FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Burlaga, LF Vinas, AF AF Burlaga, LF Vinas, AF TI Multiscale structure of the magnetic field and speed at 1 AU during the declining phase of solar cycle 23 described by a generalized Tsallis probability distribution function SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE magnetic field; multiscale solar wind; plasma; Tsallis distribution ID ANOMALOUS SCALING LAWS; HIGH REYNOLDS-NUMBER; SOLAR-WIND; INTERMITTENT TURBULENCE; MULTIFRACTAL STRUCTURE; VELOCITY FLUCTUATIONS; RECURRENT STREAMS; 1-AU; PLASMA; STATISTICS AB This paper describes the multiscale structure of fluctuations in the solar wind speed V and magnetic field strength B at 1 AU in 2003, during the declining phase of the solar cycle 23. As expected, there was a corotating stream and a corotating interaction region (CIR) that recurred every 27 days, but the stream and CIR changed considerably from one solar rotation to the next. There were also other types of physical structures ( intermittent turbulence at the smallest scales, compound streams and ejecta at intermediate scales, and the collection of streams and ejecta of different sizes and shapes at the largest scales). A multiscale description of these fluctuations is more appropriate than a model of a recurrent stream with small-scale fluctuations superimposed. The probability distribution functions (PDFs) of changes of V and B on scales from 1 hour to approximate to171 days can be described by a generalization of the PDF derived by Tsallis from a nonadditive entropy function in the context of nonextensive statistical mechanics. C1 NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Burlaga, LF (reprint author), NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Mail Code 692,Bldg 21,Rm 244, Greenbelt, MD 20771 USA. EM leonard.f.burlaga@nasa.gov NR 47 TC 37 Z9 38 U1 0 U2 1 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 DEC 21 PY 2004 VL 109 IS A12 AR A12107 DI 10.1029/2004JA0010763 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 883QD UT WOS:000226028500001 ER PT J AU Bielewicz, P Gorski, KM Banday, AJ AF Bielewicz, P Gorski, KM Banday, AJ TI Low-order multipole maps of cosmic microwave background anisotropy derived from WMAP SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE cosmic microwave background; cosmology : observations ID DMR SKY MAPS; FOREGROUND CONTAMINATION; PRIMORDIAL INHOMOGENEITY; POWER SPECTRUM; DUST EMISSION; PROBE DATA; RADIATION; QUADRUPOLE; RADIOMETER; TEMPLATE AB Recent analyses of the Wilkinson Microwave Anisotropy Probe (WMAP) data have suggested that the low-order multipoles of the cosmic microwave background (CMB) anisotropy distribution show cosmologically interesting and unexpected morphologies and amplitudes. In this paper, we apply a power equalization (PE) filter to the high-latitude WMAP data in order to reconstruct these low-multipoles free from the largest Galactic foreground modelling uncertainties in the Galactic plane. The characteristic spatial distributions of the modes of order l = 2, 3, 4, 5 have been determined as a function of frequency, sky coverage and two methods for foreground correction: using the template-based corrections of Bennett et al. and by a simple linear projection scheme assuming the spectral dependence of the foreground components. Although the derived multipole maps are statistically consistent with previous estimates from Tegmark, de Oliveira-Costa & Hamilton (TOH) and Efstathiou, our analyses suggest that the K and Ka frequency bands remain significantly contaminated by residual foreground emission for the WMAP Kp2 mask. However, the = 3, 4, 5 multipole maps for the Q, V and W channels indicate that, after foreground cleaning, these multipoles are dominated by the CMB anisotropy component. We confirm the TOH result that the octopole does indeed show structure in which its hot and cold spots are centred on a single plane in the sky, and show further that this is very stable with respect to the applied mask and foreground correction. The estimated quadrupole is much less stable showing non-negligible dependence on the Galactic foreground correction. Including these uncertainties is likely to weaken the statistical significance of the claimed alignment between the quadrupole and octopole. Nevertheless, these anisotropy patterns are also present in the COBE-DMR data and are unlikely to be associated with instrumental systematic artefacts. C1 Univ Warsaw, Inst Theoret Phys, PL-00681 Warsaw, Poland. Univ Warsaw Observ, PL-00478 Warsaw, Poland. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Max Planck Inst Astrophys, D-85741 Garching, Germany. RP Bielewicz, P (reprint author), Univ Warsaw, Inst Theoret Phys, Ul Hoza 69, PL-00681 Warsaw, Poland. EM pbielew@fuw.edu.pl NR 44 TC 73 Z9 73 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 DEC 21 PY 2004 VL 355 IS 4 BP 1283 EP 1302 DI 10.1111/j.1365-2966.2004.08405.x PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 878GZ UT WOS:000225636100025 ER PT J AU Krug, AZ Patzkowsky, ME AF Krug, AZ Patzkowsky, ME TI Rapid recovery from the Late Ordovician mass extinction SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE diversity; Silurian ID TRILOBITE ALPHA-DIVERSITY; FOSSIL RECORD; TAXONOMIC DIVERSITY; BIODIVERSITY; RADIATION; PALEOBIODIVERSITY; DIVERSIFICATION; PATTERNS; LIFE; BIAS AB Understanding the evolutionary role of mass extinctions requires detailed knowledge of postextinction recoveries. However, most models of recovery hinge on a direct reading of the fossil record, and several recent studies have suggested that the fossil record is especially incomplete for recovery intervals immediately after mass extinctions. Here, we analyze a database of genus occurrences for the paleocontinent of Laurentia to determine the effects of regional processes on recovery and the effects of variations in preservation and sampling intensity on perceived diversity trends and taxonomic rates during the Late Ordovician mass extinction and Early Silurian recovery. After accounting for variation in sampling intensity, we find that marine benthic diversity in Laurentia recovered to preextinction levels within 5 million years, which is nearly 15 million years sooner than suggested by global compilations. The rapid turnover in Laurentia suggests that processes such as immigration may have been particularly important in the recovery of regional ecosystems from environmental perturbations. However, additional regional studies and a global analysis of the Late Ordovician mass extinction that accounts for variations in sampling intensity are necessary to confirm this pattern. Because the record of Phanerozoic mass extinctions and postextinction recoveries may be compromised by variations in preservation and sampling intensity, all should be reevaluated with sampling-standardized analyses if the evolutionary role of mass extinctions is to be fully understood. C1 Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. Penn State Univ, Natl Aeronaut & Space Adm, Astrobiol Inst, University Pk, PA 16802 USA. RP Krug, AZ (reprint author), Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. EM akrug@geosc.psu.edu NR 56 TC 26 Z9 27 U1 1 U2 13 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 DEC 21 PY 2004 VL 101 IS 51 BP 17605 EP 17610 DI 10.1073/pnas.0405199102 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 882PT UT WOS:000225951500009 PM 15596725 ER PT J AU Dorrington, AA Jones, TW Danehy, PM AF Dorrington, AA Jones, TW Danehy, PM TI Photophysics of laser dye-doped polymer membranes for laser-induced fluorescence photogrammetry SO APPLIED OPTICS LA English DT Article ID EMISSION AB Laser-induced fluorescence target generation in dye-doped polymer films has recently been introduced as a promising alternative to more traditional photogrammetric targeting techniques for surface profiling of highly transparent or reflective membrane structures. We investigate the photophysics of these dye-doped polymers to help determine their long-term durability and suitability for laser-induced fluorescence photogrammetric targeting. These investigations included experimental analysis of the fluorescence emission pattern, spectral content, temporal lifetime, linearity, and half-life. Results are presented that reveal an emission pattern than normal Lambertian diffuse surface scatter, a fluorescence time constant of 6.6 ns, a pump saturation level of approximately 20 muJ/mm(2), and a useful lifetime of more than 300,000 measurements. Furthermore. two demonstrations of photogrammetric measurements by laser-induced fluorescence targeting are presented. showing agreement between. photogrammetric and physically measured dimensions within the measurement scatter of 100 mum. (C) 2004 Optical Society of America. C1 Univ Waikato, Dept Phys & Elect Engn, Hamilton, New Zealand. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Dorrington, AA (reprint author), Univ Waikato, Dept Phys & Elect Engn, Private Bag 3105, Hamilton, New Zealand. EM a.dorrington@waikato.ac.nz NR 19 TC 2 Z9 2 U1 1 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 DEC 20 PY 2004 VL 43 IS 36 BP 6629 EP 6638 DI 10.1364/AO.43.006629 PG 10 WC Optics SC Optics GA 882CP UT WOS:000225916500010 PM 15646782 ER PT J AU Dawson, S Rhoads, JE Malhotra, S Stern, D Dey, A Spinrad, H Jannuzi, BT Wang, JX Landes, E AF Dawson, S Rhoads, JE Malhotra, S Stern, D Dey, A Spinrad, H Jannuzi, BT Wang, JX Landes, E TI Spectroscopic properties of the z approximate to 4.5 Ly alpha emitters SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : high-redshift ID HUBBLE-DEEP-FIELD; STAR-FORMING GALAXIES; LYMAN BREAK GALAXIES; HIGH-REDSHIFT; POPULATION-III; LUMINOSITY FUNCTION; STARBURST GALAXIES; YOUNG GALAXIES; 1ST STARS; EMISSION AB We present Keck Low Resolution Imaging Spectrometer optical spectra of 17 Lyalpha-emitting galaxies and one Lyman break galaxy at z approximate to 4.5 discovered in the Large Area Lyman Alpha survey. The survey has identified a sample of similar to 350 candidate Lyalpha-emitting galaxies at z approximate to 4.5 in a search volume of 1.5 x 10(6) comoving Mpc(3). We targeted 25 candidates for spectroscopy; hence, the 18 confirmations presented herein suggest a selection reliability of 72%. The large equivalent widths (median W-lambda(rest) approximate to 80 Angstrom) but narrow physical widths (Deltav < 500 km s(-1)) of the Lyα emission lines, along with the lack of accompanying high - ionization state emission lines, suggest that these galaxies are young systems powered by star formation rather than by active galactic nucleus activity. Theoretical models of galaxy formation in the primordial universe suggest that a small fraction of Lyα-emitting galaxies at z &AP; 4.5 may still be nascent, metal-free objects. Indeed, we find with 90% confidence that three to five of the confirmed sources show W-λ(rest) > 240 Angstrom, exceeding the maximum Lyalpha equivalent width predicted for normal stellar populations. Nonetheless, we find no evidence for He II lambda1640 emission in either individual or composite spectra, indicating that although these galaxies are young, they are not truly primitive, Population III objects. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Kitt Peak Natl Observ, Natl Opt Astron Observ, Tucson, AZ 85726 USA. Univ Sci & Technol China, Ctr Astrophys, Hefei 230026, Anhui, Peoples R China. RP Dawson, S (reprint author), Univ Calif Berkeley, Dept Astron, Mail Code 3411, Berkeley, CA 94720 USA. EM sdawson@astro.berkeley.edu; rhoads@stsci.edu; san@stsci.edu; stern@zwolfkinder.jpl.nasa.gov; dey@noao.edu; spinrad@astro.berkeley.edu; jannuzi@noao.edu; elandes@astro.berkeley.edu NR 60 TC 111 Z9 112 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 DEC 20 PY 2004 VL 617 IS 2 BP 707 EP 717 DI 10.1086/425572 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 882VS UT WOS:000225968200002 ER PT J AU Benson, BA Church, SE Ade, PAR Bock, JJ Ganga, KM Henson, CN Thompson, KL AF Benson, BA Church, SE Ade, PAR Bock, JJ Ganga, KM Henson, CN Thompson, KL TI Measurements of Sunyaev-Zel'dovich effect scaling relations for clusters of galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : observations; galaxies : clusters : general; large-scale structure of universe ID X-RAY-PROPERTIES; PECULIAR VELOCITIES; INTRACLUSTER GAS; TEMPERATURE RELATION; LUMINOUS CLUSTERS; DISTANT CLUSTERS; HUBBLE CONSTANT; COOLING FLOWS; CONSTRAINTS; MASS AB We present new measurements of the Sunyaev-Zel'dovich (SZ) effect from clusters of galaxies using the second-generation Sunyaev-Zel'dovich Infrared Experiment (SuZIE II). We combine these new measurements with previous cluster observations with the SuZIE instrument to form a sample of 15 clusters of galaxies. For this sample we calculate the central Comptonization y(0) and the integrated SZ flux decrement S for each of our clusters. We find that the integrated SZ flux is a more robust observable derived from our measurements than the central Comptonization because of inadequacies in the spatial modeling of the intracluster gas with a standard beta-model. This is highlighted by comparing our central Comptonization results with values calculated from measurements using the BIMA and OVRO interferometers. On average, the SuZIE-calculated central Comptonizations are similar to 60% higher in the cooling flow clusters than the interferometric values, compared to only similar to 12% higher in the non - cooling flow clusters. We believe this discrepancy to be in large part due to the spatial modeling of the intracluster gas. From our cluster sample we construct y(0)- T and S-T scaling relations. The y0- T scaling relation is inconsistent with what we would expect for self-similar clusters; however, this result is questionable because of the large systematic uncertainty in y(0). The S-T scaling relation has a slope and redshift evolution consistent with what we expect for self-similar clusters, with a characteristic density that scales with the mean density of the universe. We rule out zero-redshift evolution of the S-T relation at similar to90% confidence. C1 Stanford Univ, Stanford, CA 94305 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Wales Coll Cardiff, Dept Phys & Astron, Cardiff CF24 3YB, S Glam, Wales. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. RP Benson, BA (reprint author), Stanford Univ, 382 Via Pueblo,Varian Bldg, Stanford, CA 94305 USA. EM bbenson@bolo.berkeley.edu NR 49 TC 65 Z9 65 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 DEC 20 PY 2004 VL 617 IS 2 BP 829 EP 846 DI 10.1086/425677 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 882VS UT WOS:000225968200009 ER PT J AU Markowitz, A Edelson, R AF Markowitz, A Edelson, R TI An expanded Rossi X-Ray Timing Explorer survey of X-ray variability in Seyfert 1 galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : Seyfert; X-rays : galaxies ID ACTIVE GALACTIC NUCLEI; BLACK-HOLE MASS; NARROW-LINE; SPECTRAL VARIABILITY; ASCA OBSERVATIONS; XMM-NEWTON; CONTINUUM VARIABILITY; COLD MATTER; LONG; EMISSION AB The first seven years of RXTE monitoring of Seyfert 1 active galactic nuclei have been systematically analyzed to yield five homogeneous samples of 2 - 12 keV light curves, probing hard X-ray variability on successively longer durations from similar to1 day to similar to3.5 yr. The 2 - 10 keV variability on timescales of similar to1 day, as probed by ASCA, is included. All sources exhibit stronger X-ray variability toward longer timescales, but the increase is greater for relatively higher luminosity sources. Variability amplitudes are anticorrelated with X-ray luminosity and black hole mass, but amplitudes saturate and become independent of luminosity or black hole mass toward the longest timescales. The data are consistent with the models of power spectral density (PSD) movement described by Markowitz and coworkers and McHardy and coworkers, whereby Seyfert 1 galaxies' variability can be described by a single, universal PSD shape whose break frequency scales with black hole mass. The best-fitting scaling relations between variability timescale, black hole mass, and X-ray luminosity imply an average accretion rate of similar to 5% of the Eddington limit for the sample. Nearly all sources exhibit stronger variability in the relatively soft 2 - 4 keV band compared to the 7 - 12 keV band on all timescales. There are indications that relatively less luminous or less massive sources exhibit a greater degree of spectral variability for a given increase in overall flux. C1 NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Dept Astron, Los Angeles, CA 90095 USA. RP Markowitz, A (reprint author), NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. EM agm@milkyway.gsfc.nasa.gov NR 62 TC 63 Z9 63 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 DEC 20 PY 2004 VL 617 IS 2 BP 939 EP 965 DI 10.1086/425559 PN 1 PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 882VS UT WOS:000225968200018 ER PT J AU Pravdo, SH Shaklan, SB Henry, T Benedict, GF AF Pravdo, SH Shaklan, SB Henry, T Benedict, GF TI Astrometric discovery of GJ 164B SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrometry; stars : individual (GJ 164B); stars : low-mass, brown dwarfs ID STAR SPECTROSCOPIC SURVEY; MASS-LUMINOSITY-RELATION; SOLAR NEIGHBORHOOD; PROPER-MOTION; TRIPLE SYSTEM; NEARBY STARS; DWARFS; TELESCOPE; CATALOG; SKY AB We discovered a low-mass companion to the M dwarf GJ 164 with the CCD-based imaging system of the Stellar Planet Survey astrometric program. The existence of GJ 164B was confirmed with Hubble Space Telescope NICMOS imaging observations. A high-dispersion spectral observation in V sets a lower limit of Deltam > 2.2 mag between the two components of the system. Based on our parallax value of 82 +/- 8 mas, we derive the following orbital parameters: P = 2.04 +/- 0.03 yr, a = 103 +/- 0.03, and M-total 0.265 +/- 0.020 M-circle dot. The component masses are M-A = 0.170 +/- 0.015 M-circle dot and M-B = 0.095 +/- 0/015 M-circle dot. Based on its mass, colors, and spectral properties, GJ 164B has spectral type M6-M8 V. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30302 USA. Univ Texas, McDonald Observ, Austin, TX 78712 USA. RP Pravdo, SH (reprint author), CALTECH, Jet Prop Lab, MS 306-431,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM spravdo@jpl.nasa.gov; shaklan@huey.jpl.nasa.gov; thenry@chara.gsu.edu; fritz@astro.as.utexas.edu NR 30 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 DEC 20 PY 2004 VL 617 IS 2 BP 1323 EP 1329 DI 10.1086/425653 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 882VS UT WOS:000225968200047 ER PT J AU Zubko, V Li, D Lim, T Feuchtgruber, H Harwit, M AF Zubko, V Li, D Lim, T Feuchtgruber, H Harwit, M TI Observations of water vapor outflow from NML Cygnus (vol 610, pg 427, 2004) SO ASTROPHYSICAL JOURNAL LA English DT Correction C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Max Planck Inst Extraterr Phys, Garching, Germany. Cornell Univ, Ithaca, NY 14853 USA. RP Zubko, V (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 1 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 DEC 20 PY 2004 VL 617 IS 2 BP 1371 EP 1371 DI 10.1086/425655 PN 1 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 882VS UT WOS:000225968200052 ER PT J AU Ardila, DR Golimowski, DA Krist, JE Clampin, M Williams, JP Blakeslee, JP Ford, HC Hartig, GF Illingworth, GD AF Ardila, DR Golimowski, DA Krist, JE Clampin, M Williams, JP Blakeslee, JP Ford, HC Hartig, GF Illingworth, GD TI A resolved debris disk around the G2 V star HD 107146 SO ASTROPHYSICAL JOURNAL LA English DT Article DE planetary systems : formation; planetary systems : protoplanetary disks; stars : imaging; stars : individual (HD 107146) ID KUIPER-BELT; CIRCUMSTELLAR DISK; AU-MICROSCOPII; GIANT PLANETS; DUST; MIGRATION; ORIGIN AB We present resolved scattered-light images of the debris disk around HD 107146, a G2 star 28.5 pc from the Sun. This is the first debris disk to be resolved in scattered light around a solar-type star. We observed it with the Hubble Space Telescope/Advanced Camera for Surveys coronagraph, using a 1."8 occulting spot and the F606W (broad V) and F814W (broad I) filters. Within 2" from the star, the image is dominated by point-spread function subtraction residuals. Outside this limit, the disk looks featureless, except for a northeast-southwest brightness asymmetry that we attribute to forward scattering. The disk has scattered-light fractional luminosities of (L-sca/L-*)(F606W)=(6.8+/-0.8)x10(-5) and (L-sca/L-*)(F814W)=(10+/-1)x10(-5), and it is detected up to 6."5 away from the star. To map the surface density of the disk, we deproject it by, divide by 25degrees+/-5degrees the dust-scattering phase (g(F606W)=0.3+/-0.1, g(F814W)=0.2+/-0.1), and correct for the geometric dilution of starlight. Within the errors, the surface density has the same shape in each bandpass, and it appears to be a broad (85 AU) ring with most of the opacity concentrated at 130 AU. The ratio of the relative luminosity in F814W to that in F606W has the constant value of 1.3+/-0.3, with the error dominated by uncertainties in the value of g in each filter. An examination of far-infrared and submillimeter measurements suggests the presence of small grains. The colors and the derived values of g are consistent with the presence of dust particles smaller than the radiation pressure limit. Possible scenarios that may explain the shape of the surface density profile are the creation of a small planet or the scattering and circularization of a large one. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. RP Ardila, DR (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. RI Williams, Jonathan/B-1643-2009; Clampin, mark/D-2738-2012; OI Williams, Jonathan/0000-0001-5058-695X; Blakeslee, John/0000-0002-5213-3548 NR 21 TC 51 Z9 51 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 DEC 20 PY 2004 VL 617 IS 2 BP L147 EP L150 DI 10.1086/427434 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 882VT UT WOS:000225968400014 ER PT J AU O'Dwyer, IJ Eriksen, HK Wandelt, BD Jewell, JB Larson, DL Gorski, KM Banday, AJ Levin, S Lilje, PB AF O'Dwyer, IJ Eriksen, HK Wandelt, BD Jewell, JB Larson, DL Gorski, KM Banday, AJ Levin, S Lilje, PB TI Bayesian power spectrum analysis of the first-year Wilkinson Microwave Anisotropy Probe data SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : observations; methods : numerical ID WMAP OBSERVATIONS; MAPS AB We present the first results from a Bayesian analysis of the Wilkinson Microwave Anisotropy Probe (WMAP) first-year data using a Gibbs sampling technique. Using two independent, parallel supercomputer codes, we analyze the WMAP Q, V, and W bands. The analysis results in a full probabilistic description of the information the WMAP data set contains about the power spectrum and the all-sky map of the cosmic microwave background anisotropies. We present the complete probability distributions for each C-l, including any non-Gaussianities of the power spectrum likelihood. While we find good overall agreement with the previously published WMAP spectrum, our analysis uncovers discrepancies in the power spectrum estimates at low-l multipoles. For example, we claim that the best-fit LambdaCDM model is consistent with the C-2 inferred from our combined Q+V+W analysis, with a 10% probability of an even larger theoretical C-2. Based on our exact analysis, we can therefore attribute the "low-quadrupole issue" to a statistical fluctuation. C1 Univ Illinois, Dept Astron, Urbana, IL 61801 USA. Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Univ Oslo, Ctr Math Applicat, N-0316 Oslo, Norway. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Warsaw Observ, PL-00478 Warsaw, Poland. Max Planck Inst Astrophys, D-85741 Garching, Germany. RP O'Dwyer, IJ (reprint author), Univ Illinois, Dept Astron, 1002 W Green St, Urbana, IL 61801 USA. RI Lilje, Per/A-2699-2012; OI WANDELT, Benjamin/0000-0002-5854-8269; Lilje, Per/0000-0003-4324-7794 NR 15 TC 53 Z9 53 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 DEC 20 PY 2004 VL 617 IS 2 BP L99 EP L102 DI 10.1086/427386 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 882VT UT WOS:000225968400002 ER PT J AU Kharuk, VI Ranson, KJ Kozuhovskaya, AG Kondakov, YP Pestunov, IA AF Kharuk, VI Ranson, KJ Kozuhovskaya, AG Kondakov, YP Pestunov, IA TI NOAA/AVHRR satellite detection of Siberian silkmoth outbreaks in eastern Siberia SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID DEFOLIATION AB During 1993-1996, in central Siberia, a silkmoth (Dendrolimus superans sibiricus Tschetw.) infestation damaged approximately 700 000 ha of fir, Siberian pine and spruce stands. Temporal (1995-1997) Advanced Very High Resolution Radiometer (AVHRR) images were used for pest outbreak monitoring of this event. Damaged stands were detected, with heavy (50-75% dead and dying trees) plus very heavy (>75%) levels of damage classified. Summer and winter images were used for delineation of the northern border of the region of pest outbreaks. The Siberian taiga insects were classified with respect to their harmfulness to forests, based on the frequency Of Outbreaks, the size of the damaged territory, and the available food sources based on forest type. C1 Sukachev Inst Forest, Krasnoyarsk, Russia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kharuk, VI (reprint author), Sukachev Inst Forest, Krasnoyarsk, Russia. EM kharuk@ksc.krasn.ru RI Ranson, Kenneth/G-2446-2012 OI Ranson, Kenneth/0000-0003-3806-7270 NR 13 TC 18 Z9 21 U1 2 U2 11 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 DEC 20 PY 2004 VL 25 IS 24 BP 5543 EP 5555 DI 10.1080/01431160410001719858 PG 13 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 878ZW UT WOS:000225687200002 ER PT J AU Campbell, PKE Rock, BN Martin, ME Neefus, CD Irons, JR Middleton, EM Albrechtova, J AF Campbell, PKE Rock, BN Martin, ME Neefus, CD Irons, JR Middleton, EM Albrechtova, J TI Detection of initial damage in Norway spruce canopies using hyperspectral airborne data SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID NEAR-INFRARED REFLECTANCE; CHLOROPHYLL-A; FOREST DAMAGE; RED EDGE; SPECTRAL MEASUREMENTS; UNITED-STATES; LEAVES; ANISOTROPY; NITROGEN; INDEX AB Current broadband sensors are not capable of separating the initial stages of forest damage. The current investigation evaluates the potential of hyperspectrall data for detecting the initial stages of forest damage at the canopy level in the Norway spruce (Picea abies (L.) Karst) forests of Czech Republic. Hyperspectral canopy reflectance imagery and foliar samples were acquired contemporaneously for 23 study sites in August 1998. The sites were selected along an air pollution gradient to represent the full range of damage conditions in even-aged spruce forests. The changes in canopy and foliar reflectance, chemistry and pigments associated with forest damage were established. The potential of a large number of spectral indices to identify initial forest damage was determined. Canopy hyperspectral data were able to separate healthy from initially damaged canopies, and therefore provided an improved capability for assessment of forest physiology as compared to broadband systems. The 673-724 nm region exhibited maximum sensitivity to initial damage. The nine spectral indices having the highest potential as indicators of the initial damage included: three simple band ratios, two derivative indices, two modelled red-edge parameters and two normalized bands. The sensitivity of these indices to damage was explained primarily by their relationship to foliar structural chemical compounds, which differed significantly by damage class. C1 Univ New Hampshire, Complex Syst Res Ctr, Durham, NH 03824 USA. Univ New Hampshire, Dept Plant Biol, Durham, NH 03824 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Charles Univ, Dept Plant Physiol, CR-12844 Prague 2, Czech Republic. RP Campbell, PKE (reprint author), NASA, Goddard Space Flight Ctr, Code 923, Greenbelt, MD 20771 USA. EM pcampbel@pop900.gsfc.nasa.gov RI Campbell, Petya/A-9649-2008; Irons, James/D-8535-2012; Campbell, Petya/G-4931-2013; Campbell, Petya/L-7486-2013; OI Campbell, Petya/0000-0002-0505-4951; Campbell, Petya/0000-0002-0505-4951; Albrechtova, Jana/0000-0001-6912-1992 NR 61 TC 27 Z9 27 U1 0 U2 17 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 DEC 20 PY 2004 VL 25 IS 24 BP 5557 EP 5583 DI 10.1080/01431160410001726058 PG 27 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 878ZW UT WOS:000225687200003 ER PT J AU Masek, JG Sun, G AF Masek, JG Sun, G TI A spectral-angle methodology for mapping net forest cover change in northeastern China SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID LAND-COVER; SYSTEM AB As part of the Global Observations of Forest Cover/Land Cover Dynamics (GOFC-GOLD) project, forest-cover change in northeastern China is being mapped using Landsat-5 and Landsat-7 imagery. This technical note details some of the challenges associated with mapping net forest-cover conversion in the region, and presents a new algorithm that overcomes some of these challenges, The mapping approach uses the concept of spectral angle to establish change between images, and implements spectral thresholds to determine the type of change. Validation results give an overall accuracy of 84-96% and a detection accuracy of 72-83%. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Geog, College Pk, MD 20742 USA. RP Masek, JG (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM Jeffrey.G.Masek@nasa.gov RI Masek, Jeffrey/D-7673-2012 NR 18 TC 2 Z9 2 U1 0 U2 2 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 DEC 20 PY 2004 VL 25 IS 24 BP 5629 EP 5636 DI 10.1080/01431160410001709066 PG 8 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 878ZW UT WOS:000225687200007 ER PT J AU Dorelli, JC Hesse, M Kuznetsova, MM Rastaetter, L Raeder, J AF Dorelli, JC Hesse, M Kuznetsova, MM Rastaetter, L Raeder, J TI A new look at driven magnetic reconnection at the terrestrial subsolar magnetopause SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE magnetic reconnection; magnetopause; magnetic flux pileup; global MHD simulation; GGCM ID PILE-UP RECONNECTION; HYBRID DRIFT INSTABILITY; COLLISIONLESS RECONNECTION; CURRENT SHEET; DAYSIDE MAGNETOPAUSE; STAGNATION-POINT; PLASMA DEPLETION; STEADY-STATE; CHALLENGE; FLOWS AB The physics of steady driven magnetic reconnection at Earth's subsolar magnetopause is addressed. Three-dimensional, global magnetohydrodynamics (MHD) simulations of the magnetopause are compared with analytical solutions of the resistive MHD equations [Sonnerup and Priest, 1975] corresponding to magnetic field annihilation driven by an incompressible stagnation point flow. The simulations demonstrate that under steady southward interplanetary magnetic field conditions and when the plasma resistivity is spatially uniform, subsolar magnetopause reconnection occurs in long, thin Sweet-Parker current sheets via a flux pileup mechanism [Sonnerup and Priest, 1975; Priest and Forbes, 1986] (rather than in Petschek slow shock configurations). Magnetic energy piles up upstream of the magnetopause current sheet to accommodate the sub-Alfvenic solar wind inflow. The scaling of the pileup with Lundquist number, S, is consistent (approximately proportional to S(1/4)) with that predicted by the analytical, incompressible stagnation point flow solutions (though there are small corrections due to plasma compressibility in the simulations). Since there is a finite energy in the magnetosheath available to drive the magnetic pileup (and associated rapid magnetic reconnection), we expect the pileup to saturate and the reconnection rate to drop as the upstream plasma pressure drops to accommodate the pileup. Thus we expect the reconnection to stall, the rate vanishing in the limit S --> infinity. We discuss the role of Hall electric fields in allowing the magnetic pileup to saturate before the reconnection begins to stall, permitting Alfvenic reconnection to occur in thin current sheets in the limit S --> infinity. C1 NASA, Goddard Space Flight Ctr, Community Coordinated Modeling Ctr, Electrodynam Branch,Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. RP Dorelli, JC (reprint author), NASA, Goddard Space Flight Ctr, Community Coordinated Modeling Ctr, Electrodynam Branch,Extraterr Phys Lab, Greenbelt, MD 20771 USA. EM john.dorelli@unh.edu; michael.hesse@gsfc.nasa.gov RI Dorelli, John/C-9488-2012; Hesse, Michael/D-2031-2012; Rastaetter, Lutz/D-4715-2012; Kuznetsova, Maria/F-6840-2012 OI Rastaetter, Lutz/0000-0002-7343-4147; NR 74 TC 18 Z9 18 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-SPACE JI J. Geophys. Res-Space Phys. PD DEC 18 PY 2004 VL 109 IS A12 AR A12216 DI 10.1029/2004JA010458 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 881QV UT WOS:000225884100002 ER PT J AU LeGrande, AN Lynch-Stieglitz, J Farmer, EC AF LeGrande, AN Lynch-Stieglitz, J Farmer, EC TI Oxygen isotopic composition of Globorotalia truncatulinoides as a proxy for intermediate depth density SO PALEOCEANOGRAPHY LA English DT Article DE Globorotalia truncatulinoides; oxygen isotopes; ocean circulation ID PLANKTONIC-FORAMINIFERA; DISSOLUTION; GRADIENTS; ATLANTIC AB We investigate whether the oxygen isotope ratio in the test of Globorotalia truncatulinoides can serve as a proxy for intermediate depth (200-500 m) density. Since intermediate depth horizontal density gradients are associated with the vertical shear of upper ocean flows, this proxy could provide a tool for reconstructing past ocean circulation. The spatial pattern of core top Gr. truncatulinoides delta(18)O in the Atlantic Ocean mimics the upper ocean density gradients associated with the major ocean currents. To better constrain the controls on the calcification depth(s) of Gr. truncatulinoides, we attempt to simulate the surface sediment data set using water column temperature and salinity conditions above the core sites. We predicted foraminiferal delta(18)O for each core site assuming (1) the calcification occurs at a single depth and (2) the initial calcification is at the surface and the subsequent calcification is at 800 m water depth. The predicted delta(18)O best resembles measured delta(18)O of Gr. truncatulinoides when using (1) a single depth calcification at 350 m or (2) a two-depth approximation with 30% surface and 70% 800-m calcification. This result gives us confidence in the ability of delta(18)O in Gr. truncatulinoides to proxy lateral density gradients at the intermediate depths associated with upper ocean flow. C1 Columbia Univ, Dept Earth & Environm Sci, Palisades, NY 10964 USA. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP LeGrande, AN (reprint author), Columbia Univ, Dept Earth & Environm Sci, 61 Route 9W, Palisades, NY 10964 USA. EM legrande@ldeo.columbia.edu RI LeGrande, Allegra/D-8920-2012 OI LeGrande, Allegra/0000-0002-5295-0062 NR 16 TC 19 Z9 19 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0883-8305 J9 PALEOCEANOGRAPHY JI Paleoceanography PD DEC 18 PY 2004 VL 19 IS 4 AR PA4025 DI 10.1029/2004PA001045 PG 7 WC Geosciences, Multidisciplinary; Oceanography; Paleontology SC Geology; Oceanography; Paleontology GA 881QY UT WOS:000225884500003 ER PT J AU Price, MW Scripa, RN Szofran, FR Motakef, S Hanson, B AF Price, MW Scripa, RN Szofran, FR Motakef, S Hanson, B TI Analysis of radial segregation in directionally solidified Hg0.89Mn0.11Te SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE directional solidification; Bridgman technique; semiconducting II-VI materials ID VERTICAL BRIDGMAN METHOD; CRYSTAL-GROWTH; BINARY-ALLOYS; CONVECTION; HGCDTE; HGMNTE; MELTS AB Bridgman growth experiments were performed on Hg0.89Mn0.11Te (MMT) to determine the extent of radial Manganese segregation during directional solidification. MMT crystals were directionally solidified at rates of 0.09 and 0.18 mum/s and in axial thermal gradients of 83 and 68degreesC/cm. Wavelength dispersive spectroscopy and Fourier Transform infra-red analytical techniques were used to determine the radial homogeneity in all boules and the deflection of the solid-liquid interface (SLI) in two boules that were rapidly quenched after 5-6cm of directional solidification. For all growth runs, the measured radial compositional variations were on the order of 0.01 molar percent MnTe in the steady-state region of growth. Comparison of the measured radial compositional results of the crystals to predicted values in the diffusion-limited regime indicate a strong influence of convection near the SLI. This conclusion is supported by the weak influence of the translation rates and axial thermal gradients utilized in this study upon radial compositional homogeneity. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Alabama, Dept Mat Sci & Engn, Birmingham, AL 35294 USA. Corning Inc, Corning, NY 14831 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. CAPE Simulat, Natick, MA USA. RP Scripa, RN (reprint author), Univ Alabama, Dept Mat Sci & Engn, Birmingham, AL 35294 USA. EM rscripa@uab.edu NR 23 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD DEC 17 PY 2004 VL 273 IS 1-2 BP 179 EP 189 DI 10.1016/j.jcrysgro.2004.08.018 PG 11 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 883NX UT WOS:000226021000023 ER PT J AU Numata, K Kemery, A Camp, J AF Numata, K Kemery, A Camp, J TI Thermal-noise limit in the frequency stabilization of lasers with rigid cavities SO PHYSICAL REVIEW LETTERS LA English DT Article ID MECHANICAL LOSS; INTERNAL-FRICTION; COATINGS; SILICA AB We evaluate thermal noise (Brownian motion) in a rigid reference cavity used for frequency stabilization of lasers, based on the mechanical loss of cavity materials and the numerical analysis of the mirror-spacer mechanics with the direct application of the fluctuation dissipation theorem. This noise sets a fundamental limit for the frequency stability achieved with a rigid frequency-reference cavity of order 1 Hz/rootHz (0.01 Hz/rootHz) at 10 mHz (100 Hz) at room temperature. This level coincides with the world-highest level stabilization results. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Numata, K (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 663, Greenbelt, MD 20771 USA. EM numata@milkyway.gsfc.nasa.gov NR 24 TC 256 Z9 260 U1 13 U2 53 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 DEC 17 PY 2004 VL 93 IS 25 AR 250602 DI 10.1103/PhysRevLett.93.250602 PG 4 WC Physics, Multidisciplinary SC Physics GA 880JD UT WOS:000225785200013 PM 15697887 ER PT J AU Goldberg, RA Fritts, DC AF Goldberg, RA Fritts, DC TI Introduction to special section: The MaCWAVE-MIDAS Program to Study the Polar Summer Mesosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Editorial Material C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NW Res Associates Inc, Colorado Res Associates, Boulder, CO 80301 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 NR 0 TC 2 Z9 2 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 DEC 16 PY 2004 VL 31 IS 24 AR L24S01 DI 10.1029/2004GL021789 PG 1 WC Geosciences, Multidisciplinary SC Geology GA 881QE UT WOS:000225882000006 ER PT J AU Edwards, DP Emmons, LK Hauglustaine, DA Chu, DA Gille, JC Kaufman, YJ Petron, G Yurganov, LN Giglio, L Deeter, MN Yudin, V Ziskin, DC Warner, J Lamarque, JF Francis, GL Ho, SP Mao, D Chen, J Grechko, EI Drummond, JR AF Edwards, DP Emmons, LK Hauglustaine, DA Chu, DA Gille, JC Kaufman, YJ Petron, G Yurganov, LN Giglio, L Deeter, MN Yudin, V Ziskin, DC Warner, J Lamarque, JF Francis, GL Ho, SP Mao, D Chen, J Grechko, EI Drummond, JR TI Observations of carbon monoxide and aerosols from the Terra satellite: Northern Hemisphere variability SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE Terra; aerosols; carbon monoxide ID RESOLUTION IMAGING SPECTRORADIOMETER; TROPOSPHERE MOPITT INSTRUMENT; COMMUNITY CLIMATE MODEL; FOREST-FIRES; BOREAL FORESTS; ATMOSPHERIC AEROSOLS; OXIDANTS EXPRESSO; REGIONAL SOURCES; EMISSION FACTORS; NATIONAL CENTER AB Measurements from the Terra satellite launched in December of 1999 provide a global record of the recent interannual variability of tropospheric air quality: carbon monoxide (CO) from the Measurement of Pollution in the Troposphere (MOPITT) instrument and aerosol optical depth (AOD) from the Moderate-Resolution Imaging Spectroradiometer (MODIS). This paper compares and contrasts these data sets with a view to understanding the general features of the overall pollutant loading of the Northern Hemisphere (NH). We present a detailed examination of the seasonal and recent interannual variability of the fine mode AOD and CO column, first considering the variation of the global zonal average for both quantities, and then concentrating on several geographical regions with the aim of isolating different emissions. In a zonal sense, the principal NH sources are related to anthropogenic urban and industrial activity. We show that both the CO and the AOD zonal seasonal variations reflect the atmospheric oxidant concentration, which determines the primary sink of CO and the production of sulfate aerosol. As a consequence, the seasonal cycles are several months out of phase, with perturbations resulting from sporadic wildfire or biomass-burning emissions. In these cases, carbonaceous particles dominate the AOD, and this results in the best correlation with the CO column. Of the 4 years of data available from the Terra satellite, the winter and spring of 2002-2003 showed anomalously high NH pollution compared to the previous years. This was a result of fires in western Russia in the late summer and fall of 2002 and intense fires in the southeast of Russia in the spring and summer of 2003. We examine these events using fire counts from MODIS to indicate the burning regions and investigate how the timing of the fires in relation to atmospheric oxidant concentrations affects the resultant seasonal pollutant loadings. Finally, we trace the emissions from these fires to indicate how intense local pollution sources can impact continental- and global-scale air quality. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Lab Sci Climat & Environm, F-91191 Gif Sur Yvette, France. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Frontier Res Syst Global Change, Kanazawa Ku, Yokohama, Kanagawa 2360001, Japan. Obukhov Inst Atmospher Phys, Moscow 109017, Russia. Univ Toronto, Dept Phys, Toronto, ON M5S 1AS, Canada. RP Edwards, DP (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. EM edwards@ucar.edu; emmons@ucar.edu; hauglustaine@cea.fr; achu@climate.gsfc.nasa.gov; gille@ucar.edu; kaufman@climate.gsfc.nasa.gov; gap@ucar.edu; leonid@jamstec.go.jp; giglio@hades.gsfc.nasa.gov; mnd@ucar.edu; vyudin@ucar.edu; ziskin@ucar.edu; juying@ucar.edu; lamar@ucar.edu; gfrancis@ucar.edu; spho@ucar.edu; dmao@ucar.edu; jschen@ucar.edu; grechko@ifaran.ru; james.drummond@utoronto.ca RI Pfister, Gabriele/A-9349-2008; Lamarque, Jean-Francois/L-2313-2014; Drummond, James/O-7467-2014; Deeter, Merritt/O-6078-2016; Emmons, Louisa/R-8922-2016 OI Lamarque, Jean-Francois/0000-0002-4225-5074; Deeter, Merritt/0000-0002-3555-0518; Emmons, Louisa/0000-0003-2325-6212 NR 59 TC 141 Z9 141 U1 3 U2 30 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 DEC 16 PY 2004 VL 109 IS D24 AR D24202 DI 10.1029/2004JD004727 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 881QI UT WOS:000225882400001 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 (vol 225, pg 279, 2004) SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Correction C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Acad Sci Czech Republic, Inst Geol, Prague, Czech Republic. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Charles Univ Prague, Fac Nat Sci, Dept Appl Geophys, 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; NR 1 TC 1 Z9 1 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X EI 1385-013X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD DEC 15 PY 2004 VL 228 IS 3-4 BP 573 EP 573 DI 10.1016/j.epsl.2004.10.010 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 882JV UT WOS:000225936100027 ER PT J AU Di Girolamo, L Bond, TC Bramer, D Diner, DJ Fettinger, F Kahn, RA Martonchik, JV Ramana, MV Ramanathan, V Rasch, PJ AF Di Girolamo, L Bond, TC Bramer, D Diner, DJ Fettinger, F Kahn, RA Martonchik, JV Ramana, MV Ramanathan, V Rasch, PJ TI Analysis of Multi-angle Imaging SpectroRadiometer (MISR) aerosol optical depths over greater India during winter 2001-2004 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SULFUR-DIOXIDE EMISSIONS; OCEAN EXPERIMENT; INVENTORY; COMBUSTION; AERONET; NETWORK; CARBON; BLACK AB We present the first detailed spatial analysis of a four-year, wintertime visible aerosol optical depth (AOD) climatology from the Multi-angle Imaging SpectroRadiometer (MISR) over greater India. Meteorological fields from the National Centers for Environmental Prediction (NCEP) reanalysis, topographic data, and information related to aerosol source regions are used to explain the spatial patterns in MISR AODs. High AODs are found over much of greater India. The highest AODs are over the northern Indian state of Bihar, where we show that meteorology, topography, and aerosol sources all favor development of a concentrated pool of airborne particles. MISR AODs are validated against five ground-based sites in India and Nepal, revealing similar error characteristics found in other validation studies for the MISR aerosol product. C1 Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. Univ Illinois, Dept Civil & Environm Engn, Urbana, IL 61801 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Scripps Inst Oceanog, Ctr Atmospher Sci, La Jolla, CA 92307 USA. Natl Ctr Atmospher Res, Climat & Global Dynam Div, Boulder, CO 80307 USA. RP Univ Illinois, Dept Atmospher Sci, 105 S Gregory St, Urbana, IL 61801 USA. EM larry@atmos.uiuc.edu RI Bond, Tami/A-1317-2013; Kahn, Ralph/D-5371-2012 OI Bond, Tami/0000-0001-5968-8928; Kahn, Ralph/0000-0002-5234-6359 NR 17 TC 112 Z9 114 U1 0 U2 10 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 DEC 15 PY 2004 VL 31 IS 23 AR L23115 DI 10.1029/2004GL021273 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 881QD UT WOS:000225881900004 ER PT J AU Gopalswamy, N Yashiro, S Krucker, S Stenborg, G Howard, RA AF Gopalswamy, N Yashiro, S Krucker, S Stenborg, G Howard, RA TI Intensity variation of large solar energetic particle events associated with coronal mass ejections SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE CME; flare; SEP ID CHARGE-EQUILIBRATION; ACCELERATION; SPACECRAFT; PLASMA; IONS; SUN AB We studied the coronal mass ejections (CMEs) and flares associated with large solar energetic particle (SEP) events of solar cycle 23 (1996-2002) in order to determine what property of the solar eruptions might order the SEP intensity. The SEP events were divided into three groups: (1) events in which the primary CME was preceded by one or more wide CMEs from the same solar source, (2) events with no such preceding CMEs, and (3) events in which the primary CME might have interacted with a streamer or with a nearby halo CME. The SEP intensities are distinct for groups 1 and 2 although the CME properties were nearly identical. Group 3 was similar to group 1. The primary findings of this study are as follows: (1) Higher SEP intensity results whenever a CME is preceded by another wide CME from the same source region. (2) The average flare size was also larger for high-intensity SEP events. (3) The intensity of SEP events with preceding CMEs showed a tighter correlation with CME speed. The extent of scatter in the CME speed versus SEP intensity plots was reduced when various subgroups were considered separately. (4) The intensities of energetic electrons were better correlated with flare size than with CME speed. (5) The SEP intensity showed poor correlation with the flare size, except for group 3 events. Since only a third of the events did not have preceding CMEs, we conclude that the majority of SEP producing CMEs propagate through the near-Sun interplanetary medium severely disturbed and distorted by the preceding CMEs. Furthermore, the preceding CMEs are faster and wider on the average, so they may provide seed particles for CME-driven shocks that follow. Therefore we conclude that the differing intensities of SEP events in the two groups may not have resulted due to the inherent properties of the CMEs. The presence of preceding CMEs seems to be the discriminating characteristic of the high- and low-intensity SEP events. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Catholic Univ Amer, Washington, DC 20064 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. USN, Solar Phys Branch, Div Space Sci, Res Lab, Washington, DC 20375 USA. RP Gopalswamy, N (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM gopals@fugee.gsfc.nasa.gov; yashiro@cdaw.gsfc.nasa.gov; krucker@ssl.berkeley.edu; stenborg@kreutz.nascom.nasa.gov; russ.howard@nrl.navy.mil RI Gopalswamy, Nat/D-3659-2012 NR 33 TC 150 Z9 152 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 DEC 15 PY 2004 VL 109 IS A12 AR A12105 DI 10.1029/2004JA010602 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 881QS UT WOS:000225883700002 ER PT J AU Hund, JF Bertino, MF Zhang, G Sotiriou-Leventis, C Leventis, N AF Hund, JF Bertino, MF Zhang, G Sotiriou-Leventis, C Leventis, N TI Synthesis of homogeneous alloy metal nanoparticles in silica aerogels SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 7th International Symposium on Aerogels CY NOV 02-05, 2003 CL Alexandria, VA ID COMPOSITE AEROGELS; GOLD; SILVER; CATALYSTS; MONOLITHS; CLUSTERS; SOL; AG AB Homogeneous alloy nanoparticles of the noble metals gold and silver were formed in silica aerogels. In our synthesis procedure, silica aquogels were first prepared with a standard base-catalyzed route, washed several times with distilled water, and then bathed in an aqueous solution with a total metal ion concentration of 3 x 10(-4) M. Formaldehyde (0.5 M) was then added as a reducing agent, with NaOH, in a typical concentration of 1-2 mM, employed to control the velocity of reduction. After reduction, the gels were washed, and then dried supercritically (from CO2) to yield aerogels. The optical absorption of the gels exhibits a single plasmon peak that shifts linearly to higher wavelengths when the Au mole ratio is increased. These results indicate that bimetallic nanoparticles are formed, and that the metals are homogeneously alloyed. Transmission electron microscopy shows that the diameter of the metal nanoparticles depends on the molar ratio of metals used in the bathing solution of the aquogel precursor, and ranges from a minimum of similar to20 nm (100% Au sample) to a maximum of 70-80 nm (25 at.% Au). Energy-dispersive X-ray analysis confirms that the nanoparticles are bimetallic, with a mean mole ratio within 15% of the bathing solution. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Missouri, Dept Phys, Rolla, MO 65409 USA. Univ Missouri, Dept Chem, Rolla, MO 65409 USA. NASA, Glenn Res Ctr, Div Mat, Polymers Branch, Cleveland, OH 44135 USA. RP Bertino, MF (reprint author), Univ Missouri, Dept Phys, 1870 Miner Circle, Rolla, MO 65409 USA. EM massimo@umr.edu NR 22 TC 6 Z9 6 U1 1 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD DEC 15 PY 2004 VL 350 BP 9 EP 13 DI 10.1016/j.jnoncrysol.2004.06.037 PG 5 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 884MK UT WOS:000226089200003 ER PT J AU Tang, PE Sakamoto, JS Baudrin, E Dunn, B AF Tang, PE Sakamoto, JS Baudrin, E Dunn, B TI V2O5 aerogel as a versatile host for metal ions SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 7th International Symposium on Aerogels CY NOV 02-05, 2003 CL Alexandria, VA ID RECHARGEABLE LITHIUM BATTERIES; VANADIUM-OXIDE AEROGELS; ELECTROCHEMICAL PROPERTIES; INTERCALATION; CATHODE AB Vanadium pentoxide aerogels have the ability to electrochemically insert a wide variety of metal ions. This paper describes the reversible insertion of Na+, K+, Mg2+, and Ba2+: these ions represent a progression of ion size and charge. A critical factor in their insertion is the role of surface morphology, as it appears that divalent insertion, in particular, is associated with the high surface area of the aerogel. In nearly all cases, the amount of reversible insertion greatly exceeds values reported for other materials. Moreover, this is the first report of reversible electrochemical insertion of Ba2+ in solids. The measurements indicate a general trend of lower specific energy density as charge increases. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Mat & Devices Technol Grp, Pasadena, CA 91109 USA. Univ Picardie, Lab Reactiv & Chim Solides, CNRS, UMR 6007, F-80039 Amiens, France. RP Dunn, B (reprint author), Univ Calif Los Angeles, Dept Mat Sci & Engn, Los Angeles, CA 90095 USA. EM bdunn@ucla.edu OI Baudrin, Emmanuel/0000-0001-9551-6859 NR 24 TC 48 Z9 50 U1 4 U2 40 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD DEC 15 PY 2004 VL 350 BP 67 EP 72 DI 10.1016/j.jnoncrysol.2004.07.072 PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 884MK UT WOS:000226089200011 ER PT J AU Zhang, GH Dass, A Rawashdeh, AMM Thomas, J Counsil, JA Sotiriou-Leventis, C Fabrizio, EF Ilhan, F Vassilaras, P Scheiman, DA McCorkle, L Palczer, A Johnston, JC Meador, MA Leventis, N AF Zhang, GH Dass, A Rawashdeh, AMM Thomas, J Counsil, JA Sotiriou-Leventis, C Fabrizio, EF Ilhan, F Vassilaras, P Scheiman, DA McCorkle, L Palczer, A Johnston, JC Meador, MA Leventis, N TI Isocyanate-crosslinked silica aerogel monoliths: preparation and characterization SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 7th International Symposium on Aerogels CY NOV 02-05, 2003 CL Alexandria, VA ID SOL AB Polymerization of di- and tri-isocyanates can be templated onto the mesoporous surface of a preformed network of sol-gel-derived silica nanoparticles, resulting in a conformal 'crosslinked' coating that renders the interparticle neck zone wider. Upon drying, these crosslinked networks yield aerogels which are up to similar to3x more dense than native aerogels based on the underlying silica framework, but also up to 10x less hygroscopic and they may take more than 300x the force to break. These results have been obtained with one-step based-catalyzed sol-gel silica networks, as well as with gels derived through a two-step process involving an acid-catalyzed sol and a based-catalyzed gel. Furthermore, it has been also found that crosslinking increases the dielectric constant only by similar to35% relative to values reported in the literature for native silica aerogels of about the same porosity. Chemical investigations into the polymerization reaction have shown that the process of crosslinking involves reaction of the isocyanate with: (a) -OH groups at the surface of silica to form carbamate; and (b) adsorbed water, to form an amine and carbon dioxide. This amine then reacts with additional isocyanates resulting in polymer chain extension and bridging of particles with urethane-terminated polyurea. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Missouri, Dept Chem, Rolla, MO 65409 USA. NASA, Glenn Res Ctr, Div Mat, Cleveland, OH 44135 USA. RP Sotiriou-Leventis, C (reprint author), Univ Missouri, Dept Chem, Rolla, MO 65409 USA. EM cslevent@umr.edu; nicholas.leventis@nasa.gov RI Dass, Amal/A-2520-2011; Dass, Amala/H-4729-2012; OI Dass, Amala/0000-0001-6942-5451; Meador, Mary Ann/0000-0003-2513-7372 NR 28 TC 91 Z9 99 U1 6 U2 59 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD DEC 15 PY 2004 VL 350 BP 152 EP 164 DI 10.1016/j.jnoncrysol.2004.06.041 PG 13 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 884MK UT WOS:000226089200023 ER PT J AU Mincov, I Petkov, MP Tsou, P Troev, T AF Mincov, I Petkov, MP Tsou, P Troev, T TI Porosity characterization of aerogels using positron annihilation lifetime spectroscopy SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 7th International Symposium on Aerogels CY NOV 02-05, 2003 CL Alexandria, VA ID THIN-FILMS; PORE-SIZE; SURFACES; POLYMERS; CONTIN; GLASS AB We utilized positron annihilation lifetime spectroscopy (PALS) for non-destructive characterization of porosity in aerogels, using positronium (Ps; an electron-positron bound state) as a probe. PALS measures Ps lifetime in pores and uses models to translate that into a spatial measure (mean free path), which can then be converted to pore size for known shape. For these feasibility studies, aerogel samples with different densities were compared and distinguished on the basis of the PALS results alone. Discrete component comparative analysis was carried out for all samples and a continuous distribution was derived for one sample. All samples exhibited Ps signals ascribed to a bimodal porosity structure comprising a dominant (80-85%) component, spanning nearly the entire meso- and macro-pore size ranges, and a smaller (10-15%) microporous contribution with a spherical equivalent diameter of similar to2 nm. To describe the irregularly shaped pores in aerogels, the diameter of a sphere and the cross-section of a long narrow channel were considered, respectively, as the upper and lower bound of the actual pore sizes. The maximum of the mesoporous distribution was thus between 8nm (channels) and 12nm (spheres), with the lower bound arguably being more representative of the aerogels porosity. A comparison between the results of PALS and these of other commonly used techniques is discussed. (C) 2004 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Bulgarian Acad Sci, Inst Nucl Res & Nucl Energy, BG-1784 Sofia, Bulgaria. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM mihail.p.petkov@jpl.nasa.gov RI Mincov, Ivaylo/B-9485-2009 OI Mincov, Ivaylo/0000-0001-5602-9820 NR 26 TC 9 Z9 9 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 EI 1873-4812 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD DEC 15 PY 2004 VL 350 BP 253 EP 258 DI 10.1016/j.jnoncrysol.2004.06.024 PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 884MK UT WOS:000226089200036 ER PT J AU Dominguez, G Phillips, MLF Jones, SM Westphal, AJ AF Dominguez, G Phillips, MLF Jones, SM Westphal, AJ TI Fluorescent impact cavities in a titanium-doped Al2O3-SiO2 aerogel: implications for the velocity resolution of calorimetric aerogels SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article; Proceedings Paper CT 7th International Symposium on Aerogels CY NOV 02-05, 2003 CL Alexandria, VA ID LOW-EARTH-ORBIT; HYPERVELOCITY IMPACTS; DUST; PARTICLES; CAPTURE; STARDUST AB Silica aerogels have been shown to be superior at capturing hypervelocity projectiles with minimal alteration. On the basis of what is known about the abundance of natural projectiles in low Earth orbit (LEO), aerogel collectors flown in LEO should collect numerous scientifically interesting extraterrestrial dust particles, including interstellar dust grains. However, to date, only a few extraterrestrial dust grains have been found and not a single contemporary interstellar dust grain has ever been identified or analyzed in the laboratory. This lack of success is due to the fact that when using conventional aerogels it is very difficult, if not impossible, to reconstruct the velocity of captured natural projectiles. To address this problem, we are currently developing aerogel collectors/detectors that passively record the kinetic energy of an impacting projectile. In our previous work, we demonstrated that (Gd, Tb)-doped alumina aerogels may transform into a fluorescent phase(s) as a result of the rapid shock heating experienced by the capture of hypervelocity projectiles and that the amount of fluorescence excited, using a UV light source, is an increasing function of the projectile's kinetic energy. However, our previous work did not demonstrate the accuracy of this `calorimetric' technique in reconstructing the impact velocity of projectiles. In this paper, we report on the production of fluorescent impact cavities in a Ti-doped (5%) SiO2-Al2O3 aerogel monolith that resulted from the capture of 4.37 kms(-1) 20mum glass beads. In addition we demonstrate that the dispersion of the fluorescent response of this aerogel implies that we should be able to reconstruct the velocity of a captured projectile with a resolution of 20% or better. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Calif Berkeley, Space Sci Lab, Dept Phys, Berkeley, CA 94720 USA. Pleasanton Ridge Res Corp, Hayward, CA 91109 USA. CALTECH, Jet Prop Lab, Hayward, CA 94542 USA. RP Dominguez, G (reprint author), Univ Calif Berkeley, Space Sci Lab, Dept Phys, 7 Gauss Way, Berkeley, CA 94720 USA. EM domi@socrates.berkeley.edu NR 15 TC 4 Z9 4 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD DEC 15 PY 2004 VL 350 BP 385 EP 390 DI 10.1016/j.jnoncrysol.2004.06.027 PG 6 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 884MK UT WOS:000226089200055 ER PT J AU Rodriguez, LA Watson, IM Rose, WI Branan, YK Bluth, GJS Chigna, G Matias, O Escobar, D Carn, SA Fischer, TP AF Rodriguez, LA Watson, IM Rose, WI Branan, YK Bluth, GJS Chigna, G Matias, O Escobar, D Carn, SA Fischer, TP TI SO2 emissions to the atmosphere from active volcanoes in Guatemala and El Salvador, 1999-2002 SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE sulfur dioxide; COSPEC; gas monitoring; Guatemala; El Salvador; degassing ID SOUFRIERE HILLS VOLCANO; TROPOSPHERIC SULFATE; AIR-POLLUTANTS; SULFUR; MODEL; DOME; MONTSERRAT; EVOLUTION; ERUPTIONS; COLOMBIA AB Ground-based and aircraft correlation spectrometer (COSPEC) measurements at the principal active volcanoes in Guatemala (Pacaya, Santiaguito, Fuego, and Tacana) and El Salvador (Santa Ana and San Miguel) were carried out at intervals during the period 1999-2002, as part of an attempt to measure baseline SO2 emissions of potentially dangerous volcanoes and to better understand their eruption mechanisms. We discuss some of the uncertainties involved in interpreting intermittent gas data, together with possible improvements. Other problems pertaining to current monitoring of SO2 and implications for future studies are also discussed. Santa Ana volcano is proposed to be a venting hydrothermal system, while Santiaguito, Fuego, Pacaya, and San Miguel all exhibit open-vent characteristics. Data for Tacana volcano are presented, but are not enough to make descriptions of its characteristics and activity. Pacaya is emitting high fluxes of SO2 ( greater than or equal to 1000 tonnes/day), while the other vents are much lower emitters (20-300 tonnes/day in general). SO2 emissions at Pacaya suggest a large circulating and convecting high level chamber. The most recent emission rates at Fuego were measured during its current active phase (since January 2002). Average SO2 emission rates during 1999-2002 are: 1350 tonnes/day for Pacaya, 340 tonnes/day for Fuego, 120 tonnes/day for Santiaguito, 260 tonnes/day for San Miguel, 140 tonnes/day for Santa Ana, and 30 tonnes/day for Tacana. These volcanoes account for about 6% to 12% of the estimated annual global volcanic output of SO2. (C) 2004 Elsevier B.V. All rights reserved. C1 Michigan Technol Univ, Houghton, MI 49931 USA. INSIVUMEH, Guatemala City, Guatemala. Serv Nacl Estudios Territoriales, San Salvador, El Salvador. Univ Maryland, NASA, UMBC, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. RP Rodriguez, LA (reprint author), Michigan Technol Univ, 1400 Townsend Dr, Houghton, MI 49931 USA. EM larodrig@mtu.edu RI Rose, William/A-7923-2009; Watson, Matt/E-5236-2011 OI Watson, Matt/0000-0001-9198-2203 NR 60 TC 29 Z9 31 U1 0 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD DEC 15 PY 2004 VL 138 IS 3-4 BP 325 EP 344 DI 10.1016/j.jvolgeores.2004.07.008 PG 20 WC Geosciences, Multidisciplinary SC Geology GA 874JA UT WOS:000225345500008 ER PT J AU Thorpe, JI Cruz, RL Sankar, SR Mueller, G McNamara, P AF Thorpe, JI Cruz, RL Sankar, SR Mueller, G McNamara, P TI First step toward a benchtop model of the Laser Interferometer Space Antenna SO OPTICS LETTERS LA English DT Article ID FREQUENCY STABILIZATION; PHASE AB A technique for simulating large optical path lengths by use of digital delay buffers is presented. This technique is used to generate a synthetic interferometer with one arm having an arbitrary length. The response of the interferometer to phase and frequency modulation is measured and found to be in agreement with predictions. This technique could be used to simulate long-baseline interferometric space missions such as the Laser Interferometer Space Antenna. (C) 2004 Optical Society of America. C1 Univ Florida, Dept Phys, Gainesville, FL 32611 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Thorpe, JI (reprint author), Univ Florida, Dept Phys, POB 118440, Gainesville, FL 32611 USA. EM ithorpe@phys.ufl.edu RI Thorpe, James/D-3150-2012 NR 7 TC 6 Z9 6 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 DEC 15 PY 2004 VL 29 IS 24 BP 2843 EP 2845 DI 10.1364/OL.29.002843 PG 3 WC Optics SC Optics GA 878YG UT WOS:000225682900003 PM 15645799 ER PT J AU Gregg, WW Casey, NW AF Gregg, WW Casey, NW TI Global and regional evaluation of the SeaWiFS chlorophyll data set SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE SeaWiFS; chlorophyll; global and regional evaluation ID OCEAN COLOR DATA; REMOTE-SENSING REFLECTANCE; ANTARCTIC PENINSULA WATERS; DISSOLVED ORGANIC-MATTER; TROPICAL PACIFIC-OCEAN; MARINE ECOSYSTEM MODEL; HARMFUL ALGAL BLOOMS; SOUTHERN-OCEAN; COASTAL WATERS; ATMOSPHERIC CORRECTION AB The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) chlorophyll data set was compared to comprehensive archives of in situ chlorophyll data from NASA and NOAA. The global comparison indicated a root mean square (RMS) log error of 31%, with a coefficient of determination (r(2)) of 0.76, using 4168 data points where in situ and SeaWiFS data were coincident and collocated. RMS log error for open ocean (defined as bottom depth>200 in) was 27.7% with r(2) = 0.72, compared to 33% RMS log error and r(2) = 0.60 on the coasts, indicating a deterioration of quality of the SeaWiFS data set in coastal regions. All of the Pacific oceanographic basins generally showed very good agreement with SeaWiFS, as did the South Atlantic basin. However, poorer agreement was found in the Mediterranean/Black Seas, Equatorial Atlantic, and the Antarctic. Optical complexity arising from riverine inputs, Saharan dust, and anomalous oceanic constituents contributed to the differences observed in the Atlantic, where an overestimation by SeaWiFS occurred. The Antarctic indicated a pronounced negative bias, indicating an underestimation, especially for chlorophyll concentrations greater than about 0.15 mg m(-3). The results provide a comprehensive global and geographic analysis of the SeaWiFS data set, which will assist data users and policy makers in assessing the uncertainty of estimates of global and regional ocean chlorophyll and primary production. (C) 2004 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Seabrook, MD 20706 USA. RP NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Lab Hydrospher Proc, Code 971, Greenbelt, MD 20771 USA. EM Watson.W.Gregg@nasa.gov NR 77 TC 166 Z9 167 U1 3 U2 28 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 DEC 15 PY 2004 VL 93 IS 4 BP 463 EP 479 DI 10.1016/j.rse.2003.12.012 PG 17 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 874PA UT WOS:000225361100002 ER PT J AU Lanari, R Lundgren, P Manzo, M Casu, F AF Lanari, R Lundgren, P Manzo, M Casu, F TI Satellite radar interferometry time series analysis of surface deformation for Los Angeles, California SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SYNTHETIC-APERTURE RADAR; PERMANENT SCATTERERS; LAND SUBSIDENCE; GROUNDWATER; VALLEY AB The Los Angeles, California, metropolitan area is a tectonically active region with surface deformation that is a combination of fault related tectonics plus a variety of natural and anthropogenic signals. We apply the small baseline subset (SBAS) algorithm to produce an interferometric synthetic aperture radar (InSAR) time series analysis for the Los Angeles area using data acquired by the ERS satellites from late 1995 into 2002. The result is a space-time deformation product that can be exploited to view not only the smoothly varying long-term surface motion, but also its time varying patterns. Large seasonal oscillations of the Santa Ana aquifer observed in Southern California Integrated GPS Network (SCIGN) data are accurately matched in the InSAR time series, moreover, correlations of the InSAR time series with an annual sinusoid allows us to investigate the dynamics of the hydrologic system. C1 CNR, Ist Rilevamento Elettromagnet Ambiente, I-80124 Naples, Italy. CALTECH, Jet Propuls Lab, Pasadena, CA USA. RP Lanari, R (reprint author), CNR, Ist Rilevamento Elettromagnet Ambiente, Via Diocleziano 328, I-80124 Naples, Italy. EM lanari.r@irea.cnr.it RI Casu, Francesco/H-3793-2011; OI MANZO, MARIAROSARIA/0000-0002-9387-5273; Casu, Francesco/0000-0001-8555-6494 NR 11 TC 89 Z9 89 U1 3 U2 30 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 DEC 14 PY 2004 VL 31 IS 23 AR L23613 DI 10.1029/2004GL021294 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 881QC UT WOS:000225881800004 ER PT J AU Allen, DM Navarrete, L Dou, J Schad, R Padmini, P Kale, P Pandey, RK Shojah-Ardalan, S Wilkins, R AF Allen, DM Navarrete, L Dou, J Schad, R Padmini, P Kale, P Pandey, RK Shojah-Ardalan, S Wilkins, R TI Chemical ordering in ilmenite-hematite bulk ceramics through proton irradiation SO APPLIED PHYSICS LETTERS LA English DT Article ID SOLID SOLUTION SERIES; MAGNETIC-PROPERTIES; DISPLACEMENT DAMAGE; PHASE-TRANSITION; ION-IRRADIATION; SILICON; R(3)OVER-BAR AB We demonstrated the capability of MeV proton irradiation to promote chemical ordering processes in a solid at low temperature. We used the ilmenite-hematite solid solution system which allows estimation of the degree of ordering through measurement of its magnetization. Normally, ordering through diffusion would require high temperature annealing. At high temperatures, however, the equilibrium state would be less ordered and thus the achievable ordering incomplete. High energetic protons continuously transfer energy to the sample through electronic interaction which locally deposits large quantities of energy without a general increase of the sample temperature. This promotes diffusion processes which allow the system to relax towards the ordered equilibrium state. (C) 2004 American Institute of Physics. C1 Univ Alabama, Dept Phys, Tuscaloosa, AL 35487 USA. Univ Alabama, Ctr Mat Informat Technol, Tuscaloosa, AL 35487 USA. Univ Alabama, Dept Elect & Comp Engn, Tuscaloosa, AL 35487 USA. Prairie View A&M Univ, Dept Elect Engn, Prairie View, TX 77446 USA. NASA, Ctr Appl Radiat Res, Prairie View, TX 77446 USA. RP Allen, DM (reprint author), Univ Alabama, Dept Phys, Box 870209, Tuscaloosa, AL 35487 USA. NR 23 TC 12 Z9 12 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 13 PY 2004 VL 85 IS 24 BP 5902 EP 5904 DI 10.1063/1.1834989 PG 3 WC Physics, Applied SC Physics GA 878AZ UT WOS:000225620200029 ER PT J AU Mingo, N AF Mingo, N TI Thermoelectric figure of merit of II-VI semiconductor nanowires SO APPLIED PHYSICS LETTERS LA English DT Article ID ELECTRON-TRANSPORT AB The room temperature thermoelectric figure of merit and power factor are calculated for bulk and nanowires made of CdTe, ZnTe, ZnSe, and ZnS, of the zincblende structure. To this end, an iterative solution of the Boltzmann transport equation is used to obtain the electronic transport properties. The lattice thermal conductivity is estimated using a full dispersion transmission function approach. A saturation to finite values is predicted for the power factor in the small thickness limit. The figure of merit increase upon thickness reduction is largest for CdTe, followed by ZnTe, ZnSe, and ZnS. II-VI nanowires show smaller increases of the figure of merit as compared with III-V nanowires, despite their bulk values are of comparable magnitude in the two groups. The reasons for this are explained. (C) 2004 American Institute of Physics. C1 NASA, Ames Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Mingo, N (reprint author), NASA, Ames Ctr Nanotechnol, 229-1, Moffett Field, CA 94035 USA. NR 14 TC 39 Z9 39 U1 1 U2 29 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 DEC 13 PY 2004 VL 85 IS 24 BP 5986 EP 5988 DI 10.1063/1.1829391 PG 3 WC Physics, Applied SC Physics GA 878AZ UT WOS:000225620200057 ER PT J AU Borca-Tasciuc, DA Chen, G Prieto, A Martin-Gonzalez, MS Stacy, A Sands, T Ryan, MA Fleurial, JP AF Borca-Tasciuc, DA Chen, G Prieto, A Martin-Gonzalez, MS Stacy, A Sands, T Ryan, MA Fleurial, JP TI Thermal properties of electrodeposited bismuth telluride nanowires embedded in amorphous alumina SO APPLIED PHYSICS LETTERS LA English DT Article ID ARRAYS; CONDUCTIVITY AB Bismuth telluride nanowires are of interest for thermoelectric applications because of the predicted enhancement in the thermoelectric figure-of-merit in nanowire structures. In this letter, we carried out temperature-dependent thermal diffusivity characterization of a 40 nm diameter Bi2Te3 nanowires/alumina nanocomposite. Measured thermal diffusivity of the composite decreases from 9.2x10(-7) m(2) s(-1) at 150 K to 6.9x10(-7) m(2) s(-1) at 300 K and is lower than thermal diffusivity of unfilled alumina templates. Effective medium calculations indicate that the thermal conductivity along nanowires axis is at least an order of magnitude lower than thermal conductivity of the bulk bismuth telluride. (C) 2004 American Institute of Physics. C1 MIT, Dept Mech Engn, Cambridge, MA 02139 USA. Univ Calif Los Angeles, Dept Mech & Aerosp Engn, Los Angeles, CA 90095 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Purdue Univ, Sch Mat Engn, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chen, G (reprint author), MIT, Dept Mech Engn, Cambridge, MA 02139 USA. EM gchen2@mit.edu RI Sands, Timothy/D-2133-2009; Chen, Gang/J-1325-2014; Martin-Gonzalez, Marisol/E-7076-2010 OI Sands, Timothy/0000-0001-9718-6515; Chen, Gang/0000-0002-3968-8530; Martin-Gonzalez, Marisol/0000-0002-5687-3674 NR 22 TC 53 Z9 53 U1 2 U2 26 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 DEC 13 PY 2004 VL 85 IS 24 BP 6001 EP 6003 DI 10.1063/1.1834991 PG 3 WC Physics, Applied SC Physics GA 878AZ UT WOS:000225620200062 ER PT J AU Bertino, MF Gadipalli, RR Story, JG Williams, CG Zhang, G Sotiriou-Leventis, C Tokuhiro, AT Guha, S Leventis, N AF Bertino, MF Gadipalli, RR Story, JG Williams, CG Zhang, G Sotiriou-Leventis, C Tokuhiro, AT Guha, S Leventis, N TI Laser writing of semiconductor nanoparticles and quantum dots SO APPLIED PHYSICS LETTERS LA English DT Article ID MESOPOROUS SILICA; CDS NANOPARTICLES; THIN-FILMS; SOL; GEL; GROWTH; AEROGELS; FABRICATION; DEPOSITION AB Silica aerogels were patterned with CdS using a photolithographic technique based on local heating with infrared (IR) light. The solvent of silica hydrogels was exchanged with an aqueous solution of the precursors CdNO3 and NH4OH, all precooled to a temperature of 5degreesC. Half of the bathing solution was then replaced by a thiourea solution. After thiourea diffused into the hydrogels, the samples were exposed to a focused IR beam from a continuous wave, Nd-YAG laser. The precursors reacted in the spots heated by the IR beam to form CdS nanoparticles. We lithographed features with a diameter of about 40 mum, which extended inside the monoliths for up to 4 mm. Samples were characterized with transmission electron microscopy and optical absorption, photoluminescence, and Raman spectroscopies. Spots illuminated by the IR beam were made up by CdS nanoparticles dispersed in a silica matrix. The CdS nanoparticles had a diameter in the 4-6 nm range in samples exposed for 4 min to the IR beam, and of up to 100 nm in samples exposed for 10 min. (C) 2004 American Institute of Physics. C1 Univ Missouri, Dept Phys, Rolla, MO 65409 USA. Univ Missouri, Dept Chem, Rolla, MO 65409 USA. Univ Missouri, Dept Nucl Engn, Rolla, MO 65409 USA. Univ Missouri, Dept Phys, Columbia, MO 65211 USA. NASA, Glenn Res Ctr, Div Mat, Polymers Branch, Cleveland, OH 44135 USA. RP Bertino, MF (reprint author), Univ Missouri, Dept Phys, Rolla, MO 65409 USA. EM massimo@umr.edu; cslevent@umr.edu; nicholas.leventis@nasa.gov RI Guha, Suchi/B-6477-2013 OI Guha, Suchi/0000-0002-6269-2298 NR 30 TC 22 Z9 22 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD DEC 13 PY 2004 VL 85 IS 24 BP 6007 EP 6009 DI 10.1063/1.1836000 PG 3 WC Physics, Applied SC Physics GA 878AZ UT WOS:000225620200064 ER PT J AU Bloemhof, EE Wallace, JK AF Bloemhof, EE Wallace, JK TI Simple broadband implementation of a phase contrast wavefront sensor for adaptive optics SO OPTICS EXPRESS LA English DT Article AB The most critical element of an adaptive optics system is its wavefront sensor, which must measure the closed-loop difference between the corrected wavefront and an ideal template at high speed, in real time, over a dense sampling of the pupil. Most high-order systems have used Shack-Hartmann wavefront sensors, but a novel approach based on Zernike's phase contrast principle appears promising. In this paper we discuss a simple way to achromatize such a phase contrast wavefront sensor, using the pi/2 phase difference between reflected and transmitted rays in a thin, symmetric beam splitter. We further model the response at a range of wavelengths to show that the required transverse dimension of the focal-plane phase-shifting spot, nominally lambda/D, may not be very sensitive to wavelength, and so in practice additional optics to introduce wavelength-dependent transverse magnification achromatizing this spot diameter may not be required. A very simple broadband implementation of the phase contrast wavefront sensor results. (C) 2004 Optical Society of America. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91101 USA. RP Bloemhof, EE (reprint author), CALTECH, Jet Prop Lab, Pasadena, CA 91101 USA. EM Eric.E.Bloemhof@jpl.nasa.gov NR 15 TC 11 Z9 11 U1 1 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD DEC 13 PY 2004 VL 12 IS 25 BP 6240 EP 6245 DI 10.1364/OPEX.12.006240 PG 6 WC Optics SC Optics GA 879HZ UT WOS:000225708300020 PM 19488269 ER PT J AU Heald, CL Jacob, DJ Jones, DBA Palmer, PI Logan, JA Streets, DG Sachse, GW Gille, JC Hoffman, RN Nehrkorn, T AF Heald, CL Jacob, DJ Jones, DBA Palmer, PI Logan, JA Streets, DG Sachse, GW Gille, JC Hoffman, RN Nehrkorn, T TI Comparative inverse analysis of satellite (MOPITT) and aircraft (TRACE-P) observations to estimate Asian sources of carbon monoxide SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE MOPITT; TRACE-p; carbon monoxide; Asia; Bayesian synthesis; inversion ID GLOBAL 3-DIMENSIONAL MODEL; TRANSPORT PATHWAYS; WESTERN PACIFIC; AIR-POLLUTION; EMISSIONS; CO; ASSIMILATION; TROPOSPHERE; INSTRUMENT; BUDGETS AB We use an inverse model analysis to compare the top-down constraints on Asian sources of carbon monoxide (CO) in spring 2001 from (1) daily MOPITT satellite observations of CO columns over Asia and the neighboring oceans and (2) aircraft observations of CO concentrations in Asian outflow from the TRACE-P aircraft mission over the northwest Pacific. The inversion uses the maximum a posteriori method (MAP) and the GEOS-CHEM chemical transport model (CTM) as the forward model. Detailed error characterization is presented, including spatial correlation of the model transport error. Nighttime MOPITT observations appear to be biased and are excluded from the inverse analysis. We find that MOPITT and TRACE-P observations are independently consistent in the constraints that they provide on Asian CO sources, with the exception of southeast Asia for which the MOPITT observations support a more modest decrease in emissions than suggested by the aircraft observations. Our analysis indicates that the observations do not allow us to differentiate source types (i.e., anthropogenic versus biomass burning) within a region. MOPITT provides ten pieces of information to constrain the geographical distribution of CO sources, while TRACE-P provides only four. The greater information from MOPITT reflects its ability to observe all outflow and source regions. We conducted a number of sensitivity studies for the inverse model analysis using the MOPITT data. Temporal averaging of the MOPITT data (weekly and beyond) degrades the ability to constrain regional sources. Merging source regions beyond what is appropriate after careful selection of the state vector leads to significant aggregation errors. Calculations for an ensemble of realistic assumptions lead to a range of inverse model solutions that has greater uncertainty than the a posteriori errors for the MAP solution. Our best estimate of total Asian CO sources is 361 Tg yr(-1), over half of which is attributed to east Asia. C1 Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. Natl Ctr Atmospher Res, Boulder, CO 80303 USA. AER Inc, Lexington, MA 02173 USA. Univ Toronto, Dept Phys, Toronto, ON M5S 1A7, Canada. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. EM heald@fas.harvard.edu RI Palmer, Paul/F-7008-2010; Heald, Colette/A-6813-2011; Jones, Dylan/O-2475-2014; Chem, GEOS/C-5595-2014; OI Jones, Dylan/0000-0002-1935-3725; Streets, David/0000-0002-0223-1350; Nehrkorn, Thomas/0000-0003-0637-3468 NR 54 TC 122 Z9 122 U1 1 U2 13 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 DEC 11 PY 2004 VL 109 IS D23 AR D23306 DI 10.1029/2004JD005185 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 881PK UT WOS:000225879600005 ER PT J AU Singh, RP Dey, S Tripathi, SN Tare, V Holben, B AF Singh, RP Dey, S Tripathi, SN Tare, V Holben, B TI Variability of aerosol parameters over Kanpur, northern India SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosol; remote sensing; Ganga basin ID SKY RADIANCE MEASUREMENTS; SINGLE-SCATTERING ALBEDO; OPTICAL-PROPERTIES; ATMOSPHERIC AEROSOL; SIZE DISTRIBUTIONS; UNITED-STATES; EAST-COAST; AERONET; DEPTH; RADIATION AB Aerosol optical properties and the spectral behavior of the aerosol optical depth (AOD) over Kanpur, an urban-industrial city in the Ganga basin, have been presented for the first time. Measurements by the ground-based Aerosol Robotic Network (AERONET) during January 2001 to December 2003 show pronounced seasonal influence, with maximum dust loading during the premonsoon season (April-May). The distribution of AOD is found to be large with a mean value of 0.6 at 500 nm wavelength. The frequency distribution of the Angstrom parameter a reveals two modes (alpha < 1 dominant dusty condition and alpha > 1 urban aerosols). Diurnal variations of AOD, water vapor content (WVC), and Angstrom parameter show strong seasonal influence. Maximum variation of AOD is found during the monsoon season (presence of mixed types of aerosols), maximum variation of WVC is observed during the winter season (frequent changes in humidity and air pressure), and a shows maximum variations during the premonsoon (dust dominating the atmospheric optical conditions) season. The aerosol volume size distributions show two distinct modes, fine (geometric mean radii of 0.17 mum and standard deviation of 0.03) and coarse (geometric mean radii of 3.37 mum and standard deviation of 0.1), but during May-August (period of dust loading), a third mode (around 1-2 mum) appears because of hygroscopic growth of finer aerosols. The single-scattering albedo (SSA) is found to increase with wavelength in the presence of dust and shows a reverse trend in dust-free conditions. Refractive indices show the presence of dust as the main component during the premonsoon season and dominance of anthropogenic urban-industrial aerosols during the winter season, when the optical state of the atmosphere is more absorbing. The aerosol parameters show distinct interannual variations, with increasing aerosol burden over the region. Aerosol loading over Kanpur is found to be controlled by the regional climatology. C1 Indian Inst Technol, Dept Civil Engn, Kanpur 208016, Uttar Pradesh, India. NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. RP George Mason Univ, Sch Computat Sci, Fairfax, VA 22030 USA. EM rsingh3@gmu.edu RI Singh, Ramesh/G-7240-2012; Tripathi, Sachchida/J-4840-2016 NR 52 TC 224 Z9 225 U1 3 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 DEC 11 PY 2004 VL 109 IS D23 AR D23206 DI 10.1029/2004JD004966 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 881PK UT WOS:000225879600003 ER PT J AU Osteria, G Campana, D Barbarino, G Boscherini, M Menn, W Mitchell, J Rossi, G Russo, S Simon, M Streitmatter, R AF Osteria, G Campana, D Barbarino, G Boscherini, M Menn, W Mitchell, J Rossi, G Russo, S Simon, M Streitmatter, R TI The time-of-flight system of the PAMELA experiment on satellite SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 10th International Vienna Conference on Instrumentation CY FEB 16-21, 2004 CL Vienna, AUSTRIA SP Fed Minist Educ, Sci & Culture, Fed Minist Transport, Innovat & Technol, Austrian Acad Sci, Univ Technol, Vienna, Vienna Convent Bur, European Phys Soc DE antimatter research; electronics; trigger; scintillation counters; space borne experiment AB The PAMELA (Adriani et al., Nucl. Instr. and Meth. A 478 (2002) 114) (a Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) satellite-borne experiment, scheduled to be launched at the end of 2004, aboard a Soyuz TM2 rocket, is designed to provide a better understanding of the antimatter component of cosmic rays. Its scintillator telescope system will provide the primary experimental trigger and time-of-flight particle identification. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Naples Federico II, I-80126 Naples, Italy. Ist Nazl Fis Nucl, Sez Napoli, I-80126 Naples, Italy. Univ Siegen, D-57068 Siegen, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Osteria, G (reprint author), Univ Naples Federico II, Complesso Univ Monte S Angele,Via Cintia, I-80126 Naples, Italy. EM osteria@na.infn.it RI Barbarino, Giancarlo/L-2559-2015 OI Barbarino, Giancarlo/0000-0001-9253-3397 NR 6 TC 16 Z9 16 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 11 PY 2004 VL 535 IS 1-2 BP 152 EP 157 DI 10.1016/j.nima.2004.07.120 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 877OS UT WOS:000225580500023 ER PT J AU Nakamura, M Meier, DL AF Nakamura, M Meier, DL TI Poynting flux-dominated jets in decreasing-density atmospheres. I. The nonrelativistic current-driven kink instability and the formation of "wiggled" structures SO ASTROPHYSICAL JOURNAL LA English DT Review DE instabilities; galaxies : active; galaxies : jets; methods : numerical; MHD ID GAMMA-RAY BURST; KELVIN-HELMHOLTZ INSTABILITY; YOUNG STELLAR OBJECTS; DOUBLE RADIO-SOURCES; HERBIG-HARO OBJECTS; GLOBAL ASYMPTOTIC SOLUTIONS; RADIATIVELY COOLING JETS; MAGNETIZED ROTATING JETS; ACTIVE GALACTIC NUCLEI; TRANS-ALFVENIC JETS AB Nonrelativistic three-dimensional magnetohydrodynamic (MHD) simulations of Poynting flux-dominated (PFD) jets are presented. Our study focuses on the propagation of strongly magnetized hypersonic but sub-Alfvenic (C(s)(2)much less thanV(j)(2)1). In the jet frame the mode grows locally and expands radially at each axial position where the jet is unstable: the instability, therefore, does not propagate as a wave along the jet length. CD instabilities have a number of features that make them an attractive explanation for the helical jet structure observed in active galactic nuclei and pulsars: (1) because the magnetic field remains strong, CD instabilities do not develop into full MHD turbulence; (2) the helical structures saturate and advect with the bulk flow; (3) they distort the body of the jet, not merely its interface with the ambient medium; (4) local plasma flow, then, follows a helical path along the kinked magnetic field backbone. A naturally occurring, external helically magnetized wind, which is (quasi-)axially current-free, surrounds the well-collimated current-carrying jet and reduces velocity shear between the jet and external medium. This stabilizes the growth of MHD Kelvin-Helmholtz surface modes in the inner jet flow. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM masanori.nakamura@jpl.nasa.gov NR 156 TC 62 Z9 62 U1 0 U2 5 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 DEC 10 PY 2004 VL 617 IS 1 BP 123 EP 154 DI 10.1086/425337 PN 1 PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 880CP UT WOS:000225766700008 ER PT J AU Evans, IN Koratkar, AP AF Evans, IN Koratkar, AP TI Chandra X-ray observations of the inner optical filaments in Centaurus A SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (NGC 5128); galaxies : ISM; X-rays : galaxies ID RADIO-LOBE; NGC 5128; NGC-5128; REGION; JETS AB We have obtained Chandra High Resolution Camera (0.1-10 keV) X-ray imaging of the inner optical filaments of Cen A. Faint X-ray emission is observed associated with the filaments with significance levels of 2-3.5 sigma when the data are adaptively smoothed. Comparison with optical [O III] lambda5007 emission-line imaging suggests that the X-ray-emitting gas is associated with the northwest edge of the optical line-emitting gas. This region of the filaments is closest to the radio jet and is therefore a candidate for shock heating induced by turbulent instabilities in the interstellar medium. The observed X-ray luminosity is significantly smaller than that predicted by purely radiative shock models of the filaments, implying that mechanical energy input does not provide 100% of the ionizing energy budget for the filaments. C1 Smithsonian Astrophys Observ, Cambridge, MA 02138 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. RP Evans, IN (reprint author), Smithsonian Astrophys Observ, 60 Garden St,MS-81, Cambridge, MA 02138 USA. EM ievans@cfa.harvard.edu; koratkar@umbc.edu NR 27 TC 6 Z9 6 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 DEC 10 PY 2004 VL 617 IS 1 BP 209 EP 213 DI 10.1086/425164 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 880CP UT WOS:000225766700014 ER PT J AU McKernan, B Yaqoob, T Reynolds, CS AF McKernan, B Yaqoob, T Reynolds, CS TI OVII and OVIII absorption by hot gas in the vicinity of the Galaxy SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : ISM; galaxies : Seyfert; techniques : spectroscopic; X-rays : ISM ID X-RAY FOREST; ACTIVE GALACTIC NUCLEI; HIGH-VELOCITY CLOUDS; INTERGALACTIC MEDIUM; CHANDRA DETECTION; ALPHA ABSORPTION; LOW-REDSHIFT; LOCAL GROUP; LINE; SPECTROSCOPY AB We searched for evidence of soft X-ray absorption by hot gas in the vicinity of the Galaxy in a small sample of 15 type I active galactic nuclei (AGNs) observed with the high resolution X-ray gratings on board Chandra. We find that around half of the sight lines in our sample exhibit absorption due to local H- or He-like oxygen (or both) at confidence levels ranging from >90% to >3 sigma. Depending on the sight line, the absorption can be identified with hot gas in particular local structures, the Local Group (LG), or the putative local hot intergalactic medium (IGM). Several sight lines in our sample coincide with sight lines in a study of O VI absorption by local gas, so an assumption of collisional ionization equilibrium (CIE) allows us to constrain the temperature of the local hot gas. In the southern Galactic hemisphere, we identify absorption along the sight line to Fairall 9 with the Magellanic Stream, and this gas has 10(5.75)100 hPa) but cold (less then -20degreesC). Snow based hydrological cycles Such as found in the dry valleys of Antarctica can then explain both the fluvial features and the cold and climate. Life could flourish under such conditions. