observations reveal a substantial weakening of the southeasterly trade wind over the South Indian Ocean during 1992-2000 and a resultant slowdown of the shallow meridional overturning circulation in this Ocean. The estimated rate of the slowdown of this circulation, 6.8+/-1.4x10(6) m(3)/s over the 9-year period, is nearly 70% of the mean strength of this circulation. Such a change has important implications to upper-ocean heat content and decadal climate variability of the Indian Ocean, as well as to the ecosystem and air-sea exchange of CO2 in the region.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Lee, T (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 300-323, Pasadena, CA 91109 USA.
EM tlee@pacific.jpl.nasa.gov
NR 31
TC 32
Z9 34
U1 1
U2 5
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD SEP 25
PY 2004
VL 31
IS 18
AR L18305
DI 10.1029/2004GL020884
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 857OD
UT WOS:000224126200005
ER
PT J
AU Shindell, DT
Schmidt, GA
AF Shindell, DT
Schmidt, GA
TI Southern Hemisphere climate response to ozone changes and greenhouse gas
increases
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID ANTARCTIC OSCILLATION; EXTRATROPICAL CIRCULATION; SURFACE-TEMPERATURE;
SIMULATIONS; VARIABILITY; TRENDS; MODES; ICE
AB While most of the Earth warmed rapidly during recent decades, surface temperatures decreased significantly over most of Antarctica. This cooling is consistent with circulation changes associated with a shift in the Southern Annular Mode (SAM). It has been suggested that both Antarctic ozone depletion and increasing greenhouses gases have contributed to these trends. We show that a climate model including the stratosphere and both composition changes reproduces the vertical structure and seasonality of observed trends. We find that the two factors have had comparable surface impacts over recent decades, though ozone dominates above the middle troposphere. Projected impacts of the two factors on circulation over the next fifty years oppose one another, resulting in minimal trends. In contrast, their effects on surface climate reinforce one another, causing a departure from the SAM pattern and a turnabout in Antarctic temperatures, which rise more rapidly than elsewhere in the Southern Hemisphere.
C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
RP NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA.
EM dshindell@giss.nasa.gov
RI Shindell, Drew/D-4636-2012; Schmidt, Gavin/D-4427-2012
OI Schmidt, Gavin/0000-0002-2258-0486
NR 25
TC 240
Z9 249
U1 3
U2 21
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD SEP 25
PY 2004
VL 31
IS 18
AR L18209
DI 10.1029/2004GL020724
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 857OD
UT WOS:000224126200003
ER
PT J
AU Stubbs, TJ
Cargill, PJ
Lockwood, M
Grande, M
Kellett, BJ
Perry, CH
AF Stubbs, TJ
Cargill, PJ
Lockwood, M
Grande, M
Kellett, BJ
Perry, CH
TI Extended cusp-like regions and their dependence on the Polar orbit,
seasonal variations, and interplanetary conditions
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
DE solar wind plasma; interplanetary magnetic fields; magnetic
reconnection; solar wind/magnetosphere interaction; magnetosheath;
magnetopause
ID ADVANCED COMPOSITION EXPLORER; HIGH-LATITUDE MAGNETOPAUSE;
MAGNETIC-FIELD; ENERGETIC IONS; BOW SHOCK; PARTICLE-PRECIPITATION;
DAYSIDE MAGNETOPAUSE; MID-ALTITUDE; MAGNETOSPHERE; RECONNECTION
AB Extended cusp-like regions (ECRs) are surveyed, as observed by the Magnetospheric Ion Composition Sensor (MICS) of the Charge and Mass Magnetospheric Ion Composition Experiment (CAMMICE) instrument aboard Polar between 1996 and 1999. The first of these ECR events was observed on 29 May 1996, an event widely discussed in the literature and initially thought to be caused by tail lobe reconnection due to the coinciding prolonged interval of strong northward IMF. ECRs are characterized here by intense fluxes of magnetosheath-like ions in the energy-per-charge range of similar to1 to 10 keV e(-1). We investigate the concurrence of ECRs with intervals of prolonged (lasting longer than 1 and 3 hours) orientations of the IMF vector and high solar wind dynamic pressure (PSW). Also investigated is the opposite concurrence, i.e., of the IMF and high PSW with ECRs. (Note that these surveys are asking distinctly different questions.) The former survey indicates that ECRs have no overall preference for any orientation of the IMF. However, the latter survey reveals that during northward IMF, particularly when accompanied by high PSW, ECRs are more likely. We also test for orbital and seasonal effects revealing that Polar has to be in a particular region to observe ECRs and that they occur more frequently around late spring. These results indicate that ECRs have three distinct causes and so can relate to extended intervals in (1) the cusp on open field lines, (2) the magnetosheath, and (3) the magnetopause indentation at the cusp, with the latter allowing magnetosheath plasma to approach close to the Earth without entering the magnetosphere.
C1 Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BW, England.
Rutherford Appleton Lab, Dept Space Sci, Didcot OX11 0QX, Oxon, England.
RP Stubbs, TJ (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Bldg 21,Room C216,Mail Code 690-4, Greenbelt, MD 20771 USA.
EM tstubbs@lepvax.gsfc.nasa.gov
RI Lockwood, Mike/G-1030-2011; Stubbs, Timothy/I-5139-2013; Grande,
Manuel/C-2242-2013
OI Lockwood, Mike/0000-0002-7397-2172; Stubbs, Timothy/0000-0002-5524-645X;
Grande, Manuel/0000-0002-2233-2618
NR 53
TC 9
Z9 9
U1 1
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD SEP 25
PY 2004
VL 109
IS A9
AR A09210
DI 10.1029/2003JA010163
PG 16
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857OQ
UT WOS:000224127600001
ER
PT J
AU Stajner, I
Wargan, K
AF Stajner, I
Wargan, K
TI Antarctic stratospheric ozone from the assimilation of occultation data
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID POAM-III; MODEL; VALIDATION; TRANSPORT; VORTEX
AB Ozone data from the solar occultation Polar Ozone and Aerosol Measurement (POAM) III instrument are included in the ozone assimilation system at NASA's Global Modeling and Assimilation Office, which uses Solar Backscatter UltraViolet/2 (SBUV/2) instrument data. Even though POAM data are available at only one latitude in the southern hemisphere on each day, their assimilation leads to more realistic ozone distribution throughout the Antarctic region, especially inside the polar vortex. Impacts of POAM data were evaluated by individual and statistical comparisons of assimilated ozone profiles with independent ozone sondes. Major improvements in ozone representation are seen in the Antarctic lower stratosphere during austral winter and spring in 1998. Limitations of assimilation of sparse occultation data are illustrated by an example.
C1 NASA, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA.
Sci Applicat Int Corp, Beltsville, MD USA.
RP Stajner, I (reprint author), NASA, Global Modeling & Assimilat Off, Code 900-3, Greenbelt, MD 20771 USA.
EM ivanka@gmao.gsfc.nasa.gov
RI Stajner, Ivanka/B-5228-2009;
OI Stajner, Ivanka/0000-0001-6103-3939; Wargan,
Krzysztof/0000-0002-3795-2983
NR 17
TC 15
Z9 16
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD SEP 24
PY 2004
VL 31
IS 18
AR L18108
DI 10.1029/2004GL020846
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 857OC
UT WOS:000224126100005
ER
PT J
AU Joughin, I
MacAyeal, DR
Tulaczyk, S
AF Joughin, I
MacAyeal, DR
Tulaczyk, S
TI Basal shear stress of the Ross ice streams from control method
inversions
SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
LA English
DT Article
DE glaciology; Antarctica; ice streams; remote sensing
ID WEST ANTARCTICA; SUBGLACIAL GEOLOGY; SURFACE VELOCITY; LATERAL DRAG;
MASS-BALANCE; FLOW; BENEATH; SHEET; TRIBUTARIES; RADAR
AB We used control method inversions to determine the basal shear stress beneath the Ross ice streams where new high-resolution velocity data sets have recently become available. The inversion algorithm was adapted from an earlier viscous bed algorithm to allow solution for the basal shear stress corresponding to a weak plastic bed. We performed several experiments using synthetic data to determine the quality of the inversions. These experiments indicate that with high-quality surface elevation data (e.g., errors <5 m), the inversions are relatively robust with respect to errors in ice flow velocity and bed topography. The inversions are consistent with seismic and borehole observations and indicate that the Ross ice streams lie atop a bed that is nearly everywhere weak. In contrast, the tributaries feeding these ice streams overlie alternating patches of strong and weak bed.
C1 CALTECH, Jet Prop Lab, Pasadena, CA USA.
Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA.
Univ Calif Santa Cruz, Dept Earth Sci, Santa Cruz, CA 95064 USA.
RP Joughin, I (reprint author), Univ Washington, Appl Phys Lab, 1013 NE 40th St, Seattle, WA 98105 USA.
EM ian@apl.washington.edu; drm7@midway.uchicago.edu; tulaczyk@es.ucsc.edu
RI Joughin, Ian/A-2998-2008;
OI Joughin, Ian/0000-0001-6229-679X; MacAyeal, Douglas/0000-0003-0647-6176
NR 52
TC 84
Z9 84
U1 2
U2 21
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9313
EI 2169-9356
J9 J GEOPHYS RES-SOL EA
JI J. Geophys. Res.-Solid Earth
PD SEP 24
PY 2004
VL 109
IS B9
AR B09405
DI 10.1029/2003JB002960
PG 20
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 857ON
UT WOS:000224127300001
ER
PT J
AU Siegert, MJ
Welch, B
Morse, D
Vieli, A
Blankenship, DD
Joughin, I
King, EC
Vieli, GJMCL
Payne, AJ
Jacobel, R
AF Siegert, MJ
Welch, B
Morse, D
Vieli, A
Blankenship, DD
Joughin, I
King, EC
Vieli, GJMCL
Payne, AJ
Jacobel, R
TI Ice flow direction change in interior West Antarctica
SO SCIENCE
LA English
DT Article
ID PENETRATING RADAR; STREAM; SHEET; ZONE; AGE
AB Upstream of Byrd Station (West Antarctica), ice-penetrating radar data reveal a distinctive fold structure within the ice, in which isochronous layers are unusually deep. The fold has an axis more than 50 kilometers long, which is aligned up to 45degrees to the ice flow direction. Although explanations for the fold's formation under the present flow are problematic, it can be explained if flow was parallel to the fold axis similar to 1500 years ago. This flow change may be associated with ice stream alterations nearer the margin. If this is true, central West Antarctica may respond to future alterations more than previously thought.
C1 Univ Bristol, Sch Geog Sci, Bristol Glaciol Ctr, Ctr Polar Observat & Modelling, Bristol BS8 1SS, Avon, England.
St Olaf Coll, Dept Phys, Northfield, MN 55057 USA.
Univ Texas, John A & Katherine G Jackson Sch Geosci, Inst Geophys, Austin, TX 78759 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
British Antarctic Survey, Div Phys Sci, Cambridge CB3 0ET, England.
RP Siegert, MJ (reprint author), Univ Bristol, Sch Geog Sci, Bristol Glaciol Ctr, Ctr Polar Observat & Modelling, Bristol BS8 1SS, Avon, England.
EM m.j.siegert@bristot.ac.uk
RI Siegert, Martin/A-3826-2008; payne, antony/A-8916-2008; Blankenship,
Donald/G-5935-2010; Vieli, Andreas/A-6767-2011; Joughin, Ian/A-2998-2008
OI Siegert, Martin/0000-0002-0090-4806; payne, antony/0000-0001-8825-8425;
Joughin, Ian/0000-0001-6229-679X
NR 22
TC 26
Z9 28
U1 0
U2 2
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
J9 SCIENCE
JI Science
PD SEP 24
PY 2004
VL 305
IS 5692
BP 1948
EP 1951
DI 10.1126/science.1101072
PG 4
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 857RM
UT WOS:000224136000043
PM 15448266
ER
PT J
AU Rinsland, CP
Mahieu, E
Zander, R
Goldman, A
Wood, S
Chiou, L
AF Rinsland, CP
Mahieu, E
Zander, R
Goldman, A
Wood, S
Chiou, L
TI Free tropospheric measurements of formic acid (HCOOH) from infrared
ground-based solar absorption spectra: Retrieval approach, evidence for
a seasonal cycle, and comparison with model calculations
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE troposphere; atmospheric chemistry; remote sensing
ID MOLECULAR SPECTROSCOPIC DATABASE; WESTERN PACIFIC-OCEAN; ACETIC-ACIDS;
CHEMICAL CHARACTERISTICS; CONTINENTAL OUTFLOW; LOWER STRATOSPHERE;
CARBOXYLIC-ACIDS; BIOMASS FIRES; ORGANIC-ACIDS; TRACE GASES
AB The seasonal variation of the free tropospheric volume mixing ratio of formic acid (HCOOH) has been derived from high-spectral-resolution solar absorption spectra recorded with the Fourier transform spectrometer in the U. S. National Solar Observatory facility on Kitt Peak (31.9degreesN, 111.6degreesE, 2.09 km altitude) at a typical spectral resolution of 0.005 cm(-1). The spectra have been analyzed with the SFIT2 algorithm, which is based on a semiempirical application of the optimal estimation method. Absorption by HCOOH is weak in these solar spectra, but successful retrievals have been obtained with a new procedure that fits the HCOOH nu(6) band Q branch at 1105 cm(-1) simultaneously with a window to account for a temperature-sensitive HDO line, which overlaps the HCOOH Q branch. After retaining only the best measurements from a database extending from June 1980 to October 2002 the retrievals show a seasonal variation, with a summer maximum and a winter minimum. Average 2.09-10 km volume mixing ratios binned in 3 month intervals range from a maximum of 792+/-323 parts per trillion by volume (pptv), or 10(-12), in July-September to a minimum of 313+/-175 pptv in October-December, with the uncertainties corresponding to statistical means from daily averages. The results are compared with previously reported measurements and model calculations.
C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA.
Univ Liege, Inst Astrophys & Geophys, B-4000 Liege, Belgium.
Univ Denver, Dept Phys, Denver, CO 80208 USA.
Natl Inst Water & Atmospher Res Ltd, Omakau, Central Otago, New Zealand.
Sci Applicat Int Corp, Hampton, VA 23666 USA.
RP NASA, Langley Res Ctr, Mail Stop 401A, Hampton, VA 23681 USA.
EM c.p.rinsland@larc.nasa.gov; emmanuel.mahieu@ulg.ac.be;
r.zander@ulg.ac.be; goldman@acd.ucar.edu; s.wood@niwa.co.nz;
l.s.chiou@larc.nasa.gov
NR 47
TC 20
Z9 20
U1 1
U2 4
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 23
PY 2004
VL 109
IS D18
AR D18308
DI 10.1029/2004JD004917
PG 8
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 857OG
UT WOS:000224126500011
ER
PT J
AU Wood, SW
Batchelor, RL
Goldman, A
Rinsland, CP
Connor, BJ
Murcray, FJ
Stephen, TM
Heuff, DN
AF Wood, SW
Batchelor, RL
Goldman, A
Rinsland, CP
Connor, BJ
Murcray, FJ
Stephen, TM
Heuff, DN
TI Ground-based nitric acid measurements at Arrival Heights, Antarctica,
using solar and lunar Fourier transform infrared observations
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE stratosphere; polar; winter
ID FTIR MEASUREMENTS; LIGHT-SOURCE; TRACE GASES; HNO3; OZONE; STRATOSPHERE;
MOON; UARS; DENITRIFICATION; VALIDATION
AB Nitric acid plays an important role in processes leading to stratospheric ozone loss in polar regions. Spectroscopic absorption measurements of nitric acid have been made during the sunlit part of the Antarctic year at Arrival Heights (78degreesS, 167degreesE) since the late 1980s. This paper presents the first extension of these nitric acid measurements through the winter, using the Moon as a light source. Both solar and lunar measurements for the years 1998-2003 are presented. For the lunar measurements, additional corrections owing to emission of the atmosphere and the instrument must be made. The measurements show that the column amount of nitric acid within the polar vortex continues to increase after polar sunset reaching values of similar to2.5x10(16) molecules cm(-2) similar to1 month after sunset. When temperatures become low enough for the condensation of water and nitric acid molecules, polar stratospheric clouds form, and rapid depletion of the gaseous nitric acid column is observed. The measurements have captured this event particularly well in 2002. At the time of the polar sunrise the column amounts of nitric acid are extremely depleted and are as low as 0.5x10(16) molecules cm(-2). During the spring period the site can sample air from both inside and outside the polar vortex. Inside the vortex the observed gradual recovery of HNO3 in the spring and summer months is consistent with predictions of denitrification occurring during the Antarctic winter. For measurements outside the vortex, higher HNO3 columns are observed.
C1 Natl Inst Water & Atmospher Res, Central Otago 9182, Omakau, New Zealand.
Univ Canterbury, Dept Phys & Astron, Canterbury 8020, New Zealand.
Univ Denver, Dept Phys, Denver, CO 80208 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Wood, SW (reprint author), Natl Inst Water & Atmospher Res, Private Bag 50061, Central Otago 9182, Omakau, New Zealand.
EM s.wood@niwa.co.nz; r.batchelor@niwa.co.nz; goldman@acd.ucar.edu;
c.p.rinsland@larc.nasa.gov; b.connor@niwa.co.nz; fmurcray@du.edu;
d.heuff@canterbury.ac.nz
NR 30
TC 11
Z9 11
U1 0
U2 0
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 23
PY 2004
VL 109
IS D18
AR D18307
DI 10.1029/2004JD004665
PG 9
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 857OG
UT WOS:000224126500006
ER
PT J
AU Beirle, S
Platt, U
Wenig, M
Wagner, T
AF Beirle, S
Platt, U
Wenig, M
Wagner, T
TI Highly resolved global distribution of tropospheric NO2 using GOME
narrow swath mode data
SO ATMOSPHERIC CHEMISTRY AND PHYSICS
LA English
DT Article
ID OZONE MONITORING EXPERIMENT; EMISSIONS; RETRIEVAL; SPACE; BAND
AB The Global Ozone Monitoring Experiment (GOME) allows the retrieval of tropospheric vertical column densities (VCDs) of NO2 on a global scale. Regions with enhanced industrial activity can clearly be detected, but the standard spatial resolution of the GOME ground pixels (320 x 40 km(2)) is insufficient to resolve regional trace gas distributions or individual cities.
Every 10 days within the nominal GOME operation, measurements are executed in the so called narrow swath mode with a much better spatial resolution (80 x 40 km(2)). We use this data (1997-2001) to construct a detailed picture of the mean global tropospheric NO2 distribution. Since - due to the narrow swath - the global coverage of the high resolution observations is rather poor, it has proved to be essential to deseasonalize the single narrow swath mode observations to retrieve adequate mean maps. This is done by using the GOME backscan information.
The retrieved high resolution map illustrates the shortcomings of the standard size GOME pixels and reveals an unprecedented wealth of details in the global distribution of tropospheric NO2. Localised spots of enhanced NO2 VCD can be directly associated to cities, heavy industry centers and even large power plants. Thus our result helps to check emission inventories.
The small spatial extent of NO2 "hot spots" allows us to estimate an upper limit of the mean lifetime of boundary layer NOX of 17 h on a global scale.
The long time series of GOME data allows a quantitative comparison of the narrow swath mode data to the nominal resolution. Thus we can analyse the dependency of NO2 VCDs on pixel size. This is important for comparing GOME data to results of new satellite instruments like SCIAMACHY (launched March 2002 on ENVISAT), OMI (launched July 2004 on AURA) or GOME II (to be launched 2005) with an improved spatial resolution.
C1 Univ Heidelberg, Inst Umweltphys, D-6900 Heidelberg, Germany.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Beirle, S (reprint author), Univ Heidelberg, Inst Umweltphys, D-6900 Heidelberg, Germany.
EM beirle@iup.uni-heidelberg.de
RI Wenig, Mark/K-7279-2012
NR 29
TC 31
Z9 33
U1 0
U2 6
PU EUROPEAN GEOSCIENCES UNION
PI KATLENBURG-LINDAU
PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY
SN 1680-7324
J9 ATMOS CHEM PHYS
JI Atmos. Chem. Phys.
PD SEP 22
PY 2004
VL 4
BP 1913
EP 1924
PG 12
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 855ZC
UT WOS:000224012400001
ER
PT J
AU Rignot, E
Casassa, G
Gogineni, P
Krabill, W
Rivera, A
Thomas, R
AF Rignot, E
Casassa, G
Gogineni, P
Krabill, W
Rivera, A
Thomas, R
TI Accelerated ice discharge from the Antarctic Peninsula following the
collapse of Larsen B ice shelf
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID BREAK-UP; GREENLAND; SHEETS; FLOW
AB Interferometric synthetic-aperture radar data collected by ERS-1/2 and Radarsat-1 satellites show that Antarctic Peninsula glaciers sped up significantly following the collapse of Larsen B ice shelf in 2002. Hektoria, Green and Evans glaciers accelerated eightfold between 2000 and 2003 and decelerated moderately in 2003. Jorum and Crane glaciers accelerated twofold in early 2003 and threefold by the end of 2003. In contrast, Flask and Leppard glaciers, further south, did not accelerate as they are still buttressed by an ice shelf. The mass loss associated with the flow acceleration exceeds 27 km 3 per year, and ice is thinning at rates of tens of meters per year. We attribute this abrupt evolution of the glaciers to the removal of the buttressing ice shelf. The magnitude of the glacier changes illustrates the importance of ice shelves on ice sheet mass balance and contribution to sea level change.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Ctr Estudios Cient, Valdivia, Chile.
Univ Kansas, Radar Syst & Remote Sensing Lab, Lawrence, KS 66045 USA.
NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Isl, VA 23337 USA.
EG&G Serv, Wallops Isl, VA 23337 USA.
RP Rignot, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 200-227, Pasadena, CA 91109 USA.
EM eric.rignot@jpl.nasa.gov; gc@cecs.cl; gogineni@ittc.ku.edu;
krabill@osb1.wff.nasa.gov; arivera@blackhole.cecs.cl;
thomas@aim1.wff.nasa.gov
RI Rignot, Eric/A-4560-2014
OI Rignot, Eric/0000-0002-3366-0481
NR 22
TC 261
Z9 263
U1 9
U2 69
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD SEP 22
PY 2004
VL 31
IS 18
AR L18401
DI 10.1029/2004GL020697
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 857OA
UT WOS:000224125900003
ER
PT J
AU Scambos, TA
Bohlander, JA
Shuman, CA
Skvarca, P
AF Scambos, TA
Bohlander, JA
Shuman, CA
Skvarca, P
TI Glacier acceleration and thinning after ice shelf collapse in the Larsen
B embayment, Antarctica
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID PENINSULA; RETREAT; DISINTEGRATION; SHEET
AB Ice velocities derived from five Landsat 7 images acquired between January 2000 and February 2003 show a two- to six-fold increase in centerline speed of four glaciers flowing into the now-collapsed section of the Larsen B Ice Shelf. Satellite laser altimetry from ICESat indicates the surface of Hektoria Glacier lowered by up to 38 +/- 6 m in a six-month period beginning one year after the break-up in March 2002. Smaller elevation losses are observed for Crane and Jorum glaciers over a later 5-month period. Two glaciers south of the collapse area, Flask and Leppard, show little change in speed or elevation. Seasonal variations in speed preceding the large post-collapse velocity increases suggest that both summer melt percolation and changes in the stress field due to shelf removal play a major role in glacier dynamics.
C1 Univ Colorado, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA.
NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 20771 USA.
Inst Antartico Argentino, Div Glaciol, Buenos Aires, DF, Argentina.
RP Scambos, TA (reprint author), Univ Colorado, Natl Snow & Ice Data Ctr, 1540 30th St, Boulder, CO 80309 USA.
EM teds@icehouse.colorado.edu
RI Scambos, Ted/B-1856-2009
NR 19
TC 299
Z9 305
U1 8
U2 71
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD SEP 22
PY 2004
VL 31
IS 18
AR L18402
DI 10.1029/2004GL020670
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 857OA
UT WOS:000224125900002
ER
PT J
AU Feldman, WC
Prettyman, TH
Maurice, S
Plaut, JJ
Bish, DL
Vaniman, DT
Mellon, MT
Metzger, AE
Squyres, SW
Karunatillake, S
Boynton, WV
Elphic, RC
Funsten, HO
Lawrence, DJ
Tokar, RL
AF Feldman, WC
Prettyman, TH
Maurice, S
Plaut, JJ
Bish, DL
Vaniman, DT
Mellon, MT
Metzger, AE
Squyres, SW
Karunatillake, S
Boynton, WV
Elphic, RC
Funsten, HO
Lawrence, DJ
Tokar, RL
TI Global distribution of near-surface hydrogen on Mars
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
DE composition; glaciation; Mars
ID GROUND ICE; WATER-ICE; SUMMER TEMPERATURES; EPITHERMAL NEUTRONS; MARTIAN
ATMOSPHERE; RAY SPECTROMETER; CO2 FROST; ODYSSEY; STABILITY; EVOLUTION
AB Neutron data observed using the Neutron Spectrometer aboard 2001 Mars Odyssey provide a lower limit to the global inventory of Martian water-equivalent hydrogen. Hydrogen-rich deposits ranging between about 20% and 100% water-equivalent by mass are found poleward of +/-50degrees latitude, and less rich, but significant, deposits are found at near-equatorial latitudes. The equatorial deposits between +/-45degrees latitude range between 2% and 10% water-equivalent hydrogen by mass and reach their maximum in two regions that straddle the 0-km elevation contour. Higher water abundances, up to similar to11%, are required in subsurface regolith of some equatorial regions if the upper 10 g/cm(2) of regolith is desiccated, as suggested on average by comparison of epithermal and fast neutron data. The hydrogen contents of surface soils in the latitude range between 50degrees and 80degrees north and south are equal within data uncertainties. A lower-limit estimate of the global inventory of near surface hydrogen amounts to a global water layer about 14 cm thick if the reservoir sampled from orbit is assumed to be 1 m thick.
C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA.
Observ Midi Pyrenees, F-31400 Toulouse, France.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA.
Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA.
Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA.
RP Los Alamos Natl Lab, Mail Stop D466, Los Alamos, NM 87545 USA.
EM wfeldman@lanl.gov; thp@lanl.gov
RI Karunatillake, Suniti/A-5934-2009; Funsten, Herbert/A-5702-2015; Mellon,
Michael/C-3456-2016; Lawrence, David/E-7463-2015
OI Karunatillake, Suniti/0000-0001-9891-1432; Funsten,
Herbert/0000-0002-6817-1039; Lawrence, David/0000-0002-7696-6667
NR 46
TC 199
Z9 199
U1 3
U2 28
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9097
EI 2169-9100
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD SEP 22
PY 2004
VL 109
IS E9
AR E09006
DI 10.1029/2003JE002160
PG 13
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 857OL
UT WOS:000224127100001
ER
PT J
AU Khan, A
Mosegaard, K
Williams, JG
Lognonne, P
AF Khan, A
Mosegaard, K
Williams, JG
Lognonne, P
TI Does the Moon possess a molten core? Probing the deep lunar interior
using results from LLR and Lunar Prospector
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
DE mathematical geophysics; Moon; planetology; solid surface
ID IMPACT-GENERATED DISK; INVERSE PROBLEMS; SEISMIC DATA; GIANT IMPACT;
GRAVITY-FIELD; EARTH; CONSTRAINTS; EVOLUTION; MODELS; MANTLE
AB It is the main purpose of this study to examine the deeper structure of the Moon in the light of four numbers. These are lunar mass M, mean moment of inertia I, second degree tidal Love number k(2), and the quality factor Q, accounting for tidal dissipation within the solid body of the Moon. The former two have been measured by Lunar Prospector to high precision, and more than 30 years of lunar laser ranging (LLR) data have led to an estimate of the second degree tidal Love number and quality factor. The inverse problem dealt with here of obtaining information on the lunar density and S wave velocity profile from the four numbers follows our earlier investigations by employing an inverse Monte Carlo sampling method. We present a novel way of analyzing the outcome using the Bayes factor. The advantage lies in the fact that rather than just looking at a subset of sampled models, we investigate all the information sampled in different runs, i.e., take into account all samples, in order to estimate their relative plausibility. The most likely outcome of our study, based on the data, their uncertainties, and prior information, is a central core with a most probable S wave velocity close to 0 km/s, density of similar to7.2 g/cm(3) and radius of about 350 km. This is interpreted as implying the presence of a molten or partially molten Fe core, in line with evidence presented earlier using LLR regarding the dissipation within the Moon.
C1 Inst Phys Globe Paris, Dept Geophys Spatiale & Planetaire, F-94107 St Maur des Fosses, France.
Univ Copenhagen, Niels Bohr Inst, Dept Geophys, DK-2100 Copenhagen, Denmark.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Khan, A (reprint author), Inst Phys Globe Paris, Dept Geophys Spatiale & Planetaire, 4 Ave Neptune, F-94107 St Maur des Fosses, France.
EM khan@ipgp.jussieu.fr; klaus@gfy.ku.dk; james.g.williams@jpl.nasa.gov;
lognonne@ipgp.jussieu.fr
RI Lognonne, Philippe/F-8846-2010
NR 86
TC 48
Z9 48
U1 1
U2 11
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD SEP 22
PY 2004
VL 109
IS E9
AR E09007
DI 10.1029/2004JE002294
PG 25
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 857OL
UT WOS:000224127100004
ER
PT J
AU Potts, LV
von Frese, RR
Leftwich, TE
Taylor, PT
Shum, CK
Li, RX
AF Potts, LV
von Frese, RR
Leftwich, TE
Taylor, PT
Shum, CK
Li, RX
TI Gravity-inferred crustal attributes of visible and buried impact basins
on Mars
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
DE craters; crust; Mars
ID SPHERICAL-EARTH GRAVITY; CORRELATED FREE-AIR; MULTIRING BASINS; LUNAR
BASINS; EVOLUTION; TOPOGRAPHY; ANOMALIES; TERRAIN; ORIGIN; ORIENTALE
AB The impact basins of Mars reveal important insights on Martian tectonic evolution. They involve strongly disrupted, depressed regions of crust with likely enhanced porosity and permeability that may locally concentrate water and other crustal fluids. Hence the crustal properties of impact basins can also be important in the hunt for water and related clues for life on Mars. We assess the crustal details of impact basins by separating the Mars Global Surveyor free-air anomalies into terrain-correlated and terrain-decorrelated components. The separation is based on the correlation spectrum between the free-air anomalies and the gravity effects evaluated from the topography mapped by the Mars Orbital Laser Altimeter (MOLA). For topographically visible multiring basins like Isidis, striking circular patterns of alternating terrain-correlated free-air maxima and minima mark the uncompensated components of the central mantle plug and surrounding rings. The first vertical derivatives of these anomalies effectively estimate the basin ring locations and a transient cavity depth-to-diameter ratio of 0.09 that is consistent with the ratio observed for lunar nearside multiring basins. For the Isidis Basin we obtain an excavation depth of roughly 66 km that reflects considerably disrupted crust for concentrating local fluids since the Noachian impact. Furthermore, the related crustal terrain-decorrelated free-air anomalies suggest up to 2 km of high-density basin fill may cap the central basin. Subtle quasi-circular depressions in the relatively featureless MOLA terrain of the northern hemisphere have identified potentially buried impact basins [Frey et al., 2002]. An altimetry depression in Acidalia Planitia and another in Utopia are also associated with ringed patterns of terrain-decorrelated free-air anomalies that may mark the uncompensated mass effects of buried impact basins. The gravity-derived transient excavation depths for these inferred basins are roughly 41 and 20 km, respectively, while the related ring diameters (D) follow the ubiquitous root2D rule of planetary impact basins. The crust of these buried basins is likely to contain water at higher levels than the crust of the equatorial basins that was substantially dewatered with the development of the great northern basin. Hence analyzing surface fractures, faults, and other crustal discontinuities that can tap the more saturated crust of these inferred buried basins may facilitate the hunt for water on Mars.
C1 Ohio State Univ, Lab Space Geodesy & Remote Sensing Res, Columbus, OH 43210 USA.
Ohio State Univ, Dept Geol Sci, Columbus, OH 43210 USA.
NASA, Goddard Space Flight Ctr, Geodynam Branch, Greenbelt, MD 20771 USA.
Ohio State Univ, Dept Civil & Environm Engn & Geodet Sci, Columbus, OH 43210 USA.
RP Potts, LV (reprint author), Ohio State Univ, Lab Space Geodesy & Remote Sensing Res, Columbus, OH 43210 USA.
EM potts.3@osu.edu
RI Taylor, Patrick/D-4707-2012
OI Taylor, Patrick/0000-0002-1212-9384
NR 56
TC 5
Z9 5
U1 0
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD SEP 22
PY 2004
VL 109
IS E9
AR E09009
DI 10.1029/2003JE002225
PG 11
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 857OL
UT WOS:000224127100002
ER
PT J
AU Gerard, JC
Grodent, D
Gustin, J
Saglam, A
Clarke, JT
Trauger, JT
AF Gerard, JC
Grodent, D
Gustin, J
Saglam, A
Clarke, JT
Trauger, JT
TI Characteristics of Saturn's FUV aurora observed with the Space Telescope
Imaging Spectrograph
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
DE ultraviolet aurora; Saturn; magnetosphere; electron precipitation;
spectroscopy; electron energy
ID POLAR IONOSPHERIC FLOWS; ELECTRON-PRECIPITATION; MAGNETIC-FIELD; OVAL;
MODEL; MAGNETOSPHERE; EMISSION; HYDROGEN; EUV
AB [1] We analyze a set of 15 FUV images obtained between October 1997 and January 2001 with the Hubble Space Telescope Imaging Spectrograph (STIS), providing a good view of Saturn's south auroral oval. It is found that the morphology and brightness distribution of the aurora are dynamical with variations occurring on time scales of hours or less. The dayside main oval lies between 70degrees and 80degrees and is generally brighter and thinner in the morning than in the afternoon sector. The afternoon sector is characterized by more diffuse emission at higher latitudes. Weak emission is also observed poleward of the main oval up to the pole. A spot of enhanced auroral precipitation, tentatively identified as the optical signature of the dayside cusp, is sometimes observed poleward of the main oval in the noon sector, especially during periods when the morning arc is not fully developed. A spiral structure of the main oval with arcs at two latitudes in the same sector is occasionally observed. The brightness of the main oval ranges from below the STIS threshold of 1 kR of H-2 emission up to similar to 75 kR. The total electron precipitated power varies between 20 and 140 GW, that is, comparable to the Earth's active aurora but about two orders of magnitude less than on Jupiter. An increasing trend of the precipitated power between the 1997 and the 2000 - 2001 observations may be related to the rising solar activity. Six spectra of the aurora in the noon sector covering the 1200 - 1700 Angstrom range are dominated by emissions of the Lyman-alpha line and H-2 Werner and Lyman bands. Their comparison with a synthetic model of electron excited H-2 emissions indicates the presence of a weak absorption below 1400 Angstrom by a column of methane ranging between 7 x 10(15) and 2 x 10(16) cm(-2). The corresponding energy of the primary auroral electrons is estimated 12 +/- 3 keV, using a low-latitude model atmosphere based on Voyager occultation measurements. The main oval brightness and the characteristic electron energy are generally consistent with recent models of Saturn's aurora, which colocate the main oval with the narrow upward field-aligned current system associated with departure from plasma corotation near the open-closed field line boundary. The latitude of the bright morning arc is somewhat lower than model predictions based on the plasma flow velocity measured by Voyager in the middle magnetosphere.
C1 Univ Liege, Lab Phys Atmospher & Planetaire, B-4000 Liege, Belgium.
Boston Univ, Ctr Space Phys, Boston, MA 02215 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Univ Liege, Lab Phys Atmospher & Planetaire, B-4000 Liege, Belgium.
EM jc.gerard@ulg.ac.be; d.grodent@ulg.ac.be; j.gustin@ulg.ac.be;
jclarke@bu.edu; jtt@lyot.jpl.nasa.gov
RI Clarke, John/C-8644-2013;
OI GERARD, Jean-Claude/0000-0002-8565-8746
NR 40
TC 118
Z9 118
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9380
EI 2169-9402
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD SEP 22
PY 2004
VL 109
IS A9
AR A09207
DI 10.1029/2004JA010513
PG 10
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857OP
UT WOS:000224127500005
ER
PT J
AU Richardson, IG
Cane, HV
AF Richardson, IG
Cane, HV
TI The fraction of interplanetary coronal mass ejections that are magnetic
clouds: Evidence for a solar cycle variation
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID GEOMAGNETIC STORMS; 1 AU; LASCO; DECREASES; TOPOLOGY; HELIOS; FIELD;
WIND
AB "Magnetic clouds'' (MCs) are a subset of interplanetary coronal mass ejections (ICMEs) characterized by enhanced magnetic fields with an organized rotation in direction, and low plasma beta. Though intensely studied, MCs only constitute a fraction of all ICMEs detected in the solar wind. A comprehensive survey of ICMEs in the near-Earth solar wind during the ascending, maximum and early declining phases of solar cycle 23 in 1996-2003 shows that the MC fraction varied with the phase of the solar cycle, from similar to100% (though with low statistics) at solar minimum to similar to15% at solar maximum. A similar trend is evident in near-Earth observations during solar cycles 20-21, while Helios 1/2 observations at 0.3-1.0 AU show a weaker trend and larger MC fraction.
C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
Univ Tasmania, Sch Math & Phys, Hobart, Tas, Australia.
RP Richardson, IG (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA.
EM richardson@lheavx.gsfc.nasa.gov; hilary.cane@utas.edu.au
NR 26
TC 21
Z9 21
U1 0
U2 4
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD SEP 21
PY 2004
VL 31
IS 18
AR L18804
DI 10.1029/2004GL020958
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 857NZ
UT WOS:000224125800005
ER
PT J
AU Greivenkamp, JE
Gappinger, RO
AF Greivenkamp, JE
Gappinger, RO
TI Design of a nonnull interferometer for aspheric wave fronts
SO APPLIED OPTICS
LA English
DT Article
ID SUB-NYQUIST INTERFEROMETRY
AB The presence of highly aspheric wave fronts in an interferometer leads to a need for system calibration, and this calibration requirement affects the design of the interferometer. Dynamic range, vignetting, and the ability to characterize components all must be considered during the design stages. The interferometer must be designed with respect to wave-front propagation as opposed to reference sphere aberrations. A nonnull interferometer for measurement of aspheric transmitted wave fronts has been developed, and the design process is described. Transmitted wave fronts for a conformal window and a progressive-addition bifocal lens have been measured to demonstrate the applicability of the system to aspheric testing. (C) 2004 Optical Society of America.
C1 Univ Arizona, Ctr Opt Sci, Tucson, AZ 85721 USA.
Jet Prop Lab, Pasadena, CA 91109 USA.
RP Greivenkamp, JE (reprint author), Univ Arizona, Ctr Opt Sci, 1630 E Univ Blvd, Tucson, AZ 85721 USA.
EM greiven@arizona.edu
NR 14
TC 31
Z9 36
U1 1
U2 6
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 1559-128X
EI 2155-3165
J9 APPL OPTICS
JI Appl. Optics
PD SEP 20
PY 2004
VL 43
IS 27
BP 5143
EP 5151
DI 10.1364/AO.43.005143
PG 9
WC Optics
SC Optics
GA 854SF
UT WOS:000223922900002
PM 15473233
ER
PT J
AU Gappinger, RO
Greivenkamp, JE
AF Gappinger, RO
Greivenkamp, JE
TI Iterative reverse optimization procedure for calibration of aspheric
wave-front measurements on a nonnull interferometer
SO APPLIED OPTICS
LA English
DT Article
ID ERRORS
AB The accuracy of interferometric measurements made with a nonnull configuration is degraded by test-dependent aberrations. Calibration of the data can be done with reverse optimization methods. An iterative reverse optimization process that improves efficiency and eliminates sensitive merit function weighting issues is described. The process is shown to calibrate a nonnull interferometric measurement of a wave front with more than 200 waves of departure to an accuracy of 0.16 waves peak to valley and 0.02 waves rms. (C) 2004 Optical Society of America.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Arizona, Ctr Opt Sci, Tucson, AZ 85721 USA.
RP Gappinger, RO (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 306-388, Pasadena, CA 91109 USA.
EM robert.o.grappinger@jpl.nasa.gov
NR 13
TC 23
Z9 25
U1 2
U2 2
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 1559-128X
EI 2155-3165
J9 APPL OPTICS
JI Appl. Optics
PD SEP 20
PY 2004
VL 43
IS 27
BP 5152
EP 5161
DI 10.1364/AO.43.005152
PG 10
WC Optics
SC Optics
GA 854SF
UT WOS:000223922900003
PM 15473234
ER
PT J
AU Coyle, DB
Kay, RB
Stysley, PR
Poulios, D
AF Coyle, DB
Kay, RB
Stysley, PR
Poulios, D
TI Efficient, reliable, long-lifetime, diode-pumped Nd : YAG laser for
space-based vegetation topographical altimetry
SO APPLIED OPTICS
LA English
DT Article
ID RESONATORS
AB A highly efficient, diode-pumped, Nd:YAG laser is described. The oscillator utilizes an unstable resonator design with a Gaussian reflectivity output coupler and a side-pumped zigzag slab gain medium. The laser produces 18-mJ, 10-ns pulses at a repetition rate of 242 Hz in a near-TEM00 mode with an optical efficiency of up to 14%. An extended performance test was recently concluded in which the transmitter operated at reduced output for more than 4.8 x 10(9) shots with no optical damage. Design criteria, beam quality, and lifetime data are presented. (C) 2004 Optical Society of America.
C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
American Univ, Dept Phys, Washington, DC 20016 USA.
RP Coyle, DB (reprint author), NASA, Goddard Space Flight Ctr, Code 920, Greenbelt, MD 20771 USA.
EM barry@comfed.gsfe.nasa.gov
NR 19
TC 20
Z9 22
U1 0
U2 1
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 1559-128X
EI 2155-3165
J9 APPL OPTICS
JI Appl. Optics
PD SEP 20
PY 2004
VL 43
IS 27
BP 5236
EP 5242
DI 10.1364/AO.43.005236
PG 7
WC Optics
SC Optics
GA 854SF
UT WOS:000223922900014
PM 15473245
ER
PT J
AU Wei, CY
Srivastava, D
AF Wei, CY
Srivastava, D
TI Nanomechanics of carbon nanofibers: Structural and elastic properties
SO APPLIED PHYSICS LETTERS
LA English
DT Article
ID NANOTUBES; GROWTH; ARRAYS
AB A general analytic expression for the Young's modulus of a range of carbon nanofibers (CNFs) with single or multishell nanocone or cone stacked structures has been developed from continuum elastic theory. The Young's modulus of a single-shell nanocone is found to be cos(4) theta of that of an equivalent single-wall carbon nanotube (CNT). The CNFs of short lengths and small tilting angles have very large Young's modulus comparable to that of single or multiwall CNTs, whereas the inverse is true for the CNFs with long lengths and large tilting angles. The dependence of the stiffness of CNFs on various structural parameters has been predicted by the model, validated through full-scale molecular dynamics simulations, and categorized for scanning probe tip or reinforcing fiber type applications. (C) 2004 American Institute of Physics.
C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Wei, CY (reprint author), NASA, Ames Res Ctr, MS 229-1, Moffett Field, CA 94035 USA.
EM cwei@nas.nasa.gov
NR 16
TC 60
Z9 60
U1 1
U2 11
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0003-6951
J9 APPL PHYS LETT
JI Appl. Phys. Lett.
PD SEP 20
PY 2004
VL 85
IS 12
BP 2208
EP 2210
DI 10.1063/1.1792797
PG 3
WC Physics, Applied
SC Physics
GA 857UW
UT WOS:000224145300018
ER
PT J
AU Cassell, AM
Li, J
Stevens, RMD
Koehne, JE
Delzeit, L
Ng, HT
Ye, Q
Han, J
Meyyappan, M
AF Cassell, AM
Li, J
Stevens, RMD
Koehne, JE
Delzeit, L
Ng, HT
Ye, Q
Han, J
Meyyappan, M
TI Vertically aligned carbon nanotube heterojunctions
SO APPLIED PHYSICS LETTERS
LA English
DT Article
ID GROWTH; NANOFIBERS; INTEGRATION; REACTOR; DEVICES; ARRAY
AB The bottom-up fabrication and electrical properties of end-to-end contacted multiwalled carbon nanotube (MWCNT) heterojunctions are reported. The vertically aligned MWCNT heterojunction arrays are formed via successive plasma-enhanced chemical vapor deposition processing to achieve the layered junction architecture. Electron microscopy and current-sensing atomic force microscopy are used to reveal the physical nature of the junctions. Symmetric, nonlinear I-V curves of the as-fabricated junctions indicate that a tunnel barrier is formed between the end-to-end contacted MWCNTs. Repeated high bias I-V scans of many devices connected in parallel fuses the heterojunctions, as manifested by a shift to linear I-V characteristics.
C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA.
RP Cassell, AM (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA.
EM jli@mail.arc.nasa.gov
RI Li, Jun/H-7771-2013
OI Li, Jun/0000-0002-3689-8946
NR 19
TC 28
Z9 30
U1 3
U2 12
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0003-6951
J9 APPL PHYS LETT
JI Appl. Phys. Lett.
PD SEP 20
PY 2004
VL 85
IS 12
BP 2364
EP 2366
DI 10.1063/1.1794356
PG 3
WC Physics, Applied
SC Physics
GA 857UW
UT WOS:000224145300070
ER
PT J
AU Strolger, LG
Riess, AG
Dahlen, T
Livio, M
Panagia, N
Challis, P
Tonry, JL
Filippenko, AV
Chornock, R
Ferguson, H
Koekemoer, A
Mobasher, B
Dickinson, M
Giavalisco, M
Casertano, S
Hook, R
Bondin, S
Leibundgut, B
Nonino, M
Rosati, P
Spinrad, H
Steidel, CC
Stern, D
Garnavich, PM
Matheson, T
Grogin, N
Hornschemeier, A
Kretchmer, C
Laidler, VG
Lee, K
Lucas, R
de Mello, D
Moustakas, LA
Ravindranath, S
Richardson, M
Taylor, E
AF Strolger, LG
Riess, AG
Dahlen, T
Livio, M
Panagia, N
Challis, P
Tonry, JL
Filippenko, AV
Chornock, R
Ferguson, H
Koekemoer, A
Mobasher, B
Dickinson, M
Giavalisco, M
Casertano, S
Hook, R
Bondin, S
Leibundgut, B
Nonino, M
Rosati, P
Spinrad, H
Steidel, CC
Stern, D
Garnavich, PM
Matheson, T
Grogin, N
Hornschemeier, A
Kretchmer, C
Laidler, VG
Lee, K
Lucas, R
de Mello, D
Moustakas, LA
Ravindranath, S
Richardson, M
Taylor, E
TI The Hubble Higher z supernova search: Supernovae to z approximate to 1.6
and constraints on type Ia progenitor models
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE supernovae : general; surveys
ID HIGH-REDSHIFT SUPERNOVAE; STAR-FORMATION HISTORY; ACCELERATING UNIVERSE;
SOLAR NEIGHBORHOOD; SPACE-TELESCOPE; ADVANCED CAMERA; WHITE-DWARFS; HOST
GALAXY; DEEP SURVEY; FIELD
AB We present results from the Hubble Higher z Supernova Search, the first space-based open field survey for supernovae (SNe). In cooperation with the Great Observatories Origins Deep Survey, we have used the Hubble Space Telescope with the Advanced Camera for Surveys to cover similar to300 arcmin(2) in the area of the Chandra Deep Field South and the Hubble Deep Field North on five separate search epochs (separated by similar to45 day intervals) to a limiting magnitude of F850LP approximate to 26. These deep observations have allowed us to discover 42 SNe in the redshift range 0.2 < z < 1.6. As these data span a large range in redshift, they are ideal for testing the validity of Type Ia supernova progenitor models with the distribution of expected "delay times,'' from progenitor star formation to Type Ia SN explosion, and the SN rates these models predict. Through a Bayesian maximum likelihood test, we determine which delay-time models best reproduce the redshift distribution of SNe Ia discovered in this survey. We find that models that require a large fraction of "prompt'' (less than 2 Gyr) SNe Ia poorly reproduce the observed redshift distribution and are rejected at greater than 95% confidence. We find that Gaussian models best fit the observed data for mean delay times in the range of 2-4 Gyr.
C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA.
European Space Agcy, ESTEC, Space Telescope Div, NL-2200 AG Noordwijk, Netherlands.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA.
European So Observ, D-85748 Garching, Germany.
Osserv Astron Trieste, INAF, I-34131 Trieste, Italy.
CALTECH, Dept Astron, Pasadena, CA 91125 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Notre Dame, Notre Dame, IN 46556 USA.
Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA.
Space Telescope Sci Inst, Comp Sci Corp, Baltimore, MD 21218 USA.
Univ Melbourne, Sch Phys, Parkville, Vic 3010, Australia.
RP Strolger, LG (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA.
EM strolger@stsci.edu
OI Nonino, Mario/0000-0001-6342-9662; Koekemoer, Anton/0000-0002-6610-2048
NR 69
TC 202
Z9 202
U1 0
U2 4
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 20
PY 2004
VL 613
IS 1
BP 200
EP 223
DI 10.1086/422901
PN 1
PG 24
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856VW
UT WOS:000224074400018
ER
PT J
AU DeLaney, T
Rudnick, L
Fesen, RA
Jones, TW
Petre, R
Morse, JA
AF DeLaney, T
Rudnick, L
Fesen, RA
Jones, TW
Petre, R
Morse, JA
TI Kinematics of X-ray-emitting components in Cassiopeia A
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE ISM : individual (Cassiopeia A); supernova remnants
ID SUPERNOVA REMNANT CASSIOPEIA; PARTICLE-ACCELERATION; EXPANSION; EJECTA;
EMISSION; EVOLUTION; EXPLOSION; CHANDRA; SHOCKS
AB We present high-resolution X-ray proper-motion measurements of Cassiopeia A using Chandra X-Ray Observatory observations from 2000 and 2002. We separate the emission into four spectrally distinct classes: Si-dominated, Fe-dominated, low-energy-enhanced, and continuum-dominated. These classes also represent distinct spatial and kinematic components. The Si- and Fe-dominated classes are ejecta and have a mean expansion rate of 0.2% yr(-1). This is the same as for the forward shock filaments but less than the 0.3% yr(-1) characteristic of optical ejecta. The low-energy-enhanced spectral class possibly illuminates a clumpy circumstellar component and has a mean expansion rate of 0.05% yr(-1). The continuum-dominated emission likely represents the forward shock and consists of diffuse circumstellar material, which is seen as a circular ring around the periphery of the remnant as well as projected across the center.
C1 Univ Minnesota, Dept Astron, Minneapolis, MN 55455 USA.
Dartmouth Coll, Dept Phys & Astron, Hanover, NH 03755 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA.
RP DeLaney, T (reprint author), Univ Minnesota, Dept Astron, 116 Church St SE, Minneapolis, MN 55455 USA.
EM tdelaney@astro.umn.edu; larry@astro.umn.edu; fesen@snr.dartmouth.edu;
twj@astro.umn.edu; petre@lheavx.gsfc.nasa.gov; Jon.Morse@asu.edu
OI DeLaney, Tracey/0000-0002-0338-296X
NR 33
TC 32
Z9 32
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 20
PY 2004
VL 613
IS 1
BP 343
EP 348
DI 10.1086/422906
PN 1
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856VW
UT WOS:000224074400028
ER
PT J
AU Corcoran, MF
Hamaguchi, K
Gull, T
Davidson, K
Petre, R
Hillier, DJ
Smith, N
Damineli, A
Morse, JA
Walborn, NR
Verner, E
Collins, N
White, S
Pittard, JM
Weis, K
Bomans, D
Butt, Y
AF Corcoran, MF
Hamaguchi, K
Gull, T
Davidson, K
Petre, R
Hillier, DJ
Smith, N
Damineli, A
Morse, JA
Walborn, NR
Verner, E
Collins, N
White, S
Pittard, JM
Weis, K
Bomans, D
Butt, Y
TI Waiting in the wings: Reflected X-ray emission from the Homunculus
nebula
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE circumstellar matter; ISM : individual (Homunculus nebula); reflection
nebulae; stars : individual (eta Carinae); X-rays : stars
ID ETA-CARINAE; BINARY HYPOTHESIS; LIGHT-CURVE; CHANDRA; SPECTROMETER;
ENERGY; ORBIT; MASS
AB We report the first detection of X-ray emission associated with the Homunculus nebula that surrounds the supermassive star eta Car. The emission is characterized by a temperature in excess of 100 MK and is consistent with scattering of the time-delayed X-ray flux associated with the star. The nebular emission is bright in the northwestern lobe and near the central regions of the Homunculus, and fainter in the southeastern lobe. We also report the detection of an unusually broad Fe K fluorescent line, which may indicate fluorescent scattering off the wind of a companion star or some other high-velocity outflow. The X-ray Homunculus is the nearest member of the small class of Galactic X-ray reflection nebulae, and the only one in which both the emitting and reflecting sources are distinguishable.
C1 Univ Space Res Assoc, Seabrook, MD 20706 USA.
NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
CNR, Washington, DC 20001 USA.
NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA.
Univ Minnesota, Dept Astron, Minneapolis, MN 55455 USA.
Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA.
Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA.
Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfericas, BR-05508900 Sao Paulo, Brazil.
Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA.
Space Telescope Sci Inst, Baltimore, MD 21218 USA.
Catholic Univ Amer, Dept Phys, IACS, Washington, DC 20064 USA.
Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
Univ Leeds, Sch Phys & Astron, Leeds LS2 9JT, W Yorkshire, England.
Ruhr Univ Bochum, Inst Astron, D-44780 Bochum, Germany.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
RP Corcoran, MF (reprint author), Univ Space Res Assoc, 7501 Forbes Blvd,Suite 206, Seabrook, MD 20706 USA.
EM corcoran@lheapop.gsfc.nasa.gov; kenji@milkyway.gsfc.nasa.gov;
gull@sea.gsfc.nasa.gov; kd@astro.umn.edu; JDH@galah.phyast.pitt.edu;
nathans@ozma.colorado.edu; damineli@astro.iag.usp.br; jon.morse@asu.edu;
walborn@stsci.edu; kverner@fe2.gsfc.nasa.gov;
collins@zolo.gsfc.nasa.gov; white@astro.umd.edu; jmp@ast.leeds.ac.uk;
kweis@astro.rub.de; bomans@astro.ruhr-uni-bochum.de;
ybutt@head-cfa.harvard.edu
RI Damineli, Augusto/D-8210-2012; Gull, Theodore/D-2753-2012;
OI Damineli, Augusto/0000-0002-7978-2994; Gull,
Theodore/0000-0002-6851-5380; Pittard, Julian/0000-0003-2244-5070
NR 31
TC 29
Z9 29
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 20
PY 2004
VL 613
IS 1
BP 381
EP 386
DI 10.1086/423024
PN 1
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856VW
UT WOS:000224074400032
ER
PT J
AU Gorti, U
Hollenbach, D
AF Gorti, U
Hollenbach, D
TI Models of chemistry, thermal balance, and infrared spectra from
intermediate-aged disks around G and K stars
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE circumstellar matter; infrared : general; planetary systems :
protoplanetary disks; stars : formation
ID T-TAURI STARS; MAIN-SEQUENCE STARS; PHOTOIONIZATION CROSS-SECTIONS;
HERBIG AE STARS; CIRCUMSTELLAR DISKS; MOLECULAR-HYDROGEN; ACCRETION
DISKS; GAS DISK; PROTOPLANETARY DISKS; INTERSTELLAR-MEDIUM
AB We model gas and dust emission from regions 0.3-20 AU from a central low-mass star in intermediate-aged (similar to10(7) yr) disks whose dust is fairly optically thin to stellar radiation. The models treat thermal balance and chemistry self-consistently and calculate the vertical density and temperature structure of the gas in a disk. The gas and dust temperatures are calculated separately. The models cover gas masses 10(-3) to 1 M-J and dust masses 10(-7) to 10(-4) M-J and treat solar-type (G and K) stars. We focus on mid-infrared and far-infrared emission lines from various gas species such as the rotational lines of H-2, OH, H2O, and CO molecules and the fine-structure lines of carbon, oxygen, sulfur, iron, and silicon atoms and ions. These lines and the dust continuum are observable by the Spitzer Space Telescope and future missions including SOFIA and the Herschel Space Observatory. We find that the [S I] 25.23 mum line is the strongest emission line for a wide range of disk and stellar parameters, followed by emission from [Si II] 34.8 mum, [Fe II] 26 mum, and [O I] 63 mum. [Fe I] 24 mum and rotational lines of OH and H2O are strong when gas masses are high (greater than or similar to0.1 M-J). Emission from the rotational lines of H-2 is more difficult to detect unless disk gas masses are substantial (greater than or similar to0.1 M-J). For emission from H-2 lines to be observable and yet for the dust to be optically thin in stellar light, the ratio of gas to small submillimeter-sized dust particle mass in the disk needs to be greater than or similar to1000, or at least an order of magnitude higher than that in the interstellar medium. This may be possible at intermediate stages in disk evolution, such as in the gas-gathering stage of the core accretion scenario for giant planet formation, in which most of the dust has coagulated into larger objects ( much greater than1 mm) but the gas has not yet fully dispersed. Whereas the absolute fluxes observed in some lines such as [Fe I] 24 mum and H-2 S(0) 28 mum primarily measure the gas mass in the disks, various line ratios diagnose the inner radius of the gas and the radial temperature and surface density distribution of the gas. Many lines become optically thick and/or suffer chemical or thermal effects such that the line luminosities do not increase appreciably with increasing gas mass. We predict that it may be difficult for the Spitzer Space Telescope to detect less than or similar to1 M-J of gas in optically thin (in dust) disks at distances greater than or similar to150 pc. The models presented here will be useful in future infrared studies of the timescale for the dispersion of gas in a planet-forming disk and tests of core accretion models of giant planet formation.
C1 Univ Calif Berkeley, Dept Phys & Astron, Berkeley, CA 94720 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Gorti, U (reprint author), Univ Calif Berkeley, Dept Phys & Astron, Berkeley, CA 94720 USA.
NR 81
TC 82
Z9 82
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 20
PY 2004
VL 613
IS 1
BP 424
EP 447
DI 10.1086/422406
PN 1
PG 24
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856VW
UT WOS:000224074400036
ER
PT J
AU Band, DL
Norris, JP
Bonnell, JT
AF Band, DL
Norris, JP
Bonnell, JT
TI Gamma-ray burst intensity distributions
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE gamma rays : bursts
ID STANDARD ENERGY RESERVOIR; LUMINOSITY; REDSHIFTS
AB We use the lag-luminosity relation to calculate self-consistently the redshifts, apparent peak bolometric luminosities L-B, and isotropic energies E-iso for a large sample of BATSE gamma-ray bursts. We consider two different forms of the lag-luminosity relation; for both forms the median redshift for our burst database is 1.6. We model the resulting E-iso sample with power-law and Gaussian probability distributions without redshift evolution, both of which are reasonable models. The power-law model has an index of alpha(E) 1.76 +/- 0.05 (95% confidence), where p(E-iso) proportional to E-iso(-alphaE) The simple universal jet profile model suggested but did not require alpha(E) = 2, and subsequent physically reasonable refinements to this model permit greater diversity in alpha(E), as well as deviations from a power law; therefore, our observed E-iso probability distribution does not disprove the universal jet model.
C1 NASA, Goddard Space Flight Ctr, GLAST Sci Support Ctr, Greenbelt, MD 20771 USA.
RP Band, DL (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Astrophys, 1000 Hilltop Circle, Baltimore, MD 21250 USA.
EM dband@lheapop.gsfc.nasa.gov; jnorris@lheapop.gsfc.nasa.gov;
jerry@milkyway.gsfc.nasa.gov
NR 19
TC 32
Z9 33
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 20
PY 2004
VL 613
IS 1
BP 484
EP 491
DI 10.1086/422869
PN 1
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856VW
UT WOS:000224074400040
ER
PT J
AU Brosius, JW
Phillips, KJH
AF Brosius, JW
Phillips, KJH
TI Extreme-ultraviolet and X-ray spectroscopy of a solar flare loop
observed at high time resolution: A case study in chromospheric
evaporation
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE Sun : activity; Sun : corona; Sun : flares; Sun : X-rays, gamma rays;
Sun : UV radiation
ID CORONAL DIAGNOSTIC SPECTROMETER; BRAGG CRYSTAL SPECTROMETER; RADIATIVE
HYDRODYNAMICS; IMPULSIVE PHASE; MAXIMUM MISSION; ATOMIC DATABASE;
EMISSION-LINES; A MISSION; TELESCOPE; DYNAMICS
AB We present extreme-ultraviolet (EUV) and X-ray light curves and Doppler velocity measurements for a GOES class M2 solar flare observed in NOAA Active Region 9433 on 2001 April 24 at high time resolution with the Coronal Diagnostic Spectrometer (CDS) on board the Solar and Heliospheric Observatory (SOHO) satellite (9.83 s) and the Bragg Crystal Spectrometer (BCS) and Hard X-Ray Telescope (HXT) on board the Yohkoh satellite (9.00 s). Coordinated imagery with SOHO's Extreme-ultraviolet Imaging Telescope and the Transition Region and Coronal Explorer satellite reveal that the CDS slit was centered on the flare commencement site; coordinated magnetograms from SOHO's Michelson Doppler Imager are consistent with this site being the footpoint of a flare loop anchored in positive magnetic field near the outer edge of a sunspot's penumbra. CDS observations include the preflare quiescent phase, two precursors, the flare impulsive and peak phases, and its slow decline. We find that (1) the average wavelengths of O III, O IV, O V, Ne VI, and He II lines measured during the preflare quiescent phase are equal ( within the measurement uncertainties) to those measured during the late decline phase, indicating that they can be used as reference standards against which to measure Doppler velocities during the flare; (2) the EUV lines of O III, O IV, O V, and He II exhibit upflow velocities of similar to40 km s(-1) during both precursor events, suggestive of small-scale chromospheric evaporation; ( 3) the Fe XIX EUV intensity rises and stays above its preflare noise level during the second ( later) precursor; ( 4) the maximum upflow velocities measured in Fe XIX with CDS (64 km s(-1)) and in Ca XIX (65 km s(-1)) and S XV (78 km s(-1)) with BCS occur during the flare impulsive phase and are simultaneous within the instrumental time resolutions; ( 5) the Fe XIX EUV intensity begins its impulsive rise nearly 90 s later than the rise in intensities of the cooler lines; ( 6) hard X-ray emission arises nearly 60 s after the cool EUV lines begin their impulsive intensity rise; and ( 7) the EUV lines of O III, O IV, O V, and He II exhibit downflow velocities of similar to40 km s(-1) during the flare impulsive phase, suggesting momentum balance between the hot upflowing material and the cool downflowing material. Our observations are consistent with energy transport by nonthermal particle beams in chromospheric evaporation theory.
C1 Catholic Univ Amer, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Brosius, JW (reprint author), Catholic Univ Amer, NASA, Goddard Space Flight Ctr, Code 682, Greenbelt, MD 20771 USA.
NR 41
TC 69
Z9 70
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 20
PY 2004
VL 613
IS 1
BP 580
EP 591
DI 10.1086/422873
PN 1
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856VW
UT WOS:000224074400050
ER
PT J
AU Hollis, JM
Jewell, PR
Lovas, FJ
Remijan, A
AF Hollis, JM
Jewell, PR
Lovas, FJ
Remijan, A
TI Green Bank Telescope observations of interstellar glycolaldehyde:
Low-temperature sugar
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE ISM : abundances; ISM : clouds; ISM : individual (Sagittarius
B2(N-LMH)); ISM : molecules; radio lines : ISM
ID GALACTIC-CENTER; SGR B2; CALIBRATION; ABSORPTION; AMMONIA
AB Interstellar glycolaldehyde (CH2OHCHO) has been detected with the 100 m Green Bank Telescope (GBT) toward the star-forming region Sagittarius B2(N) by means of the 1(10)-1(01), 2(11)-2(02), 3(12)-3(03), and 4(13)-4(04) rotational transitions at 13.48, 15.18, 17.98, and 22.14 GHz, respectively. An analysis of these four high signal-to-noise ratio rotational transitions yields a glycolaldehyde state temperature of similar to8 K. Previously reported emission-line detections of glycolaldehyde with the NRAO 12 m telescope at millimeter wavelengths (71-103 GHz) are characterized by a state temperature of similar to50 K. By comparison, the GBT detections are surprisingly strong and are seen in emission at 13.48 GHz, emission and absorption at 15.18 GHz, and absorption at 17.98 and 22.14 GHz. We attribute the strong absorption observed by the GBT at the higher frequencies to the correspondingly smaller GBT beams coupling better to the continuum source(s) in Sagittarius B2(N). A possible model for the two-temperature regions of glycolaldehyde is discussed.
C1 NASA, Goddard Space Flight Ctr, Space & Earth Data Comp Div, Greenbelt, MD 20771 USA.
Natl Radio Astron Observ, Green Bank, WV 24944 USA.
Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD 20899 USA.
RP Hollis, JM (reprint author), NASA, Goddard Space Flight Ctr, Space & Earth Data Comp Div, Code 930, Greenbelt, MD 20771 USA.
NR 16
TC 73
Z9 73
U1 0
U2 6
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 20
PY 2004
VL 613
IS 1
BP L45
EP L48
DI 10.1086/424927
PN 2
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856VZ
UT WOS:000224074700012
ER
PT J
AU Gao, BC
Chan, PK
Li, RR
AF Gao, BC
Chan, PK
Li, RR
TI A global water vapor data set obtained by merging the SSMI and MODIS
data
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID PRECIPITABLE WATER; OCEAN ALGORITHM; TEMPERATURE; RETRIEVALS; CLOUDS
AB At present, the column amount of atmospheric water vapor over clear land surfaces and over oceanic areas with sun glint is operationally retrieved from radiances measured with near-IR channels of the Moderate Resolution Imaging SpectroRadiometer (MODIS) instruments on board the NASA Terra and Aqua Spacecraft platforms. TPW over oceans has also been derived operationally from radiances measured by the Special Sensor Microwave Imagers (SSMI) on board different spacecraft. We report in this letter that a global water vapor data product with improved quality can be obtained by merging the monthly-mean MODIS near-IR TPW data over land and the SSMI TPW data over water surfaces. Major characteristics of the seasonal variations of TPW are described. Examples of water vapor anomalies associated with the 2002 El Nino event are presented. We expect that the merged TPW data product will have useful applications for the study of the global hydrological cycle.
C1 USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA.
NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA.
Syst Sci & Applicat Inc, Lanham, MD USA.
Univ Maryland Baltimore Cty, Baltimore, MD 21228 USA.
RP Gao, BC (reprint author), USN, Res Lab, Remote Sensing Div, Code 7232,4555 Overlook Ave SW, Washington, DC 20375 USA.
EM gao@nrl.navy.mil
NR 13
TC 7
Z9 7
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD SEP 18
PY 2004
VL 31
IS 18
AR L18103
DI 10.1029/2004GL020656
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 857NC
UT WOS:000224123100005
ER
PT J
AU Ray, EA
Rosenlof, KH
Richard, EC
Hudson, PK
Cziczo, DJ
Loewenstein, M
Jost, HJ
Lopez, J
Ridley, B
Weinheimer, A
Montzka, D
Knapp, D
Wofsy, SC
Daube, BC
Gerbig, C
Xueref, I
Herman, RL
AF Ray, EA
Rosenlof, KH
Richard, EC
Hudson, PK
Cziczo, DJ
Loewenstein, M
Jost, HJ
Lopez, J
Ridley, B
Weinheimer, A
Montzka, D
Knapp, D
Wofsy, SC
Daube, BC
Gerbig, C
Xueref, I
Herman, RL
TI Evidence of the effect of summertime midlatitude convection on the
subtropical lower stratosphere from CRYSTAL-FACE tracer measurements
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE convection; mixing; stratosphere
ID IN-SITU MEASUREMENTS; FOREST-FIRE SMOKE; WATER-VAPOR; DEEP CONVECTION;
TRANSPORT; TROPOSPHERE; PLUMES; OZONE; TROPOPAUSE; LAYER
AB [1] Trace gas and particle measurements taken during the CRYSTAL-FACE mission are used to examine mixing in the summer subtropical lower stratosphere. Vigorous convection in the central and eastern United States injected a significant amount of tropospheric air into the lower stratosphere, which was subsequently advected over the region sampled during the CRYSTAL-FACE mission. Aerosols produced by biomass burning were observed over Florida during a time period with a large number of forest fires in the western United States and eastern Canada, providing evidence of convective injection of tropospheric air into the lower stratosphere. The circumstances of the large-scale flow pattern in the upper troposphere and lower stratosphere, vigorous summertime convection, abundant forest fires, and the downstream sampling allow a unique view of mixing in the lower stratosphere. We calculate the fractions of midlatitude tropospheric air in the sampled lower stratosphere and mixing rates on the basis of consistency between a number of tracer-tracer correlations. The tropospheric endpoints to the mixing estimates give an indication of midlatitude continental convective input into the lower stratosphere. We also discuss the possible impact of summertime midlatitude convection on the composition of the stratosphere as a whole.
C1 NOAA, Aeron Lab, Boulder, CO 80305 USA.
Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Natl Ctr Atmospher Res, Boulder, CO 80307 USA.
Harvard Univ, Dept Atmospher Sci, Cambridge, MA 02138 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP NOAA, Aeron Lab, MS R-AL6,325 Broadway, Boulder, CO 80305 USA.
EM eray@al.noaa.gov
RI Herman, Robert/H-9389-2012; Ray, Eric/D-5941-2013; Gerbig,
Christoph/L-3532-2013; Rosenlof, Karen/B-5652-2008
OI Herman, Robert/0000-0001-7063-6424; Ray, Eric/0000-0001-8727-9849;
Gerbig, Christoph/0000-0002-1112-8603; Rosenlof,
Karen/0000-0002-0903-8270
NR 38
TC 25
Z9 27
U1 2
U2 7
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 18
PY 2004
VL 109
IS D18
AR D18304
DI 10.1029/2004JD004655
PG 13
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 857NH
UT WOS:000224123700003
ER
PT J
AU Suntharalingam, P
Jacob, DJ
Palmer, PI
Logan, JA
Yantosca, RM
Xiao, YP
Evans, MJ
Streets, DG
Vay, SL
Sachse, GW
AF Suntharalingam, P
Jacob, DJ
Palmer, PI
Logan, JA
Yantosca, RM
Xiao, YP
Evans, MJ
Streets, DG
Vay, SL
Sachse, GW
TI Improved quantification of Chinese carbon fluxes using CO2/CO
correlations in Asian outflow
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE regional carbon fluxes; multiple-species correlations; atmospheric; CO2
modeling
ID TRACE-P EXPERIMENT; WESTERN NORTH PACIFIC; ATMOSPHERIC CO2; CHEMICAL
EVOLUTION; CONTINENTAL OUTFLOW; TRANSPORT PATHWAYS; EMISSIONS; SINKS;
MONOXIDE; DIOXIDE
AB [1] We use observed CO2: CO correlations in Asian outflow from the TRACE-P aircraft campaign ( February - April 2001), together with a three-dimensional global chemical transport model (GEOS-CHEM), to constrain specific components of the east Asian CO2 budget including, in particular, Chinese emissions. The CO2/CO emission ratio varies with the source of CO2 ( different combustion types versus the terrestrial biosphere) and provides a characteristic signature of source regions and source type. Observed CO2/CO correlation slopes in east Asian boundary layer outflow display distinct regional signatures ranging from 10 - 20 mol/mol ( outflow from northeast China) to 80 mol/mol ( over Japan). Model simulations using best a priori estimates of regional CO2 and CO sources from Streets et al. [ 2003] ( anthropogenic), the CASA model (biospheric), and Duncan et al. [ 2003] (biomass burning) overestimate CO2 concentrations and CO2/CO slopes in the boundary layer outflow. Constraints from the CO2/CO slopes indicate that this must arise from an overestimate of the modeled regional net biospheric CO2 flux. Our corrected best estimate of the net biospheric source of CO2 from China for March - April 2001 is 3200 Gg C/d, which represents a 45% reduction of the net flux from the CASA model. Previous analyses of the TRACE-P data had found that anthropogenic Chinese CO emissions must be similar to 50% higher than in Streets et al.' s [ 2003] inventory. We find that such an adjustment improves the simulation of the CO2/CO slopes and that it likely represents both an underreporting of sector activity ( domestic and industrial combustion) and an underestimate of CO emission factors. Increases in sector activity would imply increases in Chinese anthropogenic CO2 emissions and would also imply a further reduction of the Chinese biospheric CO2 source to reconcile simulated and observed CO2 concentrations.
C1 Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA.
Argonne Natl Lab, Argonne, IL 60439 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Harvard Univ, Div Engn & Appl Sci, Pierce Hall,29 Oxford St, Cambridge, MA 02138 USA.
EM pns@io.harvard.edu; djj@io.harvard.edu; pip@io.harvard.edu;
jal@io.harvard.edu; bmy@io.harvard.edu; xyp@io.harvard.edu;
mje@io.harvard.edu; dstreets@anl.gov; s.a.vay@larc.nasa.gov;
g.w.sachse@larc.nasa.gov
RI Palmer, Paul/F-7008-2010; Evans, Mathew/A-3886-2012; Yantosca,
Robert/F-7920-2014; Chem, GEOS/C-5595-2014
OI Evans, Mathew/0000-0003-4775-032X; Yantosca, Robert/0000-0003-3781-1870;
NR 57
TC 65
Z9 66
U1 1
U2 18
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 18
PY 2004
VL 109
IS D18
AR D18S18
DI 10.1029/2003JD004362
PG 13
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 857NH
UT WOS:000224123700001
ER
PT J
AU Martin, S
Polyakov, I
Markus, T
Drucker, R
AF Martin, S
Polyakov, I
Markus, T
Drucker, R
TI Okhotsk Sea Kashevarov Bank polynya: Its dependence on diurnal and
fortnightly tides and its initial formation
SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
LA English
DT Article
DE Kashevarov Bank; Okhotsk Sea; polynyas
ID SATELLITE PASSIVE MICROWAVE; ICE EDGE; IMAGERY; FRAZIL; OCEAN
AB [1] A powerful resonance in the O1 and K1 diurnal tides occurs over the Kashevarov Bank in the Okhotsk Sea. Model studies show that this resonance creates tidal mixing and an associated vertical heat flux, both with diurnal and fortnightly components. In midwinter this flux controls the behavior of the resultant polynya; in early winter it affects the polynya formation. For the midwinter case, examination of numerical results and of imagery derived from the Special Sensor Microwave Imager (SSM/I), the advanced very high resolution radiometer (AVHRR), and the RADARSAT ScanSAR shows that the polynya area varies diurnally and fortnightly. Specifically, for the 2000 and 2001 winters, daily averaged passive microwave images clearly show a fortnightly cycle in the polynya area. At the diurnal period the model shows that the location of the maximum heat flux oscillates between the northwestern and southwestern edge of the bank and that the polynya oscillates between the western edge of the bank and being elongated in the east-west direction over the southern edge. Passive microwave swath and AVHRR imagery show a similar polynya behavior. For the early winter case and during a period of northerly winds, synthetic aperture radar imagery shows that the polynya consists of two parts, an upwelling polynya over the bank and a secondary polynya downwind of the bank with properties similar to coastal polynyas. In the case of the secondary polynya the region of upwelled warm water over the bank serves as its northern boundary.
C1 Univ Washington, Sch Oceanog, Seattle, WA 98195 USA.
NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA.
Univ Alaska Fairbanks, Int Arctic Res Ctr, Fairbanks, AK 99775 USA.
RP Martin, S (reprint author), Univ Washington, Sch Oceanog, Box 357940, Seattle, WA 98195 USA.
EM seelye@ocean.washington.edu
RI Markus, Thorsten/D-5365-2012
NR 15
TC 12
Z9 12
U1 0
U2 1
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9275
EI 2169-9291
J9 J GEOPHYS RES-OCEANS
JI J. Geophys. Res.-Oceans
PD SEP 18
PY 2004
VL 109
IS C9
AR C09S04
DI 10.1029/2003JC002215
PG 16
WC Oceanography
SC Oceanography
GA 857NO
UT WOS:000224124400002
ER
PT J
AU Beirle, S
Platt, U
von Glasow, R
Wenig, M
Wagner, T
AF Beirle, S
Platt, U
von Glasow, R
Wenig, M
Wagner, T
TI Estimate of nitrogen oxide emissions from shipping by satellite remote
sensing
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID MARINE BOUNDARY-LAYER; GOME MEASUREMENTS; IMPACT; SHIPS
AB In recent years, the role of ship emissions has attracted increasing attention. Recent inventories estimate that they contribute significantly to anthropogenic emissions of nitrogen oxides, with a large impact on composition and chemistry of the marine boundary layer. Nevertheless, the number of observational studies is still rather small. Here we present the first detection of ship tracks in NO2 maps derived from satellite data. We have used the congested track connecting Sri Lanka to Indonesia to estimate the corresponding ship emissions of nitrogen oxides to 23 (10-73) Gg[N]/yr. In addition, we were able to derive the mean lifetime of boundary layer NOx to be 3.7 (1.9-6.0) hours in the respective region. Our estimates are in good agreement with ship emission inventories (about 22-54 Gg[N]/yr) as well as the short lifetimes (of down to 2 hours at daytime) as recently modeled for ship plumes.