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP McKay, CP (reprint author), NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. NR 18 TC 2 Z9 2 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 1155-4339 J9 J PHYS IV JI J. Phys. IV PD DEC PY 2004 VL 121 BP 283 EP 288 DI 10.1051/jp4:2004121020 PG 6 WC Physics, Multidisciplinary SC Physics GA 892HD UT WOS:000226640000021 ER PT J AU Arkoosh, MR Clemons, E Kagley, AN Stafford, C Glass, AC Jacobson, K Reno, P Myers, MS Casillas, E Loge, E Johnson, LL Collier, TK AF Arkoosh, MR Clemons, E Kagley, AN Stafford, C Glass, AC Jacobson, K Reno, P Myers, MS Casillas, E Loge, E Johnson, LL Collier, TK TI Survey of pathogens in juvenile salmon Oncorhynchus spp. migrating through Pacific Northwest estuaries SO JOURNAL OF AQUATIC ANIMAL HEALTH LA English DT Article ID BACTERIAL KIDNEY-DISEASE; VIRAL ERYTHROCYTIC NECROSIS; RENIBACTERIUM-SALMONINARUM; CHINOOK SALMON; BRITISH-COLUMBIA; COHO SALMON; INCREASED SUSCEPTIBILITY; NANOPHYETUS-SALMINCOLA; VIBRIO-ANGUILLARUM; CAUSATIVE AGENT AB Although the adverse impact of pathogens on salmon populations in the Pacific Northwest is often discussed and recognized, little is currently known regarding the incidence and corresponding significance of delayed disease-induced mortalities. In the study reported herein, we surveyed the presence and prevalence of selected micro- and macroparasites in out-migrant juvenile coho salmon Oncorhynchus kisutch and Chinook salmon O. tshawytscha from 12 coastal estuaries in the Pacific Northwest over a 6-year period (1996-2001). The major finding of this study was the widespread occurrence of pathogens in wild salmon from Pacific Northwest estuaries. The six most prevalent pathogens infecting both juvenile Chinook and coho salmon were Renibacterium salmoninarum, Nanophyetus salmincola, an erythrocytic cytoplasmic virus (erythrocytic inclusion body syndrome or erythrocytic necrosis virus), and three gram-negative bacteria (Listonella anguillarum, Yersinia ruckeri, and Aeromonas salmonicida). The most prevalent pathogen in both Chinook and coho salmon was N. salmincola, followed by the pathogens R. salmoninarum and the erythrocytic cytoplasmic virus. Statistically significant differences in the prevalence of R. salmoninarum and N. salmincola were observed between Chinook and coho salmon. Based on the prevalence of pathogens observed in this study, disease appears to be a potentially significant factor governing the population numbers of salmon in the Pacific Northwest. Development of a detailed understanding of the principal components influencing the ecology of infectious disease will aid in the development of management and control strategies to mitigate disease in and hence further the recovery of salmon stocks listed under the Endangered Species Act. C1 NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Environm Conservat Div, Newport, OR 97365 USA. NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Fish Ecol Div, Newport, OR 97365 USA. Oregon State Univ, Hatfield Marine Sci Ctr, Dept Microbiol, Newport, OR 97365 USA. NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Environm Conservat Div, Seattle, WA 98112 USA. NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Fish Ecol Div, Newport, OR 97365 USA. RP Arkoosh, MR (reprint author), NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Environm Conservat Div, 2032 SE OSU Dr, Newport, OR 97365 USA. EM mary_arkoosh@noaa.gov NR 51 TC 34 Z9 33 U1 0 U2 16 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0899-7659 J9 J AQUAT ANIM HEALTH JI J. Aquat. Anim. Health PD DEC PY 2004 VL 16 IS 4 BP 186 EP 196 DI 10.1577/H03-071.1 PG 11 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA 886ZF UT WOS:000226271100003 ER PT J AU Ferrare, RA Browell, EV Ismail, S Kooi, SA Brasseur, LH Brackett, VG Clayton, MB Barrick, JDW Diskin, GS Goldsmith, JEM Lesht, BM Podolske, JR Sachse, GW Schmidlin, FJ Turner, DD Whiteman, DN Tobin, D Miloshevich, LM Revercomb, HE Demoz, BB DI Girolamo, P AF Ferrare, RA Browell, EV Ismail, S Kooi, SA Brasseur, LH Brackett, VG Clayton, MB Barrick, JDW Diskin, GS Goldsmith, JEM Lesht, BM Podolske, JR Sachse, GW Schmidlin, FJ Turner, DD Whiteman, DN Tobin, D Miloshevich, LM Revercomb, HE Demoz, BB DI Girolamo, P TI Characterization of upper-troposphere water vapor measurements during AFWEX using LASE SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID INTENSIVE OBSERVATION PERIODS; AEROSOL OPTICAL-PROPERTIES; CHILLED-MIRROR HYGROMETER; RAMAN LIDAR TECHNIQUE; EXPLICIT MICROPHYSICS; HUMIDITY MEASUREMENTS; RADIOSONDE; RADIATION; REGION; PERFORMANCE AB Water vapor mass mixing ratio profiles from NASA's Lidar Atmospheric Sensing Experiment (LASE) system acquired during the Atmospheric Radiation Measurement (ARM)-First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment (FIRE) Water Vapor Experiment (AFWEX) are used as a reference to characterize upper-troposphere water vapor (UTWV) measured by ground-based Raman lidars, radiosondes, and in situ aircraft sensors over the Department of Energy (DOE) ARM Southern Great Plains (SGP) site in northern Oklahoma. LASE was deployed from the NASA DC-8 aircraft and measured water vapor over the ARM SGP Central Facility (CF) site during seven flights between 27 November and 10 December 2000. Initially, the DOE ARM SGP Cloud and Radiation Testbed (CART) Raman lidar (CARL) UTWV profiles were about 5%-7% wetter than LASE in the upper troposphere, and the Vaisala RS80-H radiosonde profiles were about 10% drier than LASE between 8 and 12 km. Scaling the Vaisala water vapor profiles to match the precipitable water vapor (PWV) measured by the ARM SGP microwave radiometer (MWR) did not change these results significantly. By accounting for an overlap correction of the CARL water vapor profiles and by employing schemes designed to correct the Vaisala RS80-H calibration method and account for the time response of the Vaisala RS80-H water vapor sensor, the average differences between the CARL and Vaisala radiosonde upper-troposphere water vapor profiles are reduced to about 5%, which is within the ARM goal of mean differences of less than 10%. The LASE and DC-8 in situ diode laser hygrometer (DLH) UTWV measurements generally agreed to within about 3%-4%. The DC-8 in situ frost point cryogenic hygrometer and Snow White chilled-mirror measurements were drier than the LASE, Raman lidars, and corrected Vaisala RS80H measurements by about 10%-25% and 10%-15%, respectively. Sippican (formerly VIZ Manufacturing) carbon hygristor radiosondes exhibited large variabilities and poor agreement with the other measurements. PWV derived from the LASE profiles agreed to within about 3% on average with PWV derived from the ARM SGP microwave radiometer. The agreement between the LASE and MWR PWV and the LASE and CARL UTWV measurements supports the hypotheses that MWR measurements of the 22-GHz water vapor line can accurately constrain the total water vapor amount and that the CART Raman lidar, when calibrated using the MWR PWV, can provide an accurate, stable reference for characterizing upper-troposphere water vapor. C1 NASA, Langley Res Ctr, SAIC, Hampton, VA 23681 USA. Sandia Natl Labs, Livermore, CA USA. Argonne Natl Lab, Argonne, IL 60439 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, Wallops Flight Facil, Wallops Isl, VA USA. Pacific NW Natl Lab, Richland, WA USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Wisconsin, Madison, WI USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Basilicata, DIFA, I-85100 Potenza, Italy. RP Ferrare, RA (reprint author), NASA, Langley Res Ctr, SAIC, Mail Stop 401A, Hampton, VA 23681 USA. EM richard.a.ferrare@nasa.gov RI Demoz, Belay/N-4130-2014; OI Lesht, Barry/0000-0003-0801-4290 NR 79 TC 39 Z9 39 U1 2 U2 3 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 DEC PY 2004 VL 21 IS 12 BP 1790 EP 1808 DI 10.1175/JTECH-1652.1 PG 19 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 885VD UT WOS:000226184300004 ER PT J AU Luo, ZZ Rossow, WB AF Luo, ZZ Rossow, WB TI Characterizing tropical cirrus life cycle, evolution, and interaction with upper-tropospheric water vapor using lagrangian trajectory analysis of satellite observations SO JOURNAL OF CLIMATE LA English DT Article ID HIGH-LEVEL CLOUDS; RADIATIVE PROPERTIES; INFRARED RADIANCES; TOP TEMPERATURE; OPTICALLY THIN; IMAGERS ISCCP; SOUNDERS 3I; SAGE-II; PART I; HUMIDITY AB Tropical cirrus evolution and its relation to upper-tropospheric water vapor (UTWV) are examined in the paper by analyzing satellite-derived cloud data, UTWV data from infrared and microwave measurements, and the NCEP-NCAR reanalysis wind field. Building upon the existing International Satellite Cloud Climatology Project (ISCCP) data and the Television and Infrared Observation Satellite ( TIROS) Operational Vertical Sounder (TOVS) product, a global ( except polar region), 6-hourly cirrus dataset is developed from two infrared radiance measurements at 11 and 12 m m. The UTWV is obtained in both clear and cloudy locations by developing a combined satellite infrared and microwave-based retrieval. The analysis in this study is conducted in a Lagrangian framework. The Lagrangian trajectory analysis shows that the decay of deep convection is immediately followed by the growth of cirrostratus and cirrus, and then the decay of cirrostratus is followed by the continued growth of cirrus. Cirrus properties continuously evolve along the trajectories as they gradually thin out and move to the lower levels. Typical tropical cirrus systems last for 19-30 +/- 16 h. This is much longer than cirrus particle lifetimes, suggesting that other processes (e.g., large-scale lifting) replenish the particles to maintain tropical cirrus. Consequently, tropical cirrus can advect over large distances, about 600-1000 km, during their lifetimes. For almost all current GCMs, this distance spans more than one grid box, requiring that the water vapor and cloud water budgets include an advection term. Based on their relationship to convective systems, detrainment cirrus are distinguished from in situ cirrus. It is found that more than half of the tropical cirrus are formed in situ well away from convection. The interaction between cirrus and UTWV is explored by comparing the evolution of the UTWV along composite clear trajectories and trajectories with cirrus. Cirrus are found to be associated with a moister upper troposphere and a slower rate of decrease of UTWV. Moreover, the elevated UTWV has a longer duration than cirrus. The amount of water in cirrus is too small for evaporation of cirrus ice particles to moisten the upper troposphere significantly (but cirrus may be an important water vapor sink). Rather, it is likely that the same transient motions that produce the cirrus also transport water vapor upward to maintain a larger UTWV. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. RP Rossow, WB (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM wrossow@giss.nasa.gov RI Rossow, William/F-3138-2015 NR 61 TC 93 Z9 93 U1 1 U2 2 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 DEC PY 2004 VL 17 IS 23 BP 4541 EP 4563 DI 10.1175/3222.1 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 876MP UT WOS:000225501400006 ER PT J AU Jones, C Waliser, DE Lau, KM Stern, W AF Jones, C Waliser, DE Lau, KM Stern, W TI Global occurrences of extreme precipitation and the Madden-Julian oscillation: Observations and predictability SO JOURNAL OF CLIMATE LA English DT Article ID OUTGOING LONGWAVE RADIATION; INTRASEASONAL CONVECTIVE ANOMALIES; EXTENDED-RANGE PREDICTION; ATLANTIC CONVERGENCE ZONE; AMERICAN-MONSOON-SYSTEM; LARGE-SCALE ENVIRONMENT; CUMULUS CLOUD ENSEMBLE; WESTERN UNITED-STATES; FORECAST MODEL; SOUTH-AMERICA AB This study investigates 1) the eastward propagation of the Madden-Julian oscillation (MJO) and global occurrences of extreme precipitation, 2) the degree to which a general circulation model with a relatively realistic representation of the MJO simulates its influence on extremes, and 3) a possible modulation of the MJO on potential predictability of extreme precipitation events. The observational analysis shows increased frequency of extremes during active MJO phases in many locations. On a global scale, extreme events during active MJO periods are about 40% higher than in quiescent phases of the oscillation in locations of statistically significant signals. A 10-yr National Aeronautics and Space Administration (NASA) Goddard Laboratory for the Atmospheres (GLA) GCM simulation with fixed climatological SSTs is used to generate a control run and predictability experiments. Overall, the GLA model has a realistic representation of extremes in tropical convective regions associated with the MJO, although some shortcomings also seem to be present. The GLA model shows a robust signal in the frequency of extremes in the North Pacific and on the west coast of North America, which somewhat agrees with observational studies. The analysis of predictability experiments indicates higher success in the prediction of extremes during an active MJO than in quiescent situations. Overall, the predictability experiments indicate the mean number of correct forecasts of extremes during active MJO periods to be nearly twice the correct number of extremes during quiescent phases of the oscillation in locations of statistically significant signals. C1 Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. SUNY Stony Brook, Inst Terr & Planetary Atmospheres, Stony Brook, NY 11794 USA. NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. Princeton Univ, Geophys Fluid Dynam Lab, Princeton, NJ 08544 USA. RP Jones, C (reprint author), Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. EM cjones@icess.ucsb.edu RI Lau, William /E-1510-2012; Jones, Charles/I-4574-2012 OI Lau, William /0000-0002-3587-3691; Jones, Charles/0000-0003-4808-6977 NR 57 TC 83 Z9 93 U1 2 U2 20 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 DEC PY 2004 VL 17 IS 23 BP 4575 EP 4589 DI 10.1175/3238.1 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 876MP UT WOS:000225501400008 ER PT J AU Kahn, BH Eldering, A Ghil, M Bordoni, S Clough, SA AF Kahn, BH Eldering, A Ghil, M Bordoni, S Clough, SA TI Sensitivity analysis of cirrus cloud properties from high-resolution infrared spectra. Part I: Methodology and synthetic cirrus SO JOURNAL OF CLIMATE LA English DT Article ID FINITE CIRCULAR-CYLINDERS; MU-M WINDOW; MICROPHYSICAL PROPERTIES; FIRE-II; INTERFEROMETER SOUNDER; RADIATIVE PROPERTIES; EFFECTIVE RADIUS; CLIMATE MODELS; RETRIEVAL; ICE AB A set of simulated high-resolution infrared ( IR) emission spectra of synthetic cirrus clouds is used to perform a sensitivity analysis of top-of-atmosphere ( TOA) radiance to cloud parameters. Principal component analysis ( PCA) is applied to assess the variability of radiance across the spectrum with respect to microphysical and bulk cloud quantities. These quantities include particle shape, effective radius ( r(eff)), ice water path ( IWP), cloud height Z(cld) and thickness DeltaZ(cld), and vertical profiles of temperature T( z) and water vapor mixing ratio w( z). It is shown that IWP variations in simulated cloud cover dominate TOA radiance variability. Cloud height and thickness, as well as T( z) variations, also contribute to considerable TOA radiance variability. The empirical orthogonal functions ( EOFs) of radiance variability show both similarities and differences in spectral shape and magnitude of variability when one physical quantity or another is being modified. In certain cases, it is possible to identify the EOF that represents variability with respect to one or more physical quantities. In other instances, similar EOFs result from different sets of physical quantities, emphasizing the need for multiple, independent data sources to retrieve cloud parameters. When analyzing a set of simulated spectra that include joint variations of IWP, r(eff), and w( z) across a realistic range of values, the first two EOFs capture approximately 92% - 97% and 2% - 6% of the total variance, respectively; they reflect the combined effect of IWP and r(eff). The third EOF accounts for only 1% - 2% of the variance and resembles the EOF from analysis of spectra where only w( z) changes. Sensitivity with respect to particle size increases significantly for r(eff) several tens of microns or less. For small-particle r(eff), the sensitivity with respect to the joint variation of IWP, r(eff), and w( z) is well approximated by the sum of the sensitivities with respect to variations in each of three quantities separately. C1 Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. Ecole Normale Super, Dept Terre Atmosphere Ocean, F-75231 Paris, France. Ecole Normale Super, Meteorol Dynam Lab, F-75231 Paris, France. Atmospher Environm Res Inc, Cambridge, MA 02139 USA. RP Univ Calif Los Angeles, Dept Atmospher & Ocean Sci, 405 Hilgard Ave,Box 951565, Los Angeles, CA 90095 USA. EM kahn@atmos.ucla.edu NR 64 TC 10 Z9 11 U1 0 U2 1 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 DEC PY 2004 VL 17 IS 24 BP 4856 EP 4870 DI 10.1175/JCLI-3220.1 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 884KZ UT WOS:000226084900017 ER PT J AU Perlwitz, J Harnik, N AF Perlwitz, J Harnik, N TI Downward coupling between the stratosphere and troposphere: The relative roles of wave and zonal mean processes SO JOURNAL OF CLIMATE LA English DT Article ID NORTHERN-HEMISPHERE; PLANETARY-WAVES; ARCTIC OSCILLATION; WIND ANOMALIES; VARIABILITY; WEATHER; MODEL; PROPAGATION; CIRCULATION; CONNECTION AB Wave and zonal mean features of the downward dynamic coupling between the stratosphere and troposphere are compared by applying a time-lagged singular value decomposition analysis to Northern Hemisphere height fields decomposed into zonal mean and its deviations. It is found that both zonal and wave components contribute to the downward interaction, with zonal wave 1 ( due to reflection) dominating on the short time scale ( up to 12 days) and the zonal mean ( due to wave-mean-flow interaction) dominating on the longer time scale. It is further shown that the two processes dominate during different years, depending on the state of the stratosphere. Winters characterized by a basic state that is reflective for wave 1 show a strong relationship between stratospheric and tropospheric wave-1 fields when the stratosphere is leading and show no significant correlations in the zonal mean fields. On the other hand, winters characterized by a stratospheric state that does not reflect waves show a strong relationship only between stratospheric and tropospheric zonal mean fields. This study suggests that there are two types of stratospheric winter states, characterized by different downward dynamic interaction. In one state, most of the wave activity gets deposited in the stratosphere, resulting in strong wave - mean-flow interaction, while in the other state, wave activity is reflected back down to the troposphere, primarily affecting the structure of tropospheric planetary waves. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY USA. Columbia Univ, Lamont Doherty Earth Observ, Dept Earth & Environm Sci, Palisades, NY USA. RP Perlwitz, J (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM judith@giss.nasa.gov RI Perlwitz, Judith/B-7201-2008 OI Perlwitz, Judith/0000-0003-4061-2442 NR 32 TC 60 Z9 64 U1 0 U2 8 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 DEC PY 2004 VL 17 IS 24 BP 4902 EP 4909 DI 10.1175/JCLI-3247.1 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 884KZ UT WOS:000226084900021 ER PT J AU Fairbridge, RW AF Fairbridge, RW TI Classification of coasts SO JOURNAL OF COASTAL RESEARCH LA English DT Article ID SEA-LEVEL; CLIMATIC-CHANGE; PENINSULA; ICE AB The simplest description of a given coast requires a minimum of three terms, embracing the following: (1) material (hard/soft; soluble or otherwise); (2) agencies (erosive/constructive; physical, chemical, biological, and geographic setting [latitude, exposure, fetch]), and (3) historical factors (time scale: geotectonic, glacioisostatic, eustatic, steric, anthropic). Deductive reasoning based on instrumental data such as tide gauges frequently lead to misleading conclusions, in that most are located in the northern hemisphere (land-dominated), near river mouths (variable runoff), sediment compaction, crustal lowering, coriolis effect of geostrophic current variation, and excessively short data spans (< 100 yr). Climatic oscillation influences sea level on all scales from ENSO (El Nino Southern Oscillation) and NAO (North Atlantic Oscillation) up to 1500 yr or more. Satellite observations furnish only the briefest "snap-shots." Classifications based on perceived "relative" relationships such as submergence or emergence are useful as generalizations, but only when provided with the time scale. Similar constraints apply to subsidence and uplift, and always subject to the three fundamental criteria. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Fairbridge, RW (reprint author), NASA, Goddard Inst Space Studies, New York, NY 10025 USA. NR 79 TC 15 Z9 17 U1 2 U2 5 PU COASTAL EDUCATION & RESEARCH FOUNDATION PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 0749-0208 J9 J COASTAL RES JI J. Coast. Res. PD WIN PY 2004 VL 20 IS 1 BP 155 EP 165 DI 10.2112/1551-5036(2004)20[155:COC]2.0.CO;2 PG 11 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Physical Geography; Geology GA 808DN UT WOS:000220549900013 ER PT J AU Norton, GV Novarini, JC AF Norton, GV Novarini, JC TI Including dispersion and attenuation in time domain modeling of pulse propagation in spatially-varying media SO JOURNAL OF COMPUTATIONAL ACOUSTICS LA English DT Article DE FDTD; dispersion; causality; propagation ID FREQUENCY POWER-LAW; WAVE-PROPAGATION; EQUATIONS AB Modeling of acoustic pulse propagation in nonideal fluids requires the inclusion of attenuation and its causal companion, dispersion. For the case of propagation in a linear, unbounded medium Szabo developed a convolutional propagation operator which, when introduced into the linear wave equation, accounts for attenuation and causal dispersion for any medium whose attenuation possesses a generalized Fourier transform. Utilizing a one dimensional Finite Difference Time Domain (FDTD) model Norton and Novarini showed that for an unbounded isotropic medium, the inclusion of this unique form of the convolutional propagation operator into the wave equation correctly carries the information of attenuation and dispersion into the time domain. This paper addresses the question whether or not the operator can be used as a basic building block for pulse propagation in a spatially dependent dispersive environment. The operator is therefore used to model 2-D pulse propagation in the presence of an interface separating two dispersive media. This represents the simplest description of a spatially dependent dispersive media. It was found that the transmitted and backscattered fields are in excellent agreement with theoretical expectations demonstrating the effectiveness of the local operator to model the field in spatially dependent dispersive media. [Work supported by ONR/NRL.] C1 USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. Planning Syst Inc, Long Beach, MS 39560 USA. RP Norton, GV (reprint author), USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. NR 14 TC 10 Z9 11 U1 1 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-396X J9 J COMPUT ACOUST JI J. Comput. Acoust. PD DEC PY 2004 VL 12 IS 4 BP 501 EP 519 DI 10.1142/S0218396X04002389 PG 19 WC Acoustics; Mathematics, Interdisciplinary Applications SC Acoustics; Mathematics GA 894TJ UT WOS:000226814200002 ER PT J AU Wang, Y Kostov, V Freese, K Frieman, JA Gondolo, P AF Wang, Y Kostov, V Freese, K Frieman, JA Gondolo, P TI Probing the evolution of the dark energy density with future supernova surveys SO JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS LA English DT Article DE dark energy theory; supernova type Ia; classical tests of cosmology ID ANGULAR POWER SPECTRUM; OBSERVATIONAL CONSTRAINTS; COSMOLOGICAL CONSTANT; CARDASSIAN EXPANSION; IA SUPERNOVAE; UNIVERSE; MATTER; MODEL; QUINTESSENCE; STATEFINDER AB The time dependence of the dark energy density can be an important clue to the nature of dark energy in the universe. We show that future supernova data from dedicated telescopes ( such as SNAP), when combined with data of nearby supernovae, can be used to determine how the dark energy density rho(X)(z) depends on redshift, if rho(X)( z) is not too close to a constant. For quantitative comparison, we have done an extensive study of a number of dark energy models. Based on these models we have simulated data sets in order to show that we can indeed reconstruct the correct sign of the time dependence of the dark energy density, outside of a degeneracy region centred on 1 + w(0) similar or equal to - w(1)z(max)/3 ( where z(max) is the maximum redshift of the survey; for example, z(max) = 1.7 for SNAP). C1 Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. Univ Michigan, Dept Phys, Michigan Ctr Theoret Phys, Ann Arbor, MI 48109 USA. Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Ctr Cosmol Phys, Chicago, IL 60637 USA. Univ Utah, Dept Phys, Salt Lake City, UT 84112 USA. RP Wang, Y (reprint author), Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. EM wang@nhn.ou.edu; kostov@nhn.ou.edu; ktfreese@umich.edu; frieman@fnal.gov; paolo@physics.utah.edu RI Wang, Yun/B-5724-2011 OI Wang, Yun/0000-0002-4749-2984 NR 54 TC 8 Z9 8 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1475-7516 J9 J COSMOL ASTROPART P JI J. Cosmol. Astropart. Phys. PD DEC PY 2004 IS 12 AR 003 DI 10.1088/1475-7516/2004/12/003 PG 24 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 884MI UT WOS:000226089000010 ER PT J AU Kadambi, JR Charoenngam, P Subramanian, A Wernet, MP Sankovic, JM Addie, G Courtwright, R AF Kadambi, JR Charoenngam, P Subramanian, A Wernet, MP Sankovic, JM Addie, G Courtwright, R TI Investigations of particle velocities in a slurry pump using PIV: Part 1, the tongue and adjacent channel flow SO JOURNAL OF ENERGY RESOURCES TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article ID CENTRIFUGAL PUMP; QUANTITATIVE VISUALIZATION; VOLUTE AB Transport of solid-liquid slurries in pipeline transport over short and medium distances is very important in many industries, including mining related processes. The particle image velocimetry technique was successfully utilized to investigate the velocities and kinetic energy fluctuations of slurry particles at the tongue region of an optically-clear centrifugal pump. The experiments were conducted using 500 micron glass beads at volumetric concentrations of 2.5% and 5% and at pump speeds of 725 rpm and 1000 rpm. The fluctuation kinetic energy increased approximately 200% to 500% as the pump speed was increased from 725 rpm to 1000 rpm. The directional impingement mechanism is more significant at the pressure side of the, blade, tongue and the casing. This mechanism becomes more important as the speed increases. This suggests that the impeller tongue and the casing of the slurry pump can wear out quickly, especially with an increase in speed. In this paper the emphasis is on the tongue region. The random impingement mechanism caused by the fluctuation kinetic energy of the solids can play an important role on the erosion of the tongue area. C1 Case Western Reserve Univ, Dept Mech & Aerosp Engn, Cleveland, OH 44106 USA. John Glenn Res Ctr, Natl Aeronaut & Space Adm, Cleveland, OH 44135 USA. Case Western Reserve Univ, Dept Biomed Engn, Cleveland, OH 44135 USA. GIW Ind, Grovetown, GA 30813 USA. RP Subramanian, A (reprint author), Case Western Reserve Univ, Dept Mech & Aerosp Engn, 10900 Euclid Ave, Cleveland, OH 44106 USA. NR 21 TC 8 Z9 9 U1 1 U2 9 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0195-0738 J9 J ENERG RESOUR-ASME JI J. Energy Resour. Technol.-Trans. ASME PD DEC PY 2004 VL 126 IS 4 BP 271 EP 278 DI 10.1115/1.1786928 PG 8 WC Energy & Fuels SC Energy & Fuels GA 887YG UT WOS:000226340800004 ER PT J AU Schneider, VI Healy, AF Barshi, I AF Schneider, VI Healy, AF Barshi, I TI Effects of instruction modality and readback on accuracy in following navigation commands SO JOURNAL OF EXPERIMENTAL PSYCHOLOGY-APPLIED LA English DT Article ID SHORT-TERM-MEMORY; OUTPUT; PERFORMANCE; RECALL; TASK AB In 3 experiments, the authors simulated air traffic controllers giving pilots navigation instructions of various lengths. Participants either heard or read the instructions; repeated either all, a reduced form, or none of the instructions; and then followed them by clicking on the specified locations in a space represented by grids on a computer screen. Execution performance for visual presentation was worse than it was for auditory presentation on the longer messages. Repetition of the instructions generally lowered execution performance for longer messages, which required more output, especially with the visual modality, which required phonological recoding from visual input to spoken output. An advantage for reduced over full repetition for visual but not for auditory presentation was attributed to an enhanced visual scanning process. C1 Univ Colorado, Dept Psychol, Boulder, CO 80309 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Schneider, VI (reprint author), Univ Colorado, Dept Psychol, 345 UCB, Boulder, CO 80309 USA. EM vickis@psych.colorado.edu NR 38 TC 13 Z9 13 U1 0 U2 2 PU AMER PSYCHOLOGICAL ASSOC PI WASHINGTON PA 750 FIRST ST NE, WASHINGTON, DC 20002-4242 USA SN 1076-898X J9 J EXP PSYCHOL-APPL JI J. Exp. Psychol.-Appl. PD DEC PY 2004 VL 10 IS 4 BP 245 EP 257 DI 10.1037/1076-898X.10.4.245 PG 13 WC Psychology, Applied SC Psychology GA 877EG UT WOS:000225550000004 PM 15598122 ER PT J AU Thrower, FP Hard, JJ Joyce, JE AF Thrower, FP Hard, JJ Joyce, JE TI Genetic architecture of growth and early life-history transitions in anadromous and derived freshwater populations of steelhead SO JOURNAL OF FISH BIOLOGY LA English DT Article; Proceedings Paper CT Annual Symposium of the Fisheries-Society-of-the-British-Isles CY JUL 19-23, 2004 CL London, ENGLAND SP Fisheries Soc British Isle DE growth; heritability; maturation; Oncorhynchus mykiss; precocious; smelting ID TROUT ONCORHYNCHUS-MYKISS; CHINOOK SALMON; RAINBOW-TROUT; MATURATION; INFORMATION; PARAMETERS; COMPONENTS; GAIRDNERI; SELECTION; RECOVERY AB Heritabilities of growth, precocious maturation and smolting were measured in 75 families of juvenile steelhead or rainbow trout Oncorhynchus mykiss, progeny of within and between line matings (crosses) of wild, anadromous steelhead and wild, resident (lake) rainbow trout originally derived from the same anadromous stock 70 years earlier. The tagged yearling progeny were combined by line in common freshwater rearing containers and graded into three categories: mature, smolt or rearing (undifferentiated) at age 2 years. Heritabilities of precocious male maturity, smelting and growth were moderate to high, and the genetic correlation between growth and smolting was low. Smolting and precocious male maturity were highly variable among families within lines and significantly different between lines. Each of the four lines produced significant numbers of smolts at age two. Smolting and maturation were negatively genetically correlated, which may explain the persistence of smolting in the lake population despite strong selection against lake smolts; balancing selection on male maturation age may help to maintain variation for smelting. The high heritability of smolting, coupled with the inability of smolts that leave the lake to return to it indicates that the genetic potential for smelting can lie dormant or be maintained through a dynamic interaction between smolting and early maturation for decades despite complete selection against the phenotype. The results have significant implications for the preservation of threatened anadromous stocks in fresh water and the inclusion of resident fish of formerly anadromous populations, currently trapped behind long-standing barriers to migration, as one component of the same population. (C) 2004 The Fisheries Society of the British Isles. C1 Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Auke Bay Lab, Juneau, AK 99801 USA. NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Conservat Biol Div, Seattle, WA USA. RP Thrower, FP (reprint author), Alaska Fisheries Sci Ctr, Natl Marine Fisheries Serv, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. EM frank.thrower@noaa.gov RI Hard, Jeffrey/C-7229-2009 NR 45 TC 62 Z9 63 U1 4 U2 22 PU BLACKWELL PUBLISHING PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DQ, OXON, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD DEC PY 2004 VL 65 SU A BP 286 EP 307 DI 10.1111/j.1095-8649.2004.00551.x PG 22 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 884WZ UT WOS:000226118700019 ER PT J AU Stoner, AW AF Stoner, AW TI Effects of environmental variables on fish feeding ecology: implications for the performance of baited fishing gear and stock assessment SO JOURNAL OF FISH BIOLOGY LA English DT Review DE active space; bait; CPUE; feeding biology; feeding motivation; stock assessment ID COD GADUS-MORHUA; HALIBUT REINHARDTIUS-HIPPOGLOSSOIDES; HADDOCK MELANOGRAMMUS-AEGLEFINUS; SABLEFISH ANOPLOPOMA-FIMBRIA; PLAICE PLEURONECTES-PLATESSA; JUVENILE SUMMER FLOUNDER; TUNA THUNNUS-OBESUS; LOCOMOTOR-ACTIVITY; REACTIVE DISTANCE; ATLANTIC SALMON AB The effectiveness of baited fishing gear ultimately depends upon behaviour of the target species activity rhythms, feeding motivation, and sensory and locomotory abilities. While any environmental parameter that mediates feeding or locomotion can have an important influence oil the active space presented by the bait and fish catchability, few biologists have considered how such variation in behaviour might affect catch per unit effort (CPUE) and the resultant stock abundance estimates or population parameters. This review reveals that environment-related variation in feeding behaviour can act through four different mechanisms: metabolic processes, sensory limitations, social interactions and direct impacts. Water temperature, light level, current velocity and ambient prey density are likely to have largest effects oil fish catchability, potentially affecting variation in CPUE by a factor of ten. Feeding behaviour is also density-dependent, with both positive and negative effects. Over time and geographic space a target species can occupy wide ranges of environmental conditions, and in certain cases, spatial and temporal variation in feeding biology could have a larger impact on CPUE than patterns of abundance. Temperature, light and current can be measured with relative facility and corrections to stock assessment models are feasible. Making corrections for biological variables such as prey density and bait competitors will be more difficult because the measurements are often not practical and relationships to feeding catchability are more complex and poorly understood. There is a critical need for greater understanding of how environmental variables affect feeding-related performance of baited fishing gear. A combination of field observations and laboratory experiments will be necessary to parameterize stock assessment models that are improved to accommodate variation in fish behaviour. Otherwise, survey data could reveal more about variation in behaviour than abundance trends. (C) 2004 The Fisheries Society of the British Isles. C1 NOAA, Alaska Fisheries Sci Ctr, Fisheries Behav Ecol Program, Natl Marine Fisheries Serv, Newport, OR 97365 USA. RP Stoner, AW (reprint author), NOAA, Alaska Fisheries Sci Ctr, Fisheries Behav Ecol Program, Natl Marine Fisheries Serv, 2030 S Marine Sci Dr, Newport, OR 97365 USA. EM al.stoner@noaa.gov NR 148 TC 85 Z9 87 U1 9 U2 31 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0022-1112 J9 J FISH BIOL JI J. Fish Biol. PD DEC PY 2004 VL 65 IS 6 BP 1445 EP 1471 DI 10.1111/j.1095-8649.2004.00593.x PG 27 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 885VH UT WOS:000226184700001 ER PT J AU Chin, TM Gross, RS Dickey, JO AF Chin, TM Gross, RS Dickey, JO TI Modeling and forecast of the polar motion excitation functions for short-term polar motion prediction SO JOURNAL OF GEODESY LA English DT Article DE polar motion; polar motion excitation; Kalman filtering ID AUTOCOVARIANCE PREDICTION; SPECTRUM ANALYSIS; ORIENTATION; EARTH; SERIES; TIME AB Short-term forecast of the polar motion is considered by introducing a prediction model for the excitation function that drives the polar motion dynamics. The excitation function model consists of a slowly varying trend, periodic modes with annual and several sub-annual frequencies (down to the 13.6-day fortnightly tidal period), and a transient decay function with a time constant of 1.5 days. Each periodic mode is stochastically specified using a second-order auto-regression process, allowing its frequency, phase, and amplitude to vary in time within a statistical tolerance. The model is used to time-extrapolate the excitation function series, which is then used to generate a polar motion forecast dynamically. The skills of this forecast method are evaluated by comparison to the C-04 polar motion series. Over the lead-time horizon of four months, the proposed method has performed equally well to some of the state-of-art polar motion prediction methods, none of which specifically features forecasting of the excitation function. The annual mode in the chi(2) component is energetically the most dominant periodicity. The modes with longer periods, annual and semi-annual in particular, are found to contribute more significantly to forecast accuracy than those with shorter periods. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chin, TM (reprint author), CALTECH, Jet Prop Lab, Mailstop 238-332,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM mike.chin@jpl.nasa.gov NR 22 TC 6 Z9 8 U1 1 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0949-7714 J9 J GEODESY JI J. Geodesy PD DEC PY 2004 VL 78 IS 6 BP 343 EP 353 DI 10.1007/s00190-004-0411-4 PG 11 WC Geochemistry & Geophysics; Remote Sensing SC Geochemistry & Geophysics; Remote Sensing GA 886NM UT WOS:000226235600001 ER PT J AU Koster, RD Suarez, MJ Liu, P Jambor, U Berg, A Kistler, M Reichle, R Rodell, M Famiglietti, J AF Koster, RD Suarez, MJ Liu, P Jambor, U Berg, A Kistler, M Reichle, R Rodell, M Famiglietti, J TI Realistic initialization of land surface states: Impacts on subseasonal forecast skill SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID GENERAL-CIRCULATION MODELS; GLOBAL SOIL-MOISTURE; DATA ASSIMILATION; JULY 1993; CLIMATE; PRECIPITATION; PREDICTION; PARAMETERIZATION; PREDICTABILITY; METHODOLOGY AB Forcing a land surface model (LSM) offline with realistic global fields of precipitation, radiation, and near-surface meteorology produces realistic fields ( within the context of the LSM) of soil moisture, temperature, and other land surface states. These fields can be used as initial conditions for precipitation and temperature forecasts with an atmospheric general circulation model (AGCM). Their usefulness is tested in this regard by performing retrospective 1-month forecasts ( for May through September, 1979 - 93) with the NASA Global Modeling and Assimilation Office (GMAO) seasonal prediction system. The 75 separate forecasts provide an adequate statistical basis for quantifying improvements in forecast skill associated with land initialization. Evaluation of skill is focused on the Great Plains of North America, a region with both a reliable land initialization and an ability of soil moisture conditions to overwhelm atmospheric chaos in the evolution of the meteorological fields. The land initialization does cause a small but statistically significant improvement in precipitation and air temperature forecasts in this region. For precipitation, the increases in forecast skill appear strongest in May through July, whereas for air temperature, they are largest in August and September. The joint initialization of land and atmospheric variables is considered in a supplemental series of ensemble monthly forecasts. Potential predictability from atmospheric initialization dominates over that from land initialization during the first 2 weeks of the forecast, whereas during the final 2 weeks, the relative contributions from the two sources are of the same order. Both land and atmospheric initialization contribute independently to the actual skill of the monthly temperature forecast, with the greatest skill derived from the initialization of both. Land initialization appears to contribute the most to monthly precipitation forecast skill. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Sci Applicat Int Corp, Beltsville, MD USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Lab Hydrospher Phys, Greenbelt, MD 20771 USA. Univ Guelph, Dept Geog, Guelph, ON N1G 2W1, Canada. Univ Calif Irvine, Irvine, CA USA. RP Koster, RD (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Mailstop 974-0, Greenbelt, MD 20771 USA. EM randal.koster@gsfc.nasa.gov RI Reichle, Rolf/E-1419-2012; Rodell, Matthew/E-4946-2012; Koster, Randal/F-5881-2012 OI Rodell, Matthew/0000-0003-0106-7437; Koster, Randal/0000-0001-6418-6383 NR 32 TC 106 Z9 110 U1 0 U2 11 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 DEC PY 2004 VL 5 IS 6 BP 1049 EP 1063 DI 10.1175/JHM-387.1 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 885VA UT WOS:000226184000003 ER PT J AU Rodell, M Houser, PR AF Rodell, M Houser, PR TI Updating a land surface model with MODIS-derived snow cover SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID GENERAL-CIRCULATION MODELS; WATER EQUIVALENT; VARIABILITY; DEPTH; OSCILLATION; SYSTEM; NAO AB A simple scheme for updating snow-water storage in a land surface model using snow cover observations is presented. The scheme makes use of snow cover observations retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Terra and Aqua satellites. Simulated snow-water equivalent is adjusted when and where the model and MODIS observation differ, following an internal accounting of the observation quality, by either removing the simulated snow or adding a thin layer. The scheme is tested in a 101-day global simulation of the Mosaic land surface model driven by the NASA/NOAA Global Land Data Assimilation System. Output from this simulation is compared to that from a control ( not updated) simulation, and both are assessed using a conventional snow cover product and data from ground-based observation networks over the continental United States. In general, output from the updated simulation displays more accurate snow coverage and compares more favorably with in situ snow time series. Both the control and updated simulations have serious deficiencies on occasion and in certain areas when and where the precipitation and/or surface air temperature forcing inputs are unrealistic, particularly in mountainous regions. Suggestions for developing a more sophisticated updating scheme are presented. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Rodell, M (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Code 974-1, Greenbelt, MD 20771 USA. EM Matthew.Rodell@nasa.gov RI Rodell, Matthew/E-4946-2012; Houser, Paul/J-9515-2013 OI Rodell, Matthew/0000-0003-0106-7437; Houser, Paul/0000-0002-2991-0441 NR 30 TC 106 Z9 114 U1 2 U2 17 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 DEC PY 2004 VL 5 IS 6 BP 1064 EP 1075 DI 10.1175/JHM-395.1 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 885VA UT WOS:000226184000004 ER PT J AU Hahn, I Weilert, M Zhong, F Barmatz, M AF Hahn, I Weilert, M Zhong, F Barmatz, M TI High-resolution measurements of the coexistence curve very near the He-3 liquid-gas critical point SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article DE He-3 coexistence curve; gravity effect; critical phenomena; equation-of-state ID VAPOR CRITICAL-POINT; CRITICAL EXPONENTS; DIELECTRIC-CONSTANT; DENSITY; TEMPERATURE; FLUID AB The shape of the liquid gas coexistence curve of He-3 very near the critical point temperature T-c was measured in the range -5 x 10(-3) < T/T-c - 1< -1.5 x 10(-6) using the quasistatic thermogram method. This study was performed in the Earth's gravitational field using two cells of very different heights (0.5 and 48 mm). The measured coexistence curve near the critical point was strongly affected by the gravitational field. Away from the critical point, we compare the coexistence curve obtained using the thermogram method with earlier work by Pittman et al. The recently developed crossover parametric model of the equation-of-state is used to take gravity effects into account. The shape of the measured coexistence curve very near the critical point is remarkably symmetric about the critical density. Our results close to the critical point are consistent with the slope of the rectilinear diameter obtained by Pitman et al. from measurement farther away from T-c. The deviation from a law, of rectilinear diameter predicted by revised scaling and the Yang-Yang anomaly were not observed in He-3 within the 0.1% accuracy in our measurements. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hahn, I (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Inseob.Hahn@jpl.nasa.gov NR 27 TC 8 Z9 8 U1 0 U2 1 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 DEC PY 2004 VL 137 IS 5-6 BP 579 EP 598 DI 10.1007/s10909-004-0893-8 PG 20 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 882WJ UT WOS:000225970800002 ER PT J AU Miller, CE Brown, LR AF Miller, CE Brown, LR TI Near infrared spectroscopy of carbon dioxide I.(OCO)-O-16-C-12-O-16 line positions SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE calibration standards; carbon dioxide; near-infrared; positions ID HETERODYNE FREQUENCY MEASUREMENTS; SEQUENCE BAND TRANSITIONS; HIGH VIBRATIONAL LEVELS; WAVE-NUMBER STANDARDS; EMISSION FT SPECTRA; 2 MU-M; MOLECULAR-CONSTANTS; ABSORPTION-BANDS; 4.5-MU-M REGION; ROVIBRATIONAL INTENSITIES AB High-resolution near-infrared (4000-9000 cm(-1)) spectra of carbon dioxide have been recorded using the McMath-Pierce Fourier transform spectrometer at the Kitt Peak National Solar Observatory. Some 2500 observed positions have been used to determine spectroscopic constants for 53 different vibrational states of the (OCO)-O-16-C-12-O-16 isotopologue, including eight vibrational states for which laboratory spectra have not previously been reported. Calibration by simultaneous use of CO near 4200cm(-1) and C F[2 near 6500cm(-1) provides absolute line position accuracies of 6.0 x 10(-5) cm(-1) (RMS) for strong, isolated transitions throughout the observed range. Fits with RMS errors <3.8 x 10(-5) cm(-1) have been obtained for the 20013 <-- 00001, 20012 <-- 00001, and 20011 <-- 00001 bands. RMS errors <6 x 10(-5) cm(-1) have been obtained for the 30014 <-- 00001, 30013 <-- 00001, 30012 <-- 00001, and 00031 <-- 00001 bands. and RMS errors < 5 x 10(-4) cm(-1) for even the weakest fitted bands. This work reduces CO2 near-infrared line position uncertainties by a factor of 10 or more compared to the 2000 HITRAN line list, which has not been modified since the comprehensive work of Rothman et al. [J. Quant. Spectrosc. Rad. Transfer 48 (1992) 537]. The new line list satisfies the line position accuracies required for the next generation of CO2 remote sensing instruments, improves the capability of solar-viewing spectrorneters to retrieve precise column CO2 measurements, and provides a secondary frequency standard in the near-infrared. (C) 2003 Elsevier Inc. All rights reserved. C1 Haverford Coll, Dept Chem, Haverford, PA 19041 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Miller, CE (reprint author), Haverford Coll, Dept Chem, Haverford, PA 19041 USA. EM charles.e.miller@jpl.nasa.gov NR 71 TC 88 Z9 87 U1 0 U2 16 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD DEC PY 2004 VL 228 IS 2 BP 329 EP 354 DI 10.1016/j.jms.2003.11.001 PG 26 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 869ES UT WOS:000224966800012 ER PT J AU Miller, CE Montgomery, MA Onorato, RM Johnstone, C McNicholas, TP Kovaric, B Brown, LR AF Miller, CE Montgomery, MA Onorato, RM Johnstone, C McNicholas, TP Kovaric, B Brown, LR TI Near infrared spectroscopy of carbon dioxide. II :(OCO)-O-16-C-13-O-16 and (OCO)-O-16-C-13-O-18 line positions SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE carbon dioxide; CO2; high-resolution; near infrared; NIR; HITRAN ID MU-M; FREQUENCY MEASUREMENTS; SPECTRAL MEASUREMENTS; ABSOLUTE FREQUENCIES; LASING TRANSITIONS; ABSORPTION-BANDS; FOURIER SPECTRA; CO2; INTENSITIES; REGION AB High-resolution near-infrared (4000-8500 cm(-1)) spectra of C-13-enriched carbon dioxide have been recorded using the McMath-Pierce Fourier transform spectrometer at the Kitt Peak National Solar Observatory. We observed over 1000 line positions for the (OCO)-O-16-C-13-O-16 isotopologue, the majority of which have previously been observed only in spectra of the Venusian atmosphere [J. Mol. Spectrosc. 67 (1977) 304]. These have been analyzed to determine spectroscopic constants for 28 different vibrational states. The analysis yielded RIMS fitting residuals <1.5 X 10(-4) cm(-1) for the strongest bands and RMS residuals <5 x 10(-4) cm(-1) for most other fitted bands. A 5% 180-enrichment in the sample enabled us to observe 410 line positions from 5 near-infrared vibrational bands of the (OCO)-O-16-C-13-O-18 isotopologue. Analysis of the (OCO)-O-16-C-13-O-18 bands yielded RMS fitting residuals <2 x 10-4 cm(-1). Additionally, the first fits for the (OCO)-O-16-C-13-O-18 11101 <-- 01101 and 11102 <-- 01101 hot bands yielded RMS residuals of 2.3 x 10(-4) and 2.2 x 10(-4) cm(-1) respectively. Critical reevaluations of the spectroscopic constants for the low lying vibrational states for both isotopologues have been performed as part of the analysis. (C) 2004 Elsevier Inc. All rights reserved. C1 Haverford Coll, Dept Chem, Haverford, PA 19041 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Miller, CE (reprint author), Haverford Coll, Dept Chem, Haverford, PA 19041 USA. EM charles.e.miller@jpl.nasa.gov NR 37 TC 35 Z9 35 U1 1 U2 4 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD DEC PY 2004 VL 228 IS 2 BP 355 EP 374 DI 10.1016/j.jms.2004.07.013 PG 20 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 869ES UT WOS:000224966800013 ER PT J AU Xu, LH Lees, RM Wang, P Brown, LR Kleiner, I Johns, JWC AF Xu, LH Lees, RM Wang, P Brown, LR Kleiner, I Johns, JWC TI New assignments, line intensities, and HITRAN database for CH3OH at 10 mu m SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE methanol; infrared spectra; internal rotation; line positions; line intensities; torsional modeling ID MICROWAVE SIDE-BAND; TRANSFORM INFRARED-SPECTROSCOPY; SUBMILLIMETER-WAVE SPECTRUM; STRETCHING FUNDAMENTAL-BAND; SUB-DOPPLER SPECTROSCOPY; GASEOUS METHYL-ALCOHOL; DIODE-LASER SPECTRA; CO2-LASER LINES; ADDITIONAL MEASUREMENTS; ASTROPHYSICAL INTEREST AB The Fourier transform spectrum of CH3OH in the 10 mum region has been re-examined at higher pressure and path length than heretofore, as part of a program to provide comprehensive CH3OH spectral data for astrophysical and atmospheric applications. With the increase in spectral sensitivity, it has been possible to assign new torsionally excited nu(12) = 1 and nu(12) = 2 subbands plus further high-K, nu(12) = 0 subbands of the nu(8) CO-stretching band. Upper-state term values have been determined, and have been fitted to J(J divided by 1) power-series expansions in order to obtain the excited nu(8) substate origins. A variety of weaker subbands from other modes has also been identified in the 10 mum spectrum including nu(12) = 0, nu(12) = 1, and nu(12) = 0 <-- 1 torsional subbands of the nu(7) inplane CH3 rock, nu(12) = 0 <-- 1 and nu(12) = 0 <-- 2 torsional combination subbands of the nu(6) OH bend, and V-12 = 0 <-- 2 subbands of the nu(5) symmetric CH3 bend. Line intensities have been retrieved line-by-line from the spectra. A large set of "unperturbed" nu(8) transitions has been modeled using the same type of multi-parameter effective Hamiltonian employed successfully for the ground state, with inclusion of the intensities of a subset of the stronger nu(8) spectral lines in the fitting in order to obtain appropriate transition dipole terms. Together, a 10 mum methanol database in HITRAN format has been generated. (C) 2004 Elsevier Tnc. All rights reserved. C1 Univ New Brunswick, Dept Phys Sci, St John, NB E2L 4L5, Canada. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Paris 11, Lab Phys Mol & Applicat, F-91405 Orsay, France. Natl Res Council Canada, Steacie Inst Mol Sci, Ottawa, ON K1A 0R6, Canada. RP Xu, LH (reprint author), Univ New Brunswick, Dept Phys Sci, St John, NB E2L 4L5, Canada. EM xuli@unb.ca RI Xu, Li-Hong/J-5095-2015 NR 39 TC 31 Z9 31 U1 2 U2 10 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD DEC PY 2004 VL 228 IS 2 BP 453 EP 470 DI 10.1016/j.jms.2004.05.017 PG 18 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 869ES UT WOS:000224966800020 ER PT J AU Devi, VM Predoi-Cross, A Benner, DC Smith, MAH Rinsland, CP Mantz, AW AF Devi, VM Predoi-Cross, A Benner, DC Smith, MAH Rinsland, CP Mantz, AW TI Self- and H-2-broadened width and shift coefficients in the 2 <- 0 band of (CO)-C-12-O-16 : revisited SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE CO; self- and H-2-pressure broadening and shifts; Fourier transform infrared spectroscopy ID VIBRATIONAL FREQUENCY PERTURBATIONS; INDUCED LINE SHIFTS; FUNDAMENTAL-BAND; GASEOUS HYDROGEN; RAMAN SPECTRUM; HALF-WIDTHS; CO; PARAMETERS; RELEVANT; 2-0-BAND AB Room temperature values for self-broadened and hydrogen-broadened Lorentz halfwidth coefficients, and self and hydrogen pressure-induced shift coefficients have been measured for transitions with rotational quantum number m ranging between -24 and 24 in the 2 <-- 0 band of (CO)-C-12-O-16. The spectra were recorded with the McMath-Pierce Fourier transform spectrometer located at the National Solar Observatory on Kitt Peak. The analysis was performed using a multispectrum nonlinear least squares technique. We have compared our results with similar measurements published recently. (C) 2004 Elsevier Inc. All rights reserved. C1 Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. Univ Lethbridge, Dept Phys, Lethbridge, AB T1K 3M4, Canada. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Connecticut Coll, Dept Phys Astron & Geophys, New London, CT 06320 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 22 TC 5 Z9 5 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 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD DEC PY 2004 VL 228 IS 2 BP 580 EP 592 DI 10.1016/j.jms.2004.05.006 PG 13 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 869ES UT WOS:000224966800028 ER PT J AU Benner, DC Blake, TA Brown, LR Devi, VM Smith, MAH Toth, RA AF Benner, DC Blake, TA Brown, LR Devi, VM Smith, MAH Toth, RA TI Air-broadening parameters in the nu(3) band of (NO2)-N-14-O-16 using a multispectrum fitting technique SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE NO2; air broadening; pressure shifts; temperature dependence; infrared; v(3) ID TEMPERATURE-DEPENDENCE; FREQUENCY-SHIFTS; NITROGEN-DIOXIDE; LINE PARAMETERS; SPECTRAL REGION; WATER-VAPOR; V(1) BAND; NO2; INTENSITIES; COEFFICIENTS AB Air-broadened linewidths, pressure-induced shift coefficients and their temperature dependences were retrieved for over 1000 transitions in the v(3) band of (NO2)-N-14-O-16 at 6mum. In addition, precise line center positions and relative intensities were also determined. The results were obtained by fitting simultaneously 27 spectra recorded at high resolution (0.002-0.006cm(-1)) with two Fourier transform spectrometers and gas sample temperatures ranging from 206 to 298K. It was necessary to modify the multispectrum fitting software to accommodate constraints on the retrieved parameters of closely spaced spin-split doublets in order to successfully determine their broadening and shift parameters. The variations of the widths, shifts and their temperature dependences with the quantum numbers were investigated. Subsets of the observed linewidths were reproduced to within 3% using an empirical smoothing function. (C) 2004 Elsevier Inc. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Coll William & Mary, Williamsburg, VA 23187 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Brown, LR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM linda.brown@jpl.nasa.gov NR 33 TC 8 Z9 8 U1 0 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD DEC PY 2004 VL 228 IS 2 BP 593 EP 619 DI 10.1016/j.jms.2004.07.006 PG 27 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 869ES UT WOS:000224966800029 ER PT J AU Pickett, HM AF Pickett, HM TI Spin eigenfunctions and operators for the D-n groups SO JOURNAL OF MOLECULAR SPECTROSCOPY LA English DT Article DE hyperfine; symmetry AB An automated procedure for determining symmetry-adapted spin eigenfunctions is developed for the D,, symmetry groups with 17 equivalent spins for arbitrary size of l and for n = 3,..., 6. These eigenfunctions are also eigenfunctions of the vector sum of the 11 equivalent nuclear spins. Generalized hyperfine spin operators are developed that have real matrix elements and that exploit the full symmetry. These spin operators can be combined with operators for other spins and molecular rotation using only real arithmetic. (C) 2004 Elsevier Inc. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Pickett, HM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Herbert.M.Pickett@jpl.nasa.gov NR 7 TC 5 Z9 5 U1 0 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-2852 J9 J MOL SPECTROSC JI J. Mol. Spectrosc. PD DEC PY 2004 VL 228 IS 2 BP 659 EP 663 DI 10.1016/j.jms.2004.05.012 PG 5 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 869ES UT WOS:000224966800034 ER PT J AU Vander Wal, R Tomasek, AJ Pamphlet, MI Taylor, CD Thompson, WK AF Vander Wal, R Tomasek, AJ Pamphlet, MI Taylor, CD Thompson, WK TI Analysis of HRTEM images for carbon nanostructure quantification SO JOURNAL OF NANOPARTICLE RESEARCH LA English DT Article DE carbon; nanostructure; HRTEM (high resolution transmission electron microscopy); image processing; soots ID ELECTRON-MICROSCOPY; RAMAN-SPECTROSCOPY; COMBUSTION; GRAPHITE; NANOFIBERS; FULLERENES; ADSORPTION AB Image processing algorithms have been developed to extract fringe length, tortuosity and separation from high resolution transmission electron microscopy images. To validate the separation algorithm, a comparison is made between the image-based fringe separation and that obtained by analysis of X-ray diffraction data for a progressively heat-treated carbon black. Agreement is favorable. To illustrate the utility of the analysis parameters for a range of carbon nanostructures, analysis is applied to a series of pyrolytically prepared carbon soots-qualitatively described as containing amorphous, graphitic or fullerenic nanostructure. For all processing, the intermediate image, in the form of a skeletonized binary image of the original high resolution transmission electron micrograph, is shown and found to accurately reflect the nanostructural organization within the carbon as visually observed. Statistical results for each analysis parameter, extracted from the binary images, are presented in the form of histograms and quantitatively distinguish the different carbon nanostructures. C1 NASA Glenn, NCMR, Cleveland, OH 44135 USA. RP Vander Wal, R (reprint author), NASA Glenn, NCMR, MS 110-3,21000 Brookpk Rd, Cleveland, OH 44135 USA. EM randy@rvander.grc.nasa.gov NR 40 TC 48 Z9 48 U1 3 U2 16 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1388-0764 J9 J NANOPART RES JI J. Nanopart. Res. PD DEC PY 2004 VL 6 IS 6 BP 555 EP 568 DI 10.1007/s11051-004-3724-6 PG 14 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary SC Chemistry; Science & Technology - Other Topics; Materials Science GA 907RL UT WOS:000227735500002 ER PT J AU Teague, WJ Jacobs, GA Mitchell, DA Wimbush, M Watts, DR AF Teague, WJ Jacobs, GA Mitchell, DA Wimbush, M Watts, DR TI Decadal current variations in the southwestern Japan/East Sea SO JOURNAL OF OCEANOGRAPHY LA English DT Article DE Japan Sea; Ulleung Basin; currents; TOPEX; PIES; East Korean Warm Current (EKWC); Ulleung Warm Eddy; Offshore Branch; marginal sea oceanography ID GLOBAL OCEAN TIDES; GEOSAT ALTIMETRY; VARIABILITY; ENERGETICS; PROFILES; ATLANTIC; STRAIT AB Absolute geostrophic velocities were calculated along TOPEX/Poseidon (T/P) groundtracks located in the Ulleung Basin of the southwestern Japan/East Sea (JES) from a combined analysis of nearly a decade of T/P data and two years of pressuregauge-equipped inverted echo sounder (PIES) data obtained during the United States Office of Naval Research's JES Program. Geostrophic velocities have been calculated daily for the Ulleung Basin from June 1999 to July 2001 from a three-dimensional mapping of temperature and salinity produced by PIES data interpreted via the Gravest Empirical Mode (GEM) technique combined with the Navy's Modular Ocean Data Assimilation System (MODAS). These velocities were then used to convert T/P velocity anomalies to absolute velocities for the T/P time period of 1993 to 2002. Current intensities and variabilities associated with the East Korean Warm Current, Ulleung Warm Eddy, and Offshore Branch are examined. Spatial and temporal variations of the sea surface circulation are strong. Intensification of the currents generally occurred during the fall season. The flow pattern in individual years differed greatly from year to year and differed from climatology in important qualitative ways. C1 USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. RP Teague, WJ (reprint author), USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. EM teague@nrlssc.navy.mil RI Jacobs, Gregg/C-1456-2008 NR 46 TC 3 Z9 3 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0916-8370 J9 J OCEANOGR JI J. Oceanogr. PD DEC PY 2004 VL 60 IS 6 BP 1023 EP 1033 DI 10.1007/s10872-005-0010-x PG 11 WC Oceanography SC Oceanography GA 866PJ UT WOS:000224785100010 ER PT J AU Vandemark, D Chapron, B Sun, J Crescenti, GH Graber, HC AF Vandemark, D Chapron, B Sun, J Crescenti, GH Graber, HC TI Ocean wave slope observations using radar backscatter and laser altimeters SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID SEA-SURFACE SLOPE; WIND-DRIVEN WAVES; MEAN-SQUARE SLOPE; MICROWAVE BACKSCATTER; OFFSHORE FLOW; CROSS-SECTION; SPEED; STRESS; DEPENDENCE; SPECTRA AB Combination of laser and radar aboard an aircraft is used to directly measure long gravity wave surface tilting simultaneously with nadir-viewing microwave backscatter from the sea surface. The presented dataset is extensive, encompassing varied wind conditions over coastal and open-ocean wave regimes. Laser-derived slope statistics and Ka-band (36 GHz) radar backscatter are detailed separately to document their respective variations versus near-surface wind speed. The slope statistics, measured for lambda > 1-2 m, show good agreement with Cox and Munk's oil-slickened sea measurements. A notable exception is elevated distribution peakedness and an observed wind dependence in this likely proxy for nonlinear wave-wave interactions. Aircraft Ka-band radar data nearly mimic Ku-band satellite altimeter observations in their mean wind dependence. The present calibrated radar data, along with relevant observational and theoretical studies, suggest a large (25 dB) bias in previous Ka-band results. Next, wave-diverse inland, coastal, and open-ocean observations are contrasted to show wind-independent long-wave slope variance changes of a factor of 2-3, always increasing as one heads to sea. Combined long-wave and radar data demonstrate that this long-wave tilt field variability is largely responsible for radar backscatter variations observed at a given wind speed, particularly at wind speeds below 5-7 m s(-1). Results are consistent with, and provide quantititative support for, recent satellite altimeter studies eliciting signatures of long-wave impacts resident in the radar backscatter. Under a quasi-optical scattering assumption, the results illustrate long-wave control on the variance of the total mean square slope parameter due to changes in the directional long-wave spectrum, with high-wavenumbers being relatively unaffected in a mean sense. However, further analysis suggests that for winds above 7 m s(-1) the high-wavenumber subrange also varies with change in the longer wave field slope and/or energy, the short gravity wave roughness being measurably greater for smoother C1 NASA, Goddard Space Flight Ctr, Wallops Isl, VA 23337 USA. IFREMER, Dept Oceanog Spatiale, Plouzane, France. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NOAA, Field Res Div, Idaho Falls, ID USA. Univ Miami, Miami, FL 33152 USA. RP Ocean Proc Anal Lab, 39 Coll Rd,142 Morse Hall, Durham, NH 03824 USA. EM douglas.vandemark@nasa.gov RI Sun, Jielun/H-6576-2015; Chapron, Bertrand/O-6527-2015 OI Sun, Jielun/0000-0003-3271-7914; NR 51 TC 63 Z9 64 U1 0 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 EI 1520-0485 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD DEC PY 2004 VL 34 IS 12 BP 2825 EP 2842 DI 10.1175/JPO2663.1 PG 18 WC Oceanography SC Oceanography GA 889RA UT WOS:000226458900018 ER PT J AU Liao, L Pang, Y Ding, LM Karasz, FE Smith, PR Meador, MA AF Liao, L Pang, Y Ding, LM Karasz, FE Smith, PR Meador, MA TI Synthesis and luminescence of yellow/orange-emitting poly [tris(2,5-dihexyloxy-1,4-phenylenevinylene)alt-(1,3-phenylenevinylene)]s SO JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY LA English DT Article DE conjugated polymers; light-emitting diodes; luminescence ID STRUCTURE-PROPERTY RELATIONSHIPS; CONJUGATED POLYMERS; ELECTROLUMINESCENT POLYMERS; VINYLENE COPOLYMERS; OPTICAL-PROPERTIES; LIGHT; DIODES; POLY(M-PHENYLENEVINYLENE-CO-2,5-DIOCTYLOXY-P-PHENYLENEVINYLENE); EFFICIENCY; LENGTH AB Soluble yellow/orange-emitting poly [tris(2,5-dihexyloxy-1,4-phenylenevinylene)-alt-(1,3-phenylenevinylene)] derivatives (6) were synthesized and characterized. These polymers contained oligo(p-phenylene vinylene) chromophores of equal conjugation length, which were jointed via a common m-phenylene unit. An optical comparison of 6 and its model compound (8) at room temperature and low temperatures revealed the similarity in their absorption and fluorescence band structures. The vibronic band structure of 6 was assigned with the aid of the spectroscopic data for 8 at the low temperatures. 