C1 Univ Heidelberg, Inst Umweltphys, D-69120 Heidelberg, Germany.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Beirle, S (reprint author), Univ Heidelberg, Inst Umweltphys, INF 229, D-69120 Heidelberg, Germany.
EM beirle@iup.uni-heidelberg.de
RI von Glasow, Roland/E-2125-2011; Wenig, Mark/K-7279-2012
OI von Glasow, Roland/0000-0002-3944-2784;
NR 26
TC 72
Z9 74
U1 3
U2 14
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD SEP 17
PY 2004
VL 31
IS 18
AR L18102
DI 10.1029/2004GL020312
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 857NB
UT WOS:000224123000001
ER
PT J
AU Quinn, PK
Coffman, DJ
Bates, TS
Welton, EJ
Covert, DS
Miller, TL
Johnson, JE
Maria, S
Russell, L
Arimoto, R
Carrico, CM
Rood, MJ
Anderson, J
AF Quinn, PK
Coffman, DJ
Bates, TS
Welton, EJ
Covert, DS
Miller, TL
Johnson, JE
Maria, S
Russell, L
Arimoto, R
Carrico, CM
Rood, MJ
Anderson, J
TI Aerosol optical properties measured on board the Ronald H. Brown during
ACE-Asia as a function of aerosol chemical composition and source region
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE aerosol optical properties; aerosol chemical composition; ACE-Asia
ID AERODYNAMIC PARTICLE SIZER; MARINE BOUNDARY-LAYER; RADIATIVE PROPERTIES;
ELEMENTAL CARBON; REFRACTIVE-INDEX; LIGHT-ABSORPTION; UNITED-STATES;
URBAN AEROSOL; BLACK CARBON; INDOEX 1999
AB During the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia) intensive field campaign conducted in the spring of 2001, aerosol properties were measured on board the R/V Ronald H. Brown to study the effects of the Asian aerosol on atmospheric chemistry and climate in downwind regions. Aerosol properties measured in the marine boundary layer included chemical composition; number size distribution; and light scattering, hemispheric backscattering, and absorption coefficients. In addition, optical depth and vertical profiles of aerosol 180degrees backscatter were measured. Aerosol within the ACE-Asia study region was found to be a complex mixture resulting from marine, pollution, volcanic, and dust sources. Presented here as a function of air mass source region are the mass fractions of the dominant aerosol chemical components, the fraction of the scattering measured at the surface due to each component, mass scattering efficiencies of the individual components, aerosol scattering and absorption coefficients, single scattering albedo, Angstrorm exponents, optical depth, and vertical profiles of aerosol extinction. All results, except aerosol optical depth and the vertical profiles of aerosol extinction, are reported at a relative humidity of 55+/-5%. An overdetermined data set was collected so that measured and calculated aerosol properties could be compared, internal consistency in the data set could be assessed, and sources of uncertainty could be identified. By adjusting the measured size distribution to take into account nonsphericity of the dust aerosol, calculated and measured aerosol mass and scattering coefficients agreed within overall experimental uncertainties. Differences between measured and calculated aerosol absorption coefficients were not within reasonable uncertainty limits, however, and may indicate the inability of Mie theory and the assumption of internally mixed homogeneous spheres to predict absorption by the ACE-Asia aerosol. Mass scattering efficiencies of non-sea-salt sulfate aerosol, sea salt, submicron particulate organic matter, and dust found for the ACE-Asia aerosol are comparable to values estimated for ACE 1, Aerosols99, and the Indian Ocean Experiment (INDOEX). Unique to the ACE-Asia aerosol were the large mass fractions of dust, the dominance of dust in controlling the aerosol optical properties, and the interaction of dust with soot aerosol.
C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA.
Univ Washington, Joint Inst Study Atmosphere & Ocean, Seattle, WA 98195 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA.
Carlsbad Environm Monitoring & Res Ctr, Carlsbad, NM 88220 USA.
Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA.
Univ Illinois, Dept Civil & Environm Engn, Urbana, IL 61801 USA.
Arizona State Univ, Dept Mech & Aerosp Engn, Tempe, AZ 85287 USA.
RP Quinn, PK (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA.
EM patricia.k.quinn@noaa.gov
RI Welton, Ellsworth/A-8362-2012; Bates, Timothy/L-6080-2016; Quinn,
Patricia/R-1493-2016
OI Quinn, Patricia/0000-0003-0337-4895
NR 66
TC 78
Z9 86
U1 4
U2 25
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 17
PY 2004
VL 109
IS D19
AR D19S01
DI 10.1029/2003JD004010
PG 28
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 857NJ
UT WOS:000224123900001
ER
PT J
AU Beacom, JF
Bell, NF
Dodelson, S
AF Beacom, JF
Bell, NF
Dodelson, S
TI Neutrinoless universe
SO PHYSICAL REVIEW LETTERS
LA English
DT Article
ID TRITIUM BETA-SPECTRUM; LONG-RANGE FORCES; FLAVOR OSCILLATIONS;
DARK-MATTER; MAJORON MODEL; DECAY; MASS; ASYMMETRY; LIGHT; WMAP
AB We consider the consequences for the relic neutrino abundance if extra neutrino interactions are allowed, e.g., the coupling of neutrinos to a light (compared to m(nu)) boson. For a wide range of couplings not excluded by other considerations, the relic neutrinos would annihilate to bosons at late times and thus make a negligible contribution to the matter density today. This mechanism evades the neutrino mass limits arising from large scale structure.
C1 Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA.
Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA.
RP Beacom, JF (reprint author), Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, POB 500, Batavia, IL 60510 USA.
OI Beacom, John/0000-0002-0005-2631
NR 62
TC 71
Z9 71
U1 0
U2 0
PU AMERICAN PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 0031-9007
J9 PHYS REV LETT
JI Phys. Rev. Lett.
PD SEP 17
PY 2004
VL 93
IS 12
AR 121302
DI 10.1103/PhysRevLett.93.121302
PG 4
WC Physics, Multidisciplinary
SC Physics
GA 854SO
UT WOS:000223923800018
PM 15447250
ER
PT J
AU Clancy, TC
AF Clancy, TC
TI Multi-scale modeling of polyimides
SO POLYMER
LA English
DT Article
DE Monte Carlo procedure; molecular dynamics; coarse-grained models
ID HIGH-COORDINATION LATTICE; POLYETHYLENE CHAINS; SIMULATION; POLYMERS;
DYNAMICS; MELT
AB A coarse-grained model for a set of three polyimide isomers is developed. Each polyimide is comprised of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and one of three APB isomers: 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene or 1,3-bis(3-aminophenoxy)benzene. The coarse-grained model is constructed as a series of linked vectors following the contour of the polymer backbone. Beads located at the midpoint of each vector define centers for long range interaction energies between monomer subunits. A bulk simulation of each coarse-grained polyimide model is performed with a dynamic Monte Carlo procedure. These coarse-grained models are then reverse-mapped to fully atomistic models. The coarse-grained models show the expected trends in decreasing chain dimensions with increasing meta linkage in the APB section of the repeat unit, although these differences were minor due to the relatively short chains simulated here. Considerable differences are seen among the dynamic Monte Carlo properties of the three polyimide isomers. Decreasing relaxation times are seen with increasing meta linkage in the APB section of the repeat unit. The packing behavior of the three isomers is compared with the atomistic and coarse-grained models. (C) 2004 Elsevier Ltd. All rights reserved.
C1 Natl Inst Aerosp, Hampton, VA 23666 USA.
RP Clancy, TC (reprint author), NASA, Langley Res Ctr, Mail Stop 188E,2 W Reid St, Hampton, VA 23681 USA.
EM t.c.clancy@larc.nasa.gov
NR 25
TC 21
Z9 22
U1 2
U2 14
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0032-3861
J9 POLYMER
JI Polymer
PD SEP 16
PY 2004
VL 45
IS 20
BP 7001
EP 7010
DI 10.1016/j.polymer.2004.08.009
PG 10
WC Polymer Science
SC Polymer Science
GA 855WM
UT WOS:000224005600026
ER
PT J
AU Korotchkina, LG
Ciszak, EM
Patel, MS
AF Korotchkina, LG
Ciszak, EM
Patel, MS
TI Function of several critical amino acids in human pyruvate dehydrogenase
revealed by its structure
SO ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
LA English
DT Article
DE pyruvate dehydrogenase; thiamin pyrophosphate; three-dimensional
structure; function of amino acid residues
ID DIPHOSPHATE DEPENDENT ENZYME; PIGEON BREAST MUSCLE; THIAMIN DIPHOSPHATE;
ACTIVE-SITE; ALPHA-SUBUNIT; COMPLEX DEFICIENCY; ZYMOMONAS-MOBILIS;
LACTIC-ACIDOSIS; BINDING-SITE; MUTATIONS
AB Pyruvate dehydrogenase (E1), an alpha(2)beta(2)(A tetramer, catalyzes the oxidative decarboxylation of pyruvate and reductive acetylation of lipoyl moieties of the dihydrolipoamide acetyltransferase. The roles of betaW135, RIM, alphaM181, alphaH15, and alphaR349 of E1 determined by kinetic analysis were reassessed by analyzing the three-dimensional structure of human E1. The residues identified above are found to play a structural role rather than being directly involved in catalysis: betaW135 is in the center of the hydrophobic interaction between P and beta' subunits; alphaP188 and alphaM181 are critical for the conformation of the TPP-binding motif and interaction between alpha and beta subunits; alphaH15 is necessary for the organization of the N-terminus of a and alpha' subunits; and aR349 supports the interaction of the C-terminus of the alpha subunits with the P subunits. Analysis of several critical E1 residues confirms the importance of residues distant from the active site for subunit interactions and enzyme function. (C) 2004 Elsevier Inc. All rights reserved.
C1 SUNY Buffalo, Dept Biochem, Sch Med & Biomed Sci, Buffalo, NY 14214 USA.
NASA, George C Marshall Space Flight Ctr, Biol & Phys Space Res Lab, Huntsville, AL 35812 USA.
Univ Alabama, Struct Biol Lab, Huntsville, AL 35812 USA.
RP Patel, MS (reprint author), SUNY Buffalo, Dept Biochem, Sch Med & Biomed Sci, Buffalo, NY 14214 USA.
EM mspatel@buffalo.edu
FU NIDDK NIH HHS [DK20478]
NR 44
TC 11
Z9 11
U1 2
U2 5
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0003-9861
J9 ARCH BIOCHEM BIOPHYS
JI Arch. Biochem. Biophys.
PD SEP 15
PY 2004
VL 429
IS 2
BP 171
EP 179
DI 10.1016/j.abb.2004.06.027
PG 9
WC Biochemistry & Molecular Biology; Biophysics
SC Biochemistry & Molecular Biology; Biophysics
GA 849TK
UT WOS:000223563600007
PM 15313220
ER
PT J
AU Kelley, MC
Wong, VK
Hajj, GA
Mannucci, AJ
AF Kelley, MC
Wong, VK
Hajj, GA
Mannucci, AJ
TI On measuring the off-equatorial conductivity before and during
convective ionospheric storms
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID GPS/MET RADIO OCCULTATION; GLOBAL POSITIONING SYSTEM; ELECTRON-DENSITY
AB One of the biggest unknowns in the CIS/ESF ( Convective Ionospheric Storms/Equatorial Spread F) Space Weather problem now can be measured. Radio occultations of the GPS constellation will be measurable on a regular basis during the COSMIC ( Constellation Observing System for Meteorology, Ionosphere and Climate) and C/NOFS (Communications/Navigation Outage Forecast System) satellite era. These measurements can be used to determine the plasma density versus height and hence, the off-equatorial height-integrated conductivity.
C1 Cornell Univ, Sch Elect & Comp Engn, Ithaca, NY 14853 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Kelley, MC (reprint author), Cornell Univ, Sch Elect & Comp Engn, Rhodes Hall, Ithaca, NY 14853 USA.
EM mikek@ece.cornell.edu
RI Mannucci, Anthony/A-1349-2007
OI Mannucci, Anthony/0000-0003-2391-8490
NR 12
TC 6
Z9 6
U1 0
U2 0
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD SEP 15
PY 2004
VL 31
IS 17
AR L17805
DI 10.1029/2004GL020423
PG 3
WC Geosciences, Multidisciplinary
SC Geology
GA 857MZ
UT WOS:000224122800003
ER
PT J
AU Motayed, A
Sharma, A
Jones, KA
Derenge, MA
Iliadis, AA
Mohammad, SN
AF Motayed, A
Sharma, A
Jones, KA
Derenge, MA
Iliadis, AA
Mohammad, SN
TI Electrical characteristics of AlxGa1-xN Schottky diodes prepared by a
two-step surface treatment
SO JOURNAL OF APPLIED PHYSICS
LA English
DT Article
ID OHMIC CONTACT FORMATION; MOLECULAR-BEAM EPITAXY; DRY-ETCH DAMAGE; N-TYPE
GAN; P-TYPE GAN; BARRIER HEIGHT; GALLIUM NITRIDE; DEPENDENCE; ALGAN;
AL(X)GA1-XN
AB Near-ideal Schottky barrier contacts to n-type Al0.22Ga0.78N have been developed by a two-step surface treatment technique. Plasma etching of the AlxGa1-xN surface prior to Schottky metal deposition, combined with sequential chemical treatment of the etched surface, holds promise for developing high quality low-leakage Schottky contacts for low noise applications and for recessed gate high electron mobility transistors. In this work, the effect of postetch chemical treatment of the n-type Al0.22Ga0.78N surface on the performance of the Ni/Au based Schottky contact has been investigated. Three different types of chemical treatment: viz, reactive ion etching, reactive ion etching plus dipping in hot aqua regia, and reactive ion etching plus dipping in hot KOH, are studied. Detailed current-voltage studies of three different surface treated diodes and a comparison with as-deposited diodes reveal significant improvement in the diode characteristics. The latter surface treatment yields Ni/Au Schottky diodes with very low reverse leakage currents, breakdown voltages greater than 44 V, and an ideality factor as low as 1.14. (C) 2004 American Institute of Physics.
C1 Howard Univ, Dept Elect Engn, Washington, DC 20059 USA.
NASA, Goddard Space Flight Ctr, Component Technol & Radiat Branch, Greenbelt, MD 20771 USA.
USA, Res Lab, Adelphi, MD 20783 USA.
Univ Maryland, Dept Elect & Comp Engn, College Pk, MD 20742 USA.
RP Mohammad, SN (reprint author), Howard Univ, Dept Elect Engn, 2300 6th St NW, Washington, DC 20059 USA.
EM snmohammad2002@yahoo.com
NR 38
TC 26
Z9 28
U1 1
U2 17
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0021-8979
J9 J APPL PHYS
JI J. Appl. Phys.
PD SEP 15
PY 2004
VL 96
IS 6
BP 3286
EP 3295
DI 10.1063/1.1769096
PG 10
WC Physics, Applied
SC Physics
GA 851XO
UT WOS:000223720000036
ER
PT J
AU Lerttamrab, M
Chuang, SL
Yang, RQ
Hill, CJ
AF Lerttamrab, M
Chuang, SL
Yang, RQ
Hill, CJ
TI Linewidth enhancement factor of a type-II interband-cascade laser
SO JOURNAL OF APPLIED PHYSICS
LA English
DT Article
ID AMPLIFIED SPONTANEOUS EMISSION; ROOM-TEMPERATURE; MU-M; GAIN;
SPECTROSCOPY
AB Experimental results using the amplified spontaneous emission spectroscopy of a type-II interband-cascade laser are presented. Using the Hakki-Paoli method, the optical gain spectra of the laser are extracted for the wavelength of 3.13 mum at various subthreshold current levels. A group index of around 3.33 is determined from Fabry-Perot modal spacing. The change in refractive index with increased bias current is obtained from the peak wavelength shifts of the Fabry-Perot spectrum. A low value of 0.71 for the linewidth enhancement factor at the lasing wavelength near threshold is found. (C) 2004 American Institute of Physics.
C1 Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Lerttamrab, M (reprint author), Univ Illinois, Dept Elect & Comp Engn, 1406 W Green St, Urbana, IL 61801 USA.
NR 17
TC 2
Z9 2
U1 0
U2 3
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0021-8979
J9 J APPL PHYS
JI J. Appl. Phys.
PD SEP 15
PY 2004
VL 96
IS 6
BP 3568
EP 3570
DI 10.1063/1.1782269
PG 3
WC Physics, Applied
SC Physics
GA 851XO
UT WOS:000223720000089
ER
PT J
AU Skoug, RM
Gosling, JT
Steinberg, JT
McComas, DJ
Smith, CW
Ness, NF
Hu, Q
Burlaga, LF
AF Skoug, RM
Gosling, JT
Steinberg, JT
McComas, DJ
Smith, CW
Ness, NF
Hu, Q
Burlaga, LF
TI Extremely high speed solar wind: 29-30 October 2003
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
DE high-speed solar wind; extreme solar wind; coronal mass ejections;
interplanetary shocks; solar wind plasma; interplanetary magnetic field
ID ADVANCED COMPOSITION EXPLORER; CORONAL MASS EJECTION; ALPHA MONITOR
SWEPAM; PROTON; ELECTRON; ORBIT
AB [1] On 29 - 30 October 2003 the Solar Wind Electron Proton Alpha Monitor (SWEPAM) instrument on the Advanced Composition Explorer ( ACE) spacecraft measured solar wind speeds in excess of 1850 km/s, some of the highest speeds ever directly measured in the solar wind. These speeds were observed following two large coronal mass ejection (CME) driven shocks. Surprisingly, despite the unusually high speeds, many of the other solar wind parameters were not particularly unusual in comparison with other large transient events. The magnetic field reached - 68 nT, a large but not unprecedented value. The proton temperatures were significantly higher than typical for a CME in the solar wind at 1 AU (> 10(7) K), but the proton densities were moderate, leading to low to moderate proton beta. The solar wind dynamic pressure was not unusual for large events but, when coupled with the large negative B-z, was sufficient to cause intense geomagnetic disturbances.
C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA.
SW Res Inst, Instrumentat & Space Res Div, San Antonio, TX 78238 USA.
Univ New Hampshire, Inst Earth Oceans & Space, Durham, NH 03824 USA.
Univ Delaware, Bartol Res Inst, Newark, DE 19711 USA.
Univ Calif Riverside, Inst Geophys & Planetary Phys, Riverside, CA 92521 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Skoug, RM (reprint author), Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA.
EM rskoug@lanl.gov
NR 20
TC 152
Z9 154
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD SEP 15
PY 2004
VL 109
IS A9
AR A09102
DI 10.1029/2004JA010494
PG 9
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857NT
UT WOS:000224125100005
ER
PT J
AU Videen, G
Yatskiv, YS
Mishchenko, MI
AF Videen, G
Yatskiv, YS
Mishchenko, MI
TI Photopolarimetry in remote sensing - Preface
SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
LA English
DT Editorial Material
C1 USA, Res Lab, Adelphi, MD 20783 USA.
Natl Acad Sci Ukraine, Main Astron Observ, Kiev, Ukraine.
NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
RP Videen, G (reprint author), USA, Res Lab, Adelphi, MD 20783 USA.
EM gvideen@art.army.mil
RI Mishchenko, Michael/D-4426-2012
NR 2
TC 3
Z9 3
U1 0
U2 2
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0022-4073
J9 J QUANT SPECTROSC RA
JI J. Quant. Spectrosc. Radiat. Transf.
PD SEP 15
PY 2004
VL 88
IS 1-3
BP 1
EP 2
DI 10.1016/j.jqsrt.2004.05.001
PG 2
WC Optics; Spectroscopy
SC Optics; Spectroscopy
GA 847SQ
UT WOS:000223415600001
ER
PT J
AU Dlugach, JA
Mishchenko, MI
AF Dlugach, JA
Mishchenko, MI
TI The effect of particle shape on microphysical properties of Jovian
aerosols retrieved from ground-based spectropolarimetric observations
SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
LA English
DT Article; Proceedings Paper
CT Conference of the NATO-Advanced-Study-Institute on Photopolarimetry in
Remote Sensing
CY SEP 20-OCT 03, 2003
CL Yalta, UKRAINE
SP NATO, Adv Study Inst
DE photopolarimetric measurements; atmospheric aerosols; particle shape;
refractive index; remote sensing; atmosphere of Jupiter
ID LIGHT-SCATTERING; WAVELENGTH DEPENDENCE; TROPOSPHERIC AEROSOLS;
OPTICAL-PROPERTIES; POLARIZATION; JUPITER; VENUS; ATMOSPHERE
AB In this paper we study potential errors in the retrieved values of the cloud particle refractive index and size that may result from the neglect of nonsphericity in analyses of ground-based spectropolarimetric observations of Jupiter. Using T-matrix and vector radiative-transfer codes, we have carried out numerous computations in the spectral range from 0.423 to 0.798 mum for a plane-parallel model atmosphere comprising polydisperse ensembles of randomly oriented oblate and prolate spheroids with sizes comparable to the wavelength. The particle models were specified by a gamma size distribution with varying values of the effective radius and effective variance and by a varying refractive index. Two models of the Jovian atmosphere were considered: (i) a homogeneous semi-infinite layer composed of gas and cloud particles; and (ii) a two-layered medium with a layer of pure gas on top of a semi-infinite homogeneous layer composed of gas and cloud particles. Good agreement between ground-based observational data of the brightness and the degree of linear polarization for the center of the Jovian disk and model computations was found for the following combinations of the real part of the refractive index m(R), the effective radius r(eff), and the effective variance v(eff): m(R) = 1.45, r(eff) = 0.35 mum, v(eff) = 0.40 for oblate spheroids with an axial ratio of a/b = 1.3; m(R) = 1.50, r(eff) = 0.35 mum, v(eff) = 0.30 for prolate spheroids with a/b = 1/1.3; m(R) = 1.52, r(eff) = 0.40 mum, v(eff) = 0.35 for oblate spheroids with a/b = 1.5, and m(R) = 1.54, r(eff) = 0.90 mum, v(eff) = 0.30 for prolate spheroids with a/b = 1/1.5. These values (especially the real part of the refractive index) differ quite significantly from those retrieved previously for the model of spherical cloud particles and emphasize nonuniqueness of remote-sensing retrievals based on the ground-based data alone. Published by Elsevier Ltd.
C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
Natl Acad Sci Ukraine, Main Astron Observ, UA-03680 Kiev, Ukraine.
RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA.
EM mniishchenko@giss.nasa.gov
RI Mishchenko, Michael/D-4426-2012
NR 26
TC 3
Z9 3
U1 0
U2 1
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0022-4073
J9 J QUANT SPECTROSC RA
JI J. Quant. Spectrosc. Radiat. Transf.
PD SEP 15
PY 2004
VL 88
IS 1-3
BP 37
EP 46
DI 10.1016/j.jqsrt.2004.03.023
PG 10
WC Optics; Spectroscopy
SC Optics; Spectroscopy
GA 847SQ
UT WOS:000223415600006
ER
PT J
AU Geogdzhayev, IV
Mishchenko, MI
Liu, L
Remer, L
AF Geogdzhayev, IV
Mishchenko, MI
Liu, L
Remer, L
TI Global two-channel AVHRR aerosol climatology: effects of stratospheric
aerosols and preliminary comparisons with MODIS and MISR retrievals
SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
LA English
DT Article; Proceedings Paper
CT Conference of the NATO-Advanced-Study-Institute on Photopolarimetry in
Remote Sensing
CY SEP 20-OCT 04, 2003
CL Yalta, UKRAINE
SP NATO, Adv Study Inst
DE atmospheric aerosols; optical thickness; remote sensing
ID OPTICAL DEPTH; OCEAN; RADIANCES; SENSITIVITY; ALGORITHM; CHANNELS; MODEL
AB We present an update on the status of the global climatology of the aerosol column optical thickness and Angstrom exponent derived from channel-1 and -2 radiances of the Advanced Very High Resolution Radiometer (AVHRR) in the framework of the Global Aerosol Climatology Project (GACP). The latest version of the climatology covers the period from July 1983 to September 2001 and is based on an adjusted value of the diffuse component of the ocean reflectance as derived from extensive comparisons with ship sun-photometer data. We use the updated GACP climatology and Stratospheric Aerosol and Gas Experiment (SAGE) data to analyze how stratospheric aerosols from major volcanic eruptions can affect the GACP aerosol product. One possible retrieval strategy based on the AVHRR channel-1 and -2 data alone is to infer both the stratospheric and the tropospheric aerosol optical thickness while assuming fixed microphysical models for both aerosol components. The second approach is to use the SAGE stratospheric aerosol data in order to constrain the AVHRR retrieval algorithm. We demonstrate that the second approach yields a consistent long-term record of the tropospheric aerosol optical thickness and Angstrom exponent. Preliminary comparisons of the GACP aerosol product with MODerate resolution Imaging Spectrometer (MODIS) and Multiangle Imaging Spectro-Radiometer aerosol retrievals show reasonable agreement, the GACP C Global monthly optical thickness being lower than the MODIS one by approximately 0.03. Larger differences are observed on a regional scale. Comparisons of the GACP and MODIS Angstrom exponent records are less conclusive and require further analysis. Published by Elsevier Ltd.
C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA.
Columbia Univ, Dept Earth & Environm Sci, New York, NY 10025 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA.
EM crmim@giss.nasa.gov
RI Mishchenko, Michael/D-4426-2012
NR 21
TC 23
Z9 23
U1 0
U2 5
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0022-4073
EI 1879-1352
J9 J QUANT SPECTROSC RA
JI J. Quant. Spectrosc. Radiat. Transf.
PD SEP 15
PY 2004
VL 88
IS 1-3
BP 47
EP 59
DI 10.1016/j.jqsrt.2004.03.024
PG 13
WC Optics; Spectroscopy
SC Optics; Spectroscopy
GA 847SQ
UT WOS:000223415600007
ER
PT J
AU Liu, L
Mishchenko, MI
Geogdzhayev, I
Smirnov, A
Sakerin, SM
Kabanov, DM
Ershov, OA
AF Liu, L
Mishchenko, MI
Geogdzhayev, I
Smirnov, A
Sakerin, SM
Kabanov, DM
Ershov, OA
TI Global validation of two-channel AVHRR aerosol optical thickness
retrievals over the oceans
SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
LA English
DT Article; Proceedings Paper
CT Conference of the NATO-Advanced-Study-Institute on Photopolarimetry in
Remote Sensing
CY SEP 20-OCT 04, 2003
CL Yalta, UKRAINE
SP NATO, Adv Study Inst
DE atmospheric aerosols; optical thickness; remote sensing
ID NORTH-ATLANTIC; ATMOSPHERIC AEROSOL; SATELLITE; DEPTH; SUN; DUST; SEA;
CLIMATOLOGY; VARIABILITY; SENSITIVITY
AB The paper presents validation results for the aerosol optical thickness derived by applying a two-channel retrieval algorithm to Advanced Very High Resolution Radiometer (AVHRR) radiance data. The satellite retrievals are compared with ship-borne sun-photometer results. The comparison of spatial and temporal statistics of the AVHRR results and the ship measurements shows a strong correlation. The satellite retrieval results obtained with the original algorithm for a wavelength of 0.55 mum are systematically higher than the sun-photometer measurements in the cases of low aerosol loads. The ensemble averaged satellite-retrieved optical thickness overestimates the ensemble averaged sun-photometer data by about 11% with a random error of about 0.04. Increasing the diffuse component of the ocean surface reflectance from 0.002 to 0.004 in the AVHRR algorithm produces a better match, with the ensemble-averaged AVHRR-retrieved optical thickness differing by only about 3.6% from the sun-photometer truth and having a small offset of 0.03. Published by Elsevier Ltd.
C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
Columbia Univ, Dept Earth & Environm Sci, New York, NY 10025 USA.
Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Inst Atmospher Opt, Tomsk 634055, Russia.
Univ Texas, Austin, TX 78712 USA.
RP NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA.
EM crmim@giss.nasa.gov
RI Smirnov, Alexander/C-2121-2009; Mishchenko, Michael/D-4426-2012
OI Smirnov, Alexander/0000-0002-8208-1304;
NR 49
TC 20
Z9 21
U1 0
U2 5
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0022-4073
EI 1879-1352
J9 J QUANT SPECTROSC RA
JI J. Quant. Spectrosc. Radiat. Transf.
PD SEP 15
PY 2004
VL 88
IS 1-3
BP 97
EP 109
DI 10.1016/j.jqsrt.2004.03.031
PG 13
WC Optics; Spectroscopy
SC Optics; Spectroscopy
GA 847SQ
UT WOS:000223415600012
ER
PT J
AU Mishchenko, MI
Liu, L
Travis, LD
Lacis, AA
AF Mishchenko, MI
Liu, L
Travis, LD
Lacis, AA
TI Scattering and radiative properties of semi-external versus external
mixtures of different aerosol types
SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
LA English
DT Article; Proceedings Paper
CT Conference of the NATO-Advanced-Study-Institute on Photopolarimetry in
Remote Sensing
CY SEP 20-OCT 03, 2003
CL Yalta, UKRAINE
SP NATO, Adv Study Inst
DE aerosols; scattering; optical cross sections; single-scattering albedo;
asymmetry parameter; scattering matrix; remote sensing; atmospheric
radiation
ID LIGHT-SCATTERING; CROSS-SECTIONS; BLACK CARBON; PARTICLES; BISPHERES;
SPHERES
AB The superposition T-matrix method is used to compute the scattering of unpolarized light by semi-external aerosol mixtures in the form of polydisperse, randomly oriented two-particle clusters with touching components. The results are compared with those for composition-equivalent external aerosol mixtures, in which the components are widely separated and scatter light in isolation from each other. It is concluded that aggregation is likely to have a relatively weak effect on scattering and radiative properties of two-component tropospheric aerosols and can be replaced by the much simpler external-mixture model in remote sensing studies and atmospheric radiation balance computations. Published by Elsevier Ltd.
C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
Columbia Univ, Dept Earth & Environm Sci, New York, NY 10025 USA.
RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA.
EM crmim@giss.nasa.gov
RI Lacis, Andrew/D-4658-2012; Mishchenko, Michael/D-4426-2012
NR 15
TC 37
Z9 38
U1 1
U2 4
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0022-4073
J9 J QUANT SPECTROSC RA
JI J. Quant. Spectrosc. Radiat. Transf.
PD SEP 15
PY 2004
VL 88
IS 1-3
BP 139
EP 147
DI 10.1016/j.jqsrt.2003.12.032
PG 9
WC Optics; Spectroscopy
SC Optics; Spectroscopy
GA 847SQ
UT WOS:000223415600015
ER
PT J
AU Mishchenko, MI
Cairns, B
Hansen, JE
Travis, LD
Burg, R
Kaufman, YJ
Martins, JV
Shettle, EP
AF Mishchenko, MI
Cairns, B
Hansen, JE
Travis, LD
Burg, R
Kaufman, YJ
Martins, JV
Shettle, EP
TI Monitoring of aerosol forcing of climate from space: analysis of
measurement requirements
SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
LA English
DT Article; Proceedings Paper
CT Conference of the NATO-Advanced-Study-Institute on Photopolarimetry in
Remote Sensing
CY SEP 20-OCT 03, 2003
CL Yalta, UKRAINE
SP NATO, Adv Study Inst
DE aerosols; climate forcings; long-term monitoring; remote sensing;
polarimetry
ID CLOSURE EXPERIMENT; OPTICAL-PROPERTIES; OCEAN; RETRIEVALS; SATELLITE;
SENSITIVITY; MULTIANGLE; CLOUDS; ACE-2; INSTRUMENT
AB We discuss the rationale for long-term monitoring of the global distribution of natural and anthropogenic aerosols (black carbon, sulfates, mineral aerosols, etc.) and clouds with specificity, accuracy, and coverage sufficient for a reliable quantification of the direct and indirect aerosol effects on climate, the anthropogenic component of these effects, and the long-term change of these effects caused by natural and anthropogenic factors. This discussion is followed by the formulation of specific scientific objectives of the Aerosol Polarimetry Sensor component of the National Aeronautics and Space Administration's Glory Project established within the framework of the US Climate Change Research Initiative. Published by Elsevier Ltd.
C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA.
RP Mishchenko, MI (reprint author), NASA, Goddard Inst Space Studies, 2800 Broadway, New York, NY 10025 USA.
EM crmim@giss.nasa.gov
RI Mishchenko, Michael/D-4426-2012;
OI Cairns, Brian/0000-0002-1980-1022
NR 50
TC 112
Z9 116
U1 5
U2 16
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0022-4073
J9 J QUANT SPECTROSC RA
JI J. Quant. Spectrosc. Radiat. Transf.
PD SEP 15
PY 2004
VL 88
IS 1-3
BP 149
EP 161
DI 10.1016/j.jqsrt.2004.03.030
PG 13
WC Optics; Spectroscopy
SC Optics; Spectroscopy
GA 847SQ
UT WOS:000223415600016
ER
PT J
AU Mishchenko, MI
Videen, G
Babenko, VA
Khlebtsov, NG
Wriedt, T
AF Mishchenko, MI
Videen, G
Babenko, VA
Khlebtsov, NG
Wriedt, T
TI T-matrix theory of electromagnetic scattering by particles and its
applications: a comprehensive reference database
SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
LA English
DT Article; Proceedings Paper
CT Conference of the NATO-Advanced-Study-Institute on Photopolarimetry in
Remote Sensing
CY SEP 20-OCT 04, 2003
CL Yalta, UKRAINE
SP NATO, Adv Study Inst
DE electromagnetic scattering; T-matrix method
ID EXTENDED-BOUNDARY-CONDITION; NULL-FIELD METHOD; MORPHOLOGY-DEPENDENT
RESONANCES; POLAR STRATOSPHERIC CLOUDS; MONTE-CARLO SIMULATIONS;
DISCRETE RANDOM-MEDIA; PLANE-WAVE SCATTERING; ABSORPTION CROSS-SECTIONS;
PROLATE SPHEROIDAL MODELS; AXIALLY-SYMMETRICAL PARTICLES
AB The T-matrix method is one of the most powerful and widely used theoretical techniques for the computation of electromagnetic scattering by single and composite particles, discrete random media, and particles in the vicinity of an interface separating two half-spaces with different refractive indices. This paper presents a comprehensive database of T-matrix publications since the inception of the technique in 1965 through early 2004.
C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
USA, Res Lab, AMSRL IS EE, Adelphi, MD 20783 USA.
Natl Acad Sci Belarus, BI Stepanov Phys Inst, Minsk 220072, Byelarus.
Russian Acad Sci, Inst Biochem & Physiol Plants & Microorganisms, Saratov 410015, Russia.
Inst Werkstofftech, D-28359 Bremen, Germany.
RP NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA.
EM crmim@giss.nasa.gov
RI Mishchenko, Michael/D-4426-2012; Khlebtsov, Nikolai/D-6199-2017; Pylaev,
Timofey/A-8401-2016;
OI Pylaev, Timofey/0000-0002-2701-3333; Khlebtsov,
Nikolai/0000-0002-2055-7784
NR 731
TC 121
Z9 124
U1 3
U2 30
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0022-4073
EI 1879-1352
J9 J QUANT SPECTROSC RA
JI J. Quant. Spectrosc. Radiat. Transf.
PD SEP 15
PY 2004
VL 88
IS 1-3
BP 357
EP 406
DI 10.1016/j.jqsrt.2004.05.002
PG 50
WC Optics; Spectroscopy
SC Optics; Spectroscopy
GA 847SQ
UT WOS:000223415600032
ER
PT J
AU Raj, SV
AF Raj, SV
TI Tensile creep fracture of polycrystalline near-stoichiometric NiAl
SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES
MICROSTRUCTURE AND PROCESSING
LA English
DT Article
DE creep fracture; NiAl; rupture life; cleavage; voids; fracture mechanism
map
ID PLASTIC-FLOW PROPERTIES; MECHANISM MAPS; GRAIN-SIZE; TEMPERATURE;
DIFFUSION; STRESS; METALS; ALLOYS; VOIDS; FCC
AB Tensile creep fracture behavior of polycrystalline near-stoichiometric NiAl was studied between 700 and 1200 K under initial applied stresses varying between 10 and 200 MPa. The stress exponent for fracture varied between 5.0 and 10.7 while the activation energy for fracture was 250 +/- 22 kJ mol(-1). The fracture life was inversely proportional to the secondary creep rate in accordance with the Monkman-Grant relation although there was extensive scatter in the data. This observation suggests that the fracture life for near-stoichiometric NiAl was influenced by creep under these stress and temperature conditions. Several different fracture morphologies were observed. Transgranular ductile cleavage fracture occurs at 700 K and at the higher stresses at 800 K. The fracture mode transitions to transgranular creep fracture at 900 and 1000 K and at lower stresses at 800 K, while plastic rupture and grain boundary cavitation occur at 1100 and 1200 K. An experimental fracture mechanism map is constructed for near-stoichiometric NiAl. (C) 2004 Elsevier B.V. All rights reserved.
C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Raj, SV (reprint author), NASA, Glenn Res Ctr, MS 106-5,21000 Brookpk Rd, Cleveland, OH 44135 USA.
EM sai.v.raj@nasa.gov
NR 36
TC 2
Z9 2
U1 0
U2 1
PU ELSEVIER SCIENCE SA
PI LAUSANNE
PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND
SN 0921-5093
J9 MAT SCI ENG A-STRUCT
JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process.
PD SEP 15
PY 2004
VL 381
IS 1-2
BP 154
EP 164
DI 10.1016/j.msea.2004.04.003
PG 11
WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary;
Metallurgy & Metallurgical Engineering
SC Science & Technology - Other Topics; Materials Science; Metallurgy &
Metallurgical Engineering
GA 852ER
UT WOS:000223738500020
ER
PT J
AU Bertone, G
Nezri, E
Orloff, J
Silk, J
AF Bertone, G
Nezri, E
Orloff, J
Silk, J
TI Neutrinos from dark matter annihilations at the galactic center
SO PHYSICAL REVIEW D
LA English
DT Article
ID MILKY-WAY; NEUTRALINO ANNIHILATION; E(+)E(-) COLLISIONS; GAMMA-RAYS;
RADIATION; GALAXIES; PHOTINO; SEARCH; HALOS; PROBE
AB We discuss the prospects for detection of high energy neutrinos from dark matter (DM) annihilation at the galactic center (GC). Despite the large uncertainties associated with our poor knowledge of the distribution of dark matter in the innermost regions of the Galaxy, we determine an upper limit on the neutrino flux by requiring that the associated gamma-ray emission does not exceed the observed flux. We conclude that a neutrino flux from the GC will not be observable by Antares if dark matter is made of neutralinos with mass smaller than 650 GeV, while for heavier neutralinos, corresponding to models that will soon be probed by HESS (high energy stereoscopic system), the upper limit on the neutrino flux is barely above the Antares sensitivity. The detection of a larger flux would either require an alternative explanation, in terms of astrophysical processes, or the adoption of other dark matter candidates, disfavouring the case for neutralinos.
C1 NASA, Fermilab Theoret Astrophys Grp, Batavia, IL 60510 USA.
Univ Paris 11, Lab Phys Theor Hautes Energies, F-91405 Orsay, France.
Univ Clermont Ferrand, Phys Corpusculaire Lab, F-63177 Clermont Ferrand, France.
RP Bertone, G (reprint author), NASA, Fermilab Theoret Astrophys Grp, Batavia, IL 60510 USA.
RI Orloff, Jean/A-8543-2008;
OI Orloff, Jean/0000-0002-8482-0748; silk, joe/0000-0002-1566-8148
NR 58
TC 27
Z9 27
U1 0
U2 0
PU AMERICAN PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 0556-2821
J9 PHYS REV D
JI Phys. Rev. D
PD SEP 15
PY 2004
VL 70
IS 6
AR 063503
DI 10.1103/PhysRevD.70.063503
PG 8
WC Astronomy & Astrophysics; Physics, Particles & Fields
SC Astronomy & Astrophysics; Physics
GA 862AS
UT WOS:000224462000015
ER
PT J
AU Tinto, M
Larson, SL
AF Tinto, M
Larson, SL
TI LISA time-delay interferometry zero-signal solution: Geometrical
properties
SO PHYSICAL REVIEW D
LA English
DT Article
AB Time-delay interferometry (TDI) is the data processing technique needed for generating interferometric combinations of data measured by the multiple Doppler readouts available onboard the three Laser Interferometer Space Antenna (LISA) spacecraft. Within the space of all possible interferometric combinations TDI can generate, we have derived a specific combination that has zero response to the gravitational wave signal, and called it the zero-signal solution (ZSS). This is a two-parameter family of linear combinations of the generators of the TDI space, and its response to a gravitational wave becomes null when these two parameters coincide with the values of the angles of the source location in the sky. Remarkably, the ZSS does not rely on any assumptions about the gravitational waveform, and in fact it works for waveforms of any kind. Our approach is analogous to the data analysis method introduced by Gursel and Tinto in the context of networks of Earth-based, wideband, interferometric gravitational wave detectors observing in coincidence a gravitational wave burst. The ZSS should be regarded as an application of the Gursel and Tinto method to the LISA data.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA.
RP Tinto, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Massimo.Tinto@jpl.nasa.gov; shane@srl.caltech.edu
RI Larson, Shane/E-8576-2010
NR 19
TC 8
Z9 8
U1 0
U2 0
PU AMERICAN PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 0556-2821
J9 PHYS REV D
JI Phys. Rev. D
PD SEP 15
PY 2004
VL 70
IS 6
AR 062002
DI 10.1103/PhysRevD.70.062002
PG 13
WC Astronomy & Astrophysics; Physics, Particles & Fields
SC Astronomy & Astrophysics; Physics
GA 862AS
UT WOS:000224462000007
ER
PT J
AU Ajtic, JV
Connor, BJ
Lawrence, BN
Bodeker, GE
Hoppel, KW
Rosenfield, JE
Heuff, DN
AF Ajtic, JV
Connor, BJ
Lawrence, BN
Bodeker, GE
Hoppel, KW
Rosenfield, JE
Heuff, DN
TI Dilution of the Antarctic ozone hole into southern midlatitudes,
1998-2000
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
ID STRATOSPHERIC POLAR VORTEX; CHEMICAL-TRANSPORT MODEL; POAM-III
OBSERVATIONS; NEW-ZEALAND; GLOBAL IMPACT; 3-DIMENSIONAL TRANSPORT;
MIXING PROPERTIES; AIR; DEPLETION; TROPOSPHERE
AB [1] The reduction in southern midlatitude ozone is quantified by evaluating the trajectories of ozone-depleted air masses, assuming that photochemical recovery of ozone in advected air parcels can be ignored. This procedure is carried out for the 3 months from 15 October to 15 January for each of the years 1998, 1999, and 2000. Two distinct source regions, the vortex core and the vortex edge, are considered, and for each day, diabatic reverse domain filling calculations are performed for an ensemble of parcels between 30 degreesS and 60 degreesS and 400 - 700 K in altitude. In 1998, 1999, and 2000 the mean calculated ozone reduction is 16, 18, and 19 DU, respectively. Air parcels from the vortex edge region are significant contributors to the reduction, especially during spring. Results for four longitudinal and three latitudinal midlatitude subregions are also presented. A comparison with the Total Ozone Mapping Spectrometer measurements of total column ozone shows that without the dilution, ozone over Southern Hemisphere midlatitudes would be 5 - 6% higher during spring and summer. This result is probably an overestimate due to the neglect of photochemical recovery.
C1 Natl Inst Water & Atmospher Res Lauder, Omakau 9182, Central Otago, New Zealand.
Univ Canterbury, Dept Phys & Astron, Christchurch 8020, New Zealand.
Rutherford Appleton Lab, British Atmospher Data Ctr, Didcot OX11 0QX, Oxon, England.
USN, Res Lab, Remote Sensing Phys Branch, Washington, DC 20375 USA.
NASA, Goddard Space Flight Ctr, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA.
RP Natl Inst Water & Atmospher Res Lauder, Privat Bag 50061, Omakau 9182, Central Otago, New Zealand.
EM j.ajtic@niwa.co.nz; b.connor_@niwa.co.nz; b.n.lawrence@rl.ac.uk;
g.bodeker@niwa.cri.nz; karl.hoppel@nrl.navy.mil;
rose@euterpe.gsfc.nasa.gov; d.heuff@canterbury.ac.nz
OI Lawrence, Bryan/0000-0001-9262-7860
NR 51
TC 14
Z9 14
U1 0
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 14
PY 2004
VL 109
IS D17
AR D17107
DI 10.1029/2003JD004500
PG 9
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 857NE
UT WOS:000224123300004
ER
PT J
AU Refaat, TF
Abedin, MN
Bhagwat, V
Bhat, IB
Dutta, PS
Singh, UN
AF Refaat, TF
Abedin, MN
Bhagwat, V
Bhat, IB
Dutta, PS
Singh, UN
TI InGaSb photodetectors using an InGaSb substrate for 2 mu m applications
SO APPLIED PHYSICS LETTERS
LA English
DT Article
ID GROWTH; GASB; GAAS
AB Detectors operating at 2 mum are important for several applications including optical communication and atmospheric remote sensing. In this letter, fabrication of 2 mum photodetectors using an InGaSb substrate is reported. The ternary substrates were grown using vertical Bridgmann technique and Zn diffusion was used to fabricate p-n junction diodes and photodiodes. Dark current measurement reveals that the breakdown voltage is in the 0.75 to 1 V range. Spectral response measurements indicated a 2 mum responsivity of 0.56 A/W corresponding to 35% quantum efficiency. Photodiode performance was compared to similar devices fabricated on binary substrates. (C) 2004 American Institute of Physics.
C1 NASA, Langley Res Ctr, Sci & Technol Corp, Hampton, VA 23681 USA.
NASA, Langley Res Ctr, Laser & Electroopt Branch, Hampton, VA 23681 USA.
Rensselaer Polytech Inst, Dept Elect Comp & Syst Engn, Troy, NY 12180 USA.
RP Refaat, TF (reprint author), NASA, Langley Res Ctr, Sci & Technol Corp, MS 468,Bldg 1202,Room 243, Hampton, VA 23681 USA.
EM fn.t.f.refaat@larc.nasa.gov
NR 9
TC 15
Z9 15
U1 2
U2 4
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0003-6951
J9 APPL PHYS LETT
JI Appl. Phys. Lett.
PD SEP 13
PY 2004
VL 85
IS 11
BP 1874
EP 1876
DI 10.1063/1.1787893
PG 3
WC Physics, Applied
SC Physics
GA 854SJ
UT WOS:000223923300002
ER
PT J
AU Chaban, GM
AF Chaban, GM
TI On the stability of HKrOH: a theoretical study
SO CHEMICAL PHYSICS LETTERS
LA English
DT Article
ID CHEMICALLY BOUND HELIUM; DECOMPOSITION PATHWAYS; METASTABLE COMPOUND;
PREDICTION; CONFIGURATION; LIFETIME; HYDROGEN; SYSTEMS; ARGON; HARF
AB To provide further insight into the issue of stability of HKrOH, reaction paths for decomposition processes HKrOH --> Kr + H(2)O and HKrOH --> H + Kr + OH are studied using ab initio electronic structure methods. The results show that HKrOH molecule is energetically unstable with respect to the Kr + H(2)O and H + Kr + OH dissociation products. However, it is separated by a significant energy barrier from Kr + H(2)O (similar to35 kcal/mol) and by a much lower barrier from H + Kr + OH (similar to3 kcal/mol). Thus, theoretical studies show that HKrOH is kinetically stable with respect to the HKrOH --> Kr + H(2)O channel of decomposition, but its stability with respect to H + Kr + OH is marginal. The low barrier for the HKrOH --> H + Kr + OH process (which leads to a high probability of HKrOH dissociation to H + Kr + OH) and the relatively high barrier (similar to25 kcal/mol) for the reverse reaction (H + Kr + OH --> HKrOH) seem to be responsible for the fact that HKrOH (unlike HKrF) has not been observed experimentally. Published by Elsevier B.V.
C1 NASA, Ames Res Ctr, INA, Moffett Field, CA 94035 USA.
RP Chaban, GM (reprint author), NASA, Ames Res Ctr, INA, Mail Stop T27B-1, Moffett Field, CA 94035 USA.
EM chaban@nas.nasa.gov
NR 21
TC 15
Z9 15
U1 0
U2 4
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0009-2614
J9 CHEM PHYS LETT
JI Chem. Phys. Lett.
PD SEP 11
PY 2004
VL 395
IS 4-6
BP 182
EP 185
DI 10.1016/j.cplett.2004.07.059
PG 4
WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical
SC Chemistry; Physics
GA 852PX
UT WOS:000223770000002
ER
PT J
AU Haddad, ZS
Meagher, JP
Adler, RF
Smith, EA
Im, E
Durden, SL
AF Haddad, ZS
Meagher, JP
Adler, RF
Smith, EA
Im, E
Durden, SL
TI Global variability of precipitation according to the Tropical Rainfall
Measuring Mission
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE rainfall
ID SOUTHERN OSCILLATION; SATELLITE; PATTERNS; INDEXES
AB Numerous studies have documented the effect of El Nino-Southern Oscillation (ENSO) on rainfall in many regions of the globe. The question of whether ENSO is the single most important factor in interannual rainfall variability has received less attention, mostly because the kind of data that would be required to make such an assessment were simply not available. Until 1979 the evidence linking El Nino with changes in rainfall around the world came from rain gauges measuring precipitation over land masses and a handful of islands. From 1980 until the launch of the Tropical Rainfall Measuring Mission (TRMM) in November 1997 the remote sensing evidence was confined to ocean rainfall because of the very poor sensitivity of the instruments over land. In this paper we summarize the results of a principal component analysis of TRMM's 60-month (January 1998 to December 2002) global land and ocean remote-sensing record of monthly rainfall accumulations. Contrary to the first principal component of the rainfall itself, the first three indices of the anomaly are most sensitive to precipitation over the ocean rather than over the land. With the help of archived surface station data the first TRMM rain anomaly index is extended back several decades. Comparison of the extended index with the Southern Oscillation Index confirms that the first principal component of the rainfall anomaly is strongly correlated with the ENSO indices.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Haddad, ZS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM zsh@titan.jpl.nasa.gov
NR 16
TC 13
Z9 14
U1 2
U2 7
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 11
PY 2004
VL 109
IS D17
AR D17103
DI 10.1029/2004JD004607
PG 7
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 854HF
UT WOS:000223892400002
ER
PT J
AU Baines, D
Oudmaijer, RD
Mora, A
Eiroa, C
Porter, JM
Merin, B
Montesinos, B
de Winter, D
Carneron, A
Davies, JK
Deeg, HJ
Ferlet, R
Grady, CA
Harris, AW
Hoare, MG
Horne, K
Lumsden, SL
Miranda, LF
Penny, A
Quirrenbach, A
AF Baines, D
Oudmaijer, RD
Mora, A
Eiroa, C
Porter, JM
Merin, B
Montesinos, B
de Winter, D
Carneron, A
Davies, JK
Deeg, HJ
Ferlet, R
Grady, CA
Harris, AW
Hoare, MG
Horne, K
Lumsden, SL
Miranda, LF
Penny, A
Quirrenbach, A
TI The pre-main-sequence binary HK Ori: spectro-astrometry and EXPORT data
SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
LA English
DT Article
DE techniques : spectroscopic; binaries : spectroscopic; stars : individual
: HK Ori; stars : pre-main-sequence
ID T-TAURI STARS; HERBIG AE/BE STARS; VEGA-TYPE; EMISSION; ACCRETION;
SEARCH; VARIABILITY; ORIONIS; DUST; AE
AB In this paper we present multi-epoch observations of the pre-main-sequence binary HK Ori. These data have been drawn from the EXPORT data base and are complemented by high-quality spectro-astrometric data of the system. The spectroscopic data appear to be very well represented by a combination of an A dwarf star spectrum superposed on a (sub)giant G-type spectrum. The radial velocity of the system is consistent with previous determinations, and does not reveal binary motion, as expected for a wide binary. The spectral, photometric and polarimetric properties and variability of the system indicate that the active object in the system is a T Tauri star with UX Ori characteristics. The spectro-astrometry of HK Ori is sensitive down to milliarcsecond scales and confirms the speckle interferometric results from Leinert et al. The spectro-astrometry allows the identification, with fair certainty, of the active star within the binary, which we suggest to be a G-type T Tauri star based on its spectral characteristics.
C1 Univ Leeds, Sch Phys & Astron, Leeds LS2 9JT, W Yorkshire, England.
Univ Oxford, Dept Astrophys, UK Gemini Support Grp, Oxford OX1 3RH, England.
Univ Autonoma Madrid, Fac Ciencias, Dept Fis Teor, E-28049 Madrid, Spain.
Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England.
Lab Astrofis Espacial & Fis Fundamental, Madrid 28080, Spain.
CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain.
TNO, TPD Space Instrumentat, NL-2600 AD Delft, Netherlands.
Univ St Andrews, Dept Phys & Astron, St Andrews KY16 9SS, Fife, Scotland.
Royal Observ, Astron Technol Ctr, Edinburgh EH9 3HJ, Midlothian, Scotland.
Inst Astrofis Canarias, Tenerife 38200, Spain.
CNRS, Inst Astrophys Paris, F-75014 Paris, France.
NASA, Goddard Space Flight Ctr, NOAO, STIS, Greenbelt, MD 20771 USA.
DLR, Dept Planetary Explorat, D-12489 Berlin, Germany.
Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England.
Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands.
RP Baines, D (reprint author), Univ Leeds, Sch Phys & Astron, Leeds LS2 9JT, W Yorkshire, England.
EM roud@ast.leeds.ac.uk
RI Montesinos, Benjamin/C-3493-2017;
OI Montesinos, Benjamin/0000-0002-7982-2095; Cameron,
Andrew/0000-0002-8863-7828; Merin, Bruno/0000-0002-8555-3012
NR 32
TC 15
Z9 15
U1 0
U2 2
PU BLACKWELL PUBLISHING LTD
PI OXFORD
PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND
SN 0035-8711
J9 MON NOT R ASTRON SOC
JI Mon. Not. Roy. Astron. Soc.
PD SEP 11
PY 2004
VL 353
IS 2
BP 697
EP 704
DI 10.1111/j.1365-2966.2004.08104.x
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 856OI
UT WOS:000224054100030
ER
PT J
AU Koch, GJ
Barnes, BW
Petros, M
Beyon, JY
Amzajerdian, F
Yu, JR
Davis, RE
Ismail, S
Vay, S
Kavaya, MJ
Singh, UN
AF Koch, GJ
Barnes, BW
Petros, M
Beyon, JY
Amzajerdian, F
Yu, JR
Davis, RE
Ismail, S
Vay, S
Kavaya, MJ
Singh, UN
TI Coherent differential absorption lidar measurements of CO2
SO APPLIED OPTICS
LA English
DT Article
ID ATMOSPHERIC CO2; AIRBORNE OBSERVATIONS; CARBON-DIOXIDE; WATER-VAPOR; YLF
LASER
AB A differential absorption lidar has been built to measure CO2 concentration in the atmosphere. The transmitter is a pulsed single-frequency Ho:Tm:YLF laser at a 2.05-mum wavelength. A coherent heterodyne receiver was used to achieve sensitive detection, with the additional capability for wind profiling by a Doppler technique. Signal processing includes an algorithm for power measurement of a heterodyne signal. Results show a precision of the CO2 concentration measurement of 1%-2% 1sigma standard deviation over column lengths ranging from 1.2 to 2.8 km by an average of 1000 pulse pairs. A preliminary assessment of instrument sensitivity was made with an 8-h-long measurement set, along with correlative measurements with an in situ sensor, to determine that a CO2 trend could be detected. (C) 2004 Optical Society of America.
C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA.
Sci & Technol Corp, Hampton, VA 23666 USA.
Calif State Univ Los Angeles, Dept Elect & Comp Engn, Los Angeles, CA 90032 USA.
RP Koch, GJ (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA.
EM g.j.koch@larc.nasa.gov
NR 28
TC 117
Z9 124
U1 6
U2 27
PU OPTICAL SOC AMER
PI WASHINGTON
PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA
SN 1559-128X
EI 2155-3165
J9 APPL OPTICS
JI Appl. Optics
PD SEP 10
PY 2004
VL 43
IS 26
BP 5092
EP 5099
DI 10.1364/AO.43.005092
PG 8
WC Optics
SC Optics
GA 853DH
UT WOS:000223806100014
PM 15468711
ER
PT J
AU Eriksen, HK
Banday, AJ
Gorski, KM
Lilje, PB
AF Eriksen, HK
Banday, AJ
Gorski, KM
Lilje, PB
TI On foreground removal from the Wilkinson Microwave Anisotropy Probe data
by an internal linear combination method: Limitations and implications
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE cosmic microwave background; cosmology : observations; methods :
numerical
ID BACKGROUND-RADIATION; WMAP OBSERVATIONS; NON-GAUSSIANITY; MAPS; EMISSION
AB We study the Internal Linear Combination (ILC) method presented by the Wilkinson Microwave Anisotropy Probe (WMAP) science team, with the goal of determining whether it may be used for cosmological purposes, as a template-free alternative to existing foreground-correction methods. We conclude that the method does have the potential to do just that, but great care must be taken both in implementation and in a detailed understanding of limitations caused by residual foregrounds, which can still affect cosmological results. As a first step we demonstrate how to compute the ILC weights both accurately and efficiently by means of Lagrange multipliers, and we apply this method to the observed data to produce a new version of the ILC map. This map has 12% lower variance than the ILC map of the WMAP team, primarily because of less noise. Next we describe how to generate Monte Carlo simulations of the ILC map and find that these agree well with the observed map on angular scales up to lapproximate to200, using a conservative sky cut. Finally we make two comments to the ongoing debates concerning the large-scale properties of the WMAP data. First, we note that the Galactic southeastern quadrant is associated with notably different ILC weights than the other three quadrants, possibly indicating a foreground-related anisotropy. Second, we study the properties of the quadrupole and octopole (amplitude, alignment, and planarity) and reproduce the previously reported results that the quadrupole and octopole are strongly aligned and that the octopole is moderately planar. Even more interestingly, we find that the l=5 mode is spherically symmetric at about 3 sigma, and that the l=6 mode is planar at the 2 sigma level. However, we also assess the impact of residual foregrounds on these statistics, and find that the ILC map is not clean enough to allow for cosmological conclusions. Alternative methods must be developed to study these issues further.
C1 Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway.
Max Planck Inst Astrophys, D-85741 Garching, Germany.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Warsaw Observ, PL-00478 Warsaw, Poland.
Univ Oslo, Ctr Math Applicat, N-0316 Oslo, Norway.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Eriksen, HK (reprint author), Univ Oslo, Inst Theoret Astrophys, POB 1029 Blindern, N-0315 Oslo, Norway.
EM h.k.k.eriksen@astro.uio.no; banday@mpa-garching.mpg.de;
krzysztof.m.gorski@jpl.nasa.gov; per.lilje@astro.uio.no
RI Lilje, Per/A-2699-2012;
OI Lilje, Per/0000-0003-4324-7794
NR 25
TC 137
Z9 138
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 10
PY 2004
VL 612
IS 2
BP 633
EP 646
DI 10.1086/422807
PN 1
PG 14
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 852XW
UT WOS:000223791100006
ER
PT J
AU Stern, D
van Dokkum, PG
Nugent, P
Sand, DJ
Ellis, RS
Sullivan, M
Bloom, JS
Frail, DA
Kneib, JP
Koopmans, LVE
Treu, T
AF Stern, D
van Dokkum, PG
Nugent, P
Sand, DJ
Ellis, RS
Sullivan, M
Bloom, JS
Frail, DA
Kneib, JP
Koopmans, LVE
Treu, T
TI Discovery of a transient U-band dropout in a Lyman break survey: A
tidally disrupted star at z=3.3?
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE galaxies : clusters : individual (A267); galaxies : high-redshift; stars
: flare; supernovae : general
ID ULTRAVIOLET LUMINOSITY DENSITY; HIGH-REDSHIFT SUPERNOVAE; SUPERMASSIVE
BLACK-HOLE; DIGITAL SKY SURVEY; IA SUPERNOVAE; SPECTROSCOPIC
CONFIRMATION; INFRARED-EMISSION; FORMING GALAXIES; ALPHA EMITTERS; MS
1512-CB58
AB We report the discovery of a transient source in the central regions of galaxy cluster A267. The object, which we call "PALS-1,'' was found in a survey aimed at identifying highly magnified Lyman break galaxies in the fields of intervening rich clusters. At discovery, the source had U(n)>24.7 (2 sigma; AB), g=21.96+/-0.12, and very blue g-r and r-i colors; i.e., PALS-1 was a "U-band dropout,'' characteristic of star-forming galaxies and quasars at zsimilar to3. However, 3 months later the source had faded by more than 3 mag. Further observations showed a continued decline in luminosity, to R>26.4 at 7 months after discovery. Although the apparent brightness suggests a supernova at roughly the cluster redshift, we show that the photometry and light curve argue against any known type of supernova at any redshift. The spectral energy distribution and location near the center of a galaxy cluster are consistent with the hypothesis that PALS-1 is a gravitationally lensed transient at zapproximate to3.3. If this interpretation is correct, the source is magnified by a factor of 4-7, and two counterimages are predicted. Our lens model predicts that there are time delays between the three images of 1-10 yr and that we have witnessed the final occurrence of the transient. The intense luminosity (M(AB)similar to-23.5 after correcting for lensing) and blue UV continuum (implying Tgreater than or similar to50,000 K) argue that the source may have been a flare resulting from the tidal disruption of a star by a 10(6)-10(8) M(circle dot) black hole. Regardless of its physical nature, PALS-1 highlights the importance of monitoring regions of high magnification in galaxy clusters for distant time-varying phenomena.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
CALTECH, Pasadena, CA 91125 USA.
Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA.
Univ Durham, Dept Phys, Durham DH1 3LE, England.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Natl Radio Astron Observ, Socorro, NM 87801 USA.
Observ Midi Pyrenees, Astrophys Lab, F-31400 Toulouse, France.
Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands.
Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
RP Stern, D (reprint author), CALTECH, Jet Prop Lab, MS 169-506, Pasadena, CA 91109 USA.
RI Kneib, Jean-Paul/A-7919-2015;
OI Kneib, Jean-Paul/0000-0002-4616-4989; Sullivan, Mark/0000-0001-9053-4820
NR 78
TC 19
Z9 19
U1 0
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 10
PY 2004
VL 612
IS 2
BP 690
EP 697
DI 10.1086/422744
PN 1
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 852XW
UT WOS:000223791100011
ER
PT J
AU Titarchuk, L
Fiorito, R
AF Titarchuk, L
Fiorito, R
TI Spectral index and quasi-periodic oscillation frequency correlation in
black hole sources: Observational evidence of two phases and phase
transition in black holes
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE black hole physics; stars : oscillations; X-rays : general
ID X-RAY BINARIES; MONTE-CARLO SIMULATIONS; NEUTRON-STAR BINARIES;
HIGH-ENERGY SPECTRA; NOVA XTE J1550-564; GRS 1915+105; POWER-LAW;
INTRINSIC SIGNATURE; MASS DETERMINATION; RXTE OBSERVATIONS
AB Recent studies have shown that strong correlations are observed between the low frequencies ( 1 - 10 Hz) of quasi-periodic oscillations (QPOs) and the spectral power law index of several black hole (BH) candidate sources, in low ( hard) states, steep power law ( soft) states, and transitions between these states. The observations indicate that the X-ray spectra of such state (phases) show the presence of a power-law component and are sometimes related to simultaneous radio emission, indicating the probable presence of a jet. Strong QPOs (> 20% rms) are present in the power density spectrum in the spectral range where the power-law component is dominant (i.e., 60% - 90%). This evidence contradicts the dominant, long-standing interpretation of QPOs as a signature of the thermal accretion disk. We present the data from the literature and our own data to illustrate the dominance of power-law index - QPO frequency correlations. We provide a model that identifies and explains the origin of the QPOs and how they are imprinted on the properties of the power-law flux component. We argue for the existence of a bounded compact coronal region that is a natural consequence of the adjustment of the Keplerian disk flow to the innermost sub-Keplerian boundary conditions near the central object and that ultimately leads to the formation of a transition layer (TL) between the adjustment radius and the innermost boundary. The model predicts two phases or states dictated by the photon upscattering produced in the TL: (1) a hard state, in which the TL is optically thin and very hot (kT greater than or similar to 50 keV), producing photon upscattering via thermal Comptonization ( the photon spectrum index Gamma similar to 1.7 for this state is dictated by gravitational energy release and Compton cooling in an optically thin shock near the adjustment radius), and ( 2) a soft state that is optically thick and relatively cold (kT less than or similar to 5 keV; the index for this state, Gamma similar to 2.8, is determined by soft-photon upscattering and photon trapping in a converging flow into the BH). In the TL model for the corona, the QPO frequency nu(high) is related to the gravitational (close to Keplerian) frequency nu(K) at the outer (adjustment) radius and nu(low) is related to the TL's normal mode (magnetoacoustic) oscillation frequency nu(MA). The observed correlations between index and low and high QPO frequencies are readily explained in terms of this model. We also suggest a new method for evaluation of the BH mass using the index-frequency correlation.
C1 George Mason Univ, Sch Comp Sci, Ctr Earth Observ & Space Res, Fairfax, VA 22030 USA.
USN, Res Lab, Washington, DC 20375 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Maryland, College Pk, MD 20742 USA.
RP Titarchuk, L (reprint author), George Mason Univ, Sch Comp Sci, Ctr Earth Observ & Space Res, Fairfax, VA 22030 USA.
EM lev.titarchuk@nrl.navy.mil; rfiorito@umd.edu
NR 63
TC 67
Z9 67
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 10
PY 2004
VL 612
IS 2
BP 988
EP 999
DI 10.1086/422573
PN 1
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 852XW
UT WOS:000223791100037
ER
PT J
AU Boyd, PT
Smale, AP
AF Boyd, PT
Smale, AP
TI The long-term light curves of X-ray binaries contain simultaneous
periodic and random components
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE accretion, accretion disks; binaries : close; stars : individual (Cygnus
X-2, Cygnus X-3, LMC X-3); X-rays : binaries
ID WARPED ACCRETION DISCS; SOURCE CYGNUS X-2; 35 DAY CYCLE; LMC X-3;
TIMING-EXPLORER; NEUTRON-STAR; BLACK-HOLE; SMC X-1; DISCOVERY; MASS
AB LMCX-3 and Cyg X-2 show large-amplitude X-ray fluctuations that have been attributed to a warped accretion disk. Cyg X-3 displays high-amplitude, apparently nonperiodic oscillations. We reanalyze these systems using RXTE ASM data and time-frequency decomposition techniques. We find that the long-term variations in Cyg X-2 can be completely characterized by excursions whose durations are integer multiples of the orbital period, including one essentially identical to the reported "period'' of 78 days. Cyg X-3 can be characterized in terms of integer multiples of a 71 day fundamental period, unrelated to the 4.8 day orbital period, but suggestively close to the greater than or similar to60 day reported precession period of the relativistic jet inferred from recent radio observations. The long-term excursions of LMC X-3 are related to each other by rational fractions, suggesting the characteristic timescale is 10.6 days, shorter than any observed excursion to date. We explore the phase-space evolution of the light curves, using a natural embedding, and find that all three systems possess two rotation centers that organize the phase-space trajectories, one of low luminosity and the other of high luminosity. The implications of this repeatable behavior on generic models of accretion disk dynamics and mass transfer variability are explored.
C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Baltimore, MD 21228 USA.
Univ Space Res Assoc, Columbia, MD 21044 USA.
RP Boyd, PT (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 662, Greenbelt, MD 20771 USA.
RI Boyd, Patricia/D-3274-2012
NR 57
TC 8
Z9 8
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 10
PY 2004
VL 612
IS 2
BP 1006
EP 1017
DI 10.1086/421078
PN 1
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 852XW
UT WOS:000223791100039
ER
PT J
AU Woo, R
Habbal, SR
Feldman, U
AF Woo, R
Habbal, SR
Feldman, U
TI Role of closed magnetic fields in solar wind flow
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE solar wind; Sun : abundances; Sun : corona; Sun : magnetic fields
ID UPPER-ATMOSPHERE; EMISSION-LINE; CORONA; SUN; POLARIZATION; INSTRUMENT;
ABUNDANCE; ULYSSES; SLOW
AB In this paper we demonstrate how closed magnetic fields appear to be playing a significant role in solar wind flow. Confinement or trapping of plasma is the physical process, while confinement duration, as characterized by the first ionization potential (FIP) bias, is the attribute that divides the fast- and slow-wind regions. The trapped plasma is released along ubiquitous and predominantly radial open field lines, presumably by continual reconnection at the base of the corona, with evidence for this process coming from the appearance of the imprint of polar coronal holes, quiet Sun, and active regions in the outer corona and interplanetary space. When trapping is not long enough to enrich the elemental abundance ( FIP bias near 1), the coronal radial density gradient is steep, coronal temperature is low, and a fast wind flows in the overlying corona. However, the presence of closed fields still influences the flow of the fast wind, as revealed by the fact that flow speed is anticorrelated with, or characterized by, the density at the base of the corona. When trapping is long enough to enrich the abundance (FIP bias > 1), a slow wind flows, and FIP bias characterizes its properties. Enhanced FIP bias gives rise to a decreased coronal radial density gradient, as manifested by the extension of coronal streamers in white-light coronal images, increased coronal temperature, and decreased solar wind speed in the overlying corona.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Wales, Aberystwyth SY23 3BZ, Dyfed, Wales.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
ARTEP Inc, Ellicott City, MD 21042 USA.
USN, Res Lab, EO Hulburt Ctr Space Res, Washington, DC 20375 USA.
RP Woo, R (reprint author), CALTECH, Jet Prop Lab, 1800 Oak Grove Dr,MS 238-725, Pasadena, CA 91109 USA.
EM richard.woo@jpl.nasa.gov; sdh@aber.ac.uk; uri.feldman@nrl.navy.mil
NR 28
TC 33
Z9 33
U1 1
U2 3
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 10
PY 2004
VL 612
IS 2
BP 1171
EP 1174
DI 10.1086/422799
PN 1
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 852XW
UT WOS:000223791100055
ER
PT J
AU Reynolds, RJ
Madsen, GJ
Moseley, SH
AF Reynolds, RJ
Madsen, GJ
Moseley, SH
TI New measurements of the motion of the zodiacal dust
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE interplanetary medium; line : profiles; scattering; solar system :
general
ID FRAUNHOFER LINE-PROFILES; RADIAL-VELOCITY MEASUREMENTS; DOPPLER SHIFTS;
LIGHT SPECTRUM; CLOUD; SCATTERING; PARTICLES; RING; ANGSTROM
AB Using the Wisconsin Halpha Mapper ( WHAM), we have measured at high spectral resolution and high signal-to-noise ratio the profile of the scattered solar Mg I lambda5184 Fraunhofer line in the zodiacal light. The observations were carried out toward 49 directions that sampled the ecliptic equator from solar elongations of 48degrees ( evening sky) to 334degrees ( morning sky) plus observations near + 47degrees and + 90degrees ecliptic latitude. The spectra show a clear prograde kinematic signature that is inconsistent with dust confined to the ecliptic plane and in circular orbits influenced only by the Sun's gravity. In particular, the broadened widths of the profiles, together with large amplitude variations in the centroid velocity with elongation angle, indicate that a significant population of dust is on eccentric orbits. In addition, the wide, flat-bottomed line profile toward the ecliptic pole indicates a broad distribution of orbital inclinations extending up to about 30degrees-40degrees with respect to the ecliptic plane. The absence of pronounced asymmetries in the shape of the profiles limits the retrograde population to less than 10% of the prograde population, and also places constraints on the scattering phase function of the particles. These results do not show the radial outflow or evening-morning velocity amplitude asymmetry reported in some earlier investigations. The reduction of the spectra included the discovery and removal of extremely faint, unidentified terrestrial emission lines that contaminate and distort the underlying Mg I profile. This atmospheric emission is too weak to have been seen in earlier, lower signal-to-noise ratio observations, but it probably affected the line centroid measurements of previous investigations.
C1 Univ Wisconsin, Dept Astron, Madison, WI 53706 USA.
NASA, Goddard Space Flight Ctr, Infrared Astrophys Branch, Greenbelt, MD 20771 USA.
RP Reynolds, RJ (reprint author), Univ Wisconsin, Dept Astron, 475 N Charter St, Madison, WI 53706 USA.
EM reynolds@astro.wisc.edu; madsen@astro.wisc.edu;
moseley@stars.gsfc.nasa.gov
RI Moseley, Harvey/D-5069-2012
NR 39
TC 13
Z9 14
U1 1
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 10
PY 2004
VL 612
IS 2
BP 1206
EP 1213
DI 10.1086/422798
PN 1
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 852XW
UT WOS:000223791100060
ER
PT J
AU Tran, KVH
Lilly, SJ
Crampton, D
Brodwin, M
AF Tran, KVH
Lilly, SJ
Crampton, D
Brodwin, M
TI A very large telescope FORS2 multislit search for Ly alpha-emitting
galaxies at z similar to 6.5
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE cosmology : observations; early universe; galaxies : evolution; galaxies
: formation
ID LYMAN BREAK GALAXIES; ORIGINS DEEP SURVEY; CLUSTERING PROPERTIES;
EMITTERS; FIELD; CONSTRAINTS; DISCOVERY
AB We present results from a deep spectroscopic search in the 9150 Angstrom atmospheric window for Lyalpha-emitting galaxies using the VLT/FORS2. Our multislit + narrowband filter survey covers a total spatial area of 17.6 arcmin(2) in four different fields and reaches fluxes down to 5 x 10(-18) ergs s(-1) cm(-2) (7 sigma detection). Our detection limit is significantly fainter than narrowband searches at this redshift and fainter also than the unlensed brightness of Hu et al.' s HCM 6A at z = 6.56, and thus it provides better overlap with surveys at much lower redshifts. Eighty secure emission-line galaxies are detected. However, based on their clear continuum emission shortward of the line or the presence of multiple lines, none of these can be Lyalpha emission at z similar to 6.5. Our null result of finding no z similar to 6.5 Lyalpha emitters suggests that the number density of Lyalpha emitters with Lgreater than or equal to2 x 10(42) ergs s(-1) declines by greater than or similar to2 between z similar to 3 and z similar to 6.5.
C1 ETH, Inst Astron, CH-8093 Zurich, Switzerland.
Herzberg Inst Astrophys, Victoria, BC V9E 2E7, Canada.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Tran, KVH (reprint author), ETH, Inst Astron, Scheuchzerstr 7, CH-8093 Zurich, Switzerland.
EM vy@phys.ethz.ch
NR 26
TC 27
Z9 27
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 10
PY 2004
VL 612
IS 2
BP L89
EP L92
DI 10.1086/424801
PN 2
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 852XX
UT WOS:000223791200001
ER
PT J
AU Greenblatt, D
Moss, EA
AF Greenblatt, D
Moss, EA
TI Rapid temporal acceleration of a turbulent pipe flow
SO JOURNAL OF FLUID MECHANICS
LA English
DT Article
ID RELAMINARIZATION; LAYER
AB Measurements were made of fully developed turbulent pipe flows subjected to temporal pressure gradients larger than those considered previously. Integral profile parameters exhibited similar qualitative trends when time was scaled with the flow rise time and this differed from corresponding spatial development of flows subjected to steady streamwise pressure gradients. Velocity profiles were initially characterized by significant reduction of their wake component. This was accompanied by turbulence intensity freezing in the core region of the pipe and a rapid turbulence increase in the near-wall region that propagated towards the pipe centre. The final phase of the acceleration was characterized by reconstitution of the wake, producing a velocity profile inflection and the generation of turbulence in that vicinity. These features were not observed in previous investigations, possibly due to the present use of higher ramp rates and initial Reynolds numbers.
C1 Univ Witwatersrand, Sch Mech Engn, ZA-2050 Wits, South Africa.
RP Greenblatt, D (reprint author), NASA, Langley Res Ctr, Flow Phys & Control Branch, Hampton, VA 23681 USA.
NR 10
TC 23
Z9 23
U1 0
U2 4
PU CAMBRIDGE UNIV PRESS
PI NEW YORK
PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA
SN 0022-1120
J9 J FLUID MECH
JI J. Fluid Mech.
PD SEP 10
PY 2004
VL 514
BP 65
EP 75
DI 10.1017/S0022112004000114
PG 11
WC Mechanics; Physics, Fluids & Plasmas
SC Mechanics; Physics
GA 858WR
UT WOS:000224223600003
ER
PT J
AU Knaepen, B
Debliquy, O
Carati, D
AF Knaepen, B
Debliquy, O
Carati, D
TI Direct numerical simulation and large-eddy simulation of a shear-free
mixing layer
SO JOURNAL OF FLUID MECHANICS
LA English
DT Article
ID TURBULENCE
AB High resolution direct numerical simulation (DNS) (512 x 1024 x 512) and large-eddy simulation (LES) of a shear-free mixing layer are presented. The geometry of the flow consists of two layers with different turbulence intensities that are in contact and interact through a fairly thin mixing layer. This geometry is used to explore the influence of inhomogeneities in the characteristic length scales, times scales and energy scales on the turbulence properties. Comparison of DNS results is made with the Veeravalli & Warhaft (J. Fluid Mech. 207, 191-229, 1989) experiment. The LES is performed on a 32 x 64 x 32 grid using an eddy-viscosity model. The use of such a model appears to be justified by the very weak departures from isotropy that are observed in the shear-free mixing layer. The LES predictions are compared with the filtered DNS data and show that the eddy viscosity model performs very well in predicting the energy profile as well as the deviation from Gaussianity in the turbulent velocity field statistics.
C1 Stanford Univ, NASA, Ames Res Ctr, Ctr Turbulence Res, Stanford, CA 94305 USA.
Free Univ Brussels, B-1050 Brussels, Belgium.
RP Knaepen, B (reprint author), Stanford Univ, NASA, Ames Res Ctr, Ctr Turbulence Res, 488 Escondido Mall,Bldg 500-500A, Stanford, CA 94305 USA.
NR 15
TC 11
Z9 12
U1 0
U2 4
PU CAMBRIDGE UNIV PRESS
PI NEW YORK
PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA
SN 0022-1120
J9 J FLUID MECH
JI J. Fluid Mech.
PD SEP 10
PY 2004
VL 514
BP 153
EP 172
DI 10.1017/S0022112004000035
PG 20
WC Mechanics; Physics, Fluids & Plasmas
SC Mechanics; Physics
GA 858WR
UT WOS:000224223600007
ER
PT J
AU Makarov, OP
Ajello, JM
Vattipalle, P
Kanik, I
Festou, MC
Bhardwaj, A
AF Makarov, OP
Ajello, JM
Vattipalle, P
Kanik, I
Festou, MC
Bhardwaj, A
TI Kinetic energy distributions and line profile measurements of
dissociation products of water upon electron impact
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
DE comets; ultraviolet spectroscopy; electron collisions; cross sections;
water
ID EMISSION CROSS-SECTIONS; JET-COOLED H2O; H-LYMAN-ALPHA; COMET HALLEY;
ULTRAVIOLET SPECTROMETER; ATOMIC-HYDROGEN; GIANT PLANETS; INNER COMA;
EXCITATION; H-2
AB [1] The Doppler line profiles of H Ly-alpha (1216 Angstrom) and O I (1302 Angstrom and 1152 Angstrom) resulting from electron impact dissociative excitation of H2O have been measured with a high-resolution (lambda/Deltalambda = 50,000) ultraviolet spectrometer. The line profiles are used to calculate the kinetic energy distribution of the hydrogen atoms produced in dissociative excitation and ionization of H2O at electron impact energies 25, 35, and 100 eV. Three distinct populations of H(2p) atoms were found. The kinetic energy of hydrogen atoms is found to have contributions from a low-energy component, with a mean energy of similar to 0.2 eV at all the three electron impact energies. In addition, a medium-energy component appears with a mean energy of similar to 2.0 eV for 35 eV electrons, and a high-energy component, similar to 7 eV, for 100 eV electrons. The measurement of O I (1302 Angstrom) and O I (1152 Angstrom) line profiles indicate that the kinetic energy of excited O I atoms is very small (similar to1 eV or less) at all electron impact energies. Most of the energy released in dissociation is found in the translational energy of the hydrogen atoms. The excitation functions of H Ly-alpha, O I (1302 Angstrom) feature of oxygen, and A(0) - X(0) molecular band of hydroxyl near 3050 Angstrom from threshold to 600 V were also measured. The spectrum (1.0 Angstrom FWHM) of the rotational structure of OH (A - X) from electron impact dissociation indicates a high degree of rotational excitation, which is almost identical to the rotational structure from dissociative recombination of H2O+. The results presented in this paper have important applications to planetary bodies, like comets, icy satellites of outer planets, Saturn's magnetosphere, and rings, all of which have H2O and its daughter products in large amount.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Observ Midi Pyrenees, F-31400 Toulouse, France.
Vikram Sarabhai Space Ctr, Space Phys Lab, Trivandrum 695022, Kerala, India.
RP Univ Connecticut, Dept Phys, Storrs, CT 06268 USA.
EM oleg.makarov@uconn.edu; jajello@pop.jpl.nasa.gov;
prahlad.vattipalle@jpl.nasa.gov; isik.kanik@jpl.nasa.gov;
festou@ast.obs-mip.fr; bhardwaj_spl@yahoo.com
OI Bhardwaj, Anil/0000-0003-1693-453X
NR 63
TC 16
Z9 16
U1 0
U2 6
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9380
EI 2169-9402
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD SEP 10
PY 2004
VL 109
IS A9
AR A09303
DI 10.1029/2002JA009353
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 854HO
UT WOS:000223893400001
ER
PT J
AU Kunde, VG
Flasar, FM
Jennings, DE
Bezard, B
Strobel, DF
Conrath, BJ
Nixon, CA
Bjoraker, GL
Romani, PN
Achterberg, RK
Simon-Miller, AA
Irwin, P
Brasunas, JC
Pearl, JC
Smith, MD
Orton, GS
Gierasch, PJ
Spilker, LJ
Carlson, RC
Mamoutkine, AA
Calcutt, SB
Read, PL
Taylor, FW
Fouchet, T
Parrish, P
Barucci, A
Courtin, R
Coustenis, A
Gautier, D
Lellouch, E
Marten, A
Prange, R
Biraud, Y
Ferrari, C
Owen, TC
Abbas, MM
Samuelson, RE
Raulin, F
Ade, P
Cesarsky, CJ
Grossman, KU
Coradini, A
AF Kunde, VG
Flasar, FM
Jennings, DE
Bezard, B
Strobel, DF
Conrath, BJ
Nixon, CA
Bjoraker, GL
Romani, PN
Achterberg, RK
Simon-Miller, AA
Irwin, P
Brasunas, JC
Pearl, JC
Smith, MD
Orton, GS
Gierasch, PJ
Spilker, LJ
Carlson, RC
Mamoutkine, AA
Calcutt, SB
Read, PL
Taylor, FW
Fouchet, T
Parrish, P
Barucci, A
Courtin, R
Coustenis, A
Gautier, D
Lellouch, E
Marten, A
Prange, R
Biraud, Y
Ferrari, C
Owen, TC
Abbas, MM
Samuelson, RE
Raulin, F
Ade, P
Cesarsky, CJ
Grossman, KU
Coradini, A
TI Jupiter's atmospheric composition from the Cassini thermal infrared
spectroscopy experiment
SO SCIENCE
LA English
DT Article
ID COMET SHOEMAKER-LEVY-9; JOVIAN SYSTEM; HCN; STRATOSPHERE; PRECIPITATION;
EXCITATION; VOYAGER-1; EVOLUTION; IMPACTS; IO
AB The Composite Infrared Spectrometer observed Jupiter in the thermal infrared during the swing-by of the Cassini spacecraft. Results include the detection of two new stratospheric species, the methyl radical and diacetylene, gaseous species present in the north and south auroral infrared hot spots; determination of the variations with latitude of acetylene and ethane, the latter a tracer of atmospheric motion; observations of unexpected spatial distributions of carbon dioxide and hydrogen cyanide, both considered to be products of comet Shoemaker-Levy 9 impacts; characterization of the morphology of the auroral infrared hot spot acetylene emission; and a new evaluation of the energetics of the northern auroral infrared hot spot.
C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Observ Paris, LESIA, CNRS, UMR8109, F-91925 Meudon, France.
Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA.
Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
Space Sci & Applicat Inc, Lanham, MD 20706 USA.
Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
CEA Saclay, Serv Astrophys, F-91191 Gif Sur Yvette, France.
Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
Univ Paris 07, LISA, CNRS, UMR 7583, F-94010 Creteil, France.
Univ Paris 12, LISA, CNRS, UMR 7583, F-94010 Creteil, France.
Cardiff Univ, Sch Phys & Astron, Cardiff CF24 3YB, S Glam, Wales.
European So Observ, D-85748 Garching, Germany.
Gesamthsch Wuppertal, Dept Phys, D-5600 Wuppertal 1, Germany.
CNR, Inst Astrophys Spatiale, Area Recerca Tor Vergata, I-00133 Rome, Italy.
RP Kunde, VG (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
EM Virgil.G.Kunde.1@gsfc.nasa.gov
RI Simon, Amy/C-8020-2012; Nixon, Conor/A-8531-2009; Ferrari,
Cecile/P-9735-2016; Fouchet, Thierry/C-6374-2017; Flasar, F
Michael/C-8509-2012; Smith, Michael/C-8875-2012; Romani,
Paul/D-2729-2012; Bjoraker, Gordon/D-5032-2012; Jennings,
Donald/D-7978-2012; brasunas, john/I-2798-2013
OI Simon, Amy/0000-0003-4641-6186; Nixon, Conor/0000-0001-9540-9121;
Ferrari, Cecile/0000-0001-5962-7439; Fouchet,
Thierry/0000-0001-9040-8285;
NR 38
TC 43
Z9 43
U1 2
U2 11
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
J9 SCIENCE
JI Science
PD SEP 10
PY 2004
VL 305
IS 5690
BP 1582
EP 1586
DI 10.1126/science.1100240
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 854GV
UT WOS:000223891200034
PM 15319491
ER
PT J
AU Barbieri, LP
Mahmot, RE
AF Barbieri, LP
Mahmot, RE
TI October-November 2003's space weather and operations lessons learned
SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
LA English
DT Article
DE space weather; operations; lessons learned; best practices;
environmental effects
AB The Sun-Earth space weather related to sunspots NOAA 484, 486, and 488 affected a number of NASA spacecraft and instruments between mid-October and early November 2003. Information available from Earth and space science missions indicate that about 59% of the spacecraft and about 18% of the instrument groups experienced some effect from the solar activity. This paper summarizes the impacts on spacecraft, instruments, and science data. The database that the paper is based on describes spacecraft and instrument effects observed as well as mission operators' preventive actions from 34 reporting missions. The database is Appendix A and provides additional material that could be of interest and that could be useful to satellite developers, operators, instrument managers, and scientists. The types of environmental effects observed were electronic upsets, housekeeping and science noise, proton degradation to solar arrays, upper atmosphere-induced changes to orbit dynamics, high levels of accumulated radiation, and proton heating. The paper develops best practices that are intended to foster continued and expanded feedback on the space environment in all mission phases, to promote designing to the mission's observing mode so that planning is appropriate to mission science goals, to distribute operational experience and lessons learned widely among both developing and operating missions, and to uniformly apply the developed knowledge base among NASA's missions.
C1 NASA, Goddard Space Flight Ctr, Space Sci Mission Operat Project, Greenbelt, MD 20771 USA.
RP Barbieri, LP (reprint author), NASA, Goddard Space Flight Ctr, Space Sci Mission Operat Project, Code 444,Bldg 3,Room 140, Greenbelt, MD 20771 USA.
EM lbarbieri@hst.nasa.gov; ronald.e.mahmot@nasa.gov
NR 2
TC 23
Z9 28
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 1542-7390
J9 SPACE WEATHER
JI Space Weather
PD SEP 10
PY 2004
VL 2
IS 9
AR S09002
DI 10.1029/2004SW000064
PG 15
WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology &
Atmospheric Sciences
GA 909HJ
UT WOS:000227850700001
ER
PT J
AU Shapiro, IR
Solares, SD
Esplandiu, MJ
Wade, LA
Goddard, WA
Collier, CP
AF Shapiro, IR
Solares, SD
Esplandiu, MJ
Wade, LA
Goddard, WA
Collier, CP
TI Influence of elastic deformation on single-wall carbon nanotube atomic
force microscopy probe resolution
SO JOURNAL OF PHYSICAL CHEMISTRY B
LA English
DT Article
ID SAMPLE INTERACTION REGIMES; DER-WAALS FORCES; SCANNING PROBE; TIP;
SURFACE; GROWTH
AB We have previously reported that 4-6 nm diameter single-wall carbon nanotube (SWNT) probes used for tapping-mode atomic force microscopy (AFM) can exhibit lateral resolution that is significantly better than the probe diameter when prone nanotubes are imaged on a flat SiO2 surface. To further investigate this phenomenon, accurate models for use in atomistic molecular dynamics simulations were constructed on the basis of transmission electron microscopy (TEM) and AFM data. Probe-sample interaction potentials were Generated by utilization of force fields derived from ab initio quantum mechanics calculations and material bulk and surface properties, and the resulting force curves were integrated numerically with the AFM cantilever equation of motion. The simulations demonstrate that, under the AFM imaging conditions employed, elastic deformations of both the probe and sample nanotubes result in a decrease of the apparent width of the sample. This behavior provides an explanation for the unexpected resolution improvement and illustrates some of the subtleties involved when imaging is performed with SWNT probes in place of conventional silicon probes. However, the generality of this phenomenon for other AFM imaging applications employing SWNT probes remains to be explored.
C1 CALTECH, Dept Chem, Pasadena, CA 91125 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA.
CALTECH, Dept Chem Engn, Pasadena, CA 91125 USA.
CALTECH, Dept Appl Phys, Pasadena, CA 91125 USA.
RP CALTECH, Dept Chem, Pasadena, CA 91125 USA.
EM wag@wag.caltech.edu; collier@caltech.edu
RI Esplandiu, Maria Jose/N-5770-2014
OI Esplandiu, Maria Jose/0000-0003-2079-0639
NR 33
TC 30
Z9 30
U1 2
U2 6
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 1520-6106
J9 J PHYS CHEM B
JI J. Phys. Chem. B
PD SEP 9
PY 2004
VL 108
IS 36
BP 13613
EP 13618
DI 10.1021/jp047937x
PG 6
WC Chemistry, Physical
SC Chemistry
GA 851RW
UT WOS:000223703900009
ER
PT J
AU Bergstrom, RW
Pilewskie, P
Pommier, J
Rabbette, M
Russell, PB
Schmid, B
Redemann, J
Higurashi, A
Nakajima, T
Quinn, PK
AF Bergstrom, RW
Pilewskie, P
Pommier, J
Rabbette, M
Russell, PB
Schmid, B
Redemann, J
Higurashi, A
Nakajima, T
Quinn, PK
TI Spectral absorption of solar radiation by aerosols during ACE-Asia
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE light absorption; single-scattering albedo; ACE-Asia aerosols
ID SINGLE-SCATTERING ALBEDO; EAST CHINA SEA; OPTICAL-PROPERTIES; COLUMN
CLOSURE; WATER-VAPOR; SAFARI 2000; IN-SITU; VARIABILITY; PARTICLES; DUST
AB As part of the Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia), the upward and downward spectral solar radiant fluxes were measured with the Spectral Solar Flux Radiometer (SSFR), and the aerosol optical depth was measured with the Ames Airborne Tracking Sunphotometer (AATS-14) aboard the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter aircraft. In this paper, we examine the data obtained for two cases: a moderately thick aerosol layer, 12 April, and a relatively thin aerosol case, 16 April 2001. On both days, the Twin Otter flew vertical profiles in the Korean Strait southeast of Gosan Island. For both days we determine the aerosol spectral absorption of the layer and estimate the spectral aerosol absorption optical depth and single-scattering albedo. The results for 12 April show that the single-scattering albedo increases with wavelength from 0.8 at 400 nm to 0.95 at 900 nm and remains essentially constant from 950 to 1700 nm. On 16 April the amount of aerosol absorption was very low; however, the aerosol single-scattering albedo appears to decrease slightly with wavelength in the visible region. We interpret these results in light of the two absorbing aerosol species observed during the ACE-Asia study: mineral dust and black carbon. The results for 12 April are indicative of a mineral dust-black carbon mixture. The 16 April results are possibly caused by black carbon mixed with nonabsorbing pollution aerosols. For the 12 April case we attempt to estimate the relative contributions of the black carbon particles and the mineral dust particles. We compare our results with other estimates of the aerosol properties from a Sea-Viewing Wide Field-of View Sensor (SeaWiFS) satellite analysis and aerosol measurements made aboard the Twin Otter, aboard the National Oceanic and Atmospheric Administration Ronald H. Brown ship, and at ground sites in Gosan and Japan. The results indicate a relatively complicated aerosol mixture of both industrial pollution ( including black carbon) and mineral dust. This underscores the need for careful measurements and analysis to separate out the absorption effects of mineral dust and black carbon in the east Asia region.
C1 Bay Area Environm Res Inst, Sonoma, CA 95476 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Natl Inst Environm Studies, Tsukuba, Ibaraki 3058506, Japan.
Univ Tokyo, Ctr Climate Syst Res, Meguro Ku, Tokyo 1538904, Japan.
NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA.
RP Bay Area Environm Res Inst, 560 3rd St W, Sonoma, CA 95476 USA.
EM bergstrom@baeri.org; ppilewskie@mail.arc.nasa.gov;
jpommier@mail.arc.nasa.gov; mrabbette@mail.arc.nasa.gov;
philip.b.russell@nasa.gov; bschmid@mail.arc.nasa.gov;
redemann@atmos.ucla.edu; hakiko@nies.go.jp; teruyuki@ccsr.u-tokyo.ac.jp;
quinn@pmel.noaa.gov
RI Nakajima, Teruyuki/H-2370-2013; Quinn, Patricia/R-1493-2016
OI Nakajima, Teruyuki/0000-0002-9042-504X; Quinn,
Patricia/0000-0003-0337-4895
NR 38
TC 33
Z9 33
U1 0
U2 6
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 8
PY 2004
VL 109
IS D19
AR D19S15
DI 10.1029/2003JD004467
PG 13
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 854HG
UT WOS:000223892500001
ER
PT J
AU Hallar, AG
Avallone, LM
Herman, RL
Anderson, BE
Heymsfield, AJ
AF Hallar, AG
Avallone, LM
Herman, RL
Anderson, BE
Heymsfield, AJ
TI Measurements of ice water content in tropopause region arctic cirrus
during the SAGE III Ozone Loss and Validation Experiment (SOLVE)
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE ice water content; cirrus; heterogeneous chemistry
ID IN-SITU MEASUREMENTS; LARGE HNO3-CONTAINING PARTICLES; POLAR
STRATOSPHERIC CLOUDS; LOWERMOST STRATOSPHERE; MICROPHYSICAL PROPERTIES;
CHLORINE ACTIVATION; REACTIVE NITROGEN; EASTERN CANADA; HNO3;
TEMPERATURE
AB [1] A new instrument, the closed-path laser hygrometer (CLH), was flown on the NASA DC-8 aircraft during the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment ( SOLVE) campaign in 1999 - 2000 to measure condensed-phase water. The ice water content (IWC) of Arctic cirrus was determined from in situ measurements of condensed- and gas-phase water. The IWC values obtained from the CLH observations are compared to those determined by integrating particle size distributions measured by a Forward Scattering Spectrometer Probe (FSSP) also flown on the DC-8. The considerably greater IWC seen by the CLH implies the presence of particles with diameters greater than the FSSP's upper limit of 20 mm. The evidence for and implications of the presence of large ice crystals in Arctic cirrus is discussed.
C1 Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Natl Ctr Atmospher Res, Boulder, CO 80307 USA.
RP NASA, Ames Res Ctr, Stanford, CA 94035 USA.
EM avallone@lasp.colorado.edu
RI Heymsfield, Andrew/E-7340-2011; Herman, Robert/H-9389-2012; Hallar, Anna
Gannet/I-9104-2012
OI Herman, Robert/0000-0001-7063-6424; Hallar, Anna
Gannet/0000-0001-9972-0056
NR 54
TC 17
Z9 18
U1 0
U2 4
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 8
PY 2004
VL 109
IS D17
AR D17203
DI 10.1029/2003JD004348
PG 9
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 854HD
UT WOS:000223892200001
ER
PT J
AU Ridley, B
Ott, L
Pickering, K
Emmons, L
Montzka, D
Weinheimer, A
Knapp, D
Grahek, F
Li, L
Heymsfield, G
McGill, M
Kucera, P
Mahoney, MJ
Baumgardner, D
Schultz, M
Brasseur, G
AF Ridley, B
Ott, L
Pickering, K
Emmons, L
Montzka, D
Weinheimer, A
Knapp, D
Grahek, F
Li, L
Heymsfield, G
McGill, M
Kucera, P
Mahoney, MJ
Baumgardner, D
Schultz, M
Brasseur, G
TI Florida thunderstorms: A faucet of reactive nitrogen to the upper
troposphere
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE NOx; nitric oxide; lightning; convection; thunderstorms
ID LIGHTNING-PRODUCED NOX; MESOSCALE CONVECTIVE COMPLEX; OPTICAL TRANSIENT
DETECTOR; CHEMICAL-TRANSPORT MODEL; JULY 10; NORTHERN MIDLATITUDES;
NUMERICAL SIMULATIONS; TROPOPAUSE REGION; STERAO-A; OZONE
AB [1] During the July 2002 Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE), flights of a WB-57F aircraft revealed mixing ratios of nitric oxide 10 - 50 times background over distances of 25 - 175 km in the anvils of thunderstorms and in clear air downwind of storm systems due to lightning activity and possible transport from the boundary layer. Estimates of the total mass of NOx injected into the middle and upper troposphere differed considerably for a moderately versus highly electrically active storm system as expected. However, assuming that the total mass is dominated by lightning production, rough estimates of the production per average lightning flash for a moderately and a highly active storm also yielded quite different ranges of (0.33 - 0.66) x 10(26) and (1.7 - 2.3) x 10(26) molecules NO/flash, respectively. If the common assumption is made that intracloud flashes have 1/10th the NO production efficiency of cloud-to-ground (CG) flashes, the ranges of production for the moderately and highly active storms were (0.88 - 1.8) x 10(26) and (4.5 - 6.1) x 10(26) molecules NO/CG flash, respectively. The observed CG flash accumulations and NOx mass production estimate for the month of July 2002 over the Florida area are compared with results from the MOZART-2 global chemistry-transport model that uses a common lightning flash parameterization. Reasonable agreement was found after a correction to the lightning parameterization was made. Finally, broad-scale median mixing ratios of NO within anvils over Florida were significantly larger than found in storms previously investigated over Colorado and New Mexico.
C1 Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA.
Univ Nacl Autonoma Mexico, Ctr Ciencias Atmosfera, Mexico City 04510, DF, Mexico.
Max Planck Inst Meteorol, D-20146 Hamburg, Germany.
NASA, Goddard Space Flight Ctr, Mesoscale Atmospher Proc Branch, Greenbelt, MD 20771 USA.
Univ N Dakota, Dept Atmospher Sci, Grand Forks, ND 58202 USA.
Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA.
RP Natl Ctr Atmospher Res, Div Atmospher Chem, POB 3000, Boulder, CO 80307 USA.
EM ridley@ucar.edu; leo@atmos.umd.edu; pickerin@atmos.umd.edu;
emmons@ucar.edu; montzka@ucar.edu; wein@ucar.edu; dave@ucar.edu;
knarf@ucar.edu; lihua@agnes.gsfc.nasa.gov;
heymsfield@agnes.gsfc.nasa.gov; mcgill@agnes.gsfc.nasa.gov;
pkucera@aero.und.edu; michael.j.mahoney@jpl.nasa.gov;
darrel@servidor.unam.mx; schultz@dkrz.de; brasseur@dkrz.de
RI McGill, Matthew/D-8176-2012; Ott, Lesley/E-2250-2012; Pickering,
Kenneth/E-6274-2012; Emmons, Louisa/R-8922-2016; Schultz,
Martin/I-9512-2012
OI Emmons, Louisa/0000-0003-2325-6212; Schultz, Martin/0000-0003-3455-774X
NR 61
TC 43
Z9 44
U1 0
U2 8
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
EI 2169-8996
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 8
PY 2004
VL 109
IS D17
AR D17305
DI 10.1029/2004JD004769
PG 19
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 854HD
UT WOS:000223892200005
ER
PT J
AU Saetre, C
Stadsnes, J
Nesse, H
Aksnes, A
Petrinec, SM
Barth, CA
Baker, DN
Vondrak, RR
Ostgaard, N
AF Saetre, C
Stadsnes, J
Nesse, H
Aksnes, A
Petrinec, SM
Barth, CA
Baker, DN
Vondrak, RR
Ostgaard, N
TI Energetic electron precipitation and the NO abundance in the upper
atmosphere: A direct comparison during a geomagnetic storm
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
DE PIXIE; SNOE; nitric oxide; electron precipitation
ID THERMOSPHERIC NITRIC-OXIDE; X-RAYS; STRATOSPHERE; MESOSPHERE; TRANSPORT;
REGION; MODEL; PIXIE; SNOE; UV
AB Nitric oxide (NO) densities at heights between 96 and 150 km in the Earth's upper atmosphere are directly compared with the energy deposition from precipitating energetic electrons. The comparisons are done for the beginning of a geomagnetic storm event on 2 May 1998. The electron energy is derived from X-ray bremsstrahlung observations from the Polar Ionospheric X-ray Imaging Experiment (PIXIE) on board the Polar spacecraft. Measurements of the NO density are performed by the Student Nitric Oxide Explorer (SNOE) on the dayside by measuring airglow spectral features of the NO gamma-band. Since a significant part of the electron precipitation takes place during the night, and considering the long lifetime of NO, we have accumulated the X-ray data in geographical boxes. This enables us to follow the development of the total energy deposition over a specific area during the night and morning hours. In agreement with theoretical predictions we find an increase in NO at higher latitudes due to electron precipitation. At 106 km altitude, which is found to be the average altitude of the peak values of both NO intensity and precipitating electron energy, similar to83% of the NO density is produced by electron precipitation. At this altitude we find that the electron precipitation results in the production of similar to8 NO molecules per keV deposited energy. The comparison of the data also shows effects of a horizontal neutral wind. Above 100 km the peak in NO density is displaced equatorward of the peak in electron energy deposition.
C1 Univ Bergen, Dept Phys & Technol, N-5007 Bergen, Norway.
Atmospher & Space Phys Lab, Boulder, CO 80303 USA.
Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
Lockheed Martin, Ctr Adv Technol, Palo Alto, CA 94304 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Saetre, C (reprint author), Univ Bergen, Dept Phys & Technol, Allegaten 55, N-5007 Bergen, Norway.
EM camilla.satre@ift.uib.no; johan.stadsnes@ift.uib.no;
hilde.nesse@ift.uib.no; arve.aksnes@ift.uib.no;
petrinec@mail.spasci.com; charles.barth@lasp.colorado.edu;
baker@lasp.colorado.edu; richard.vondrak@gsfc.nasa.gov;
nikost@ssl.berkeley.edu
NR 30
TC 12
Z9 12
U1 0
U2 2
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD SEP 8
PY 2004
VL 109
IS A9
AR A09302
DI 10.1029/2004JA010485
PG 9
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 854HN
UT WOS:000223893200002
ER
PT J
AU Yang, JH
Dass, A
Rawashdeh, AMM
Sotiriou-Leventis, C
Panzner, MJ
Tyson, DS
Kinder, JD
Leventis, N
AF Yang, JH
Dass, A
Rawashdeh, AMM
Sotiriou-Leventis, C
Panzner, MJ
Tyson, DS
Kinder, JD
Leventis, N
TI Arylethynyl substituted 9,10-anthraquinones: Tunable Stokes shifts by
substitution and solvent polarity
SO CHEMISTRY OF MATERIALS
LA English
DT Article
ID INFRARED ABSORBING DYES; ELECTRONIC-ABSORPTION; TERMINAL ALKYNES;
FLUORESCENCE; DERIVATIVES; STATE; PHOTOCHEMISTRY; ANTHRAQUINONES;
PHOTOREDUCTION; PHOTOPHYSICS
AB 2-Arylethynyl- and 2,6- and 2,7-diarylethynyl-substituted 9,10-anthraquinones were synthesized via Sonogashira coupling reactions of 2-bromo-, 2,6-dibromo-, and 2,7-dibromo-9,10-anthraquinone with para-substituted phenylacetylenes. While the redox properties of those compounds are almost insensitive to substitution, their absorption maxima are linearly related to the Hammett constants with different slopes for electron donors and electron acceptors. All compounds are photoluminescent both in solution (quantum yields of emission less than or equal to 6%), and as solids. The emission spectra have the characteristics of charge-transfer bands with large Stokes shifts (100-250 nm). The charge-transfer character of the emitting state is supported by large dipole moment differences between the ground and the excited state as concluded on the basis of molecular modeling and Lippert-Mataga correlations of the Stokes shifts with solvent polarity. Maximum Stokes shifts are attained by both electron-donating and -withdrawing groups. This is explained by a destabilization of the HOMO by electron donors and a stabilization of the LUMO by electron acceptors. X-ray crystallographic analysis of, for example, 2,7-bisphenylethynyl-9, 10-anthraquinone reveals a monoclinic P2(1)/n space group and no indication for pi-overlap that would promote quenching, thus explaining emission from the solid state. Representative reduced forms of the title compounds were isolated as stable acetates of the corresponding dihydro-9,10-anthraquinones. The emission of these compounds is blue-shifted relative to the parent oxidized forms and is attributed to internal transitions in the dihydro-9,10-anthraquinone core.
C1 Univ Missouri, Dept Chem, Rolla, MO 65409 USA.
Univ Akron, Dept Chem, Akron, OH 44325 USA.
Ohio Aerosp Inst, Cleveland, OH 44142 USA.
NASA, Glenn Res Ctr, Div Mat, Cleveland, OH 44135 USA.
RP Leventis, N (reprint author), Univ Missouri, Dept Chem, Rolla, MO 65409 USA.
EM Nicholas.Leventis@nasa.gov
RI Dass, Amal/A-2520-2011; Dass, Amala/H-4729-2012
OI Dass, Amala/0000-0001-6942-5451
NR 43
TC 30
Z9 31
U1 2
U2 21
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 0897-4756
J9 CHEM MATER
JI Chem. Mat.
PD SEP 7
PY 2004
VL 16
IS 18
BP 3457
EP 3468
DI 10.1021/cm049590g
PG 12
WC Chemistry, Physical; Materials Science, Multidisciplinary
SC Chemistry; Materials Science
GA 852AX
UT WOS:000223728700012
ER
PT J
AU Nieto, MM
Turyshev, SG
AF Nieto, MM
Turyshev, SG
TI Finding the origin of the Pioneer anomaly
SO CLASSICAL AND QUANTUM GRAVITY
LA English
DT Article
ID SOLAR SAIL; MISSION; EXPLANATION
AB Analysis of radio-metric tracking data from the Pioneer 10/11 spacecraft at distances between 20 and 70 astronomical units (AU) from the Sun has consistently indicated the presence of an anomalous, small, constant Doppler frequency drift. The drift can be interpreted as being due to a constant acceleration of a(P) = (8.74 +/- 1.33) x 10(-8) cm s(-2) directed towards the Sun. Although it is suspected that there is a systematic origin to the effect, none has been found. As a result, the nature of this anomaly has become of growing interest. Here we present a concept for a deep-space experiment that will reveal the origin of the discovered anomaly and will also characterize its properties to an accuracy of at least two orders of magnitude below the anomaly's size. The proposed mission will not only provide a significant accuracy improvement in the search for small anomalous accelerations, it will also determine if the anomaly is due to some internal systematic or has an external origin. A number of critical requirements and design considerations for the mission are outlined and addressed. If only already existing technologies were used, the mission could be flown as early as 2010.
C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Los Alamos Natl Lab, Div Theoret, MS-B285, Los Alamos, NM 87545 USA.
EM mmn@lanl.gov; turyshev@jpl.nasa.gov
NR 25
TC 37
Z9 37
U1 2
U2 4
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0264-9381
EI 1361-6382
J9 CLASSICAL QUANT GRAV
JI Class. Quantum Gravity
PD SEP 7
PY 2004
VL 21
IS 17
BP 4005
EP 4023
AR PII S0264-9381(04)72106-1
DI 10.1088/026409381/21/17/001
PG 19
WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles
& Fields
SC Astronomy & Astrophysics; Physics
GA 859TH
UT WOS:000224290300003
ER
PT J
AU Manley, S
Cipelletti, L
Trappe, V
Bailey, AE
Christianson, RJ
Gasser, U
Prasad, V
Segre, PN
Doherty, MP
Sankaran, S
Jankovsky, AL
Shiley, B
Bowen, J
Eggers, J
Kurta, C
Lorik, T
Weitz, DA
AF Manley, S
Cipelletti, L
Trappe, V
Bailey, AE
Christianson, RJ
Gasser, U
Prasad, V
Segre, PN
Doherty, MP
Sankaran, S
Jankovsky, AL
Shiley, B
Bowen, J
Eggers, J
Kurta, C
Lorik, T
Weitz, DA
TI Limits to gelation in colloidal aggregation
SO PHYSICAL REVIEW LETTERS
LA English
DT Article
ID KINETIC AGGREGATION; CLUSTER AGGREGATION; DYNAMICS
AB We show that the dynamics of large fractal colloid aggregates are well described by a combination of translational and rotational diffusion and internal elastic fluctuations, allowing both the aggregate size and internal elasticity to be determined by dynamic light scattering. The comparison of results obtained in microgravity and on Earth demonstrates that cluster growth is limited by gravity-induced restructuring. In the absence of gravity, thermal fluctuations ultimately inhibit fractal growth and set the fundamental limitation to the lowest volume fraction which will gel.
C1 Harvard Univ, Dept Phys, Cambridge, MA 02138 USA.
Harvard Univ, DEAS, Cambridge, MA 02138 USA.
Univ Fribourg, Dept Phys, CH-1700 Fribourg, Switzerland.
NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
Zin Technol Inc, Brookpark, OH 44142 USA.
RP Manley, S (reprint author), Univ Montpellier 2, GDPC CC 26,PE Bataillon, F-34000 Montpellier, France.
RI Manley, Suliana/D-3818-2012; Sankaran, Subramanian/L-8416-2013
OI Manley, Suliana/0000-0002-4755-4778; Sankaran,
Subramanian/0000-0002-8990-4107
NR 16
TC 45
Z9 45
U1 2
U2 25
PU AMERICAN PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 0031-9007
J9 PHYS REV LETT
JI Phys. Rev. Lett.
PD SEP 3
PY 2004
VL 93
IS 10
AR 108302
DI 10.1103/PhysRevLett.93.108302
PG 4
WC Physics, Multidisciplinary
SC Physics
GA 851WQ
UT WOS:000223717600075
PM 15447462
ER
PT J
AU Fortney, JJ
AF Fortney, JJ
TI Looking into the giant planets
SO SCIENCE
LA English
DT Editorial Material
ID EQUATION-OF-STATE; PHASE-SEPARATION; HELIUM; JUPITER; SATURN; DEUTERIUM;
EVOLUTION; HYDROGEN
C1 NASA, Planetary Syst Branch, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Fortney, JJ (reprint author), NASA, Planetary Syst Branch, Ames Res Ctr, Moffett Field, CA 94035 USA.
EM jfortney@arc.nasa.gov
OI Fortney, Jonathan/0000-0002-9843-4354
NR 15
TC 7
Z9 7
U1 1
U2 2
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
J9 SCIENCE
JI Science
PD SEP 3
PY 2004
VL 305
IS 5689
BP 1414
EP 1415
DI 10.1126/science.1101352
PG 2
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 852NK
UT WOS:000223761900033
PM 15353790
ER
PT J
AU Bograd, SJ
Foley, DG
Schwing, FB
Wilson, C
Laurs, RM
Polovina, JJ
Howell, EA
Brainard, RE
AF Bograd, SJ
Foley, DG
Schwing, FB
Wilson, C
Laurs, RM
Polovina, JJ
Howell, EA
Brainard, RE
TI On the seasonal and interannual migrations of the transition zone
chlorophyll front
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID NORTH PACIFIC-OCEAN; WIND STRESS; TEMPERATURE; NUTRIENTS; DYNAMICS;
CLIMATE; SHIFTS; MODEL; GYRE
AB High-resolution satellite measurements of ocean color and surface winds, along with historical in situ data, are used to explore interannual variability in the annual migration of the transition zone chlorophyll front (TZCF) in the central North Pacific Ocean. Significant variations in frontal position and annual range were observed, including a significant southerly displacement during El Nino events. This displacement, apparently forced by enhanced surface convergence and vertical mixing in the transition zone, creates vast regions of anomalously high wintertime surface chlorophyll in the North Pacific Subtropical Gyre. A remarkably close correspondence between the positions of the TZCF and the 18degreesC surface isotherm over a portion of the central North Pacific allows historical temperature data to be used as a proxy for TZCF position. This surface temperature proxy has revealed decadal-scale variability in frontal position, with greater (lesser) annual range and southerly extent following the large-scale 1976-77 (1998-99) climate shifts. Interannual variations in TZCF position could have important implications for the distribution and survival of a number of apex predators that utilize the TZCF as a migratory and foraging habitat.
C1 NOAA, Pacific Marine Environm Lab, Natl Marine Fisheries Serv, Pacific Grove, CA 93950 USA.
NOAA, Pacific Isl Fisheries Sci Ctr, Natl Marine Fisheries Serv, Honolulu, HI 96822 USA.
Univ Hawaii, Inst Marine & Atmospher Res, Honolulu, HI 96822 USA.
RP Bograd, SJ (reprint author), NOAA, Pacific Marine Environm Lab, Natl Marine Fisheries Serv, 1352 Lighthouse Ave, Pacific Grove, CA 93950 USA.
EM sbograd@pfeg.noaa.gov
RI Wilson, Cara/A-8816-2009;
OI Howell, Evan/0000-0001-9904-4633
NR 19
TC 59
Z9 62
U1 1
U2 12
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD SEP 2
PY 2004
VL 31
IS 17
AR L17204
DI 10.1029/2004GL020637
PG 5
WC Geosciences, Multidisciplinary
SC Geology
GA 854FX
UT WOS:000223888200003
ER
PT J
AU Al-Saadi, JA
Pierce, RB
Natarajan, M
Fairlie, TD
Grose, WL
AF Al-Saadi, JA
Pierce, RB
Natarajan, M
Fairlie, TD
Grose, WL
TI Chemical climatology of the middle atmosphere simulated by the NASA
Langley Research Center Interactive Modeling Project for Atmospheric
Chemistry and Transport (IMPACT) model
SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
LA English
DT Article
DE general circulation model (GCM); middle atmosphere chemistry; middle
atmosphere composition
ID HALOGEN OCCULTATION EXPERIMENT; LOWER STRATOSPHERE; NITRIC-ACID;
INTERANNUAL VARIABILITY; ARCTIC STRATOSPHERE; UARS PLATFORM; POLAR
WINTER; OZONE; VALIDATION; NITROGEN
AB [ 1] The stratospheric chemical characteristics of the NASA Langley Research Center Interactive Modeling Project for Atmospheric Chemistry and Transport model are evaluated. We focus on species relevant to stratospheric ozone including the main constituents of the odd nitrogen and inorganic chlorine families. Model-derived chemical climatologies resulting from 20 years of integrations are compared with observations made primarily by the experiments aboard the Upper Atmosphere Research Satellite. The role of model transport characteristics in determining long-lived tracer distributions is assessed. The model is shown to reproduce observed distributions and seasonal variations of constituents throughout the middle stratosphere. Causes of biases in the upper and lower stratosphere are identified and discussed. In accord with recent observationally based studies, the fundamental coupling between tropospheric wave forcing and stratospheric ozone anomalies is shown to be reproduced by the model.
C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Al-Saadi, JA (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA.
EM j.a.al-saadi@nasa.gov
RI Pierce, Robert Bradley/F-5609-2010
OI Pierce, Robert Bradley/0000-0002-2767-1643
NR 72
TC 3
Z9 3
U1 0
U2 0
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-897X
J9 J GEOPHYS RES-ATMOS
JI J. Geophys. Res.-Atmos.
PD SEP 2
PY 2004
VL 109
IS D17
AR D17301
DI 10.1029/2003JD004354
PG 22
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 854GC
UT WOS:000223888700001
ER
PT J
AU Pimentel, AS
Payne, WA
Nesbitt, FL
Cody, RJ
Stief, LJ
AF Pimentel, AS
Payne, WA
Nesbitt, FL
Cody, RJ
Stief, LJ
TI Rate constant for the reaction H+C2H5 at T=150-295 K
SO JOURNAL OF PHYSICAL CHEMISTRY A
LA English
DT Article
ID METHYL RADICALS; HYDROGEN-ATOMS; TEMPERATURE-DEPENDENCE; ETHYLPEROXY
RADICALS; ETHYL RADICALS; SELF-REACTION; DIODE-LASER; KINETICS;
PHOTOCHEMISTRY; ETHANE
AB The reaction between the hydrogen atom and the ethyl (C2H5) radical is predicted by photochemical modeling to be the most important loss process for C2H5 radicals in the atmospheres of Jupiter and Saturn. This reaction is also one of the major sources for the methyl radicals in these atmospheres. These two simplest hydrocarbon radicals are the initial species for the synthesis of larger hydrocarbons. Previous measurements of the rate constant for the H + C2H5 (1) reaction varied by a factor of 5 at room temperature, and some studies showed a dependence upon temperature while others showed no such dependence. In addition, the previous studies were at higher temperatures and generally higher pressures than that needed for use in planetary atmospheric models. The rate constant for the reaction H + C2H5 has been measured directly at T = 150, 202, and 295 K and at P = 1.0 Torr He for all temperatures, and additionally at P = 0.5 and 2.0 Torr He at T = 202 K. The measurements were performed in a discharge-fast flow system. The decay of the C2H5 radical in the presence of excess hydrogen was monitored by low-energy electron impact mass spectrometry under pseudo-first-order conditions. H atoms and C2H5 radicals were generated rapidly and simultaneously by the reaction of fluorine atoms with H-2 and C2H6, respectively. The total rate constant was found to be temperature and pressure independent. The measured total rate constants at each temperature are: k(1)(295 K) = (1.06 +/- 0.25) x 10(-10), k(1)(202 K) = (1.05 +/- 0.23) x 10(-10), and k(1)(150 K) = (0.94 +/- 0.21) x 10(-10), all in units of cm(3) molecule(-1) s(-1). The total rate constant derived from all the combined measurements is k(1) = ( 1.07 +/- 0.18 ) x 10(-10) cm(3) molecule(-1) s(-1). At room-temperature our results are about a factor of 2 higher than the recommended rate constant and a factor of 3 lower than the most recently published study.
C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA.
Catholic Univ Amer, Dept Chem, Washington, DC 20064 USA.
RP Cody, RJ (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA.
EM Regina.Cody@nasa.gov
RI Pimentel, Andre/B-1278-2010; Cody, Regina/D-5996-2013;
OI Pimentel, Andre/0000-0002-1301-0561
NR 36
TC 6
Z9 6
U1 0
U2 3
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 1089-5639
J9 J PHYS CHEM A
JI J. Phys. Chem. A
PD SEP 2
PY 2004
VL 108
IS 35
BP 7204
EP 7210
DI 10.1021/jp0404204s
PG 7
WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical
SC Chemistry; Physics
GA 850HB
UT WOS:000223600700011
ER
PT J
AU Park, MA
AF Park, MA
TI Adjoint-based, three-dimensional error prediction and grid adaptation
SO AIAA JOURNAL
LA English
DT Article; Proceedings Paper
CT AIAA 32nd Fluid Dynamics Conference
CY JUN 24-26, 2002
CL St Louis, MO
SP Amer Inst Aeronaut & Astronaut
ID AERODYNAMIC DESIGN OPTIMIZATION; FUNCTIONAL OUTPUTS; UNSTRUCTURED GRIDS;
TURBULENT FLOWS; MESHES; ALGORITHM; COMPUTATIONS; GENERATION; EQUATIONS;
IMPLICIT
AB Engineering computational fluid dynamics analysis and design applications often focus on output functions, such as lift or drag. Errors in these output functions are generally unknown, and conservatively accurate solutions may be computed. Computable error estimates can offer the possibility to minimize computational work for a prescribed error tolerance. Such an estimate can be computed by solution of the flow equations and the linear adjoint problem for the functional of interest. The computational mesh can be modified to minimize the uncertainty of a computed error estimate. This robust mesh-adaptation procedure automatically terminates when the simulation is within a user-specified error tolerance. This procedure for estimation and adaptation to error in a functional is demonstrated for three-dimensional Euler problems. An adaptive mesh procedure that links to a CAD surface representation is demonstrated for wing, wing-body, and extruded high lift airfoil configurations. The error estimation and adaptation procedure yielded corrected functions that are as. accurate as functions calculated on uniformly refined grids with many more grid points.
C1 NASA Langley Res Ctr, Hampton, VA USA.
RP Park, MA (reprint author), NASA Langley Res Ctr, Hampton, VA USA.
EM A.Park@NASA.Gov
NR 33
TC 13
Z9 14
U1 0
U2 1
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0001-1452
J9 AIAA J
JI AIAA J.
PD SEP
PY 2004
VL 42
IS 9
BP 1854
EP 1862
DI 10.2514/1.10051
PG 9
WC Engineering, Aerospace
SC Engineering
GA 854TG
UT WOS:000223925600016
ER
PT J
AU Liu, T
AF Liu, T
TI Geometric and kinematic aspects of image-based measurements of
deformable bodies
SO AIAA JOURNAL
LA English
DT Article
ID OPTICAL-FLOW; VELOCIMETRY
AB From the viewpoint of an experimental fluid dynamicist, theoretical foundations of,quantitative image-based measurements for extracting geometric and kinematic properties of deformable bodies like fluids are discussed. New results are obtained by using a combination of methods in perspective and differential geometry and continuum mechanics. Topics, include perspective projection transformation, perspective developable conical surface and its applications, perspective projection of motion field on surface, the correspondence problem, composite image space perspective invariants, and motion equations of image intensity. The developed methods provide useful tools for experimentalists to determine morphology and motion field of deformable bodies from images.
C1 NASA Langley Res Ctr, Hampton, VA 23681 USA.
RP Liu, T (reprint author), NASA Langley Res Ctr, Hampton, VA 23681 USA.
EM t.liu@larc.nasa.gov
NR 30
TC 8
Z9 8
U1 0
U2 1
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0001-1452
J9 AIAA J
JI AIAA J.
PD SEP
PY 2004
VL 42
IS 9
BP 1910
EP 1920
DI 10.2514/1.1960
PG 11
WC Engineering, Aerospace
SC Engineering
GA 854TG
UT WOS:000223925600022
ER
PT J
AU Lawson, J
Doran, PT
Kenig, F
Des Marais, DJ
Priscu, JC
AF Lawson, J
Doran, PT
Kenig, F
Des Marais, DJ
Priscu, JC
TI Stable carbon and nitrogen isotopic composition of benthic and pelagic
organic matter in lakes of the McMurdo Dry Valleys, Antarctica
SO AQUATIC GEOCHEMISTRY
LA English
DT Article
DE carbon stable isotope; nitrogen stable isotope; organic matter;
limnology; Antarctica; dry valleys; Taylor Valley
ID ICE-COVERED LAKE; LAST GLACIAL MAXIMUM; TAYLOR VALLEY; ROSS SEA;
LACUSTRINE SEDIMENTS; MARINE-PHYTOPLANKTON; MICROBIAL MATS; GROWTH-RATE;
FRACTIONATION; HOARE
AB The perennially ice-covered lakes in the McMurdo Dry Valleys, Antarctica, are part of the coldest and driest ecosystem on earth. To understand lacustrine carbon and nitrogen cycling in this end-member ecosystem, and to de. ne paleolimnological proxies for ice-covered lakes, we measured the stable carbon and nitrogen isotopic composition of particulate organic matter (POM) and benthic organic matter (BOM) within the lakes of Taylor Valley. The delta(13)C compositions of seasonally ice-free edges of the lakes ( moats) are enriched relative to under-ice organic matter. Thus, the organic carbon isotopic composition of buried sediments may be a proxy for sample position within the lake. In the moats, delta(13)C values are governed by limited CO2 diffusion across benthic cyanobacterial cell membranes. During a high glacial melt ( 2001 - 2002) season, both delta(13)C(POM) and delta(13)C(BOM) in the moats were more depleted than during previous low melt years. We propose that this occurred in response to higher [CO2]((aq)) and/or reduced growth rates resulting from turbidity-induced light limitation. Though moats and under-ice environments are usually poorly connected, during the 2001 - 2002 season, the enrichment of the delta(13)C(POM) values at 6 m depth in the stream-proximal sites relative to deep-profile sites implies enhanced connectivity between these environments. The delta(13)C compositions of BOM and POM profiles in Lake Hoare and Lake Fryxell indicate that these lakes are dominated by benthic productivity. In contrast, in Lake Bonney, the similarity of the delta(13)C values of BOM and POM indicates the pelagic component dominance in the carbon cycle.
C1 Univ Illinois, Dept Earth & Environm Sci, Chicago, IL 60607 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Montana State Univ, Dept Land Resources & Environm Sci, Bozeman, MT 59717 USA.
RP Lawson, J (reprint author), Univ Illinois, Dept Earth & Environm Sci, Chicago, IL 60607 USA.
EM jlawso2@uic.edu
RI Kenig, Fabien/A-4961-2008;
OI Kenig, Fabien/0000-0003-4868-5232
NR 86
TC 29
Z9 30
U1 0
U2 12
PU KLUWER ACADEMIC PUBL
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 1380-6165
J9 AQUAT GEOCHEM
JI Aquat. Geochem.
PD SEP-DEC
PY 2004
VL 10
IS 3-4
BP 269
EP 301
DI 10.1007/s10498-004-2262-2
PG 33
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 868JQ
UT WOS:000224910300005
ER
PT J
AU Venkateswaran, K
Chung, S
Allton, J
Kern, R
AF Venkateswaran, K
Chung, S
Allton, J
Kern, R
TI Evaluation of various cleaning methods to remove Bacillus spores from
spacecraft hardware materials
SO ASTROBIOLOGY
LA English
DT Article
DE spacecraft materials; cleaning; spores; disinfection
ID ASSEMBLY FACILITY; DISINFECTANTS; RESISTANCE
AB A detailed study was made of the biological cleaning effectiveness, defined in terms of the ability to remove bacterial spores, of a number of methods used to clean hardware surfaces. Aluminum (Al 6061) and titanium (Ti 6Al-4V) were chosen for the study as they were deemed the two materials most likely to be used in spacecraft extraterrestrial sampler construction. Metal coupons (1 cm x 2.5 cm) were precleaned and inoculated with 5.8 x 10(3) cultivable Bacilhis subtilis spores, which are commonly found on spacecraft surfaces and in the assembly environments. The inoculated coupons were subsequently cleaned using: (1) 70% isopropyl alcohol wipe; (2) water wipe; (3) multiple-solvent flight-hardware cleaning procedures used at the Jet Propulsion Laboratory (JPL); (4) Johnson Space Center-developed ultrapure water rinse; and (5) a commercial, semi-aqueous, multiple-solvent (SAMS) cleaning process. The biological cleaning effectiveness was measured by agar plate assay, sterility test (growing in liquid media), and epifluorescent microscopy. None of the cleaning protocols tested completely removed viable spores from the surface of the aluminum. In contrast, titanium was capable of being cleaned to sterility by two methods, the JPL standard and the commercial SAMS cleaning process. Further investigation showed that the passivation step employed in the JPL standard method is an effective surface sterilant on both metals but not compatible with aluminum. It is recommended that titanium (Ti 6Al-4V) be considered superior to aluminum (Al 6061) for use in spacecraft sampling hardware, both for its potential to be cleaned to sterilization and for its ability to withstand the most effective cleaning protocols.
C1 CALTECH, Jet Prop Lab, Biotechnol & Planetary Protect Grp, Pasadena, CA 91109 USA.
Johnson Space Ctr, Houston, TX USA.
RP Venkateswaran, K (reprint author), CALTECH, Jet Prop Lab, Biotechnol & Planetary Protect Grp, 4800 Oak Grove Dr,Mail Stop 89, Pasadena, CA 91109 USA.
EM kjvenkat@jpl.nasa.gov
NR 18
TC 28
Z9 29
U1 0
U2 7
PU MARY ANN LIEBERT INC
PI LARCHMONT
PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA
SN 1531-1074
J9 ASTROBIOLOGY
JI Astrobiology
PD FAL
PY 2004
VL 4
IS 3
BP 377
EP 390
DI 10.1089/1531107041939420
PG 14
WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary
SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics;
Geology
GA 854TJ
UT WOS:000223925900005
PM 15383241
ER
PT J
AU Jacobson, RA
Owen, WM
AF Jacobson, RA
Owen, WM
TI The orbits of the inner Neptunian satellites from Voyager, Earth-based,
and Hubble Space Telescope observations
SO ASTRONOMICAL JOURNAL
LA English
DT Article
DE ephemerides; planets and satellites : general; planets and satellites :
individual (Neptune); solar system : general
ID RING ARCS; ICRS
AB We present revised orbital elements for the six small Neptunian satellites discovered by Voyager 2. The elements have been determined from a fit to imaging data acquired by the Voyager 2 spacecraft and astrometric observations made at Earth-based observatories and by the Hubble Space Telescope. An assessment of the accuracy of the elements is provided, as are comparisons with orbits found by previous investigators.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Jacobson, RA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM robert.jacobson@jpl.nasa.gov
NR 22
TC 8
Z9 8
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-6256
J9 ASTRON J
JI Astron. J.
PD SEP
PY 2004
VL 128
IS 3
BP 1412
EP 1417
DI 10.1086/423037
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850SW
UT WOS:000223633800034
ER
PT J
AU Branduardi-Raymont, G
Elsner, RF
Gladstone, GR
Ramsay, G
Rodriguez, P
Soria, R
Waite, JH
AF Branduardi-Raymont, G
Elsner, RF
Gladstone, GR
Ramsay, G
Rodriguez, P
Soria, R
Waite, JH
TI First observation of Jupiter by XMM-Newton
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE planets and satellites : general; planets and satellites : individual :
Jupiter; X-rays : general
ID X-RAY-EMISSION; MAGNETOSPHERE; PRECIPITATION; BURSTS; IONS
AB We present the first X-ray observation of Jupiter by XMM-Newton. Images taken with the EPIC cameras show prominent emission, essentially all confined to the 0.2-2.0 keV band, from the planet's auroral spots; their spectra can be modelled with a combination of unresolved emission lines of highly ionised oxygen (OVII and OVIII), and a pseudo-continuum which may also be due to the superposition of many weak lines. A 2.8sigma enhancement in the RGS spectrum at 21-22 Angstrom (similar to0.57 keV) is consistent with an OVII identification. Our spectral analysis supports the hypothesis that Jupiter's auroral emissions originate from the capture and acceleration of solar wind ions in the planet's magnetosphere, followed by X-ray production by charge exchange. The X-ray flux of the North spot is modulated at Jupiter's rotation period. We do not detect evidence for the similar to45 min X-ray oscillations observed by Chandra more than two years earlier. Emission from the equatorial regions of the planet's disk is also observed. Its spectrum is consistent with that of scattered solar X-rays.
C1 UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England.
NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
SW Res Inst, San Antonio, TX 78228 USA.
XMM Newton SOC, Madrid 28080, Spain.
Univ Michigan, Ann Arbor, MI 48109 USA.
RP UCL, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England.
EM gbr@mssl.ucl.ac.uk
NR 23
TC 35
Z9 35
U1 1
U2 1
PU EDP SCIENCES S A
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 1432-0746
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD SEP
PY 2004
VL 424
IS 1
BP 331
EP 337
DI 10.1051/0004-6361:20041149
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857DD
UT WOS:000224095500030
ER
PT J
AU Standish, EM
AF Standish, EM
TI An approximation to the errors in the planetary ephemerides of the
Astronomical Almanac (vol 417, pg 1165, 2004)
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Correction
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Standish, EM (reprint author), CALTECH, Jet Prop Lab, 301-150, Pasadena, CA 91109 USA.
EM ems@smyles.jpl.nasa.gov
NR 3
TC 0
Z9 0
U1 0
U2 0
PU E D P SCIENCES
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD SEP
PY 2004
VL 424
IS 1
BP 345
EP 345
DI 10.1051/0004-6361:20035663e
PG 1
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 857DD
UT WOS:000224095500032
ER
PT J
AU Benoit, A
Ade, P
Amblard, A
Ansari, R
Aubourg, E
Bargot, S
Bartlett, JG
Bernard, JP
Bhatia, RS
Blanchard, A
Bock, JJ
Boscaleri, A
Bouchet, FR
Bourrachot, A
Camus, P
Couchot, F
de Bernardis, P
Delabrouille, J
Desert, FX
Dore, O
Douspis, M
Dumoulin, L
Dupac, X
Filliatre, P
Fosalba, P
Ganga, K
Gannaway, F
Gautier, B
Giard, M
Giraud-Heraud, Y
Gispert, R
Guglielmi, L
Hamilton, JC
Hanany, S
Henrot-Versille, S
Kaplan, J
Lagache, G
Lamarre, JM
Lange, AE
Macias-Perez, JF
Madet, K
Maffei, B
Magneville, C
Marrone, DR
Masi, S
Mayet, F
Murphy, A
Naraghi, F
Nati, F
Patanchon, G
Perrin, G
Piat, M
Ponthieu, N
Prunet, S
Puget, JL
Renault, C
Rosset, C
Santos, D
Starobinsky, A
Strukov, I
Sudiwala, RV
Teyssier, R
Tristram, M
Tucker, C
Vanel, JC
Vibert, D
Wakui, E
Yvon, D
AF Benoit, A
Ade, P
Amblard, A
Ansari, R
Aubourg, E
Bargot, S
Bartlett, JG
Bernard, JP
Bhatia, RS
Blanchard, A
Bock, JJ
Boscaleri, A
Bouchet, FR
Bourrachot, A
Camus, P
Couchot, F
de Bernardis, P
Delabrouille, J
Desert, FX
Dore, O
Douspis, M
Dumoulin, L
Dupac, X
Filliatre, P
Fosalba, P
Ganga, K
Gannaway, F
Gautier, B
Giard, M
Giraud-Heraud, Y
Gispert, R
Guglielmi, L
Hamilton, JC
Hanany, S
Henrot-Versille, S
Kaplan, J
Lagache, G
Lamarre, JM
Lange, AE
Macias-Perez, JF
Madet, K
Maffei, B
Magneville, C
Marrone, DR
Masi, S
Mayet, F
Murphy, A
Naraghi, F
Nati, F
Patanchon, G
Perrin, G
Piat, M
Ponthieu, N
Prunet, S
Puget, JL
Renault, C
Rosset, C
Santos, D
Starobinsky, A
Strukov, I
Sudiwala, RV
Teyssier, R
Tristram, M
Tucker, C
Vanel, JC
Vibert, D
Wakui, E
Yvon, D
TI First detection of polarization of the submillimetre diffuse galactic
dust emission by Archeops
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE cosmology : cosmic microwave background; cosmology : observations; ISM :
dust, extinction; polarization; submillimeter
ID MICROWAVE BACKGROUND-RADIATION; PROBE WMAP OBSERVATIONS;
HIGH-RESOLUTION; MAPS; TRANSDUCER; STARLIGHT; GRAINS; DASI; COBE
AB We present the first determination of the Galactic polarized emission at 353 GHz by Archeops. The data were taken during the Arctic night of February 7, 2002 after the balloon-borne instrument was launched by CNES from the Swedish Esrange base near Kiruna. In addition to the 143 GHz and 217 GHz frequency bands dedicated to CMB; studies, Archeops had one 545 GHz and six 353 GHz bolometers mounted in three polarization-sensitive pairs that were used for Galactic foreground studies. We present maps of the I, Q, U Stokes parameters over 17% of the sky and with a 13 arcmin resolution at 353 GHz (850 mum). They show a significant Galactic large scale polarized emission coherent on the longitude ranges [100, 120] and [180, 200] deg. with a degree of polarization at the level of 4-5%, in agreement with expectations from starlight polarization measurements. Some regions in the Galactic plane (Gem OB 1, Cassiopeia) show an even stronger degree of polarization in the range 10-20%. These findings provide strong evidence for a powerful grain alignment mechanism throughout the interstellar medium and a coherent magnetic field coplanar to the Galactic plane. This magnetic field pervades even some dense clouds. Extrapolated to high Galactic latitude, these results indicate that interstellar dust polarized emission is the major foreground for PLANCK-HFI CMB polarization measurements.
C1 CNRS, Ctr Rech Tres Basses Temp, F-38042 Grenoble 9, France.
Cardiff Univ, Dept Phys, Cardiff CF24 3YB, S Glam, Wales.
Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA.
Lab Accelerateur Lineaire, F-91898 Orsay, France.
CEA, CE Saclay, DAPNIA, Serv Phys Particules, F-91191 Gif Sur Yvette, France.
Coll France, F-75231 Paris 5, France.
Univ Paris 07, Federat Rech APC, Paris, France.
Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France.
European Space Agcy, ESTEC, Div Astrophys, NL-2201 AZ Noordwijk, Netherlands.
Observ Midi Pyrenees, Astrophys Lab, F-31400 Toulouse, France.
CALTECH, Pasadena, CA 91125 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
CNR, IROE, I-50127 Florence, Italy.
Inst Astrophys, F-75014 Paris, France.
Univ Roma La Sapienza, Dipartimento Fis, Grp Cosmol Sperimentale, I-00185 Rome, Italy.
Observ Grenoble, Astrophys Lab, F-38041 Grenoble 9, France.
Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA.
Nucl & Astrophys Lab, Oxford OX1 3RH, England.
CSNSM, IN2P3, F-91405 Orsay, France.
CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA.
Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France.
Univ Paris 06, LPNHE, F-75252 Paris 05, France.
Univ Paris 07, LPNHE, F-75252 Paris 05, France.
Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA.
Observ Paris, LERMA, F-75014 Paris, France.
Lab Phys Subatom & Cosmol, F-38026 St Martin Dheres, France.
Natl Univ Ireland, Maynooth, Kildare, Ireland.
LD Landau Theoret Phys Inst, Moscow 119334, Russia.
Space Res Inst, Moscow, Russia.
CEA, CE Saclay, DAPNIA, Serv Astrophys, F-91191 Gif Sur Yvette, France.
Lab Leprince Ringuet, F-91128 Palaiseau, France.
RP Benoit, A (reprint author), CNRS, Ctr Rech Tres Basses Temp, BP166, F-38042 Grenoble 9, France.
EM benoit@grenoble.cnrs.fr
RI Bouchet, Francois/B-5202-2014; amblard, alexandre/L-7694-2014; Yvon,
Dominique/D-2280-2015; Fosalba Vela, Pablo/I-5515-2016; Nati,
Federico/I-4469-2016;
OI amblard, alexandre/0000-0002-2212-5395; Nati,
Federico/0000-0002-8307-5088; Marrone, Daniel/0000-0002-2367-1080; Masi,
Silvia/0000-0001-5105-1439; de Bernardis, Paolo/0000-0001-6547-6446;
Bouchet, Francois/0000-0002-8051-2924; Starobinsky,
Alexei/0000-0002-8946-9088
NR 40
TC 95
Z9 96
U1 0
U2 5
PU E D P SCIENCES
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD SEP
PY 2004
VL 424
IS 2
BP 571
EP 582
DI 10.1051/0004-6361:20040042
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 859XD
UT WOS:000224300800024
ER
PT J
AU Cuntz, M
Suess, ST
AF Cuntz, M
Suess, ST
TI Properties of longitudinal flux tube waves - III. Wave propagation in
solar and stellar wind flows
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE magnetohydrodynamics (MHD); shock waves; Sun : solar wind; stars :
winds, outflows
ID SLOW MAGNETOSONIC WAVES; CORONAL HEATING MECHANISMS; POLAR PLUMES;
CHROMOSPHERE MODELS; CONVECTION ZONE; WHITE-LIGHT; ATMOSPHERE; STRENGTH;
STARS
AB We discuss the analytic properties of longitudinal tube waves taking into account ambient wind flows. This is an extension of the studies of Papers I and II, which assumed a mean flow speed of zero and also dealt with a simplified horizontal pressure balance. Applications include the study of longitudinal flux tube waves in stars with significant mass loss and the heating and dynamics of plumes in the solar wind. Slow magnetosonic waves, also called longitudinal waves, have been observed in solar plumes and are likely an important source of heating. We show that the inclusion of ambient wind flows considerably alters the limiting shock strength as well as the energy damping length of the waves.
C1 Univ Texas Arlington, Dept Phys, Arlington, TX 76019 USA.
NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA.
RP Cuntz, M (reprint author), Univ Texas Arlington, Dept Phys, Sci Hall, Arlington, TX 76019 USA.
EM cuntz@uta.edu; steven.t.suess@nasa.gov
NR 41
TC 4
Z9 4
U1 0
U2 0
PU E D P SCIENCES
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD SEP
PY 2004
VL 424
IS 3
BP 1003
EP 1010
DI 10.1051/0004-6361:20040497
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 862HF
UT WOS:000224480900028
ER
PT J
AU Raouafi, NE
Mancuso, S
Solanki, SK
Inhester, B
Mierla, M
Stenborg, G
Delaboudiniere, JP
Benna, C
AF Raouafi, NE
Mancuso, S
Solanki, SK
Inhester, B
Mierla, M
Stenborg, G
Delaboudiniere, JP
Benna, C
TI Shock wave driven by an expanding system of loops
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE plasmas; Sun : coronal mass ejections (CMEs); Sun : flares; Sun :
corona; Sun : UV radiation; shock waves
ID ULTRAVIOLET CORONAGRAPH SPECTROMETER; MASS EJECTIONS; SOHO MISSION; II
BURSTS; JULY 1996; SOLAR; LASCO; HOLES; EUV
AB We report on a Coronal Mass Ejection (CME) observed on June 27, 1999 by the UltraViolet Coronagraph Spectrometer (UVCS) telescope operating on board the SOHO spacecraft. The CME was also observed by the Large Angle Spectroscopic Coronagraph (LASCO). Emission of hot material has been recorded by UVCS propagating in front of an opening system of loops generated by the CME. The evolution of the UVCS structure is highly correlated with the evolution of the opening loop. The data reveal excess broadening of the O VI doublet lines and an enhancement in the intensity of the Si XII lambda520.66 and lambda499.37 lines due to the motion of the expanding hot gas. The hot gas emission seems to be due to a shock wave propagating in front of a very fast gas bubble traveling along the opening loop system.
C1 Max Planck Inst Sonnesyst Forsch, D-37191 Katlenburg Lindau, Germany.
Osserv Astron Torino, INAF, I-10025 Pino Torinese, Italy.
Catholic Univ Amer, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France.
RP Raouafi, NE (reprint author), Observ Paris, LERMA Dept, Meudon, France.
EM raouafi@1inmpi.mpg.de
RI Solanki, Sami/E-2487-2013; Raouafi, Nour/C-2286-2016;
OI Solanki, Sami/0000-0002-3418-8449; Raouafi, Nour/0000-0003-2409-3742;
Benna, Carlo/0000-0003-1688-2434
NR 32
TC 17
Z9 17
U1 0
U2 1
PU EDP SCIENCES S A
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD SEP
PY 2004
VL 424
IS 3
BP 1039
EP 1048
DI 10.1051/0004-6361:20040083
PG 10
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 862HF
UT WOS:000224480900031
ER
PT J
AU Sadat, R
Blanchard, A
Kneib, JP
Mathez, G
Madore, B
Mazzarella, JA
AF Sadat, R
Blanchard, A
Kneib, JP
Mathez, G
Madore, B
Mazzarella, JA
TI Introducing BAX: A database for X-ray clusters and groups of galaxies
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE galaxies : clusters : general; X-rays : galaxies; astronomical databases
: miscellaneous
ID EVOLUTION; SATELLITE
AB We present BAX, Base de Donnees Amas de Galaxies X (http://bax.ast.obs-mip.fr), a multi-wavelength database dedicated to X-ray clusters and groups of galaxies allowing detailed information retrieval. BAX is designed to support astronomical research by providing access to published measurements of the main physical quantities and to the related bibliographic references: basic data stored in the database are cluster/group identifiers, equatorial coordinates, redshift, flux, X-ray luminosity (in the ROSAT band) and temperature, and links to additional linked parameters (in X-rays, such as spatial profile parameters, as well as SZ parameters of the hot gas, lensing measurements, and data at other wavelengths, such as optical and radio). The clusters and groups in BAX can be queried by the basic parameters as well as the linked parameters or combinations of these. We expect BAX to become an important tool for the astronomical community. BAX will optimize various aspects of the scientific analysis of X-ray clusters and groups of galaxies, from proposal planning to data collection, interpretation and publication, from both ground based facilities like MEGACAM (CFHT), VIRMOS (VLT) and space missions like XMM-Newton, Chandra and Planck.
C1 Observ Midi Pyrenees, Astrophys Lab, F-31400 Toulouse, France.
CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA.
CALTECH, Dept Astron, Pasadena, CA 91125 USA.
RP Sadat, R (reprint author), Observ Midi Pyrenees, Astrophys Lab, 14 Ave E Belin, F-31400 Toulouse, France.
EM rsadat@ast.obs-mip.fr
RI Kneib, Jean-Paul/A-7919-2015;
OI Kneib, Jean-Paul/0000-0002-4616-4989; Mazzarella,
Joseph/0000-0002-8204-8619
NR 25
TC 24
Z9 24
U1 0
U2 1
PU E D P SCIENCES
PI LES ULIS CEDEX A
PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A,
FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD SEP
PY 2004
VL 424
IS 3
BP 1097
EP 1100
DI 10.1051/0004-6361:20034029
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 862HF
UT WOS:000224480900037
ER
PT J
AU Blanc, G
Afonso, C
Alard, C
Albert, JN
Aldering, G
Amadon, A
Andersen, J
Ansari, R
Aubourg, E
Balland, C
Bareyre, P
Beaulieu, JP
Charlot, X
Conley, A
Coutures, C
Dahlen, T
Derue, F
Fan, X
Ferlet, R
Folatelli, G
Fouque, P
Garavini, G
Glicenstein, JF
Goldman, B
Goobar, A
Gould, A
Graff, D
Gros, M
Haissinski, J
Hamadache, C
Hardin, D
Hook, IM
de Kat, J
Kent, S
Kim, A
Lasserre, T
Le Guillou, L
Lesquoy, E
Loup, C
Magneville, C
Marquette, JB
Maurice, E
Maury, A
Milsztajn, A
Moniez, M
Mouchet, M
Newberg, H
Nobili, S
Palanque-Delabrouille, N
Perdereau, O
Prevot, L
Rahal, YR
Regnault, N
Rich, J
Ruiz-Lapuente, P
Spiro, M
Tisserand, P
Vidal-Madjar, A
Vigroux, L
Walton, NA
Zylberajch, S
AF Blanc, G
Afonso, C
Alard, C
Albert, JN
Aldering, G
Amadon, A
Andersen, J
Ansari, R
Aubourg, E
Balland, C
Bareyre, P
Beaulieu, JP
Charlot, X
Conley, A
Coutures, C
Dahlen, T
Derue, F
Fan, X
Ferlet, R
Folatelli, G
Fouque, P
Garavini, G
Glicenstein, JF
Goldman, B
Goobar, A
Gould, A
Graff, D
Gros, M
Haissinski, J
Hamadache, C
Hardin, D
Hook, IM
de Kat, J
Kent, S
Kim, A
Lasserre, T
Le Guillou, L
Lesquoy, E
Loup, C
Magneville, C
Marquette, JB
Maurice, E
Maury, A
Milsztajn, A
Moniez, M
Mouchet, M
Newberg, H
Nobili, S
Palanque-Delabrouille, N
Perdereau, O
Prevot, L
Rahal, YR
Regnault, N
Rich, J
Ruiz-Lapuente, P
Spiro, M
Tisserand, P
Vidal-Madjar, A
Vigroux, L
Walton, NA
Zylberajch, S
TI Type Ia supernova rate at a redshift of similar to 0.1
SO ASTRONOMY & ASTROPHYSICS
LA English
DT Article
DE stars : supernovae : general; galaxies : evolution; cosmology :
miscellaneous; methods : observational
ID BVRI LIGHT CURVES; LUMINOSITY FUNCTION; MAGELLANIC-CLOUD;
STAR-FORMATION; GALAXY; EVOLUTION; DENSITY; COUNTS; MAPS
AB We present the type la rate measurement based on two EROS supernova search campaigns (in 1999 and 2000). Sixteen supernovae identified as type la were discovered. The measurement of the detection efficiency, using a Monte Carlo simulation, provides the type la supernova explosion rate at a redshift similar to0.13. The result is 0.125(-0.034-0.028)(+0.044+0.028) h(70)(2) SNu where 1 SNu = 1 SN / 10(10) L-.(B) / century. This value is compatible with the previous EROS measurement (Hardin et al. 2000), done with a much smaller sample, at a similar redshift. Comparison with other values at different redshifts suggests an evolution of the type la supernova rate.
C1 CEA Saclay, DSM, DAPNIA, F-91191 Gif Sur Yvette, France.
Univ Paris 11, CNRS, IN2P3, Lab Accelerateur Lineaire, F-91405 Orsay, France.
Observ Marseille, F-13248 Marseille, France.
Coll France, CNRS, IN2P3, F-75231 Paris, France.
CNRS, INSU, Inst Astrophys Paris, F-75014 Paris, France.
Univ Copenhagen, Astron Observ, DK-2100 Copenhagen, Denmark.
Ohio State Univ, Dept Astron, Columbus, OH 43210 USA.
Ohio State Univ, Dept Phys, Columbus, OH 43210 USA.
New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA.
European So Observ, Santiago 19, Chile.
Observ Midi Pyrenees, F-31400 Toulouse, France.
Univ Stockholm, Dept Phys, AlbaNova Univ Ctr, S-10691 Stockholm, Sweden.
Osserv Astron Padova, INAF, I-35122 Padua, Italy.
Univ Paris 06, CNRS, IN2P3, Lab Phys Nucl & Hautes Energies, F-75252 Paris 05, France.
Univ Paris 07, CNRS, IN2P3, Lab Phys Nucl & Hautes Energies, F-75252 Paris 05, France.
Ecole Polytech, LLR, Lab Leprince Ringuet, F-91128 Palaiseau, France.
Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA.
Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
Rensselaer Polytech Inst, Troy, NY 12180 USA.
Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA.
Space Telescope Sci Inst, Baltimore, MD 21218 USA.
Observ Paris, LUTH, F-92195 Meudon, France.
Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France.
Univ Paris 07, F-75005 Paris, France.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Observ Paris, GEPI, F-75014 Paris, France.
Univ Oxford, Dept Phys, Nucl & Astrophys Lab, Oxford OX1 3RH, England.
Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England.
Univ Barcelona, Dept Astron, Barcelona, Spain.
RP Blanc, G (reprint author), CEA Saclay, DSM, DAPNIA, F-91191 Gif Sur Yvette, France.
EM blanc@pd.astro.it
RI Folatelli, Gaston/A-4484-2011; Le Guillou, Laurent/B-7712-2009
NR 46
TC 56
Z9 56
U1 0
U2 0
PU E D P SCIENCES
PI LES ULIS CEDEXA
PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS
CEDEXA, FRANCE
SN 0004-6361
J9 ASTRON ASTROPHYS
JI Astron. Astrophys.
PD SEP
PY 2004
VL 423
IS 3
BP 881
EP 894
DI 10.1051/0004-6361:20035948
PG 14
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 853SY
UT WOS:000223850400013
ER
PT J
AU Eriksen, HK
Novikov, DI
Lilje, PB
Banday, AJ
Gorski, KM
AF Eriksen, HK
Novikov, DI
Lilje, PB
Banday, AJ
Gorski, KM
TI Testing for non-gaussianity in the Wilkinson Microwave Anisotropy Probe
data: Minkowski functionals and the length of the skeleton
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE cosmic microwave background; cosmology : observations; methods :
statistical
ID WMAP OBSERVATIONS; MAPS; TOPOLOGY; ASYMMETRIES; CURVATURE
AB The three Minkowski functionals and the recently defined length of the skeleton are estimated for the co-added first-year Wilkinson Microwave Anisotropy Probe (WMAP) data and compared with 5000 Monte Carlo simulations, based on Gaussian fluctuations with the a priori best-fit running-index power spectrum and WMAP-like beam and noise properties. Several power spectrum-dependent quantities, such as the number of stationary points, the total length of the skeleton, and a spectral parameter, gamma, are also estimated. While the area and length Minkowski functionals and the length of the skeleton show no evidence for departures from the Gaussian hypothesis, the northern hemisphere genus has a chi(2) that is large at the 95% level for all scales. For the particular smoothing scale of 3.degrees40 FWHM it is larger than that found in 99.5% of the simulations. In addition, the WMAP genus for negative thresholds in the northern hemisphere has an amplitude that is larger than in the simulations with a significance of more than 3 sigma. On the smallest angular scales considered, the number of extrema in the WMAP data is high at the 3 sigma level. However, this can probably be attributed to the effect of point sources. Finally, the spectral parameter gamma is high at the 99% level in the northern Galactic hemisphere, while perfectly acceptable in the southern hemisphere. The results provide strong evidence for the presence of both non-Gaussian behavior and an unexpected power asymmetry between the northern and southern hemispheres in the WMAP data.
C1 Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway.
Max Planck Inst Astrophys, D-85741 Garching, Germany.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Warsaw Observ, PL-00478 Warsaw, Poland.
Univ Oslo, Ctr Math Applicat, N-0316 Oslo, Norway.
CALTECH, Pasadena, CA 91125 USA.
RP Univ Oslo, Inst Theoret Astrophys, POB 1029, N-0315 Oslo, Norway.
EM h.k.k.eriksen@astro.uio.no; d.novikov@imperial.ac.uk;
per.lilje@astro.uio.no; banday@mpa-garching.mpg.de;
krzysztof.m.gorski@jpl.nasa.gov
RI Lilje, Per/A-2699-2012; Novikov, Dmitry/P-1807-2015;
OI Lilje, Per/0000-0003-4324-7794
NR 31
TC 132
Z9 139
U1 0
U2 11
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 1
PY 2004
VL 612
IS 1
BP 64
EP 80
DI 10.1086/422570
PN 1
PG 17
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TC
UT WOS:000223634400006
ER
PT J
AU Fixsen, DJ
Kogut, A
Levin, S
Limon, M
Lubin, P
Mirel, P
Seiffert, M
Wollack, E
AF Fixsen, DJ
Kogut, A
Levin, S
Limon, M
Lubin, P
Mirel, P
Seiffert, M
Wollack, E
TI The temperature of the cosmic microwave background at 10 GHz
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE cosmic microwave background; cosmology : observations
ID ABSOLUTE MEASUREMENT; RADIATION TEMPERATURE; SPECTRUM; EMISSION;
UNIVERSE; DISTORTIONS; CENTIMETERS; SIGNATURES; FIRAS; COBE
AB We report the results of an effort to measure the low-frequency portion of the spectrum of the cosmic microwave background (CMB) radiation, using a balloon-borne instrument called the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE). These measurements are to search for deviations from a thermal spectrum that are expected to exist in the CMB as a result of various processes in the early universe. The radiometric temperature was measured at 10 and 30 GHz using a cryogenic open-aperture instrument with no emissive windows. An external blackbody calibrator provides an in situ reference. Systematic errors were greatly reduced by using differential radiometers and cooling all critical components to physical temperatures approximating the antenna temperature of the sky. A linear model is used to compare the radiometer output to a set of thermometers on the instrument. The unmodeled residuals are less than 50 mK peak to peak with a weighted rms of 6 mK. Small corrections are made for the residual emission from the flight train, atmosphere, and foreground Galactic emission. The measured radiometric temperature of the CMB is 2.721 +/- 0.010 K at 10 GHz and 2.694 +/- 0.032 K at 30 GHz.
C1 NASA, Sci Syst & Applicat Inc, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA.
RP Fixsen, DJ (reprint author), NASA, Sci Syst & Applicat Inc, Goddard Space Flight Ctr, Code 685, Greenbelt, MD 20771 USA.
EM fixsen@stars.gsfc.nasa.gov
RI Kogut, Alan/D-6293-2012; Wollack, Edward/D-4467-2012
OI Wollack, Edward/0000-0002-7567-4451
NR 27
TC 24
Z9 24
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 1
PY 2004
VL 612
IS 1
BP 86
EP 95
DI 10.1086/421993
PN 1
PG 10
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TC
UT WOS:000223634400008
ER
PT J
AU Crenshaw, DM
Kraemer, SB
Gabel, JR
Schmitt, HR
Filippenko, AV
Ho, LC
Shields, JC
Turner, TJ
AF Crenshaw, DM
Kraemer, SB
Gabel, JR
Schmitt, HR
Filippenko, AV
Ho, LC
Shields, JC
Turner, TJ
TI High-resolution ultraviolet spectra of the dwarf Seyfert 1 galaxy NGC
4395: Evidence for intrinsic absorption
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE galaxies : individual (NGC 4395); galaxies : Seyfert; ultraviolet :
galaxies
ID ACTIVE GALACTIC NUCLEI; X-RAY-ABSORPTION; NGC 4395; PHYSICAL CONDITIONS;
SPIRAL GALAXIES; SPACE-TELESCOPE; STAR-FORMATION; BLACK-HOLE; LINES; GAS
AB We present ultraviolet spectra of the dwarf Seyfert 1 nucleus of NGC 4395, obtained with the Far Ultraviolet Spectroscopic Explorer ( FUSE) and the Hubble Space Telescope Space Telescope Imaging Spectrograph at velocity resolutions of 7 - 15 km s(-1). We confirm our earlier claim of C IV absorption in low-resolution UV spectra and detect a number of other absorption lines with lower ionization potentials. In addition to the Galactic lines, we identify two kinematic components of absorption that are likely to be intrinsic to NGC 4395. We consider possible origins of the absorption, including the interstellar medium ( ISM) of NGC 4395, the narrow-line region, the outflowing UV absorbers, and the X-ray "warm absorbers.'' Component 1, at a radial velocity of - 770 km s(-1) with respect to the nucleus, is only identified in the C IV lambda1548.2 line. It most likely represents an outflowing UV absorber, similar to those seen in a majority of Seyfert 1 galaxies, although additional observations are needed to confirm the reality of this feature. Component 2, at - 114 km s(-1), most likely arises in the ISM of NGC 4395; its ionic column densities cannot be matched by photoionization models with a power-law continuum. Our models of the highly ionized X-ray absorbers claimed for this active galactic nucleus indicate that they would have undetectable C IV absorption, but large O vi and H I columns should be present. We attribute our lack of detection of the O vi and Lybeta absorption from the X-ray absorbers to a combination of noise and dilution of the nuclear spectrum by hot stars in the large FUSE aperture.
C1 Georgia State Univ, Dept Phys & Astron, Astron Off, Atlanta, GA 30303 USA.
Catholic Univ Amer, Greenbelt, MD 20771 USA.
NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Colorado, Ctr Astrophys & Space Astron, UCB 389, Boulder, CO 80309 USA.
Natl Radio Astron Observ, Charlottesville, VA 22903 USA.
Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA.
Observ Carnegie Inst Washington, Pasadena, CA 91101 USA.
Ohio Univ, Dept Phys & Astron, Athens, OH 45701 USA.
Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Baltimore, MD 21250 USA.
RP Crenshaw, DM (reprint author), Georgia State Univ, Dept Phys & Astron, Astron Off, 1 Pk Pl S SE,Suite 700, Atlanta, GA 30303 USA.
EM crenshaw@chara.gsu.edu; stiskraemer@yancey.gsfc.nasa.gov;
jack.gabel@colorado.edu; hschmitt@nrao.edu; alex@astro.berkeley.edu;
lho@ociw.edu; shields@helios.phy.ohiou.edu;
turner@lucretia.gsfc.nasa.gov
NR 37
TC 15
Z9 15
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 1
PY 2004
VL 612
IS 1
BP 152
EP 158
DI 10.1086/422468
PN 1
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TC
UT WOS:000223634400013
ER
PT J
AU Menanteau, F
Ford, HC
Illingworth, GD
Sirianni, M
Blakeslee, JP
Meurer, GR
Martel, AR
Benitez, N
Postman, M
Franx, M
Ardila, DR
Bartko, F
Bouwens, RJ
Broadhurst, TJ
Brown, RA
Burrows, CJ
Cheng, ES
Clampin, M
Cross, NJG
Feldman, PD
Golimowski, DA
Gronwall, C
Hartig, GF
Infante, L
Kimble, RA
Krist, JE
Lesser, MP
Miley, GK
Rosati, P
Sparks, WB
Tran, HD
Tsvetanov, ZI
White, RL
Zheng, W
AF Menanteau, F
Ford, HC
Illingworth, GD
Sirianni, M
Blakeslee, JP
Meurer, GR
Martel, AR
Benitez, N
Postman, M
Franx, M
Ardila, DR
Bartko, F
Bouwens, RJ
Broadhurst, TJ
Brown, RA
Burrows, CJ
Cheng, ES
Clampin, M
Cross, NJG
Feldman, PD
Golimowski, DA
Gronwall, C
Hartig, GF
Infante, L
Kimble, RA
Krist, JE
Lesser, MP
Miley, GK
Rosati, P
Sparks, WB
Tran, HD
Tsvetanov, ZI
White, RL
Zheng, W
TI Internal color properties of resolved spheroids in the deep Hubble Space
Telescope advanced camera for surveys field of UGC 10214
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE galaxies : elliptical and lenticular, cD; galaxies : evolution; galaxies
: fundamental parameters
ID EARLY-TYPE GALAXIES; ELLIPTIC GALAXIES; MAGNITUDE RELATION;
INTERMEDIATE-REDSHIFT; HIERARCHICAL-MODELS; SURFACE-BRIGHTNESS;
EVOLUTION; GRADIENTS; SEQUENCE; CLUSTERS
AB We study the internal color properties of a morphologically selected sample of spheroidal galaxies taken from the Hubble Space Telescope (HST) Advanced Camera for Surveys ( ACS) Early Release Observation program of UGC 10214 ("the Tadpole''). By taking advantage of the unprecedented high resolution of the ACS in this very deep data set, we are able to characterize spheroids at subarcsecond scales. Using the V-606 and I-814 bands, we construct V - I color maps and extract color gradients for a sample of spheroids at I-814 < 24 mag. We assess the ability of the ACS to make resolved color studies of galaxies by comparing its results with the multicolor data from the Hubble Deep Fields (HDFs). Here we report that with ACS WFC data using less than &SIM; 1/10 the exposure of the WFPC2 HDFs, it is possible to confidently carry out resolved studies of faint galaxies at similar magnitude limits. We also investigate the existence of a population of morphologically classified spheroids that show extreme variation in their internal color properties, similar to the ones reported in the HDFs. These are displayed as blue cores and inverse color gradients with respect to those accounted for from metallicity variations. Following the same analysis, we find a similar fraction of early-type systems ( &SIM; 30% - 40%) that show nonhomologous internal colors, suggestive of recent star formation activity. We present two statistics for quantifying the internal color variation in galaxies and tracing blue cores, from which we estimate the ratio of nonhomogeneous to homogeneous internal colors as a function of redshift up to z&LSIM;1.2. We find that it can be described as about constant as a function of redshift, with a small increase with redshift for the fraction of spheroids that present strong color dispersions. The implications of a constant fraction at all redshifts suggests the existence of a relatively permanent population of evolving spheroids up to z&LSIM;1. We discuss the implications of this in the context of spheroidal formation.
C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA.
Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA.
Space Telescope Sci Inst, Baltimore, MD 21218 USA.
Leiden Observ, NL-2300 RA Leiden, Netherlands.
Bartko Sci & Technol, Mead, CO 80542 USA.
Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel.
NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA.
Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA.
Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile.
Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
European So Observ, D-85748 Garching, Germany.
RP Menanteau, F (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA.
RI White, Richard/A-8143-2012; Clampin, mark/D-2738-2012; Kimble,
Randy/D-5317-2012
OI Benitez, Narciso/0000-0002-0403-7455;
NR 43
TC 39
Z9 39
U1 0
U2 0
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 1
PY 2004
VL 612
IS 1
BP 202
EP 214
DI 10.1086/422568
PN 1
PG 13
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TC
UT WOS:000223634400017
ER
PT J
AU Proffitt, CR
Sahu, K
Livio, M
Krist, J
Calzetti, D
Gilliland, R
Grady, C
Lindler, D
Woodgate, B
Heap, S
Clampin, M
Gull, TR
Lisse, CM
AF Proffitt, CR
Sahu, K
Livio, M
Krist, J
Calzetti, D
Gilliland, R
Grady, C
Lindler, D
Woodgate, B
Heap, S
Clampin, M
Gull, TR
Lisse, CM
TI Limits on the optical brightness of the epsilon Eridani dust ring
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE circumstellar matter; stars : individual (epsilon Eridani)
ID MAIN-SEQUENCE STARS; KUIPER-BELT DUST; VEGA-TYPE STARS;
INFRARED-EMISSION; SOLAR-SYSTEM; NEARBY STARS; TINY-TIM; DISK; PLANETS;
SUBMILLIMETER
AB The STIS CCD camera on the Hubble Space Telescope (HST) was used to take deep optical images near the K2 V main- sequence star epsilon Eridani in an attempt to find an optical counterpart of the dust ring previously imaged by submillimeter observations. Upper limits for the optical brightness of the dust ring are determined and discussed in the context of the scattered starlight expected from plausible dust models. We find that even if the dust is smoothly distributed in symmetrical rings, the optical surface brightness of the dust, as measured with the HST STIS CCD clear aperture at 55 AU from the star, cannot be brighter than about 25 STMAG arcsec(-2). This upper limit excludes some solid-grain models for the dust ring that can fit the IR and submillimeter data. Magnitudes and positions for approximate to59 discrete objects between 12."5 and 58" from epsilon Eri are reported. Most if not all of these objects are likely to be background stars and galaxies.
C1 Comp Sci Corp, Sci Programs, Baltimore, MD 21218 USA.
Space Telescope Sci Inst, Baltimore, MD 21218 USA.
NASA, Goddard Space Flight Ctr, NOAO STIS, Greenbelt, MD 20771 USA.
NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA.
Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
Sigma Res & Engn, Lanham, MD 20706 USA.
Catholic Univ Amer, Inst Astrophys & Computat Sci, Washington, DC 20064 USA.
Eureka Sci, Oakland, CA 94602 USA.
RP Proffitt, CR (reprint author), Comp Sci Corp, Sci Programs, 3700 San Martin Dr, Baltimore, MD 21218 USA.
EM proffitt@stsci.edu
RI Gull, Theodore/D-2753-2012; Clampin, mark/D-2738-2012; Lisse,
Carey/B-7772-2016
OI Gull, Theodore/0000-0002-6851-5380; Lisse, Carey/0000-0002-9548-1526
NR 43
TC 9
Z9 9
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 1
PY 2004
VL 612
IS 1
BP 481
EP 495
DI 10.1086/422549
PN 1
PG 15
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TC
UT WOS:000223634400041
ER
PT J
AU Joseph, T
Lazio, W
Farrell, WM
Dietrick, J
Greenlees, E
Hogan, E
Jones, C
Hennig, LA
AF Joseph, T
Lazio, W
Farrell, WM
Dietrick, J
Greenlees, E
Hogan, E
Jones, C
Hennig, LA
TI The radiometric Bode's law and extrasolar planets
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE magnetic fields; radio continuum : stars; solar wind
ID TERRESTRIAL KILOMETRIC RADIATION; SOLAR-WIND CONTROL; RADIO-EMISSION;
UPSILON ANDROMEDAE; COMPANIONS; NEPTUNE; PREDICTIONS; HD-192263; MASSES;
DISK
AB We predict the radio flux densities of the extrasolar planets in the current census, making use of an empirical relation-the radiometric Bode's law-determined from the five "magnetic'' planets in the solar system (the Earth and the four gas giants). Radio emission from these planets results from solar wind-powered electron currents depositing energy in the magnetic polar regions. We find that most of the known extrasolar planets should emit in the frequency range 10-1000 MHz and, under favorable circumstances, have typical flux densities as large as 1 mJy. We also describe an initial, systematic effort to search for radio emission in low radio frequency images acquired with the Very Large Array (VLA). The limits set by the VLA images (approximate to300 mJy) are consistent with, but do not provide strong constraints on, the predictions of the model. Future radio telescopes, such as the Low Frequency Array and the Square Kilometer Array, should be able to detect the known extrasolar planets or place austere limits on their radio emission. Planets with masses much lower than those in the current census will probably radiate below 10 MHz and will require a space-based array.
C1 USN, Res Lab, Washington, DC 20375 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Thomas Jefferson High Sch Sci & Technol, Alexandria, VA 22312 USA.
RP Joseph, T (reprint author), USN, Res Lab, Code 7213, Washington, DC 20375 USA.
EM joseph.lazio@nrl.navy.mil; william.m.farrell@gsfc.nasa.gov;
hennig@lan.tjhsst.edu
RI Farrell, William/I-4865-2013
NR 43
TC 0
Z9 0
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 1
PY 2004
VL 612
IS 1
BP 511
EP 518
PN 1
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TC
UT WOS:000223634400043
ER
PT J
AU Sui, LH
Holman, GD
Dennis, BR
AF Sui, LH
Holman, GD
Dennis, BR
TI Evidence for magnetic reconnection in three homologous solar flares
observed by RHESSI
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE Sun : flares; Sun : magnetic fields; Sun : X-rays, gamma rays
ID CORONAL MASS EJECTIONS; X-RAY SOURCE; CURRENT SHEET; KINK INSTABILITY;
MODEL; PLASMA; LOOPS; PROMINENCES; MOTIONS; EVENTS
AB We present RHESSI observations of three homologous flares that occurred between 2002 April 14 and 16. We find that the RHESSI images of all three flares at energies between 6 and 25 keV had some common features: (1) A separate coronal source up to similar to30" above the flare loop appeared in the early impulsive phase and stayed stationary for several minutes. (2) Before the flare loop moved upward, as previously reported by others, the flare loop-top centroid moved downward for 2-4 minutes during the early impulsive phase of the flare, falling by 13%-30% of its initial height with a speed between 8 and 23 km s(-1). We conclude that these features are associated with the formation and development of a current sheet between the loop top and the coronal source. In the 2002 April 14-15 flare, we find that the hard X-ray flux (>25 keV) is correlated with the rate at which the flare loop moves upward, indicating that the faster the loop grows, the faster the reconnection rate and therefore the greater the flux of accelerated electrons.
C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA.
Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA.
RP NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 682, Greenbelt, MD 20771 USA.
EM lhsui@stars.gsfc.nasa.gov
RI Holman, Gordon/C-9548-2012; Dennis, Brian/C-9511-2012
NR 50
TC 152
Z9 159
U1 0
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-637X
EI 1538-4357
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 1
PY 2004
VL 612
IS 1
BP 546
EP 556
DI 10.1086/422515
PN 1
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TC
UT WOS:000223634400046
ER
PT J
AU Feng, H
Zhang, SN
Li, TP
AF Feng, H
Zhang, SN
Li, TP
TI Shot cutoff timescales in different spectral states of Cygnus X-1
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE accretion, accretion disks; black hole physics; stars : individual
(Cygnus X-1); X-rays : binaries
ID X-RAY BINARIES; ADVECTION-DOMINATED ACCRETION; BLACK-HOLE; IRON LINE;
EMISSION-LINE; XMM-NEWTON; TIME LAGS; VARIABILITY; COMPTONIZATION;
MCG-6-30-15
AB We investigate the shot cutoff timescale evolutions during different spectral states in the black hole binary Cygnus X-1 with the recently proposed w spectral analysis technique. For low-energy shots, their cutoff timescale decreases from the low state to the intermediate state and to the high state monotonically. However, in the high-energy range, where shots are believed to be reprocessed in the hot corona, timescales are almost the same for different spectral states. A linear correlation is found between the energy spectrum photon index and the shot cutoff timescale at low energies. Both narrow and broad iron Kalpha lines are distinguished from timing analysis, providing dynamical evidence that broad and narrow iron lines originate, respectively, at small and large radii of the accretion disk. Possible mechanisms for state transitions and accretion flow geometry in accreting stellar mass black holes are discussed.
C1 Tsing Hua Univ, Dept Engn Phys, Beijing 100084, Peoples R China.
Tsing Hua Univ, Ctr Astrophys, Beijing 100084, Peoples R China.
Tsing Hua Univ, Dept Phys, Beijing 100084, Peoples R China.
Univ Alabama, Dept Phys, Huntsville, AL 35899 USA.
Chinese Acad Sci, Inst High Energy Phys, Lab Particle Astrophys, Beijing 100039, Peoples R China.
NASA, Space Sci Lab, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
RP Feng, H (reprint author), Tsing Hua Univ, Dept Engn Phys, Beijing 100084, Peoples R China.
EM fenghua01@mail.stsinghua.edu.cn
NR 46
TC 2
Z9 3
U1 2
U2 6
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 1
PY 2004
VL 612
IS 1
BP L45
EP L48
DI 10.1086/424567
PN 2
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TE
UT WOS:000223634600012
ER
PT J
AU Wooden, DH
Woodward, CE
Harker, DE
AF Wooden, DH
Woodward, CE
Harker, DE
TI Discovery of crystalline silicates in comet C/2001 Q4 (NEAT)
SO ASTROPHYSICAL JOURNAL
LA English
DT Article
DE comets : general; comets : individual (NEAT ( C/2001 Q4)); infrared :
solar system
ID COMET HALE-BOPP; SOLAR NEBULA; SURFACE-COMPOSITION; INTERSTELLAR-MEDIUM;
ION IRRADIATION; ACCRETION DISKS; KUIPER-BELT; C/1995 O1; DUST;
EVOLUTION
AB We present the 10 mum silicate feature of the dynamically new Oort Cloud comet C/2001 Q4 (NEAT) 5 days prior to perihelion (r(h)=0.97 AU, Delta=0.35 AU, 2004 May 11.25 and 11.30 UT) observed with the NASA Ames HIFOGS spectrophotometer. The silicate feature of comet Q4 contains strong crystalline peaks at 10.0 and 11.2 mum, along with weaker peaks at 9.3, 10.5, and 11.8 mum, which are characteristic of crystalline olivine and crystalline orthopyroxene. The relative heights of the resonant peaks as well as the shape of the silicate feature in comet Q4 is the same as in comet C/1995 O1 (Hale-Bopp) preperihelion (r(h)=1.21 AU). Thermal emission modeling shows Q4 and Hale-Bopp have similar relative abundances of the silicate minerals and high silicate crystalline-to-amorphous ratios. The silicate-to-amorphous carbon ratio derived for comet Q4, however, is lower than in Hale-Bopp and varies by a factor of similar to2 in 2 hr, potentially sampling material from different jets in the coma. Owing to the similarity in the silicate mineralogy between Q4 and Hale-Bopp, either these two icy planetesimals formed in the same regime or crystalline silicates were widely distributed within the comet-forming zone.
C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA.
Univ Minnesota, Dept Astron, Minneapolis, MN 55455 USA.
Univ Calif San Diego, Ctr Astron & Space Sci, La Jolla, CA 92093 USA.
RP Wooden, DH (reprint author), NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA.
EM wooden@delphinus.arc.nasa; chelsea@astro.umn.edu; harker@talos.ucsd.edu
OI Harker, David/0000-0001-6397-9082
NR 44
TC 52
Z9 52
U1 0
U2 4
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-637X
J9 ASTROPHYS J
JI Astrophys. J.
PD SEP 1
PY 2004
VL 612
IS 1
BP L77
EP L80
DI 10.1086/424593
PN 2
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TE
UT WOS:000223634600020
ER
PT J
AU Werner, MW
Roellig, TL
Low, FJ
Rieke, GH
Rieke, M
Hoffmann, WF
Young, E
Houck, JR
Brandl, B
Fazio, GG
Hora, JL
Gehrz, RD
Helou, G
Soifer, BT
Stauffer, J
Keene, J
Eisenhardt, P
Gallagher, D
Gautier, TN
Irace, W
Lawrence, CR
Simmons, L
Van Cleve, JE
Jura, M
Wright, EL
Cruikshank, DP
AF Werner, MW
Roellig, TL
Low, FJ
Rieke, GH
Rieke, M
Hoffmann, WF
Young, E
Houck, JR
Brandl, B
Fazio, GG
Hora, JL
Gehrz, RD
Helou, G
Soifer, BT
Stauffer, J
Keene, J
Eisenhardt, P
Gallagher, D
Gautier, TN
Irace, W
Lawrence, CR
Simmons, L
Van Cleve, JE
Jura, M
Wright, EL
Cruikshank, DP
TI The Spitzer Space Telescope mission
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE space vehicles : instruments; telescopes
AB The Spitzer Space Telescope, NASA's Great Observatory for infrared astronomy, was launched 2003 August 25 and is returning excellent scientific data from its Earth-trailing solar orbit. Spitzer combines the intrinsic sensitivity achievable with a cryogenic telescope in space with the great imaging and spectroscopic power of modern detector arrays to provide the user community with huge gains in capability for exploration of the cosmos in the infrared. The observatory systems are largely performing as expected, and the projected cryogenic lifetime is in excess of 5 years. This paper summarizes the on-orbit scientific, technical, and operational performance of Spitzer. Subsequent papers in this special issue describe the Spitzer instruments in detail and highlight many of the exciting scientific results obtained during the first 6 months of the Spitzer mission.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
Leiden Univ, NL-2300 RA Leiden, Netherlands.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Univ Minnesota, Sch Phys & Astron, Dept Astron, Minneapolis, MN 55455 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Ball Aerosp & Technol, Boulder, CO 80301 USA.
Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
RP Werner, MW (reprint author), CALTECH, Jet Prop Lab, MS 264-767,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM mwerner@sirtfweb.jpl.nasa.gov
OI Hora, Joseph/0000-0002-5599-4650
NR 9
TC 1777
Z9 1782
U1 3
U2 39
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 1
EP 9
DI 10.1086/422992
PG 9
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300001
ER
PT J
AU Fazio, GG
Hora, JL
Allen, LE
Ashby, MLN
Barmby, P
Deutsch, LK
Huang, JS
Kleiner, S
Marengo, M
Megeath, ST
Melnick, GJ
Pahre, MA
Patten, BM
Polizotti, J
Smith, HA
Taylor, RS
Wang, Z
Willner, SP
Hoffmann, WF
Pipher, JL
Forrest, WJ
McMurty, CW
McCreight, CR
McKelvey, ME
McMurray, RE
Koch, DG
Moseley, SH
Arendt, RG
Mentzell, JE
Marx, CT
Losch, P
Mayman, P
Eichhorn, W
Krebs, D
Jhabvala, M
Gezari, DY
Fixsen, DJ
Flores, J
Shakoorzadeh, K
Jungo, R
Hakun, C
Workman, L
Karpati, G
Kichak, R
Whitley, R
Mann, S
Tollestrup, EV
Eisenhardt, P
Stern, D
Gorjian, V
Bhattacharya, B
Carey, S
Nelson, BO
Glaccum, WJ
Lacy, M
Lowrance, PJ
Laine, S
Reach, WT
Stauffer, JA
Surace, JA
Wilson, G
Wright, EL
Hoffman, A
Domingo, G
Cohen, M
AF Fazio, GG
Hora, JL
Allen, LE
Ashby, MLN
Barmby, P
Deutsch, LK
Huang, JS
Kleiner, S
Marengo, M
Megeath, ST
Melnick, GJ
Pahre, MA
Patten, BM
Polizotti, J
Smith, HA
Taylor, RS
Wang, Z
Willner, SP
Hoffmann, WF
Pipher, JL
Forrest, WJ
McMurty, CW
McCreight, CR
McKelvey, ME
McMurray, RE
Koch, DG
Moseley, SH
Arendt, RG
Mentzell, JE
Marx, CT
Losch, P
Mayman, P
Eichhorn, W
Krebs, D
Jhabvala, M
Gezari, DY
Fixsen, DJ
Flores, J
Shakoorzadeh, K
Jungo, R
Hakun, C
Workman, L
Karpati, G
Kichak, R
Whitley, R
Mann, S
Tollestrup, EV
Eisenhardt, P
Stern, D
Gorjian, V
Bhattacharya, B
Carey, S
Nelson, BO
Glaccum, WJ
Lacy, M
Lowrance, PJ
Laine, S
Reach, WT
Stauffer, JA
Surace, JA
Wilson, G
Wright, EL
Hoffman, A
Domingo, G
Cohen, M
TI The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE infrared : general; instrumentation : detectors; space vehicles :
instruments
ID FOCAL-PLANE ARRAYS; SIRTF; PERFORMANCE; GALAXIES; CALIBRATION; ASTRONOMY
AB The Infrared Array Camera (IRAC) is one of three focal plane instruments on the Spitzer Space Telescope. IRAC is a four-channel camera that obtains simultaneous broadband images at 3.6, 4.5, 5.8, and 8.0 mum. Two nearly adjacent 5.'2; 5.'2 fields of view in the focal plane are viewed by the four channels in pairs ( 3.6 and 5.8 mum; 4.5 and 8 mum). All four detector arrays in the camera are 256 x 256 pixels in size, with the two shorter wavelength channels using InSb and the two longer wavelength channels using Si: As IBC detectors. IRAC is a powerful survey instrument because of its high sensitivity, large field of view, and four-color imaging. This paper summarizes the in-flight scientific, technical, and operational performance of IRAC.
C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA.
Inst Astron, Hilo, HI 96720 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
Raytheon Infrared Operat, Goleta, CA 93117 USA.
Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA.
RP Fazio, GG (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA.
EM gfazio@cfa.harvard.edu
RI Moseley, Harvey/D-5069-2012; Barmby, Pauline/I-7194-2016;
OI Barmby, Pauline/0000-0003-2767-0090; Hora, Joseph/0000-0002-5599-4650;
Arendt, Richard/0000-0001-8403-8548; Reach, William/0000-0001-8362-4094
NR 27
TC 2007
Z9 2009
U1 5
U2 57
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 10
EP 17
DI 10.1086/422843
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300002
ER
PT J
AU Houck, JR
Roellig, TL
van Cleve, J
Forrest, WJ
Herter, T
Lawrence, CR
Matthews, K
Reitsema, HJ
Soifer, BT
Watson, DM
Weedman, D
Huisjen, M
Troeltzsch, J
Barry, DJ
Bernard-Salas, J
Blacken, CE
Brandl, BR
Charmandaris, V
Devost, D
Gull, GE
Hall, P
Henderson, CP
Higdon, SJU
Pirger, BE
Schoenwald, J
Sloan, GC
Uchida, KI
Appleton, PN
Armus, L
Burgdorf, MJ
Fajardo-Acosta, SB
Grillmair, CJ
Ingalls, JG
Morris, PW
Teplitz, HI
AF Houck, JR
Roellig, TL
van Cleve, J
Forrest, WJ
Herter, T
Lawrence, CR
Matthews, K
Reitsema, HJ
Soifer, BT
Watson, DM
Weedman, D
Huisjen, M
Troeltzsch, J
Barry, DJ
Bernard-Salas, J
Blacken, CE
Brandl, BR
Charmandaris, V
Devost, D
Gull, GE
Hall, P
Henderson, CP
Higdon, SJU
Pirger, BE
Schoenwald, J
Sloan, GC
Uchida, KI
Appleton, PN
Armus, L
Burgdorf, MJ
Fajardo-Acosta, SB
Grillmair, CJ
Ingalls, JG
Morris, PW
Teplitz, HI
TI The Infrared Spectrograph (IRS) on the Spitzer Space Telescope
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE infrared : general; instrumentation : spectrographs; space vehicles :
instruments
ID SIRTF
AB The Infrared Spectrograph (IRS) is one of three science instruments on the Spitzer Space Telescope. The IRS comprises four separate spectrograph modules covering the wavelength range from 5.3 to 38 mum with spectral resolutions, R = lambda/Deltalambda approximate to 90 and 600, and it was optimized to take full advantage of the very low background in the space environment. The IRS is performing at or better than the prelaunch predictions. An autonomous target acquisition capability enables the IRS to locate the mid-infrared centroid of a source, providing the information so that the spacecraft can accurately offset that centroid to a selected slit. This feature is particularly useful when taking spectra of sources with poorly known coordinates. An automated data-reduction pipeline has been developed at the Spitzer Science Center.
C1 Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Ball Aerosp & Technol Corp, Boulder, CO 80301 USA.
Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA.
CALTECH, Palomar Observ, Pasadena, CA 91125 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Leiden Univ, NL-2300 RA Leiden, Netherlands.
Observ Paris, Chercheur Associe, F-75014 Paris, France.
CALTECH, IPAC, NASA, Herschel Sci Ctr, Pasadena, CA 91125 USA.
RP Houck, JR (reprint author), Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
EM jrh13@cornell.edu
RI Charmandaris, Vassilis/A-7196-2008;
OI Charmandaris, Vassilis/0000-0002-2688-1956; Appleton,
Philip/0000-0002-7607-8766
NR 16
TC 1088
Z9 1089
U1 0
U2 12
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 18
EP 24
DI 10.1086/423134
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300003
ER
PT J
AU Fazio, GG
Ashby, MLN
Barmby, P
Hora, JL
Huang, JS
Pahre, MA
Wang, Z
Willner, SP
Arendt, RG
Moseley, SH
Brodwin, M
Eisenhardt, P
Stern, D
Tollestrup, EV
Wright, EL
AF Fazio, GG
Ashby, MLN
Barmby, P
Hora, JL
Huang, JS
Pahre, MA
Wang, Z
Willner, SP
Arendt, RG
Moseley, SH
Brodwin, M
Eisenhardt, P
Stern, D
Tollestrup, EV
Wright, EL
TI Number counts at 3 mu m < lambda < 10 mu m from the Spitzer Space
Telescope
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE dust, extinction; galaxies : fundamental parameters; infrared :
galaxies; ISM : lines and bands; stars : formation
ID HUBBLE-DEEP-FIELD; EXTRAGALACTIC SOURCE COUNTS; GALAXY COUNTS; REDSHIFT
SURVEY; DATA REDUCTION; INFRARED SKY; K-BAND; MICRON; EVOLUTION;
PHOTOMETRY
AB Infrared source counts at wavelengths 3 mum < λ < 10 mum cover more than 10 mag in source brightness, reach 4 orders of magnitude in surface density, and reach an integrated surface density of 10(5) sources deg(-2). At m < 14 mag, most of the sources are Galactic stars, in agreement with models. After removal of Galactic stars, galaxy counts are consistent with what few measurements exist at nearby wavelengths. At 3.6 and 4.5 μm, the galaxy counts follow the expectations of a Euclidean world model down to &SIM;16 mag and drop below the Euclidean curve for fainter magnitudes. Counts at these wavelengths begin to show decreasing completeness around 19.5 mag. At 5.8 and 8 μm, the counts relative to a Euclidean world model show a large excess at bright magnitudes. This is probably because local galaxies emit strongly in the aromatic dust ("polycyclic aromatic hydrocarbon'') features. The counts at 3.6 μm resolve less than 50% of the cosmic infrared background at that wavelength.
C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Hawaii, Inst Astron, Hilo, HI 96720 USA.
Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
RP Fazio, GG (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA.
EM gfazio@cfa.harvard.edu; mashby@cfa.harvard.edu; pbarmby@cfa.harvard.edu;
jhora@cfa.harvard.edu; jhuang@cfa.harvard.edu; mpahre@cfa.harvard.edu;
zwang@cfa.harvard.edu; swillner@cfa.harvard.edu;
arendt@stars.gsfc.nasa.gov; moseley@stars.fsfc.nasa.gov;
Mark.Brodwin@jpl.nasa.gov; peisenhardt@sirtfweb.jpl.nasa.gov;
stern@ipac.caltech.edu; tolles@ifa.hawaii.edu;
wright@notw33.astro.ucla.edu
RI Moseley, Harvey/D-5069-2012; Barmby, Pauline/I-7194-2016
OI Barmby, Pauline/0000-0003-2767-0090
NR 36
TC 207
Z9 207
U1 0
U2 4
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 39
EP 43
DI 10.1086/422585
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300007
ER
PT J
AU Eisenhardt, PR
Stern, D
Brodwin, M
Fazio, GG
Rieke, GH
Rieke, MJ
Werner, MW
Wright, EL
Allen, LE
Arendt, RG
Ashby, MLN
Barmby, P
Forrest, WJ
Hora, JL
Huang, JS
Huchra, J
Pahre, MA
Pipher, JL
Reach, WT
Smith, HA
Stauffer, JR
Wang, Z
Willner, SP
Brown, MJI
Dey, A
Jannuzi, BT
Tiede, GP
AF Eisenhardt, PR
Stern, D
Brodwin, M
Fazio, GG
Rieke, GH
Rieke, MJ
Werner, MW
Wright, EL
Allen, LE
Arendt, RG
Ashby, MLN
Barmby, P
Forrest, WJ
Hora, JL
Huang, JS
Huchra, J
Pahre, MA
Pipher, JL
Reach, WT
Smith, HA
Stauffer, JR
Wang, Z
Willner, SP
Brown, MJI
Dey, A
Jannuzi, BT
Tiede, GP
TI The Infrared Array Camera (IRAC) shallow survey
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE infrared : galaxies; infrared : stars; surveys
ID DIGITAL SKY SURVEY; GALAXY; FIELD; PHOTOMETRY; QUASARS
AB The Infrared Array Camera (IRAC) shallow survey covers 8.5 deg(2) in the NOAO Deep Wide-Field Survey in Bootes with three or more 30 s exposures per position. An overview of the survey design, reduction, calibration, star-galaxy separation, and initial results is provided. The survey includes approximate to370,000, 280,000, 38,000, and 34,000 sources brighter than the 5 sigma limits of 6.4, 8.8, 51, and 50 muJy at 3.6, 4.5, 5.8, and 8 mum, respectively, including some with unusual spectral energy distributions.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
Univ Calif Los Angeles, Los Angeles, CA 90095 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Rochester, Rochester, NY 14627 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Natl Opt Astron Observ, Tucson, AZ 85726 USA.
Bowling Green State Univ, Bowling Green, OH 43403 USA.
RP Eisenhardt, PR (reprint author), CALTECH, Jet Prop Lab, MC 169-327,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM peisenhardt@sirtfweb.jpl.nasa.gov
RI Brown, Michael/B-1181-2015; Barmby, Pauline/I-7194-2016;
OI Brown, Michael/0000-0002-1207-9137; Barmby, Pauline/0000-0003-2767-0090;
Arendt, Richard/0000-0001-8403-8548; Reach, William/0000-0001-8362-4094
NR 24
TC 162
Z9 162
U1 0
U2 4
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 48
EP 53
DI 10.1086/423180
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300009
ER
PT J
AU Lonsdale, C
Polletta, MD
Surace, J
Shupe, D
Fang, F
Xu, CK
Smith, HE
Siana, B
Rowan-Robinson, M
Babbedge, T
Oliver, S
Pozzi, F
Davoodi, P
Owen, F
Padgett, D
Frayer, D
Jarrett, T
Masci, F
O'Linger, J
Conrow, T
Farrah, D
Morrison, G
Gautier, N
Franceschini, A
Berta, S
Perez-Fournon, I
Hatziminaoglou, E
Afonso-Luis, A
Dole, H
Stacey, G
Serjeant, S
Pierre, M
Griffin, M
Puetter, R
AF Lonsdale, C
Polletta, MD
Surace, J
Shupe, D
Fang, F
Xu, CK
Smith, HE
Siana, B
Rowan-Robinson, M
Babbedge, T
Oliver, S
Pozzi, F
Davoodi, P
Owen, F
Padgett, D
Frayer, D
Jarrett, T
Masci, F
O'Linger, J
Conrow, T
Farrah, D
Morrison, G
Gautier, N
Franceschini, A
Berta, S
Perez-Fournon, I
Hatziminaoglou, E
Afonso-Luis, A
Dole, H
Stacey, G
Serjeant, S
Pierre, M
Griffin, M
Puetter, R
TI First insights into the Spitzer Wide-area Infrared Extragalactic Legacy
Survey (SWIRE) galaxy populations
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE galaxies : evolution; infrared : galaxies
ID PHOTOMETRIC REDSHIFTS; EVOLUTION; QUASARS; MODELS; DUSTY
AB We characterize the Spitzer Wide-area Infrared Extragalactic Legacy Survey (SWIRE) galaxy populations in the SWIRE validation field within the Lockman Hole, based on the 3.6 - 24 mum Spitzer data and deep U, g', r', i' optical imaging within an area similar to 1/3 deg(2) for similar to 16,000 Spitzer SWIRE sources. The entire SWIRE survey will discover over 2.3 million galaxies at 3.6 mum and almost 350,000 at 24 mum; similar to 70,000 of these will be five-band 3.6-24 mum detections. The colors cover a broad range, generally well represented by redshifted spectral energy distributions of known galaxy populations; however, significant samples of unusually blue objects in the [3.6] - [4.5] color are found, as well as many objects very red in the 3.6 - 24 mum mid-IR. Nine of these are investigated and are interpreted as star-forming systems, starbursts, and active galactic nuclei (AGNs) from z = 0.37 to 2.8, with luminosities from L-IR = 10(10.3) to 10(13.7) L-..
C1 CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA.
Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA.
Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Astrophys Grp, London SW7 2BW, England.
Univ Sussex, CPES, Ctr Astron, Brighton BN1 9QJ, E Sussex, England.
Natl Radio Astron Observ, Socorro, NM 87801 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Padua, Dipartimento Astron, I-35122 Padua, Italy.
Inst Astrofis Canarias, Tenerife 38200, Spain.
Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France.
Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
Univ Kent, Sch Phys Sci, Ctr Astron & Planetary Sci, Canterbury CT2 7NZ, Kent, England.
CEA, DSM, DAPNIA, Serv Astrophys, F-91191 Gif Sur Yvette, France.
Univ Wales Coll Cardiff, Dept Phys & Astron, Cardiff CF24 3YB, S Glam, Wales.
RP Lonsdale, C (reprint author), CALTECH, Ctr Infrared Proc & Anal, MC 100-22, Pasadena, CA 91125 USA.
RI Oliver, Seb/A-2479-2013;
OI Oliver, Seb/0000-0001-7862-1032; Polletta, Maria del
Carmen/0000-0001-7411-5386
NR 15
TC 144
Z9 144
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 54
EP 59
DI 10.1086/423206
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300010
ER
PT J
AU Chary, R
Casertano, S
Dickinson, ME
Ferguson, HC
Eisenhardt, PRM
Elbaz, D
Grogin, NA
Moustakas, LA
Reach, WT
Yan, H
AF Chary, R
Casertano, S
Dickinson, ME
Ferguson, HC
Eisenhardt, PRM
Elbaz, D
Grogin, NA
Moustakas, LA
Reach, WT
Yan, H
TI The nature of faint 24 micron sources seen in Spitzer Space Telescope
observations of ELAIS-N1
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE galaxies : evolution; galaxies : high-redshift; infrared : galaxies
ID GALAXY EVOLUTION; SOURCE COUNTS; HIGH-REDSHIFT; FIELD; IMAGES; DUST
AB The Spitzer Space Telescope has undertaken the deepest ever observations of the 24 mum sky in the European Large Area ISO Survey (ELAIS-N1) field, with the Multiband Imaging Photometer (MIPS) instrument, as part of GOODS Science Verification observations. We present completeness- corrected extragalactic source counts down to 24 mum flux densities of 20 muJy (30% completeness), a factor of 10,000 more sensitive than IRAS. The shape of the counts confirms model predictions for a strong evolution of the infrared luminosity function between redshifts of 0 and 1 and suggests a flattening in the evolutionary parameters at higher redshifts. Models that fit the counts indicate that luminous infrared galaxies [10(11) L-. < L8-1000 mu m < 10(12) L-.] in the redshift range 0.5< z< 2.5 constitute greater than 60% of 24 mum sources seen in the flux range 20 muJy< S-nu < 1000 muJy. At least 85%, and possibly all, of the 24 mum sources have a counterpart in the Infrared Array Camera (IRAC) 3.6 and 4.5 mum near-infrared channels, consistent with the expected spectral energy distribution of infrared luminous galaxies at moderate redshift. The similarity between the observed mid-infrared to near-infrared flux ratios of the Spitzer-detected sources and the 15 mum/HK-band flux ratios of the ISOCAM 15 mum sources seen in the Hubble Deep Field - North strongly suggests that faint 24 mum sources are high-redshift analogs of ISOCAM 15 mum sources and that they have the potential to provide an evolutionary connection between the well-studied z similar to 3 Lyman break galaxy population and the dusty starburst galaxies seen at z similar to 1.
C1 CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Space Telescope Sci Inst, Baltimore, MD 21218 USA.
Natl Opt Astron Observ, Tucson, AZ 85719 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
CEA Saclay, Serv Astrophys, DAPNIA, F-91191 Gif Sur Yvette, France.
Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA.
RP CALTECH, Spitzer Sci Ctr, MC 220-6, Pasadena, CA 91125 USA.
EM rchary@caltech.edu
OI Moustakas, Leonidas/0000-0003-3030-2360; Reach,
William/0000-0001-8362-4094
NR 18
TC 100
Z9 100
U1 0
U2 4
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
EI 1538-4365
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 80
EP 86
DI 10.1086/423307
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300015
ER
PT J
AU Barmby, P
Huang, JS
Fazio, GG
Surace, JA
Arendt, RG
Hora, JL
Pahre, MA
Adelberger, KL
Eisenhardt, P
Erb, DK
Pettini, M
Reach, WT
Reddy, NA
Shapley, AE
Steidel, CC
Stern, D
Wang, Z
Willner, SP
AF Barmby, P
Huang, JS
Fazio, GG
Surace, JA
Arendt, RG
Hora, JL
Pahre, MA
Adelberger, KL
Eisenhardt, P
Erb, DK
Pettini, M
Reach, WT
Reddy, NA
Shapley, AE
Steidel, CC
Stern, D
Wang, Z
Willner, SP
TI Deep mid-infrared observations of Lyman break galaxies
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE galaxies : high-redshift; galaxies : stellar content; infrared :
galaxies
ID REDSHIFT Z-SIMILAR-TO-3; EVOLUTION; COUNTS
AB As part of the in-orbit checkout activities for the Spitzer Space Telescope, the Infrared Array Camera (IRAC) team carried out a deep observation ( average integration time similar to 8 hr) of a field surrounding the bright QSO HS 1700+ 6416. This field contains several hundred z similar to 3 Lyman break galaxy (LBG) candidates, and we report here on their mid-infrared properties, including the IRAC detection rate, flux densities, and colors, and the results of fitting population synthesis models to the optical, near-infrared, and IRAC magnitudes. The results of the model fitting show that previous optical/near-infrared studies of LBGs were not missing large, hidden old stellar populations. The LBG candidates' properties are consistent with those of massive star-forming galaxies at z similar to 3. Other IRAC sources in the same field have similar properties, so IRAC selection may prove to be a promising method of finding additional high-redshift galaxies.
C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
NASA, Sci Syst & Applicat Inc, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Observ Carnegie Inst Washington, Pasadena, CA 91101 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England.
Univ Calif Berkeley, Dept Astron, Berkeley, CA 84720 USA.
RP Barmby, P (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA.
EM pbarmby@cfa.harvard.edu
RI Barmby, Pauline/I-7194-2016;
OI Barmby, Pauline/0000-0003-2767-0090; Hora, Joseph/0000-0002-5599-4650;
Arendt, Richard/0000-0001-8403-8548; Reach, William/0000-0001-8362-4094
NR 21
TC 41
Z9 41
U1 0
U2 3
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 97
EP 102
DI 10.1086/422712
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300018
ER
PT J
AU Soifer, BT
Charmandaris, V
Brandl, BR
Armus, L
Appleton, PN
Burgdorf, MJ
Devost, D
Herter, T
Higdon, SJU
Higdon, JL
Houck, JR
Lawrence, CR
Morris, PW
Teplitz, HI
Uchida, KI
van Cleve, J
Weedman, D
AF Soifer, BT
Charmandaris, V
Brandl, BR
Armus, L
Appleton, PN
Burgdorf, MJ
Devost, D
Herter, T
Higdon, SJU
Higdon, JL
Houck, JR
Lawrence, CR
Morris, PW
Teplitz, HI
Uchida, KI
van Cleve, J
Weedman, D
TI Spitzer Infrared Spectrograph (IRS) observations of the redshift 3.91
quasar APM 08279+5255
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE galaxies : high-redshift; quasars : emission lines; quasars : individual
(APM 08279+5255); techniques : spectroscopic
ID ABSORPTION-LINE QUASAR; ACTIVE GALACTIC NUCLEI; APM 08279+5255;
ENERGY-DISTRIBUTIONS; EMISSION; SPECTROSCOPY; SPECTRUM; TORI
AB The Infrared Spectrograph (IRS) on board the Spitzer Space Telescope has been used to obtain low- and moderate-resolution spectra of the dust- and gas-rich quasar APM 08279+5255 (z = 3.91). Broad Paalpha and Pabeta recombination lines of hydrogen were detected at wavelengths of 9.235 and 6.315 mum, respectively, as well as a strong, red continuum that is a smooth power law over the observed (rest-frame) wavelength range 5.3-35 mum (1.08-7.1 mum). The observed Paalpha/Pabeta line flux ratio of 1>05 +/- 0>2 is far from the case B value of similar to2 and simple models of high-density, high optical depth ionized-gas regions (similar to1.8). This deviation is opposite in sense to the expected effect of reddening. No evidence is found in the spectrum for either the 3.3 or the 6.2 mum emission features usually attributed to aromatic hydrocarbons in gas-rich galaxies in the local universe. This is consistent with the high-luminosity active galactic nucleus (AGN) nature of APM 08279+5255.
C1 CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
Observ Paris, F-75014 Paris, France.
Leiden Univ, NL-2300 RA Leiden, Netherlands.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Ball Aerosp Technol Corp, Boulder, CO 80301 USA.
RP Soifer, BT (reprint author), CALTECH, Spitzer Sci Ctr, MC 314-6, Pasadena, CA 91125 USA.
EM bts@ipac.caltech.edu; vassilis@astro.cornell.edu;
brandl@strw.leidenuniv.nl; lee@ipac.caltech.edu; apple@ipac.caltech.edu;
burgdorf@ipac.caltech.edu; devost@astro.cornell.edu; tlh10@cornell.edu;
sjuh@isc.astro.cornell.edu; jhigdon@astro.cornell.edu;
jrh13@cornell.edu; charles.r.lawrence@jpl.nasa.gov;
pmorris@ipac.caltech.edu; hit@ipac.caltech.edu;
kuchida@astro.cornell.edu; jvanclev@ball.com;
dweedman@isc.astro.cornell.edu
RI Charmandaris, Vassilis/A-7196-2008;
OI Charmandaris, Vassilis/0000-0002-2688-1956; Appleton,
Philip/0000-0002-7607-8766
NR 22
TC 23
Z9 23
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 151
EP 154
DI 10.1086/421977
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300028
ER
PT J
AU Alonso-Herrero, A
Perez-Gonzalez, PG
Rigby, J
Rieke, GH
Le Floc'h, E
Barmby, P
Page, MJ
Papovich, C
Dole, H
Egami, E
Huang, JS
Rigopoulou, D
Cristobal-Hornillos, D
Eliche-Moral, C
Balcells, M
Prieto, M
Erwin, P
Engelbracht, CW
Gordon, KD
Werner, M
Willner, SP
Fazio, GG
Frayer, D
Hines, D
Kelly, D
Latter, W
Misselt, K
Miyazaki, S
Morrison, J
Rieke, MJ
Wilson, G
AF Alonso-Herrero, A
Perez-Gonzalez, PG
Rigby, J
Rieke, GH
Le Floc'h, E
Barmby, P
Page, MJ
Papovich, C
Dole, H
Egami, E
Huang, JS
Rigopoulou, D
Cristobal-Hornillos, D
Eliche-Moral, C
Balcells, M
Prieto, M
Erwin, P
Engelbracht, CW
Gordon, KD
Werner, M
Willner, SP
Fazio, GG
Frayer, D
Hines, D
Kelly, D
Latter, W
Misselt, K
Miyazaki, S
Morrison, J
Rieke, MJ
Wilson, G
TI The nature of luminous X-ray sources with mid-infrared counterparts
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE galaxies : active; galaxies : fundamental parameters; infrared :
galaxies; X-rays : galaxies
ID SPECTRAL ENERGY-DISTRIBUTIONS; SPITZER-SPACE-TELESCOPE; ARRAY CAMERA
IRAC; LOCKMAN HOLE; DEEP SURVEY; GALAXIES; FIELD; EVOLUTION; COUNTS;
GROTH
AB We investigate the luminous X-ray sources in the Lockman Hole (LH) and the extended Groth strip (EGS) detected at 24 mum using the Multiband Imaging Photometer (MIPS) and also with the Infrared Array Camera (IRAC) on board the Spitzer Space Telescope. We assemble optical/infrared spectral energy distributions (SEDs) for 45 X-ray/24 mum sources in the EGS and LH. Only about one-quarter of the hard X-ray/24 mum sources show pure type 1 active galactic nucleus (AGN) SEDs. More than half of the X-ray/24 mum sources have stellar emission-dominated or obscured SEDs, similar to those of local type 2 AGN and spiral/starburst galaxies. One-third of the sources detected in hard X-rays do not have a 24 mum counterpart. Two such sources in the LH have SEDs resembling those of S0/elliptical galaxies. The broad variety of SEDs in the optical-to-Spitzer bands of X-ray-selected AGNs means that AGNs selected according to the behavior in the optical/infrared will have to be supplemented by other kinds of data (e.g., X-ray) to produce unbiased samples of AGNs.
C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
CSIC, Inst Estructura Mat, E-28006 Madrid, Spain.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England.
Univ Paris 11, Inst Astrophys Spatiale, F-91405 Orsay, France.
Univ Oxford, Dept Astrophys, Oxford OX1 3RH, England.
Inst Astrofis Canarias, E-38200 San Cristobal la Laguna, Spain.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Natl Astron Observ Japan, Subaru Telescope, Hilo, HI 96720 USA.
RP Alonso-Herrero, A (reprint author), Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA.
EM aalonso@as.arizona.edu
RI Rigby, Jane/D-4588-2012; Barmby, Pauline/I-7194-2016; Perez-Gonzalez,
Pablo/J-2871-2016; Alonso-Herrero, Almudena/H-1426-2015;
OI Rigby, Jane/0000-0002-7627-6551; Barmby, Pauline/0000-0003-2767-0090;
Perez-Gonzalez, Pablo/0000-0003-4528-5639; Alonso-Herrero,
Almudena/0000-0001-6794-2519; Erwin, Peter/0000-0003-4588-9555
NR 30
TC 34
Z9 34
U1 0
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 155
EP 159
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300029
ER
PT J
AU Spoon, HWW
Armus, L
Cami, J
Tielens, AGGM
Chiar, JE
Peeters, E
Keane, JV
Charmandaris, V
Appleton, PN
Teplitz, HI
Burgdorf, MJ
AF Spoon, HWW
Armus, L
Cami, J
Tielens, AGGM
Chiar, JE
Peeters, E
Keane, JV
Charmandaris, V
Appleton, PN
Teplitz, HI
Burgdorf, MJ
TI Fire and ice: Spitzer Infrared Spectrograph (IRS) mid-infrared
spectroscopy of IRAS F00183-7111
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE galaxies : individual (IRAS F00183-7111); galaxies : ISM; infrared :
galaxies
ID HII-REGIONS; GALAXIES; SPECTRA; CONTINUUM; FEATURES; ISOCAM; DUST
AB We report the detection of strong absorption and weak emission features in the 4-27 mum Spitzer Infrared Spectrograph (IRS) spectrum of the distant ultraluminous infrared galaxy IRAS F00183-7111 (z = 0.327). The absorption features of CO2 and CO gas, water ice, hydrocarbons, and silicates are indicative of a strongly obscured (A(9.6) greater than or equal to 5.4; A(V) greater than or equal to 90) and complex line of sight through both the hot diffuse interstellar medium and shielded cold molecular clouds toward the nuclear power source. From the profile of the 4.67 mum CO fundamental vibration mode, we deduce that the absorbing gas is dense (n similar to 10(6) cm(-3)) and warm ( 720 K) and has a CO column density of similar to10(19.5) cm(-2), equivalent to N-H similar to 10(23.5) cm(-2). The high temperature and density, as well as the small inferred size (<0.03 pc), locates this absorbing gas close to the power source of this region. Weak emission features of molecular hydrogen, polycyclic aromatic hydrocarbons (PAHs), and Ne+, likely associated with star formation, are detected against the 9.7 mu m silicate feature, indicating an origin away from the absorbing region. Based on the 11.2 mu m PAH flux, we estimate the star formation component to be responsible for up to 30% of the IR luminosity of the system. While our mid-infrared spectrum shows no telltale signs of active galactic nucleus (AGN) activity, the similarities to the mid-infrared spectra of deeply obscured sources ( e. g., NGC 4418) and AGN hot dust (e.g., NGC 1068), as well as evidence from other wavelength regions, suggest that the power source hiding behind the optically thick dust screen may well be a buried AGN.
C1 Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Univ Groningen, Space Res Org Netherlands, Natl Inst Space Res, NL-9700 AV Groningen, Netherlands.
Univ Groningen, Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
SETI Inst, Mountain View, CA 94043 USA.
RP Spoon, HWW (reprint author), Cornell Univ, Dept Astron, 219 Space Sci Bldg, Ithaca, NY 14853 USA.
EM spoon@astro.cornell.edu
RI Charmandaris, Vassilis/A-7196-2008;
OI Charmandaris, Vassilis/0000-0002-2688-1956; Appleton,
Philip/0000-0002-7607-8766
NR 24
TC 111
Z9 111
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 184
EP 187
DI 10.1086/422813
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300035
ER
PT J
AU Smith, JDT
Dale, DA
Armus, L
Draine, BT
Hollenbach, DJ
Roussel, H
Helou, G
Kennicutt, RC
Li, A
Bendo, GJ
Calzetti, D
Engelbracht, CW
Gordon, KD
Jarrett, TH
Kewley, L
Leitherer, C
Malhotra, S
Meyer, MJ
Murphy, EJ
Regan, MW
Rieke, GH
Rieke, MJ
Thornley, MD
Walter, F
Wolfire, MG
AF Smith, JDT
Dale, DA
Armus, L
Draine, BT
Hollenbach, DJ
Roussel, H
Helou, G
Kennicutt, RC
Li, A
Bendo, GJ
Calzetti, D
Engelbracht, CW
Gordon, KD
Jarrett, TH
Kewley, L
Leitherer, C
Malhotra, S
Meyer, MJ
Murphy, EJ
Regan, MW
Rieke, GH
Rieke, MJ
Thornley, MD
Walter, F
Wolfire, MG
TI Mid-infrared IRS spectroscopy of NGC 7331: A first look at the Spitzer
Infrared Nearby Galaxies Survey (SINGS) Legacy
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE dust, extinction; galaxies : individual (NGC 7331); galaxies : ISM;
infrared : galaxies; line : identification; techniques : spectroscopic
ID O IV EMISSION; INTERSTELLAR-MEDIUM; STARBURST GALAXIES
AB The nearby spiral galaxy NGC 7331 was spectrally mapped from 5 to 38 mum using all modules of Spitzer's Infrared Spectrograph (IRS). A strong new dust emission feature, presumed due to polycyclic aromatic hydrocarbons, was discovered at 17.1 mum. The feature's intensity is nearly half that of the ubiquitous 11.3 mum band. The 7-14 mum spectral maps revealed significant variation in the 7.7 and 11.3 mum PAH features between the stellar ring and nucleus. Weak [O IV] 25.9 mum line emission was found to be centrally concentrated in the nucleus, with an observed strength of over 10% of the combined neon line flux, indicating an AGN or unusually active massive star photoionization. Two [S III] lines fix the characteristic electron density in the H II regions at n(e) less than or similar to 200 cm(-3). Three detected H-2 rotational lines, tracing warm molecular gas, together with the observed IR continuum, are difficult to match with standard photodissociation region (PDR) models. Either additional PDR heating or shocks are required to simultaneously match lines and continuum.
C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Princeton Univ Observ, Princeton, NJ 08544 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
CALTECH, Pasadena, CA 91101 USA.
Space Telescope Sci Res Inst, Baltimore, MD 21218 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Yale Univ, Dept Astron, New Haven, CT 06520 USA.
Bucknell Univ, Dept Phys, Lewisburg, PA 17837 USA.
Natl Radio Astron Observ, Socorro, NM 87801 USA.
Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
RP Smith, JDT (reprint author), Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
EM jdsmith@as.arizona.edu
OI Draine, Bruce/0000-0002-0846-936X
NR 19
TC 78
Z9 78
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 199
EP 203
DI 10.1086/423133
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300038
ER
PT J
AU Regan, MW
Thornley, MD
Bendo, GJ
Draine, BT
Li, AG
Dale, DA
Engelbracht, CW
Kennicutt, RC
Armus, L
Calzetti, D
Gordon, KD
Helou, G
Hollenbach, DJ
Jarrett, TH
Kewley, LJ
Leitherer, C
Malhotra, S
Meyer, M
Misselt, KA
Morrison, JE
Murphy, EJ
Muzerolle, J
Rieke, GH
Rieke, MJ
Roussel, H
Smith, JDT
Walter, F
AF Regan, MW
Thornley, MD
Bendo, GJ
Draine, BT
Li, AG
Dale, DA
Engelbracht, CW
Kennicutt, RC
Armus, L
Calzetti, D
Gordon, KD
Helou, G
Hollenbach, DJ
Jarrett, TH
Kewley, LJ
Leitherer, C
Malhotra, S
Meyer, M
Misselt, KA
Morrison, JE
Murphy, EJ
Muzerolle, J
Rieke, GH
Rieke, MJ
Roussel, H
Smith, JDT
Walter, F
TI Spitzer Infrared Nearby Galaxies Survey (SINGS) imaging of NGC 7331: A
panchromatic view of a ringed galaxy
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE dust, extinction; galaxies : individual (NGC 7331); galaxies : ISM;
galaxies : structure; infrared : galaxies
ID STAR-FORMING GALAXIES; INTERSTELLAR DUST; NGC 7331; EMISSION FEATURES;
SPIRAL GALAXIES; KEY PROJECT; BIMA SURVEY; CLOUD; TELESCOPE; SPECTRA
AB Well-resolved infrared observations of nearby galaxies are of fundamental importance to the study of the processes that affect galactic evolution. In this paper we report on the first imaging results from the Spitzer Infrared Nearby Galaxies Survey ( SINGS) using observations of the Sb galaxy NGC 7331. We present images of NGC 7331 over a large range of wavelengths that allow us to compare the distributions of gas, stars, and dust in unprecedented detail. As an example of the types of information that the full SINGS will provide, we use three methods to determine that the interstellar medium mass in the ring of NGC 7331 is similar to5 x 10(9) M-circle dot. We also present the first images showing emission from small hot (similar to1000 K) dust grains, but we show that these dust grains contribute only a small fraction of the integrated 4.5 mum emission from NGC 7331.
C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA.
Bucknell Univ, Dept Phys, Lewisburg, PA 17837 USA.
Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
Princeton Univ Observ, Princeton, NJ 08544 USA.
Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
CALTECH, Pasadena, CA 91101 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Yale Univ, Dept Astron, New Haven, CT 06520 USA.
Natl Radio Astron Observ, Socorro, NM 87801 USA.
RP Regan, MW (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA.
EM mregan@stsci.edu
OI Draine, Bruce/0000-0002-0846-936X
NR 28
TC 58
Z9 58
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 204
EP 210
DI 10.1086/423204
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300039
ER
PT J
AU Nguyen, HT
Kallivayalil, N
Werner, MW
Alcock, C
Patten, BM
Stern, D
AF Nguyen, HT
Kallivayalil, N
Werner, MW
Alcock, C
Patten, BM
Stern, D
TI Spitzer Space Telescope observations of the aftermath of microlensing
event MACHO-LMC-5
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE gravitational lensing; infrared : stars; Magellanic Clouds
ID LARGE-MAGELLANIC-CLOUD; INTERVENING STELLAR POPULATION; LOW-MASS STARS;
MILKY-WAY; MACHO PROJECT; GALACTIC HALO; LUMINOSITY; DARK; CONSTRAINTS
AB We have carried out photometry of the microlensing event MACHO-LMC-5 with Spitzer Infrared Array Camera (IRAC) 10 years after the magnification of the LMC source star was recorded. This event is unique in the annals of gravitational microlensing: the lensing star itself has been observed using the Hubble Space Telescope ( once with WFPC2 and twice with ACS/HRC). Since the separation between the source and lens at the epoch of the Spitzer observations was similar to0."24, the two stars cannot be resolved in the Spitzer images. However, the IRAC photometry clearly establishes that the lens is an M5 dwarf star from its infrared excess, which in turn yields a mass of similar to0.2 M-circle dot. This demonstrates the potential of Spitzer to detect the lenses in other gravitational microlensing events.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Penn, Dept Phys & Astron, David Rittenhouse Lab, Philadelphia, PA 19104 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
RP Nguyen, HT (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM hien.t.nguyen@jpl.nasa.gov; nitya@student.physics.upenn.edu;
mwerner@sirtfweb.jpl.nasa.gov; alcock@hep.vpenn.edu;
bpatten@cfa.harvard.edu; stern@zwolfkinder.jpl.nasa.gov
NR 33
TC 11
Z9 11
U1 0
U2 2
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 266
EP 270
DI 10.1086/422506
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300049
ER
PT J
AU Gorjian, V
Werner, MW
Mould, JR
Gordon, KD
Muzzerole, J
Morrison, J
Surace, JM
Rebull, LM
Hurt, RL
Smith, RC
Points, SD
Aguilera, C
De Buizer, JM
Packham, C
AF Gorjian, V
Werner, MW
Mould, JR
Gordon, KD
Muzzerole, J
Morrison, J
Surace, JM
Rebull, LM
Hurt, RL
Smith, RC
Points, SD
Aguilera, C
De Buizer, JM
Packham, C
TI Infrared imaging of the Large Magellanic Cloud star-forming region
Henize 206
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE infrared : galaxies; infrared : stars; Magellanic Clouds; stars :
formation
ID GALAXIES
AB Henize 206 is a region of star formation in the Large Magellanic Cloud of the approximate scale of the Orion belt and sword. Our Spitzer Space Telescope infrared images and Cerro Tololo Inter-American Observatory (CTIO) optical images show that the region is experiencing very energetic star formation. The radiation from young stars has excited strong polycyclic aromatic hydrocarbon (PAH) emission throughout Henize 206, except on the side of the nebula with the prominent young supernova remnant. As is also seen in early Spitzer observations of M81, star formation rates calculated from Halpha for Henize 206 may miss the deeply embedded young stars, compared with star formation rates calculated from far infrared emission. For one of the highest surface brightness regions of Henize 206, we obtained snapshot exposures with the Thermal-Region Camera Spectrograph on Gemini South to explore the complex structure. A few percent of the total flux from this brightest region in Henize 206 emanates from infrared peaks of subparsec scale.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Natl Opt Astron Observ, Tucson, AZ 85726 USA.
Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Cerro Tololo Interamer Observ, La Serena, Chile.
Gemini Observ, La Serena, Chile.
Univ Florida, Dept Astron, Gainesville, FL 32611 USA.
RP Gorjian, V (reprint author), CALTECH, Jet Prop Lab, MC 169-327,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM varoujan.gorjian@jpl.nasa.gov
OI Rebull, Luisa/0000-0001-6381-515X
NR 12
TC 15
Z9 15
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 275
EP 280
DI 10.1086/422689
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300051
ER
PT J
AU Hines, DC
Rieke, GH
Gordon, KD
Rho, J
Misselt, KA
Woodward, CE
Werner, MW
Krause, O
Latter, WB
Engelbracht, CW
Egami, E
Kelly, DM
Muzerolle, J
Stansberry, JA
Su, KYL
Morrison, JE
Young, ET
Noriega-Crespo, A
Padgett, DL
Gehrz, RD
Polomski, E
Beeman, JW
Haller, EE
AF Hines, DC
Rieke, GH
Gordon, KD
Rho, J
Misselt, KA
Woodward, CE
Werner, MW
Krause, O
Latter, WB
Engelbracht, CW
Egami, E
Kelly, DM
Muzerolle, J
Stansberry, JA
Su, KYL
Morrison, JE
Young, ET
Noriega-Crespo, A
Padgett, DL
Gehrz, RD
Polomski, E
Beeman, JW
Haller, EE
TI Imaging of the supernova remnant Cassiopeia A with the multiband imaging
photometer for Spitzer (MIPS)
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE infrared : ISM; ISM : individual (Cassiopeia A); supernova remnants
ID DUST; EJECTA
AB We present new images of the supernova remnant (SNR) Cas A observed in the 24 and 70 mum bands of the Spitzer Space Telescope (Spitzer). The IR emission correlates well with the Si X-ray and optical [S II] emission but poorly with either the synchrotron-dominated radio structure or the continuum X-ray emission. The IR is therefore dominated by thermal emission from dust within the SNR and associated with emission-line gas inside the reverse shock region, confirming earlier IRAS and Infrared Space Observatory results. Supplemented by new photometric measurements from archived Midcourse Space Experiment images, we suggest stochastic heating to model the overall mid- to far-IR spectral energy distribution. The 24 and 70 mum images also reveal a counterjet to the well-known northeast jet feature imaged previously at X-ray, optical, and radio wavelengths. This IR counterjet corresponds well with (optical) fast-moving knots confirming its outflow nature. The opposing jetlike features define a symmetry axis that bisects the SNR and suggest that the supernova explosion was axisymmetric. The IR images also show a region in which the SNR forward shock appears to be propagating into a similar to650 M-circle dot molecular cloud. The new images also show other details of the surrounding ISM structure, including two groups of knots extending similar to6'-12' on either side of the SNR.
C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Univ Minnesota, Sch Phys & Astron, Dept Astron, Minneapolis, MN 55455 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA.
RP Hines, DC (reprint author), Space Sci Inst, 4750 Walnut St,Suite 205, Boulder, CO 80301 USA.
OI Su, Kate/0000-0002-3532-5580
NR 33
TC 71
Z9 71
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 290
EP 295
DI 10.1086/422583
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300054
ER
PT J
AU Werner, MW
Uchida, KI
Sellgren, K
Marengo, M
Gordon, KD
Morris, PW
Houck, JR
Stansberry, JA
AF Werner, MW
Uchida, KI
Sellgren, K
Marengo, M
Gordon, KD
Morris, PW
Houck, JR
Stansberry, JA
TI New infrared emission features and spectral variations in NGC 7023
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE dust, extinction; infrared : ISM; ISM : individual (NGC 7023); ISM :
lines and bands; ISM : molecules; reflection nebulae
ID NEBULA NGC 7023; VISUAL REFLECTION NEBULAE; MU-M; BENDING MODES; DUST;
CONTINUUM; PAHS
AB We observed the reflection nebula NGC 7023, with the Short-High module and the long-slit Short-Low and Long-Low modules of the Infrared Spectrograph on the Spitzer Space Telescope. We also present Infrared Array Camera (IRAC) and Multiband Imaging Photometer for Spitzer (MIPS) images of NGC 7023 at 3.6, 4.5, 8.0, and 24 mum. We observe the aromatic emission features (AEFs) at 6.2, 7.7, 8.6, 11.3, and 12.7 mum, plus a wealth of weaker features. We find new unidentified interstellar emission features at 6.7, 10.1, 15.8, 17.4, and 19.0 mum. Possible identifications include aromatic hydrocarbons or nanoparticles of unknown mineralogy. We see variations in relative feature strengths, central wavelengths, and feature widths, in the AEFs and weaker emission features, depending on both distance from the star and nebular position (southeast vs. northwest).
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA.
Ohio State Univ, Dept Astron, Columbus, OH 43210 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
CALTECH, Spitzer Sci Ctr, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA.
RP Werner, MW (reprint author), CALTECH, Jet Prop Lab, MC 264-767,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM sellgren@astronomy.ohio-state.edu
NR 31
TC 108
Z9 108
U1 0
U2 3
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 309
EP 314
DI 10.1086/422413
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300057
ER
PT J
AU Marston, AP
Reach, WT
Noriega-Crespo, A
Rho, J
Smith, HA
Melnick, G
Fazio, G
Rieke, G
Carey, S
Rebull, L
Muzerolle, J
Egami, E
Watson, DM
Pipher, JL
Latter, WB
Stapelfeldt, K
AF Marston, AP
Reach, WT
Noriega-Crespo, A
Rho, J
Smith, HA
Melnick, G
Fazio, G
Rieke, G
Carey, S
Rebull, L
Muzerolle, J
Egami, E
Watson, DM
Pipher, JL
Latter, WB
Stapelfeldt, K
TI DR 21: A major star formation site revealed by Spitzer
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE infrared : ISM; ISM : clouds; ISM : individual (DR 21); ISM : jets and
outflows; stars : formation
ID ULTRACOMPACT HII-REGIONS; H-II REGIONS; MOLECULAR CLOUDS; FORMING
REGIONS; CYGNUS-X; EMISSION; SPECTROSCOPY; CANDIDATES; EVOLUTION; FLOWS
AB We have obtained images of the obscured massive star-forming region DR 21 using both the Infrared Array Camera (IRAC) and Multiband Imaging Photometer for Spitzer (MIPS) instruments aboard the Spitzer Space Telescope. Our images cover an area of more than half a square degree. The unprecedented high sensitivity and resolution of both IRAC and MIPS allow us to reveal the complexity of this region for the first time. Our images show extended outflows from a dense disk of material. Previously observed molecular outflows from the center of DR 21 are clearly visible in our images and are embedded in a much larger region of diffuse filaments apparently flowing out from DR 21. Many of the point sources in the region seen by Spitzer at 8 and 24 mum are both very obscured and intrinsically red. We discuss the properties of some of these extremely red objects and indicate that they are likely to be Class I or earlier protostars. Other features observed include mid-infrared dark clouds that occasionally appear as swept up features from extremely red objects, including a 15 pc long north-south filament to the south of DR 21 itself.
C1 ESTEC, Res & Sci Support Div, NL-2201 AZ Noordwijk, Netherlands.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Harvard Univ, Dept Astron, Cambridge, MA 02138 USA.
Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Marston, AP (reprint author), ESTEC, Res & Sci Support Div, NL-2201 AZ Noordwijk, Netherlands.
EM tmarston@rssd.esa.int
RI Stapelfeldt, Karl/D-2721-2012;
OI Rebull, Luisa/0000-0001-6381-515X; Reach, William/0000-0001-8362-4094
NR 33
TC 54
Z9 54
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 333
EP 338
DI 10.1086/422817
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300061
ER
PT J
AU Noriega-Crespo, A
Morris, P
Marleau, FR
Carey, S
Boogert, A
van Dishoeck, E
Evans, NJ
Keene, J
Muzerolle, J
Stapelfeldt, K
Pontoppidan, K
Lowrance, P
Allen, L
Bourke, TL
AF Noriega-Crespo, A
Morris, P
Marleau, FR
Carey, S
Boogert, A
van Dishoeck, E
Evans, NJ
Keene, J
Muzerolle, J
Stapelfeldt, K
Pontoppidan, K
Lowrance, P
Allen, L
Bourke, TL
TI A new look at stellar outflows: Spitzer observations of the HH 46/47
system
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE infrared : ISM; ISM : Herbig-Haro objects; ISM : individual (HH 46-47);
ISM : jets and outflows; ISM : molecules; stars : formation
ID HH 46/47; INFRARED OBSERVATIONS; ABSORPTION FEATURES; BIPOLAR OUTFLOWS;
H-2 EMISSION; JET; OBJECTS; SPECTROSCOPY; BAND; FLOW
AB We present the Early Release Observations of the HH 46/47 system and HH 46 IRS 1 source, taken with the three instruments aboard the Spitzer Space Telescope. The optically invisible southwest lobe, driven by the HH 47C bow shock, is revealed in full detail by the Infrared Array Camera (IRAC) images and displays a "loop''-like morphology. Both of the mid-infrared outflow lobes are narrower than those of CO flow. We believe that the combination of emission by H-2 rotational lines [S(11)-S(4)] and some atomic lines, which fall within the IRAC passbands, are responsible for the bulk of the observed emission, although contributions from the 3.3, 6.2, and 7.7 mum polycyclic aromatic hydrocarbon emission bands cannot be ruled out. Weak spectral features corresponding to these emitters are present in the Infrared Spectrograph spectrum of the HH 47A bow shock. The spectrum of HH 46 IRS 1 shows remarkable similarities to those of high-mass protostars, which include the presence of H2O, CO2, CH4, and possibly NH3, CH3OH, and NH4+ ices. The high ice abundances and the lack of signs of thermal processing indicate that these ices in the envelope are well shielded from the powerful outflow and its cavity. Emission from the Bok globule at 24 mum is detected and displays a similar structure to that observed at 8 mum.
C1 CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
CALTECH, Dept Astron, Pasadena, CA 91125 USA.
Leiden Univ, Leiden Observ, NL-2300 RA Leiden, Netherlands.
Univ Texas, Dept Astron, Austin, TX 78712 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Harvard Smithsonian Ctr Astrophys, Submillimeter Array Project, Hilo, HI 96720 USA.
RP CALTECH, Spitzer Sci Ctr, MC 220-6, Pasadena, CA 91125 USA.
RI Stapelfeldt, Karl/D-2721-2012
NR 41
TC 109
Z9 109
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
EI 1538-4365
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 352
EP 358
PG 7
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300064
ER
PT J
AU Boogert, ACA
Pontoppidan, KM
Lahuis, F
Jorgensen, JK
Augereau, JC
Blake, GA
Brooke, TY
Brown, J
Dullemond, CP
Evans, NJ
Geers, V
Hogerheijde, MR
Kessler-Silacci, J
Knez, C
Morris, P
Noriega-Crespo, A
Schoier, FL
van Dishoeck, EF
Allen, LE
Harvey, PM
Koerner, DW
Mundy, LG
Myers, PC
Padgett, DL
Sargent, AI
Stapelfeldt, KR
AF Boogert, ACA
Pontoppidan, KM
Lahuis, F
Jorgensen, JK
Augereau, JC
Blake, GA
Brooke, TY
Brown, J
Dullemond, CP
Evans, NJ
Geers, V
Hogerheijde, MR
Kessler-Silacci, J
Knez, C
Morris, P
Noriega-Crespo, A
Schoier, FL
van Dishoeck, EF
Allen, LE
Harvey, PM
Koerner, DW
Mundy, LG
Myers, PC
Padgett, DL
Sargent, AI
Stapelfeldt, KR
TI Spitzer Space Telescope spectroscopy of ices toward low-mass embedded
protostars
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE astrochemistry; infrared : ISM; ISM : abundances; ISM : molecules; stars
: formation; stars : individual (B5 IRS 1)
ID INTERSTELLAR ICES; STARS; CO; ABUNDANCE; ENVELOPES; CORES; DUST
AB Sensitive 5-38 mum Spitzer Space Telescope and ground-based 3-5 mum spectra of the embedded low-mass protostars B5 IRS1 and HH 46 IRS show deep ice absorption bands superposed on steeply rising mid-infrared continua. The ices likely originate in the circumstellar envelopes. The CO2 bending mode at 15 mum is a particularly powerful tracer of the ice composition and processing history. Toward these protostars, this band shows little evidence for thermal processing at temperatures above 50 K. Signatures of lower temperature processing are present in the CO and OCN- bands, however. The observed CO2 profile indicates an intimate mixture with H2O, but not necessarily with CH3OH, in contrast to some high-mass protostars. This is consistent with the low CH3OH abundance derived from the ground-based L-band spectra. The CO2: H2O column density ratios are high in both B5 IRS1 and HH 46 IRS (similar to35%). Clearly, the Spitzer spectra are essential for studying ice evolution in low-mass protostellar environments and for eventually determining the relation between interstellar and solar system ices.
C1 CALTECH, Div PMA, Pasadena, CA 91125 USA.
Leiden Observ, NL-2300 RA Leiden, Netherlands.
Univ Groningen, SRON, NL-9700 AV Groningen, Netherlands.
CALTECH, Div GPS, Pasadena, CA 91125 USA.
Max Planck Inst Astrophys, D-85741 Garching, Germany.
Univ Texas, Dept Astron, Austin, TX 78712 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Smithsonian Astrophys Observ, Cambridge, MA 02138 USA.
No Arizona Univ, Dept Phys & Astron, Flagstaff, AZ 86011 USA.
Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Boogert, ACA (reprint author), CALTECH, Div PMA, MC 105-24, Pasadena, CA 91125 USA.
RI Stapelfeldt, Karl/D-2721-2012; Jorgensen, Jes Kristian/L-7936-2014;
OI Jorgensen, Jes Kristian/0000-0001-9133-8047; Dullemond,
Cornelis/0000-0002-7078-5910
NR 26
TC 95
Z9 95
U1 1
U2 6
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 359
EP 362
DI 10.1086/422556
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300065
ER
PT J
AU Watson, DM
Kemper, F
Calvet, N
Keller, LD
Furlan, E
Hartmann, L
Forrest, WJ
Chen, CH
Uchida, KI
Green, JD
Sargent, B
Sloan, GC
Herter, TL
Brandl, BR
Houck, JR
Najita, J
D'Alessio, P
Myers, PC
Barry, DJ
Hall, P
Morris, PW
AF Watson, DM
Kemper, F
Calvet, N
Keller, LD
Furlan, E
Hartmann, L
Forrest, WJ
Chen, CH
Uchida, KI
Green, JD
Sargent, B
Sloan, GC
Herter, TL
Brandl, BR
Houck, JR
Najita, J
D'Alessio, P
Myers, PC
Barry, DJ
Hall, P
Morris, PW
TI Mid-infrared spectra of Class I protostars in Taurus
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE accretion, accretion disks; circumstellar matter; infrared : stars;
stars : formation; stars : pre-main-sequence
ID AURIGA MOLECULAR CLOUD; YOUNG STELLAR OBJECTS; 2-DIMENSIONAL
RADIATIVE-TRANSFER; SPITZER-SPACE-TELESCOPE; PROTOSTELLAR ENVELOPES;
ABSORPTION FEATURES; CO OBSERVATIONS; STAR-FORMATION; DENSE CORES;
SEQUENCE
AB We present Spitzer Space Telescope Infrared Spectrograph observations in the 5.3-20 mum range of five young stellar objects in Taurus that have Class I continuum spectral energy distributions (lambdaF(lambda)alphalambda(n), ngreater than or equal to0), often taken to represent the youngest stellar objects in this star formation region. The spectra include a rich collection of broad absorption features that we identify with amorphous silicates and various ices, notably those of carbon dioxide and water. We show that the absorption features are produced mainly in the envelopes of these systems. The apparent depths of silicate and 15.2 mum CO(2) ice features vary among the objects in a manner that is consistent with a variation of inclination with respect to the line of sight, contribution to the silicate features from material throughout the envelopes, and an origin for the CO(2) ice feature in the outer parts of the envelope. Thus, these features provide new and useful constraints on models of the physical structure of Class I protostars.
C1 Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA.
Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Ithaca Coll, Dept Phys, Ithaca, NY 14850 USA.
Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands.
Natl Opt Astron Observ, Tucson, AZ 85719 USA.
Univ Nacl Autonoma Mexico, Ctr Radioastron & Astrofis, Morelia 58089, Michoacan, Mexico.
CALTECH, Spitzer Sci Ctr, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA.
RP Watson, DM (reprint author), Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA.
EM dmw@pas.rochester.edu
RI Kemper, Francisca/D-8688-2011;
OI Kemper, Francisca/0000-0003-2743-8240; Furlan, Elise/0000-0001-9800-6248
NR 33
TC 52
Z9 52
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 391
EP 395
DI 10.1086/422918
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300071
ER
PT J
AU Young, CH
Jorgensen, JK
Shirley, YL
Kauffmann, J
Huard, T
Lai, SP
Lee, CW
Crapsi, A
Bourke, TL
Dullemond, CP
Brooke, TY
Porras, A
Spiesman, W
Allen, LE
Blake, GA
Evans, NJ
Harvey, PM
Koerner, DW
Mundy, LG
Myers, PC
Padgett, DL
Sargent, AI
Stapelfeldt, KR
van Dishoeck, EF
Bertoldi, F
Chapman, N
Cieza, L
DeVries, CH
Ridge, NA
Wahhaj, Z
AF Young, CH
Jorgensen, JK
Shirley, YL
Kauffmann, J
Huard, T
Lai, SP
Lee, CW
Crapsi, A
Bourke, TL
Dullemond, CP
Brooke, TY
Porras, A
Spiesman, W
Allen, LE
Blake, GA
Evans, NJ
Harvey, PM
Koerner, DW
Mundy, LG
Myers, PC
Padgett, DL
Sargent, AI
Stapelfeldt, KR
van Dishoeck, EF
Bertoldi, F
Chapman, N
Cieza, L
DeVries, CH
Ridge, NA
Wahhaj, Z
TI A "starless'' core that isn't: Detection of a source in the L1014 dense
core with the Spitzer Space Telescope
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE infrared : stars; ISM : individual (L1014); stars : formation; stars :
low-mass, brown dwarfs
ID DARK CLOUDS; DISKS; MASS; SEQUENCE; EMISSION; PROGRAM; MODEL; STARS
AB We present observations of L1014, a dense core in the Cygnus region previously thought to be starless, but data from the Spitzer Space Telescope show the presence of an embedded source. We propose a model for this source that includes a cold core, heated by the interstellar radiation field, and a low-luminosity internal source. The low luminosity of the internal source suggests a substellar object. If L1014 is representative, other "starless'' cores may turn out to harbor central sources.
C1 Univ Texas, Austin, TX 78712 USA.
Leiden Observ, NL-2300 RA Leiden, Netherlands.
Natl Radio Astron Observ, Socorro, NM 87801 USA.
Max Planck Inst Radioastron, D-5300 Bonn, Germany.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Univ Maryland, Dept Astron, College Pk, MD 20742 USA.
Korea Astron Observ, Taejon 305348, South Korea.
Harvard Smithsonian Ctr Astrophys, Submillimeter Array Project, Hilo, HI 96720 USA.
Max Planck Inst Astrophys, D-85741 Garching, Germany.
CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA.
CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA.
No Arizona Univ, Dept Phys & Astron, Flagstaff, AZ 86011 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Young, CH (reprint author), Univ Texas, 1 Univ Stn,C-1400, Austin, TX 78712 USA.
RI Stapelfeldt, Karl/D-2721-2012;
OI Dullemond, Cornelis/0000-0002-7078-5910
NR 27
TC 129
Z9 129
U1 0
U2 3
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 396
EP 401
DI 10.1086/422818
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300072
ER
PT J
AU Roellig, TL
Van Cleve, JE
Sloan, GC
Wilson, JC
Saumon, D
Leggett, SK
Marley, MS
Cushing, MC
Kirkpatrick, JD
Mainzer, AK
Houck, JR
AF Roellig, TL
Van Cleve, JE
Sloan, GC
Wilson, JC
Saumon, D
Leggett, SK
Marley, MS
Cushing, MC
Kirkpatrick, JD
Mainzer, AK
Houck, JR
TI Spitzer Infrared Spectrograph (IRS) observations of M, L, and T dwarfs
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE infrared : stars; stars : low-mass, brown dwarfs
ID EXTRASOLAR GIANT PLANETS; BROWN DWARF; ATMOSPHERIC CHEMISTRY;
SPECTROSCOPIC SURVEY; MODEL ATMOSPHERES; SPACE-TELESCOPE; SKY SURVEY;
SPECTRA; STARS; CLOUDS
AB We present the first mid-infrared spectra of brown dwarfs, together with observations of a low-mass star. Our targets are the M3.5 dwarf GJ 1001A, the L8 dwarf DENIS-P J0255-4700, and the T1/T6 binary system epsilon Indi Ba/Bb. As expected, the mid-infrared spectral morphology of these objects changes rapidly with spectral class because of the changes in atmospheric chemistry resulting from their differing effective temperatures and atmospheric structures. By taking advantage of the unprecedented sensitivity of the Infrared Spectrograph on the Spitzer Space Telescope, we have detected the 7.8 mum methane and 10 mum ammonia bands for the first time in brown dwarf spectra.
C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Ball Aerosp & Technol Corp, Boulder, CO 80301 USA.
Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
Univ Virginia, Charlottesville, VA 22903 USA.
Los Alamos Natl Lab, Div Appl Phys, Los Alamos, NM 87545 USA.
Joint Astron Ctr, Hilo, HI 96720 USA.
NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA.
CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Roellig, TL (reprint author), NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA.
EM thomas.l.roellig@nasa.gov
RI Marley, Mark/I-4704-2013;
OI Leggett, Sandy/0000-0002-3681-2989
NR 37
TC 50
Z9 50
U1 0
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 418
EP 421
DI 10.1086/421978
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300076
ER
PT J
AU Meyer, MR
Hillenbrand, LA
Backman, DE
Beckwith, SVW
Bouwman, J
Brooke, TY
Carpenter, JM
Cohen, M
Gorti, U
Henning, T
Hines, DC
Hollenbach, D
Kim, JS
Lunine, J
Malhotra, R
Mamajek, EE
Metchev, S
Moro-Martin, A
Morris, P
Najita, J
Padgett, DL
Rodmann, J
Silverstone, MD
Soderblom, DR
Stauffer, JR
Stobie, EB
Strom, SE
Watson, DM
Weidenschilling, SJ
Wolf, S
Young, E
Engelbracht, CW
Gordon, KD
Misselt, K
Morrison, J
Muzerolle, J
Su, K
AF Meyer, MR
Hillenbrand, LA
Backman, DE
Beckwith, SVW
Bouwman, J
Brooke, TY
Carpenter, JM
Cohen, M
Gorti, U
Henning, T
Hines, DC
Hollenbach, D
Kim, JS
Lunine, J
Malhotra, R
Mamajek, EE
Metchev, S
Moro-Martin, A
Morris, P
Najita, J
Padgett, DL
Rodmann, J
Silverstone, MD
Soderblom, DR
Stauffer, JR
Stobie, EB
Strom, SE
Watson, DM
Weidenschilling, SJ
Wolf, S
Young, E
Engelbracht, CW
Gordon, KD
Misselt, K
Morrison, J
Muzerolle, J
Su, K
TI The formation and evolution of planetary systems: First results from a
Spitzer Legacy Science Program
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE circumstellar matter; infrared : stars; planetary systems :
protoplanetary disks
ID SOLAR-TYPE STARS; URSA-MAJOR GROUP; DUSTY DEBRIS; YOUNG STARS; DISK;
ABUNDANCES; LITHIUM; SAMPLE; AGE
AB We present 3-160 mum photometry obtained with the Infrared Array Camera (IRAC) and Multiband Imaging Photometer for Spitzer (MIPS) instruments for the first five targets from the Spitzer Space Telescope Legacy Science Program "Formation and Evolution of Planetary Systems'' and 4-35 mum spectrophotometry obtained with the Infrared Spectrograph (IRS) for two sources. We discuss in detail our observations of the debris disks surrounding HD 105 (G0 V, 30+/-10 Myr) and HD 150706 (G3 V, similar to700+/-300 Myr). For HD 105, possible interpretations include large bodies clearing the dust inside of 45 AU or a reservoir of gas capable of sculpting the dust distribution. The disk surrounding HD 150706 also exhibits evidence of a large inner hole in its dust distribution. Of the four survey targets without previously detected IR excess, spanning ages 30 Myr to 3 Gyr, the new detection of excess in just one system of intermediate age suggests a variety of initial conditions or divergent evolutionary paths for debris disk systems orbiting solar-type stars.
C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
CALTECH, Pasadena, CA 91125 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Space Telescope Sci Inst, Baltimore, MD 21218 USA.
Johns Hopkins Univ, Baltimore, MD 21218 USA.
Max Planck Inst Astron, D-69117 Heidelberg, Germany.
Univ Calif Berkeley, Berkeley, CA 94720 USA.
Space Sci Inst, Boulder, CO 80301 USA.
Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Natl Opt Astron Observ, Tucson, AZ 85719 USA.
Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA.
Planetary Sci Inst, Tucson, AZ 85719 USA.
RP Meyer, MR (reprint author), Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA.
OI Malhotra, Renu/0000-0002-1226-3305; Su, Kate/0000-0002-3532-5580
NR 36
TC 69
Z9 69
U1 0
U2 3
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 422
EP 427
DI 10.1086/423177
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300077
ER
PT J
AU Young, ET
Lada, CJ
Teixeira, P
Muzerolle, J
Muench, A
Stauffer, J
Beichman, CA
Rieke, GH
Hines, DC
Su, KYL
Engelbracht, CW
Gordon, KD
Misselt, K
Morrison, J
Stansberry, J
Kelly, D
AF Young, ET
Lada, CJ
Teixeira, P
Muzerolle, J
Muench, A
Stauffer, J
Beichman, CA
Rieke, GH
Hines, DC
Su, KYL
Engelbracht, CW
Gordon, KD
Misselt, K
Morrison, J
Stansberry, J
Kelly, D
TI Spitzer observations of NGC 2547: The disk population at 25 million
years
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE accretion, accretion disks; open clusters and associations : individual
(NGC 2547); stars : pre-main-sequence
ID LITHIUM DEPLETION; MASS STARS; PHOTOMETRY; SYSTEMS; CLUSTER; DWARFS
AB We present Spitzer observations of the young cluster NGC 2547, obtaining photometry at 3.6, 4.5, 5.8, 8.0, and 24 mum, reaching significantly fainter infrared sensitivities than previous studies. With these observations, we investigate the disk frequency in this cluster. A total of 3770, 2408, 1988, 1238, and 1123 sources were detected in the common region of the five respective bands. The detection limits were 14.9, 14.0, 13.5, 13.3, and 12.0 mag, respectively. The large majority of sources are associated with 2MASS objects. From this large ensemble, we utilize the criteria of Naylor et al. to identify 184 likely members of the cluster. The analyses in this paper are focused on these likely members. Of the 184 candidates, 162 were detected in at least one Infrared Array Camera (IRAC) band. These objects form a well-defined family in the J-K, K-[3.6] color-color diagram. There is no evidence for excess emission at 3.6 mum for cluster candidates with J-K<0.8, corresponding to spectral types earlier than late K. For later type stars, only 12 have evidence for a 3.6 μm excess. Hence, we derive a 3.6 μm emitting disk fraction of less than 7%. The lack of excess for the more massive stars may indicate a difference in the disk dissipation timescales for different mass stars. At 24 μm, 32 of the sources are detected. Most of them have photospheric K-[3.6] and K-[24] colors, but approximately a quarter show an excess at 24 μm. This observation may be evidence for cool disks with central holes.
C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Univ Lisbon, Fac Ciencias, Dept Fis, Lisbon, Portugal.
Univ Lisbon, Ctr Fis Nucl, Lisbon, Portugal.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Young, ET (reprint author), Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA.
RI Teixeira, Paula Stella/O-2289-2013;
OI Teixeira, Paula Stella/0000-0002-3665-5784; Muench,
August/0000-0003-0666-6367; Su, Kate/0000-0002-3532-5580
NR 16
TC 32
Z9 32
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 428
EP 432
DI 10.1086/422688
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300078
ER
PT J
AU Padgett, DL
Rebull, LM
Noriega-Crespo, A
Carey, SJ
Stapelfeldt, KR
Stauffer, JR
Burgdorf, MJ
Cole, DM
Fajardo-Acosta, SB
Frayer, DT
Helou, G
Hoard, DW
Karr, J
Latter, WB
Lowrance, PJ
O'Linger, J
Masci, F
Ramirez, S
Reach, WT
Rho, J
Stolovy, SR
Wachter, S
AF Padgett, DL
Rebull, LM
Noriega-Crespo, A
Carey, SJ
Stapelfeldt, KR
Stauffer, JR
Burgdorf, MJ
Cole, DM
Fajardo-Acosta, SB
Frayer, DT
Helou, G
Hoard, DW
Karr, J
Latter, WB
Lowrance, PJ
O'Linger, J
Masci, F
Ramirez, S
Reach, WT
Rho, J
Stolovy, SR
Wachter, S
TI An aggregate of young stellar disks in Lynds 1228 South
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE circumstellar matter; infrared : stars; ISM : clouds; ISM : individual
(LDN 1228); ISM : molecules; molecular clouds : general
ID MAIN-SEQUENCE STARS; CEPHEUS FLARE; ISOCAM OBSERVATIONS; OBJECT
CANDIDATES; MOLECULAR CLOUDS; SPACE-TELESCOPE; CO OBSERVATIONS;
EMISSION; DUST; REGION
AB Using the Multiband Imaging Photometer for Spitzer (MIPS) and Infrared Array Camera (IRAC) instruments on the Spitzer Space Telescope, we have investigated an aggregate of at least nine candidate bright young stellar objects in the southern region of the Lynds 1228 cloud in Cepheus. The spectral energy distributions (SEDs) encompass both infrared Class II and Class III types, and at least one object has no excess at wavelengths shorter than 24 mum. There are five known IRAS sources in the region. We find that the fluxes of these sources are generally overestimated by IRAS because of confusion, and one appears in both the IRAS Point Source and Faint Source Catalogs. This small group of young stellar objects provides a good example of the power of Spitzer to resolve star-forming regions confused in the IRAS catalogs. The SEDs of these sources illustrate that there can be a diversity of disk evolutionary states within a coeval stellar aggregate.
C1 CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Padgett, DL (reprint author), CALTECH, Spitzer Sci Ctr, MC 314-6,1200 E Calif Blvd, Pasadena, CA 91125 USA.
EM dlp@ipac.caltech.edu
RI Stapelfeldt, Karl/D-2721-2012;
OI Rebull, Luisa/0000-0001-6381-515X; Reach, William/0000-0001-8362-4094
NR 28
TC 10
Z9 10
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 433
EP 438
DI 10.1086/423132
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300079
ER
PT J
AU Uchida, KI
Calvet, N
Hartmann, L
Kemper, F
Forrest, WJ
Watson, DM
D'Alessio, P
Chen, CH
Furlan, E
Sargent, B
Brandl, BR
Herter, TL
Morris, P
Myers, PC
Najita, J
Sloan, GC
Barry, DJ
Green, J
Keller, LD
Hall, P
AF Uchida, KI
Calvet, N
Hartmann, L
Kemper, F
Forrest, WJ
Watson, DM
D'Alessio, P
Chen, CH
Furlan, E
Sargent, B
Brandl, BR
Herter, TL
Morris, P
Myers, PC
Najita, J
Sloan, GC
Barry, DJ
Green, J
Keller, LD
Hall, P
TI The state of protoplanetary material 10 million years after stellar
formation: Circumstellar disks in the TW Hydrae association
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE accretion, accretion disks; circumstellar matter; infrared : stars;
stars : formation; stars : pre-main-sequence
ID INFRARED SPECTROGRAPH IRS; SPITZER-SPACE-TELESCOPE; COMET HALE-BOPP;
TAURI STARS; CRYSTALLINE SILICATES; EMISSION; ACCRETION; SPECTRA;
ORIGIN; HERBIG
AB We have used the Spitzer Space Telescope Infrared Spectrograph to observe seven members of the TW Hya association, the nearest stellar association whose age (similar to10 Myr) is similar to the timescales thought to apply to planet formation and disk dissipation. Only two of the seven targets display infrared excess emission, indicating that substantial amounts of dust still exist closer to the stars than is characteristic of debris disks; however, in both objects we confirm an abrupt short-wavelength edge to the excess, as is seen in disks with cleared-out central regions. The mid-infrared excesses in the spectra of Hen 3-600 and TW Hya include crystalline silicate emission features, indicating that the grains have undergone significant thermal processing. We offer a detailed comparison between the spectra of TW Hya and Hen 3-600, and a model that corroborates the spectral shape and our previous understanding of the radial structure of these protoplanetary disks.
C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA.
Univ Nacl Autonoma Mexico, Ctr Radioastron & Astrofis, Morelia 58089, Michoacan, Mexico.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Sterrewacht Leiden, NL-2300 Leiden, Netherlands.
CALTECH, Spitzer Sci Ctr, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA.
Natl Opt Astron Observ, Tucson, AZ 85719 USA.
Ithaca Coll, Dept Phys, Ithaca, NY 14850 USA.
RP Uchida, KI (reprint author), Cornell Univ, Ctr Radiophys & Space Res, Space Sci Bldg, Ithaca, NY 14853 USA.
EM kuchida@isc.astro.cornell.edu
RI Kemper, Francisca/D-8688-2011;
OI Kemper, Francisca/0000-0003-2743-8240; Furlan, Elise/0000-0001-9800-6248
NR 36
TC 81
Z9 81
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 439
EP 442
DI 10.1086/422888
PG 4
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300080
ER
PT J
AU Forrest, WJ
Sargent, B
Furlan, E
D'Alessio, P
Calvet, N
Hartmann, L
Uchida, KI
Green, JD
Watson, DM
Chen, CH
Kemper, F
Keller, LD
Sloan, GC
Herter, TL
Brandl, BR
Houck, JR
Barry, DJ
Hall, P
Morris, PW
Najita, J
Myers, PC
AF Forrest, WJ
Sargent, B
Furlan, E
D'Alessio, P
Calvet, N
Hartmann, L
Uchida, KI
Green, JD
Watson, DM
Chen, CH
Kemper, F
Keller, LD
Sloan, GC
Herter, TL
Brandl, BR
Houck, JR
Barry, DJ
Hall, P
Morris, PW
Najita, J
Myers, PC
TI Mid-infrared spectroscopy of disks around classical T Tauri stars
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE circumstellar matter; infrared : stars; planetary systems :
protoplanetary disks; stars : individual (CoKu Tauri/4); stars :
pre-main-sequence; stars : variables : other
ID SPECTRAL ENERGY-DISTRIBUTIONS; MAIN-SEQUENCE EVOLUTION;
SPITZER-SPACE-TELESCOPE; AURIGA MOLECULAR CLOUD; YOUNG STELLAR OBJECTS;
ACCRETION DISKS; GRAIN-GROWTH; CIRCUMSTELLAR DISKS; MICRON SPECTROSCOPY;
DUST
AB We present the first Spitzer Space Telescope Infrared Spectrograph observations of the disks around classical T Tauri stars: spectra in the 5.2-30 mum range of six stars. The spectra are dominated by emission features from amorphous silicate dust, and a continuous component from 5 to 8 mum that in most cases comprises an excess above the photosphere throughout our spectral range. There is considerable variation in the silicate feature/continuum ratio, which implies variations of inclination, disk flaring, and stellar mass accretion rate. In most of our stars, structure in the silicate feature suggests the presence of a crystalline component. In one, CoKu Tau/4, no excess above the photosphere appears at wavelengths shortward of the silicate features, similar to 10 Myr old TW Hya, Hen 3-600, and HR 4796A. This indicates the optically thick inner disk is largely absent. The silicate emission features with peaks at 9.7 and 18 mum indicate small dust grains are present. The extremely low 10-20 mum color temperature of the dust excess, 135 K, indicates these grains are located more than 10 AU from the star. These features are suggestive of gravitational influence by planets or close stellar companions and grain growth in the region within 10 AU of the star, somewhat surprising for a star this young (1 Myr).
C1 Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA.
Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA.
Univ Nacl Autonoma Mexico, Ctr Radioastron & Astrofis, Morelia 58089, Michoacan, Mexico.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
Ithaca Coll, Dept Phys, Ithaca, NY 14850 USA.
Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Natl Opt Astron Observ, Tucson, AZ 85719 USA.
RP Forrest, WJ (reprint author), Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA.
EM forrest@pas.rochester.edu
RI Kemper, Francisca/D-8688-2011;
OI Kemper, Francisca/0000-0003-2743-8240; Furlan, Elise/0000-0001-9800-6248
NR 33
TC 99
Z9 99
U1 0
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 443
EP 447
DI 10.1086/423138
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300081
ER
PT J
AU Gorlova, N
Padgett, DL
Rieke, GH
Muzerolle, J
Morrison, JE
Gordon, KD
Engelbracht, CW
Hines, DC
Hinz, JC
Noriega-Crespo, A
Rebull, L
Stansberry, JA
Stapelfeldt, KR
Su, KYL
Young, ET
AF Gorlova, N
Padgett, DL
Rieke, GH
Muzerolle, J
Morrison, JE
Gordon, KD
Engelbracht, CW
Hines, DC
Hinz, JC
Noriega-Crespo, A
Rebull, L
Stansberry, JA
Stapelfeldt, KR
Su, KYL
Young, ET
TI New debris-disk candidates: 24 micron stellar excesses at 100 million
years
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE infrared : stars; open clusters and associations : individual (M47);
planetary systems : protoplanetary disks
ID UVBY-BETA-PHOTOMETRY; MAIN-SEQUENCE STARS; OPEN CLUSTER NGC-2422;
EVOLUTION; CATALOG; SAMPLE; COLORS; SEARCH
AB Sixty-three members of the 100 Myr old open cluster M47 (NGC 2422) have been detected at 24 mum with the Spitzer Space Telescope. The Be star V 378 Pup shows an excess both in the near-infrared and at 24 mum (K-[24]=2.4 mag), probably due to free-free emission from the gaseous envelope. Seven other early-type stars show smaller excesses, K-[24]=0.6-0.9. Among late-type stars, two show large excesses: P922, a K1 V star with K-[24]=1.08+/-0.11, and P1121, an F9 V star with K-[24]-3.72+/-0.02. P1121 is the first known main-sequence star showing an excess comparable to that of beta Pic, which may indicate the presence of an exceptionally massive debris disk. It is possible that a major planetesimal collision has occurred in this system, consistent with the few hundred Myr timescales estimated for the clearing of the solar system.
C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Space Sci Inst, Boulder, CO 80303 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Gorlova, N (reprint author), Univ Arizona, Steward Observ, 933 N Cherry Ave,Room N204, Tucson, AZ 85721 USA.
EM ngorlova@as.arizona.edu
RI Stapelfeldt, Karl/D-2721-2012;
OI Rebull, Luisa/0000-0001-6381-515X; Su, Kate/0000-0002-3532-5580
NR 38
TC 42
Z9 42
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 448
EP 452
DI 10.1086/422822
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300082
ER
PT J
AU Jura, M
Chen, CH
Furlan, E
Green, J
Sargent, B
Forrest, WJ
Watson, DM
Barry, DJ
Hall, P
Herter, TL
Houck, JR
Sloan, GC
Uchida, K
D'Alessio, P
Brandl, BR
Keller, LD
Kemper, F
Morris, P
Najita, J
Calvet, N
Hartmann, L
Myers, PC
AF Jura, M
Chen, CH
Furlan, E
Green, J
Sargent, B
Forrest, WJ
Watson, DM
Barry, DJ
Hall, P
Herter, TL
Houck, JR
Sloan, GC
Uchida, K
D'Alessio, P
Brandl, BR
Keller, LD
Kemper, F
Morris, P
Najita, J
Calvet, N
Hartmann, L
Myers, PC
TI Mid-infrared spectra of dust debris around main-sequence stars
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE circumstellar matter; infrared : stars
ID SPITZER-SPACE-TELESCOPE; LAMBDA-BOOTIS STARS; VEGA PHENOMENON; ASTEROID
BELT; DISKS; DISTRIBUTIONS; SIGNPOSTS; MIGRATION; CLUMPS; MODEL
AB We report spectra obtained with the Spitzer Space Telescope in the lambda=14-35 mum range of 19 nearby main-sequence stars with infrared excesses. The six stars with strong dust emission show no recognizable spectral features, suggesting that the bulk of the emitting particles have diameters larger than 10 mum. If the observed dust results from collisional grinding of larger solids, we infer minimum masses of the parent body population between 0.004 and 0.06 M(circle plus). We estimate grain production rates of similar to10(10) g s(-1) around lambda Boo and HR 1570; selective accretion of this matter may help explain their peculiar surface abundances. There appear to be inner truncations in the dust clouds at 48, 11, 52, and 54 AU around HR 333, HR 506, HR 1082, and HR 3927, respectively.
C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Cornell Univ, Dept Astron, Ithaca, NY 14853 USA.
Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA.
Univ Nacl Autonoma Mexico, Ctr Radioastron & Astrofis, Morelia 58089, Michoacan, Mexico.
Sterrewacht Leiden, NL-2300 RA Leiden, Netherlands.
Ithaca Coll, Dept Phys, Ithaca, NY 14850 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Natl Opt Astron Observ, Tucson, AZ 85726 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
RP Jura, M (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
RI Kemper, Francisca/D-8688-2011;
OI Kemper, Francisca/0000-0003-2743-8240; Furlan, Elise/0000-0001-9800-6248
NR 37
TC 40
Z9 40
U1 0
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 453
EP 457
DI 10.1086/422975
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300083
ER
PT J
AU Stapelfeldt, KR
Holmes, EK
Chen, C
Rieke, GH
Su, KYL
Hines, DC
Werner, MW
Beichman, CA
Jura, M
Padgett, DL
Stansberry, JA
Bendo, G
Cadien, J
Marengo, M
Thompson, T
Velusamy, T
Backus, C
Blaylock, M
Egami, E
Engelbracht, CW
Frayer, DT
Gordon, KD
Keene, J
Latter, WB
Megeath, T
Misselt, K
Morrison, JE
Muzerolle, J
Noriega-Crespo, A
Van Cleve, J
Young, ET
AF Stapelfeldt, KR
Holmes, EK
Chen, C
Rieke, GH
Su, KYL
Hines, DC
Werner, MW
Beichman, CA
Jura, M
Padgett, DL
Stansberry, JA
Bendo, G
Cadien, J
Marengo, M
Thompson, T
Velusamy, T
Backus, C
Blaylock, M
Egami, E
Engelbracht, CW
Frayer, DT
Gordon, KD
Keene, J
Latter, WB
Megeath, T
Misselt, K
Morrison, JE
Muzerolle, J
Noriega-Crespo, A
Van Cleve, J
Young, ET
TI First look at the Fomalhaut debris disk with the Spitzer Space Telescope
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE circumstellar matter; infrared : stars; planetary systems; stars :
individual (Fomalhaut)
ID NEARBY STARS; VEGA; PLANETS; MODELS
AB We present Spitzer Space Telescope early release observations of Fomalhaut, a nearby A-type star with dusty circumstellar debris. The disk is spatially resolved at 24, 70, and 160 mum using the Multiband Imaging Photometer for Spitzer (MIPS). While the disk orientation and outer radius are comparable to values measured in the submillimeter, the disk inner radius cannot be precisely defined: the central hole in the submillimeter ring is at least partially filled with emission from warm dust, seen in Spitzer Infrared Spectrograph (IRS) 17.5-34 mum spectra and MIPS 24 mum images. The disk surface brightness becomes increasingly asymmetric toward shorter wavelengths, with the south-southeast ansa always brighter than the north-northwest one. This asymmetry may reflect perturbations on the disk by an unseen interior planet.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
Space Sci Inst, Boulder, CO 80301 USA.
Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA.
Ball Aerosp Corp, Boulder, CO 80301 USA.
RP Stapelfeldt, KR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM krs@exoplanet.jpl.nasa.gov
RI Stapelfeldt, Karl/D-2721-2012;
OI Su, Kate/0000-0002-3532-5580
NR 30
TC 116
Z9 116
U1 0
U2 4
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 458
EP 462
DI 10.1086/423135
PG 5
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300084
ER
PT J
AU Stansberry, JA
Van Cleve, J
Reach, WT
Cruikshank, DP
Emery, JP
Fernandez, YR
Meadows, VS
Su, KYL
Misselt, K
Rieke, GH
Young, ET
Werner, MW
Engelbracht, CW
Gordon, KD
Hines, DC
Kelly, DM
Morrison, JE
Muzerolle, J
AF Stansberry, JA
Van Cleve, J
Reach, WT
Cruikshank, DP
Emery, JP
Fernandez, YR
Meadows, VS
Su, KYL
Misselt, K
Rieke, GH
Young, ET
Werner, MW
Engelbracht, CW
Gordon, KD
Hines, DC
Kelly, DM
Morrison, JE
Muzerolle, J
TI Spitzer observations of the dust coma and nucleus of
29P/Schwassmann-Wachmann 1
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE comets : general; comets : individual (29P/Schwassmann-Wachmann 1);
infrared : solar system; minor planets, asteroids
ID SCHWASSMANN-WACHMANN-1; ASTEROIDS; OUTBURST; B2
AB We obtained thermal images and spectra of comet and Centaur object 29P/Schwassmann-Wachmann 1 in late 2003 November. Images at 8, 24, and 70 mum reveal an extensive coma. At 24 mum the coma extends at least 8' from the nucleus and exhibits a single jet. The dust production rate is estimated as less than or similar to50 kg s(-1). The 24 to 70 mum color temperature of the coma is 160 K. The debris trail is also detected at 24 mum and has an optical depth of similar to(7+/-3)x10(-9). Thermal models fitted to photometry at 8, 24, and 70 mum indicate a nuclear radius of 27+/-5 km, larger than all previous size estimates, and a geometric albedo of 0.025+/-0.01, lower than any other Centaur object, but consistent with other comets. Analysis of the jet morphology indicates a rotation period in excess of 60 days. The spectra reveal features at 11.3 and 34 mum, which are tentatively identified as emission from olivine, including forsterite. This is the first identification of the minerology of the dust emitted by a Centaur object.
C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA.
Ball Aerosp & Technol Corp, Boulder, CO 80301 USA.
CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
SETI Inst, Mountain View, CA 94043 USA.
Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Stansberry, JA (reprint author), Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA.
EM stansber@as.arizona.edu
OI Su, Kate/0000-0002-3532-5580; Reach, William/0000-0001-8362-4094
NR 24
TC 57
Z9 57
U1 0
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 463
EP 468
DI 10.1086/422473
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300085
ER
PT J
AU Meadows, VS
Bhattacharya, B
Reach, WT
Grillmair, C
Noriega-Crespo, A
Ryan, EL
Tyler, SR
Rebull, LM
Giorgini, JD
Elliot, JL
AF Meadows, VS
Bhattacharya, B
Reach, WT
Grillmair, C
Noriega-Crespo, A
Ryan, EL
Tyler, SR
Rebull, LM
Giorgini, JD
Elliot, JL
TI The Spitzer First Look Survey - Ecliptic plane component: Asteroids and
zodiacal background
SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
LA English
DT Article
DE interplanetary medium; minor planets, asteroids
AB The Spitzer First Look Survey (FLS) provided an initial characterization of the infrared sky at Spitzer wavelengths and sensitivities. The ecliptic plane component (EPC) of the FLS concentrated on two 0.13 deg(2) fields at a solar elongation of 115degrees and ecliptic latitudes (beta) of 0degrees and +5degrees. The FLS-EPC explored the small asteroid counts at 8 and 24 mum, with a detection limit down to similar to0.08 and 0.8 mJy, respectively, and a completeness limit almost twice as deep as the 8 mum equivalent flux density of the previous deepest mid-IR survey. The FLS-EPC also provided initial characterization of the zodiacal light near the ecliptic plane. Fifteen known and 19 unknown asteroids were identified, and asteroids detected at both wavelengths displayed similar 8 to 24 mum flux ratios of similar to0.1. Comparing number counts for the beta=0degrees and +5degrees fields indicates a slower-than-anticipated drop-off in contrast to predicted scale heights, possibly due to the presence of higher inclination objects in the small population sampled by Spitzer. The measured zodiacal light background was found to be within 5% of Spitzer model predictions at 24 mum.
C1 CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA.
NASA, Astrobiol Inst, Washington, DC 20546 USA.
RP Meadows, VS (reprint author), CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA.
OI Rebull, Luisa/0000-0001-6381-515X; Reach, William/0000-0001-8362-4094
NR 7
TC 14
Z9 14
U1 0
U2 1
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0067-0049
J9 ASTROPHYS J SUPPL S
JI Astrophys. J. Suppl. Ser.
PD SEP
PY 2004
VL 154
IS 1
BP 469
EP 474
DI 10.1086/422414
PG 6
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850TB
UT WOS:000223634300086
ER
PT J
AU Hwang, EY
Pappas, D
Jeevarajan, AS
Anderson, MM
AF Hwang, EY
Pappas, D
Jeevarajan, AS
Anderson, MM
TI Evaluation of the paratrend multi-analyte sensor for potential
utilization in long-duration automated cell culture monitoring
SO BIOMEDICAL MICRODEVICES
LA English
DT Article
DE fiber-optic sensors; mammalian cell culture; pH sensor; pO(2) sensor;
blood gas analysis
ID SYSTEM
AB Background: Compact and automated sensors are desired for assessing the health of cell cultures in biotechnology experiments. While several single-analyte sensors exist to measure culture health, a multi-analyte sensor would simplify the cell culture system. One such multi-analyte sensor, the Paratrend 7 manufactured by Diametrics Medical, consists of three optical fibers for measuring pH, dissolved carbon dioxide (pCO(2)), dissolved oxygen (pO(2)), and a thermocouple to measure temperature. The sensor bundle was designed for intra-vascular measurements in clinical settings, and can be used in bioreactors operated both on the ground and in NASA's Space Shuttle and International Space Station (ISS) experiments.
Methods: A Paratrend 7 sensor was placed at the outlet of a bioreactor inoculated with BHK-21 (baby hamster kidney) cells. The pH, pCO(2), pO(2), and temperature data were transferred continuously to an external computer. Cell culture medium, manually extracted from the bioreactor through a sampling port, was also assayed using a bench top blood gas analyzer (BGA).
Results: Two Paratrend 7 sensors were used over a single cell culture experiment (64 days). When compared to the manually obtained BGA samples, the sensor had good agreement for pH, pCO(2), and pO(2) with bias (and precision) 0.005(0.024), 8.0 mmHg (4.4 mmHg), and 11 mmHg (17 mmHg), respectively for the first two sensors. A third Paratrend sensor (operated for 141 days) had similar agreement (0.02 +/- 0.15 for pH, - 4 +/- 8 mm Hg for pCO(2), and 24 +/- 18 mm Hg for pO(2)).
Conclusion: The resulting biases and precisions are comparable to Paratrend sensor clinical results. Although the pO(2) differences may be acceptable for clinically relevant measurement ranges, the O-2 sensor in this bundle may not be reliable enough for the ranges Of pO(2) in these cell culture studies without periodic calibration.
C1 NASA, Biol Syst Off, Johnson Space Ctr, Houston, TX 77058 USA.
Wyle Labs, Biotechnol Program, Houston, TX USA.
RP Jeevarajan, AS (reprint author), NASA, Biol Syst Off, Johnson Space Ctr, Mail Code SJ,2101 NASA Rd 1, Houston, TX 77058 USA.
EM antony.s.jeevarajan@nasa.gov
RI Pappas, Dimitri/F-7912-2013;
OI Pappas, Dimitri/0000-0002-5725-4816
NR 12
TC 7
Z9 7
U1 0
U2 9
PU KLUWER ACADEMIC PUBL
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 1387-2176
J9 BIOMED MICRODEVICES
JI Biomed. Microdevices
PD SEP
PY 2004
VL 6
IS 3
BP 241
EP 249
DI 10.1023/B:BMMD.0000042054.02940.b6
PG 9
WC Engineering, Biomedical; Nanoscience & Nanotechnology
SC Engineering; Science & Technology - Other Topics
GA 854OX
UT WOS:000223914300009
PM 15377834
ER
PT J
AU Kaur, I
Simons, ER
Castro, VA
Ott, CM
Pierson, DL
AF Kaur, I
Simons, ER
Castro, VA
Ott, CM
Pierson, DL
TI Changes in neutrophil functions in astronauts
SO BRAIN BEHAVIOR AND IMMUNITY
LA English
DT Article
DE stress; granulocytes; immune system; weightlessness; space flight
ID SPACE-FLIGHT; OXIDATIVE BURST; SPACEFLIGHT; RESPONSES; SUSPENSION; RAT;
REACTIVATION; LEUKOCYTES; EXERCISE; CELLS
AB Exploration class human spaceflight missions will require astronauts with robust immune systems. Innate immunity will be an essential element for the healthcare maintenance of astronauts during these lengthy expeditions. This study investigated neutrophil phagocytosis, oxidative burst, and degranulation of 25 astronauts after four space shuttle missions and in nine healthy control subjects. Space flight duration ranged from 5 to 11 days. Blood specimens were obtained 10 days before launch, immediately after landing, and 3 days after landing. The number of neutrophils increased by 85% at landing compared to preflight levels. The mean values for phagocytosis of Escherichia coli and oxidative burst capacity in neutrophils from astronauts on the 5-day mission were not significantly different from those observed in neutrophils from the control subjects. Before and after 9- to 11-day missions, however, phagocytosis and oxidative burst capacities were significantly lower than control mean values. No consistent changes in degranulation or expression of surface markers were observed before or after any of the space missions. This study indicates that neutrophil phagocytic and oxidative functions are affected by factors associated with space flight and this relationship may depend on mission duration. (C) 2004 Elsevier Inc. All rights reserved.
C1 NASA Johnson Space Ctr, Houston, TX 77058 USA.
Boston Univ, Sch Med, Dept Biochem, Boston, MA 02118 USA.
Enterprise Advisory Serv Inc, Houston, TX 77058 USA.
RP Pierson, DL (reprint author), NASA Johnson Space Ctr, Houston, TX 77058 USA.
EM dpierson@ems.jsc.nasa.gov
NR 24
TC 60
Z9 63
U1 1
U2 8
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0889-1591
J9 BRAIN BEHAV IMMUN
JI Brain Behav. Immun.
PD SEP
PY 2004
VL 18
IS 5
BP 443
EP 450
DI 10.1016/j.bbi.2003.10.005
PG 8
WC Immunology; Neurosciences
SC Immunology; Neurosciences & Neurology
GA 845AS
UT WOS:000223208600006
PM 15265537
ER
PT J
AU Duval, WMB
AF Duval, WMB
TI Flow field topology of transient mixing driven by buoyancy
SO CHAOS
LA English
DT Article
ID RAYLEIGH-TAYLOR INSTABILITY; LAGRANGIAN COHERENT STRUCTURES;
FLUX-CORRECTED TRANSPORT; STOKES-FLOW; CHAOS; MICROGRAVITY; ENVIRONMENT;
TURBULENCE; ALGORITHM; CRYSTALS
AB Transient mixing driven by buoyancy occurs through the birth of a symmetric Rayleigh-Taylor morphology (RTM) structure for large length scales. Beyond its critical bifurcation the RTM structure exhibits self-similarity and occurs on smaller and smaller length scales. The dynamics of the RTM structure, its nonlinear growth and internal collision, show that its genesis occurs from an explosive bifurcation which leads to the overlap of resonance regions in phase space. This event shows the coexistence of regular and chaotic regions in phase space which is corroborated with the existence of horseshoe maps. A measure of local chaos given by the topological entropy indicates that as the system evolves there is growth of uncertainty. Breakdown of the dissipative RTM structure occurs during the transition from explosive to catastrophic bifurcation; this event gives rise to annihilation of the separatrices which drives overlap of resonance regions. The global bifurcation of explosive and catastrophic events in phase space for the large length scale of the RTM structure serves as a template for which mixing occurs on smaller and smaller length scales.
C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
NR 75
TC 0
Z9 0
U1 0
U2 0
PU AMER INST PHYSICS
PI MELVILLE
PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA
SN 1054-1500
EI 1089-7682
J9 CHAOS
JI Chaos
PD SEP
PY 2004
VL 14
IS 3
BP 716
EP 738
DI 10.1063/1.1765031
PG 23
WC Mathematics, Applied; Physics, Mathematical
SC Mathematics; Physics
GA 854LL
UT WOS:000223904400023
PM 15446983
ER
PT J
AU Maiti, A
Ricca, A
AF Maiti, A
Ricca, A
TI Metal-nanotube interactions - binding energies and wetting properties
SO CHEMICAL PHYSICS LETTERS
LA English
DT Article
ID FIELD-EFFECT TRANSISTORS; WALLED CARBON NANOTUBES; OHMIC CONTACTS;
SINGLE; MOLECULES; PLATINUM
AB Recent experiments indicate wide variation of the quality of metal-nanotube contacts with the choice of metal. With An, Pt and Pd as examples, we present DFT results for the interaction of a metal atom, monolayer, multilayer and cluster with a graphene surface, a representative of wide-diameter carbon nanotubes. We also study nanotubes placed on flat metal surfaces. We discover interesting effects including, strong variations of binding energy as a function of metal configuration, and cross-section-deformation of nanotubes placed on Pt and Pd surfaces driven by sp(2) --> sp(3) transition of metal-adjacent C-atoms. The results provide an explanation for poorer Pt-contacts as compared to Pd. (C) 2004 Elsevier B.V. All rights reserved.
C1 Acceleys Inc, Mat Sci & Nanotechnol, San Diego, CA 92121 USA.
NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA.
RP Maiti, A (reprint author), Acceleys Inc, Mat Sci & Nanotechnol, 9685 Scranton Rd, San Diego, CA 92121 USA.
EM amaiti@accelrys.com
NR 21
TC 106
Z9 108
U1 1
U2 33
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0009-2614
EI 1873-4448
J9 CHEM PHYS LETT
JI Chem. Phys. Lett.
PD SEP 1
PY 2004
VL 395
IS 1-3
BP 7
EP 11
DI 10.1016/j.cplett.2004.07.024
PG 5
WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical
SC Chemistry; Physics
GA 851VT
UT WOS:000223714800002
ER
PT J
AU Goyal, VK
Johnson, ER
Davila, CG
AF Goyal, VK
Johnson, ER
Davila, CG
TI Irreversible constitutive law for modeling the delamination process
using interfacial surface discontinuities
SO COMPOSITE STRUCTURES
LA English
DT Article
DE delamination; cohesive-decohesive; constitutive law; decohesion elements
ID PROGRESSIVE DELAMINATION; ELEMENTS; SPECIMENS
AB An irreversible cohesive-decohesive constitutive law is postulated for interfacial surface discontinuities to predict initiation and progression of delamination. An exponential function is used for the constitutive law that naturally satisfies a multi-axial stress criterion for the onset of delamination and a mixed mode fracture criterion for the progression of delamination. The constitutive equations are made thermomechanically consistent by including a damage parameter to prevent the restoration of the previous cohesive state between the interfacial surfaces. To demonstrate the capability to predict delamination and the irreversibility capability of the constitutive law, steady-state delamination growth is simulated for quasi-static loading-unloading cycle of various fracture test specimens. The finite element results are in good agreement with either experimental data available in the literature or with linear elastic fracture mechanics analytical solutions which are valid for sufficiently long cracks. (C) 2003 Published by Elsevier Ltd.
C1 Virginia Polytech Inst & State Univ, Dept Aerosp & Ocean Engn, Blacksburg, VA 24061 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Goyal, VK (reprint author), POB 1528, El Segundo, CA 90245 USA.
EM vigoyal@vt.edu; erjohns4@vt.edu; c.g.davila@larc.nasa.gov
RI Davila, Carlos/D-8559-2011
NR 23
TC 55
Z9 55
U1 1
U2 7
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0263-8223
J9 COMPOS STRUCT
JI Compos. Struct.
PD SEP
PY 2004
VL 65
IS 3-4
BP 289
EP 305
DI 10.1016/j.comstruct.2003.11.005
PG 17
WC Materials Science, Composites
SC Materials Science
GA 844KW
UT WOS:000223158100004
ER
PT J
AU Thakoor, S
Morookian, JM
Chahl, J
Hine, B
Zornetzer, S
AF Thakoor, S
Morookian, JM
Chahl, J
Hine, B
Zornetzer, S
TI BEES: Exploring Mars with bioinspired technologies
SO COMPUTER
LA English
DT Article
ID EXPLORATION SYSTEMS
AB The bioinspired engineering of exploration systems (BEES) applies insects' biological sensory and flight control abilities to the design of real-time, autonomous, visual-navigation and -control systems for small, unmanned flying vehicles.
C1 CALTECH, Jet Prop Lab, BEES Mars Project, Pasadena, CA 91109 USA.
Australian Natl Univ, Canberra, ACT, Australia.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
EM sarita.thakoor@jpl.nasa.gov; Jobnmichael.Morookian@jpl.nasa.gov;
javaan.chahl@anu.edu.au; Bulter.P.Hine@nasa.gov;
szornetzer@mail.arc.nasa.gov
OI Chahl, Javaan/0000-0001-6496-0543
NR 23
TC 13
Z9 15
U1 0
U2 2
PU IEEE COMPUTER SOC
PI LOS ALAMITOS
PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA
SN 0018-9162
EI 1558-0814
J9 COMPUTER
JI Computer
PD SEP
PY 2004
VL 37
IS 9
BP 38
EP +
DI 10.1109/MC.2004.119
PG 11
WC Computer Science, Hardware & Architecture; Computer Science, Software
Engineering
SC Computer Science
GA 851IW
UT WOS:000223679800006
ER
PT J
AU Okong'o, N
Bellan, J
AF Okong'o, N
Bellan, J
TI Perturbation and initial Reynolds number effects on transition
attainment of supercritical, binary, temporal mixing layers
SO COMPUTERS & FLUIDS
LA English
DT Article
ID BOUNDARY-CONDITIONS; SHEAR-LAYER; SIMULATIONS; STABILITY; NITROGEN;
HEPTANE; FLOW; TURBULENCE; MIXTURES
AB Two- and three-dimensional (2D and 3D) numerical simulations are performed for a heptane/nitrogen (thermodynamically) supercritical mixing layer initially perturbed at different wavelengths, including the most unstable incompressible wavelength. Simulations are performed with spanwise (and streamwise, for 3D) perturbations available in the literature (for direct numerical simulations of turbulent flow) superimposed on the mean flow, and the domain length is four times the perturbation wavelength. The 2D simulations are undertaken to ascertain that perturbations having the shortest unstable wavelength obtained from a linear inviscid stability analysis are unstable for the viscous non-linear flow. For 3D layers, the purpose of the perturbations is to accelerate the growth of the layer in order to attain transitional Reynolds numbers, as well as to generate structures similar to those that have been observed in spatial mixing layers. The goal of the 3D simulations is to ascertain whether perturbing the mixing layer at different wavelengths, in contrast to the most unstable incompressible wavelength as had previously been done, will affect the transition to turbulence. In particular, we inquire whether perturbing the layer at smaller wavelengths, which requires a smaller domain, will reduce the computational time. It is found that transition can be obtained at different perturbation wavelengths, provided that they are longer than the shortest unstable wavelength as determined by the 2D linear inviscid stability analysis, and provided that the initial Reynolds number is proportionally increased as the wavelength is decreased. The transitional states thus obtained display different dynamic and mixture characteristics, and show strong departures from perfect gas, ideal mixtures. The smaller wavelength perturbations were found to have similar computational requirements for transition attainment. (C) 2003 Elsevier Ltd. All rights reserved.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Bellan, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 125-109, Pasadena, CA 91109 USA.
EM josette.bellan@jpl.nasa.gov
NR 25
TC 5
Z9 6
U1 0
U2 0
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0045-7930
J9 COMPUT FLUIDS
JI Comput. Fluids
PD SEP
PY 2004
VL 33
IS 8
BP 1023
EP 1046
DI 10.1016/j.compfluid.2003.10.001
PG 24
WC Computer Science, Interdisciplinary Applications; Mechanics
SC Computer Science; Mechanics
GA 811NI
UT WOS:000220778200002
ER
PT J
AU Calder, A
Dursi, J
Fryxell, B
Plewa, T
Weirs, G
Dupont, T
Robey, H
Kane, J
Remington, B
Timmes, F
Dimonte, G
Hayes, J
Zingale, M
Drake, P
Ricker, P
Stone, J
Olson, K
AF Calder, A
Dursi, J
Fryxell, B
Plewa, T
Weirs, G
Dupont, T
Robey, H
Kane, J
Remington, B
Timmes, F
Dimonte, G
Hayes, J
Zingale, M
Drake, P
Ricker, P
Stone, J
Olson, K
TI Validating astrophysical simulation codes
SO COMPUTING IN SCIENCE & ENGINEERING
LA English
DT Article
ID RAYLEIGH-TAYLOR; HYDRODYNAMICS; SUPERNOVA; DIFFUSION; FLAMES
C1 Univ Chicago, Chicago, IL 60637 USA.
Lawrence Livermore Natl Lab, ICF Program, Livermore, CA USA.
Los Alamos Natl Lab, Los Alamos, NM USA.
Univ Calif San Diego, San Diego, CA 92103 USA.
Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA.
Univ Michigan, Ann Arbor, MI 48109 USA.
Univ Illinois, Champaign, IL USA.
Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Calder, A (reprint author), Univ Chicago, Chicago, IL 60637 USA.
EM calder@flash.uchicago.edu; ljdursi@flash.uchicago.edu;
fryxell@flash.uchicago.edu; tomek@flash.uchicago.edu;
weirs@flash.uchicago.edu; t-dupont@uchicago.edu; robey1@llnl.gov;
jave@llnl.gov; remington2@llnl.gov; timmes@lanl.gov; dimonte@lani.gov;
jchayes@ucsd.edu; zingale@ucolick.org; pmricker@uiuc.edu;
zingale@ucolick.org; Kevin.Olson@gsfc.nasa.gov
RI Plewa, Tomasz/C-1470-2010; Calder, Alan/E-5348-2011;
OI Plewa, Tomasz/0000-0002-1762-2565; Zingale, Michael/0000-0001-8401-030X;
Dursi, Jonathan/0000-0002-4697-798X
NR 25
TC 2
Z9 2
U1 0
U2 1
PU IEEE COMPUTER SOC
PI LOS ALAMITOS
PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA
SN 1521-9615
J9 COMPUT SCI ENG
JI Comput. Sci. Eng.
PD SEP-OCT
PY 2004
VL 6
IS 5
BP 10
EP 20
DI 10.1109/MCSE.2004.44
PG 11
WC Computer Science, Interdisciplinary Applications
SC Computer Science
GA 848GY
UT WOS:000223456800005
ER
PT J
AU Kharuk, VI
Im, ST
Ranson, KJ
Naurzbaev, MM
AF Kharuk, VI
Im, ST
Ranson, KJ
Naurzbaev, MM
TI Temporal dynamics of larch in the forest-tundra ecotone
SO DOKLADY EARTH SCIENCES
LA English
DT Article
ID GROWTH
C1 Russian Acad Sci, Siberian Div, Sukachev Inst Forestry, Krasnoyarsk 660036, Russia.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Kharuk, VI (reprint author), Russian Acad Sci, Siberian Div, Sukachev Inst Forestry, Krasnoyarsk 660036, Russia.
EM kharuk@ksc.krasn.ru
RI Ranson, Kenneth/G-2446-2012; Im, Sergei/J-2736-2016
OI Ranson, Kenneth/0000-0003-3806-7270; Im, Sergei/0000-0002-5794-7938
NR 14
TC 6
Z9 6
U1 0
U2 2
PU INTERPERIODICA
PI BIRMINGHAM
PA PO BOX 1831, BIRMINGHAM, AL 35201-1831 USA
SN 1028-334X
J9 DOKL EARTH SCI
JI Dokl. Earth Sci.
PD SEP-OCT
PY 2004
VL 398
IS 7
BP 1020
EP 1023
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 862DR
UT WOS:000224470500031
ER
PT J
AU Bar-Ilan, A
Rein, G
Fernandez-Pello, AC
Torero, JL
Urban, DL
AF Bar-Ilan, A
Rein, G
Fernandez-Pello, AC
Torero, JL
Urban, DL
TI Forced forward smoldering experiments in microgravity
SO EXPERIMENTAL THERMAL AND FLUID SCIENCE
LA English
DT Article; Proceedings Paper
CT 3rd Mediterranean Combustion Symposium
CY JUN 08-13, 2003
CL Marrakech, MOROCCO
SP Combust Inst, Int Ctr Heat & Mass Transfer, Int Ctr Theoret Phys
DE smoldering combustion; microgravity; forward forced flow; buoyancy
effects
ID POLYURETHANE FOAM; FLOW
AB Results from two forward forced-flow smolder tests on polyurethane foam using air as oxidizer conducted aboard the NASA Space Shuttle (STS-105 and STS-108 missions) are presented in this work. The two tests provide the only presently available forward smolder data in microgravity. A complimentary series of ground-based tests were also conducted to determine, by comparison with the microgravity data, the effect of gravity on the forward smolder propagation. The objective of the study is to provide a better understanding of the controlling mechanisms of smolder for the purpose of control and prevention, both in normal- and microgravity. The data consists of temperature histories from thermocouples placed at various axial locations along the fuel sample centerline, and of permeability histories obtained from ultrasonic transducer pairs also located at various axial positions in the fuel sample. A comparison of the tests conducted in normal- and microgravity indicates that smolder propagation velocities are higher in microgravity than in normal gravity, and that there is a greater tendency for a transition to flame in microgravity than in normal gravity. This is due primarily to the reduced heat losses in the microgravity environment, leading to increased char oxidation. This observation is confirmed through a simplified one-dimensional model of the forward smolder propagation. This finding has important implications from the point of view of fire safety in a space-based environment, since smolder can often occur in the forward mode and potentially lead to a smolder-initiated fire. (C) 2004 Elsevier Inc. All rights reserved.
C1 Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA.
Univ Edinburgh, Sch Engn & Elect, Edinburgh EH9 3JN, Midlothian, Scotland.
NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Fernandez-Pello, AC (reprint author), Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA.
EM ferpello@me.berkeley.edu
OI Rein, Guillermo/0000-0001-7207-2685
NR 10
TC 26
Z9 31
U1 0
U2 8
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0894-1777
J9 EXP THERM FLUID SCI
JI Exp. Therm. Fluid Sci.
PD SEP
PY 2004
VL 28
IS 7
BP 743
EP 751
DI 10.1016/j.expthermalflusci.2003.12.012
PG 9
WC Thermodynamics; Engineering, Mechanical; Physics, Fluids & Plasmas
SC Thermodynamics; Engineering; Physics
GA 844HZ
UT WOS:000223150200012
ER
PT J
AU Camanho, PP
Davila, CG
Pinho, ST
AF Camanho, PP
Davila, CG
Pinho, ST
TI Fracture analysis of composite co-cured structural joints using
decohesion elements
SO FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
LA English
DT Article
DE co-cured joints; composite laminates; debonding
ID ENERGY-RELEASE RATES; LAMINATED COMPOSITES; INTERFACE ELEMENTS;
DELAMINATION; PREDICTION; CRACKS; ONSET
AB Delamination is one of the predominant forms of failure in laminated composite structures, especially when there is no reinforcement in the thickness direction. To develop composite structures that are more damage tolerant, it is necessary to understand how delamination develops, and how it can affect the residual performance. A number of factors such as residual thermal stresses, matrix-curing shrinkage and manufacturing defects affect how damage will grow in a composite structure. It is important to develop computationally efficient analysis methods that can account for all such factors. The objective of the current work is to apply a newly developed decohesion element to investigate the debond strength of skin-stiffener composite specimens. The process of initiation of delaminations and the propagation of delamination fronts is investigated. The numerical predictions are compared with published experimental results.
C1 Univ Porto, Fac Engn, Oporto, Portugal.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Camanho, PP (reprint author), Univ Porto, Fac Engn, Oporto, Portugal.
EM pcamanho@fe.up.pt
RI Camanho, Pedro /E-1666-2011; Pinho, Silvestre/B-4618-2012; Davila,
Carlos/D-8559-2011;
OI Camanho, Pedro/0000-0003-0363-5207
NR 26
TC 37
Z9 38
U1 1
U2 14
PU BLACKWELL PUBLISHING LTD
PI OXFORD
PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND
SN 8756-758X
J9 FATIGUE FRACT ENG M
JI Fatigue Fract. Eng. Mater. Struct.
PD SEP
PY 2004
VL 27
IS 9
BP 745
EP 757
DI 10.1111/j.1460-2695.2004.00695.x
PG 13
WC Engineering, Mechanical; Materials Science, Multidisciplinary
SC Engineering; Materials Science
GA 848MW
UT WOS:000223472800002
ER
PT J
AU Brat, G
Drusinsky, D
Giannakopoulou, D
Goldberg, A
Havelund, K
Lowry, M
Pasareanu, C
Venet, A
Visser, W
Washington, R
AF Brat, G
Drusinsky, D
Giannakopoulou, D
Goldberg, A
Havelund, K
Lowry, M
Pasareanu, C
Venet, A
Visser, W
Washington, R
TI Experimental evaluation of verification and validation tools on Martian
Rover software
SO FORMAL METHODS IN SYSTEM DESIGN
LA English
DT Article
DE model checking; testing; static analysis; runtime analysis; mars flight
software
AB We report on a study to determine the maturity of different verification and validation technologies (V&V) applied to a representative example of NASA flight software. The study consisted of a controlled experiment where three technologies ( static analysis, runtime analysis and model checking) were compared to traditional testing with respect to their ability to find seeded errors in a prototype Mars Rover controller. What makes this study unique is that it is the first ( to the best of our knowledge) controlled experiment to compare formal methods based tools to testing on a realistic industrial-size example, where the emphasis was on collecting as much data on the performance of the tools and the participants as possible. The paper includes a description of the Rover code that was analyzed, the tools used, as well as a detailed description of the experimental setup and the results. Due to the complexity of setting up the experiment, our results cannot be generalized, but we believe it can still serve as a valuable point of reference for future studies of this kind. It confirmed our belief that advanced tools can outperform testing when trying to locate concurrency errors. Furthermore, the results of the experiment inspired a novel framework for testing the next generation of the Rover.
C1 NASA, Ames Res Ctr, Kestrel Technol, Moffett Field, CA 94035 USA.
Time Rover, Cupertino, CA 95014 USA.
NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA.
RP Brat, G (reprint author), NASA, Ames Res Ctr, Kestrel Technol, Moffett Field, CA 94035 USA.
EM havelund@email.arc.nasa.gov; wvisser@email.arc.nasa.gov
NR 18
TC 21
Z9 21
U1 0
U2 0
PU KLUWER ACADEMIC PUBL
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0925-9856
J9 FORM METHOD SYST DES
JI Form. Methods Syst. Des.
PD SEP-NOV
PY 2004
VL 25
IS 2-3
BP 167
EP 198
DI 10.1023/B:FORM.0000040027.28662.a4
PG 32
WC Computer Science, Theory & Methods
SC Computer Science
GA 850WG
UT WOS:000223644500004
ER
PT J
AU Dixon, ET
Bogard, DD
Garrison, DH
Rubin, AE
AF Dixon, ET
Bogard, DD
Garrison, DH
Rubin, AE
TI Ar-39-Ar-40 evidence for early impact events on the LL parent body
SO GEOCHIMICA ET COSMOCHIMICA ACTA
LA English
DT Article
ID L-GROUP CHONDRITES; AR-AR AGES; THERMAL HISTORY; H-CHONDRITES; SHERGOTTY
ACHONDRITE; METEORITES; METAMORPHISM; FRAGMENTATION; AR-40-AR-39;
CHRONOLOGY
AB We determined Ar-39-Ar-40 ages of eight LL chondrites, and one igneous inclusion from an LL chondrite, with the object of understanding the thermal history of the LL-chondrite parent body. The meteorites in this study have a range of petrographic types from LL3.3 to LL6, and shock stages from SI to S4. These meteorites reveal a range of K-Ar ages from greater than or equal to3.66 to greater than or equal to4.50 Ga, and peak ages from greater than or equal to3.74 to greater than or equal to4.55 Ga. Significantly, three of the eight chondrites (LL4, 5, 6) have K-Ar ages of similar to4.27 Ga. One of these (MIL99301) preserves an Ar-39-Ar-40 age of 4.23 +/- 0.03 Ga from low-temperature extractions, and an older age of 4.52 +/- 0.08 Ga from the highest temperature extractions. In addition, an igneous-textured impact melt DOM85505,22 has a peak Ar-39-Ar-40 age of greater than or equal to4.27 Ga.
We interpret these results as evidence for impact events that occurred at about 4.27 Ga on the LL parent body that produced local impact melts, reset the Ar-39-Ar-40 ages of some meteorites, and exhumed (or interred) others, resulting in a range of cooling ages. The somewhat younger peak age of 3.74 Ga from GR095658 (LL3.3) suggests an additional impact event close to timing of impact-reset ages of some other ordinary chondrites between 3.6-3.8 Ga. The results from MIL99301 suggest that some apparently unshocked (S1) chondrites may have substantially reset Ar-39-Ar-40 ages. A previous petrographic investigation of MIL99301 suggested that reheating to temperatures less than or equal to type 4 petrographic conditions (600degreesC) caused fractures in olivine to anneal, resulting in a low apparent shock stage of S1 (unshocked). The Ar-39-Ar-40 age spectrum of MIL99301 is consistent with this interpretation. Older ages from high-T extractions may date an earlier impact event at 4.52 0.08 Ga, whereas younger ages from lower-T extractions date a later impact event at 4.23 0.03 Ga that may have caused annealing of feldspar and olivine. Copyright (C) 2004 Elsevier Ltd.
C1 NASA, Lyndon B Johnson Space Ctr, ARES, Code SR, Houston, TX 77058 USA.
Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA.
RP Los Alamos Natl Lab, Isotope & Nucl Chem CINC, POB 1663,MS J514, Los Alamos, NM 87545 USA.
EM edixon@lanl.gov
NR 52
TC 27
Z9 28
U1 0
U2 2
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0016-7037
EI 1872-9533
J9 GEOCHIM COSMOCHIM AC
JI Geochim. Cosmochim. Acta
PD SEP
PY 2004
VL 68
IS 18
BP 3779
EP 3790
DI 10.1016/j.gca.2004.02.023
PG 12
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 850SO
UT WOS:000223632900011
ER
PT J
AU Larsen, CF
Motyka, RJ
Freymueller, JT
Echelmeyer, KA
Ivins, ER
AF Larsen, CF
Motyka, RJ
Freymueller, JT
Echelmeyer, KA
Ivins, ER
TI Rapid uplift of southern Alaska caused by recent ice loss
SO GEOPHYSICAL JOURNAL INTERNATIONAL
LA English
DT Article
DE Alaskan tectonics; asthenosphere viscosity; Glacier Bay; postglacial
rebound; sea level change; uplift
ID SEA-LEVEL CHANGE; CRUSTAL DEFORMATION; MANTLE VISCOSITY;
BRITISH-COLUMBIA; ELIAS MOUNTAINS; LATE HOLOCENE; GLACIER BAY;
FLUCTUATIONS; CONSEQUENCES; LITHOSPHERE
AB Extreme uplift rates and sea level changes in southern Alaska have been documented by Global Positioning System (GPS) surveys, tide gauge measurements and studies of raised shorelines. The movements detected in a network of 45 GPS survey points describe a broad pattern of rapid regional uplift. The majority of the study area is uplifting at a rate faster than 10 mm yr(-1), with several sites uplifting more rapidly than 25 mm yr(-1). New tide gauge data presented here consist of repeat occupations of 18 temporary gauge sites. Sea level rates at these sites agree with similar measurements in southern Alaska taken similar to50 yr earlier, and also with the pattern of uplift derived from the GPS data. Raised shoreline studies at 14 sites document total sea level change, with a maximum change in sea level of -5.7 m found in upper Lynn Canal. The start of the ongoing uplift episode that raised these shorelines has been dated with dendrochronology and found to be coincident with the start of the collapse of the Glacier Bay Icefield, at ca. 1750 AD. The pattern of total sea level change is in general agreement with uplift-rate measurements, with greater sea level change found at the sites closest to the peak uplift rates in upper Glacier Bay. We use a viscoelastic earth model subjected to an ice load history built upon observations of glacial change to predict uplift rates at the tide gauge and GPS sites as well as the total uplift at the raised shoreline sites. Our modelling exercises are limited to an ice load model based on independent studies of the region's glacial history over the past 1.7 kyr, to evaluate whether the uplift observations can be explained by simple earth models subjected to this load history. Two-layer earth models, consisting of an elastic crust and a low-viscosity upper mantle half-space, can be adjusted to fit either the raised shoreline data or the combined GPS and tide gauge uplift-rate data, but cannot fit all the data with a single set of earth model parameters. However, all three data sets are consistent with an approximated three-layer earth model. The combined model is constrained by a total of 77 uplift measurements, which at the 95 per cent confidence level require a low-viscosity asthenosphere [eta(A)= (1.4 +/- 0.3) x 10(19) Pa s and thickness 110(-15)(+20) km] beneath a 50(-25)(+30) km thick elastic lithosphere and overlying an upper mantle half-space with a viscosity of 4 x 10(20) Pa s. This earth model achieves a low degree of misfit with the observations (reduced chi-square value of chi(nu)(2)= 2.5), suggesting that glacial isostatic rebound associated with post-Little Ice Age melting can entirely account for the rapid uplift of southern Alaska over the last similar to250 yr.
C1 Univ Alaska Fairbanks, Inst Geophys, Fairbanks, AK 99775 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Univ Alaska Fairbanks, Inst Geophys, 903 Koyukuk Dr, Fairbanks, AK 99775 USA.
EM chris@giseis.alaska.edu
NR 57
TC 33
Z9 33
U1 1
U2 8
PU OXFORD UNIV PRESS
PI OXFORD
PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND
SN 0956-540X
EI 1365-246X
J9 GEOPHYS J INT
JI Geophys. J. Int.
PD SEP
PY 2004
VL 158
IS 3
BP 1118
EP 1133
DI 10.1111/j.1365-246X.2004.02356.x
PG 16
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 848LY
UT WOS:000223470400026
ER
PT J
AU Fetzer, EJ
Teixeira, J
Olsen, ET
Fishbein, EF
AF Fetzer, EJ
Teixeira, J
Olsen, ET
Fishbein, EF
TI Satellite remote sounding of atmospheric boundary layer temperature
inversions over the subtropical eastern Pacific
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID MARINE STRATOCUMULUS; DATA PRODUCTS; AIRS/AMSU/HSB; CLOUDS
AB We describe atmospheric temperature inversions and height-resolved water vapor fields over the wintertime subtropical northeastern Pacific Ocean in observations by the satellite-borne Atmospheric Infrared Sounder ( AIRS) experiment. A comparison with model analyses shows good agreement in temperature. Water vapor comparisons with operational radiosondes at four sites in California and Hawaii during December 2002-January 2003 have low biases in the 1000-700 and 700-500 hPa layers. Maps of inversion frequency, and, water vapor at 1000-700 and 700-500 hPa over the subtropical northeast Pacific during 1-16 January 2003 - when high pressure and clear conditions prevail - show inversions occurring at a local minimum in water vapor at 1000 - 700 hPa. Water vapor at 700 - 500 hPa has a broad minimum extending from Baja California to Hawaii, with inversions found on its eastern half. These observations illustrate the potential of the AIRS data for describing a climatology of temperature and water vapor in subtropical oceanic regions.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
USN, Res Lab, Monterey, CA USA.
RP Fetzer, EJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 169-237, Pasadena, CA 91109 USA.
EM eric.j.fetzer@jpl.nasa.gov
NR 14
TC 30
Z9 30
U1 2
U2 8
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD SEP 1
PY 2004
VL 31
IS 17
AR L17102
DI 10.1029/2004GL020174
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 854FW
UT WOS:000223888100003
ER
PT J
AU Liao, MJ
Johnson, WN
AF Liao, MJ
Johnson, WN
TI Characterizing the effects of droplines on target acquisition
performance on a 3-D perspective display
SO HUMAN FACTORS
LA English
DT Article
ID FITTS LAW; 3-DIMENSIONAL DISPLAYS; MOVEMENTS; ELEVATION; TRACKING;
TASKS; HAND
AB The present study investigated the effects of droplines on target acquisition performance on a 3-D perspective display in which participants were required to move a cursor into a target cube as quickly as possible. Participants' performance and coordination strategies were characterized using both Fitts' law and acquisition patterns of the 3 viewer-centered target display dimensions (azimuth, elevation, and range). Participants' movement trajectories were recorded and used to determine movement times for acquisitions of the entire target and of each of its display dimensions. The goodness of fit of the data to a modified Fitts function varied widely among participants, and the presence of droplines did not have observable impacts on the goodness of fit. However, droplines helped participants navigate via straighter paths and particularly benefited range dimension acquisition. A general preference for visually overlapping the target with the cursor prior to capturing the target was found. Potential applications of this research include the design of interactive 3-D perspective displays in which fast and accurate selection and manipulation of content residing at multiple ranges may be a challenge.
C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
San Jose State Univ Fdn, Moffett Field, CA 94035 USA.
RP Liao, MJ (reprint author), NASA, Ames Res Ctr, Mail Stop 262-2, Moffett Field, CA 94035 USA.
EM mliao@mail.arc.nasa.gov
NR 39
TC 9
Z9 9
U1 0
U2 1
PU SAGE PUBLICATIONS INC
PI THOUSAND OAKS
PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA
SN 0018-7208
J9 HUM FACTORS
JI Hum. Factors
PD FAL
PY 2004
VL 46
IS 3
BP 476
EP 496
PG 21
WC Behavioral Sciences; Engineering, Industrial; Ergonomics; Psychology,
Applied; Psychology
SC Behavioral Sciences; Engineering; Psychology
GA 869JJ
UT WOS:000224978900009
PM 15573547
ER
PT J
AU Allen, CC
Probst, LW
Flood, BE
Longazo, TG
Schelble, RT
Westall, F
AF Allen, CC
Probst, LW
Flood, BE
Longazo, TG
Schelble, RT
Westall, F
TI Meridiani Planum hematite deposit and the search for evidence of life on
Mars - iron mineralization of microorganisms in rock varnish
SO ICARUS
LA English
DT Article
DE rock varnish; Mars; exobiology; hematite; Meridiani Planum; microfossil
ID DESERT VARNISH; MANGANESE-OXIDE; CRYSTALLINE HEMATITE; GUNFLINT
MICROBIOTA; MICROCOLONIAL FUNGI; FOSSIL BACTERIA; SONORAN DESERT;
HOT-SPRINGS; BIOFILMS; WATER
AB The extensive hematite deposit in Meridiani Planum was selected as the landing site for the Mars Exploration Rover Opportunity because the site may have been favorable to the preservation of evidence of possible prebiotic or biotic processes. One of the proposed mechanisms for formation of this deposit involves Surface weathering and coatings, exemplified on Earth by rock varnish. Microbial life, including microcolonial fungi and bacteria, is documented in rock varnish matrices from the southwestern United States and Australia. Limited evidence of this life is preserved as cells and cell molds mineralized by iron oxides and hydroxides, as well as by manganese oxides. Such mineralization of microbial cells has previously been demonstrated experimentally and documented in banded iron formations, hot spring deposits, and ferricrete soils. These types of deposits are examples of the four "water-rock interaction" scenarios proposed for formation of the hematite deposit on Mars. The instrument suite on Opportunity has the capability to distinguish among these proposed formation scenarios and, possibly, to detect traces that are suggestive of preserved martian microbiota. However, the confirmation of microfossils or preserved biosignatures will likely require the return of samples to terrestrial laboratories. Published by Elsevier Inc.
C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
Rice Univ, Houston, TX 77005 USA.
Univ So Calif, Los Angeles, CA 90089 USA.
Univ Arizona, Tucson, AZ 85721 USA.
Ctr Biophys Mol, F-45071 Orleans 2, France.
RP Allen, CC (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
EM carlton.c.allen@nasa.gov
NR 69
TC 15
Z9 16
U1 3
U2 11
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
EI 1090-2643
J9 ICARUS
JI Icarus
PD SEP
PY 2004
VL 171
IS 1
BP 20
EP 30
DI 10.1016/j.icarus.2004.04.015
PG 11
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 847PK
UT WOS:000223407200002
ER
PT J
AU Anderson, RC
Dohm, JM
Haldemann, AFC
Hare, TM
Baker, VR
AF Anderson, RC
Dohm, JM
Haldemann, AFC
Hare, TM
Baker, VR
TI Tectonic histories between Alba Patera and Syria Planum, Mars
SO ICARUS
LA English
DT Article
DE Mars; surface; tectonics; volcanism; geological processes; coronae;
Venus; mantle plume
ID NORTHERN PLAINS; PROVINCE; SYSTEMS; OCEANS
AB Syria Planum and Alba Patera are two of the most prominent features of magmatic-driven activity identified for the Tharsis region and perhaps for all of Mars. In this study, we have performed a Geographic Information System-based comparative investigation of their tectonic histories using published geologic map information and Mars Orbiter Laser Altimetry (MOLA) data. Our primary objective is to assess their evolutional histories by focusing on their extent of deformation in space and time through stratigraphic, paleotectonic, topographic, and geomorphologic analyses. Though there are similarities among the two prominent features, there are several distinct differences, including timing deformational extent, and tectonic intensity of formation. Whereas Alba Patera displays a major pulse of activity during the Late Hesperian/Early Amazonian, Syria Planum is a long-lived center that displays a more uniform distribution of simple graben densities ranging from the Noachian to the Amazonian, many of which occur at greater distances away from the primary center of activity. The histories of the two features presented here are representative of the complex, long-lived evolutional history of Tharsis. (C) 2004 Elsevier Inc. All rights reserved.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA.
US Geol Survey, Flagstaff, AZ 86001 USA.
RP Anderson, RC (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
EM robert.c.anderson@jpl.nasa.gov
RI Dohm, James/A-3831-2014;
OI Hare, Trent/0000-0001-8842-389X
NR 23
TC 25
Z9 25
U1 1
U2 3
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD SEP
PY 2004
VL 171
IS 1
BP 31
EP 38
DI 10.1016/j.icarus.2004.04.018
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 847PK
UT WOS:000223407200003
ER
PT J
AU Brasser, R
Innanen, KA
Connors, M
Veillet, C
Wiegert, P
Mikkola, S
Chodas, PW
AF Brasser, R
Innanen, KA
Connors, M
Veillet, C
Wiegert, P
Mikkola, S
Chodas, PW
TI Transient co-orbital asteroids
SO ICARUS
LA English
DT Article
DE asteroid; dynamics; earth
ID SOLAR-SYSTEM; EARTH; EVOLUTION; DYNAMICS
AB We analyze the orbital behavior of four new co-orbital NEOs and the Earth horseshoe object 2002 AA29. The new objects are 2001 CK32, a 3753 Cruithne-like co-orbital of Venus, 2001 GO2 and 2003 YN107, two objects with motion similar to 2002 AA29. 2001 CK32 is on a compound orbit. The asteroid reverses its path when the mean longitude difference is -50degrees. Its motion is chaotic. 2001 GO2 is an Earth HS orbiter with repeated transitions to the QS phase, the next occurring 200 years from now. The HS libration period is 190 years and the QS phases last 45 years. For 2002 AA29, our simulations permit us to find useful theoretical insights into the HS-QS transitions. Its orbit can be simulated with adequate accuracy for 4400 years into the future and 1483 years into the past. The new co-orbital 2003 YN107 is at present an Earth QS. It has entered this phase in 1997 and will leave it again in 2006, completing one QS cycle. Like 2002 AA29, it has frequent transitions between HS and QS. One HS cycle takes 133 years. (C) 2004 Elsevier Inc. All rights reserved.
C1 York Univ, Dept Phys & Astron, N York, ON M3J 1P3, Canada.
Athabasca Univ, Athabasca, AB T9S 3A3, Canada.
Univ Hawaii, Canada France Hawaii Telescope Corp, Kamuela, HI 96743 USA.
Univ Western Ontario, Dept Phys & Astron, London, ON N6A 5B8, Canada.
Univ Turku, Tuorla Observ, FI-21500 Piikkio, Finland.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Brasser, R (reprint author), York Univ, Dept Phys & Astron, 4700 Keele St, N York, ON M3J 1P3, Canada.
EM brasser_astro@yahoo.com
NR 23
TC 37
Z9 37
U1 1
U2 2
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD SEP
PY 2004
VL 171
IS 1
BP 102
EP 109
DI 10.1016/j.icarus.2004.04.019
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 847PK
UT WOS:000223407200008
ER
PT J
AU Wong, MH
Mahaffy, PR
Atreya, SK
Niemann, HB
Owen, TC
AF Wong, MH
Mahaffy, PR
Atreya, SK
Niemann, HB
Owen, TC
TI Updated Galileo probe mass spectrometer measurements of carbon, oxygen,
nitrogen, and sulfur on Jupiter
SO ICARUS
LA English
DT Article
DE Jupiter, atmosphere; atmospheres, composition; Galileo probe
ID CLOUD STRUCTURE; GIANT PLANETS; VOYAGER IRIS; ATMOSPHERIC COMPOSITION;
JOVIAN ATMOSPHERE; MOIST CONVECTION; ISOTOPIC RATIO; WATER ICE;
HOT-SPOT; SOLAR
AB The in situ measurements of the Galileo Probe Mass Spectrometer (GPMS) were expected to constrain the abundances of the cloud-forming condensible volatile gases: H2O, H2S, and NH3. However, since the probe entry site (PES) was an unusually dry meteorological system-a 5-mum hotspot-the measured condensible volatile abundances did not follow the canonical condensation-limited vertical profiles of equilibrium cloud condensation models (ECCMs) such as Weidenschilling and Lewis (1973, Icarus 20, 465-476). Instead, the mixing ratios of H2S and NH3 increased with depth, finally reaching well-mixed equilibration levels at pressures far greater than the lifting condensation levels, whereas the mixing ratio of H2O in the deep well-mixed atmosphere could not be measured. The deep NH3 mixing ratio (with respect to H-2) of (6.64 +/- 2.54) x 10(-4) from 8.9-11.7 bar GPMS data is consistent with the NH3 profile from probe-to-orbiter signal attenuation (Folkner et al., 1998, J. Geophys. Res. 103, 22847-22856), which had an equilibration level of about 8 bar. The GPMS deep atmosphere H2S mixing ratio of (8.9 +/- 2.1) x 10(-5) is the only measurement of Jupiter's sulfur abundance, with a PES equilibration level somewhere between 12 and 15.5 bar. The deepest water mixing ratio measurement is (4.9 +/- 1.6) x 10(-4) (corresponding to only about 30% of the solar abundance) at 17.6-20.9 bar, a value that is probably much smaller than Jupiter's bulk water abundance. The N-15/N-14 ratio in jovian NH3 was measured at (2.3 +/- 0.3) x 10(-3) and may provide the best estimate of the protosolar nitrogen isotopic ratio. The GPMS methane mixing ratio is (2.37 +/- 0.57) x 10(-3); although methane does not condense on Jupiter, we include its updated analysis in this report because like the condensible volatiles, it was presumably brought to Jupiter in icy planetesimals. Our detailed discussion of calibration and error analysis supplements previously reported GPMS measurements of condensible volatile mixing ratios (Niemann et al., 1998, J. Geophys. Res. 103, 22831-22846; Atreya et al., 1999, Planet. Space Sci. 47, 1243-1262; Atreya et al., 2003, Planet. Space Sci. 51, 105-112) and the nitrogen isotopic ratio (Owen et al., 2001b, Astrophys. J. Lett. 553, L77-L79). The approximately three times solar abundance of NH3 (along with CH4 and H2S) is consistent with enrichment of Jupiter's atmosphere by icy planetesimals formed at temperatures < 40 K (Owen et al., 1999, Nature 402 (6759), 269-270), but would imply that H2O should be at least 3 x solar as well. An alternate model, using clathrate hydrates to deliver the nitrogen component to Jupiter, predicts O/H greater than or equal to 9 x solar (Gautier et al., 2001, Astrophys. J. 550 (2), L227-L230). Finally we show that the measured condensible volatile vertical profiles in the PES are consistent with column-stretching or entraining downdraft scenarios only if the basic state (the pre-stretched column or the entrainment source region) is described by condensible volatile vertical profiles that are drier than those in the equilibrium cloud condensation models. This dryness is supported by numerous remote sensing results but seems to disagree with observations of widespread clouds on Jupiter at pressure levels predicted by equilibrium cloud condensation models for ammonia and H2S. (C) 2004 Elsevier Inc. All rights reserved.
C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA.
NASA, Goddard Space Flight Ctr, Atmospher Expt Branch, Code 915, Greenbelt, MD 20771 USA.
Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA.
Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA.
RP Wong, MH (reprint author), Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA.
EM mikewong@astro.berkeley.edu
RI Mahaffy, Paul/E-4609-2012
NR 70
TC 99
Z9 99
U1 0
U2 11
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD SEP
PY 2004
VL 171
IS 1
BP 153
EP 170
DI 10.1016/j.icarus.2004.04.010
PG 18
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 847PK
UT WOS:000223407200012
ER
PT J
AU Smyth, WH
Wong, MC
AF Smyth, WH
Wong, MC
TI Impact of electron chemistry on the structure and composition of Io's
atmosphere
SO ICARUS
LA English
DT Article
DE Io; satellites, atmospheres; atmospheres, structure; atmospheres,
composition; satellites of Jupiter
ID PLASMA; EMISSIONS; PHOTOCHEMISTRY; MORPHOLOGY; SULFUR; FLOW
AB Two-dimensional model calculations (altitude and solar zenith angle) are performed to investigate the impact of electron chemistry on the composition and structure of Io's atmosphere. The calculations are based upon the model of Wong and Smyth (2000, Icarus 146, 60-74) for Io's SO2 sublimation atmosphere with the addition of new electron chemistry, where the interactions of the electrons and neutrals are treated in a simple fashion. The model calculations are presented for to's atmosphere at western elongation (dusk ansa) for both a low-density case (subsolar temperature of 113 K) and a high-density case (subsolar temperature of 120 K). The impact of electron-neutral chemistry on the composition and structure of Io's atmosphere is confined primarily to an interaction layer. The penetration depth of the interaction layer is limited to high altitudes in the thicker dayside atmosphere but reaches the surface in the thinner dayside and/or nightside atmosphere at larger solar zenith angles. Within most of the thicker dayside atmosphere, the column density Of SO2 is not significantly altered by electrons, but in the interaction layer all number densities are significantly altered: SO2 is reduced, 0, SO, S, and O-2 are greatly enhanced, and 0, SO, and S become comparable to SO2 at high altitudes. For the thinner nightside atmosphere, the species number densities are dramatically altered: SO2 is drastically reduced to the least abundant species of the SO2 family, SO and O-2 are significantly reduced at all altitudes, and 0 and S are dramatically enhanced and become the dominant species at all altitudes except near the surface. The interaction layer also defines the location of the emission layer for neutrals excited by electron impact and hence determines the fraction of the total neutral column density that is visible in remote observation. Electron chemistry may also impact the ratio of the equatorial to polar SO2 column density deduced from Lyman-alpha images and the north-south alternating and System III longitude-dependent asymmetry observed in polar 0 and S emissions. (C) 2004 Elsevier Inc. All rights reserved.
C1 Atmospher & Environm Res Inc, Lexington, MA 02421 USA.
Jet Prop Lab, Pasadena, CA 91109 USA.
RP Smyth, WH (reprint author), Atmospher & Environm Res Inc, 131 Hartwell Ave, Lexington, MA 02421 USA.
EM smyth@aer.com
NR 25
TC 15
Z9 15
U1 0
U2 0
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD SEP
PY 2004
VL 171
IS 1
BP 171
EP 182
DI 10.1016/j.icarus.2004.04.001
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 847PK
UT WOS:000223407200013
ER
PT J
AU Dunn, DE
Molnar, LA
Niehof, JT
de Pater, I
Lissauer, JJ
AF Dunn, DE
Molnar, LA
Niehof, JT
de Pater, I
Lissauer, JJ
TI Microwave observations of Saturn's rings: anisotropy in directly
transmitted and scattered saturnian thermal emission
SO ICARUS
LA English
DT Article
DE Saturn, planetary rings; Saturn, atmosphere; Saturn, atmospheres,
dynamics; radiative transfer; radio observations
ID AZIMUTHAL BRIGHTNESS VARIATIONS; DENSE COLLISIONAL SYSTEMS; NUMERICAL
SIMULATIONS; LIGHT-SCATTERING; PLANETARY RINGS; SIZES
AB We present a new Very Large Array (VLA) image of Saturn, made from data taken in October 1998 at a wavelength of lambda3.6 cm. The moderate ring opening angle (B approximate to 15degrees) allows us to explore direct transmission of microwave photons through the A and C rings. We find a strong asymmetry of photons transmitted through the A ring, but not in the C ring, a new diagnostic of wake structure in the ring particles. We also find a weak asymmetry between east and west for the far side of the ansae. To facilitate quantitative comparison between dynamic models of the A ring and radio observations, we extend our Monte Carlo radiative transfer code (described in Dunn et al., 2002, Icarus 160, 132-160) to include idealized wakes. We show the idealized model can reproduce the properties of dynamic simulations in directly transmitted light. We examine the model behavior in directly transmitted and scattered light over a range of physical and geometric wake parameters. Finally, we present a wake model with a plausible set of physical parameters that quantitatively reproduces the observed intensity and asymmetry of the A ring both across the planet and in the ansae. (C) 2004 Elsevier Inc. All rights reserved.
C1 Sierra Coll, Dept Astron, Rocklin, CA 95677 USA.
Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA.
Calvin Coll, Dept Phys & Astron, Grand Rapids, MI 49546 USA.
NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA.
RP Dunn, DE (reprint author), Sierra Coll, Dept Astron, Rocklin, CA 95677 USA.
EM ddunn@sierracollege.edu
NR 30
TC 18
Z9 18
U1 0
U2 0
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD SEP
PY 2004
VL 171
IS 1
BP 183
EP 198
DI 10.1016/j.icarus.2004.04.008
PG 16
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 847PK
UT WOS:000223407200014
ER
PT J
AU Hicks, MD
Buratti, BJ
AF Hicks, MD
Buratti, BJ
TI The spectral variability of Triton from 1997-2000
SO ICARUS
LA English
DT Article
DE Triton; satellites of Neptune; satellite surfaces; photometry;
spectroscopy
ID SPACE-TELESCOPE; ATMOSPHERE; PHOTOMETRY; SPECTROGRAPH; VOYAGER-2;
STABILITY; STARS; TIME
AB We present the results of a three-year observational program of long-slit spectroscopy and UBVRI photometry of Triton. We find evidence for short-lived albedo variations at wavelengths less than 0.5 mum with the most notable reddening event measured in October 1997 and "normal" colors returning by May 1998. We report a possible variation in the relative 0.73/0.89 mum methane absorption band strengths, suggesting that the transport or denudation of this species may play a major role in the reddening events. (C) 2004 Published by Elsevier Inc.
C1 Jet Prop Lab, Pasadena, CA 91109 USA.
RP Hicks, MD (reprint author), Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM hicksm@galah.jpl.nasa.gov
NR 29
TC 19
Z9 19
U1 0
U2 0
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0019-1035
J9 ICARUS
JI Icarus
PD SEP
PY 2004
VL 171
IS 1
BP 210
EP 218
DI 10.1016/j.icarus.2004.02.012
PG 9
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 847PK
UT WOS:000223407200016
ER
PT J
AU Filman, RE
AF Filman, RE
TI Interface pains
SO IEEE INTERNET COMPUTING
LA English
DT Editorial Material
C1 NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA.
RP Filman, RE (reprint author), NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA.
EM filman@computer.org
NR 5
TC 0
Z9 0
U1 0
U2 0
PU IEEE COMPUTER SOC
PI LOS ALAMITOS
PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA
SN 1089-7801
J9 IEEE INTERNET COMPUT
JI IEEE Internet Comput.
PD SEP-OCT
PY 2004
VL 8
IS 5
BP 4
EP 6
DI 10.1109/MIC.2004.1273478
PG 3
WC Computer Science, Software Engineering
SC Computer Science
GA 852TD
UT WOS:000223778400001
ER
PT J
AU Yan, F
Xin, XB
Aslam, S
Zhao, YG
Franz, D
Zhao, JH
Weiner, M
AF Yan, F
Xin, XB
Aslam, S
Zhao, YG
Franz, D
Zhao, JH
Weiner, M
TI 4H-SiC UV photo detectors with large area and very high specific
detectivity
SO IEEE JOURNAL OF QUANTUM ELECTRONICS
LA English
DT Article
DE leakage current; photodiode; Schottky diodes; ultraviolet-detectors
ID AVALANCHE PHOTODIODES; SILICON-CARBIDE; CONTACTS; DEVICES
AB Pt/4H-SiC Schottky photodiodes have been fabricated with the device areas up to 1 cm(2). The I-V characteristics and photoresponse spectra have been measured and analyzed. For a 5 mm x 5 mm area device leakage current lower than 10(-15) A at zero bias and 1.2 x 10(-14) A at -1 V have been established. The quantum efficiency is over 30% from 240 to 320 nm. The specific detectivity, D*, has been calculated from the directly measured leakage current and quantum efficiency are shown to be higher than 10(15) cmHz(1/2)/W from 210 to 350 nm with a peak D* of 3.6 x 10(15) cmHz(1/2)/W at 300 nm.
C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Rutgers State Univ, Dept Elect & Comp Engn, Piscataway, NJ 08854 USA.
Keithley Instruments Inc, Cleveland, OH 44139 USA.
United Silicon Carbide Inc, New Brunswick, NJ 08901 USA.
RP Yan, F (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA.
EM fyna@pop500.gsfc.nasa.gov
RI Aslam, Shahid/D-1099-2012
NR 21
TC 64
Z9 67
U1 0
U2 21
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0018-9197
J9 IEEE J QUANTUM ELECT
JI IEEE J. Quantum Electron.
PD SEP
PY 2004
VL 40
IS 9
BP 1315
EP 1320
DI 10.1109/jqe.2004.833196
PG 6
WC Engineering, Electrical & Electronic; Optics; Physics, Applied
SC Engineering; Optics; Physics
GA 849ZD
UT WOS:000223579400019
ER
PT J
AU Villegas, FJ
Cwik, T
Rahmat-Samii, Y
Manteghi, M
AF Villegas, FJ
Cwik, T
Rahmat-Samii, Y
Manteghi, M
TI A parallel electromagnetic genetic-algorithm optimization (EGO)
application for patch antenna design
SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
LA English
DT Article
DE genetic algorithms; method of moments (MoM); microstrip antenna;
optimization; parallel computing
ID MICROSTRIP ANTENNAS; PLANAR ARRAYS; AMPLITUDE; REDUCTION; BANDWIDTH;
ELEMENTS; MOMENTS
AB In this paper, we describe an electromagnetic genetic algorithm (GA) optimization (EGO) application developed for the cluster supercomputing platform. A representative patch antenna design example for commercial wireless applications is detailed, which illustrates the versatility and applicability of the method. We show that EGO allows us to combine the accuracy of full-wave EM analysis with the robustness of GA optimization and the speed of a parallel computing algorithm. A representative patch antenna design case study is presented. We illustrate the use of EGO to design a dual-band antenna element for wireless communication (1.9 and 2.4 GHz) applications. The resulting antenna exhibits acceptable dual-band operation (i.e., better than - 10 dB return loss with 5.3 and 7% operating bandwidths at 1.9 and 2.4 GHz) while maintaining a cross-pol maximum field level at least 11 dB below the co-pol maximum.
C1 Aerosp Corp, El Segundo, CA 90245 USA.
Raytheon Elect Syst, El Segundo, CA 90245 USA.
CALTECH, Jet Prop Lab, High Performance Comp Grp, Pasadena, CA 91109 USA.
Univ Calif Los Angeles, Dept Elect Engn, Antenna Res & Measurement Lab, Los Angeles, CA 90095 USA.
RP Aerosp Corp, El Segundo, CA 90245 USA.
EM rahmat@ee.ucla.edu
RI Manteghi, Majid/A-1034-2009
OI Manteghi, Majid/0000-0002-1870-6082
NR 42
TC 68
Z9 69
U1 0
U2 4
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0018-926X
EI 1558-2221
J9 IEEE T ANTENN PROPAG
JI IEEE Trans. Antennas Propag.
PD SEP
PY 2004
VL 52
IS 9
BP 2424
EP 2435
DI 10.1109/TAP.2004.834071
PG 12
WC Engineering, Electrical & Electronic; Telecommunications
SC Engineering; Telecommunications
GA 854AB
UT WOS:000223871200024
ER
PT J
AU Turso, JA
Edwards, RM
AF Turso, JA
Edwards, RM
TI Kalman filter-based maximum a posteriori probability detection of
boiling water reactor stability
SO IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY
LA English
DT Article
DE dynamic response; fission reactors; Kalman filtering; nonlinear systems;
nuclear power generation control; stability
AB A diagnostic system has been developed to determine the global system stability characteristics of an operating boiling water reactor (BWR) using the average power range monitor (APRM) signal as an input. A Kalman filter-based monitor is used to identify the stability characteristics of a BWR using an "M-ary" hypothesis testing scheme. Each hypothesis, i.e., system model with slightly different stability characteristics, is represented by one of several Kalman filters operating in parallel. In addition to calculating the current estimate of the system's states, the monitor also produces the a posteriori probability that each filter calculates an accurate state vector estimate given the measurements. The best estimate of the system stability corresponds to the Kalman filter producing the maximum a posteriori probability (MAP). Results suggest that a significant time savings, when compared to stability diagnoses performed via a more established technique (autoregressive modeling) requiring 30 min to 1 h worth of data, can be obtained using the MAP BWR stability monitor. MAP monitor diagnoses are typically performed in 20 to 30 s. Thus, the MAP monitor represents a novel approach for the detection of BWR instabilities.
C1 NASA, Glenn Res Ctr, QSS Grp Inc, Cleveland, OH 44135 USA.
Penn State Univ, Dept Mech & Nucl Engn, University Pk, PA 16802 USA.
RP Turso, JA (reprint author), NASA, Glenn Res Ctr, QSS Grp Inc, Cleveland, OH 44135 USA.
EM James.A.Turso@grc.nasa.gov; e48@psu.edu
NR 12
TC 1
Z9 1
U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 1063-6536
J9 IEEE T CONTR SYST T
JI IEEE Trans. Control Syst. Technol.
PD SEP
PY 2004
VL 12
IS 5
BP 750
EP 756
DI 10.1109/tcst.2004.825148
PG 7
WC Automation & Control Systems; Engineering, Electrical & Electronic
SC Automation & Control Systems; Engineering
GA 849ZT
UT WOS:000223581100011
ER
PT J
AU Wilson, WJ
Yueh, SH
Dinardo, SJ
Li, FK
AF Wilson, WJ
Yueh, SH
Dinardo, SJ
Li, FK
TI High-stability L-band radiometer measurements of saltwater
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE microwave radiometry; microwave radiometry calibration; salinity; sea
surface; sea surface salinity (SSS)
AB L-band radiometer brightness temperature measurements of a saltwater pond were made as a function of salinity and temperature. A precision L-band radiometer with stability better than 0.1 K per day was used for these measurements. The L-band measurements are in good agreement with three dielectric constant models over a temperature range from 8 degreesC to 32 degreesC and a salinity range from 25-40 psu. Based on this experiment, these dielectric models will provide an excellent basis for the algorithm development and design of the future National Aeronautics and Space Administration Aquarius,satellite mission.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Wilson, WJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM william.j.wilson@jpl.nasa.gov; Simon.H.Yueh@jpl.nasa.gov;
Steven.J.Dinardo@jpl.nasa.gov; Fuk.K.Li@jpl.nasa.gov
NR 9
TC 12
Z9 12
U1 0
U2 1
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD SEP
PY 2004
VL 42
IS 9
BP 1829
EP 1835
DI 10.1109/TGRS.2004.833393
PG 7
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 854VM
UT WOS:000223931600004
ER
PT J
AU Kim, MJ
Skofronick-Jackson, GM
Weinman, JA
AF Kim, MJ
Skofronick-Jackson, GM
Weinman, JA
TI Intercomparison of millimeter-wave radiative transfer models
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE delta-scaling; Eddington second-order approximation; millimeter-wave;
Monte Carlo method; Neumann iterative method; radiative transfer model
ID PRECIPITATING CLOUDS; EDDINGTON APPROXIMATION; MICROWAVE RADIANCES;
HORIZONTALLY FINITE; HYDROMETEORS; SCATTERING; TRMM; GHZ; ICE
AB This study analyzes the performance at millimeter-wave frequencies of five radiative transfer models, i.e., the Eddington second-order approximation with and without delta-scaling, the Neumann iterative method with and without geometric series approximation, and the Monte Carlo method. Three winter time precipitation profiles are employed. The brightness temperatures calculated by the Monte Carlo method, which considers all scattering angles, are considered as benchmarks in this study. Brightness temperature differences generated by the other models and sources of those differences are examined. In addition, computation speeds of the radiative transfer calculations are also compared. Results show that the required number of quadrature angles to generate brightness temperatures consistent with the Monte Carlo method within 0.5 K varies between two and six. At least second to 15th orders of multiple scattering, depending on the significance of scattering, are required for the Neumann iterative method to represent accurately the inhomogeneous vertical structure of the scattering and absorbing components of precipitating clouds at millimeter-wave frequencies. The delta-scaling in the Eddington second-order approximation improves brightness temperatures significantly at nadir for cloud profiles that contain snow due to the correction for strong scattering, while it did not make any difference at 53degrees off-nadir. The computational time comparisons show that the Neumann iterative method generates accurate brightness temperatures with better computational efficiency than the Monte Carlo method for cloud profiles with weak scattering. However, it can consume computational time that is even greater than the Monte Carlo method for some millimeter-wave frequencies and cloud profiles with strong scattering. A geometric series approximation can improve computational efficiency of the Neumann iterative method for those profiles. In view of the ease of introducing scaled parameters into the Eddington second-order approximation, good computational time efficiency, and better than within 2 K accuracy when compared with the Monte Carlo method, we recommend its use for brightness temperature calculations at millimeter-waves in precipitating atmospheres.
C1 Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA.
NASA, Goddard Space Flight Ctr, Microwave Sensors Branch, Greenbelt, MD 20771 USA.
RP Kim, MJ (reprint author), Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA.
EM mjkim@atmos.washington.edu; Gail.S.Jackson@nasa.gov;
weinman@atmos.washington.edu
RI Skofronick-Jackson, Gail/D-5354-2012
NR 34
TC 10
Z9 11
U1 0
U2 2
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD SEP
PY 2004
VL 42
IS 9
BP 1882
EP 1890
DI 10.1109/TGRS.2004.833392
PG 9
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 854VM
UT WOS:000223931600009
ER
PT J
AU Slade, WH
Ressom, HW
Musavi, MT
Miller, RL
AF Slade, WH
Ressom, HW
Musavi, MT
Miller, RL
TI Inversion of ocean color observations using particle swarm optimization
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE computational intelligence; global optimization; remote sensing
inversion
ID INHERENT OPTICAL-PROPERTIES; DISSOLVED ORGANIC-MATTER; PHYTOPLANKTON
PIGMENTS; DEEP WATERS; MODEL; ABSORPTION; RETRIEVAL; COASTAL; SPECTRUM
AB Inversion of ocean color reflectance measurements can be cast as an optimization problem, Where particular parameters of a forward model are optimized in order to make the forward-modeled spectral, reflectance match the spectral reflectance of a given in situ sample. Here, a simulated ocean color dataset is used to test the capability of a recently introduced global optimization process, particle swarm optimization (PSO), in the retrieval of optical properties from ocean color. The performance of the PSO method was compared with the more common genetic algorithms (GA) in terms of model accuracy and computation time. The PSO method has been shown to outperform the GA in terms of model error. Of particular, importance to ocean color remote sensing is the speed advantage that PSO affords over GA.
C1 Univ Maine, Sch Marine Sci, Orono, ME 04469 USA.
Georgetown Univ, Vincent T Lombardi Canc Res Ctr, Biostat Unit, Dept Oncol, Washington, DC 20057 USA.
Univ Maine, Integrated Syst Lab, Dept Elect & Comp Engn, Orono, ME 04469 USA.
NASA, Earth Sci Applicat Directorate, Stennis Space Ctr, MS 39529 USA.
RP Univ Maine, Sch Marine Sci, Orono, ME 04469 USA.
EM wslade@ieee.org; hwr@georgetown.edu
NR 27
TC 28
Z9 28
U1 0
U2 6
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
SN 0196-2892
EI 1558-0644
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD SEP
PY 2004
VL 42
IS 9
BP 1915
EP 1923
DI 10.1109/TGRS.2004.833389
PG 9
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 854VM
UT WOS:000223931600012
ER
PT J
AU Pinheiro, ACT
Privette, JL
Mahoney, R
Tucker, CJ
AF Pinheiro, ACT
Privette, JL
Mahoney, R
Tucker, CJ
TI Directional effects in a daily AVHRR land surface temperature dataset
over Africa
SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
LA English
DT Article
DE angular effects; Advanced Very High Resolution Radiometer (AVHRR);
geometric optics; land surface temperature (LST); vegetation structure
ID HIGH-RESOLUTION RADIOMETER; CANOPY TEMPERATURE; PLANT CANOPIES; ORBIT
DRIFT; MODEL; ALGORITHM; CLASSIFICATION; SEA
AB Land surface temperature (LST) is a key indicator of the land surface state and can provide information on surface-atmosphere heat and mass fluxes, vegetation water stress, and soil moisture. Split-window algorithms have been used with National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) data to estimate instantaneous LST for nearly 20 years. However, the low accuracy of LST retrievals associated with intractable variability has often hindered its wide use. In this study, we developed a six-year daily (day and night) NOAA-14 AVHRR LST dataset over continental Africa. By combining vegetation structural data available in the literature and a geometric optics model, we estimated the fractions of sunlit and shaded endmembers observed by AVHRR for each pixel of each overpass. Although our simplistic approach requires many assumptions (e.g., only four endmember types per scene), we demonstrate through correlation that some of the AVHRR LST variability can be attributed to angular effects imposed by AVHRR orbit and sensor characteristics, in combination with vegetation structure. These angular effects lead to systematic LST biases, including "hot spot" effects when no shadows are observed. For example, a woodland case showed that LST measurements within the "hot-spot" geometry were about 9 K higher than those at other geometries. We describe the general patterns of these biases as a function of tree cover fraction, season, and satellite drift (time past launch). In general, effects are most pronounced over relatively sparse canopies (tree cover < 60 %), at wet season sun-view angle geometries (principal plane viewing) and early in the satellite lifetime. These results suggest that noise in LST time series may be strongly reduced for some locations and years, and that long-term LST climate data records should be normalized to a single sun-view geometry, if possible. However, much work remains before these can be accomplished.
C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA.
NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA.
Global Sci & Technol Inc, Greenbelt, MD 20771 USA.
RP Pinheiro, ACT (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA.
EM ana@hsb.gsfc.nasa.gov
RI Privette, Jeffrey/G-7807-2011
OI Privette, Jeffrey/0000-0001-8267-9894
NR 42
TC 55
Z9 57
U1 0
U2 5
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 0196-2892
J9 IEEE T GEOSCI REMOTE
JI IEEE Trans. Geosci. Remote Sensing
PD SEP
PY 2004
VL 42
IS 9
BP 1941
EP 1954
DI 10.1109/TGRS.2004.831886
PG 14
WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote
Sensing; Imaging Science & Photographic Technology
SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science
& Photographic Technology
GA 854VM
UT WOS:000223931600015
ER
PT J
AU Paulin, MG
Hoffman, LF
Assad, C
AF Paulin, MG
Hoffman, LF
Assad, C
TI Dynamics and the single spike
SO IEEE TRANSACTIONS ON NEURAL NETWORKS
LA English
DT Article
DE cerebellum; fractional calculus; state estimation; vestibular
ID FRACTIONAL-ORDER DYNAMICS; MAMMALIAN OLFACTORY-BULB; VESTIBULAR NEURONS;
AUDITORY SPACE; BRAIN; MAPS; NETWORK; PIGEON
AB Responses of vestibular primary afferent neurons to head rotation exhibit fractional-order dynamics. As a consequence, the head tends to be in a localized region of its state-space at spike times of a particular neuron during arbitrary head movements, and single spikes can be interpreted as state measurements. We are developing a model of neural computations underlying trajectory prediction and control tasks, based on this experimental observation. This is a step toward a formal neural calculus in which single spikes are modeled realistically as the operands of neural computation.
C1 Univ Otago, Zool & Neurosci Dept, Dunedin, New Zealand.
Univ Calif Los Angeles, Div Head & Neck Surg, Sch Med, Los Angeles, CA 90095 USA.
CALTECH, Jet Prop Lab, Bio Inspired Technol & Syst Grp, Pasadena, CA 91109 USA.
RP Paulin, MG (reprint author), Univ Otago, Zool & Neurosci Dept, Dunedin, New Zealand.
EM mike.paulin@stonebow.otago.ac.nz; lfh@ucla.edu; chris@brain.jpl.nasa.gov
NR 35
TC 12
Z9 13
U1 0
U2 0
PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
PI PISCATAWAY
PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA
SN 1045-9227
J9 IEEE T NEURAL NETWOR
JI IEEE Trans. Neural Netw.
PD SEP
PY 2004
VL 15
IS 5
BP 987
EP 994
DI 10.1109/TNN.2004.832814
PG 8
WC Computer Science, Artificial Intelligence; Computer Science, Hardware &
Architecture; Computer Science, Theory & Methods; Engineering,
Electrical & Electronic
SC Computer Science; Engineering
GA 853AN
UT WOS:000223798400005
PM 15484875
ER
PT J
AU Hasanyan, DJ
Librescu, L
Ambur, DR
AF Hasanyan, DJ
Librescu, L
Ambur, DR
TI A few results on the foundation of the theory and behavior of nonlinear
magnetoelastic plates carrying an electrical current
SO INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE
LA English
DT Article
DE nonlinear magnetoelastic plate; electrical current; instability; soft
and hard nonlinearities
ID FERROMAGNETIC ELASTIC SOLIDS; MAGNETIC-FIELD; VIBRATION
AB A fully nonlinear theory of electromagnetically conducting flat plates carrying an electric current and exposed to a magnetic field of an arbitrary orientation is developed. It is assumed that the electric current vector J is parallel to the plate mid-plane, and of arbitrary direction in the plane. It is also assumed that both the elastic and the electromagnetic media are homogeneous and isotropic. The geometrical nonlinearities are considered in the von-Karman sense, and the soft ferromagnetic material of the plate is assumed to feature negligible hysteretic losses.
Based on the electromagnetic equations (i.e. the ones by Faraday, Ampere, Ohm, Maxwell and Lorentz), and on elastokinetic field equations, the 3-D coupled problem is reduced to an equivalent 2-D one.
In this context, by using the presently developed theory, the problem of the loss of stability of plates carrying an electric current is investigated. The possibilities of enhancing their electric current carrying capacity are discussed. In the same context, the problem of the free vibration of flat plates as influenced by the electrical current and magnetic field is also addressed. (C) 2004 Elsevier Ltd. All rights reserved.
C1 Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Librescu, L (reprint author), Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA.
EM dhasanya@vt.edu; librescu@vt.edu; d.r.ambur@larc.nasa.gov
NR 27
TC 7
Z9 7
U1 0
U2 1
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0020-7225
J9 INT J ENG SCI
JI Int. J. Eng. Sci.
PD SEP
PY 2004
VL 42
IS 15-16
BP 1547
EP 1572
DI 10.1016/j.ijengsci.2004.04.003
PG 26
WC Engineering, Multidisciplinary
SC Engineering
GA 855OW
UT WOS:000223984600001
ER
PT J
AU Newman, JA
Piascik, RS
AF Newman, JA
Piascik, RS
TI Interactions of plasticity and oxide crack closure mechanisms near the
fatigue crack growth threshold
SO INTERNATIONAL JOURNAL OF FATIGUE
LA English
DT Article
DE fatigue crack growth threshold; oxide-induced crack closure;
plasticity-induced crack closure
ID BEHAVIOR; ENVIRONMENT
AB An advanced analytical model developed earlier has been utilized to predict interactions between plasticity and oxide crack closure mechanisms that influence near-threshold fatigue crack growth behavior. Near-threshold closure is complex because multiple closure mechanisms are likely, including plasticity and oxide-induced crack closure. A series of experiments has been performed to validate analytical results. Analytical and experimental results suggest that interactions between plasticity and oxide result in high closure levels near the fatigue crack growth threshold. At sufficiently low DeltaK, the combined effects of plasticity and oxide completely closes fatigue cracks resulting in high fatigue crack growth threshold values. Published by Elsevier Ltd.
C1 USA, Res Lab, Vehicle Technol Directorate, Hampton, VA 23681 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Newman, JA (reprint author), USA, Res Lab, Vehicle Technol Directorate, Mail Stop 188E, Hampton, VA 23681 USA.
EM j.a.newman@larc.nasa.gov
NR 14
TC 6
Z9 7
U1 1
U2 3
PU ELSEVIER SCI LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND
SN 0142-1123
J9 INT J FATIGUE
JI Int. J. Fatigue
PD SEP
PY 2004
VL 26
IS 9
BP 923
EP 927
DI 10.1016/j.ijfatigue.2004.02.001
PG 5
WC Engineering, Mechanical; Materials Science, Multidisciplinary
SC Engineering; Materials Science
GA 838US
UT WOS:000222739400002
ER
PT J
AU Wang, MH
AF Wang, MH
TI Extrapolation of the aerosol reflectance from the near-infrared to the
visible: the single-scattering epsilon vs multiple-scattering epsilon
method
SO INTERNATIONAL JOURNAL OF REMOTE SENSING
LA English
DT Article
ID ATMOSPHERIC CORRECTION ALGORITHM; WATER-LEAVING RADIANCE; OCEAN-COLOR
SENSORS; SPECTRAL REFLECTANCE; SURFACE-ROUGHNESS; SEAWIFS; SYSTEM;
INSTRUMENT; WHITECAPS; SCANNER
AB In the atmospheric correction algorithm for Sea-viewing Wide Field-of-view Sensor, the effects of the spectral variation of the aerosol radiance contributions at the two near-infrared (NIR) bands are estimated directly from sensor-measured radiance. The aerosol effects at the NIR are then extrapolated into the visible through a process of aerosol model selection from evaluation of the NIR single-scattering epsilon value, which is defined as the ratio of the single-scattering aerosol reflectance between two NIR bands. The aerosol radiance contribution at the visible wavelengths is then removed. In this paper, a slightly different approach in the aerosol model selection and extrapolation, i.e. using the NIR multiple-scattering epsilon instead of the single-scattering epsilon, is examined. The NIR multiple-scattering epsilon is the ratio of the aerosol multiple-scattering reflectance between two NIR wavelengths. Simulations show that, in general, both methods give comparable results. Statistically, more than 95% of cases in the retrieved ocean colour spectrum are within required accuracy for both methods. For clear atmosphere, however, the results of the atmospheric correction using the single-scattering epsilon method usually performed slightly better than the multiple-scattering epsilon method. On the other hand, for the large aerosol optical thickness the multiple-scattering epsilon method has slightly better retrievals for the Tropospheric aerosols. Some detailed analyses and discussions are provided to explain differences in these two approaches for extrapolating and retrieving the aerosol effects in the visible.
C1 Univ Maryland Baltimore Cty, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Wang, MH (reprint author), Univ Maryland Baltimore Cty, NASA, Goddard Space Flight Ctr, Code 970-2, Greenbelt, MD 20771 USA.
EM wang@simbios.gsfc.nasa.gov
RI Wang, Menghua/F-5631-2010
OI Wang, Menghua/0000-0001-7019-3125
NR 25
TC 10
Z9 10
U1 0
U2 1
PU TAYLOR & FRANCIS LTD
PI ABINGDON
PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND
SN 0143-1161
J9 INT J REMOTE SENS
JI Int. J. Remote Sens.
PD SEP
PY 2004
VL 25
IS 18
BP 3637
EP 3650
DI 10.1080/01431160310001619599
PG 14
WC Remote Sensing; Imaging Science & Photographic Technology
SC Remote Sensing; Imaging Science & Photographic Technology
GA 845LL
UT WOS:000223244100006
ER
PT J
AU Juarez, MD
Hajj, GA
Kursinski, ER
Kuang, D
Mannucci, AJ
Romans, LJ
AF Juarez, MD
Hajj, GA
Kursinski, ER
Kuang, D
Mannucci, AJ
Romans, LJ
TI Single frequency processing of atmospheric radio occultations
SO INTERNATIONAL JOURNAL OF REMOTE SENSING
LA English
DT Article
ID GLOBAL POSITIONING SYSTEM; EARTHS ATMOSPHERE; ORBIT
AB Tracking of the radio signals broadcast by the Global Positioning System (GPS) satellites as they are occulted from a GPS receiver by the Earth's atmosphere can provide high resolution vertical profiles of atmospheric refractivity, temperature and water vapour. Most implementations of this radio occultation technique use two GPS frequencies to correct for ionospheric effects. However, during most soundings, one of the frequencies is degraded by the introduction of the so-called Anti-Spoofing (AS) encryption mode. A retrieval method is discussed in this work for periods when only one of the two frequency signals has good quality. This method uses only the frequency with higher signal-to-noise ratio. We illustrate the quality of the atmospheric profiles obtained from such single frequency retrievals using GPS/MET data from the periods where the AS was turned off and the two frequencies were available. The results enable us to ensure the quality of a climate record of thousands of radio occultations collected by GPS/MET during the period with AS encryption, and the data processing of future missions with similar constraints, like IOX, can be performed.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Univ Arizona, Dept Atmospher Sci, Tucson, AZ USA.
RP Juarez, MD (reprint author), CALTECH, Jet Prop Lab, M-S 238-600,4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM mtj@jpl.nasa.gov
RI Mannucci, Anthony/A-1349-2007
OI Mannucci, Anthony/0000-0003-2391-8490
NR 17
TC 0
Z9 0
U1 0
U2 0
PU TAYLOR & FRANCIS LTD
PI ABINGDON
PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND
SN 0143-1161
J9 INT J REMOTE SENS
JI Int. J. Remote Sens.
PD SEP
PY 2004
VL 25
IS 18
BP 3731
EP 3744
DI 10.1080/0143116031000156800
PG 14
WC Remote Sensing; Imaging Science & Photographic Technology
SC Remote Sensing; Imaging Science & Photographic Technology
GA 845LL
UT WOS:000223244100011
ER
PT J
AU Jin, F
Balasubramaniam, R
Stebe, KJ
AF Jin, F
Balasubramaniam, R
Stebe, KJ
TI Surfactant adsorption to spherical particles: The intrinsic length scale
governing the shift from diffusion to kinetic-controlled mass transfer
SO JOURNAL OF ADHESION
LA English
DT Article
DE dynamic surface tension; microfluidics; capping agents
ID AIR-WATER-INTERFACE; AIR/WATER INTERFACE; DYNAMIC SURFACE; TENSION;
DESORPTION
AB When a drop or bubble of radius b is formed in surfactant solution, surfactant adsorbs, diffuses from solution, and desorbs to establish the equilibrium surface concentration. The transport coefficients for diffusion, adsorption, and desorption are fundamental parameters. However, the transport mechanisms that control the interface far from equilibrium are highly context dependent. Thus, no surfactant has universal "diffusion-controlled transport. Here we identify a new length scale, RD-K, that depends on surfactant physicochemistry, and which ranges from roughly 15 to 65 microns. For drops or bubbles with bRD-K, mass transfer is kinetically controlled. For bRD-K, mass transfer is diffusion controlled. Simulations of adsorption to quiescent spherical interfaces support the importance of RD-K in determining the controlling transport mechanism for surfactant solutions with concentrations below the critical micelle concentration (CMC). While the case of surfactant adsorbing to a bubble is discussed in detail, the arguments presented are quite general and should apply to adsorption of any solute to any spherical particle.
C1 Johns Hopkins Univ, Dept Chem & Biomol Engn, Baltimore, MD 21218 USA.
NASA, Glenn Res Ctr, Cleveland, OH USA.
Johns Hopkins Univ, Dept Mat Sci & Engn, Baltimore, MD 21218 USA.
Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA.
Johns Hopkins Univ, Dept Biomed Engn, Baltimore, MD USA.
RP Stebe, KJ (reprint author), Johns Hopkins Univ, Dept Chem & Biomol Engn, 3400 N Charles St, Baltimore, MD 21218 USA.
EM kjs@jhu.edu
NR 16
TC 31
Z9 31
U1 1
U2 28
PU TAYLOR & FRANCIS LTD
PI ABINGDON
PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND
SN 0021-8464
J9 J ADHESION
JI J. Adhes.
PD SEP
PY 2004
VL 80
IS 9
BP 773
EP 796
DI 10.1080/00218460490480770
PG 24
WC Engineering, Chemical; Materials Science, Multidisciplinary; Mechanics
SC Engineering; Materials Science; Mechanics
GA 851KI
UT WOS:000223683600001
ER
PT J
AU Darquenne, C
Prisk, GK
AF Darquenne, C
Prisk, GK
TI Aerosol deposition in the human respiratory tract breathing air and 80 :
20 heliox
SO JOURNAL OF AEROSOL MEDICINE-DEPOSITION CLEARANCE AND EFFECTS IN THE LUNG
LA English
DT Article
DE turbulent mixing; helium; particles
ID HELIUM OXYGEN MIXTURE; PARTICLE DEPOSITION; GAS-COMPOSITION; HUMAN-LUNG;
FLOW; HYPERGRAVITY; DIFFUSION; LAMINAR
AB Aerosol mixing resulting from turbulent flows is thought to be an important mechanism of deposition in the upper respiratory tract (URT). Since turbulence levels are a function of gas density, the use of a low density carrier gas would be expected to reduce deposition in the URT. We measured aerosol deposition in the respiratory tract of 8 healthy subjects using both air and heliox, a low density gas mixture containing 80% helium and 20% oxygen, as the carrier gas. The subjects breathed 0.5, 1, and 2 mum-diameter monodisperse polystyrene latex particles from a reservoir at a constant flow rate (similar to450 mL/sec) and tidal volume (similar to900 mL). Aerosol concentration and flow rate were measured at the mouth using a photometer and a pneumotachograph, respectively. Deposition was 17.0%, 20.3%, and 38.9% in air and 16.8%, 18.5%, and 36.9% in heliox for 0.5, 1, and 2 mum-diameter particles, respectively. There was a small but statistically significant decrease in deposition when using heliox compared to air for 1 and 2 mum-diameter particles (p < 0.05). While it could not be directly measured from these data, it is likely that when breathing heliox instead of air, deposition is reduced in the URT and increased in the small airways and alveoli.
C1 Univ Calif San Diego, Dept Med, NASA, Physiol Lab 0931, La Jolla, CA 92093 USA.
RP Darquenne, C (reprint author), Univ Calif San Diego, Dept Med, NASA, Physiol Lab 0931, 9500 Gilman Dr, La Jolla, CA 92093 USA.
EM cdarquenne@ucsd.edu
FU NIEHS NIH HHS [1 R01 ES11184-01A1, R01 ES011184]
NR 23
TC 26
Z9 26
U1 0
U2 3
PU MARY ANN LIEBERT INC
PI LARCHMONT
PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA
SN 0894-2684
J9 J AEROSOL MED
JI J. Aerosol Med.-Depos. Clear. Eff. Lung
PD FAL
PY 2004
VL 17
IS 3
BP 278
EP 285
DI 10.1089/jam.2004.17.278
PG 8
WC Public, Environmental & Occupational Health; Respiratory System
SC Public, Environmental & Occupational Health; Respiratory System
GA 858TR
UT WOS:000224215300009
PM 15625820
ER
PT J
AU Rossow, VJ
AF Rossow, VJ
TI Application of Vortex invariants to roll up of Vortex pairs
SO JOURNAL OF AIRCRAFT
LA English
DT Article
AB A method developed by Betz for the rolled-up structure of vortices shed by isolated wing tips is extended to vortex pairs (two vortical regions of opposite sign), which are shed by wings of finite span. The present analysis again uses the invariants for the two-dimensional time-dependent motion of vortex systems, but the extension made here to vortex pairs depends primarily on the invariant for kinetic energy. It is found that the total energy in the flowfield can be separated into a part that governs the structure of each vortical region and a part that governs the spanwise distance between the centroids of the vortical regions. As a consequence, the rules for the rolled-up structure of vortical regions are the same as the one derived by Betz. Because the analysis does not apply a constraint that forces the circular contours of constant circulation to coincide with streamline paths, the solution is labeled first order. A method that can be used to obtain second- and higher-order approximations is described. Application of the first-order method to the vortex wake of an elliptically loaded wing indicates that a first-order solution for vortex pairs is adequate for many engineering purposes. The method derived here for single vortex pairs also justifies the superposition of axially symmetric vortical cores to simulate complex vortex wakes.
C1 NASA, Ames Res Ctr, Aerosp Operat Modelling Off, Moffett Field, CA 94035 USA.
RP Rossow, VJ (reprint author), NASA, Ames Res Ctr, Aerosp Operat Modelling Off, Mail Stop N210-10, Moffett Field, CA 94035 USA.
NR 13
TC 2
Z9 2
U1 0
U2 0
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0021-8669
J9 J AIRCRAFT
JI J. Aircr.
PD SEP-OCT
PY 2004
VL 41
IS 5
BP 1098
EP 1105
DI 10.2514/1.1491
PG 8
WC Engineering, Aerospace
SC Engineering
GA 862EI
UT WOS:000224472600013
ER
PT J
AU Hajj, MR
Silva, WA
AF Hajj, MR
Silva, WA
TI Nonlinear mutter aspects of the flexible high-speed civil transport
semispan model
SO JOURNAL OF AIRCRAFT
LA English
DT Article; Proceedings Paper
CT AIAA/ASME/ASCE/AHS/ASC 44th Structures, Structural Dynamics and
Materials Conference
CY APR 07-10, 2003
CL Norfolk, VA
SP AIAA, ASME, ASCE, AHS, ASC
ID WAVE INTERACTIONS
AB The nonlinear aspects that lead to the flutter of the flexible semispan model of a high-speed civil transport wing configuration are analyzed. A hierarchy of spectral moments was used to determine the characteristics of the aerodynamic loading and structural strains and motions. The results show that the frequency of the bending motion of the wing varied significantly as the Mach number was increased between 0.90 and 0.97. Examination of the pressure coefficients in terms of mean value and fluctuations showed that the flow characteristics over the wing changed significantly around a Mach number of 0.97. A strong shock was identified near the trailing edge. Nonlinear analysis of the pressure fluctuations, under these conditions, showed nonlinear coupling involving low-frequency components at pressure locations where the mean value was at a local minimum. This shows that the aerodynamic forces acting on the model had nonlinearly coupled frequency components. The presented results show how nonlinear analysis tools can be used to identify nonlinear aspects of the flutter phenomenon, which are needed in the validation of nonlinear computational methodologies.
C1 Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA.
NASA, Langley Res Ctr, Aeroelastic Branch, Hampton, VA 23681 USA.
RP Hajj, MR (reprint author), Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, 0219 Norris Hall, Blacksburg, VA 24061 USA.
EM mhajj@vt.edu
RI Hajj, Muhammad/A-1176-2010
NR 5
TC 8
Z9 8
U1 0
U2 0
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0021-8669
J9 J AIRCRAFT
JI J. Aircr.
PD SEP-OCT
PY 2004
VL 41
IS 5
BP 1202
EP 1208
DI 10.2514/1.2225
PG 7
WC Engineering, Aerospace
SC Engineering
GA 862EI
UT WOS:000224472600026
ER
PT J
AU Shepherd, JM
Taylor, OO
Garza, C
AF Shepherd, JM
Taylor, OO
Garza, C
TI A dynamic GIS-multicriteria technique for siting the NASA-Clark Atlanta
urban rain gauge network
SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY
LA English
DT Article
ID ST-LOUIS; HEAT-ISLAND; PRECIPITATION; TRMM; PATTERNS; MODEL; AREAS; LAND
AB Because Atlanta, Georgia, is a model of rapid transition from forest/agriculture land use to urbanization, NASA and other agencies have initiated programs to identify and understand how urban heat islands (UHIs) impact the environment in terms of land use, air quality, health, climate, and other factors. Atlanta's UHI may also impact the regional water cycle by inadvertent forcing of precipitating cloud systems. Yet, a focused assessment of the role of urban-induced rainfall in Atlanta has not been a primary focus of past efforts. Several observational and climatological studies have theorized that UHIs can have a significant influence on mesoscale circulations and resulting convection. Using spaceborne rain radar and a limited network of irregularly spaced, ground-based rain gauges, evidence that the Atlanta and Houston, Dallas, and San Antonio, Texas, urban areas may modify cloud and precipitation development was recently found.
To validate these recent satellite-based findings, it was determined that a higher density of rainfall gauges would be required for future work. The NASA-sponsored Study of Precipitation Anomalies from Widespread Urban Landuse ( SPRAWL) seeks to further address the impact of urban Atlanta on precipitation variability by implementing a dense rain gauge network to validate spaceborne rainfall estimates. To optimize gauge location to a given set of criteria, a geographical information system (GIS) aided by a spatial decision support system (DSS) has been developed. A multicriteria decision analysis (MCDA) technique was developed to locate optimal sites in accordance to the guidelines defined by the World Meteorological Organization (WMO). A multicriteria analysis model for the optimization of prospective sites was applied to identify prime locations for the tipping-bucket rain gauges. The MCDA design required development of a spatial model by applying a series of linear programming methods, with the aid of spatial analytical techniques, in order to identify land sites that meet a particular set of criteria.
C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
Clark Atlanta Univ, Earth Syst Sci Program, Atlanta, GA 30314 USA.
RP Shepherd, JM (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
EM shepherd@agnes.gsfc.nasa.gov
NR 44
TC 11
Z9 12
U1 2
U2 10
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0739-0572
J9 J ATMOS OCEAN TECH
JI J. Atmos. Ocean. Technol.
PD SEP
PY 2004
VL 21
IS 9
BP 1346
EP 1363
DI 10.1175/1520-0426(2004)021<1346:ADGTFS>2.0.CO;2
PG 18
WC Engineering, Ocean; Meteorology & Atmospheric Sciences
SC Engineering; Meteorology & Atmospheric Sciences
GA 851KX
UT WOS:000223685100003
ER
PT J
AU Li, LH
Heymsfield, GM
Racette, PE
Tian, L
Zenker, E
AF Li, LH
Heymsfield, GM
Racette, PE
Tian, L
Zenker, E
TI A 94-GHz cloud radar system on a NASA high-altitude ER-2 aircraft
SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY
LA English
DT Article
ID CIRRUS CLOUDS; AIRBORNE; PRECIPITATION; REFLECTIVITY; ATTENUATION; GHZ
AB The 94-GHz ( W band) Cloud Radar System (CRS) has been developed and flown on a NASA ER-2 high-altitude ( 20 km) aircraft. The CRS is a fully coherent, polarimetric Doppler radar that is capable of detecting clouds and precipitation from the surface up to the aircraft altitude in the lower stratosphere. The radar is especially well suited for cirrus cloud studies because of its high sensitivity and fine spatial resolution. This paper describes the CRS motivation, instrument design, specifications, calibration, and preliminary data from NASA's Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment ( CRYSTAL - FACE) field campaign. The unique combination of CRS with other sensors on the ER-2 provides an unprecedented opportunity to study cloud radiative effects on the global energy budget. CRS observations are being used to improve our knowledge of atmospheric scattering and attenuation characteristics at 94 GHz, and to provide datasets for algorithm implementation and validation for the upcoming NASA CloudSat mission that will use a 94-GHz spaceborne cloud radar to provide the first direct global survey of the vertical structure of cloud systems.
C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
Sci Syst & Applicat Inc, Greenbelt, MD USA.
RP Li, LH (reprint author), NASA, Goddard Space Flight Ctr, Code 912,Bldg 33,Room C426, Greenbelt, MD 20771 USA.
EM lihua@agnes.gsfc.nasa.gov
NR 30
TC 44
Z9 46
U1 1
U2 4
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0739-0572
EI 1520-0426
J9 J ATMOS OCEAN TECH
JI J. Atmos. Ocean. Technol.
PD SEP
PY 2004
VL 21
IS 9
BP 1378
EP 1388
DI 10.1175/1520-0426(2004)021<1378:AGCRSO>2.0.CO;2
PG 11
WC Engineering, Ocean; Meteorology & Atmospheric Sciences
SC Engineering; Meteorology & Atmospheric Sciences
GA 851KX
UT WOS:000223685100005
ER
PT J
AU Huff, JL
Lynch, MP
Nettikadan, S
Johnson, JC
Vengasandra, S
Henderson, E
AF Huff, JL
Lynch, MP
Nettikadan, S
Johnson, JC
Vengasandra, S
Henderson, E
TI Label-free protein and pathogen detection using the atomic force
microscope
SO JOURNAL OF BIOMOLECULAR SCREENING
LA English
DT Article
DE atomic force microscope; nanoarray; virus detection; label-free
detection
ID SCANNING PROBE MICROSCOPY; ELECTRON-MICROSCOPY; ADHESION FORCES;
REAL-TIME; DIAGNOSIS; VIROLOGY; VIRUSES; ARRAYS
AB The atomic force microscope (AFM) uses a sharp micron-scale tip to scan and amplify surface features, providing exceptionally detailed topographical information with magnification on the order of x 10(6). This instrument is used extensively for quality control in the computer and semiconductor industries and is becoming a progressively more important tool in the biological sciences. Advantages of the AFM for biological application include the ability to obtain information in a direct, label-free manner and the ability to image in solution, providing real-time data acquisition under physiologically relevant conditions. A novel application of the AFM currently under development combines its surface profiling capabilities with fixed immunocapture using antibodies immobilized in a nanoarray formal. This provides a distinctive platform for direct, label-free detection and characterization of viral particles and other pathogens.
C1 Bioforce Nanosci Inc, Ames, IA 50014 USA.
Des Moines Univ, Dept Microbiol, Des Moines, IA USA.
Iowa State Univ, Dept GDCB, Ames, IA USA.
Univ Space Res Assoc, Lyndon B Johnson Space Ctr, Houston, TX USA.
RP Lynch, MP (reprint author), Bioforce Nanosci Inc, 2901 S Loop Dr,Suite 3400, Ames, IA 50014 USA.
EM mlynch@bioforcenano.com
NR 39
TC 21
Z9 24
U1 2
U2 6
PU SAGE PUBLICATIONS INC
PI THOUSAND OAKS
PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA
SN 1087-0571
J9 J BIOMOL SCREEN
JI J. Biomol. Screen
PD SEP
PY 2004
VL 9
IS 6
BP 491
EP 497
DI 10.1177/1087057104268803
PG 7
WC Biochemical Research Methods; Biotechnology & Applied Microbiology;
Chemistry, Analytical
SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology;
Chemistry
GA 853PB
UT WOS:000223838400004
PM 15452335
ER
PT J
AU Gu, GJ
Adler, RF
AF Gu, GJ
Adler, RF
TI Seasonal evolution and variability associated with the West African
monsoon system
SO JOURNAL OF CLIMATE
LA English
DT Article
ID SEA-SURFACE TEMPERATURE; EQUATORIAL ATLANTIC-OCEAN; EASTERLY WAVES;
RAINFALL VARIABILITY; INTRASEASONAL VARIABILITY; ATMOSPHERIC
CIRCULATION; NORTHERN SUMMER; ANNUAL CYCLE; PART II; DYNAMICS
AB In this study, the seasonal variations in surface rainfall and associated large-scale processes in the tropical eastern Atlantic and West African region are investigated. The 6-yr (1998-2003) high-quality Tropical Rainfall Measuring Mission ( TRMM) rainfall, sea surface temperature (SST), water vapor, and cloud liquid water observations are applied along with the NCEP-NCAR reanalysis wind components and a 4-yr (2000-2003) Quick Scatterometer (Quik SCAT) satellite-observed surface wind product.
Major mean rainfall over West Africa tends to be concentrated in two regions and is observed in two different seasons, manifesting an abrupt shift of the mean rainfall zone during June-July: (i) near the Gulf of Guinea (about 5degreesN), intense convection and rainfall are seen during April-June and roughly follow the seasonality of SST in the tropical eastern Atlantic, and (ii) along the latitudes of about 10degreesN over the interior of the West African continent, a second intense rain belt begins to develop in July and remains there during the later summer season. This belt coexists with a northward-moving African easterly jet (AEJ) and its accompanying horizontal and vertical shear zones, the appearance and intensification of an upper-tropospheric tropical easterly jet (TEJ), and a strong low-level westerly flow. Westward-propagating wave signals [i. e., African easterly waves (AEWs)] dominate the synoptic-scale variability during July-September, in contrast to the evident eastward-propagating wave signals during May-June.
The abrupt shift of the mean rainfall zone thus turns out to be a combination of two different physical processes: (i) evident seasonal cycles in the tropical eastern Atlantic Ocean, which modulate convection and rainfall near the Gulf of Guinea by means of SST thermal forcing and SST-related meridional gradient; and ( ii) the interaction among the AEJ, TEJ, low-level westerly flow, moist convection, and AEWs during July-September, which modulates rainfall variability in the interior of West Africa, primarily within the ITCZ rain band. Evident seasonality in synoptic-scale wave signals is shown to be a good indication of this seasonal evolution.
C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA.
Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA.
RP Gu, GJ (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 912, Greenbelt, MD 20771 USA.
EM ggu@agnes.gsfc.nasa.gov
NR 47
TC 65
Z9 65
U1 0
U2 12
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0894-8755
EI 1520-0442
J9 J CLIMATE
JI J. Clim.
PD SEP
PY 2004
VL 17
IS 17
BP 3364
EP 3377
DI 10.1175/1520-0442(2004)017<3364:SEAVAW>2.0.CO;2
PG 14
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 855SW
UT WOS:000223995200008
ER
PT J
AU Bromwich, DH
Toracinta, ER
Wei, HL
Oglesby, RJ
Fastook, JL
Hughes, TJ
AF Bromwich, DH
Toracinta, ER
Wei, HL
Oglesby, RJ
Fastook, JL
Hughes, TJ
TI Polar MM5 simulations of the winter climate of the Laurentide Ice Sheet
at the LGM
SO JOURNAL OF CLIMATE
LA English
DT Article
ID LAST GLACIAL MAXIMUM; MESOSCALE PREDICTION SYSTEM; GENERAL-CIRCULATION
MODEL; FINITE-ELEMENT MODEL; ST-MICHAEL ISLAND; C-14 YR BP; REGIONAL
CLIMATE; INNUITIAN ICE; ATMOSPHERIC CIRCULATION; WESTERN ALASKA
AB Optimized regional climate simulations are conducted using the Polar MM5, a version of the fifth-generation Pennsylvania State University-NCAR Mesoscale Model (MM5), with a 60-km horizontal resolution domain over North America during the Last Glacial Maximum (LGM, 21 000 calendar years ago), when much of the continent was covered by the Laurentide Ice Sheet (LIS). The objective is to describe the LGM annual cycle at high spatial resolution with an emphasis on the winter atmospheric circulation. Output from a tailored NCAR Community Climate Model version 3 (CCM3) simulation of the LGM climate is used to provide the initial and lateral boundary conditions for Polar MM5. LGM boundary conditions include continental ice sheets, appropriate orbital forcing, reduced CO2 concentration, paleovegetation, modified sea surface temperatures, and lowered sea level.
Polar MM5 produces a substantially different atmospheric response to the LGM boundary conditions than CCM3 and other recent GCM simulations. In particular, from November to April the upper-level flow is split around a blocking anticyclone over the LIS, with a northern branch over the Canadian Arctic and a southern branch impacting southern North America. The split flow pattern is most pronounced in January and transitions into a single, consolidated jet stream that migrates northward over the LIS during summer. Sensitivity experiments indicate that the winter split flow in Polar MM5 is primarily due to mechanical forcing by LIS, although model physics and resolution also contribute to the simulated flow configuration.
Polar MM5 LGM results are generally consistent with proxy climate estimates in the western United States, Alaska, and the Canadian Arctic and may help resolve some long-standing discrepancies between proxy data and previous simulations of the LGM climate.
C1 Ohio State Univ, Byrd Polar Res Ctr, Polar Meteorol Grp, Columbus, OH 43210 USA.
Ohio State Univ, Dept Geog, Atmospher Sci Program, Columbus, OH 43210 USA.
Natl Ctr Environm Predict, Camp Springs, MD USA.
NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL 35812 USA.
Univ Maine, Inst Quaternay & Climate Studies, Orono, ME USA.
RP Bromwich, DH (reprint author), Ohio State Univ, Byrd Polar Res Ctr, Polar Meteorol Grp, 1090 Carmack Rd, Columbus, OH 43210 USA.
EM bromwich@polarmet1.mps.ohio-state.edu
RI Bromwich, David/C-9225-2016
NR 68
TC 62
Z9 62
U1 0
U2 14
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0894-8755
J9 J CLIMATE
JI J. Clim.
PD SEP
PY 2004
VL 17
IS 17
BP 3415
EP 3433
DI 10.1175/1520-0442(2004)017<3415:PMSOTW>2.0.CO;2
PG 19
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 855SW
UT WOS:000223995200011
ER
PT J
AU Sankovic, JM
Kadambi, JR
Mehta, M
Smith, WA
Wernet, MP
AF Sankovic, JM
Kadambi, JR
Mehta, M
Smith, WA
Wernet, MP
TI PIV investigations of the flow field in the volute of a rotary blood
pump
SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME
LA English
DT Article
ID PARTICLE IMAGE VELOCIMETRY; VENTRICULAR ASSIST DEVICE; SPEED VIDEO
CAMERA; CENTRIFUGAL PUMP; VISUALIZATION; VELOCITY; FUTURE
AB A full-size acrylic model of a rotary blood pump was developed in order to utilize Particle Image Velocimetry (PIV) to make measurements of the fluid velocities and turbulent stresses throughout the device. The development of an understanding of the hemodynamics within the blood pump is critical to the development and validation of computational models. A blood analog solution, consisting of sodium iodide solution and glycerin, was developed to match physiological kinematic viscosity. The refractive indecies of the fluid, the pump casing, and the impeller were matched to,facilitate the use of PIV to make velocity measurements. Velocity measurements made in the volute exit/diffuser region are presented for pumps speeds of 3000-3850 rpm. At each speed data were obtained at a physiological pressure of 12 kPa and at a maximum flow condition. Four hundred data pairs were used,for each resultant mean velocity vector value, representing greater than an order of magnitude more data pairs than reported previously in the literature on similar devices and resulting in velocity uncertainty levels of approximately +/-2.9%.
C1 Case Western Reserve Univ, Dept Biomed Engn, Cleveland, OH 44106 USA.
NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA.
Case Western Reserve Univ, Dept Mech & Aerosp Engn, Cleveland, OH 44106 USA.
Cleveland Clin Fdn, Dept Biomed Engn, Lerner Res Ctr, Cleveland, OH 44195 USA.
RP Sankovic, JM (reprint author), Case Western Reserve Univ, Dept Biomed Engn, 10900 Euclid Ave, Cleveland, OH 44106 USA.
EM john.m.sankovic@nasa.gov
NR 22
TC 7
Z9 7
U1 2
U2 9
PU ASME-AMER SOC MECHANICAL ENG
PI NEW YORK
PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA
SN 0098-2202
J9 J FLUID ENG-T ASME
JI J. Fluids Eng.-Trans. ASME
PD SEP
PY 2004
VL 126
IS 5
BP 730
EP 734
DI 10.1115/1.1789529
PG 5
WC Engineering, Mechanical
SC Engineering
GA 880QY
UT WOS:000225805500004
ER
PT J
AU Abdol-Hamid, KS
Pao, SP
Massey, SJ
Elmiligui, A
AF Abdol-Hamid, KS
Pao, SP
Massey, SJ
Elmiligui, A
TI Temperature corrected turbulence model for high temperature jet flow
SO JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME
LA English
DT Article
AB It is well known that the two-equation turbulence models under-predict mixing in the shear layer for high temperature jet flows. These turbulence models were developed and calibrated for room temperature, low Mach number and plane mixing layer flows. In the present study, four existing modifications to the two-equation turbulence model are implemented in PAB3D and their effect is assessed for high temperature jet flows. In addition, a new temperature gradient correction to the eddy viscosity term is tested and calibrated. The new model was found to be in the best agreement with experimental data for subsonic and supersonic jet flows at both low and high temperatures.
C1 NASA, Langley Res Ctr, Configurat Aerodynam Branch, Hampton, VA 23681 USA.
Eagle Aeronaut Inc, Hampton, VA 23669 USA.
Analyt Serv & Mat Inc, Hampton, VA 23660 USA.
RP Abdol-Hamid, KS (reprint author), NASA, Langley Res Ctr, Configurat Aerodynam Branch, MS 499, Hampton, VA 23681 USA.
NR 18
TC 14
Z9 15
U1 0
U2 3
PU ASME-AMER SOC MECHANICAL ENG
PI NEW YORK
PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA
SN 0098-2202
J9 J FLUID ENG-T ASME
JI J. Fluids Eng.-Trans. ASME
PD SEP
PY 2004
VL 126
IS 5
BP 844
EP 850
DI 10.1115/1.1782266
PG 7
WC Engineering, Mechanical
SC Engineering
GA 880QY
UT WOS:000225805500017
ER
PT J
AU Zhou, YH
Yan, XH
Ding, XL
Liao, XH
Zheng, DW
Liu, WT
Pan, JY
Fang, MQ
He, MX
AF Zhou, YH
Yan, XH
Ding, XL
Liao, XH
Zheng, DW
Liu, WT
Pan, JY
Fang, MQ
He, MX
TI Excitation of non-atmospheric polar motion by the migration of the
Pacific Warm Pool
SO JOURNAL OF GEODESY
LA English
DT Article
DE polar motion; Western Pacific Warm Pool; excitation
ID EL-NINO; ANGULAR-MOMENTUM; EARTH ROTATION; LENGTH; OSCILLATION; SIGNALS;
WOBBLE; VARIABILITIES; EVENTS
AB Changes in the annual variation of the Earth's polar motion are found to be largely caused by the variation of the atmospheric angular momentum (AAM). Recent simulation results of oceanic general circulation models further suggest global oceanic effects on the annual polar motion in addition to the atmosphere. In comparison with previous model studies of global oceanic effects, this research particularly singles out a large-scale ocean anomaly and investigates its effect on the annual polar motion, determined from satellite observations of the movement of the Western Pacific Warm Pool (WPWP). Although the scale of the warm pool is much smaller than that of the solid Earth, analysis of the non-atmospheric polar motion excitation has shown that the WPWP contributes non-negligibly to the annual polar motion. The analysis consists of over 30 years of WPWP data (1970-2000) and shows values of polar motion excitation for the x-component of (2.5 mas, -79degrees) and for the gamma-component of (0.6 mas, 173degrees). Comparison of this result with the total geodetic non-atmospheric polar motion excitation of (10.3 mas, 59degrees) for the x-component and (10.6 mas, 62degrees) for the gamma-component shows the significance of the WPWP. Changes in the Earth's polar motion have attracted significant attention, not only because it is an important geodetic issue, but also because it has significant value as a global measure of variations within the hydrosphere, atmosphere, cryosphere, and solid Earth, and hence global changes.
C1 Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China.
Univ Delaware, Grad Coll Marine Studies, Newark, DE 19716 USA.
Hong Kong Polytech Univ, Dept Land Surveying & Geoinformat, Hong Kong, Hong Kong, Peoples R China.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Ocean Univ China, Ocean Remote Sensing Inst, Qingdao, Peoples R China.
Chinese Acad Sci, United Ctr Astrogeodynam Res, Shanghai, Peoples R China.
RP Zhou, YH (reprint author), Chinese Acad Sci, Shanghai Astron Observ, 80 Nandan Rd, Shanghai 200030, Peoples R China.
EM yhzhou@center.shao.ac.cn
RI Ding, Xiaoli/K-4596-2013
OI Ding, Xiaoli/0000-0002-5733-3629
NR 30
TC 5
Z9 5
U1 0
U2 3
PU SPRINGER
PI NEW YORK
PA 233 SPRING STREET, NEW YORK, NY 10013 USA
SN 0949-7714
J9 J GEODESY
JI J. Geodesy
PD SEP
PY 2004
VL 78
IS 1-2
BP 109
EP 113
DI 10.1007/s00190-004-0380-7
PG 5
WC Geochemistry & Geophysics; Remote Sensing
SC Geochemistry & Geophysics; Remote Sensing
GA 857DS
UT WOS:000224097000014
ER
PT J
AU Menon, PK
Sweriduk, GD
Bilimoria, KD
AF Menon, PK
Sweriduk, GD
Bilimoria, KD
TI New approach for modeling, analysis, and control of air traffic flow
SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS
LA English
DT Article; Proceedings Paper
CT AIAA Guidance, Navigation, and Control Conference
CY AUG 05-08, 2002
CL MONTEREY, CA
SP Amer Inst Aeronaut & Astronaut
ID CELL TRANSMISSION MODEL; KINEMATIC WAVES; HIGHWAY
AB An Eulerian approach to modeling air traffic flow is advanced. This modeling technique spatially aggregates air traffic to generate models of air traffic flow in a network of interconnected, one-dimensional control volumes. The approach simplifies the problem of characterizing the air traffic flow because the order of the corresponding airspace model depends only on the number of spatial control volumes used to represent the air traffic environment and not on the number of aircraft operating in it. Under a quasi-steady-state assumption, this process results in linear models of the air traffic environment. It is shown that analysis and design methods from linear control theory can be applied to this model to yield useful approaches for characterizing and controlling the air traffic flow.
C1 Optimal Synth Inc, Palo Alto, CA 94303 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Menon, PK (reprint author), Optimal Synth Inc, Palo Alto, CA 94303 USA.
NR 18
TC 44
Z9 49
U1 0
U2 8
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0731-5090
J9 J GUID CONTROL DYNAM
JI J. Guid. Control Dyn.
PD SEP-OCT
PY 2004
VL 27
IS 5
BP 737
EP 744
DI 10.2514/1.2556
PG 8
WC Engineering, Aerospace; Instruments & Instrumentation
SC Engineering; Instruments & Instrumentation
GA 854BT
UT WOS:000223875900001
ER
PT J
AU Shin, JY
Wu, NE
Belcastro, C
AF Shin, JY
Wu, NE
Belcastro, C
TI Adaptive linear parameter varying control synthesis for actuator failure
SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS
LA English
DT Article
ID SYSTEMS; DESIGN; ACCOMMODATION; ALGORITHMS; AXIS
AB A robust linear parameter varying (LPV) control synthesis is carried out for a Highly Maneuverable Aircraft Technology (HiMAT) vehicle subject to loss of control effectiveness. The scheduling parameter is selected to be a function of the estimates of the control effectiveness factors. The estimates are provided online by a two-stage adaptive Kalman filter estimator. The inherent conservatism of the LPV design is reduced through the use of a scaling factor on the uncertainty block that represents the estimation errors of the effectiveness factors. Simulations of the controlled system with the online estimator show that a superior fault tolerance can be achieved.
C1 Natl Inst Aerosp, Hampton, VA 23666 USA.
SUNY Binghamton, Dept Elect & Comp Engn, Binghamton, NY 13902 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Natl Inst Aerosp, Hampton, VA 23666 USA.
NR 21
TC 21
Z9 21
U1 2
U2 6
PU AMER INST AERONAUTICS ASTRONAUTICS
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0731-5090
EI 1533-3884
J9 J GUID CONTROL DYNAM
JI J. Guid. Control Dyn.
PD SEP-OCT
PY 2004
VL 27
IS 5
BP 787
EP 794
DI 10.2514/1.9430
PG 8
WC Engineering, Aerospace; Instruments & Instrumentation
SC Engineering; Instruments & Instrumentation
GA 854BT
UT WOS:000223875900007
ER
PT J
AU Roithmayr, CM
Karlgaard, CD
Kumar, RR
Bose, DM
AF Roithmayr, CM
Karlgaard, CD
Kumar, RR
Bose, DM
TI Integrated power and attitude control with spacecraft flywheels and
control moment gyroscopes
SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS
LA English
DT Article; Proceedings Paper
CT AAS/AIAA 13th Space Flight Mechanics Meeting
CY FEB 09-13, 2003
CL Ponce, PR
SP AAS, Amer Inst Aeronaut & Astronaut
ID TRACKING
AB A law is designed for simultaneous control of the orientation of an Earth-pointing spacecraft, the energy stored by counter-rotating flywheels, and the angular momentum of the flywheels and control moment gyroscopes used together as an integrated set of actuators for attitude control. General, nonlinear equations of motion are presented in vector-dyadic form and used to obtain approximate expressions that are then linearized in preparation for design of control laws that include feedback of flywheel kinetic energy error as a means of compensating for damping exerted by rotor bearings. Two flywheel steering laws are developed such that torque commanded. by an attitude control law is applied while energy is stored or discharged at the required rate. With use of the International Space Station as an example, numerical simulations are performed to demonstrate control about a torque equilibrium attitude and to illustrate the benefits of kinetic energy error feedback.
C1 NASA, Langley Res Ctr, Spacecraft & Sensors Branch, Hampton, VA 23681 USA.
Analyt Mech Associates Inc, Hampton, VA 23666 USA.
RP Roithmayr, CM (reprint author), NASA, Langley Res Ctr, Spacecraft & Sensors Branch, Mail Stop 328, Hampton, VA 23681 USA.
EM c.m.roithmayr@larc.nasa.gov; karlgaard@ama-inc.com; renji@ama-inc.com;
dmbose@ama-inc.com
NR 27
TC 13
Z9 14
U1 0
U2 0
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0731-5090
J9 J GUID CONTROL DYNAM
JI J. Guid. Control Dyn.
PD SEP-OCT
PY 2004
VL 27
IS 5
BP 859
EP 873
DI 10.2514/1.2096
PG 15
WC Engineering, Aerospace; Instruments & Instrumentation
SC Engineering; Instruments & Instrumentation
GA 854BT
UT WOS:000223875900014
ER
PT J
AU Matsuoka, MP
Gharrett, AJ
Wilmot, RL
Smoker, WW
AF Matsuoka, MP
Gharrett, AJ
Wilmot, RL
Smoker, WW
TI Genetic linkage mapping of allozyme loci in even- and odd-year pink
salmon (Oncorhynchus gorbuscha)
SO JOURNAL OF HEREDITY
LA English
DT Article
ID MALATE DEHYDROGENASE LOCI; JOINT SEGREGATION;
ASPARTATE-AMINOTRANSFERASE; SALVELINUS-FONTINALIS; RECOMBINATION RATES;
BIOCHEMICAL LOCI; ENZYME LOCI; BROOK TROUT; INHERITANCE; FISHES
AB We constructed genetic linkage maps of allozyme loci in even- and odd-year pink salmon (Oncorhynchus gorbuscha), using the total of 320 families (each female was crossed with two different males, and 80 females and 160 males were used for each of even year and odd year). The maps include eight linkage groups involving 22 loci. We observed substantial variation in recombination frequencies among different families within broodline and between sexes within broodlines. In the linkage analysis between sAAT-3* and sMDH-B1,2*, two even-year families and one odd-year family exhibited evidence of association, but two even-year and one odd-year families did not. Recombination rate tends to be reduced in males in pink salmon. The ratio of recombination rate (female/male), which ranged from 1.7 to infinity, averaged 2.8 in the even-year crosses and 3.2 in the odd-year crosses. The linkage groups (LG) I and II involving sAAT and mAH loci, which probably duplicated in the recent tetraploidization event, and the orders of loci in the LGs I (sAAT-3* --> mAH-4*) and II (mAH-3* --> sAAT-4*) were reversed, suggesting the possible paracentric inversion during salmonid evolution after the duplication.
C1 Univ Alaska Fairbanks, Sch Fisheries & Ocean Sci, Juneau Ctr, Juneau, AK 99801 USA.
NOAA, Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Juneau, AK 99801 USA.
RP Matsuoka, MP (reprint author), CNR, Inst Marine Biosci, 1411 Oxfoprd St, Halifax, NS B3H 3Z1, Canada.
EM makoto.matsuoka@nrc-cnrc.gc.ca
NR 41
TC 5
Z9 6
U1 1
U2 3
PU OXFORD UNIV PRESS INC
PI CARY
PA JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA
SN 0022-1503
J9 J HERED
JI J. Hered.
PD SEP
PY 2004
VL 95
IS 5
BP 421
EP 429
DI 10.1093/jhered/esh069
PG 9
WC Evolutionary Biology; Genetics & Heredity
SC Evolutionary Biology; Genetics & Heredity
GA 856XK
UT WOS:000224079200007
PM 15388769
ER
PT J
AU Richardson, LJ
Bonner, CE
Lewis, J
Loutts, GB
Rodriguez, WJ
Walsh, BM
AF Richardson, LJ
Bonner, CE
Lewis, J
Loutts, GB
Rodriguez, WJ
Walsh, BM
TI Temperature dependence on the cross-relaxation rates in Tm3+ doped
strontium fluorapatite
SO JOURNAL OF LUMINESCENCE
LA English
DT Article
DE absorption spectra; emission spectra; laser materials; thulium ions;
fluorapatites; time-resolved emission
ID ENERGY-TRANSFER; DYNAMICS; LASER; EFFICIENT; YAG; HO; EXCITATION;
THULIUM; ERBIUM; IONS
AB The cross-relaxation dynamics of Tm3+-doped strontium fluorapatites (S-FAP) has been examined using time-resolved fluorescence srectroscopy. The temperature dependence of the fluorescence lifetime crystal suggests a dipole-dipole interaction between the Tm3+ ions and the energy is transported by an incoherent hopping mechanism. The temperature dependence of the fluorescence lifetime suggests this incoherent hopping mechanism is used to bridge the energy mismatch between emission from the donor and the energy required for absorption by the acceptors. Using the energy transfer model of Agranovich, the cross-relaxation rate was determined from the emission decay dynamics of the H-3(4) --> H-3(6) transition. The observed cross-relaxation rate ranged from 11 s(-1) at 10 K to 81 s(-1) at 200 K for 0.21 at% Tm3+ in S-FAP an energy barrier of 44.3 cm(-1). The model suggest that rates of 10(6) ion hops s(-1) for 1 at% Tm3+ in S-FAP could be achieved, rendering this material a potentially efficient laser medium. (C) 2004 Elsevier B.V. All rights reserved.
C1 Norfolk State Univ, Mat Res Ctr, Norfolk, VA 23504 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Bonner, CE (reprint author), Norfolk State Univ, Mat Res Ctr, 700 Pk Ave, Norfolk, VA 23504 USA.
EM cebonner@nsu.edu
NR 26
TC 2
Z9 2
U1 2
U2 2
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0022-2313
J9 J LUMIN
JI J. Lumines.
PD SEP
PY 2004
VL 109
IS 3-4
BP 129
EP 133
DI 10.1016/j.jlumin.2004.02.002
PG 5
WC Optics
SC Optics
GA 849AF
UT WOS:000223508900001
ER
PT J
AU Arepalli, S
Holmes, WA
Nikolaev, P
Hadjiev, VG
Scott, CD
AF Arepalli, S
Holmes, WA
Nikolaev, P
Hadjiev, VG
Scott, CD
TI A parametric study of single-wall carbon nanotube growth by laser
ablation
SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
LA English
DT Article
DE single-wall carbon nanotubes; laser ablation; SEM; TEM; Raman
spectroscopy
ID VAPORIZATION METHOD; FLUORESCENCE; TEMPERATURE; PLUME
AB Results of a parametric study of carbon nanotube production by the double-pulse laser oven process are presented. The effect of various operating parameters on the production of single-wall carbon nanotubes (SWCNTs) is estimated by characterizing the nanotube material using analytical techniques, including scanning electron microscopy, transmission electron microscopy, thermo gravimetric analysis and Raman spectroscopy. The study included changing the sequence of the laser pulses, laser energy, pulse separation, type of buffer gas used, operating pressure, flow rate, inner tube diameter, as well as its material, and oven temperature. It was found that the material quality and quantity improve with deviation from normal operation parameters such as laser energy density higher than 1.5 j/cm(2), pressure lower than 67 kPa, and flow rates higher than 100 sccm. Use of helium produced mainly small diameter tubes and a lower yield. The diameter of SWCNTs decreases with decreasing oven temperature and lower flow rates.
C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
Univ Houston, Texas Ctr Superconduct & Adv Mat, Houston, TX 77204 USA.
NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA.
RP Arepalli, S (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 NASA Rd 1, Houston, TX 77058 USA.
RI Arepalli, Sivaram/A-5372-2010; Nikolaev, Pavel/B-9960-2009; Hadjiev,
Viktor/A-7069-2008
OI Hadjiev, Viktor/0000-0001-8579-9357
NR 30
TC 23
Z9 23
U1 2
U2 12
PU AMER SCIENTIFIC PUBLISHERS
PI STEVENSON RANCH
PA 25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA
SN 1533-4880
J9 J NANOSCI NANOTECHNO
JI J. Nanosci. Nanotechnol.
PD SEP
PY 2004
VL 4
IS 7
BP 762
EP 773
DI 10.1166/jnn.2004.087
PG 12
WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials
Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter
SC Chemistry; Science & Technology - Other Topics; Materials Science;
Physics
GA 864CS
UT WOS:000224611300014
PM 15570958
ER
PT J
AU Piacentini, R
Cede, A
AF Piacentini, R
Cede, A
TI Measurements of solar ultraviolet irradiance on inclined surfaces
SO JOURNAL OF OPTICS A-PURE AND APPLIED OPTICS
LA English
DT Article
DE solar; ultraviolet; erythemal; irradiance; inclined surface
ID TILTED SURFACES; RADIATION; MODEL
AB We present pyranometer and biometer results of total solar UV irradiance (295-385 nm) and erythemal irradiance measured on inclined surfaces in Rosario, Argentina (32degrees57' S, 60degrees38' W, 25 m a.s.l.), on clear-sky days near the southern hemisphere summer and winter solstices and spring equinox. The pyranometer and a biometer were placed on a rotation device in order to modify the detector inclination in the solar plane. We determined in detail a systematic difference between the detector inclination at the highest intensity and the detector inclination in the Sun direction. The maximum intensity was always registered at a detector inclination greater than the solar elevation. This can be explained by the varying relation between the diffuse and direct contributions to the irradiance at different inclinations. For total UV irradiance, the absolute difference between the detector inclination at maximum intensity and the solar elevation is less than 120 for solar elevations greater than 30degrees and for erythemal irradiance less than 20degrees. The relative difference of the intensities is less than 2% for total UV irradiance and less than 5% for erythemal irradiance. For smaller solar elevations both differences grow rapidly.
C1 Univ Nacl Rosario, CONICET, Inst Fis Rosario, RA-2000 Rosario, Santa Fe, Argentina.
Fac Ciencias Exactas Ingn & Arimensura, RA-2000 Rosario, Santa Fe, Argentina.
Sci Syst & Applicat Inc, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
RP Piacentini, R (reprint author), Univ Nacl Rosario, CONICET, Inst Fis Rosario, 27 Febrero 210bis, RA-2000 Rosario, Santa Fe, Argentina.
EM ruben@ifir.edu.ar
NR 14
TC 0
Z9 0
U1 0
U2 1
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 1464-4258
J9 J OPT A-PURE APPL OP
JI J. Opt. A-Pure Appl. Opt.
PD SEP
PY 2004
VL 6
IS 9
BP 819
EP 823
AR PII S1464-4258(04)77169-X
DI 10.1088/1464-4258/6/9/001
PG 5
WC Optics
SC Optics
GA 858HI
UT WOS:000224182500001
ER
PT J
AU Smith, W
Foster, I
Taylor, V
AF Smith, W
Foster, I
Taylor, V
TI Predicting application run times with historical information
SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING
LA English
DT Article
AB We present a technique for predicting the run times of parallel applications based upon the run times of "similar" applications that have executed in the past. The novel aspect of our work is the use of search techniques to determine those application characteristics that yield the best definition of similarity for the purpose of making predictions. We use four workloads recorded from parallel computers at Argonne National Laboratory, the Cornell Theory Center, and the San Diego Supercomputer Center to evaluate the effectiveness of our approach. We show that on these workloads our techniques achieve predictions that are between 21 and 64 percent better than those achieved by other techniques: our approach achieves mean prediction errors that are between 29 and 59 percent of mean application run times. (C) 2004 Published by Elsevier Inc.
C1 Texas A&M Univ, Dept Comp Sci, College Stn, TX 77843 USA.
NASA, Ames Res Ctr, Comp Sci Corp, Adv Supercomp Div, Moffett Field, CA 94035 USA.
Univ Chicago, Dept Comp Sci, Chicago, IL 60637 USA.
RP Smith, W (reprint author), Texas A&M Univ, Dept Comp Sci, College Stn, TX 77843 USA.
EM wwsmith@arc.nasa.gov; foster@mcs.anl.gov; taylor@cs.tamu.edu
NR 13
TC 35
Z9 38
U1 0
U2 0
PU ACADEMIC PRESS INC ELSEVIER SCIENCE
PI SAN DIEGO
PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA
SN 0743-7315
J9 J PARALLEL DISTR COM
JI J. Parallel Distrib. Comput.
PD SEP
PY 2004
VL 64
IS 9
BP 1007
EP 1016
DI 10.1016/j.jpdc.2004.06.008
PG 10
WC Computer Science, Theory & Methods
SC Computer Science
GA 854UH
UT WOS:000223928400001
ER
PT J
AU Qu, TD
Lindstrom, EJ
AF Qu, TD
Lindstrom, EJ
TI Northward intrusion of Antarctic intermediate water in the western
Pacific
SO JOURNAL OF PHYSICAL OCEANOGRAPHY
LA English
DT Article
ID SOUTH CHINA SEA; EQUATORIAL PACIFIC; OCEAN CIRCULATION; MINDANAO
CURRENT; PHILIPPINE SEA; COAST
AB The northward intrusion of Antarctic Intermediate Water (AAIW) is examined using historical data combined with synoptic observations from a repeated hydrographic section in the western Pacific Ocean. The results of this analysis suggest that AAIW is traced as a salinity minimum to only about 15degreesN via the New Guinea Coastal Undercurrent and the Mindanao Undercurrent. There is no northward extension of AAIW farther to the north along the western boundary. Although relatively high oxygen water does exist in the Okinawa Trough, it is connected with high-oxygen water in the South China Sea (SCS) through the Luzon Strait but not from the south as an extension of AAIW. Local circulation seems to play an essential role in localizing the oxygen maximum in the SCS. Evidence exists to suggest that high-oxygen water enters the SCS as part of the Pacific deep water around the still depth (similar to2000 m) of the Luzon Strait; from there, part of it upwells and is entrained into shallower isopycnal surfaces by vertical mixing and eventually flows back to the Pacific through the Luzon Strait at depths of AAIW.
C1 Univ Hawaii Manoa, IPRC SOEST, Honolulu, HI 96822 USA.
NASA, Off Earth Sci, Washington, DC 20546 USA.
RP Qu, TD (reprint author), Univ Hawaii Manoa, IPRC SOEST, 2525 Correa Rd, Honolulu, HI 96822 USA.
EM tangdong@hawaii.edu
NR 36
TC 52
Z9 59
U1 2
U2 7
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0022-3670
J9 J PHYS OCEANOGR
JI J. Phys. Oceanogr.
PD SEP
PY 2004
VL 34
IS 9
BP 2104
EP 2118
DI 10.1175/1520-0485(2004)034<2104:NIOAIW>2.0.CO;2
PG 15
WC Oceanography
SC Oceanography
GA 856WE
UT WOS:000224075300012
ER
PT J
AU Sridhar, KR
Iacomini, CS
Finn, JE
AF Sridhar, KR
Iacomini, CS
Finn, JE
TI Combined H2O/CO2 solid oxide electrolysis for mars in situ resource
utilization
SO JOURNAL OF PROPULSION AND POWER
LA English
DT Article
ID RUTHENIUM CATALYST; CARBON-DIOXIDE; HYDROGEN; CELL
AB Mars sample return missions and eventual human missions will both benefit from using Martian resources to produce Earth-return propellant and life support consumables. A new architecture for an in situ propellant production plant is introduced that utilizes solid oxide electrolysis to perform the combined electrolysis of both water and carbon dioxide. The proposed system produces methane via a Sabatier reactor and oxygen via electrolysis in the optimal oxidizer-to-fuel mixture ratio with the capability to produce extra oxygen for life support needs. Each major component of the combined electrolysis/Sabatier architecture is modeled to assess the feasibility and size of such a propellant production plant. Sample return and human missions are analyzed with the models. Results demonstrate that combined electrolysis enables a competitive system for in situ resource utilization as well as an ease of scaling for sample return vs human missions. When compared to published data of other oxygen/methane-producing architectures, the proposed system is shown to be less massive while comparable in power. Other advantages of implementing combined electrolysis in a propellant production plant are discussed.
C1 Univ Arizona, Dept Aerosp & Mech Engn, Tucson, AZ 85721 USA.
NASA, Ames Res Ctr, Dept Aerosp & Mech Engn, Moffett Field, CA 94035 USA.
RP Sridhar, KR (reprint author), Univ Arizona, Dept Aerosp & Mech Engn, Tucson, AZ 85721 USA.
NR 39
TC 17
Z9 18
U1 2
U2 21
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0748-4658
J9 J PROPUL POWER
JI J. Propul. Power
PD SEP-OCT
PY 2004
VL 20
IS 5
BP 892
EP 901
DI 10.2514/1.3480
PG 10
WC Engineering, Aerospace
SC Engineering
GA 854VV
UT WOS:000223932600015
ER
PT J
AU Mason, LS
AF Mason, LS
TI A power conversion concept for the Jupiter Icy Moons Orbiter
SO JOURNAL OF PROPULSION AND POWER
LA English
DT Article; Proceedings Paper
CT 1st International Energy Conversion Engineering Conference
CY AUG 17-21, 2003
CL Portsmouth, VA
AB An analytical study was performed to compare design options for a reactor power system that could be utilized on a Jupiter Icy Moons Orbiter mission employing nuclear electric propulsion. The resulting concept uses a liquid-metal cooled reactor and closed-Brayton-cycle power conversion. The power conversion system consists of two, independent Brayton converters each capable of providing the full design output power. The converter design is based on state-of-the-art superalloy hot-end construction permitting turbine inlet temperatures of 1150 K and cycle efficiencies in excess of 20%. The waste heat-rejection system includes a mechanically pumped liquid-metal heat-transport loop and water heat-pipe radiator panels. The power management and distribution system provides the power electronics, electrical controls, switchgear, and cabling to deliver 400 Vac (volts alternating current) to the electric propulsion system and 120 Vdc (volts direct current) to the spacecraft bus. This paper discusses some of the key tradeoffs considered in arriving at the proposed concept and provides a summary of the power system performance and mass.
C1 NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Mason, LS (reprint author), NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA.
EM Lee.S.Mason@nasa.gov
NR 7
TC 13
Z9 13
U1 0
U2 4
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0748-4658
J9 J PROPUL POWER
JI J. Propul. Power
PD SEP-OCT
PY 2004
VL 20
IS 5
BP 902
EP 910
DI 10.2514/1.5805
PG 9
WC Engineering, Aerospace
SC Engineering
GA 854VV
UT WOS:000223932600016
ER
PT J
AU Paxson, DE
AF Paxson, DE
TI Performance evaluation method for ideal airbreathing pulse detonation
engines
SO JOURNAL OF PROPULSION AND POWER
LA English
DT Article
C1 NASA John H Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Paxson, DE (reprint author), NASA John H Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA.
NR 13
TC 11
Z9 12
U1 0
U2 1
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0748-4658
J9 J PROPUL POWER
JI J. Propul. Power
PD SEP-OCT
PY 2004
VL 20
IS 5
BP 945
EP 947
DI 10.2514/1.11426
PG 3
WC Engineering, Aerospace
SC Engineering
GA 854VV
UT WOS:000223932600021
ER
PT J
AU Devi, VM
Benner, DC
Smith, MAH
Rinsland, CP
Sharpe, SW
Sams, RL
AF Devi, VM
Benner, DC
Smith, MAH
Rinsland, CP
Sharpe, SW
Sams, RL
TI A multispectrum analysis of the 2v(2) spectral region of
(HCN)-C-12-N-14: intensities, broadening and pressure-shift coefficients
SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
LA English
DT Article
DE HCN; HCN 2v(2) band; infrared spectra; fourier transform infrared (FTIR)
spectroscopy; absolute intensity; broadening and shifts
ID INTEGRATED-INTENSITIES; WATER-VAPOR; V(1) BAND; HCN; TEMPERATURE;
WIDTHS; TRANSITION; PARAMETERS; LINES; CM-1
AB High-resolution (0.005 cm(-1)) infrared absorption spectra of HCN in the 2v(2) band region near 1411 cm(-1) have been recorded at room temperature using the Bruker IFS120HR Fourier transform spectrometer located at Pacific Northwest National Laboratory. Four spectra of high-purity (99.8%) HCN together with three spectra of lean mixtures (similar to3%) of HCN in dry air were simultaneously fit using a multispectrum nonlinear least-squares procedure. The analysis yielded room temperature values for absolute intensities, self- and air-broadening coefficients, and self- and air-induced pressure shift coefficients for numerous lines in the 2v(2)(0) band of (HCN)-C-12-N-14. In addition, intensities, self- and air-broadening coefficients for several lines of the 3v(2)(1)-v(2)(1) hot band, as well as intensities for a number of lines in the 2v(0)(2) band of (HCN)-C-13-N-14, were also determined. Since there are no previous measurements of broadening and shift parameters reported in the 2v(2)(0) band, our results are compared with values recently determined in the v, band of (HCN)-C-12-N-14 and with current HITRAN values. (C) 2004 Elsevier Ltd. All rights reserved.
C1 Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA.
NASA, Langley Res Ctr, Hampton, VA 23681 USA.
PNNL, Pacific NW Natl Lab, Richland, WA 99352 USA.
RP Devi, VM (reprint author), Coll William & Mary, Dept Phys, Box 8795, Williamsburg, VA 23187 USA.
EM m.d.venkataraman@larc.nasa.gov
NR 24
TC 14
Z9 14
U1 1
U2 1
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0022-4073
J9 J QUANT SPECTROSC RA
JI J. Quant. Spectrosc. Radiat. Transf.
PD SEP 1
PY 2004
VL 87
IS 3-4
BP 339
EP 366
DI 10.1016/j.jqsrt.2004.03.002
PG 28
WC Optics; Spectroscopy
SC Optics; Spectroscopy
GA 836KA
UT WOS:000222553200009
ER
PT J
AU Horvath, TJ
Heiner, NC
Olguin, DM
AF Horvath, TJ
Heiner, NC
Olguin, DM
TI Wake closure and afterbody heating on a mars sample return orbiter
SO JOURNAL OF SPACECRAFT AND ROCKETS
LA English
DT Article
ID HYPERSONIC WAKES; AEROTHERMODYNAMICS
AB Aeroheating wind-tunnel tests were conducted on a 0.028-scale model of an orbiter concept considered for a possible Mars sample return mission. The primary experimental objectives were to characterize hypersonic near-wake closure and to determine if shear layer impingement would occur on the proposed orbiter afterbody at incidence angles necessary for a Martian aerocapture maneuver. Global heat transfer mappings, surface streamline patterns, and shock shapes were obtained in the NASA Langley Research Center 20-Inch Mach 6 Air and CF4 Tunnels for postnormal shock Reynolds numbers (based on forebody diameter) ranging from 1.4 x 10(3) to 4.15 x 10(5), angles of attack ranging from -5 to 10 deg at 0-, 3-, and 6-deg sideslip, and normal shock density ratios of 5 and 12. Laminar, transitional, and turbulent shear layer impingement on the cylindrical afterbody was inferred from the measurements and resulted in a localized heating maximum that ranged from 40 to 75% of the reference forebody stagnation point heating.
C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Horvath, TJ (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA.
NR 43
TC 4
Z9 4
U1 0
U2 0
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0022-4650
J9 J SPACECRAFT ROCKETS
JI J. Spacecr. Rockets
PD SEP-OCT
PY 2004
VL 41
IS 5
BP 705
EP 715
DI 10.2514/1.13102
PG 11
WC Engineering, Aerospace
SC Engineering
GA 863CZ
UT WOS:000224539500001
ER
PT J
AU Nygaard, TA
Meakin, RL
AF Nygaard, TA
Meakin, RL
TI Aerodynamic analysis of a spinning missile with dithering canards
SO JOURNAL OF SPACECRAFT AND ROCKETS
LA English
DT Article
ID NUMERICAL-SIMULATION; GRIDS
AB A generic spinning missile with dithering canards is used to demonstrate the utility of an overset structured grid approach for simulating the aerodynamics of rolling airframe missile systems. A grid convergence study and assessment of viscous effects shows that a medium-resolution viscous grid with 8 million grid points provides a good compromise between solution accuracy and throughput. Viscous effects should be included in detailed studies to capture the interaction between the inboard canard vortex and the fuselage and tail boundary layers. The computed results agree well with experimental data. A database of cases with variation of angle of attack and the strength of control authority of a pitch-up maneuver is computed to evaluate missile performance. The case throughput rates are sufficient to contemplate population of aerodynamic databases with Navier-Stokes computations. Overall, the structured overset grid approach enables accurate and efficient simulation of rolling airframe missile configurations that involve relative motion between system components.
C1 Eloret Corp, Sunnyvale, CA 94087 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Nygaard, TA (reprint author), Eloret Corp, Sunnyvale, CA 94087 USA.
NR 10
TC 6
Z9 8
U1 0
U2 3
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0022-4650
J9 J SPACECRAFT ROCKETS
JI J. Spacecr. Rockets
PD SEP-OCT
PY 2004
VL 41
IS 5
BP 726
EP 734
DI 10.2514/1.13075
PG 9
WC Engineering, Aerospace
SC Engineering
GA 863CZ
UT WOS:000224539500003
ER
PT J
AU Johnson, WR
Longuski, JM
AF Johnson, WR
Longuski, JM
TI Six-degree-of-freedom modeling of semi-autonomous attitude control
during aerobraking
SO JOURNAL OF SPACECRAFT AND ROCKETS
LA English
DT Article
ID MARS GLOBAL SURVEYOR; EXPLORATION; DESIGN
AB The automation of a Mars aerobraking vehicle that uses reaction wheels for attitude and angular momentum control during atmospheric flythrough is investigated. In a previous study, single-axis control laws were developed for minimum onboard instrumentation to compensate for large variations in entry time and atmospheric density. Modifications of those control laws to provide two-axis control in high-fidelity simulations that include six degrees of freedom, nearly ideal reaction wheels, spherical harmonics, and oblate atmosphere are now tested. Preliminary results indicate that our approach may be highly practical for an autonomous aerobraking mission at Mars.
C1 Purdue Univ, W Lafayette, IN 47907 USA.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Johnson, WR (reprint author), Purdue Univ, W Lafayette, IN 47907 USA.
NR 18
TC 2
Z9 2
U1 0
U2 2
PU AMER INST AERONAUT ASTRONAUT
PI RESTON
PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA
SN 0022-4650
J9 J SPACECRAFT ROCKETS
JI J. Spacecr. Rockets
PD SEP-OCT
PY 2004
VL 41
IS 5
BP 797
EP 804
DI 10.2514/1.13078
PG 8
WC Engineering, Aerospace
SC Engineering
GA 863CZ
UT WOS:000224539500011
ER
PT J
AU McCurdy, DA
Brown, SA
Hilliard, RD
AF McCurdy, DA
Brown, SA
Hilliard, RD
TI Subjective response of people to simulated sonic booms in their homes
SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
LA English
DT Article
AB In order to determine the effect of the number of sonic boom occurrences on annoyance, a computer-based system was developed for studying the subjective response of people to the occurrence of simulated sonic booms in their homes. The system provided a degree of control over the noise exposure not found in community surveys and a degree of situational realism not available in the laboratory. A system was deployed for eight weeks in each of 33 homes. Each day from 4 to 63 sonic booms were played as the test subject went about his or her normal activities. At the end of the day, the test subjects rated their annoyance to the sonic booms heard during the day: The sonic booms consisted of different combinations of waveforms, levels, and occurrence rates. The experiment confirmed that the increase in annoyance resulting from multiple occurrences can be modeled by the addition of the term "10 * log(number of occurrences) " to the sonic boom level. Of several noise metrics considered, perceived level was the best annoyance predictor. Comparisons of the subjective responses to the different sonic boom waveforms found no differences that were not accounted for by the noise metrics.
C1 NASA, Langley Res Ctr, Struct Acoust Branch, Hampton, VA 23681 USA.
NASA, Langley Res Ctr, Syst Anal Branch, Hampton, VA 23681 USA.
Wyle Labs, Hampton, VA 23666 USA.
RP McCurdy, DA (reprint author), NASA, Langley Res Ctr, Struct Acoust Branch, MS 463, Hampton, VA 23681 USA.
EM d.a.mccurdy@nasa.gov
NR 15
TC 4
Z9 4
U1 0
U2 0
PU ACOUSTICAL SOC AMER AMER INST PHYSICS
PI MELVILLE
PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA
SN 0001-4966
J9 J ACOUST SOC AM
JI J. Acoust. Soc. Am.
PD SEP
PY 2004
VL 116
IS 3
BP 1573
EP 1584
DI 10.1121/1.1781189
PG 12
WC Acoustics; Audiology & Speech-Language Pathology
SC Acoustics; Audiology & Speech-Language Pathology
GA 853OJ
UT WOS:000223836600028
PM 15478423
ER
PT J
AU Opila, EJ
Myers, DL
AF Opila, EJ
Myers, DL
TI Alumina volatility in water vapor at elevated temperatures
SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY
LA English
DT Article
ID GAS
AB The volatility of alumina in high-temperature water vapor was determined by a weight loss technique. Sapphire coupons were exposed at temperatures between 1250degrees and 1500degreesC, water partial pressures between 0.15 and 0.68 atm in oxygen, a total pressure of 1 atm, and flowing gas velocities of 4.4 cm/s. The water vapor pressure dependence of sapphire volatility was consistent with Al(OH)(3)(g) formation. The enthalpy of reaction to form Al(OH)(3)(g) from sapphire and water vapor was determined to be 210 +/- 20 Q/mol, comparing favorably to other studies. Microstructural examination of tested sapphire coupons revealed surface rearrangement consistent with a volatilization process.
C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
E Cent Univ, Dept Chem, Ada, OK 74820 USA.
RP Opila, EJ (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
NR 12
TC 50
Z9 51
U1 0
U2 11
PU WILEY-BLACKWELL
PI MALDEN
PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA
SN 0002-7820
J9 J AM CERAM SOC
JI J. Am. Ceram. Soc.
PD SEP
PY 2004
VL 87
IS 9
BP 1701
EP 1705
PG 5
WC Materials Science, Ceramics
SC Materials Science
GA 858LI
UT WOS:000224192900014
ER
PT J
AU Li, H
Morscher, GN
Lee, J
Lee, WY
AF Li, H
Morscher, GN
Lee, J
Lee, WY
TI Tensile and stress-rupture behavior of SiC/SiC minicomposite containing
chemically vapor deposited zirconia interphase
SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY
LA English
DT Article
ID CERAMIC-MATRIX COMPOSITES; METASTABLE TETRAGONAL ZIRCONIA;
MECHANICAL-PROPERTIES; NICALON FIBER; HI-NICALON; STRENGTH; FRACTURE;
PRESSURE; CARBON; GLASS
AB The tensile and stress-rupture behavior of SiC/SiC minicomposite containing a chemically vapor deposited (CVD) ZrO2 interphase was evaluated. Fractographic analyses showed that in situ fiber strength and minicomposite failure loads were strongly dependent on the phase contents and microstructure of the ZrO2 interphase. When the ZrO2 interphase structure possessed a weakly bonded interface within the dense ZrO2 interphase coating layer, the interphase sufficiently protected the fiber surface from processing degradation and promoted matrix crack deflection around the fibers. With this weakly bonded interphase, the stress-rupture properties of SiC/SiC minicomposite at 950degrees and 1200degreesC appeared to be controlled by fiber rupture properties, and compared favorably to those previously measured for state-of-the-art BN fiber coatings.
C1 Stevens Inst Technol, Dept Chem Biochem & Mat Engn, Hoboken, NJ 07030 USA.
NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
Ohio Aerosp Inst, Cleveland, OH 44135 USA.
RP Li, H (reprint author), Stevens Inst Technol, Dept Chem Biochem & Mat Engn, Hoboken, NJ 07030 USA.
NR 30
TC 10
Z9 13
U1 0
U2 6
PU AMER CERAMIC SOC
PI WESTERVILLE
PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43086-6136 USA
SN 0002-7820
J9 J AM CERAM SOC
JI J. Am. Ceram. Soc.
PD SEP
PY 2004
VL 87
IS 9
BP 1726
EP 1733
PG 8
WC Materials Science, Ceramics
SC Materials Science
GA 858LI
UT WOS:000224192900018
ER
PT J
AU Chatterjee, B
Noveron, JC
Resendiz, MJE
Liu, J
Yamamoto, T
Parker, D
Cinke, M
Nguyen, CV
Arif, AM
Stang, PJ
AF Chatterjee, B
Noveron, JC
Resendiz, MJE
Liu, J
Yamamoto, T
Parker, D
Cinke, M
Nguyen, CV
Arif, AM
Stang, PJ
TI Self-assembly of flexible supramolecular metallacyclic ensembles:
Structures and adsorption properties of their nanoporous crystalline
frameworks
SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
LA English
DT Article
ID LATTICE INCLUSION COMPLEXATION; TRIANGLE-SQUARE EQUILIBRIUM; FIT
MOLECULAR RECOGNITION; METAL-ORGANIC FRAMEWORKS; CAGE-LIKE COMPLEX;
X-RAY; RATIONAL DESIGN; GUEST-BINDING; COORDINATION NANOCAGE;
PD(II)-LINKED CAGES
AB The syntheses, structures, and N-2 adsorption properties of six new supramolecular metallacycles are reported. Flexible ditopic linkers, 1-4, with systematically varied lengths and conformational degrees of freedom were synthesized utilizing ester linkages. They were used in combination with (dppp)M(OTf)(2), where M = Pt(II) and Pd(II), and cis-(Me3P)(2)Pt(OTf)(2) to form flexible supramolecular metallacycles 5-10 in 88-98% isolated yields. Their structures were characterized via multinuclear NMR and X-ray crystallography. The metallacycles stack to form porous structures in the crystalline state. The pore dimensions depend on both the phosphorus ligands attached to the metals and the flexible linkers. Adsorption studies on the porous materials show that Sa, 6, 8, and 9 held 11.7, 16.5, 5.7, and 6.8 cm(3)/g STP of N-2 at 77 K, respectively. A guest-exchange study with nitromethane and toluene reveals that the nanopore in 5 is flexible, a property which was transferred from the linker to the supramolecular structure in the solid state.
C1 Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA.
Univ Texas, Dept Chem, El Paso, TX 79968 USA.
NASA, Ames Res Ctr, Eloret Corp, Moffett Field, CA 94035 USA.
RP Noveron, JC (reprint author), Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA.
EM jcnoveron@utep.edu; stang@chem.utah.edu
RI Yamamoto, Takuya/F-5697-2010
FU NIGMS NIH HHS [GM-57052, GM66504-01]
NR 70
TC 80
Z9 81
U1 2
U2 20
PU AMER CHEMICAL SOC
PI WASHINGTON
PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
SN 0002-7863
J9 J AM CHEM SOC
JI J. Am. Chem. Soc.
PD SEP 1
PY 2004
VL 126
IS 34
BP 10645
EP 10656
DI 10.1021/ja038819
PG 12
WC Chemistry, Multidisciplinary
SC Chemistry
GA 849RU
UT WOS:000223559100044
PM 15327323
ER
PT J
AU Kaul, AB
Bumble, B
Lee, KA
LeDuc, HG
Rice, F
Zmuidzinas, J
AF Kaul, AB
Bumble, B
Lee, KA
LeDuc, HG
Rice, F
Zmuidzinas, J
TI Fabrication of wide-IF 200-300 GHz
superconductor-insulator-superconductor mixers with suspended metal beam
leads formed on silicon-on-insulator
SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B
LA English
DT Article
ID JUNCTIONS; MEMBRANE
AB We report on a fabrication process that uses SOI substrates and micromachining techniques to form wide-IF SIS mixer devices that have suspended metal beam leads for rf grounding. The mixers are formed on thin 25 mum membranes of Si, and are designed to operate in the 200-300 GHz band. Potential applications are in tropospheric chemistry, where increased sensitivity detectors and wide-IF bandwidth receivers are desired. They will also be useful in astrophysics to monitor absorption lines for CO at 230 GHz to study distant, highly redshifted galaxies by reducing scan times. Aside from a description of the fabrication process, electrical measurements of these Nb/Al-AIN(x)/Nb trilayer devices will also be presented. Since device quality is sensitive to thermal excursions, the new beam lead process appears to be compatible with conventional SIS device fabrication technology. (C) 2004 American Vacuum Society.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
CALTECH, Dept Phys, Pasadena, CA 91125 USA.
RP Kaul, AB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM anu.kaul@jpl.nasa.gov
NR 17
TC 9
Z9 9
U1 0
U2 0
PU A V S AMER INST PHYSICS
PI MELVILLE
PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA
SN 1071-1023
J9 J VAC SCI TECHNOL B
JI J. Vac. Sci. Technol. B
PD SEP-OCT
PY 2004
VL 22
IS 5
BP 2417
EP 2422
DI 10.1116/1.1798831
PG 6
WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology;
Physics, Applied
SC Engineering; Science & Technology - Other Topics; Physics
GA 870HN
UT WOS:000225048300030
ER
PT J
AU Roth, DJ
Verrilli, MJ
Cosgriff, LM
Martin, RE
Bhatt, RT
AF Roth, DJ
Verrilli, MJ
Cosgriff, LM
Martin, RE
Bhatt, RT
TI Microstructural and discontinuity characterization in ceramic composites
using an ultrasonic guided wave scan system
SO MATERIALS EVALUATION
LA English
DT Article
DE composites; ceramics; ultrasonics; guided waves
AB In this study, an ultrasonic guided wave scan system was used to characterize various microstructural and discontinuity conditions in two types of ceramic matrix composites, SiC/SiC and C/SiC. Rather than attempting to isolate specific lamb wave modes to use for characterization (as is desired for many types of guided wave testing problems), the guided wave scan system utilizes the total (multimode) ultrasonic response in its test analysis. Several time and frequency domain parameters are calculated from the ultrasonic guided wave signal at each scan location to form images. Microstructural and discontinuity conditions examined include delamination, density variation, cracking and pre- and postinfiltration. Results are compared with thermographic imaging methods. Although the guided wave technique is commonly used so scanning can be eliminated, applying the technique in the scanning mode allows a more precise characterization of discontinuity conditions.
C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
Cleveland State Univ, Cleveland, OH 44115 USA.
USA, Res Lab, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP Roth, DJ (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,Mail Stop 6-1, Cleveland, OH 44135 USA.
EM donald.j.roth@nasa.gov
NR 11
TC 6
Z9 6
U1 0
U2 0
PU AMER SOC NONDESTRUCTIVE TEST
PI COLUMBUS
PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA
SN 0025-5327
J9 MATER EVAL
JI Mater. Eval.
PD SEP
PY 2004
VL 62
IS 9
BP 948
EP 953
PG 6
WC Materials Science, Characterization & Testing
SC Materials Science
GA 853PM
UT WOS:000223839500006
ER
PT J
AU Hull, PV
Canfield, SL
Carrington, C
AF Hull, PV
Canfield, SL
Carrington, C
TI A radient energy-powered shape memory alloy actuator
SO MECHATRONICS
LA English
DT Article
DE actuator; cylindrical concentrator; Maxwell's relation; radiant energy;
shape memory alloys; space
ID MODEL
AB This paper will present the development of an innovative actuator using a shape memory alloy (SMA) that is powered by available radiant energy in the space environment. Currently, self-contained or tethered power supplies provide the energy source for actuators in space applications. These can be costly, heavy and require regular maintenance and/or refueling. Ideally an actuator for space applications should have a high power density, be able to operate with little interference from its power source and maintain a low operating cost. Shape memory alloys are materials that recover internal strain with the addition of heat, thus changing thermal energy to mechanical energy. Because of this, they are known as thermomechanical motors. These materials can be thermally actuated by a number of means with the primary conventional approach based on resistive heating. Radiant energy, while typically impractical for use under normal circumstances, is a significant and abundant energy source in space and can be directed to control phase transition in a SMA material. This paper will describe the development of a radiant-heat driven SMA actuator, presenting a simple actuator model and prototype. The paper will also compare this actuator against other SMA-based actuators. (C) 2004 Elsevier Ltd. All rights reserved.
C1 Tennessee Technol Univ, Dept Mech Engn, Cookeville, TN 38501 USA.
NASA, George C Marshall Space Flight Ctr, Flight Projects Directorate, Huntsville, AL 35812 USA.
RP Canfield, SL (reprint author), Tennessee Technol Univ, Dept Mech Engn, Cookeville, TN 38501 USA.
EM scanfield@tntech.edu
NR 19
TC 7
Z9 7
U1 1
U2 2
PU PERGAMON-ELSEVIER SCIENCE LTD
PI OXFORD
PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND
SN 0957-4158
J9 MECHATRONICS
JI Mechatronics
PD SEP
PY 2004
VL 14
IS 7
BP 757
EP 775
DI 10.1016/j.mechatronics.2004.01.008
PG 19
WC Automation & Control Systems; Computer Science, Artificial Intelligence;
Engineering, Electrical & Electronic; Engineering, Mechanical
SC Automation & Control Systems; Computer Science; Engineering
GA 830SM
UT WOS:000222143400002
ER
PT J
AU Schulte, M
Shock, E
AF Schulte, M
Shock, E
TI Coupled organic synthesis and mineral alteration on meteorite parent
bodies
SO METEORITICS & PLANETARY SCIENCE
LA English
DT Article
ID CM CARBONACEOUS CHONDRITES; MOLAL THERMODYNAMIC PROPERTIES; CRETACEOUS
TERTIARY BOUNDARY; AQUEOUS ALTERATION; MURCHISON METEORITE; STONY
METEORITES; AMINO-ACIDS; METASTABLE EQUILIBRIUM; COMPUTER-SIMULATIONS;
HYDROTHERMAL SYSTEMS
AB The hypothesis that the soluble fraction of the organic compounds present in carbonaceous chondrite meteorites was formed during aqueous alteration of the parent body was tested with mass-transfer, reaction-path calculations. In these calculations, we start with likely compositions of the original parent body and asteroidal fluids that are far from thermodynamic equilibrium, and metastable and stable equilibrium constraints are imposed as the total Gibbs free energy of the parent body environment is minimized. The results of these calculations suggest that the classes of soluble organic compounds present in carbonaceous chondrite meteorites could have formed during relatively low temperature aqueous alteration of the meteorite parent body or bodies. The main controls on the potential for synthesis and transformation of organic compounds were the oxidation state of the rock/fluid system, the bulk composition of that system, and the temperatures that were achieved during the alteration event or events. It also appears that the alteration mineral assemblages were influenced by the presence of soluble organic compounds and reaction among them.
C1 NASA, Ames Res Ctr, Exobiol Branch, Moffett Field, CA 94035 USA.
Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA.
Arizona State Univ, Dept Chem & Biochem, Tempe, AZ 85287 USA.
RP Schulte, M (reprint author), NASA, Ames Res Ctr, Exobiol Branch, MS 239-4, Moffett Field, CA 94035 USA.
EM mitchell.schulte@nasa.gov
NR 94
TC 26
Z9 26
U1 0
U2 17
PU WILEY-BLACKWELL
PI MALDEN
PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA
SN 1086-9379
J9 METEORIT PLANET SCI
JI Meteorit. Planet. Sci.
PD SEP
PY 2004
VL 39
IS 9
BP 1577
EP 1590
PG 14
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 856MR
UT WOS:000224049800009
ER
PT J
AU Page, KL
Reeves, JN
O'Brien, PT
Turner, MJL
Worrall, DM
AF Page, KL
Reeves, JN
O'Brien, PT
Turner, MJL
Worrall, DM
TI XMM-Newton observations of high-luminosity radio-quiet quasi-stellar
objects
SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
LA English
DT Article
DE galaxies : active; X-rays : galaxies
ID X-RAY-SPECTRA; ACTIVE GALACTIC NUCLEI; COLD MATTER;
ENERGY-DISTRIBUTIONS; COMPTON REFLECTION; GRAVITATIONAL LENS; GINGA
OBSERVATIONS; SEYFERT-GALAXIES; ALPHA EMISSION; SKY SURVEY
AB XMM-Newton observations of five high-luminosity radio-quiet quasi-stellar objects (QSOs; Q 0144 3938, UM 269, PG 1634 + 706, SBS 0909 + 532 and PG 1247 + 267) are presented. Spectral energy distributions were calculated from the XMM-Newton European Photon Imaging Camera (EPIC) and Optical Monitor (OM) data, with bolometric luminosities estimated in the range from 7 x 10(45) to 2 x 10(48) erg s(-1) for the sample, peaking in the ultraviolet. At least four of the QSOs show a similar soft excess, which can be well modelled by either one or two blackbody components, in addition to the hard X-ray power law. The temperatures of these blackbodies (similar to100- 500 eV) are too high to be direct thermal emission from the accretion disc, so Comptonization is suggested. Two populations of Comptonizing electrons, with different temperatures, are needed to model the broad-band spectrum. The hotter of these produces what is seen as the hard X-ray power law, while the cooler (similar to0.25-0.5 keV) population models the spectral curvature at low energies. Only one of the QSOs shows evidence for an absorption component, while three of the five show neutral iron emission. Of these, PG 1247 + 267 seems to have a broad line (with an equivalent width of 250 eV), with a strong, associated reflection component (R similar to 2), measured out to 30 keV in the rest frame of the QSO. Finally, it is concluded that the X-ray continuum shape of active galactic nuclei remains essentially constant over a wide range of black hole mass and luminosity.
C1 Univ Leicester, Dept Phys & Astron, Xray & Observat Astron Grp, Leicester LE1 7RH, Leics, England.
NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England.
RP Page, KL (reprint author), Univ Leicester, Dept Phys & Astron, Xray & Observat Astron Grp, Leicester LE1 7RH, Leics, England.
EM kpa@star.le.ac.uk
NR 54
TC 29
Z9 29
U1 0
U2 0
PU BLACKWELL PUBLISHING LTD
PI OXFORD
PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND
SN 0035-8711
J9 MON NOT R ASTRON SOC
JI Mon. Not. Roy. Astron. Soc.
PD SEP 1
PY 2004
VL 353
IS 1
BP 133
EP 142
DI 10.1111/j.1365-2966.2004.08051.x
PG 10
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 847OJ
UT WOS:000223404500015
ER
PT J
AU Marshall, CH
Pielke, RA
Steyaert, LT
AF Marshall, CH
Pielke, RA
Steyaert, LT
TI Has the conversion of natural wetlands to agricultural land increased
the incidence and severity of damaging freezes in south Florida?
SO MONTHLY WEATHER REVIEW
LA English
DT Article
ID OSCILLATION; ATMOSPHERE; PATTERNS; WEATHER; FLUXES; CITRUS; MODELS;
SEASON
AB On several occasions, winter freezes have wrought severe destruction on Florida agriculture. A series of devastating freezes around the turn of the twentieth century, and again during the 1980s, were related to anomalies in the large-scale flow of the ocean-atmosphere system. During the twentieth century, substantial areas of wetlands in south Florida were drained and converted to agricultural land for winter fresh vegetable and sugarcane production. During this time, much of the citrus industry also was relocated to those areas to escape the risk of freeze farther to the north. The purpose of this paper is to present a modeling study designed to investigate whether the conversion of the wetlands to agriculture itself could have resulted in or exacerbated the severity of recent freezes in those agricultural areas of south Florida.
For three recent freeze events, a pair of simulations was undertaken with the Regional Atmospheric Modeling System. One member of each pair employed land surface properties that represent pre-1900s (near natural) land cover, whereas the other member of each pair employed data that represent near-current land-use patterns as derived from analysis of Landsat data valid for 1992/93. These two different land cover datasets capture well the conversion of wetlands to agriculture in south Florida during the twentieth century. Use of current land surface properties resulted in colder simulated minimum temperatures and temperatures that remained below freezing for a longer period at locations of key agricultural production centers in south Florida that were once natural wetlands. Examination of time series of the surface energy budget from one of the cases reveals that when natural land cover is used, a persistent moisture flux from the underlying wetlands during the nighttime hours served to prevent the development of below-freezing temperatures at those same locations. When the model results were subjected to an important sensitivity factor, the depth of standing water in the wetlands, the outcome remained consistent. These results provide another example of the potential for humans to perturb the climate system in ways that can have severe socioeconomic consequences by altering the land surface alone.
C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
US Geol Survey, EROS Data Ctr, Greenbelt, MD USA.
RP Marshall, CH (reprint author), NCEP Environm Ctr, 5200 Auth Rd,Rm 207, Camp Springs, MD 20746 USA.
EM Curtis.Marshall@noaa.gov
RI Pielke, Roger/A-5015-2009
NR 33
TC 19
Z9 19
U1 0
U2 4
PU AMER METEOROLOGICAL SOC
PI BOSTON
PA 45 BEACON ST, BOSTON, MA 02108-3693 USA
SN 0027-0644
J9 MON WEATHER REV
JI Mon. Weather Rev.
PD SEP
PY 2004
VL 132
IS 9
BP 2243
EP 2258
DI 10.1175/1520-0493(2004)132<2243:HTCONW>2.0.CO;2
PG 16
WC Meteorology & Atmospheric Sciences
SC Meteorology & Atmospheric Sciences
GA 850JA
UT WOS:000223606000006
ER
PT J
AU Gomez, G
Koon, WS
Lo, WS
Marsden, JE
Masdemont, J
Ross, SD
AF Gomez, G
Koon, WS
Lo, WS
Marsden, JE
Masdemont, J
Ross, SD
TI Connecting orbits and invariant manifolds in the spatial restricted
three-body problem
SO NONLINEARITY
LA English
DT Article
ID 3 BODY PROBLEM; COLLINEAR POINTS; HALO ORBITS; MISSION; FORMULATION;
RESONANCE; STABILITY; DYNAMICS; CAPTURE; DESIGN
AB The invariant manifold structures of the collinear libration points for the restricted three-body problem provide the framework for understanding transport phenomena from a geometrical point of view. In particular, the stable and unstable invariant manifold tubes associated with libration point orbits are the phase space conduits transporting material between primary bodies for separate three-body systems. These tubes can be used to construct new spacecraft trajectories, such as a 'Petit Grand Tour' of the moons of Jupiter. Previous work focused on the planar circular restricted three-body problem. This work extends the results to the three-dimensional case.
Besides providing a full description of different kinds of libration motions in a large vicinity of these points, this paper numerically demonstrates the existence of heteroclinic connections between pairs of libration orbits, one around the libration point L(1) and the other around L(2). Since these connections are asymptotic orbits, no manoeuvre is needed to perform the transfer from one libration point orbit to the other. A knowledge of these orbits can be very useful in the design of missions such as the Genesis Discovery Mission, and may provide the backbone for other interesting orbits in the future.
C1 CALTECH, Control & Dynam Syst, Pasadena, CA 91125 USA.
Univ Barcelona, Dept Matemat Aplicada & Anal, Barcelona, Spain.
CALTECH, Jet Prop Lab, Navigat & Mission Design, Pasadena, CA 91109 USA.
Univ Politecn Cataluna, Dept Matemat Aplicada I, Barcelona, Spain.
RP Gomez, G (reprint author), CALTECH, Control & Dynam Syst, MC 107-81, Pasadena, CA 91125 USA.
EM gerard@maia.ub.es; koon@cds.caltech.edu; martin.lo@jpl.nasa.gov;
marsden@cds.caltech.edu; josep@barquins.upc.es; shane@cds.caltech.edu
RI Ross, Shane/B-7237-2009
OI Ross, Shane/0000-0001-5523-2376
NR 43
TC 141
Z9 150
U1 0
U2 9
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0951-7715
J9 NONLINEARITY
JI Nonlinearity
PD SEP
PY 2004
VL 17
IS 5
BP 1571
EP 1606
AR PII S0951-7715(04)67794-2
DI 10.1088/0951-7715/17/5/02
PG 36
WC Mathematics, Applied; Physics, Mathematical
SC Mathematics; Physics
GA 861CX
UT WOS:000224394800002
ER
PT J
AU Moles, A
AF Moles, A
TI Parasites of juvenile yellowfin sole and rock sole in southeast Alaska
SO NORTHWEST SCIENCE
LA English
DT Article
ID BRITISH-COLUMBIA; BIOLOGICAL TAGS; INDICATORS; FISH
C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA.
RP Moles, A (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA.
EM Adam.Moles@noaa.gov
NR 17
TC 0
Z9 1
U1 0
U2 0
PU WASHINGTON STATE UNIV
PI PULLMAN
PA PO BOX 645020, PULLMAN, WA 99164-5910 USA
SN 0029-344X
J9 NORTHWEST SCI
JI Northwest Sci.
PD FAL
PY 2004
VL 78
IS 4
BP 339
EP 343
PG 5
WC Ecology
SC Environmental Sciences & Ecology
GA 897OG
UT WOS:000227013900009
ER
PT J
AU Adams, J
AF Adams, J
CA EUSO Consortium
TI The EUSO mission
SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS
LA English
DT Article; Proceedings Paper
CT 2nd International Conference on Particle and Fundamental Physics in
Space
CY DEC 10-12, 2003
CL Washington, DC
SP NASA
ID ENERGY COSMIC-RAYS; NEUTRINOS
AB The investigation of cosmic rays with energies in excess of 10(20) eV holds the potential for discoveries in astrophysics, cosmology and/or fundamental physics. This has motivated the construction of very large ground-based experiments and has lead to the development of the first space mission to measure these cosmic rays, the Extreme Universe Space Observatory (EUSO). EUSO will use the Earth's atmosphere viewed from space as a detector of extreme energy cosmic rays (EECRs). EUSO's collecting power will exceed the present experiments by more than a factor of 10 and extend the cosmic ray spectrum beyond 10(20) eV with high statistics.
C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA.
RP Adams, J (reprint author), NASA, George C Marshall Space Flight Ctr, Mail Code SD50, Huntsville, AL 35812 USA.
NR 24
TC 1
Z9 1
U1 0
U2 0
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0920-5632
J9 NUCL PHYS B-PROC SUP
JI Nucl. Phys. B-Proc. Suppl.
PD SEP
PY 2004
VL 134
BP 15
EP 22
DI 10.1016/j.nuclphysbps.2004.08.002
PG 8
WC Physics, Particles & Fields
SC Physics
GA 873MI
UT WOS:000225284000003
ER
PT J
AU Mitchell, JW
Abe, K
Anraku, K
Fuke, H
Haino, S
Hams, T
Imori, M
Itazaki, A
Izumi, K
Kumazawa, T
Lee, MH
Maeno, T
Makida, Y
Matsuda, S
Matsumoto, H
Matsumoto, K
Moiseev, A
Myers, ZD
Nishimura, J
Nozaki, M
Omiya, H
Orito, S
Ormes, JF
Sanuki, T
Sasaki, M
Seo, ES
Shikaze, Y
Streitmatter, RE
Suzuki, J
Takasugi, Y
Tanaka, K
Tanizaki, K
Yamagami, T
Yamamoto, A
Yamamoto, Y
Yamato, K
Yoshida, T
Yoshimura, K
AF Mitchell, JW
Abe, K
Anraku, K
Fuke, H
Haino, S
Hams, T
Imori, M
Itazaki, A
Izumi, K
Kumazawa, T
Lee, MH
Maeno, T
Makida, Y
Matsuda, S
Matsumoto, H
Matsumoto, K
Moiseev, A
Myers, ZD
Nishimura, J
Nozaki, M
Omiya, H
Orito, S
Ormes, JF
Sanuki, T
Sasaki, M
Seo, ES
Shikaze, Y
Streitmatter, RE
Suzuki, J
Takasugi, Y
Tanaka, K
Tanizaki, K
Yamagami, T
Yamamoto, A
Yamamoto, Y
Yamato, K
Yoshida, T
Yoshimura, K
TI The BESS Program
SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS
LA English
DT Article; Proceedings Paper
CT 2nd International Conference on Particle and Fundamental Physics in
Space
CY DEC 10-12, 2003
CL Washington, DC
SP NASA
ID COSMIC-RAY ANTIPROTON; SUPERSYMMETRIC DARK-MATTER; PRIMORDIAL
BLACK-HOLES; SOLAR MINIMUM; ONBOARD BESS; FLUX; SPECTROMETER;
ANTIHELIUM; SPECTRUM; HELIUM
AB In nine flights between 1993 and 2002, the Balloon Borne Experiment with a Superconducting Spectrometer (BESS) has measured the energy spectrum of cosmic-ray antiprotons between 0.18 and 4.20 GeV, and the spectra of protons and helium to several hundred GeV. BESS has also placed stringent upper limits on the existence of antihelium and antiduterons. Above about 1 GeV, models in which antiprotons are secondary products of the interactions of primary cosmic rays with the ISM agree with the BESS spectrum. Below I GeV, BESS data suggest the presence of an additional source of antiprotons. The antiproton/proton ratios measured between 1993 and 1999, during the Sun's positive-polarity phase, are consistent with simple models of solar modulation. Results from the 2000 flight, following the solar magnetic field reversal, show a sudden increase in the antiproton/proton ratio and tend to favor a charge-sign-dependent drift model. To extend BESS measurements to lower energies, a new instrument, BESS-Polar, is under construction for a flight from Antarctica in 2004.
C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
High Energy Accelerator Res Org, KEK, Tsukuba, Ibaraki 3050801, Japan.
Univ Tokyo, Tokyo 1130033, Japan.
Kobe Univ, Kobe, Hyogo 6578501, Japan.
Univ Maryland, College Pk, MD 20742 USA.
ISAS, JAXA, Sagamihara, Kanagawa 2298510, Japan.
RP Orito, S (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
OI Seo, Eun-Suk/0000-0001-8682-805X
NR 65
TC 14
Z9 14
U1 0
U2 1
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0920-5632
J9 NUCL PHYS B-PROC SUP
JI Nucl. Phys. B-Proc. Suppl.
PD SEP
PY 2004
VL 134
BP 31
EP 38
DI 10.1016/j.nuclphysbps.2004.08.003
PG 8
WC Physics, Particles & Fields
SC Physics
GA 873MI
UT WOS:000225284000005
ER
PT J
AU Boezio, M
Bonvicini, V
Mocchiutti, E
Schiavon, P
Vacchi, A
Zampa, G
Zampa, N
Bakaldin, A
Galper, AM
Koldashov, SV
Korotkov, MG
Mikhailov, VV
Voronov, SA
Yurkin, Y
Basili, A
Bencardino, R
Bongiorno, L
Casolino, M
De Pascale, MP
Furano, G
Menicucci, A
Minori, M
Morselli, A
Picozza, P
Sparvoli, R
Wischnewski, R
Adriani, O
Bonechi, L
Bongi, M
Giambi, F
Papini, P
Ricciarini, SB
Spillantini, P
Straulino, S
Taccetti, F
Vannuccini, E
Castellini, G
Carlson, P
Lund, J
Lundquist, J
Orsi, S
Pearce, M
Barbarino, GC
Campana, D
Osteria, G
Rossi, G
Russo, S
Boscherini, M
Menn, W
Simon, M
Ricci, M
Ambriola, M
Bellotti, R
Cafagna, F
Circella, M
De Marzo, C
Giglietto, N
Mirizzi, N
Romita, M
Spinelli, P
Bogomolov, E
Krutkov, S
Vasiljev, G
Bazilevskaja, G
Grigorjeva, A
Mukhametshin, R
Stozhkov, Y
Mitchell, JW
Streitmatter, RE
Stochaj, SJ
AF Boezio, M
Bonvicini, V
Mocchiutti, E
Schiavon, P
Vacchi, A
Zampa, G
Zampa, N
Bakaldin, A
Galper, AM
Koldashov, SV
Korotkov, MG
Mikhailov, VV
Voronov, SA
Yurkin, Y
Basili, A
Bencardino, R
Bongiorno, L
Casolino, M
De Pascale, MP
Furano, G
Menicucci, A
Minori, M
Morselli, A
Picozza, P
Sparvoli, R
Wischnewski, R
Adriani, O
Bonechi, L
Bongi, M
Giambi, F
Papini, P
Ricciarini, SB
Spillantini, P
Straulino, S
Taccetti, F
Vannuccini, E
Castellini, G
Carlson, P
Lund, J
Lundquist, J
Orsi, S
Pearce, M
Barbarino, GC
Campana, D
Osteria, G
Rossi, G
Russo, S
Boscherini, M
Menn, W
Simon, M
Ricci, M
Ambriola, M
Bellotti, R
Cafagna, F
Circella, M
De Marzo, C
Giglietto, N
Mirizzi, N
Romita, M
Spinelli, P
Bogomolov, E
Krutkov, S
Vasiljev, G
Bazilevskaja, G
Grigorjeva, A
Mukhametshin, R
Stozhkov, Y
Mitchell, JW
Streitmatter, RE
Stochaj, SJ
TI The space experiment PAMELA
SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS
LA English
DT Article; Proceedings Paper
CT 2nd International Conference on Particle and Fundamental Physics in
Space
CY DEC 10-12, 2003
CL Washington, DC
SP NASA
ID COSMIC-RAY ELECTRONS; SOLAR MINIMUM ACTIVITY; MAGNETIC SPECTROMETER;
IMAGING CALORIMETER; ANTIPROTON SPECTRUM; POSITRONS; FLUX; RADIATION;
RATIO; ORBIT
AB We present in this paper a status report of the space experiment PAMELA. PAMELA is a satellite-borne experiment which primarily aims to measure the antiproton and positron spectra in the cosmic radiation over a large energy range (from 80 MeV up to 190 GeV for antiprotons and from 50 MeV up to 270 GeV for positrons) and to search for antinuclei with a sensitivity of the order of 10(-8) in the antihelium/ helium ratio. In addition, it will measure the light nucleax component of cosmic rays and investigate phenomena connected with Solar and Earth physics. The apparatus will be installed onboard the polar orbiting Resurs DK1 satellite, which will be launched into space by a Soyuz TM2 rocket in 2004 from Baikonur cosmodrome in Kazakhstan, for a 3 year long mission. PAMELA consists of: a time of flight system, a transition radiation detector, a magnetic spectrometer, an anticoincidence detector, an electromagnetic imaging calorimeter, a shower tail catcher scintillator and a neutron detector.
C1 Univ Trieste, Ist Nazl Fis Nucl, Trieste, Italy.
Univ Trieste, Dept Phys, Trieste, Italy.
Moscow Engn & Phys Inst, Moscow, Russia.
Univ Roma Tor Vergata, Ist Nazl Fis Nucl, Rome, Italy.
Univ Roma Tor Vergata, Dept Phys, Rome, Italy.
Univ Florence, Dept Phys, Florence, Italy.
Univ Florence, Ist Nazl Fis Nucl, Florence, Italy.
Royal Inst Technol, KTH, Stockholm, Sweden.
Univ Naples Federico II, Dept Phys, Naples, Italy.
Univ Naples Federico II, Ist Nazl Fis Nucl, Naples, Italy.
Univ Siegen, D-5900 Siegen, Germany.
Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy.
Univ Bari, Dept Phys, Bari, Italy.
Univ Bari, Ist Nazl Fis Nucl, Bari, Italy.
AF Ioffe Phys Tech Inst, St Petersburg, Russia.
PN Lebedev Phys Inst, Moscow 117924, Russia.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
New Mexico State Univ, Las Cruces, NM 88003 USA.
RP Boezio, M (reprint author), Univ Trieste, Ist Nazl Fis Nucl, Trieste, Italy.
RI Krutkov, Sergey/E-7561-2014; Vacchi, Andrea/C-1291-2010; Barbarino,
Giancarlo/L-2559-2015; Morselli, Aldo/G-6769-2011; giglietto,
nicola/I-8951-2012; Cafagna, Francesco/A-9299-2010; Mocchiutti,
Emiliano/I-8049-2013; Mikhailov, Vladimir/B-5368-2014; Vasilyev,
Gennady/E-4843-2014; Bongi, Massimo/L-9417-2015; Galper,
Arkady/M-9610-2015; Voronov, Sergey/P-9654-2016
OI Papini, Paolo/0000-0003-4718-2895; Boezio, Mirko/0000-0002-8015-2981;
Taccetti, Francesco/0000-0003-2657-2990; Bellotti,
Roberto/0000-0003-3198-2708; casolino, marco/0000-0001-6067-5104;
Ricciarini, Sergio Bruno/0000-0001-6176-3368; SPINELLI,
Paolo/0000-0001-6688-8864; Castellini, Guido/0000-0002-0177-0643;
Sparvoli, Roberta/0000-0002-6314-6117; Picozza,
Piergiorgio/0000-0002-7986-3321; Vacchi, Andrea/0000-0003-3855-5856;
Barbarino, Giancarlo/0000-0001-9253-3397; Morselli,
Aldo/0000-0002-7704-9553; giglietto, nicola/0000-0002-9021-2888;
Cafagna, Francesco/0000-0002-7450-4784; Mocchiutti,
Emiliano/0000-0001-7856-551X; Mikhailov, Vladimir/0000-0003-3851-2901;
Bongi, Massimo/0000-0002-6050-1937; Voronov, Sergey/0000-0002-9209-0618
NR 35
TC 26
Z9 26
U1 2
U2 6
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0920-5632
J9 NUCL PHYS B-PROC SUP
JI Nucl. Phys. B-Proc. Suppl.
PD SEP
PY 2004
VL 134
BP 39
EP 46
DI 10.1016/j.nuclphysbps.2004.08.006
PG 8
WC Physics, Particles & Fields
SC Physics
GA 873MI
UT WOS:000225284000006
ER
PT J
AU Prestage, JD
Maleki, L
AF Prestage, JD
Maleki, L
TI Precision clocks in space and alpha-variations
SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS
LA English
DT Article; Proceedings Paper
CT 2nd International Conference on Particle and Fundamental Physics in
Space
CY DEC 10-12, 2003
CL Washington, DC
SP NASA
ID FINE-STRUCTURE CONSTANT
AB Important developments both in theoretical and observational cosmology have fueled considerable interest in searches for variations of the fine structure constant. Experimentally, Webb et al have found evidence for a cosmological variation of the fine structure constant through an analysis of the absorption fines in galactic halos from quasar-emitted fight. Recently developed small ion atomic clocks enable Solar System tests for equivalence principle (EP) violating alpha-variations by way of rate-comparisons of three ultra-stable atomic clocks near-to and far-from the sun where gravitational red-shift changes are more than 10(4) larger than in low Earth orbit. No space tests of the EP have been made in nearly 30 years, since the GP-A hydrogen maser reached a 10,000 km apogee confirming EP red-shift predictions to similar to1 part in 10(4). Today's small ion clocks, nearly 100x more stable and 100x smaller than the GP-A H-maser, could probe for EP violating scalar fields near the sun for mission costs comparable to low Earth orbiters and improve the GPA sensitivity by 5 to 6 orders of magnitude.
C1 CALTECH, Jet Prop Lab, Quantum Sci & Technol Grp, Pasadena, CA 91109 USA.
RP Prestage, JD (reprint author), CALTECH, Jet Prop Lab, Quantum Sci & Technol Grp, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
NR 18
TC 2
Z9 2
U1 1
U2 1
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0920-5632
J9 NUCL PHYS B-PROC SUP
JI Nucl. Phys. B-Proc. Suppl.
PD SEP
PY 2004
VL 134
BP 163
EP 170
DI 10.1016/j.nuclphysbps.2004.08.026
PG 8
WC Physics, Particles & Fields
SC Physics
GA 873MI
UT WOS:000225284000027
ER
PT J
AU Turyshev, SG
Shao, M
Nordtvedt, KL
AF Turyshev, SG
Shao, M
Nordtvedt, KL
TI The laser astrometric test of relativity mission
SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS
LA English
DT Article; Proceedings Paper
CT 2nd International Conference on Particle and Fundamental Physics in
Space
CY DEC 10-12, 2003
CL Washington, DC
SP NASA
ID POST-NEWTONIAN FORMALISM; GENERAL-RELATIVITY; 2ND-ORDER CONTRIBUTIONS;
GRAVITY
AB This paper discusses new fundamental physics experiment to test relativistic gravity at the accuracy better than the effects of the 2nd order in the gravitational field strength, proportional to G(2). The Laser Astrometric Test of Relativity (LATOR) mission uses laser interferometry between two micro-spacecraft whose lines of sight pass close by the Sun to accurately measure deflection of light in the solar gravity. The key element of the experimental design is a redundant geometry optical truss provided by a long-baseline (100 m) multi-channel stellar optical interferometer placed on the International Space Station (ISS). The interferometer is used for measuring the angles between the two spacecraft. In Euclidean geometry, determination of a triangle's three sides determines any angle therein; with gravity changing the optical lengths of sides passing close by the Sun and deflecting the light, the Euclidean relationships are overthrown. The geometric redundancy enables LATOR to measure the departure from Euclidean geometry caused by the solar gravity field to a very high accuracy. LATOR will not only improve the value of the parameterized post-Newtonian (PPN) parameter gamma to unprecedented levels of accuracy of 10(-8), it will also reach ability to measure effects of the next post-Newtonian order (C-4) of light deflection resulting from gravity's intrinsic non-linearity. The solar quadrupole moment parameter, J(2), will be measured with high precision, as well as a variety of other relativistic effects including Lense-Thirring precession. LATOR will lead to very robust advances in the tests of fundamental physics: this mission could discover a violation or extension of general relativity, or reveal the presence of an additional long range interaction in the physical law. There are no analogs to the LATOR experiment; it is unique and is a natural culmination of solar system gravity experiments.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
NW Anal, Bozeman, MT 59715 USA.
RP Turyshev, SG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
NR 29
TC 3
Z9 3
U1 0
U2 0
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0920-5632
EI 1873-3832
J9 NUCL PHYS B-PROC SUP
JI Nucl. Phys. B-Proc. Suppl.
PD SEP
PY 2004
VL 134
BP 171
EP 178
DI 10.1016/j.nuclphysbps.2004.08.027
PG 8
WC Physics, Particles & Fields
SC Physics
GA 873MI
UT WOS:000225284000028
ER
PT J
AU Penanen, K
Chui, T
AF Penanen, K
Chui, T
TI A novel two-step laser ranging technique for a precision test of the
theory of gravity
SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS
LA English
DT Article; Proceedings Paper
CT 2nd International Conference on Particle and Fundamental Physics in
Space
CY DEC 10-12, 2003
CL Washington, DC
SP NASA
AB All powered spacecraft experience residual systematic acceleration due to anisotropy of the thermal radiation pressure and fuel leakage. The residual acceleration limits the accuracy of any test of gravity that relies on the precise determination of the spacecraft trajectory. We describe a novel two-step laser ranging technique, which largely eliminates the effects of non-gravity acceleration sources and enables celestial mechanics checks with unprecedented precision. A passive proof mass is released from the mother spacecraft on a solar system exploration mission. Retro-reflectors attached to the proof mass allow its relative position to the spacecraft to be determined using optical ranging techniques. Meanwhile, the position of the spacecraft relative to the Earth is determined by ranging with a laser transponder. The vector sum of the two is the position, relative to the Earth, of the proof mass, the measurement of which is not affected by the residual accelerations of the mother spacecraft. We also describe the mission concept of the Dark Matter Explorers (DMX), which will demonstrate this technology and will use it to test the hypothesis that dark matter congregates around the sun. This hypothesis implies a small apparent deviation from the inverse square law of gravity, which can be detected by a sensitive experiment. We expect to achieve an acceleration resolution of similar to 10(-14)m/s(2). DMX will also be sensitive to acceleration towards the galactic center, which has a value of similar to 10(-10)m/s(2). Since dark matter dominates the galactic acceleration, DMX can also test whether dark matter obeys the equivalence principle to a level of 100 ppm by ranging to several proof masses of different composition from the mother spacecraft.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Chui, T (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Talso.C.Chui@jpl.nasa.gov
NR 5
TC 4
Z9 4
U1 0
U2 0
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0920-5632
J9 NUCL PHYS B-PROC SUP
JI Nucl. Phys. B-Proc. Suppl.
PD SEP
PY 2004
VL 134
BP 211
EP 213
DI 10.1016/j.nuclphysbps.2004.08.033
PG 3
WC Physics, Particles & Fields
SC Physics
GA 873MI
UT WOS:000225284000034
ER
PT J
AU Chui, T
Penanen, K
Barmatz, M
AF Chui, T
Penanen, K
Barmatz, M
TI High-resolution displacement sensor using SQUID array amplifier
SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS
LA English
DT Article; Proceedings Paper
CT 2nd International Conference on Particle and Fundamental Physics in
Space
CY DEC 10-12, 2003
CL Washington, DC
SP NASA
AB The recently developed SQUID array amplifier offers low noise amplification at a bandwidth that exceeds 5MHz. In this paper we present the design of a new displacement sensor, which makes use of a resonant amplification technique to convert the wide bandwidth into a substantially higher displacement resolution.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
RP Chui, T (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Talso.C.Chui@jpl.nasa.gov
NR 3
TC 1
Z9 1
U1 0
U2 0
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0920-5632
J9 NUCL PHYS B-PROC SUP
JI Nucl. Phys. B-Proc. Suppl.
PD SEP
PY 2004
VL 134
BP 214
EP 216
DI 10.1016/j.nuclphysbps.2004.08.035
PG 3
WC Physics, Particles & Fields
SC Physics
GA 873MI
UT WOS:000225284000035
ER
PT J
AU Barnes, NP
AF Barnes, NP
TI Compositionally tuned lasers for remote sensing
SO OPTICAL MATERIALS
LA English
DT Article; Proceedings Paper
CT 3rd International Symposium on Lasers and Nonlinear Optical Materials
CY JUL 20-23, 2003
CL Keystone, CO
AB NASA needs lasers that are capable of generating a specific preselected wavelength, have a small but useful tuning range, and are highly efficient. NASA Langley responded to this need by developing 2 compositionally tuned Nd laser materials that operate at a preselected wavelength, 0.94411 mum in this case. Although Nd:YAG was known to operate at 0.946 mum, it could not be tuned to 0.944 mum. In addition, the efficiency of Nd:YAG flash lamp pumped lasers operating at this wavelength was low. NASA Langley overcame these problems by analyzing and then utilizing nonstoichiometric garnet laser materials to compositionally tune the laser wavelength and a laser design to increase the efficiency. Implementing these ideas led to 2 compositionally tuned laser materials that operate at 0.94411 mum and a diode pumped, 0.946 mum Nd:YAG laser that operates in the TEM00 mode with a normal mode, optical to optical slope efficiency of 0.28. (C) 2004 Elsevier B.V. All rights reserved.
C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA.
RP Barnes, NP (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA.
EM norman.p.barnes@nasa.gov
NR 1
TC 1
Z9 1
U1 0
U2 0
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0925-3467
J9 OPT MATER
JI Opt. Mater.
PD SEP
PY 2004
VL 26
IS 4
BP 333
EP 336
DI 10.1016/j.optmat.2003.08.013
PG 4
WC Materials Science, Multidisciplinary; Optics
SC Materials Science; Optics
GA 856LM
UT WOS:000224046700002
ER
PT J
AU Bauschlicher, CW
Ricca, A
AF Bauschlicher, CW
Ricca, A
TI Binding of NH3 to graphite and to a (9,0) carbon nanotube
SO PHYSICAL REVIEW B
LA English
DT Article
ID DENSITY-FUNCTIONAL THEORY; WALLED CARBON NANOTUBES; GAUSSIAN-BASIS SETS;
ELECTRON CORRELATION; OXYGEN-ADSORPTION; WAVE-FUNCTIONS; HE-2;
MOLECULES; HYDROGEN; ENERGIES
AB The interaction of NH3 with graphite and a (9,0) carbon nanotube is studied using the second-order Moller-Plesset and density functional theory approaches. For both graphite and the nanotube, our best estimate of the NH3 binding energy is 2+/-2 kcal/mol. NH3 physisorbs on the carbon surface and the hydrogen end points toward the carbon surface. The binding is mostly electrostatic in nature and there is very little charge transfer occurring. Band-structure calculations on a (10,0) semiconducting nanotube show essentially no change in the nanotube band gap when NH3 is added. The implications of these calculations on the experimental results are discussed.
C1 NASA, Ames Res Ctr, Ames Ctr Nanotechnol, Moffett Field, CA 94035 USA.
RP Bauschlicher, CW (reprint author), NASA, Ames Res Ctr, Ames Ctr Nanotechnol, Mail Stop 230-3, Moffett Field, CA 94035 USA.
NR 37
TC 67
Z9 67
U1 0
U2 6
PU AMERICAN PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 1098-0121
J9 PHYS REV B
JI Phys. Rev. B
PD SEP
PY 2004
VL 70
IS 11
AR 115409
DI 10.1103/PhysRevB.70.115409
PG 6
WC Physics, Condensed Matter
SC Physics
GA 858RN
UT WOS:000224209500093
ER
PT J
AU Cummings, A
Osman, M
Srivastava, D
Menon, M
AF Cummings, A
Osman, M
Srivastava, D
Menon, M
TI Thermal conductivity of Y-junction carbon nanotubes
SO PHYSICAL REVIEW B
LA English
DT Article
ID MICROTUBULES; TRANSPORT; DEVICES
AB The thermal conductivity of a Y-junction carbon nanotube with a (14,0) trunk splitting into two (7,0) branches has been investigated using a molecular dynamics approach. It has been found that the thermal conductivity of the Y-junction nanotube is less than that of a corresponding straight (14,0) nanotube, due to lattice defects in the form of nonhexagonal carbon rings at the junction. These lattice defects result in a discontinuity in the temperature profile of the Y-junction nanotube. Defects that were introduced to a straight (14,0) nanotube resulted in a similar discontinuity in the temperature profile.
C1 Washington State Univ, Sch Elect Engn & Comp Sci, Pullman, WA 99164 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA.
Univ Kentucky, Ctr Computat Sci, Lexington, KY 40506 USA.
RP Cummings, A (reprint author), Washington State Univ, Sch Elect Engn & Comp Sci, Pullman, WA 99164 USA.
EM acumming@eecs.wsu.edu; osman@eecs.wsu.edu
RI Cummings, Aron/A-1426-2014
OI Cummings, Aron/0000-0003-2307-497X
NR 20
TC 44
Z9 44
U1 0
U2 7
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 1098-0121
EI 1550-235X
J9 PHYS REV B
JI Phys. Rev. B
PD SEP
PY 2004
VL 70
IS 11
AR 115405
DI 10.1103/PhysRevB.70.115405
PG 6
WC Physics, Condensed Matter
SC Physics
GA 858RN
UT WOS:000224209500089
ER
PT J
AU Lee, S
Lazarenkova, OL
von Allmen, P
Oyafuso, F
Klimeck, G
AF Lee, S
Lazarenkova, OL
von Allmen, P
Oyafuso, F
Klimeck, G
TI Effect of wetting layers on the strain and electronic structure of InAs
self-assembled quantum dots
SO PHYSICAL REVIEW B
LA English
DT Article
ID OPTICAL PHONONS; GAAS; SEMICONDUCTORS; SIMULATIONS; DEPENDENCE; ISLANDS;
GROWTH; BAND
AB The effect of wetting layers on the strain and electronic structure of InAs self-assembled quantum dots grown on GaAs is investigated with an atomistic valence-force-field model and an empirical tight-binding model. By comparing a dot with and without a wetting layer, we find that the inclusion of the wetting layer weakens the strain inside the dot by only 1% relative change, while it reduces the energy gap between a confined electron and hole level by as much as 10%. The small change in the strain distribution indicates that strain relaxes only little through the thin wetting layer. The large reduction of the energy gap is attributed to the increase of the confining-potential width rather than the change of the potential height. First-order perturbation calculations or, alternatively, the addition of an InAs disk below the quantum dot confirm this conclusion. The effect of the wetting layer on the wave function is qualitatively different for the weakly confined electron state and the strongly confined hole state. The electron wave function shifts from the buffer to the wetting layer, while the hole shifts from the dot to the wetting layer.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Purdue Univ, Sch Elect & Comp Engn, Network Computat Nantechnol, W Lafayette, IN 47906 USA.
RP Lee, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM Seungwon.Lee@jpl.nasa.gov
RI Klimeck, Gerhard/A-1414-2012
OI Klimeck, Gerhard/0000-0001-7128-773X
NR 33
TC 54
Z9 54
U1 1
U2 8
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 1098-0121
EI 1550-235X
J9 PHYS REV B
JI Phys. Rev. B
PD SEP
PY 2004
VL 70
IS 12
AR 125307
DI 10.1103/PhysRevB.70.125307
PG 7
WC Physics, Condensed Matter
SC Physics
GA 858RO
UT WOS:000224209600046
ER
PT J
AU Li, J
Ning, CZ
AF Li, J
Ning, CZ
TI Effects of electron-electron and electron-phonon scatterings on the
linewidths of intersubband transitions in a quantum well
SO PHYSICAL REVIEW B
LA English
DT Article
ID MANY-BODY; ABSORPTION LINEWIDTH; INTERFACE ROUGHNESS; OPTICAL-SPECTRA;
BLOCH EQUATIONS; DEPENDENCE; GAAS; COHERENCE; COULOMB; FIELD
AB We study the effects of electron-electron and electron-longitudinal optical (LO) phonon scatterings on the spectral lineshape and linewidth of intersubband transitions (ISBTs) within the second Born approximation. In particular, we show that there is a strong cancellation of the contributions from the so-called diagonal and nondiagonal scattering terms in the ISBT polarization equation to the linewidth. The omission of the nondiagonal scattering leads to a significant overestimate of the ISBT linewidth by several times for GaAs quantum wells. Such cancellation effect is less significant for semiconductors with strong nonparabolicity because of the dominance of the inhomogeneous broadening due to k-dependent transitions. In addition, there is a cancellation effect between the electron-electron and electron-phonon scatterings, leading to a property of nonadditiveness of contributions from individual scattering processes to the linewidth. Finally, we compare our theoretical linewidth calculation with existing experimental measurements and very good agreement is achieved.
C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Li, J (reprint author), NASA, Ames Res Ctr, M-S N229-1, Moffett Field, CA 94035 USA.
EM jnli@arc.nasa.gov; cning@mail.arc.nasa.gov
RI Ning, C. Z./D-4699-2009
OI Ning, C. Z./0000-0003-4583-8889
NR 33
TC 27
Z9 27
U1 0
U2 5
PU AMERICAN PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 1098-0121
J9 PHYS REV B
JI Phys. Rev. B
PD SEP
PY 2004
VL 70
IS 12
AR 125309
DI 10.1103/PhysRevB.70.125309
PG 8
WC Physics, Condensed Matter
SC Physics
GA 858RO
UT WOS:000224209600048
ER
PT J
AU Menon, M
Srivastava, D
Ponomareva, I
Chernozatonskii, LA
AF Menon, M
Srivastava, D
Ponomareva, I
Chernozatonskii, LA
TI Nanomechanics of silicon nanowires
SO PHYSICAL REVIEW B
LA English
DT Article
ID LASER-ABLATION; CARBON NANOTUBES; SI NANOWIRES; MICROSCOPY; SIMULATION;
ORDER
AB The stability and elasto-mechanical properties of tetragonal and cagelike or clathrate nanowires of Si are investigated and compared using molecular dynamics simulations. Our results show that cagelike nanowires, while possessing lesser density, are able to maintain their structural integrity over a larger range of strain conditions than the tetrahedral nanowires, making them a better candidate for structural strength, chemical sensor, and electronics applications under strain conditions. This could have important technological implications.
C1 Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA.
Univ Kentucky, Ctr Computat Sci, Lexington, KY 40506 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Russian Acad Sci, Inst Biochem Phys, Moscow 119991, Russia.
RP Menon, M (reprint author), Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA.
EM super250@pop.uky.edu; deepak@nas.nasa.gov; iponomar@sky.chph.ras.ru;
cherno@sky.chph.ras.ru
RI Ponomareva, Inna/C-4067-2012
NR 22
TC 66
Z9 68
U1 0
U2 15
PU AMERICAN PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 1098-0121
J9 PHYS REV B
JI Phys. Rev. B
PD SEP
PY 2004
VL 70
IS 12
AR 125313
DI 10.1103/PhysRevB.70.125313
PG 6
WC Physics, Condensed Matter
SC Physics
GA 858RO
UT WOS:000224209600052
ER
PT J
AU Noya, EG
Srivastava, D
Chernozatonskii, LA
Menon, M
AF Noya, EG
Srivastava, D
Chernozatonskii, LA
Menon, M
TI Thermal conductivity of carbon nanotube peapods
SO PHYSICAL REVIEW B
LA English
DT Article
ID ENCAPSULATED C-60
AB Thermal conductivity of a (10,10) carbon nanotube filled with C-60 fullerenes (or a peapod) is computed using direct molecular-dynamics simulations with the Tersoff-Brenner potential for C-C bonding interactions and the van der Waals potential for nonbonding interactions. The temperature-dependent thermal conductivity of the peapod, while showing qualitatively similar behavior to that of an unfilled carbon nanotube, is found to be higher than the nanotube at all temperatures. This is in agreement with recent experimental observations. The increase in thermal conductivity in the peapod is explained through (a) an energy transfer between fullerenes and nanotube due to low-frequency radial vibration coupling between fullerenes and nanotube, and (b) energy transfer along the peapod axis due to fullerene-fullerene collisions.
C1 Univ Santiago de Compostela, Fac Fis, Dept Fis Mat Condensada, E-15782 Santiago De Compostela, Spain.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
Russian Acad Sci, Inst Biochem Phys, Moscow 117977, Russia.
Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA.
Univ Kentucky, Ctr Computat Sci, Lexington, KY 40506 USA.
RP Noya, EG (reprint author), Univ Santiago de Compostela, Fac Fis, Dept Fis Mat Condensada, E-15782 Santiago De Compostela, Spain.
EM faevagn@usc.es; deepak@nas.nasa.gov; cherno@sky.chph.ras.ru;
madhu@ccs.uky.edu
RI Noya, Eva/F-4958-2010
OI Noya, Eva/0000-0002-6359-1026
NR 19
TC 40
Z9 44
U1 0
U2 10
PU AMERICAN PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 1098-0121
J9 PHYS REV B
JI Phys. Rev. B
PD SEP
PY 2004
VL 70
IS 11
AR 115416
DI 10.1103/PhysRevB.70.115416
PG 5
WC Physics, Condensed Matter
SC Physics
GA 858RN
UT WOS:000224209500100
ER
PT J
AU He, GW
Zhang, ZF
AF He, GW
Zhang, ZF
TI Two-point closure strategy in the mapping closure approximation approach
SO PHYSICAL REVIEW E
LA English
DT Article
ID GRID-GENERATED TURBULENCE; TEMPERATURE-FLUCTUATIONS; PASSIVE SCALAR;
REACTIVE FLOWS; MODEL; DECAY; RELAXATION; STATISTICS; FIELD
AB A two-point closure strategy in mapping closure approximation (MCA) approach is developed for the evolution of the probability density function (PDF) of a scalar advected by stochastic velocity fields. The MCA approach is based on multipoint statistics. We formulate a MCA modeled system using the one-point PDFs and two-point correlations. The MCA models can describe both the evolution of the PDF shape and the rate at which the PDF evolves.
C1 Chinese Acad Sci, Inst Mech, Lab Nonlinear Mech, Beijing 100080, Peoples R China.
NASA, Ctr Turbulence Res, Ames Res Ctr, Moffett Field, CA 94035 USA.
Stanford Univ, Moffett Field, CA 94035 USA.
RP Chinese Acad Sci, Inst Mech, Lab Nonlinear Mech, Beijing 100080, Peoples R China.
EM ghe@ctr.stanford.edu
NR 25
TC 6
Z9 6
U1 0
U2 3
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 2470-0045
EI 2470-0053
J9 PHYS REV E
JI Phys. Rev. E
PD SEP
PY 2004
VL 70
IS 3
AR 036309
DI 10.1103/PhysRevE.70.036309
PN 2
PG 4
WC Physics, Fluids & Plasmas; Physics, Mathematical
SC Physics
GA 859XS
UT WOS:000224302300071
PM 15524635
ER
PT J
AU Rame, E
Garoff, S
Willson, KR
AF Rame, E
Garoff, S
Willson, KR
TI Characterizing the microscopic physics near moving contact lines using
dynamic contact angle data
SO PHYSICAL REVIEW E
LA English
DT Article
ID MOLECULAR-DYNAMICS; SOLID-SURFACES; MOTION; FLOW; INTERFACE; LIQUIDS;
FLUID; SLIP; SIMULATIONS; SYSTEMS
AB Directly probing the fluid flow and liquid-vapor interface shape in the microscopic immediate vicinity of the moving contact line can only be accomplished in very specific and isolated cases. Yet this physics is critical to macroscopic dynamic wetting. Here we examine the microscopic (or inner) physics of spreading silicone fluids using data of macroscopic dynamic contact angle versus Capillary number Ca=Umu/sigma. This dynamic contact angle is precisely defined so that it can be related back to the microscopic behavior through detailed theory. Our results indicate that the parameters describing the inner region have a detectable dependence on spreading velocity when this velocity exceeds a critical value. This dependence is not scaled (i.e., the data are not collapsed) by Ca, which suggests that an additional time scale must be present in the model of the inner region.
C1 Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA.
NASA, NCMR, Glenn Res Ctr, Cleveland, OH 44135 USA.
Carnegie Mellon Univ, Ctr Complex Fluids Engn, Pittsburgh, PA 15213 USA.
RP Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA.
EM sg2e@andrew.cmu.edu
RI Garoff, Stephen/P-7629-2014
OI Garoff, Stephen/0000-0001-8148-8535
NR 42
TC 20
Z9 20
U1 0
U2 16
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 2470-0045
EI 2470-0053
J9 PHYS REV E
JI Phys. Rev. E
PD SEP
PY 2004
VL 70
IS 3
AR 031608
DI 10.1103/PhysRevE.70.031608
PN 1
PG 9
WC Physics, Fluids & Plasmas; Physics, Mathematical
SC Physics
GA 859XR
UT WOS:000224302200040
PM 15524535
ER
PT J
AU Smelyanskiy, VN
Knysh, S
Morris, RD
AF Smelyanskiy, VN
Knysh, S
Morris, RD
TI Quantum adiabatic optimization and combinatorial landscapes
SO PHYSICAL REVIEW E
LA English
DT Article
ID STATISTICAL-MECHANICS; SATISFIABILITY; EVOLUTION
AB In this paper we analyze the performance of the Quantum Adiabatic Evolution algorithm on a variant of the satisfiability problem for an ensemble of random graphs parametrized by the ratio of clauses to variables, gamma=M/N. We introduce a set of macroscopic parameters (landscapes) and put forward an ansatz of universality for random bit flips. We then formulate the problem of finding the smallest eigenvalue and the excitation gap as a statistical mechanics problem. We use the so-called annealing approximation with a refinement that a finite set of macroscopic variables (instead of only energy) is used, and are able to show the existence of a dynamic threshold gamma=gamma(d) starting with some value of K-the number of variables in each clause. Beyond the dynamic threshold, the algorithm should take an exponentially long time to find a solution. We compare the results for extended and simplified sets of landscapes and provide numerical evidence in support of our universality ansatz. We have been able to map the ensemble of random graphs onto another ensemble with fluctuations significantly reduced. This enabled us to obtain tight upper bounds on the satisfiability transition and to recompute the dynamical transition using the extended set of landscapes.
C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Smelyanskiy, VN (reprint author), NASA, Ames Res Ctr, MS 269-3, Moffett Field, CA 94035 USA.
EM Vadim.N.Smelyanskiy@nasa.gov; knysh@email.arc.nasa.gov;
rdm@email.arc.nasa.gov
NR 36
TC 3
Z9 3
U1 0
U2 1
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 1539-3755
J9 PHYS REV E
JI Phys. Rev. E
PD SEP
PY 2004
VL 70
IS 3
AR 036702
DI 10.1103/PhysRevE.70.036702
PN 2
PG 18
WC Physics, Fluids & Plasmas; Physics, Mathematical
SC Physics
GA 859XS
UT WOS:000224302300106
PM 15524670
ER
PT J
AU Alexakis, A
Calder, AC
Dursi, LJ
Rosner, R
Truran, JW
Fryxell, B
Zingale, M
Timmes, FX
Olson, K
Ricker, P
AF Alexakis, A
Calder, AC
Dursi, LJ
Rosner, R
Truran, JW
Fryxell, B
Zingale, M
Timmes, FX
Olson, K
Ricker, P
TI On the nonlinear evolution of wind-driven gravity waves
SO PHYSICS OF FLUIDS
LA English
DT Article
ID CLASSICAL NOVAE; FINITE-AMPLITUDE; TURBULENT-FLOW; SURFACE-WAVES; WATER;
INSTABILITIES; GENERATION; ENRICHMENT; SIMULATION; CODE
AB We present a study of wind-driven nonlinear interfacial gravity waves using numerical simulations in two dimensions. We consider a case relevant to mixing phenomenon in astrophysical events such as novae in which the density ratio is approximately 1:10. Our physical setup follows the proposed mechanism of Miles [ J. Fluid Mech. 3, 185 (1957) ] for the amplification of such waves. Our results show good agreement with linear predictions for the growth of the waves. We explore how the wind strength affects the wave dynamics and the resulting mixing in the nonlinear stage. We identify two regimes of mixing, namely, the overturning and the cusp-breaking regimes. The former occurs when the wind is strong enough to overcome the gravitational potential barrier and overturn the wave. This result is in agreement with the common notion of turbulent mixing in which density gradients are increased to diffusion scales by the stretching of a series of vortices. In the latter case, mixing is the result of cusp instabilities. Although the wind is not strong enough to overturn the wave in this case, it can drive the wave up to a maximum amplitude where a singular structure at the cusp of the wave forms. Such structures are subject to various instabilities near the cusp that result in breaking the cusp. Mixing then results from these secondary instabilities and the spray-like structures that appear as a consequence of the breaking. (C) 2004 American Institute of Physics.
C1 Univ Chicago, Dept Phys, Chicago, IL 60637 USA.
Univ Chicago, Ctr Astrophys Thermonucl Flashes, Chicago, IL 60637 USA.
Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA.
Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA.
Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA.
NASA, Goddard Space Flight Ctr, UMBC GEST Ctr, Greenbelt, MD 20771 USA.
RP Univ Chicago, Dept Phys, Chicago, IL 60637 USA.
RI Calder, Alan/E-5348-2011; Alexakis, Alexandros/O-8302-2015;
OI Alexakis, Alexandros/0000-0003-2021-7728; Zingale,
Michael/0000-0001-8401-030X; Dursi, Jonathan/0000-0002-4697-798X
NR 37
TC 10
Z9 10
U1 0
U2 1
PU AMER INST PHYSICS
PI MELVILLE
PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA
SN 1070-6631
EI 1089-7666
J9 PHYS FLUIDS
JI Phys. Fluids
PD SEP
PY 2004
VL 16
IS 9
BP 3256
EP 3268
DI 10.1063/1.1771695
PG 13
WC Mechanics; Physics, Fluids & Plasmas
SC Mechanics; Physics
GA 845VO
UT WOS:000223273600008
ER
PT J
AU Turyshev, S
Anderson, J
Nieto, MM
AF Turyshev, S
Anderson, J
Nieto, MM
TI Pioneer anomaly put to the test
SO PHYSICS WORLD
LA English
DT News Item
C1 NASA, Jet Prop Lab, Pasadena, CA 91109 USA.
Los Alamos Natl Lab, Los Alamos, NM 87545 USA.
RP Turyshev, S (reprint author), NASA, Jet Prop Lab, Pasadena, CA 91109 USA.
NR 2
TC 0
Z9 0
U1 0
U2 0
PU IOP PUBLISHING LTD
PI BRISTOL
PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND
SN 0953-8585
J9 PHYS WORLD
JI Phys. World
PD SEP
PY 2004
VL 17
IS 9
BP 21
EP 22
PG 2
WC Physics, Multidisciplinary
SC Physics
GA 950BA
UT WOS:000230831400030
ER
PT J
AU Colavita, MM
Swain, MR
Akeson, RL
Koresko, CD
Hill, RJ
AF Colavita, MM
Swain, MR
Akeson, RL
Koresko, CD
Hill, RJ
TI Effects of atmospheric water vapor on infrared interferometry
SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
LA English
DT Article
ID OPTICAL REFRACTIVE-INDEX; MOIST AIR; TEMPERATURE; HUMIDITY;
FLUCTUATIONS; PRESSURE; LAYER
AB Water vapor, while usually a small contributor to the atmospheric refractive index for astronomical observations at IR wavelengths, is highly dispersive and can introduce optical path length errors affecting high-precision interferometer observing modes. The refractive index of atmospheric water vapor can be computed from a summation over the various IR resonances, and we present values over a range of 1.2 - 13.5 mum. The dispersion of water vapor introduces phase errors across the instrument passband and produces excess noise in interferometer group delay, residual errors in cophasing using a different source wavelength, and coherence loss over broad optical bandwidths. We quantify these effects for the J through N bands, discuss means of amelioration, and consider their implications for differential phase and nulling observing modes.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA.
NOAA, Environm Technol Lab, Boulder, CO 80305 USA.
RP Colavita, MM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA.
EM mark.colavita@jpl.nasa.gov; mark.swain@jpl.nasa.gov;
rla@ipac.caltech.edu; koresko@ipac.caltech.edu; reginald.j.hill@noaa.gov
OI Akeson, Rachel/0000-0001-9674-1564
NR 31
TC 31
Z9 31
U1 0
U2 4
PU UNIV CHICAGO PRESS
PI CHICAGO
PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA
SN 0004-6280
J9 PUBL ASTRON SOC PAC
JI Publ. Astron. Soc. Pac.
PD SEP
PY 2004
VL 116
IS 823
BP 876
EP 885
DI 10.1086/424472
PG 10
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850VB
UT WOS:000223641100008
ER
PT J
AU Stothers, RB
AF Stothers, RB
TI Stratospheric transparency derived from total lunar eclipse colors,
1665-1800
SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC
LA English
DT Review
ID GREENLAND ICE CORE; GREAT DRY FOG; ATMOSPHERIC EXTINCTION; 3-COLOR
PHOTOMETRY; VOLCANIC-ERUPTIONS; ILLUMINATION; CLIMATE; PERIOD; DUST;
MOON
AB A catalog of the observed colors of the totally eclipsed Moon during the period 1665 - 1800 has been prepared from published contemporary reports. Nearly all of the observations were made from Europe. Usable eclipses number 36 in all, or on average, about one eclipse every 4 years. The hue and intensity of the faint illumination of the Moon's disk during totality yield a measure of the aerosol optical depth of the Earth's stratosphere. Unlike the 19th and 20th centuries, the period under study showed a relatively clear stratosphere at nearly all times. Independent but less direct evidence from Greenland ice cores, which contain an annual record of aerosol fallout from large volcanic eruptions, confirms that this was a period of very few, if any, large stratosphere-penetrating volcanic eruptions.
C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA.
RP NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA.
EM rstothers@giss.nasa.gov
NR 165
TC 6
Z9 6
U1 1
U2 2
PU IOP PUBLISHING LTD
PI BRISTOL
PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND
SN 0004-6280
EI 1538-3873
J9 PUBL ASTRON SOC PAC
JI Publ. Astron. Soc. Pac.
PD SEP
PY 2004
VL 116
IS 823
BP 886
EP 893
DI 10.1086/425537
PG 8
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850VB
UT WOS:000223641100009
ER
PT J
AU Li, C
Ban, H
Lin, B
Scripa, RN
Su, CH
Lehoczky, SL
Zhu, S
AF Li, C
Ban, H
Lin, B
Scripa, RN
Su, CH
Lehoczky, SL
Zhu, S
TI Transient torque method: A fast and nonintrusive technique to
simultaneously determine viscosity and electrical conductivity of
semiconducting and metallic melts
SO REVIEW OF SCIENTIFIC INSTRUMENTS
LA English
DT Article
ID OSCILLATING VESSEL METHOD; ROTATING MAGNETIC-FIELD; ALUMINUM-ALLOYS;
MOLTEN METALS; RESISTIVITY; A319; A356
AB A transient torque method was developed to rapidly and simultaneously determine the viscosity and electrical conductivity of liquid metals and molten semiconductors. The experimental setup of the transient torque method is similar to that of the oscillation cup method. The melt sample is sealed inside a fused silica ampoule, and the ampoule is suspended by a long quartz fiber to form a torsional oscillation system. A rotating magnetic field is used to induce a rotating flow in the conductive melt, which causes the ampoule to rotate around its vertical axis. A sensitive angular detector is used to measure the deflection angle of the ampoule. Based on the transient behavior of the deflection angle as the rotating magnetic field is applied, the electrical conductivity and viscosity of the melt can be obtained simultaneously by numberically fitting the data to a set of governing equations. The transient torque viscometer was applied successfully to measure the viscosity and electrical conductivity of high purity mercury at 53.4degreesC. The results were in excellent agreement with published data. The method is nonintrusive; capable of rapid measurement of the viscosity of toxic, high vapor pressure melts at elevated temperatures. In addition, the transient torque viscometer can also be operated as an oscillation cup viscometer to measure just the viscosity of the melt or as a rotating magnetic field method to determine the electrical conductivity of a melt or a solid if desired. (C) 2004 American Institute of Physics.
C1 Univ Alabama, Sch Engn, Birmingham, AL 35294 USA.
NASA, George C Marshall Space Flight Ctr, Micrograv Sci & Applicat Dept, Huntsville, AL 35812 USA.
NASA, George C Marshall Space Flight Ctr, USRA, Huntsville, AL 35812 USA.
RP Li, C (reprint author), Univ Alabama, Sch Engn, Birmingham, AL 35294 USA.
EM chao.li@msfc.nasa.gov
RI Ban, Heng/I-6268-2012
NR 39
TC 3
Z9 4
U1 0
U2 1
PU AMER INST PHYSICS
PI MELVILLE
PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1,
MELVILLE, NY 11747-4501 USA
SN 0034-6748
J9 REV SCI INSTRUM
JI Rev. Sci. Instrum.
PD SEP
PY 2004
VL 75
IS 9
BP 2810
EP 2816
DI 10.1063/1.1781380
PG 7
WC Instruments & Instrumentation; Physics, Applied
SC Instruments & Instrumentation; Physics
GA 866DU
UT WOS:000224754800002
ER
PT J
AU Wertheimer, AC
Heard, WR
Maselko, JM
Smoker, WW
AF Wertheimer, AC
Heard, WR
Maselko, JM
Smoker, WW
TI Relationship of size at return with environmental variation, hatchery
production, and productivity of wild pink salmon in Prince William
Sound, Alaska: does size matter?
SO REVIEWS IN FISH BIOLOGY AND FISHERIES
LA English
DT Article; Proceedings Paper
CT Annual Meeting of the American-Fisheries-Society
CY 2003
CL San Diego, CA
SP Amer Fisheries Soc
DE hatchery interactions; salmon ranching; stock enhancement
ID FACTORS AFFECTING SURVIVAL; NORTH PACIFIC-OCEAN; ONCORHYNCHUS-GORBUSCHA;
BRITISH-COLUMBIA; SOCKEYE-SALMON; CHUM SALMON; STOCK-ENHANCEMENT; KODIAK
ISLAND; TEMPERATURE; NERKA
AB Pink salmon (Oncorhynchus gorbuscha) returning to Prince William Sound (PWS), Alaska, have increased to historically high levels of abundance in recent years, but average body size at return has declined. We examined how body size at return of PWS pink salmon was related to 10 biophysical factors, including the scale of hatchery production. We also examined the effect of body size at return on productivity of wild pink salmon in PWS. For the 1975-1999 brood years, we found that an index of total abundance of pink salmon in the Gulf of Alaska and sea surface temperature during the year of return best explained the variation in pink salmon body size over time. Body size at return was significantly correlated with productivity of wild pink salmon. We used stepwise-regression to fit a generalized linear version of the Ricker spawner-recruit model to determine if body size would explain significant variation in wild-stock productivity in context with other environmental variation, including hatchery production. The results indicate that variability in wild-stock productivity is primarily driven by density-independent factors in the marine environment, but that body size of wild spawners also significantly affects productivity of wild PWS pink salmon. We conclude that the success of large-scale enhancement increasing the total run in PWS may have contributed to the decline in body size because of density-dependent growth in the Gulf of Alaska. We used a simulation model to estimate the impact of hatchery-induced changes in adult body size on wild-stock production in PWS. We estimated an annual wild-stock yield loss of 1.03 million pink salmon, less than 5% of the annual hatchery return of 24.2 million adult pink salmon for brood years 1990-1999.
C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA.
Univ Alaska, Juneau Ctr Fisheries & Ocean Sci, Juneau, AK 99801 USA.
RP Wertheimer, AC (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA.
EM Alex.Wertheimer@noaa.gov
NR 59
TC 24
Z9 25
U1 3
U2 13
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0960-3166
J9 REV FISH BIOL FISHER
JI Rev. Fish. Biol. Fish.
PD SEP
PY 2004
VL 14
IS 3
BP 321
EP 334
DI 10.1007/s11160-004-2942-4
PG 14
WC Fisheries; Marine & Freshwater Biology
SC Fisheries; Marine & Freshwater Biology
GA 934YT
UT WOS:000229746200003
ER
PT J
AU Orsi, JA
Wertheimer, AC
Sturdevant, MV
Fergusson, EA
Mortensen, DG
Wing, BL
AF Orsi, JA
Wertheimer, AC
Sturdevant, MV
Fergusson, EA
Mortensen, DG
Wing, BL
TI Juvenile chum salmon consumption of zooplankton in marine waters of
southeastern Alaska: a bioenergetics approach to implications of
hatchery stock interactions
SO REVIEWS IN FISH BIOLOGY AND FISHERIES
LA English
DT Article; Proceedings Paper
CT Annual Meeting of the American-Fisheries-Society
CY 2003
CL San Diego, CA
SP Amer Fisheries Soc
DE bioenergetics; hatchery interactions; juvenile chum salmon; southeastern
Alaska; zooplankton consumption
ID PERCH PERCA-FLAVESCENS; PRINCE-WILLIAM-SOUND; PACIFIC SALMON;
CARRYING-CAPACITY; BRITISH-COLUMBIA; SOCKEYE-SALMON; MORTALITY; MODEL;
INVERTEBRATES; WASHINGTON
AB Bioenergetics modeling was used to estimate zooplankton prey consumption of hatchery and unmarked stocks of juvenile chum salmon (Oncorhynchus keta) migrating seaward in littoral (nearshore) and neritic (epipelagic offshore) marine habitats of southeastern Alaska. A series of model runs were completed using biophysical data collected in Icy Strait, a regional salmon migration corridor, in May, June, July, August, and September of 2001. These data included a temperature (1-m surface versus surface to 20-m average), zooplankton standing crop (surface to 20-m depth versus entire water column), chum salmon diet (percent weight of prey type consumed), energy densities, and weight. Known numbers of hatchery releases were used in a cohort reconstruction model to estimate total abundance of hatchery and wild chum salmon in the northern region of southeastern Alaska, given average survival to adults and for two different (low and high) early marine littoral mortality rate assumptions. Total prey consumption was relatively insensitive to temperature differences associated with the depths potentially utilized by juvenile chum salmon. However, the magnitudes and temporal patterns of total prey consumed differed dramatically between the low and high mortality rate assumptions. Daily consumption rates from the bioenergetics model and CPUE abundance from sampling in Icy Strait were used to estimate amount and percentage of zooplankton standing crop consumed by mixed stocks of chum salmon. We estimated that only a small percentage of the available zooplankton was consumed by juvenile chum salmon, even during peak abundances of marked hatchery and unmarked mixed stocks in July. Total daily consumption of zooplankton by all stock groups of juvenile chum salmon was estimated to be between 330 and 1764 g/km(2) d(-1) from June to September in the neritic habitat of Icy Strait. As with any modeling exercise, model outputs can be misleading if input parameters and underlying assumptions are not valid; therefore, additional studies are warranted, especially to determine physiological input parameters, and to improve abundance and mortality estimates specific to juvenile chum salmon. Future bioenergetics modeling is also needed to evaluate consumption by the highly abundant, vertically migrating planktivorous that co-occurred in our study; we suggest that these fishes have a greater impact on the zooplankton standing crop in Icy Strait than do hatchery stock groups of juvenile chum salmon.
C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA.
RP Orsi, JA (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA.
EM joe.orsi@noaa.gov
NR 65
TC 17
Z9 17
U1 0
U2 1
PU SPRINGER
PI DORDRECHT
PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS
SN 0960-3166
J9 REV FISH BIOL FISHER
JI Rev. Fish. Biol. Fish.
PD SEP
PY 2004
VL 14
IS 3
BP 335
EP 359
DI 10.1007/s11160-004-3813-8
PG 25
WC Fisheries; Marine & Freshwater Biology
SC Fisheries; Marine & Freshwater Biology
GA 934YT
UT WOS:000229746200004
ER
PT J
AU Halpin, PM
Strub, PT
Peterson, WT
Baumgartner, TR
AF Halpin, PM
Strub, PT
Peterson, WT
Baumgartner, TR
TI An overview of interactions among oceanography, marine ecosystems,
climatic and human disruptions along the eastern margins of the Pacific
Ocean
SO REVISTA CHILENA DE HISTORIA NATURAL
LA English
DT Article
DE eastern boundary currents; anthropogenic effects; marine community
ecology; fisheries; interdecadal variability
ID CALIFORNIA CURRENT SYSTEM; ROCKY INTERTIDAL COMMUNITY; 1982-1983
EL-NINO; GASTROPOD CONCHOLEPAS-CONCHOLEPAS; KELP FOREST COMMUNITY;
COASTAL UPWELLING JET; SEA-LEVEL CHANGES; NORTH PACIFIC; CENTRAL CHILE;
INTERANNUAL VARIABILITY
AB Physical processes, biotic processes and human activities all act to shape marine ecosystems. Future management of these valuable ecosystems requires an integrative approach that takes into account complicated organismal interactions, oceanographic processes that span large scales of time and space, and how anthropogenic effects interact with the natural environment. The temperate west coasts of North and South America represent a unique opportunity for comparison, as many of the same oceanographic processes, particularly upwelling, occur off both coasts. Additionally, a number of marine ecosystems in both areas have surprising parallels. Here we present an overview of the oceanographic processes that dominate the coastlines, and give examples of ecosystems and the effects that oceanography, human activities and their interaction have on the communities.
C1 Oregon State Univ, Dept Zool, Corvallis, OR 97331 USA.
Univ Calif Santa Barbara, Inst Marine Sci, Santa Barbara, CA 93106 USA.
Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA.
NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Newport, OR 97365 USA.
Ctr Invest Cient & Educ Super Ensenada, Div Oceanol, Ensenada, Baja California, Mexico.
RP Halpin, PM (reprint author), Oregon State Univ, Dept Zool, Corvallis, OR 97331 USA.
EM halpin@lifesci.ucsb.edu
NR 225
TC 19
Z9 20
U1 0
U2 13
PU SOCIEDAD BIOLGIA CHILE
PI SANTIAGO
PA CASILLA 16164, SANTIAGO 9, CHILE
SN 0716-078X
J9 REV CHIL HIST NAT
JI Rev. Chil. Hist. Nat.
PD SEP
PY 2004
VL 77
IS 3
BP 371
EP 409
PG 39
WC Biodiversity Conservation; Ecology
SC Biodiversity & Conservation; Environmental Sciences & Ecology
GA 857KC
UT WOS:000224114200002
ER
PT J
AU Freund, FT
Takeuchi, A
Lau, BWS
Post, R
Keefner, J
Mellon, J
Al-Manaseer, A
AF Freund, FT
Takeuchi, A
Lau, BWS
Post, R
Keefner, J
Mellon, J
Al-Manaseer, A
TI Stress-induced changes in the electrical conductivity of igneous rocks
and the generation of ground currents
SO TERRESTRIAL ATMOSPHERIC AND OCEANIC SCIENCES
LA English
DT Article
DE pre-earthquake phenomena; electrical conductivity; stress; magnetic
field; ionization; EM emission; thermal anomalies
ID NOMINALLY ANHYDROUS MINERALS; ELECTROMAGNETIC EMISSIONS;
CHARGE-DISTRIBUTION; CONTINENTAL-CRUST; EARTHS MANTLE; EARTHQUAKE;
FRACTURE; SIGNALS; MODEL; WATER
AB If we can ever hope to understand the non-seismic signals that the Earth sends out before major earthquakes, we need to understand the physics of rocks under increased levels of stress. In particular we need to understand the generation of electrical currents in the ground. We have begun to study how electrical conductivity of igneous rocks changes under stress and what types of charge carriers are involved. We show that quartz-rich granite and quartz-free anorthosite both generate electronic charge carriers when subjected to stress. The charge carriers are positive holes (p-holes), i.e., defect electrons on the oxygen anion sublattice. They spread out of the stressed rock volume, the "source volume", into the surrounding unstressed rocks. Time-varying ground currents are required to generate pre-earthquake local magnetic field anomalies and low-frequency electromagnetic emissions. We posit that stress-induced activation of p-hole charge carriers and their outflow from the source volume is the basic process by which ground currents can be generated in the Earth's crust. We propose that the arrival of p-holes at the Earth's surface leads to changes in the ground potential that may induce ionospheric perturbations. We further propose that the build-up of high electric fields at the ground surface can ionize the. air, hence cause ion emission and corona discharges. When p-holes recombine at the ground surface, they are expected to form vibrationally highly excited O-O bonds. The de-excitation of these O-O bonds will lead to stimulated mid-IR emission, which may explain the reported pre-earthquake "thermal anomalies" identified in satellite images.
C1 Univ Maryland Baltimore Cty, GEST, Baltimore, MD 21228 USA.
San Jose State Univ, Dept Phys, San Jose, CA 95112 USA.
S Dakota Sch Mines & Technol, Rapid City, SD 57701 USA.
Oregon State Univ, Dept Phys, Corvallis, OR 97331 USA.
San Jose State Univ, Dept Civil Engn, San Jose, CA 95192 USA.
RP Freund, FT (reprint author), NASA, Goddard Space Flight Ctr, Geodynam Branch, MS 921, Greenbelt, MD 20771 USA.
EM ffreund@core2.gsfc.nasa.gov
RI Takeuchi, Akihiro/E-8960-2011
NR 76
TC 24
Z9 29
U1 0
U2 5
PU CHINESE GEOSCIENCE UNION
PI TAIPEI
PA PO BOX 23-59, TAIPEI 10764, TAIWAN
SN 1017-0839
J9 TERR ATMOS OCEAN SCI
JI Terr. Atmos. Ocean. Sci.
PD SEP
PY 2004
VL 15
IS 3
BP 437
EP 467
PG 31
WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences;
Oceanography
SC Geology; Meteorology & Atmospheric Sciences; Oceanography
GA 877AS
UT WOS:000225540800010
ER
PT J
AU Bushnell, DM
Thangam, S
AF Bushnell, DM
Thangam, S
TI Special issue - Modeling and simulation of turbulent flows - Preface
SO THEORETICAL AND COMPUTATIONAL FLUID DYNAMICS
LA English
DT Biographical-Item
C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA.
Stevens Inst Technol, Hoboken, NJ 07030 USA.
RP Bushnell, DM (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA.
NR 0
TC 0
Z9 0
U1 0
U2 0
PU SPRINGER
PI NEW YORK
PA 233 SPRING STREET, NEW YORK, NY 10013 USA
SN 0935-4964
J9 THEOR COMP FLUID DYN
JI Theor. Comput. Fluid Dyn.
PD SEP
PY 2004
VL 17
IS 5-6
BP 297
EP 298
DI 10.1007/s00162-004-0117-5
PG 2
WC Mechanics; Physics, Fluids & Plasmas
SC Mechanics; Physics
GA 862YG
UT WOS:000224526800001
ER
PT J
AU Rubinstein, R
Zhou, Y
AF Rubinstein, R
Zhou, Y
TI Turbulence modeling for the axially rotating pipe from the viewpoint of
analytical closures
SO THEORETICAL AND COMPUTATIONAL FLUID DYNAMICS
LA English
DT Article; Proceedings Paper
CT Symposium on Modeling and Simulation of Turbulent Flows
CY JUL 06-10, 2003
CL Honolulu, HI
SP ASME, JSME
DE rotating turbulence. rotating pipe flow; mixing length model; frame
indifference
ID ISOTROPIC TURBULENCE; STATISTICAL-ANALYSIS; REYNOLDS STRESS;
EDDY-VISCOSITY; FLOW
AB A single-point model eddy viscosity model of rotation effects on the turbulent flow in an axially rotating pipe is developed based on two-point closure theories. Rotation is known to impede energy transfer in turbulence; this fact is reflected in the present model through a reduced eddy viscosity, leading to laminarization of the mean velocity profile and return to a laminar friction law in the rapid rotation limit. This model is compared with other proposals including linear redistribution effects through the rapid pressure-strain correlation, Richardson number modification of the eddy viscosity in a model of non-rotating turbulence, and the reduction of turbulence through the suppression of near-wall production mechanisms.
C1 NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA.
NASA, Langley Res Ctr, Inst Comp Applicat Sci & Engn, Hampton, VA 23681 USA.
RP Rubinstein, R (reprint author), NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA.
EM r.rubinstein@larc.nasa.gov
NR 33
TC 3
Z9 3
U1 0
U2 4
PU SPRINGER
PI NEW YORK
PA 233 SPRING STREET, NEW YORK, NY 10013 USA
SN 0935-4964
J9 THEOR COMP FLUID DYN
JI Theor. Comput. Fluid Dyn.
PD SEP
PY 2004
VL 17
IS 5-6
BP 299
EP 312
DI 10.1007/s00162-004-0111-y
PG 14
WC Mechanics; Physics, Fluids & Plasmas
SC Mechanics; Physics
GA 862YG
UT WOS:000224526800002
ER
PT J
AU So, RMC
Jin, LH
Gatski, TB
AF So, RMC
Jin, LH
Gatski, TB
TI An explicit algebraic Reynolds stress and heat flux model for
incompressible turbulence: Part I Non-isothermal flow
SO THEORETICAL AND COMPUTATIONAL FLUID DYNAMICS
LA English
DT Article; Proceedings Paper
CT Symposium on Modeling and Simulation of Turbulent Flows
CY JUL 06-10, 2003
CL Honolulu, HI
SP ASME, JSME
DE heat flux model; algebraic model; turbulence model
ID SCALAR-FLUX; PASSIVE SCALAR; SHEAR FLOWS; APPROXIMATION; EQUATIONS;
VISCOSITY; CLOSURE
AB Tensor representation theory is used to derive an explicit algebraic model that consists of an explicit algebraic stress model (EASM) and an explicit algebraic heat flux model (EAHFM) for two-dimensional (2-D) incompressible non-isothermal turbulent flows. The representation methodology used for the heat flux vector is adapted from that used for the polynomial representation of the Reynolds stress anisotropy tensor. Since the methodology is based on the formation of invariants from either vector or tensor basis sets, it is possible to derive explicit polynomial vector expansions for the heat flux vector. The resulting EAHFM is necessarily coupled with the turbulent velocity field through an EASM for the Reynolds stress anisotropy. An EASM has previously been derived by Jongen and Gatski [10]. Therefore, it is used in conjunction with the derived EAHFM to form the explicit algebraic model for incompressible 2-D flows. This explicit algebraic model is analyzed and compared with previous formulations including its ability to approximate the commonly accepted value for the turbulent Prandtl number. The effect of pressure-scrambling vector model calibration on predictive performance is also assessed. Finally, the explicit algebraic model is validated against a 2-D homogeneous shear flow with a variety of thermal gradients.
C1 Hong Kong Polytech Univ, Dept Mech Engn, Hong Kong, Hong Kong, Peoples R China.
Tsing Hua Univ, Dept Engn Mech, Beijing 100084, Peoples R China.
NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA.
RP So, RMC (reprint author), Hong Kong Polytech Univ, Dept Mech Engn, Hong Kong, Hong Kong, Peoples R China.
EM mmmcso@polyu.edu.hk
NR 35
TC 8
Z9 9
U1 0
U2 3
PU SPRINGER
PI NEW YORK
PA 233 SPRING STREET, NEW YORK, NY 10013 USA
SN 0935-4964
J9 THEOR COMP FLUID DYN
JI Theor. Comput. Fluid Dyn.
PD SEP
PY 2004
VL 17
IS 5-6
BP 351
EP 376
DI 10.1007/s00162-004-0122-8
PG 26
WC Mechanics; Physics, Fluids & Plasmas
SC Mechanics; Physics
GA 862YG
UT WOS:000224526800005
ER
PT J
AU So, RMC
Jin, LH
Gatski, TB
AF So, RMC
Jin, LH
Gatski, TB
TI An explicit algebraic Reynolds stress and heat flux model for
incompressible turbulence: Part II Buoyant flow
SO THEORETICAL AND COMPUTATIONAL FLUID DYNAMICS
LA English
DT Article; Proceedings Paper
CT Symposium on Modeling and Simulation of Turbulent Flows
CY JUL 06-10, 2003
CL Honolulu, HI
SP ASME, JSME
DE buoyant flow modeling; algebraic model; heat flux model; turbulence
model
ID STABLY STRATIFIED MEDIUM; SCALAR-FLUX; SHEAR FLOWS; EQUILIBRIUM STATES;
PASSIVE SCALAR; APPROXIMATION; VISCOSITY
AB This paper presents a derivation of an explicit algebraic model for two-dimensional (2-D) buoyant flows. It is an extension of the work reported in Part I (So et al. [27]). The tensor representation method of Jongen and Gatski [14] is extended to derive an explicit algebraic Reynolds stress model (EASM) for 2-D buoyant flow invoking the Boussinesq approximation. The projection methodology is further extended to treat the heat flux transport equation in the derivation of an explicit algebraic heat flux model (EAHFM) for buoyant flow. Again, the weak equilibrium assumption is invoked for the scaled Reynolds stress and scaled heat flux equation. An explicit algebraic model for buoyant flows is then formed with the EASM and EAHFM. From the derived EAHFM, an expression for the thermal diffusivity tensor in buoyant shear flows is deduced. Furthermore, a turbulent Prandtl number (Pr-T) for each of the three heat flux directions is determined. These directional Pr-T are found to be a function of the gradient Richardson number. Alternatively, a scalar Pr-T can be derived; its value is compared with the directional Pr-T. The EASM and EAHFM are used to calculate 2-D homogeneous buoyant shear flows and the results are compared with direct numerical simulation data and other model predictions, where good agreement is obtained.
C1 Hong Kong Polytech Univ, Dept Mech Engn, Hong Kong, Hong Kong, Peoples R China.
Tsing Hua Univ, Dept Engn Mech, Beijing 100084, Peoples R China.
NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA.
RP So, RMC (reprint author), Hong Kong Polytech Univ, Dept Mech Engn, Hong Kong, Hong Kong, Peoples R China.
EM mmmcso@polyu.edu.hk
NR 33
TC 7
Z9 7
U1 0
U2 1
PU SPRINGER
PI NEW YORK
PA 233 SPRING STREET, NEW YORK, NY 10013 USA
SN 0935-4964
J9 THEOR COMP FLUID DYN
JI Theor. Comput. Fluid Dyn.
PD SEP
PY 2004
VL 17
IS 5-6
BP 377
EP 406
DI 10.1007/s00162-004-0123-7
PG 30
WC Mechanics; Physics, Fluids & Plasmas
SC Mechanics; Physics
GA 862YG
UT WOS:000224526800006
ER
PT J
AU DellaCorte, C
AF DellaCorte, C
TI WTC countdown has begun
SO TRIBOLOGY & LUBRICATION TECHNOLOGY
LA English
DT Editorial Material
C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
RP DellaCorte, C (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA.
EM cdellacorte@stle.org
NR 0
TC 0
Z9 0
U1 0
U2 0
PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS
PI PARK RIDGE
PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA
SN 0024-7154
J9 TRIBOL LUBR TECHNOL
JI Tribol. Lubr. Technol.
PD SEP
PY 2004
VL 60
IS 9
BP 6
EP 6
PG 1
WC Engineering, Mechanical
SC Engineering
GA 851DO
UT WOS:000223665900002
ER
PT J
AU Larour, E
Rignot, E
Aubry, D
AF Larour, E
Rignot, E
Aubry, D
TI Modelling of rift propagation on Ronne Ice Shelf, Antarctica, and
sensitivity to climate change
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID SAR INTERFEROMETRY; DYNAMICS; STREAM; CREVASSES; FRONT
AB The calving of icebergs from large Antarctic ice shelves is controlled mainly by the formation and propagation of rifts originating from the side margins of the ice shelf and local areas of grounding. Using InSAR, we observe the evolution of rifts along Hemmen Ice Rise, on Ronne Ice Shelf, Antarctica prior to the large calving event of October 1998. We couple these observations with a computer model combining the viscous flow of an ice shelf with a linear elastic fracture mechanics description of the propagation of rifts. The model reveals that the ice melange trapped in between the rifts exerts a major control on the propagation of rifts, and in turn on ice shelf stability. Melting of the ice melange from oceanic or atmospheric warming would significantly increase the propagation rate of rifts and threaten the ice-shelf stability.
C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Ecole Cent Paris, Lab Mecan Sols Struct & Mat, Chatenay Malabry, France.
RP Larour, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 200-227, Pasadena, CA 91109 USA.
EM eric.larour@jpl.nasa.gov
RI Rignot, Eric/A-4560-2014; Aubry, Denis/M-7880-2014
OI Rignot, Eric/0000-0002-3366-0481;
NR 19
TC 26
Z9 28
U1 0
U2 8
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
EI 1944-8007
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD AUG 31
PY 2004
VL 31
IS 16
AR L16404
DI 10.1029/2004GL020077
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 854FV
UT WOS:000223887900001
ER
PT J
AU Xie, H
Ofman, L
Vinas, A
AF Xie, H
Ofman, L
Vinas, A
TI Multiple ions resonant heating and acceleration by Alfven/cyclotron
fluctuations in the corona and the solar wind
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
DE ion cylotron waves; solar wind heating; microinstabilities
ID KINETIC SHELL-MODEL; CYCLOTRON-RESONANCE; ALFVEN WAVES; TEMPERATURE
ANISOTROPY; HYBRID SIMULATIONS; HIGH-BETA; HOLES; INSTABILITY;
CONSTRAINTS; GENERATION
AB [1] We study the interaction between protons, multiple minor ions (O5+, He++), and a given Alfven/cyclotron fluctuation spectra in the corona and the solar wind. One-dimensional hybrid simulations are performed in initially homogeneous, collisionless, magnetized plasma with waves propagating parallel to the background magnetic field. The self-consistent hybrid simulations and linear Vlasov theory are used to study the effect of the driving spectrum, ion drift velocity, and microinstabilities on the coronal plasma and solar wind heating. The simulation results provide a clear picture of wave-particle interaction and successfully explain ( 1) how the driving spectrum frequency range and the power law index affect the resonant heating, ( 2) how ion double-peak distribution is formed and how differential flows affect the resonant interaction via the change of the resonant wave dispersion relation, and ( 3) how local microinstabilities affect minor ion heating and constraint the values of plasma parameters observed in the solar wind.
C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Catholic Univ Amer, Washington, DC 20064 USA.
RP NASA, Goddard Space Flight Ctr, Code 682, Greenbelt, MD 20771 USA.
EM hong@aurora.nascom.nasa.gov; ofman@waves.gsfc.nasa.gov;
adolfo.figueroa-vinas.1@gsfc.nasa.gov
NR 53
TC 33
Z9 33
U1 0
U2 3
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9380
EI 2169-9402
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD AUG 31
PY 2004
VL 109
IS A8
AR A08103
DI 10.1029/2004JA010501
PG 12
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 854GM
UT WOS:000223889900001
ER
PT J
AU Caspi, A
Beutter, BR
Eckstein, MP
AF Caspi, A
Beutter, BR
Eckstein, MP
TI The time course of visual information accrual guiding eye movement
decisions
SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF
AMERICA
LA English
DT Article
ID SACCADE TARGET SELECTION; SUPERIOR COLLICULUS; SEARCH; DISSOCIATION;
INITIATION; RESPONSES; FEATURES; SIGNALS; SYSTEM; FIELDS
AB Saccadic eye movements are the result of neural decisions about where to move the eyes. These decisions are based on visual information accumulated before the saccade; however, during an approximate to100-ms interval immediately before the initiation of an eye movement, new visual information cannot influence the decision. Does the brain simply ignore information presented during this brief interval or is the information used for the subsequent saccade? Our study examines how and when the brain integrates visual information through time to drive saccades during visual search. We introduce a new technique, saccade-contingent reverse correlation, that measures the time course of visual information accrual driving the first and second saccades. Observers searched for a contrast-defined target among distractors. Independent contrast noise was added to the target and distractors every 25 ms. Only noise presented in the time interval in which the brain accumulates information will influence the saccadic decisions. Therefore, we can retrieve the time course of saccadic information accrual by averaging the time course of the noise, aligned to saccade initiation, across all trials with saccades to distractors. Results show that before the first saccade, visual information is being accumulated simultaneously for the first and second saccades. Furthermore, information presented immediately before the first saccade is not used in making the first saccadic decision but instead is stored and used by the neural processes driving the second saccade.
C1 Univ Calif Santa Barbara, Dept Psychol, Santa Barbara, CA 93106 USA.
NASA, Ames Res Ctr, Moffett Field, CA 94035 USA.
RP Caspi, A (reprint author), Bar Ilan Univ, Leslie & Susan Gonda Multidisciplinary Brain Res, IL-52900 Ramat Gan, Israel.
EM avi.caspi@psych.ucsb.edu
NR 31
TC 65
Z9 67
U1 1
U2 2
PU NATL ACAD SCIENCES
PI WASHINGTON
PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA
SN 0027-8424
J9 P NATL ACAD SCI USA
JI Proc. Natl. Acad. Sci. U. S. A.
PD AUG 31
PY 2004
VL 101
IS 35
BP 13086
EP 13090
DI 10.1073/pnas.0305329101
PG 5
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 851OP
UT WOS:000223694700056
PM 15326284
ER
PT J
AU Buckel, JA
Stoner, AW
AF Buckel, JA
Stoner, AW
TI Negative effects of increasing group size on foraging in two estuarine
piscivores
SO JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY
LA English
DT Article
DE density-dependent; group size; Morone saxatilis; piscivory; Pomatomus
saltatrix; predator-prey interactions
ID HUNTING BEHAVIOR; STRIPED BASS; SHOAL SIZE; PREDATORS; PREY; ALDABRA;
FISHES; GROWTH; PISCES
AB The effect of predator density on per capita ingestion rates in two estuarine predators, age-0 bluefish (Pomatomus saltatrix L.) and age-1 striped bass (Morone saxatilis W.), was examined in a 121,000-1 research aquarium. Group size treatments were 3, 6, 12, and 24 predators; each treatment was provided with 100 prey (mummichog killifish, Fundulus heteroclitus L.) during a 22-h feeding trial. The behaviors of predator and prey were recorded. Predator type and group size had a significant effect on per capita ingestion rates. Bluefish had significantly higher per capita ingestion rates compared to striped bass. For bluefish, per capita ingestion rate was highest in the three predator group, while for striped bass, individuals in the six predator treatment had the highest ingestion rates. From these maxima, per capita ingestion rate values declined to their lowest values in the 24 predator treatment for both species. Several factors that may be responsible for lowered per capita ingestion rates at higher group sizes include predator interference, prey depletion, and antipredator behaviors of prey. For juvenile bluefish and striped bass being a member of a relatively large group may lead to decreased individual ingestion rates. Given that large group sizes of these species occur in nature, we conclude that these foraging costs must be outweighed by benefits of group membership. (C) 2004 Elsevier B.V. All rights reserved.
C1 Univ N Carolina, Ctr Marine Sci & Technol, Dept Zool, Morehead City, NC 28557 USA.
Oregon State Univ, Hatfield Marine Sci Ctr, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Newport, OR 97365 USA.
RP Buckel, JA (reprint author), Univ N Carolina, Ctr Marine Sci & Technol, Dept Zool, 303 Coll Circle, Morehead City, NC 28557 USA.
EM jeffrey_buckel@ncsu.edu
NR 22
TC 12
Z9 13
U1 0
U2 5
PU ELSEVIER SCIENCE BV
PI AMSTERDAM
PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
SN 0022-0981
J9 J EXP MAR BIOL ECOL
JI J. Exp. Mar. Biol. Ecol.
PD AUG 30
PY 2004
VL 307
IS 2
BP 183
EP 196
DI 10.1016/j.jembe.2004.02.003
PG 14
WC Ecology; Marine & Freshwater Biology
SC Environmental Sciences & Ecology; Marine & Freshwater Biology
GA 840PY
UT WOS:000222872700003
ER
PT J
AU Korontzi, S
Roy, DP
Justice, CO
Ward, DE
AF Korontzi, S
Roy, DP
Justice, CO
Ward, DE
TI Modeling and sensitivity analysis of fire emissions in southern Africa
during SAFARI 2000
SO REMOTE SENSING OF ENVIRONMENT
LA English
DT Reprint
ID SAVANNA FIRES; TRACE GASES; CARBON EMISSIONS; BIOMASS; ECOSYSTEMS;
ATMOSPHERE; PARTICLES; PRODUCTS; IMAGERY
AB This paper uses three recently generated southern African satellite burned area products for the month of September 2000 in a sensitivity study of regional biomass burning emissions for a number of trace gases and particulates. Differences in the extent and location of areas burned among products generated from Moderate Resolution Imaging Spectroradiometer (MODIS), Systeme Pour l'Observation de la Terre (SPOT-VEGETATION), and Along Track Scanning Radiometer (ATSR-2) data are significant and result in different emissions estimates for woodland and grassland land cover types. Due to the different emission profiles in woodlands and grasslands, favoring relatively more products of incomplete combustion in woodlands compared with products of complete combustion in grasslands in the late dry season, these changes are not proportional to the differences in the burned area amounts. The importance of accurate burned area information not just in terms of the total area but also in terms of its spatial distribution becomes apparent from our modeling results. This paper highlights the urgent need for satellite data producers to provide accuracy assessments associated with satellite-derived products. Preferably, these accuracy data will be spatially explicit, or defined in a way that can be applied in a spatially explicit modeling context, to enable emissions uncertainties to be defined with respect to different landscape units in support of greenhouse gas emissions reporting. (C) 2004 Elsevier Inc. All rights reserved.
C1 Univ Maryland, Dept Geog, College Pk, MD 20742 USA.
NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Enviropyron LLC, White Salmon, WA 98672 USA.
RP Univ Maryland, Dept Geog, 2181 LeFrak, College Pk, MD 20742 USA.
EM stef@hermes.geog.umd.edu
NR 46
TC 23
Z9 24
U1 0
U2 4
PU ELSEVIER SCIENCE INC
PI NEW YORK
PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA
SN 0034-4257
EI 1879-0704
J9 REMOTE SENS ENVIRON
JI Remote Sens. Environ.
PD AUG 30
PY 2004
VL 92
IS 3
BP 376
EP 396
DI 10.1016/j.rse.2004.06.023
PG 21
WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic
Technology
SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science &
Photographic Technology
GA 856CG
UT WOS:000224020600010
ER
PT J
AU Burlaga, LF
Vinas, AF
AF Burlaga, LF
Vinas, AF
TI Multi-scale probability distributions of solar wind speed fluctuations
at 1 AU described by a generalized Tsallis distribution
SO GEOPHYSICAL RESEARCH LETTERS
LA English
DT Article
ID HIGH REYNOLDS-NUMBER; TURBULENCE; STATISTICS
AB The probability distributions of changes in the solar speed observed at 1 AU by ACE during 1999 on scales from 1 hour to 171 days and at a scale of 64 sec can be described by a single distribution function. The function is a simple generalization of the Tsallis q-distribution, a probability distribution that was derived from nonextensive statistical mechanics. The fluctuations in speed are related to (1) intermittent turbulence and shocks on the smallest scales; (2) ejecta, corotating streams, slow flows, interaction regions, etc. on intermediate scales; and (3) systems of interacting flows involving all of these features, on scales greater than the solar rotation period.
C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA.
RP Burlaga, LF (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Mail Code 692,Bldg 21,Rm 244, Greenbelt, MD 20771 USA.
EM leonard.f.burlaga@nasa.gov
NR 21
TC 26
Z9 27
U1 0
U2 0
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0094-8276
J9 GEOPHYS RES LETT
JI Geophys. Res. Lett.
PD AUG 28
PY 2004
VL 31
IS 16
AR L16807
DI 10.1029/2004GL020715
PG 4
WC Geosciences, Multidisciplinary
SC Geology
GA 850MC
UT WOS:000223614900004
ER
PT J
AU Ebihara, Y
Fok, MC
Wolf, RA
Immel, TJ
Moore, TE
AF Ebihara, Y
Fok, MC
Wolf, RA
Immel, TJ
Moore, TE
TI Influence of ionosphere conductivity on the ring current
SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
LA English
DT Article
DE magnetic storms; ring current; ionosphere conductivity; sheilding; Dst
index; numerical simulation
ID ELECTRIC-FIELDS; SEMIANNUAL VARIATION; MAGNETOSPHERIC SUBSTORM;
QUANTITATIVE SIMULATION; GEOMAGNETIC STORMS; MAGNETIC-FIELD;
SOLAR-FLARE; IMAGE SPACECRAFT; LOW LATITUDES; DST INDEX
AB Using the Comprehensive Ring Current Model (CRCM), which self-consistently solves the kinetic equation of ring current protons and the closure of the electric current between the magnetosphere and ionosphere, we have studied how different changes in the ionospheric conductivity affect the strength of the ring current. The conductivity for F10.7=250x10(4) Janskys (Jy) (solar maximum condition) results in a ring current that is about 29% stronger than for F10.7=70x10(4) Jy (solar minimum condition). The conductivity at equinox results in a ring current that is about 5% stronger than at solstice because the two-hemisphere height-integrated conductivities at equinox are higher than at solstice. This would be a new mechanism for explaining the semiannual variation of Dst. Simulation with a realistic auroral conductivity estimated from the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE)/Far Ultraviolet Imager (FUV) auroral imager data reveals the fact that auroral brightenings do not significantly change the intensity of the ring current. The overshielding condition is found to be produced when the auroral conductivity decreases abruptly near the Dst minimum, triggering a rapid decay of the ring current. The ring current is shown to be influenced not only by the interplanetary magnetic field and the solar wind but also by solar radiation and morphological features of the auroral electron precipitation as well.
C1 NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA.
Rice Univ, Dept Phys & Astron, Houston, TX 77251 USA.
Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA.
RP NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Code 692, Greenbelt, MD 20771 USA.
EM ebihara@lepvax.gsfc.nasa.gov; mei-ching.h.fok@nasa.gov; rawolf@rice.edu;
immel@ssl.berkeley.edu; thomas.e.moore@nasa.gov
RI Ebihara, Yusuke/D-1638-2013; Fok, Mei-Ching/D-1626-2012; Moore,
Thomas/D-4675-2012
OI Ebihara, Yusuke/0000-0002-2293-1557; Moore, Thomas/0000-0002-3150-1137
NR 76
TC 34
Z9 33
U1 0
U2 0
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9380
EI 2169-9402
J9 J GEOPHYS RES-SPACE
JI J. Geophys. Res-Space Phys.
PD AUG 28
PY 2004
VL 109
IS A8
AR A08205
DI 10.1029/2003JA010351
PG 14
WC Astronomy & Astrophysics
SC Astronomy & Astrophysics
GA 850MY
UT WOS:000223617300001
ER
PT J
AU Zappa, CJ
Asher, WE
Jessup, AT
Klinke, J
Long, SR
AF Zappa, CJ
Asher, WE
Jessup, AT
Klinke, J
Long, SR
TI Microbreaking and the enhancement of air-water transfer velocity
SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
LA English
DT Article
DE microbreaking; gas transfer; waves
ID SEA GAS TRANSFER; MICROSCALE WAVE BREAKING; CAPILLARY WAVES; INFRARED
IMAGERY; GRAVITY-WAVES; WIND-WAVES; FLUX; TURBULENCE; INTERFACE;
EXCHANGE
AB [1] The role of microscale wave breaking in controlling the air-water transfer of heat and gas is investigated in a laboratory wind-wave tank. The local heat transfer velocity, k(H), is measured using an active infrared technique and the tank-averaged gas transfer velocity, k(G), is measured using conservative mass balances. Simultaneous, colocated infrared and wave slope imagery show that wave-related areas of thermal boundary layer disruption and renewal are the turbulent wakes of microscale breaking waves, or microbreakers. The fractional area coverage of microbreakers, A(B), is found to be 0.1-0.4 in the wind speed range 4.2-9.3 m s(-1) for cleaned and surfactant-influenced surfaces, and k(H) and k(G) are correlated with A(B). The correlation of k(H) with A(B) is independent of fetch and the presence of surfactants, while that for k(G) with A(B) depends on surfactants. Additionally, A(B) is correlated with the mean square wave slope, [S-2], which has shown promise as a correlate for k(G) in previous studies. The ratio of k(H) measured inside and outside the microbreaker wakes is 3.4, demonstrating that at these wind speeds, up to 75% of the transfer is the direct result of microbreaking. These results provide quantitative evidence that microbreaking is the dominant mechanism contributing to air-water heat and gas transfer at low to moderate wind speeds.
C1 Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA.
Univ Calif San Diego, Scripps Inst Oceanog, Phys Oceanog Res Div, La Jolla, CA 92093 USA.
NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA.
RP Zappa, CJ (reprint author), Columbia Univ, Lamont Doherty Earth Observ, 61 Route 9W, Palisades, NY 10964 USA.
EM zappa@ldeo.columbia.edu; asher@apl.washington.edu;
jessup@apl.washington.edu; jklinke@ucsd.edu; steve@airsea.wff.nasa.gov
RI Long, Steven/D-7248-2012; Jessup, Andrew/E-5625-2017
NR 45
TC 56
Z9 57
U1 0
U2 11
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 2169-9275
EI 2169-9291
J9 J GEOPHYS RES-OCEANS
JI J. Geophys. Res.-Oceans
PD AUG 27
PY 2004
VL 109
IS C8
AR C08S16
DI 10.1029/2003JC001897
PG 18
WC Oceanography
SC Oceanography
GA 850MP
UT WOS:000223616300002
ER
PT J
AU Banerjee, SS
Goldberg, S
Soibel, A
Myasoedov, Y
Rappaport, M
Zeldov, E
de la Cruz, F
van der Beek, CJ
Konczykowski, M
Tamegai, T
Vinokur, VM
AF Banerjee, SS
Goldberg, S
Soibel, A
Myasoedov, Y
Rappaport, M
Zeldov, E
de la Cruz, F
van der Beek, CJ
Konczykowski, M
Tamegai, T
Vinokur, VM
TI Vortex nanoliquid in high-temperature superconductors
SO PHYSICAL REVIEW LETTERS
LA English
DT Article
ID BI2SR2CACU2O8 CRYSTALS; FLAT SUPERCONDUCTORS; MELTING TRANSITION;
CURRENT PATTERNS; VORTICES; DISORDER; CURRENTS; FIELD; LINE
AB Using a differential magneto-optical technique to visualize the flow of transport currents, we reveal a new delocalization line within the reversible vortex liquid region in the presence of a low density of columnar defects. This line separates a homogeneous vortex liquid, in which all the vortices are delocalized, from a heterogeneous "nanoliquid" phase, in which interconnected nanodroplets of vortex liquid are caged in the pores of a solid skeleton formed by vortices pinned on columnar defects. The nanoliquid phase displays high correlation along the columnar defects but no transverse critical current.
C1 Weizmann Inst Sci, Dept Condensed Matter Phys, IL-76100 Rehovot, Israel.
CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA.
Inst Balseiro, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina.
Comis Nacl Energia Atom, Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina.
Ecole Polytech, Solides Irradies Lab, CNRS, UMR 7642, F-91128 Palaiseau, France.
Ecole Polytech, CEA, CMS, DRECAM, F-91128 Palaiseau, France.
Univ Tokyo, Dept Appl Phys, Bunkyo Ku, Tokyo 1138656, Japan.
Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA.
RP Weizmann Inst Sci, Dept Condensed Matter Phys, IL-76100 Rehovot, Israel.
RI Tamegai, Tsuyoshi /C-6656-2011; Soibel, Alexander/A-1313-2007; Zeldov,
Eli/K-1546-2012
NR 31
TC 32
Z9 32
U1 1
U2 4
PU AMER PHYSICAL SOC
PI COLLEGE PK
PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA
SN 0031-9007
EI 1079-7114
J9 PHYS REV LETT
JI Phys. Rev. Lett.
PD AUG 27
PY 2004
VL 93
IS 9
AR 097002
DI 10.1103/PhysRevLett.93.097002
PG 4
WC Physics, Multidisciplinary
SC Physics
GA 849QS
UT WOS:000223555600053
PM 15447129
ER
PT J
AU Li, ZQ
Wiscombe, W
Stephens, GL
Ackerman, TP
AF Li, ZQ
Wiscombe, W
Stephens, GL
Ackerman, TP
TI Disagreements over cloud absorption - Response
SO SCIENCE
LA English
DT Letter
C1 Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA.
Univ Maryland, ESSIC, College Pk, MD 20742 USA.
Chinese Acad Sci, Inst Atmospher Phys, Beijing 100864, Peoples R China.
NASA, Climate & Radiat Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA.
Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA.
Pacific NW Natl Lab, Atmospher Radiat Measurement Program, Richland, WA 99352 USA.
RP Li, ZQ (reprint author), Univ Maryland, Dept Meteorol, 2207 CSS Bldg, College Pk, MD 20742 USA.
RI Wiscombe, Warren/D-4665-2012; Li, Zhanqing/F-4424-2010
OI Wiscombe, Warren/0000-0001-6844-9849; Li, Zhanqing/0000-0001-6737-382X
NR 5
TC 3
Z9 3
U1 0
U2 4
PU AMER ASSOC ADVANCEMENT SCIENCE
PI WASHINGTON
PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA
SN 0036-8075
J9 SCIENCE
JI Science
PD AUG 27
PY 2004
VL 305
IS 5688
BP 1240
EP 1240
PG 1
WC Multidisciplinary Sciences
SC Science & Technology - Other Topics
GA 850PJ
UT WOS:000223624600019
ER
PT J
AU Knaepen, B
Kassinos, S
Carati, D
AF Knaepen, B
Kassinos, S
Carati, D
TI Magnetohydrodynamic turbulence at moderate magnetic Reynolds number
SO JOURNAL OF FLUID MECHANICS
LA English
DT Article
ID MHD TURBULENCE; NUMERICAL-SIMULATION; FIELD; TENSORS
AB We consider the case of homogeneous turbulence in a conducting fluid that is exposed to a uniform external magnetic field at low to moderate magnetic Reynolds numbers (by moderate we mean here values as high as 20). When the magnetic Reynolds number is vanishingly small (R-m much less than 1), it is customary to simplify the governing magnetohydrodynamic (MHD) equations using what is known as the quasi-static (QS) approximation. As the magnetic Reynolds number is increased, a progressive transition between the physics described by the QS approximation and the MHD equations occurs. We show here that this intermediate regime can be described by another approximation which we call the quasi-linear (QL) approximation. For the numerical simulations performed, the predictions of the QL approximation are in good agreement with those of MHD for magnetic Reynolds number up to R-m similar to 20.
C1 Stanford Univ, NASA, Ames Res Ctr, Ctr Turbulence Res, Stanford, CA 94305 USA.
Univ Libre Brussels, B-1050 Brussels, Belgium.
Univ Cyprus, Dept Mech & Mfg Engn, CY-1678 Nicosia, Cyprus.
RP Knaepen, B (reprint author), Stanford Univ, NASA, Ames Res Ctr, Ctr Turbulence Res, Stanford, CA 94305 USA.
RI Kassinos, Stavros/B-6404-2016
OI Kassinos, Stavros/0000-0002-3501-3851
NR 17
TC 41
Z9 41
U1 0
U2 0
PU CAMBRIDGE UNIV PRESS
PI NEW YORK
PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA
SN 0022-1120
EI 1469-7645
J9 J FLUID MECH
JI J. Fluid Mech.
PD AUG 25
PY 2004
VL 513
BP 199
EP 220
DI 10.1017/S0022112004000023
PG 22
WC Mechanics; Physics, Fluids & Plasmas
SC Mechanics; Physics
GA 857JM
UT WOS:000224112500009
ER
PT J
AU Sanchez, B
Haberle, R
Schaeffer, J
AF Sanchez, B
Haberle, R
Schaeffer, J
TI Atmospheric rotational effects on Mars based on the NASA Ames general
circulation model: Angular momentum approach
SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
LA English
DT Article
DE atmospheric model; Mars; rotation
ID MARTIAN ATMOSPHERE; EXCHANGE; FIELD; CORE; CAPS
AB The NASA Ames general circulation model has been used to compute time series for atmospheric products of inertia and relative angular momentum terms. Model outputs were used also to compute time series representing the inertia terms due to CO2 condensation and sublimation on the surface of Mars. Some of these terms were used to generate time series representing the forcing functions for the equatorial components of the linearized Liouville equations of rotational motion. These equations were then solved numerically for a period of a Martian year (669 sols) to obtain a time series for the position of the rotation pole on the surface of Mars. The results of the investigation indicate that mass variation in the atmosphere is as important as the formation and sublimation of ice caps on the surface of the planet. Numerical integration of the equations of rotational motion yields pole displacements as large as 30.9 cm (ice caps solution), 39.5 cm (atmospheric effects), or 33 cm (both effects combined). Fourier analysis of the time series corresponding to the equatorial components of pole displacement for the ice caps solution as well as the atmospheric effects solution shows that the (1/3)-annual harmonic has the largest coefficient in three cases, with magnitudes in the 7-9 cm range. Fourier analysis of the equatorial components of polar motion for the combined solution yields main harmonics of 5.12 cm (x), (1/3)-annual and 7.50 cm (y), annual.
C1 NASA, Goddard Space Flight Ctr, Terr Phys Lab, Geodynam Branch, Greenbelt, MD 20771 USA.
RP Sanchez, B (reprint author), NASA, Goddard Space Flight Ctr, Terr Phys Lab, Geodynam Branch, Code 921, Greenbelt, MD 20771 USA.
EM braulio.v.sanchez@nasa.gov
NR 18
TC 10
Z9 10
U1 0
U2 0
PU AMER GEOPHYSICAL UNION
PI WASHINGTON
PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA
SN 0148-0227
J9 J GEOPHYS RES-PLANET
JI J. Geophys. Res.-Planets
PD AUG 24
PY 2004
VL 109
IS E8
AR E08005
DI 10.1029/2004JE002254
PG 11
WC Geochemistry & Geophysics
SC Geochemistry & Geophysics
GA 850MS
UT WOS:000223616600002
ER
EF