6 was electroluminescent and had an emission maximum wavelength at approximately 565 nm. With the device indium tin oxide/PEDOT/6/Ca configuration, the polymer exhibited an external quantum efficiency as high as 0.25%. Simple substitution on rn-phenylene of 6 raised the electroluminescence output by a factor of about 10. (C) 2004 Wiley Periodicals, Inc. C1 Clark Atlanta Univ, Dept Chem, Atlanta, GA 30314 USA. Clark Atlanta Univ, Ctr High Performance Polymers & Composites, Atlanta, GA 30314 USA. Univ Massachusetts, Dept Polymer Sci & Engn, Amherst, MA 01003 USA. NASA, John H Glenn Res Ctr, Div Mat, Cleveland, OH 44135 USA. RP Pang, Y (reprint author), Clark Atlanta Univ, Dept Chem, Atlanta, GA 30314 USA. EM ypang@cau.edu RI Ding, Liming/C-6050-2013 NR 30 TC 13 Z9 14 U1 1 U2 2 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0887-624X J9 J POLYM SCI POL CHEM JI J. Polym. Sci. Pol. Chem. PD DEC 1 PY 2004 VL 42 IS 23 BP 5853 EP 5862 DI 10.1002/pola.20425 PG 10 WC Polymer Science SC Polymer Science GA 872IQ UT WOS:000225201300002 ER PT J AU Wu, LG Braun, SA AF Wu, LG Braun, SA TI Effects of environmentally induced asymmetries on hurricane intensity: A numerical study SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID VORTEX ROSSBY-WAVES; SIMULATED TROPICAL CYCLONE; POTENTIAL VORTICITY; SPIRAL BANDS; PART I; EDDY FLUXES; MODEL; INTENSIFICATION; FLOW; EVOLUTION AB The influence of uniform large-scale flow, the beta effect, and vertical shear of the environmental flow on hurricane intensity is investigated in the context of the induced convective or potential vorticity asymmetries in the core region with a hydrostatic primitive equation hurricane model. In agreement with previous studies, imposition of one of these environmental effects weakens the simulated tropical cyclones. In response to the environmental influence, significant wavenumber-1 asymmetries develop. Asymmetric and symmetric tendencies of the mean radial and azimuthal winds and temperature associated with the environment-induced convective asymmetries are evaluated. The inhibiting effects of environmental influences are closely associated with the resulting eddy momentum fluxes, which tend to decelerate tangential and radial winds in the inflow and outflow layers. The corresponding changes in the symmetric circulation tend to counteract the deceleration effect. The net effect is a moderate weakening of the mean tangential and radial winds. The reduced radial wind can be viewed as an anomalous secondary radial circulation with inflow in the upper troposphere and outflow in the lower troposphere, weakening the mean secondary radial circulation. C1 NASA, Atmospheres Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth & Technol Ctr, Baltimore, MD 21228 USA. RP Wu, LG (reprint author), NASA, Atmospheres Lab, Goddard Space Flight Ctr, Code 912, Greenbelt, MD 20771 USA. EM liguang@agnes.gsfc.nasa.gov NR 50 TC 38 Z9 40 U1 0 U2 4 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 DEC PY 2004 VL 61 IS 24 BP 3065 EP 3081 DI 10.1175/JAS-3343.1 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 881KK UT WOS:000225866200007 ER PT J AU Chen, CS Chen, WC Tao, WK AF Chen, CS Chen, WC Tao, WK TI Characteristics of heavy summer rainfall in southwestern Taiwan in relation to orographic effects SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article ID AIR-FLOW; PRECIPITATION SYSTEMS; NUMERICAL SIMULATIONS; CLOUD DISTRIBUTIONS; MESOSCALE MODEL; WINDWARD SIDE; COLD-FRONT; ISLAND; HAWAII; TAMEX AB About a quarter to a half of all rainfall from mid-July through August from 1994 to 2000, on the windward side of southwestern Taiwan, came from convective systems embedded in the monsoon flow associated with the southwesterly monsoon. In this study, the causes of two heavy rainfall events (daily rainfall exceeding 100 mm day(-1) over at least three rainfall stations), observed over the slopes and/or lowlands of southwestern Taiwan were examined. Data from the European Center for Medium-Range Weather Forecasts/Tropical Ocean-Global Atmosphere (EC/TOGA) analyses, the rainfall stations of the Automatic Rainfall and Meteorological Telemetry System (ARMTS) and the conventional surface stations over Taiwan, and the simulation results from a regional-scale numerical model were used to accomplish the objectives. In one event, on 9 August 1999, heavy rainfall of up to 393 mm was observed over the windward slopes of southern Taiwan in a potentially unstable environment, with very humid air around 850 hPa. The extreme accumulation was simulated and attributed to orographic lifting effects as preexisting convection did not drift into western Taiwan from the Taiwan Strait. In another event, on 13 August 1994, with a maximum rainfall of 450 mm, westerly flow with potentially unstable and very moist air in the lowest layers, converged with northwesterly flow from the central Taiwan Strait over the southwestern coast. The westerly flow decelerated while approaching Taiwan, resulting in enhanced convergence and upward motion over the coastal area and a high amount of rainfall. In addition, a mesoscale convergence area was produced over the southern Taiwan Strait near the southwestern coast of Taiwan due to synoptic circulations. Some convection formed in the ocean near the southwest coast and drifted inland. This situation also enhanced precipitation over the coastal areas. Northwesterly flow formed over the southwestern slopes as weak westerly flow approached the mountains. As rainwater from the Strait and coastal areas moved eastward toward the slopes, the northwesterly flow transported the rainwater southeastward away from the southwestern slopes. Subsequently, less rainfall occurred over the southwestern slopes than over the coastal areas. C1 Natl Cent Univ, Inst Atmospher Phys, Chungli 320, Taiwan. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD USA. RP Chen, CS (reprint author), Natl Cent Univ, Inst Atmospher Phys, Chungli 320, Taiwan. EM tchencs@atm.ncu.edu.tw NR 32 TC 9 Z9 9 U1 0 U2 3 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 DEC PY 2004 VL 82 IS 6 BP 1521 EP 1543 DI 10.2151/jmsj.82.1521 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 892CX UT WOS:000226628500003 ER PT J AU Sun, WY Chern, JD Bosilovich, M AF Sun, WY Chern, JD Bosilovich, M TI Numerical study of the 1988 drought in the United States SO JOURNAL OF THE METEOROLOGICAL SOCIETY OF JAPAN LA English DT Article; Proceedings Paper CT 2nd Workshop on Regional Climate Modeling for Monson Systems CY MAR 04-06, 2003 CL Frontier Res Syst Global Change Japan Acgy Marine-Earth Sci & Technol, Yokohama, JAPAN SP GAME, Int Sci Panel, GISP, FRSGC, FRSOGC HO Frontier Res Syst Global Change Japan Acgy Marine-Earth Sci & Technol ID NORTH-AMERICAN DROUGHT; SOIL-MOISTURE; CUMULUS CONVECTION; CLOUD MODEL; PARAMETERIZATION; SUMMER; SIMULATION; PREDICTION; PROJECT; SCHEME AB During the summer of 1988, a severe drought caused extensive loss of crops in the Midwest and Gulf States of the United States. The Purdue Regional Model (PRM), with comprehensive atmospheric physics and soil-vegetation surface package, has been integrated continuously for thirty days of June 1988 to study circulation and surface hydrology. The results show that the PRM is capable of reproducing the evolution of the observed weather and monthly mean fields of June 1988, when an extensive ridge located over the hot, dry North America suppressed the moisture supply from the oceans. Sensitivity test shows that under the observed SST and large-scale wave pattern, the model can generate more precipitation using wet soil as the initial condition, but a strong stationary anticyclone still exists in the US. The wet soil also enhances anticyclonic circulation centered over the Rocky Mountains, and the offshore flow in Texas and Gulf States, soil becomes dry eventually. Hence, the dry soil over the central US alone is insufficient to instigate the anomalous warm ridge, but could have had a role in its persistent drought due to the weakening of the low-level jet in Texas and Oklahoma region and less evaporation from the land surface. C1 Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. RP Sun, WY (reprint author), Purdue Univ, Dept Earth & Atmospher Sci, 550 Stadium Mall Dr, W Lafayette, IN 47907 USA. EM wysun@purdue.edu RI Bosilovich, Michael/F-8175-2012 NR 38 TC 5 Z9 5 U1 2 U2 4 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 DEC PY 2004 VL 82 IS 6 BP 1667 EP 1678 DI 10.2151/jmsj.82.1667 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 892CX UT WOS:000226628500012 ER PT J AU Stanford, MK DellaCorte, C Eylon, D AF Stanford, MK DellaCorte, C Eylon, D TI Effect of particle morphology on flow characteristics of a composite plasma spray powder SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article DE coatings; particle morphology; plasma spray coatings; powder flowability solid lubrication AB The effects of BaF2-CaF2 particle morphology on National Aeronautics and Space Administration (NASA) PS304 feedstock powder flowability were investigated. BaF2-CaF2 eutectic powders were fabricated by comminution (producing an angular morphology) and by gas atomization (producing a spherical morphology). The fluoride powders were added incrementally to the other powder constituents of the NASA PS304 feedstock, (Ni-Cr, Cr2O3, and Ag powders). A linear relationship between flow time and concentration of the BaF2-CaF2 powder was found. The flow of the powder blend with spherical BaF2-CaF2 was better than that with angular BaF2-CaF2. The flowability of the powder blend with angular fluorides decreased linearly with increasing fluoride concentration. However, the flow of the powder blend with spherical fluorides was independent of fluoride concentration. The results suggest that for this material blend, particle morphology plays a significant role in flow behavior, offering potential methods to improve powder flowability and entrance the commercial potential. These findings may be applicable to other difficult-to-flow powders such as cohesive ceramics. C1 Univ Dayton, Dayton, OH 45469 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Stanford, MK (reprint author), Univ Dayton, Dayton, OH 45469 USA. EM Malcolm.K.Stanford@nasa.gov NR 28 TC 9 Z9 9 U1 1 U2 7 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD DEC PY 2004 VL 13 IS 4 BP 586 EP 592 DI 10.1361/10599630421505 PG 7 WC Materials Science, Coatings & Films SC Materials Science GA 884KA UT WOS:000226082400022 ER PT J AU Harms, CA Papich, MG Stamper, A Ross, PM Rodriguez, MX Hohn, AA AF Harms, CA Papich, MG Stamper, A Ross, PM Rodriguez, MX Hohn, AA TI Pharmacokinetics of oxytetracycline in loggerhead sea turtles (Caretta caretta) after single intravenous and intramuscular injections SO JOURNAL OF ZOO AND WILDLIFE MEDICINE LA English DT Article DE biologic marker; Caretta caretta; loggerhead sea turtle; oxytetracycline; pharmacokinetics ID ALLIGATORS ALLIGATOR-MISSISSIPPIENSIS; MYCOPLASMA-ALLIGATORIS; PLASMA-CONCENTRATIONS; GROWTH; SKELETOCHRONOLOGY; CHLAMYDIOSIS AB The pharmacokinetics of oxytetracycline in 2-yr-old loggerhead sea turtles (Caretta caretta) after single i.v. and i.m. injections were studied for biologic marking and therapeutic applications. Twenty juvenile turtles were divided into two treatment groups. Ten animals received 25 mg/kg of oxytetracycline i.v. and 10 received the same dosage i.m. Plasma oxytetracycline concentrations were analyzed by reverse-phase high-performance liquid chromatography. Data from the i.v. route best fit a three-compartment model, whereas noncompartmental analysis was used to compare data front both the i.v. and i.m routes. For the i.v. route, means for maximum plasma concentration. terminal phase half-life, systemic clearance, and apparent volume of distribution at steady state were 6.6 mug/ml, 66.1 hr. 290.7 ml/hr/kg, and 18.4 L, respectively. For the i.m. route, means for systemic availability, maximum plasma concentration. and elimination half-life were 91.8%, 1.6 mug/ml, and 61.9 hr. respectively. The remarkably high apparent volume of distribution may possibly be associated with a deep compartment of drug disposition such as bone deposition associated with the large skeletal mass of turtles and the fact that these were well-nourished, growing juveniles. Although maximum plasma concentration by i.m. administration was lower than for the i.v. route, the long elimination time indicates that an infrequent closing interval may be effective for sensitive bacteria. C1 N Carolina State Univ, Environm Consortium, Raleigh, NC 27606 USA. N Carolina State Univ, Coll Vet Med, Dept Clin Sci, Raleigh, NC 27606 USA. N Carolina State Univ, Coll Vet Med, Dept Mol & Biomed Sci, Raleigh, NC 27606 USA. N Carolina State Univ, Ctr Marine Sci & Technol, Morehead City, NC 28557 USA. EC Trl, Anim Programs, Disneys Epcot Living Seas, Lake Buena Vista, FL 32830 USA. Galveston Lab, Natl Marine Fisheries Serv, Natl Ocean & Atmospher Adm, Galveston, TX 77551 USA. Beaufort Lab, Natl Ocaenog & Atmopher Adm, Natl Marine Fisheries Serv, Beaufort, NC 28516 USA. RP Harms, CA (reprint author), N Carolina State Univ, Environm Consortium, 4700 Hillsborough St, Raleigh, NC 27606 USA. RI Hohn, Aleta/G-2888-2011 OI Hohn, Aleta/0000-0002-9992-7062 NR 33 TC 6 Z9 6 U1 0 U2 2 PU AMER ASSOC ZOO VETERINARIANS PI MEDIA PA 6 NORTH PENNELL ROAD, MEDIA, PA 19063 USA SN 1042-7260 J9 J ZOO WILDLIFE MED JI J. Zoo Wildl. Med. PD DEC PY 2004 VL 35 IS 4 BP 477 EP 488 DI 10.1638/03-083 PG 12 WC Veterinary Sciences SC Veterinary Sciences GA 889NR UT WOS:000226450200006 PM 15732588 ER PT J AU Kestner, R Witebsky, C Clampin, M Lyon, RG Woodruff, R AF Kestner, R Witebsky, C Clampin, M Lyon, RG Woodruff, R TI Irregularly figured plates correct wavefront errors SO LASER FOCUS WORLD LA English DT Article AB Aspheric plates for placement in telescopes can be figured to correct wavefront errors at mid-spatial-frequency ranges up to 50 cycles/aperture and beyond. C1 ASML Opt Wilton, Wilton, CT 06897 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Lockheed Martin Civil Space, Denver, CO 80201 USA. RP Kestner, R (reprint author), ASML Opt Wilton, 77 Danbury Rd, Wilton, CT 06897 USA. RI Clampin, mark/D-2738-2012 NR 3 TC 0 Z9 0 U1 0 U2 0 PU PENNWELL PUBL CO PI NASHUA PA 98 SPIT BROOK RD, NASHUA, NH 03062-2801 USA SN 0740-2511 J9 LASER FOCUS WORLD JI Laser Focus World PD DEC PY 2004 VL 40 IS 12 BP 91 EP 93 PG 3 WC Optics SC Optics GA 883WJ UT WOS:000226046100031 ER PT J AU DiGiacomo, PM Washburn, L Holt, B Jones, BH AF DiGiacomo, PM Washburn, L Holt, B Jones, BH TI Coastal pollution-hazards in southern California observed by SAR imagery: stormwater plumes, wastewater plumes, and natural hydrocarbon seeps SO MARINE POLLUTION BULLETIN LA English DT Article DE hydrocarbon seeps; runoff; slicks; Southern California; synthetic aperture radar; wastewater; plumes ID EXTRACTABLE ORGANIC-MATTER; SANTA-BARBARA CHANNEL; COAL-OIL-POINT; OCEAN SURFACE; MOLECULAR CHARACTERIZATION; CHARACTERISTIC PATTERNS; MUNICIPAL WASTEWATERS; SPILL DETECTION; CIRCULATION; RADAR AB Stormwater runoff plumes, municipal wastewater plumes, and natural hydrocarbon seeps are important pollution hazards for the heavily populated Southern California Bight (SCB). Due to their small size, dynamic and episodic nature, these hazards are difficult to sample adequately using traditional in situ oceanographic methods. Complex coastal circulation and persistent cloud cover can further complicate detection and monitoring of these hazards. We use imagery from space-borne synthetic aperture radar (SAR), complemented by field measurements, to examine these hazards in the SCB. The hazards are detectable in SAR imagery because they deposit surfactants on the sea surface, smoothing capillary and small gravity waves to produce areas of reduced. backscatter compared with the surrounding ocean. We suggest that high-resolution SAR, which obtains useful data regardless of darkness or cloud cover, could be an important observational tool for assessment and monitoring of coastal marine pollution hazards in the SCB and other urbanized coastal regions. (C) 2004 Elsevier Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Santa Barbara, Dept Geog, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. Univ So Calif, Hancock Inst Marine Studies, Los Angeles, CA 90089 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM pmd@pacific.jpl.nasa.gov RI DiGiacomo, Paul/F-5584-2010 OI DiGiacomo, Paul/0000-0003-4550-1899 NR 62 TC 40 Z9 41 U1 0 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0025-326X EI 1879-3363 J9 MAR POLLUT BULL JI Mar. Pollut. Bull. PD DEC PY 2004 VL 49 IS 11-12 BP 1013 EP 1024 DI 10.1016/j.marpolbul.2004.07.016 PG 12 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 882GH UT WOS:000225926700028 PM 15556188 ER PT J AU Abdul-Aziz, A Ghosn, LJ Baaklini, GY Rauser, RW Zima, JD AF Abdul-Aziz, A Ghosn, LJ Baaklini, GY Rauser, RW Zima, JD TI A combined NDT/fatigue test and three dimensional image processing study of a SiC/SiC composite system SO MATERIALS EVALUATION LA English DT Article AB Nondestructive testing (NDT) is a critical technology for improving the quality of a component in a cost conscious production environment. NDT detects variations in a material or a component without altering or damaging the test piece. Using these techniques to improve the production process requires characterization of the discontinuities and their influence on the component performance. This task depends on the material properties and on the complexity of the component geometry. Hence, NDT is applied to study the structural durability of ceramic matrix composite materials used in gas turbine engine applications. These materials are composed of coated two dimensional woven high strength fiber toes and melt infiltrated ceramic matrices. Matrix voids are common discontinuities generated during the melt infiltration process. The effects of these matrix porosities are usually associated with a reduction in the initial overall composite stiffness and an increase in the thermal conductivity of the component. Furthermore, since the role of the matrix as well as the coating is to protect the fibers from the harsh engine environments, the current design approach is to limit the design stress level of ceramic matrix composite components to always be below the first matrix cracking stress. In this study, the effect of matrix porosity on the matrix cracking stress is tested using a combination of fatigue tensile testing, NDT and three dimensional image processing. Computed tomography is utilized as the NDT technique to characterize the initial matrix porosity's locations and sizes in various ceramic matrix composite test specimens. The three dimensional volume rendering approach is exercised to construct the three dimensional volume of the specimen based on the geometric modeling of the specimen's computed tomography results using image analysis and geometric modeling software. The same scanned specimens are then fatigue tested to various maximum loads and temperatures to depict the matrix cracking locations in relation to the initial damage. The specimens are then rescanned and checked for further discontinuities and obvious changes in the damage state. Finally, rendered volumes of the gage region of the specimen are generated and observed to check damage progression with increasing cycles. Observations and critical findings related to this material are reported. C1 Cleveland State Univ, Dept Civil & Environm Engn, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Ohio Aerosp Inst, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Opt Instrumentat Technol Branch, Cleveland, OH 44135 USA. RP Abdul-Aziz, A (reprint author), Cleveland State Univ, Dept Civil & Environm Engn, NASA, Glenn Res Ctr, 21000 Brookpk Rd MS 6-1, Cleveland, OH 44135 USA. EM smaziz@grc.nasa.gov; louis.j.ghosn@grc.nasa.gov; george.y.baaklini@grc.nasa.gov; richard.w.rauser@grc.nasa.gov; john.d.zima@grc.nasa.gov NR 6 TC 0 Z9 0 U1 0 U2 1 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 DEC PY 2004 VL 62 IS 12 BP 1222 EP 1226 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA 879FV UT WOS:000225702700006 ER PT J AU Nuth, JA Hill, HGM AF Nuth, JA Hill, HGM TI Planetary accretion, oxygen isotopes, and the central limit theorem SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID SOLAR NEBULA; INTRAMOLECULAR THEORY; ORDINARY CHONDRITES; GRAINS; METEORITES; EVOLUTION; COMETS; FRACTIONATION; HETEROGENEITY; CONSTRAINTS AB The accumulation of presolar dust into increasingly larger aggregates such as calcium-aluminum-rich inclusions (CAIs) and chondrules, asteroids, and planets should result in a drastic reduction in the numerical spread in oxygen isotopic composition between bodies of similar size, in accord with the central limit theorem. Observed variations in oxygen isotopic composition are many orders of magnitude larger than would be predicted by a simple, random accumulation model that begins in a well-mixed nebula, no matter what size objects are used as the beginning or end points of the calculation. This discrepancy implies either that some as yet unspecified but relatively long-lived process acted on the solids in the solar nebula to increase the spread in oxygen isotopic composition during each and every stage of accumulation, or that the nebula was heterogeneous (at least in oxygen) and maintained this heterogeneity throughout most of its nebular history. Depending on its origin, large-scale nebular heterogeneity could have significant consequences for many areas of cosmochemistry, including the application of well-known isotopic systems to the dating of nebular events and the prediction of bulk compositions of planetary bodies on the basis of a uniform cosmic abundance. The evidence supports a scenario wherein the oxygen isotopic composition of nebular solids becomes progressively depleted in (16)O With time due to chemical processing within the nebula, rather than a scenario where (16)O-rich dust and other materials are injected into the nebula, possibly causing its initial collapse. C1 NASA, Goddard Space Flight Ctr, Astrochem Branch, Greenbelt, MD 20771 USA. Int Space Univ, F-67400 Illkirch Graffenstaden, France. RP Nuth, JA (reprint author), NASA, Goddard Space Flight Ctr, Astrochem Branch, Code 691, Greenbelt, MD 20771 USA. EM Joseph.A.Nuth@nasa.gov RI Nuth, Joseph/E-7085-2012 NR 38 TC 4 Z9 4 U1 0 U2 0 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 DEC PY 2004 VL 39 IS 12 BP 1957 EP 1965 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 901GE UT WOS:000227270200005 ER PT J AU Fischer, CF Rubin, RH AF Fischer, CF Rubin, RH TI Breit-Pauli energy levels, transition probabilities and lifetimes for 3d(5) levels in FeIV of astrophysical interest SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE atomic data; atomic processes ID ORION NEBULA; IRON PROJECT; ATOMIC DATA; IV; EXCITATION; LINES AB Energy levels, lifetimes and transition probabilities for transitions between computed levels of 3d(5) of Fe IV are reported. The E2 and M1 transition probabilities are compared with earlier theoretical results, often only the values published by Garstang in 1958. From the available astronomical observations of optical emission lines arising from the same level, a few direct tests are now possible and they show consistency with the theoretical calculations. C1 Vanderbilt Univ, Dept Comp Sci, Nashville, TN 37232 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Orion Enterprises, Moffett Field, CA 94035 USA. RP Fischer, CF (reprint author), Vanderbilt Univ, Dept Comp Sci, Box 1679B, Nashville, TN 37232 USA. EM Charlotte.F.Fischer@Vanderbilt.Edu; rubin@cygnus.arc.nasa.gov NR 14 TC 10 Z9 10 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 DEC 1 PY 2004 VL 355 IS 2 BP 461 EP 474 DI 10.1111/j.1365-2966.2004.08332.x PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 873FJ UT WOS:000225265000015 ER PT J AU Ngo, Q Cruden, BA Cassell, AM Sims, G Meyyappan, M Li, J Yang, CY AF Ngo, Q Cruden, BA Cassell, AM Sims, G Meyyappan, M Li, J Yang, CY TI Thermal interface properties of Cu-filled vertically aligned carbon nanofiber arrays SO NANO LETTERS LA English DT Article ID NANOTUBES AB Nanoengineered materials have emerged as efficient thermal interface materials in a variety of thermal management applications. For example, integrated circuits (IC) are subject to tight thermal budgets to maintain acceptable reliability standards, This letter presents thermal contact resistance measurement results and analyses for copper gap-filled carbon nanofiber-copper composite arrays. Experimental results demonstrate the efficient interfacial thermal conduction of these structures. Using copper as a gap-fill material for improving lateral heat spreading and mechanical stability is discussed. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Santa Clara Univ, Ctr Nanostruct, Santa Clara, CA 95050 USA. RP Li, J (reprint author), NASA, Ames Res Ctr, 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 17 TC 132 Z9 136 U1 5 U2 49 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 DEC PY 2004 VL 4 IS 12 BP 2403 EP 2407 DI 10.1021/nl048506t PG 5 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 878XS UT WOS:000225681300018 ER PT J AU Bicknell, GV Jones, DL Lister, M AF Bicknell, GV Jones, DL Lister, M TI Relativistic jets SO NEW ASTRONOMY REVIEWS LA English DT Article ID ACTIVE GALACTIC NUCLEI; RADIO JETS; BLACK-HOLES; GALAXY; QUASARS; MARKARIAN-501; OBJECTS; FLOWS; VLBI AB Despite substantial observational and theoretical progress over many years, numerous key questions surrounding the topic of relativistic jets remain to be answered. In particular we still do not know how they are ejected from the supermassive black holes that are implicated in their production and we do not know how the ejection of matter at relativistic speeds is related to the properties of the parent galaxy. We are also just beginning to appreciate the role that relativistic jets play in the feedback loop between black holes and forming galaxies. The SKA will have a major impact in this field. The ability to image low luminosity sources and to map out the details of the interaction between jets and their environments will assist in understanding much of the physics of relativistic jets that is currently inaccessible. (C) 2004 Elsevier B.V. All rights reserved. C1 Australian Natl Univ, Mt Stromlo Observ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. RP Bicknell, GV (reprint author), Australian Natl Univ, Mt Stromlo Observ, Res Sch Astron & Astrophys, Cotter Rd, Weston, ACT 2611, Australia. EM geoff@mso.anu.edu.au NR 31 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD DEC PY 2004 VL 48 IS 11-12 BP 1151 EP 1155 DI 10.1016/j.newar.2004.09.005 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 885HD UT WOS:000226146800017 ER PT J AU Morganti, R Greenhill, LJ Peck, AB Jones, DL Henkel, C AF Morganti, R Greenhill, LJ Peck, AB Jones, DL Henkel, C TI Disks, tori, and cocoons: emission and absorption diagnostics of AGN environments SO NEW ASTRONOMY REVIEWS LA English DT Article ID ACTIVE GALACTIC NUCLEI; WATER-VAPOR MEGAMASER; H2O MASER EMISSION; PARSEC-SCALE JETS; ACCRETION DISK; NEUTRAL HYDROGEN; HI ABSORPTION; RADIO-SOURCES; BLACK-HOLES; GALAXY AB One of the most important problems in the study of active galaxies is understanding the detailed geometry, physics, and evolution of the central engines and their environments. The leading models involve an accretion disk and torus structure around a central dense object, thought to be a supermassive black hole. Gas found in the environment of active galactic nuclei (AGN) is associated with different structures: molecular accretion disks, larger scale atomic tori, ionized and neutral "cocoons" in which the nuclear regions can be embedded. All of them can be studied at radio wavelengths by various means. Here, we summarize the work that has been done to date in the radio band to characterize these structures. Much has been learned about the central few parsecs of AGN in the last few decades with contemporary instruments but the picture remains incomplete. In order to be able to define a more accurate model of this region, significant advances in sensitivity, spectral and angular resolution, and bandpass stability are required. The necessary advances will only be provided by the Square Kilometer Array and we discuss the possibilities that these dramatic improvements will open for the study of the gas in the central region of AGN. (C) 2004 Elsevier B.V. All rights reserved. C1 Netherlands Fdn Res Astron, NL-7900 AA Dwingeloo, Netherlands. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Smithsonian Ctr Astrophys, SMA Project, Hilo, HI 96720 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. MPIfR, D-53121 Bonn, Germany. RP Morganti, R (reprint author), Netherlands Fdn Res Astron, Postbus 2, NL-7900 AA Dwingeloo, Netherlands. EM morganti@astron.nl; greenhill@cfa.harvard.edu; apeck@cfa.harvard.edu; dj@sgra.jpl.nasa.gov; p220hen@m-pifr-bonn.mpg.de NR 61 TC 15 Z9 17 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD DEC PY 2004 VL 48 IS 11-12 BP 1195 EP 1209 DI 10.1016/j.newar.2004.09.022 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 885HD UT WOS:000226146800021 ER PT J AU Jones, DL AF Jones, DL TI Spacecraft tracking with the SKA SO NEW ASTRONOMY REVIEWS LA English DT Article AB The possibility of using the SKA for occasional support of scientific space missions should be considered, along with all other science goals, in the design of the array. The benefits of higher data rates from distant spacecraft during high priority, short duration mission phases can be dramatic, while the technical requirements on the SKA to allow this capability are very few. The most fundamental requirement is coverage of the primary downlink frequencies for deep space missions. Additional benefits can result from real-time high precision angular position measurements of spacecraft. Such measurements allow spacecraft navigation with reduced errors and reduced risk, but require at least some long (thousands of km) baselines. (C) 2004 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Jones, DL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA USA. EM dj@sgra.jpl.nasa.gov NR 7 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 1387-6473 J9 NEW ASTRON REV JI New Astron. Rev. PD DEC PY 2004 VL 48 IS 11-12 BP 1537 EP 1542 DI 10.1016/j.newar.2004.09.021 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 885HD UT WOS:000226146800047 ER PT J AU Lorenzo, CF Hartley, TT AF Lorenzo, CF Hartley, TT TI Fractional trigonometry and the spiral functions SO NONLINEAR DYNAMICS LA English DT Article DE fractional calculus; fractional differential equations; fractional Euler equation; fractional semi-Euler equation; fractional trigonometry; fractional trigonometric functions; R-function; spiral functions AB This paper develops two related fractional trigonometries based on the multi-valued fractional generalization of the exponential function, the R-function. The trigonometries contain the traditional trigonometric functions as proper subsets. Also developed are relationships between the R-function and the new fractional trigonometric functions. Laplace transforms are derived for the new functions and are used to generate solution sets for various classes of fractional differential equations. Because of the fractional character of the R-function, several new trigonometric functions are required to augment the traditional sine, cosine, etc. functions. Fractional generalizations of the Euler equation are derived. As a result of the fractional trigonometry a new set of phase plane functions, the Spiral functions, that contain the circular functions as a subset, is identified. These Spiral functions display many new symmetries. C1 NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Akron, Dept Elect & Comp Engn, Akron, OH 44325 USA. RP Lorenzo, CF (reprint author), NASA, John H Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM Carl.F.Lorenzo@grc.nasa.gov NR 11 TC 23 Z9 23 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0924-090X J9 NONLINEAR DYNAM JI Nonlinear Dyn. PD DEC PY 2004 VL 38 IS 1-4 BP 23 EP 60 DI 10.1007/s11071-004-3745-9 PG 38 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 892RK UT WOS:000226667500003 ER PT J AU Hartley, TT Lorenz, CF AF Hartley, TT Lorenz, CF TI A frequency-domain approach to optimal fractional-order damping SO NONLINEAR DYNAMICS LA English DT Article DE fractional-order resonances; fractional-order systems; optimal damping AB In this paper, we will consider the single term optimal fractional-order damper for an otherwise undamped oscillator. First, we will find the single term damper that minimizes the time domain integral of the squared step error (2-norm) and the integral of the time-weighted squared error (Hilbert-Schmidt-Hankel norm). Next we will consider a more intuitive frequency domain approach that insures the maximally flat magnitude response. Time and frequency domain plots are given for comparison with the integer-order solutions. Further improvements in performance are shown to be possible using multiple active fractional-order dampers. C1 Univ Akron, Dept Elect & Comp Engn, Akron, OH 44325 USA. NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. RP Hartley, TT (reprint author), Univ Akron, Dept Elect & Comp Engn, Akron, OH 44325 USA. EM tomhartley@aol.com NR 12 TC 13 Z9 16 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0924-090X J9 NONLINEAR DYNAM JI Nonlinear Dyn. PD DEC PY 2004 VL 38 IS 1-4 BP 69 EP 84 DI 10.1007/s11071-004-3747-7 PG 16 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 892RK UT WOS:000226667500005 ER PT J AU Nedialkov, NS Kreinovich, V Starks, SA AF Nedialkov, NS Kreinovich, V Starks, SA TI Interval arithmetic, affine arithmetic, Taylor series methods: why, what next? SO NUMERICAL ALGORITHMS LA English DT Article; Proceedings Paper CT International Symposium on Scientific Computing, Computer Arithmetic and Validated Numerics CY SEP 23-27, 2002 CL Paris, FRANCE SP GAMM, IMACS DE affine arithmetic; Taylor methods; Hermite-Obreschkoff method; optimal selection of approximating family AB In interval computations, the range of each intermediate result r is described by an interval r. To decrease excess interval width, we can keep some information on how r depends on the input x=(x(1),..., x(n)). There are several successful methods of approximating this dependence; in these methods, the dependence is approximated by linear functions (affine arithmetic) or by general polynomials (Taylor series methods). Why linear functions and polynomials? What other classes can we try? These questions are answered in this paper. C1 McMaster Univ, Dept Comp & Software, Hamilton, ON L8S 4L7, Canada. Univ Texas, NASA, PACES, El Paso, TX 79968 USA. RP Nedialkov, NS (reprint author), McMaster Univ, Dept Comp & Software, Hamilton, ON L8S 4L7, Canada. EM nedialk@mcmaster.ca; vladik@cs.utep.edu; sstarks@utep.edu NR 26 TC 22 Z9 22 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1017-1398 J9 NUMER ALGORITHMS JI Numer. Algorithms PD DEC PY 2004 VL 37 IS 1-4 BP 325 EP 336 DI 10.1023/B:NUMA.0000049478.42605.cf PG 12 WC Mathematics, Applied SC Mathematics GA 874BF UT WOS:000225325200031 ER PT J AU Hara, H Walsh, BM Barnes, NP AF Hara, H Walsh, BM Barnes, NP TI Tunability of a 946-nm Nd : YAG microchip laser versus output mirror reflectivity and crystal length SO OPTICAL ENGINEERING LA English DT Article DE diode-pumped lasers; laser materials; tunable lasers AB We measured the tunability of a Nd:YAG, 946-nm microchip laser as the function of the laser crystal length and the reflectivity of the output mirror. A decrease in the tunable range is observed with the decrease in the reflectivity of the output mirror and the crystal length. The center oscillation wavelength is estimated to be similar to946.1 nm. The oscillation wavelength varies between similar to945.8 and similar to946.4 nm for our experiments. (C) 2004 Society of Photo-Optical Instrumentation Engineers. C1 Leadintex Int Inc, Chuo Ku, Tokyo 1030011, Japan. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Hara, H (reprint author), Leadintex Int Inc, Chuo Ku, 1-3 Nihonbashi Ohdenmacho, Tokyo 1030011, Japan. NR 5 TC 2 Z9 2 U1 0 U2 0 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD DEC PY 2004 VL 43 IS 12 BP 3026 EP 3028 DI 10.1117/1.1814491 PG 3 WC Optics SC Optics GA 884GA UT WOS:000226071600029 ER PT J AU Ertem, G AF Ertem, G TI Montmorillonite, oligonucleotides, RNA and origin of life SO ORIGINS OF LIFE AND EVOLUTION OF THE BIOSPHERE LA English DT Article DE HPLC; mineral catalysis; montmorillonite; oligonucleotides; origin of life; regioselectivity; RNA; self-condensation; template directed synthesis ID TEMPLATE-DIRECTED SYNTHESIS; PHOSPHODIESTER BOND FORMATION; OLIGOMERIZATION REACTIONS; PREBIOTIC SYNTHESIS; AQUEOUS-SOLUTION; 3,5-LINKED OLIGOADENYLATES; ACTIVATED MONONUCLEOTIDES; REGIOSELECTIVE FORMATION; HETEROGENEOUS TEMPLATES; NA+-MONTMORILLONITE AB Na-montmorillonite prepared from Volclay by the titration method facilitates the self-condensation of ImpA, the 5'-phosphorimidazolide derivative of adenosine. As was shown by AE-HPLC analysis and selective enzymatic hydrolysis of products, oligo(A)s formed in this reaction are 10 monomer units long and contain 67% 3',5'-phosphodiester bonds (Ferris and Ertem, 1992a). Under the same reaction conditions, 5'-phosphorimidazolide derivatives of cytidine, uridine and guanosine also undergo self-condensation producing oligomers containing up to 12-14 monomer units for oligo(C) s to 6 monomer units for oligo(G) s. In oligo(C) s and oligo(U) s, 75-80% of the monomers are linked by 2',5'-phosphodiester bonds. Hexamer and higher oligomers isolated from synthetic oligo(C) s formed by montmorillonite catalysis, which contain both 3',5'- and 2',5'- linkages, serve as catalysts for the non-enzymatic template directed synthesis of oligo(G) s from activated monomer 2-MeImpG, guanosine 5'-phospho-2-methylimidazolide (Ertem and Ferris, 1996). Pentamer and higher oligomers containing exclusively 2',5'-linkages, which were isolated from the synthetic oligo(C) s, also serve as templates and produce oligo(G) s with both 2',5'- and 3',5'-phosphodiester bonds. Kinetic studies on montmorillonite catalyzed elongation rates of oligomers using the computer program SIMFIT demonstrated that the rate constants for the formation of oligo(A) s increased in the order of 2-mer<3-mer<4-mer...<7-mer (Kawamura and Ferris, 1994). A decameric primer, dA(pdA)(8)pA bound to montmorillonite was elongated to contain up to 50 monomer units by daily addition of activated monomer ImpA to the reaction mixture ( Ferris, Hill and Orgel, 1996). Analysis of dimer fractions formed in the montmorillonite catalyzed reaction of binary and quaternary mixtures of ImpA, ImpC, 2-MeImpG and ImpU suggested that only a limited number of oligomers could have formed on the primitive Earth rather than equal amounts of all possible isomers (Ertem and Ferris, 2000). Formation of phosphodiester bonds between mononucleotides by montmorillonite catalysis is a fascinating discovery, and a significant step forward in efforts to find out how the first RNA-like oligomers might have formed in the course of chemical evolution. However, as has been pointed out in several publications, these systems should be regarded as models rather than a literal representation of prebiotic chemistry (Orgel, 1998; Joyce and Orgel, 1999; Schwartz, 1999). C1 Georgetown Univ, Lombardi Canc Ctr, Washington, DC 20057 USA. RP Ertem, G (reprint author), NASA, Goddard Space Flight Ctr, Code 691, Greenbelt, MD 20771 USA. EM gertem@lepvax.gsfc.nasa.gov NR 68 TC 41 Z9 43 U1 2 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 DEC PY 2004 VL 34 IS 6 BP 549 EP 570 DI 10.1023/B:ORIG.0000043130.49790.a7 PG 22 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 857PI UT WOS:000224130400002 PM 15570708 ER PT J AU Kral, TA Bekkum, CR McKay, CP AF Kral, TA Bekkum, CR McKay, CP TI Growth of methanogens on a mars soil simulant SO ORIGINS OF LIFE AND EVOLUTION OF THE BIOSPHERE LA English DT Article DE JSC Mars-1; Mars; Mars soil simulant; methanogen ID NITROGEN-FIXATION; ECOSYSTEMS; TEPHRA; LIFE AB Currently, the surface of Mars is probably too cold, too dry, and too oxidizing for life, as we know it, to exist. But the subsurface is another matter. Life forms that might exist below the surface could not obtain their energy from photosynthesis, but rather they would have to utilize chemical energy. Methanogens are one type of microorganism that might be able to survive below the surface of Mars. A potential habitat for existence of methanogens on Mars might be a geothermal source of hydrogen, possibly due to volcanic or hydrothermal activity, or the reaction of basalt and anaerobic water, carbon dioxide, which is abundant in the martian atmosphere, and of course, subsurface liquid water. We report here that certain methanogens can grow on a Mars soil simulant when supplied with carbon dioxide, molecular hydrogen, and varying amounts of water. C1 Univ Arkansas, Arkansas Oklahoma Ctr Space & Planetary Sci, Fayetteville, AR 72701 USA. Univ Arkansas, Dept Biol Sci, Fayetteville, AR 72701 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Kral, TA (reprint author), Univ Arkansas, Arkansas Oklahoma Ctr Space & Planetary Sci, Fayetteville, AR 72701 USA. EM tkral@uark.edu NR 28 TC 38 Z9 41 U1 4 U2 13 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 DEC PY 2004 VL 34 IS 6 BP 615 EP 626 DI 10.1023/B:ORIG.0000043129.68196.5f PG 12 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 857PI UT WOS:000224130400005 PM 15570711 ER PT J AU Shimasaki, M Zima, HP AF Shimasaki, M Zima, HP TI The Earth Simulator SO PARALLEL COMPUTING LA English DT Editorial Material C1 Kyoto Univ, Dept Elect Engn, Kyoto 6158510, Japan. JPL, Pasadena, CA USA. Univ Vienna, CALTECH, Vienna, Austria. RP Shimasaki, M (reprint author), Kyoto Univ, Dept Elect Engn, Kyoto 6158510, Japan. EM simasaki@kuee.kyoto-u.ac.jp; zima@jpl.nasa.gov NR 4 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8191 J9 PARALLEL COMPUT JI Parallel Comput. PD DEC PY 2004 VL 30 IS 12 BP 1277 EP 1278 DI 10.1016/j.parco.2004.09.002 PG 2 WC Computer Science, Theory & Methods SC Computer Science GA 879MO UT WOS:000225722100001 ER PT J AU Hodgson, ME Li, XG Cheng, Y AF Hodgson, ME Li, XG Cheng, Y TI A parameterization model for transportation feature extraction SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article AB This article presents one solution to the parameterization problem for automated road feature extraction models. Using a line-length buffer approach, a measure of agreement between extracted road features and reference road features is defined. An automated approach for deriving this agreement index is presented and implemented as a parameterization model. Coupling the implemented parameterization model with an existing transportation feature extraction model is demonstrated. Although the solution was designed for a road feature extraction model (FEM), the conceptual design could be applied to other linear FEMs, such as models for streams, fault lines, and isolines. C1 Univ S Carolina, Dept Geog, Columbia, SC 29208 USA. Univ Kansas, Dept Geog, Lawrence, KS 66045 USA. Jet Propuls Lab, Machine Vis Grp, Pasadena, CA 91109 USA. RP Hodgson, ME (reprint author), Univ S Carolina, Dept Geog, Columbia, SC 29208 USA. EM hodgsonm@sc.edu NR 6 TC 9 Z9 9 U1 2 U2 3 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 USA SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD DEC PY 2004 VL 70 IS 12 BP 1399 EP 1404 PG 6 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 877NP UT WOS:000225577600012 ER PT J AU Gao, CJ Zhang, SN AF Gao, CJ Zhang, SN TI Dilaton black holes in the de Sitter or anti-de Sitter universe SO PHYSICAL REVIEW D LA English DT Article ID STRING THEORY; GRAVITY THEORIES; FIELD-THEORIES; SPACETIMES AB Poletti and Wiltshire have shown that, with the exception of a pure cosmological constant, the solution of a dilaton black hole in the background of de Sitter or anti-de Sitter universe, does not exist in the presence of one Liouville-type dilaton potential. In this work we obtain the dilaton black-hole solutions in the background of the de Sitter or anti-de Sitter universe, with the combination of three Liouville-type dilaton potentials. C1 Tsinghua Univ, Dept Phys, Beijing 100084, Peoples R China. Tsinghua Univ, Ctr Astrophys, Beijing 100084, Peoples R China. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Space Sci Lab, Huntsville, AL 35812 USA. Chinese Acad Sci, Inst High Energy Phys, Key Lab Particle Astrophys, Beijing 100039, Peoples R China. RP Tsinghua Univ, Dept Phys, Beijing 100084, Peoples R China. EM gaocj@mail.tsinghua.edu.cn; zhangsn@mail.tsinghua.edu.cn NR 30 TC 35 Z9 35 U1 1 U2 2 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 DEC PY 2004 VL 70 IS 12 AR 124019 DI 10.1103/PhysRevD.70.124019 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 883ZQ UT WOS:000226054800065 ER PT J AU Imbiriba, B Baker, J Choi, DI Centrella, J Fiske, DR Brown, JD van Meter, JR Olson, K AF Imbiriba, B Baker, J Choi, DI Centrella, J Fiske, DR Brown, JD van Meter, JR Olson, K TI Evolving a puncture black hole with fixed mesh refinement SO PHYSICAL REVIEW D LA English DT Article ID 3D NUMERICAL RELATIVITY; ADAPTIVE MESH; INITIAL DATA; COLLISIONS; EQUATIONS AB We present an algorithm for treating mesh refinement interfaces in numerical relativity. We discuss the behavior of the solution near such interfaces located in the strong-field regions of dynamical black hole spacetimes, with particular attention to the convergence properties of the simulations. In our applications of this technique to the evolution of puncture initial data with vanishing shift, we demonstrate that it is possible to simultaneously maintain second order convergence near the puncture and extend the outer boundary beyond 100M, thereby approaching the asymptotically flat region in which boundary condition problems are less difficult and wave extraction is meaningful. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Phys, College Pk, MD 20740 USA. Univ Space Res Assoc, Lanham, MD 20706 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Earth & Space Data Comp Div, Greenbelt, MD 20771 USA. RP Imbiriba, B (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RI van meter, james/E-7893-2011 NR 32 TC 42 Z9 42 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 DEC PY 2004 VL 70 IS 12 AR 124025 DI 10.1103/PhysRevD.70.124025 PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 883ZQ UT WOS:000226054800071 ER PT J AU Zhong, F Barmatz, M AF Zhong, F Barmatz, M TI Comparison of theoretical models of crossover behavior near the He-3 liquid-vapor critical point SO PHYSICAL REVIEW E LA English DT Article ID NONASYMPTOTIC CRITICAL-BEHAVIOR; 3 DIMENSIONS; MINIMAL RENORMALIZATION; EPSILON-EXPANSION; FIELD-THEORY; HEAT AB Parametric expressions, based on three different theoretical models, are used to calculate the isothermal susceptibility, specific heat, and order parameter along the critical isochore and coexistence curve from the asymptotic region to the crossover region. These models are (i) the minimal-subtraction renormalization scheme, (ii) the massive renormalization scheme within the phi(4) model, and (iii) the crossover parametric model based on the crossover Landau model. We fit these theories globally to experimental measurements of the isothermal susceptibility and specific heat along the critical isochore and coexistence curve, and to the coexistence curve of He-3 near its liquid-vapor critical point. All of the theories provide good agreement with the experimental measurements within the reduced temperature range \t\less than or equal to2x10(-2). The differences in the fits between the theories and the correlations between the adjustable model parameters are discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Zhong, F (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 22 TC 11 Z9 11 U1 0 U2 0 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 DEC PY 2004 VL 70 IS 6 AR 066105 DI 10.1103/PhysRevE.70.066105 PN 2 PG 9 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 887IM UT WOS:000226299200012 PM 15697432 ER PT J AU Hesse, M Kuznetsova, M Birn, J AF Hesse, M Kuznetsova, M Birn, J TI The role of electron heat flux in guide-field magnetic reconnection SO PHYSICS OF PLASMAS LA English DT Article ID COLLISIONLESS RECONNECTION; PARTICLE SIMULATIONS; PLASMA; CHALLENGE; MAGNETOPAUSE; SIGNATURES; REGION; HYBRID; FLOWS; LINE AB A combination of analytical theory and particle-in-cell simulations are employed in order to investigate the electron dynamics near and at the site of guide field magnetic reconnection. A detailed analysis of the contributions to the reconnection electric field shows that both bulk inertia and pressure-based quasiviscous processes are important for the electrons. Analytic scaling demonstrates that conventional approximations for the electron pressure tensor behavior in the dissipation region fail, and that heat flux contributions need to be accounted for. Based on the evolution equation of the heat flux three tensor, which is derived in this paper, an approximate form of the relevant heat flux contributions to the pressure tensor is developed, which reproduces the numerical modeling result reasonably well. Based on this approximation, it is possible to develop a scaling of the electron current layer in the central dissipation region. It is shown that the pressure tensor contributions become important at the scale length defined by the electron Larmor radius in the guide magnetic field. (C) 2004 American Institute of Physics. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hesse, M (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Hesse, Michael/D-2031-2012; Kuznetsova, Maria/F-6840-2012 NR 26 TC 56 Z9 56 U1 2 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 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD DEC PY 2004 VL 11 IS 12 BP 5387 EP 5397 DI 10.1063/1.1795991 PG 11 WC Physics, Fluids & Plasmas SC Physics GA 875VM UT WOS:000225450200004 ER PT J AU Gopalswamy, N AF Gopalswamy, N TI Recent advances in the long-wavelength radio physics of the Sun SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT EGS-AGU-EUG Joint Meeting CY APR 07-11, 2003 CL Nice, FRANCE SP EGS, AGU, EUG DE solar radio bursts; coronal mass ejections; flares; coronal shocks; interplanetary shocks; CME interaction ID CORONAL MASS EJECTIONS; SOLAR CORONA; II BURSTS; INTERPLANETARY SHOCKS; WIND SPACECRAFT; STORM RADIATION; MAGNETIC-FLUX; NEAR-SUN; EVENT; WAVES AB Solar radio bursts at long wavelengths provide information on solar disturbances such as coronal mass ejections (CMEs) and shocks at the moment of their departure from the Sun. The radio bursts also provide information on the physical properties (density, temperature and magnetic field) of the medium that supports the propagation of the disturbances with a valuable cross-check from direct imaging of the quiet outer corona. The primary objective of this paper is to review some of the past results and highlight recent results obtained from long-wavelength observations. In particular, the discussion will focus on radio phenomena occurring in the outer corona and beyond in relation to those observed in white light. Radio emission from nonthermal electrons confined to closed and open magnetic structures and in large-scale shock fronts will be discussed with particular emphasis on its relevance to solar eruptions. Solar cycle variation of the occurrence rate of shock-related radio bursts will be discussed in comparison with that of interplanetary shocks and solar proton events. Finally, case studies describing the newly-discovered radio signatures of interacting CMEs will be presented. Published by Elsevier Ltd. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Gopalswamy, N (reprint author), NASA, Goddard Space Flight Ctr, Bldg 26,Room G-1,Mailcode 682-3, Greenbelt, MD 20771 USA. EM gopals@fugee.gsfc.nasa.gov RI Gopalswamy, Nat/D-3659-2012 NR 71 TC 22 Z9 22 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2004 VL 52 IS 15 BP 1399 EP 1413 DI 10.1016/j.pss.2004.09.016 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 880RU UT WOS:000225807700008 ER PT J AU Zarka, P Farrell, WM Kaiser, ML Blanc, E Kurth, WS AF Zarka, P Farrell, WM Kaiser, ML Blanc, E Kurth, WS TI Study of solar system planetary lightning with LOFAR SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT Joint Assembly of the EGS/AGU/EUG CY APR 06-11, 2003 CL Nice, FRANCE SP EGS, AGU, EUG DE lightning; radio emission; radio astronomy; LOFAR; solar system; planetology ID SATURN ELECTROSTATIC DISCHARGES; MARTIAN DUST STORMS; RED SPRITES; RADIO; RADIATION; VENUS; IONOSPHERE; ATMOSPHERE; WHISTLERS; VOYAGER-1 AB Radio signatures of lightning discharges have been detected by the Voyager spacecraft near Saturn and Uranus up to 40 MHz. Corresponding flux densities at the distance of the Earth are up to 1000 Jansky (Jy) for Saturn ( greater than or equal to 1 event per minute above 50 Jy, with 30-300 ms duration) and up to a few tens of Jansky for Uranus. Low Frequency ARray LOFAR will allow us to detect and monitor the lightning activity at these two planets. Imaging will allow us to locate lightning sources on Saturn's disk (even if with moderate accuracy), which could then be correlated to optical imaging of clouds. Such observations could provide new information on electrification processes, atmospheric dynamics, composition, and geographical and seasonal variations, compared to the Earth. In addition, lightning may play a role in the atmospheric chemistry, through the production of non-equilibrium trace organic constituents potentially important for biological processes. LOFAR observations can also help us to assess the existence of lightning at Neptune (marginally detected by Voyager), at Venus (where their existence is very controversial), and at Mars (possibly resulting from dust cloud charging). At Jupiter, low-altitude ionospheric layers of meteoritic origin and/or intrinsically long discharge duration seem to prevent the emission and escape of high-frequency radio waves associated with lightning. LOFAR thus presents good possibilities for the detection and study of solar system planetary lightning; we also discuss its relevance to bring new information on Terrestrial lightning-related upper atmosphere transient phenomena (sprites, TIPPs...). Instrumental constraints are outlined. (C) 2004 Elsevier Ltd. All rights reserved. C1 CNRS, Observ Paris, LESIA, F-92195 Meudon, France. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. CEA, Bruyeres Le Chatel, France. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. RP Zarka, P (reprint author), CNRS, Observ Paris, LESIA, 5 Pl J Janssen, F-92195 Meudon, France. EM philippe.zarka@obspm.fr RI Farrell, William/I-4865-2013; Blanc, Elisabeth/D-3890-2009; OI Blanc, Elisabeth/0000-0002-1599-4736; Kurth, William/0000-0002-5471-6202 NR 68 TC 21 Z9 21 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2004 VL 52 IS 15 BP 1435 EP 1447 DI 10.1016/j.pss.2004.09.011 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 880RU UT WOS:000225807700011 ER PT J AU Farrell, WM Lazio, TJW Zarka, P Bastian, TJ Desch, MD Ryabov, BP AF Farrell, WM Lazio, TJW Zarka, P Bastian, TJ Desch, MD Ryabov, BP TI The radio search for extrasolar planets with LOFAR SO PLANETARY AND SPACE SCIENCE LA English DT Article; Proceedings Paper CT EGS-AGU-EUG Joint Meeting CY APR 07-11, 2003 CL Nice, FRANCE SP EGS, AGU, EUG ID AURORAL KILOMETRIC RADIATION; JUPITERS DECAMETRIC EMISSION; IO; RECONNECTION AB The Low Frequency Array (LOFAR) will come on line with unprecedented radio sensitivity and resolution between 10 and 240 MHz. Such a system will provide a factor of 10-30 improvement in sensitivity in the pursuit of the weak radio emission from extrasolar planets. To date, previous examinations of extrasolar planetary systems with the most advanced radio telescopes have yielded a negative result. However, the improvement in sensitivity by LOFAR over current systems will increase the likelihood of extrasolar planet detection in the radio. We apply radiometric models derived previously from the study of planets in our solar system to the known extrasolar planets, and demonstrate that approximately 3-5 of them should emit in the proper frequency range and with enough power to possibly become detectable at Earth with LOFAR. (C) 2004 Elsevier Ltd. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Res Lab, Washington, DC 20375 USA. Observ Paris, LESIA, F-92195 Meudon, France. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Inst Radio Astron, UA-310002 Kharkov, Ukraine. RP Farrell, WM (reprint author), NASA, Goddard Space Flight Ctr, Code 690, Greenbelt, MD 20771 USA. EM william.farrell@gsfc.nasa.gov RI Farrell, William/I-4865-2013 NR 43 TC 22 Z9 22 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD DEC PY 2004 VL 52 IS 15 BP 1469 EP 1478 DI 10.1016/j.pss.2004.09.018 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 880RU UT WOS:000225807700014 ER PT J AU Davarian, F Shambayati, S Slobin, S AF Davarian, F Shambayati, S Slobin, S TI Deep space Ka-band link management and Mars Reconnaissance Orbiter: Long-term weather statistics versus forecasting SO PROCEEDINGS OF THE IEEE LA English DT Article DE atmospheric noise temperature forecasting; deep space link management; Ka-band link design; satellite communications; weather effects on radio signals ID ATTENUATION AB During the last 40 years, deep space radio communication Systems have experienced a move toward shorter wavelengths. In the 1960s, a transition from L- to S-band occurred, which was followed by a transition from S- to X-band in the 1970s. Both these transitions provided deep space links with wider bandwidths and improved radio metrics capability. Now, in the 2000s, a new change is taking place: namely, a move to the Ka-band region of the radio frequency spectrum. Ka-band will soon replace X-band as the frequency of choice for deep space communications,. providing ample spectrum for the high data rate requirements of future missions. The-low-noise receivers of deep space networks have a great need for link management techniques that can mitigate weather effects. In this paper three approaches for managing Ka-band Earth-space links are investigated. The first approach uses aggregate annual statistics, the second one uses monthly statistics, and the third is based on the short-term forecasting of the local weather An example of weather forecasting for Ka-band link performance prediction is presented. Furthermore, spacecraft commanding schemes suitable for Ka-band link management are investigated. Theses schemes will be demonstrated using NASA's Mars Reconnaissance Orbiter spacecraft in the 2007-2008 period, and the demonstration findings will be reported in a future publication. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Davarian, F (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Davarian@jpl.nasa.gov; Shervin.Shambayati@jpl.nasa.gov; Stephen.D.Slobin@jpl.nasa.gov NR 11 TC 14 Z9 14 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9219 J9 P IEEE JI Proc. IEEE PD DEC PY 2004 VL 92 IS 12 BP 1879 EP 1894 DI 10.1109/JPROC.2004.837613 PG 16 WC Engineering, Electrical & Electronic SC Engineering GA 871XD UT WOS:000225169000003 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 II SO PURE AND APPLIED GEOPHYSICS LA English DT Editorial Material DE earthquake physics; numerical modeling; finite-element models; faults; theology; computational science C1 CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. Univ Queensland, Dept Earth Sci, ESSCC, QUAKES, Brisbane, Qld 4072, Australia. Univ Tokyo, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. China Acad Sci, Inst Mech, Lab Nonlinear Mech, Beijing 100080, Peoples R China. China Acad Sci, CSB, Ctr Anal & Predict, Beijing 100080, Peoples R China. RP Donnellan, A (reprint author), CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. EM donnellan@jpl.nasa.gov; morap@quakes.uq.edu.au; matsuura@eps.s.u-tokyo.ac.jp; xeyin@public.bta.net.en NR 0 TC 1 Z9 1 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 DEC PY 2004 VL 161 IS 11-12 BP 2119 EP 2122 DI 10.1007/s00024-004-2552-z PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 865WA UT WOS:000224733700001 ER PT J AU Glasscoe, MT Donnellan, A Kellogg, LH Lyzenga, GA AF Glasscoe, MT Donnellan, A Kellogg, LH Lyzenga, GA TI Evidence of strain partitioning between the Sierra Madre fault and the Los Angeles Basin, southern California from numerical models SO PURE AND APPLIED GEOPHYSICS LA English DT Article; Proceedings Paper CT 3rd ACES International Workshop CY MAY 05-10, 2002 CL Maui, HI DE crustal deformation; geodesy; numerical modeling; finite-element models; faults; rheology ID TRANSVERSE RANGES; DEFORMATION; BENEATH; MANTLE AB Geodetic data indicate that the northern Metropolitan Los Angeles region is shortening at a rate of 4.5-6.0 mm/yr between downtown Los Angeles and the San Gabriel Mountains. If we assume that all of the uplift of the San Gabriel Mountains is due to the major frontal fault system (the Sierra Madre fault) and use reported values for bedrock uplift, slip per event and recurrence intervals to determine the slip rate on the Sierra Madre fault, we obtain slip rates between 0.6-1.27 mm/yr. Using these slip rates, the horizontal shortening attributable to the Sierra Madre fault accounts for only similar to 33% of the observed shortening across the basin, leaving similar to 67% of the shortening to be accounted for elsewhere. Herein we present a suite of models that test possible shortening mechanisms to account for this strain deficit. The models incorporate a range of fault geometries and have a layered structure with variable vertical and horizontal rheologies. The models demonstrate how lower-crust rheology and the presence of a low rigidity, anelastically deforming sedimentary basin affects the dissipation of stress imposed on the viscous layers by elastic failure of the faults. We found that viscoelastic models with a single fault, vertically strong crust and a compliant sedimentary basin yield a horizontal velocity profile that best matches the geodetically observed velocity profile across the Los Angeles Basin. Our models also indicate that we are still not accounting for all of the observed deformation. Therefore, more complex models that include both laterally varying rheologies and frictional properties on faults must be considered. C1 Univ Calif Davis, Dept Geol, Davis, CA 95616 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Harvey Mudd Coll, Claremont, CA 91711 USA. RP Univ Calif Davis, Dept Geol, Davis, CA 95616 USA. EM glasscoe@jpl.nasa.gov; donnellan@jpl.nasa.gov; kellogg@geology.ucdavis.edu; lyzenga@hmc.edu RI Kellogg, Louise/J-2171-2012 OI Kellogg, Louise/0000-0001-5874-0472 NR 14 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER BASEL AG PI BASEL PA PICASSOPLATZ 4, BASEL, 4052, SWITZERLAND SN 0033-4553 EI 1420-9136 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD DEC PY 2004 VL 161 IS 11-12 BP 2343 EP 2357 DI 10.1007/s00024-004-2567-5 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 865WA UT WOS:000224733700016 ER PT J AU Kogut, A Wollack, E Fixsen, DJ Limon, M Mirel, P Levin, S Seiffert, M Lubin, PM AF Kogut, A Wollack, E Fixsen, DJ Limon, M Mirel, P Levin, S Seiffert, M Lubin, PM TI Design and calibration of a cryogenic blackbody calibrator at centimeter wavelengths SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID BACKGROUND-RADIATION AB We describe the design and calibration of an external cryogenic blackbody calibrator used for the first two flights of the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE) instrument. The calibrator consists of a microwave absorber weakly coupled to a superfluid liquid helium bath. Half-wave corrugations viewed 30degrees off axis reduce the return loss below -35 dB within a compact footprint. Ruthenium oxide resistive thermometers embedded within the absorber monitor the temperature across the face of the calibrator. The thermal calibration transfers the calibration of a reference thermometer to the flight thermometers using the flight thermometer readout system. The calibrator thermometry is stable in time over four years, with statistical uncertainty in the temperature calibration of order 2 mK near 2.7 K, limited primarily by thermal fluctuations in the liquid helium bath. Observations of the superfluid transition demonstrate that the absolute temperature scale is accurate within 0.3 mK. (C) 2004 American Institute of Physics. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, 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, Astron & Solar Phys Lab, SSAI Code 685, Greenbelt, MD 20771 USA. EM alan.j.kogut@nasa.gov 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 7 TC 10 Z9 10 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 DEC PY 2004 VL 75 IS 12 BP 5079 EP 5083 DI 10.1063/1.1821622 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 876FX UT WOS:000225483100001 ER PT J AU Rovati, L Bandera, A Donini, M Salvatori, G Pollonini, L AF Rovati, L Bandera, A Donini, M Salvatori, G Pollonini, L TI Design and performance of a wide-bandwidth and sensitive instrument for near-infrared spectroscopic measurements on human tissue SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID IN-VIVO; ABSORPTION; SCATTERING; OXYGENATION; QUANTIFICATION; COEFFICIENTS; REFLECTANCE; HEMOGLOBIN; SPECTRA; SIGNALS AB The article describes an instrument designed to perform in vivo near-infrared spectroscopic measurements on human tissues. The system integrates five continuous-wave laser diode sources emitting in the near-infrared spectral region and a low-noise detection system based on an avalanche photodiode. The optical probe is based on a compact, reliable, and low-cost fiber based system with four quantitative measuring points. The excellent sensitivity of the instrument allows one to perform quantitative assessments of the hemoglobin concentration exploiting precise absorption measurements close to the absorption peak of the water: 975 nm. Moreover, a good signal to noise ratio is obtained also at a high acquisition rate, allowing us to follow rapid changes in oxidative metabolism. The system bandwidth is selectable within the range 2.3-27 Hz, i.e., 20 channels (five chromatic and four spatial channels) can be acquired 27 times for each measuring second, whereas the system amplification can be set to measure optical density ranging from 3.5 to 8.5. A prototype version of the instrument has been realized and characterized. (C) 2004 American Institute of Physics. C1 Univ Modena & Reggio Emilia, Dept Informat Engn, I-41100 Modena, Italy. INFM, I-41100 Modena, Italy. NASA, Glenn Res Ctr, Ohio Aerosp Inst, Cleveland, OH USA. RP Rovati, L (reprint author), Univ Modena & Reggio Emilia, Dept Informat Engn, Via Vignolese 905, I-41100 Modena, Italy. EM rovati.luigi@unimo.it RI Pollonini, Luca/J-9274-2014; Rovati, Luigi/K-3445-2015 OI Pollonini, Luca/0000-0003-2955-6355; Rovati, Luigi/0000-0002-1743-3043 NR 35 TC 12 Z9 12 U1 0 U2 0 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 DEC PY 2004 VL 75 IS 12 BP 5315 EP 5325 DI 10.1063/1.1818588 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 876FX UT WOS:000225483100041 ER PT J AU Wang, YQ Sun, CJ Zhou, E Su, J AF Wang, YQ Sun, CJ Zhou, E Su, J TI Deformation mechanisms of electrostrictive graft elastomer SO SMART MATERIALS & STRUCTURES LA English DT Article ID MM3 FORCE-FIELD; MOLECULAR MECHANICS; HYDROCARBONS AB The electrostrictive graft elastomer is a new type of electroactive polymer. Recently developed by NASA, it consists of flexible backbone chains, each with side chains, called grafts. Neighboring backbone grafts physically cross-link and form crystal units. The flexible backbone chain and the crystal graft unit consist of polarized monomers, which contain atoms with electric partial charges, generating dipole moments. When the elastomer is placed into an electric field, external rotating moments are applied to the dipole moment. This stimulates electrostrictive strain in the graft elastomer. In this paper, the deformation of the elastomer under the action of an electric field is explained by means of two dominant mechanisms: crystal graft unit rotation and backbone chain reorientation. A two-dimensional computational model is established to analyze the deformation. C1 Kansas State Univ, Dept Mech & Nucl Engn, Manhattan, KS 66506 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Wang, YQ (reprint author), Kansas State Univ, Dept Mech & Nucl Engn, Manhattan, KS 66506 USA. EM Wang@mne.ksu.edu NR 9 TC 6 Z9 6 U1 2 U2 11 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0964-1726 J9 SMART MATER STRUCT JI Smart Mater. Struct. PD DEC PY 2004 VL 13 IS 6 BP 1407 EP 1413 AR PII S0964-1726(04)86097-X DI 10.1088/0964-1726/13/6/011 PG 7 WC Instruments & Instrumentation; Materials Science, Multidisciplinary SC Instruments & Instrumentation; Materials Science GA 880WG UT WOS:000225820000011 ER PT J AU Reginald, NL Davila, JM St Cyr, OC AF Reginald, NL Davila, JM St Cyr, OC TI The effects of streamers on the shape of the K-coronal spectrum SO SOLAR PHYSICS LA English DT Article ID TOTAL SOLAR ECLIPSE; ELECTRON-TEMPERATURE; VELOCITY; HOLE AB We conducted an experiment in conjunction with the total solar eclipse of 21 June 2001 in Lusaka, Zambia, to obtain the K-coronal spectrum simultaneously from multiple locations on the solar corona. Then we matched the observed K-coronal spectra with the modeled K-coronal spectra to determine the coronal electron temperature and its bulk flow speed. Here the models assumed a symmetric and isothermal corona with the coronal electron flowing away from the Sun at a constant flow speed. We were able to make remarkable matches between the observations and the models. In this paper we will try to explain how the anomalies in the matches could be accounted for with the introduction of streamers in the K-coronal spectral models. C1 Catholic Univ Amer, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Reginald, NL (reprint author), Catholic Univ Amer, NASA, Goddard Space Flight Ctr, MC 682, Greenbelt, MD 20771 USA. EM reginald@stars.gsfc.nasa.gov NR 15 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD DEC PY 2004 VL 225 IS 2 BP 249 EP 265 DI 10.1007/s11207-004-3516-2 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 913TM UT WOS:000228176100003 ER PT J AU Bozzolo, G Farias, D De Parga, ALV Miranda, R AF Bozzolo, G Farias, D De Parga, ALV Miranda, R TI Modeling of Co/Cu island formation on a Cu(111) surface SO SURFACE REVIEW AND LETTERS LA English DT Article DE computer simulations; copper; cobalt; semi-empirical methods and model calculations; surface alloys; surface structure ID GROWTH; CO; ALLOYS AB The BFS method for alloys is applied to the study of Co growth on Cu(111). Atomistic simulations are performed to investigate the behavior of Co on Cu(111) as a function of temperature. Atom-by-atom analysis of the energy contributions of each atom in the island explain the observed features. C1 Ohio Aerospace Inst, Cleveland, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Autonoma Madrid, Dept Fis Mat Condensada, E-28049 Madrid, Spain. RP Bozzolo, G (reprint author), Ohio Aerospace Inst, 22800 Cedar Point Rd, Cleveland, OH 44142 USA. RI Vazquez de Parga, Amadeo/L-2418-2013; Farias, Daniel/L-2435-2013 OI Vazquez de Parga, Amadeo/0000-0003-0551-1603; Farias, Daniel/0000-0002-8537-8074 NR 14 TC 2 Z9 2 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD DEC PY 2004 VL 11 IS 6 BP 591 EP 597 DI 10.1142/S0218625X0400661X PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 914JR UT WOS:000228224300016 ER PT J AU DellaCorte, C AF DellaCorte, C TI Betrayal denied! 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 DEC PY 2004 VL 60 IS 12 BP 6 EP 6 PG 1 WC Engineering, Mechanical SC Engineering GA 876XA UT WOS:000225530900002 ER PT J AU Lait, LR Newman, PA Schoeberl, MR McGee, T Twigg, L Browell, EV Fenn, MA Grant, WB Butler, CF Bevilacqua, R Davies, J DeBacker, H Andersen, SB Kyro, E Kivi, R von der Gathen, P Claude, H Benesova, A Skrivankova, P Dorokhov, V Zaitcev, I Braathen, G Gil, M Litynska, Z Moore, D Gerding, M AF Lait, LR Newman, PA Schoeberl, MR McGee, T Twigg, L Browell, EV Fenn, MA Grant, WB Butler, CF Bevilacqua, R Davies, J DeBacker, H Andersen, SB Kyro, E Kivi, R von der Gathen, P Claude, H Benesova, A Skrivankova, P Dorokhov, V Zaitcev, I Braathen, G Gil, M Litynska, Z Moore, D Gerding, M TI Non-coincident inter-instrument comparisons of ozone measurements using quasi-conservative coordinates SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID RECONSTRUCTION; VALIDATION; INSTRUMENT; FIELDS; TRENDS; ER-2; AIR AB Ozone measurements from ozonesondes, AROTAL, DIAL, and POAM III instruments during the SOLVE-2/VINTERSOL period are composited in a time-varying, flow-following quasi-conservative (PV-theta) coordinate space; the resulting composites from each instrument are mapped onto the other instruments' locations and times. The mapped data are then used to intercompare data from the different instruments. Overall, the four ozone data sets are found to be in good agreement. AROTAL shows somewhat lower values below 16 km, and DIAL has a positive bias at the upper limits of its altitude range. These intercomparisons are consistent with those obtained from more conventional near-coincident profiles, where available. Although the PV-theta mapping technique entails larger uncertainties of individual profile differences compared to direct near-coincident comparisons, the ability to include much larger numbers of comparisons can make this technique advantageous. C1 Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Langley Res Ctr, Langley, VA USA. SUNARC, San Francisco, CA USA. USN, Res Lab, Washington, DC 20375 USA. Meteorol Serv Canada, Downsview, ON, Canada. Danish Meteorol Inst, Copenhagen, Denmark. Finnish Meteorol Inst, Sodankyla, Finland. Alfred Wegener Inst, Potsdam, Germany. Deutsch Wetterdienst Meteorol Observ, Hohenpeissenberg, Germany. Czech Hydrometeorol Inst, Prague, Czech Republic. Cent Aerol Observ, Dolgoprudnyi, Russia. Norsk Inst Luftforskning, Kjeller, Norway. Inst Nacl Tecn Aeroespacial, Madrid, Spain. Inst Meteorol & Water Management, Legionowo, Poland. UK Meteorol Off, Wokingham, Berks, England. Leibniz Inst Atmospher Phys, Kuhlungsborn, Germany. RP Lait, LR (reprint author), Sci Syst & Applicat Inc, Lanham, MD 20706 USA. EM lait@code916.gsfc.nasa.gov RI von der Gathen, Peter/B-8515-2009; Grant, William/B-8311-2009; Newman, Paul/D-6208-2012; McGee, Thomas/G-4951-2013; andersen, signe/C-4809-2013 OI von der Gathen, Peter/0000-0001-7409-1556; Grant, William/0000-0002-1439-3285; Newman, Paul/0000-0003-1139-2508; andersen, signe/0000-0002-8216-0141 NR 23 TC 8 Z9 9 U1 0 U2 1 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 NOV 30 PY 2004 VL 4 BP 2345 EP 2352 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 875GM UT WOS:000225408300002 ER PT J AU Bangar, MA Ramanathan, K Yun, M Lee, C Hangarter, C Myung, NV AF Bangar, MA Ramanathan, K Yun, M Lee, C Hangarter, C Myung, NV TI Controlled growth of a single palladium nanowire between microfabricated electrodes SO CHEMISTRY OF MATERIALS LA English DT Article ID HYDROGEN SENSOR; METALLIC NANOWIRES; ARRAYS; CONDUCTANCE; FABRICATION AB We report a novel electrochemical method for dimensionally controlled growth of a single palladium nanowire between premicrofabricated electrodes. In this method, the dimensions of the nanowire are defined by the dimensions of the e-beam-patterned channel between the microfabricated gold electrodes. The formation of the nanowire is confirmed by both optical and scanning electron microscopy imaging in addition to the electrical measurement using the two terminal current-voltage (I-V) characteristics of the nanowire. Fabrication of a single localized palladium nanowire with controlled dimensions is demonstrated for 100 nm, 500 nm, and 1 mum wide and 2.5 mum long channels Rength-to-diameter ratio similar to2.5 - 25). The growth profile, confinement, resistance, and morphology of the nanowires were strongly influenced by the deposition conditions. A current of - 100 nA was found to provide well-confined, stable nanowires with ohmic contact with the gold electrodes. C1 Univ Calif Riverside, Dept Chem & Environm Engn, Riverside, CA 92521 USA. Univ Calif Riverside, Ctr Nanoscale Sci & Engn, Riverside, CA 92521 USA. CALTECH, Jet Prop Lab, 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 RI Hangarter, Carlos/M-7924-2016 OI Hangarter, Carlos/0000-0002-7149-0903 NR 20 TC 19 Z9 19 U1 1 U2 13 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 NOV 30 PY 2004 VL 16 IS 24 BP 4955 EP 4959 DI 10.1021/cm048931n PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 874QV UT WOS:000225365800018 ER PT J AU Miller, RL Perlwitz, J Tegen, I AF Miller, RL Perlwitz, J Tegen, I TI Modeling Arabian dust mobilization during the Asian summer monsoon: The effect of prescribed versus calculated SST SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID REFRACTIVE-INDEX; AEROSOLS; CLIMATE; CYCLE AB [ 1] Emission of soil ( or 'mineral') dust aerosol over the Arabian Peninsula during the Northern Hemisphere ( NH) summer monsoon increases in response to dust radiative forcing in an atmospheric general circulation model (AGCM) with prescribed sea surface temperature (SST). Radiative heating within the dust layer reinforces the monsoon circulation, which is further strengthened by column latent heating through a wind-evaporative feedback. The strengthened circulation raises additional dust into the atmosphere over Arabia. In contrast, this positive feedback is absent when SST is calculated by the AGCM using a mixed-layer ocean. This discrepancy results from the surface energy constraint in the mixed-layer experiment, where surface evaporation is decreased by the reduction of sunlight beneath the dust layer. In contrast, evaporation and column latent heating increase in the prescribed SST experiment, where the surface energy constraint is absent. Realization of the positive feedback exhibited by the prescribed SST experiment requires that anomalous ocean heat transport ( which is not included here) balance the surface radiative forcing by dust. C1 Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10025 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Max Planck Inst Biogeochem, Jena, Germany. RP Miller, RL (reprint author), Columbia Univ, Dept Appl Phys & Appl Math, 2880 Broadway, New York, NY 10025 USA. EM rlm15@columbia.edu; jp544@columbia.edu; itegen@tropos.de RI Miller, Ron/E-1902-2012 NR 18 TC 20 Z9 22 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 NOV 30 PY 2004 VL 31 IS 22 AR L22214 DI 10.1029/2004GL020669 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 877PR UT WOS:000225583000001 ER PT J AU Sanchez, BV Haberle, RM Schaeffer, J AF Sanchez, BV Haberle, RM Schaeffer, J TI Atmospheric rotational effects on Mars based on the NASA Ames general circulation model: Angular momentum approach (vol 109, pg E08005, 2004) SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Correction DE atmospheric model; Mars; rotation C1 NASA, Goddard Space Flight Ctr, Terr Phys Lab, Geodynam Branch, Greenbelt, MD 20771 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Sanchez, BV (reprint author), NASA, Goddard Space Flight Ctr, Terr Phys Lab, Geodynam Branch, Code 921, Greenbelt, MD 20771 USA. EM braulio.v.sanchez@nasa.gov RI Sanchez, Braulio/I-5952-2013 NR 1 TC 0 Z9 0 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 NOV 30 PY 2004 VL 109 IS E11 AR E11007 DI 10.1029/2004JE002364 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 877QS UT WOS:000225585700001 ER PT J AU Whitacre, JF West, WC AF Whitacre, JF West, WC TI Crystalline Li3Po4/Li4SiO4 solid solutions as an electrolyte for film batteries using sputtered cathode layers SO SOLID STATE IONICS LA English DT Article; Proceedings Paper CT 14th International Conference on Solid State Ionics CY JUN 22-27, 2003 CL Monterey, CA SP Int Soc Solid State Ion DE crystalline solution; LiPON; solid-state electrolyte AB Crystalline solid solutions of 1:1 Li3PO4/Li4SiO4 were synthesized and tested electrochemically using thin film physical vapor deposited electrodes. After cathode deposition, the electrolyte/cathode structures were annealed at 700 degreesC for 2 h-a process that resulted in cathode crystallization without encouraging deleterious interfacial reactions. Results indicate that the electrolyte functioned well in this configuration. Test cells were taken through multiple charge/discharge cycles at different rates and temperatures and demonstrated a marked enhancement in performance parameters in comparison to previous reports. It is suggested that this material could function well in Li batteries fabricated using proper form factors. (C) 2004 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Whitacre, JF (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM whitacre@jpl.nasa.gov NR 5 TC 9 Z9 10 U1 3 U2 29 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD NOV 30 PY 2004 VL 175 IS 1-4 SI SI BP 251 EP 255 DI 10.1016/j.ssi.2003.11.034 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 883DM UT WOS:000225990500050 ER PT J AU Fioletov, VE Kimlin, MG Krotkov, N McArthur, LJB Kerr, JB Wardle, DI Herman, JR Meltzer, R Mathews, TW Kaurola, J AF Fioletov, VE Kimlin, MG Krotkov, N McArthur, LJB Kerr, JB Wardle, DI Herman, JR Meltzer, R Mathews, TW Kaurola, J TI UV index climatology over the United States and Canada from ground-based and satellite estimates SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE UV index; Brewer; TOMS; pyranometer; climatology; ozone ID LONG-TERM VARIATIONS; TOTAL OZONE; SUNSHINE DURATION; EARTHS SURFACE; IRRADIANCE; RADIATION; TOMS; CLOUDS; SNOW; MODEL AB Long-term monthly mean UV index values for Canada and the United States were calculated using information from two sources: from noon erythemal UV estimated from Total Ozone Mapping Spectrometer (TOMS) total ozone and reflectivity data and from UV index values derived from observations of global solar radiation, total ozone, dew point, and snow cover. The results are presented as monthly maps of mean noon UV index values. Mean UV index values in summer range from 1.5 in the Arctic to 11.5 over southern Texas. Both climatologies were validated against spectral UV irradiance measurements made by Brewer spectrophotometers. With snow on the ground the TOMS-based data underestimate UV by up to 60% with respect to Brewer measurements and UV derived from global solar radiation and other parameters. In summer, TOMS UV index climatology values are from 10 to 30% higher than those derived from global solar radiation and other parameters. The difference is probably related to aerosol absorption and pollution effects in the lower troposphere that are not currently detected from space. For 21 of 28 midlatitude Brewer sites, long-term mean summer UV measured values and UV derived from global solar radiation and other parameters agree to within +5 to -7%. The remaining seven sites are located in 'clean'' environments where TOMS estimates agree with Brewer measurements while UV derived from global solar radiation and other parameters is 10-13% lower. Brewer data also demonstrate that clean and "typical'' sites can be as little as 70-120 km apart. C1 Univ Georgia, Natl Ultraviolet Monitoring Ctr, Dept Phys & Astron, Athens, GA 30606 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. Meteorol Serv Canada, Expt Studies Div, Air Qual Res, Downsview, ON M3H 5T4, Canada. RP Fioletov, VE (reprint author), Meteorol Serv Canada, Expt Studies Div, Air Qual Res, 4905 Dufferin St, Downsview, ON M3H 5T4, Canada. EM vitali.fioletov@ec.gc.ca RI Krotkov, Nickolay/E-1541-2012 OI Krotkov, Nickolay/0000-0001-6170-6750 NR 45 TC 19 Z9 19 U1 0 U2 5 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 NOV 25 PY 2004 VL 109 IS D22 AR D22308 DI 10.1029/2004JD004820 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 875OM UT WOS:000225430100001 ER PT J AU Wu, DL Zhang, FQ AF Wu, DL Zhang, FQ TI A study of mesoscale gravity waves over the North Atlantic with satellite observations and a mesoscale model SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE mesoscale gravity waves; North Atlantic; satellite observations ID NUMERICAL SIMULATIONS; MIDDLE ATMOSPHERE; GENERAL-CIRCULATION; MOUNTAIN WAVES; UNITED-STATES; EVENT; DYNAMICS; STRATOSPHERE; DRAG; PARAMETERIZATION AB Satellite microwave data are used to study gravity wave properties and variabilities over the northeastern United States and the North Atlantic in the December-January periods. The gravity waves in this region, found in many winters, can reach the stratopause with growing amplitude. The Advanced Microwave Sounding Unit-A (AMSU-A) observations show that the wave occurrences are correlated well with the intensity and location of the tropospheric baroclinic jet front systems. To further investigate the cause(s) and properties of the North Atlantic gravity waves, we focus on a series of wave events during 19-21 January 2003 and compare AMSU-A observations to simulations from a mesoscale model (MM5). The simulated gravity waves compare qualitatively well with the satellite observations in terms of wave structures, timing, and overall morphology. Excitation mechanisms of these large-amplitude waves in the troposphere are complex and subject to further investigations. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. RP Wu, DL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM dwu@mls.jpl.nasa.gov RI Zhang, Fuqing/E-6522-2010; Wu, Dong/D-5375-2012 OI Zhang, Fuqing/0000-0003-4860-9985; NR 36 TC 44 Z9 45 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 NOV 25 PY 2004 VL 109 IS D22 AR D22104 DI 10.1029/2004JD005090 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 875OM UT WOS:000225430100003 ER PT J AU Ohmoto, H Watanabe, Y AF Ohmoto, H Watanabe, Y TI Palaeoclimatology - Archaean palaeosols and Archaean air - Reply SO NATURE LA English DT Editorial Material ID CARBON-DIOXIDE CONCENTRATIONS; BILLION YEARS AGO; ATMOSPHERE; SEDIMENTS; ISOTOPES; OXYGEN; RICH C1 NASA, Astrobiol Inst, Astrobiol Res Ctr, University Pk, PA 16802 USA. Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. RP Ohmoto, H (reprint author), NASA, Astrobiol Inst, Astrobiol Res Ctr, University Pk, PA 16802 USA. EM ohmoto@geosc.psu.edu NR 15 TC 1 Z9 1 U1 1 U2 5 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD NOV 25 PY 2004 VL 432 IS 7016 DI 10.1038/nature03168 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 874AA UT WOS:000225322100035 ER PT J AU Gettelman, A Weinstock, EM Fetzer, EJ Irion, FW Eldering, A Richard, EC Rosenlof, KH Thompson, TL Pittman, JV Webster, CR Herman, RL AF Gettelman, A Weinstock, EM Fetzer, EJ Irion, FW Eldering, A Richard, EC Rosenlof, KH Thompson, TL Pittman, JV Webster, CR Herman, RL TI Validation of Aqua satellite data in the upper troposphere and lower stratosphere with in situ aircraft instruments SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RELATIVE-HUMIDITY; AIRS/AMSU/HSB; OZONE; SPECTROMETER; CLOUDS; WATER AB Aircraft observations from a recent campaign spanning 0-40N latitude are compared to coincident observations from satellite sensors on board the Aqua satellite of temperature, ozone, water vapor and cloud properties in the upper troposphere and lower stratosphere. Satellite observations compare well to aircraft data; temperature is generally within +/-1.5 K and water vapor is within +/-25% of aircraft observations for pressures above 150 hPa and mixing ratios above similar to10 ppmv. Satellite ozone has a positive bias in the upper troposphere, and clouds observed by the aircraft are qualitatively well represented in the satellite data. These data and analyses provide critical validation of satellite observations, which promise new global insights into this region of the atmosphere. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. RP Gettelman, A (reprint author), Natl Ctr Atmospher Res, POB 3000, Boulder, CO 80307 USA. EM andrew@ucar.edu; elliot@huarp.harvard.edu; eric.j.fetzer@jpl.nasa.gov; bill.irion@jpl.nasa.gov; annmarie.eldering@jpl.nasa.gov; erik.c.richard@noaa.gov; karen.h.rosenlof@noaa.gov; thomas.l.thompson@noaa.gov; vellovic@fas.harvard.edu; chris.r.webster@jpl.nasa.gov; robert.l.herman@jpl.nasa.gov RI Herman, Robert/H-9389-2012; Rosenlof, Karen/B-5652-2008 OI Herman, Robert/0000-0001-7063-6424; Rosenlof, Karen/0000-0002-0903-8270 NR 14 TC 60 Z9 63 U1 2 U2 11 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 NOV 24 PY 2004 VL 31 IS 22 AR L22107 DI 10.1029/2004GL020730 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 875OB UT WOS:000225428900001 ER PT J AU Work, TM Balazs, GH Rameyer, RA Morris, RA AF Work, TM Balazs, GH Rameyer, RA Morris, RA TI Retrospective pathology survey of green turtles Chelonia mydas with fibropapillomatosis in the Hawaiian Islands, 1993-2003 SO DISEASES OF AQUATIC ORGANISMS LA English DT Article DE green turtle; Chelonia mydas; fibropapillomatosis; pathology; epizootiology ID CUTANEOUS FIBROPAPILLOMAS; MARINE TURTLES; TRANSMISSION; HERPESVIRUS; SPIRORCHIDIASIS; IDENTIFICATION; ASSOCIATION; MALIGNANCY; FLORIDA; MARKER AB We necropsied 255 stranded green turtles Chelonia mydas with fibropapillomatosis (FP) from the Hawaiian Islands, North Pacific, from August 1993 through May 2003. Of these, 214 (84%) were euthanized due to advanced FP and the remainder were found dead in fresh condition. Turtles were assigned a standardized tumor severity score ranging from 1 (lightly tumored) to 3 (heavily tumored). Tumors were counted and measured and categorized as external, oral, or internal and tissues evaluated by light microscopy. Turtles in tumor score 2 and 3 categories predominated, and tumor score 3 turtles were significantly larger than the other 2 categories. More juveniles stranded than subadults or adults. Total cross-sectional area of tumors increased significantly with straight carapace length (SCL). Frequency distribution of total number of external tumors per turtle was significantly skewed to the right, and there were significantly more tumors at the front than Fear of turtles. Eighty percent of turtles had oral tumors, and 51% of turtles with oral tumors had tumors in the glottis. Thirty-nine percent of turtles had internal tumors, most of them in the lung, kidney and heart. Fibromas predominated in lung, kidney and musculoskeletal system whereas myxofibromas were more common in intestines and spleen. Fibrosarcomas of low-grade malignancy were most frequent in the heart, and heart tumors had a predilection for the right atrium. Turtles with FP had significant additional complications including inflammation with vascular flukes. bacterial infections, poor body condition, and necrosis of salt gland. Turtles with oral tumors were more likely to have secondary complications such as pneumonia. Most turtles came from the island of Oahu (74%) followed by Maui (20%), Hawaii, Molokai, and Lanai (<3% each). On Oahu, significantly more turtles we necropsied stranded along the northwestern and northeastern shores. C1 US Geol Survey, Natl Wildlife Hlth Ctr, Hawaii Field Stn, Honolulu, HI 96850 USA. Natl Marine Fisheries Serv, Isl Fisheries Sci Ctr, Honolulu, HI 96822 USA. Makai Anim Clin, Kailua, HI 96734 USA. RP Work, TM (reprint author), US Geol Survey, Natl Wildlife Hlth Ctr, Hawaii Field Stn, 300 Ala Moana Blvd,Room 5-231, Honolulu, HI 96850 USA. EM thierry_work@usgs.gov RI Work, Thierry/F-1550-2015 OI Work, Thierry/0000-0002-4426-9090 NR 58 TC 40 Z9 46 U1 0 U2 18 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0177-5103 J9 DIS AQUAT ORGAN JI Dis. Aquat. Org. PD NOV 23 PY 2004 VL 62 IS 1-2 BP 163 EP 176 DI 10.3354/dao062163 PG 14 WC Fisheries; Veterinary Sciences SC Fisheries; Veterinary Sciences GA 892WO UT WOS:000226680900018 PM 15648843 ER PT J AU Johnston, S Romani, RW Marshall, FE Zhang, W AF Johnston, S Romani, RW Marshall, FE Zhang, W TI Radio and X-ray observations of PSR B0540-69 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE pulsars : individual : PSR B0540-69 ID LARGE-MAGELLANIC-CLOUD; PSR B0540-69; GIANT PULSES; RXTE OBSERVATIONS; BRAKING INDEX; SINGLE PULSES; CRAB PULSAR; GAMMA-RAY; EMISSION; B1937+21 AB PSR B0540 69 is one of a small handful of pulsars known to emit giant pulses and the only extra-galactic pulsar known to do so. We observed the pulsar for a total of 72 h over a 6 month interval and detected 141 giant pulses. We have obtained correct phasing between the radio arrival times of the giant pulses and the X-ray pulse profile. The giant pulses occur in two phase windows, located 6.7 ms before and 5.0 ms after the mid-point of the X-ray profile. We have detected the integrated profile of the pulsar at 1.4 GHz with a flux density of only 24 muJy. The statistics of the giant pulses are clearly power law and it is likely that the giant pulses contribute only a few per cent of the integrated pulse flux density, similar to other pulsars with giant pulse emission. Simultaneous X-ray and radio observations show no significant increase in the X-ray flux at the time of the radio giants. The relative enhancements in the X-ray emission must be at least 5.5 times smaller than in the radio emission. C1 Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia. Stanford Univ, Dept Phys, Stanford, CA 94305 USA. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Johnston, S (reprint author), Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia. EM simonj@physics.usyd.edu.au NR 20 TC 18 Z9 18 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 NOV 21 PY 2004 VL 355 IS 1 BP 31 EP 36 DI 10.1111/j.1365-2966.2004.08286.x PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 870MQ UT WOS:000225061700006 ER PT J AU Lay, OP AF Lay, OP TI Systematic errors in nulling interferometers SO APPLIED OPTICS LA English DT Article ID EXTRASOLAR PLANETS; SEARCH AB Nulling interferometers combine on-axis suppression with high angular resolution, making them ideal instruments for the direct detection of faint planets close to their parent star. Analysis is developed to show that it is systematic errors, resulting from fluctuations in the null depth, that drive the instrument performance. A second-order combination of amplitude and phase errors is the dominant contributor. In the calculated example, the detection of an Earthlike planet around a Sunlike star at 15 pc requires that the arms of the interferometer must be phased to within similar to1.5 nm and have their amplitudes matched to similar to0.1%. (C) 2004 Optical Society of America. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lay, OP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM oliver.p.lay@jpl.nasa.gov NR 17 TC 42 Z9 42 U1 0 U2 0 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 NOV 20 PY 2004 VL 43 IS 33 BP 6100 EP 6123 DI 10.1364/AO.43.006100 PG 24 WC Optics SC Optics GA 876XH UT WOS:000225531600006 PM 15605550 ER PT J AU Yan, HJ Dickinson, M Eisenhardt, PRM Ferguson, HC Grogin, NA Paolillo, M Chary, RR Casertano, S Stern, D Reach, WT Moustakas, LA Fall, SM AF Yan, HJ Dickinson, M Eisenhardt, PRM Ferguson, HC Grogin, NA Paolillo, M Chary, RR Casertano, S Stern, D Reach, WT Moustakas, LA Fall, SM TI High-redshift extremely red objects in the Hubble Space Telescope Ultra Deep Field revealed by the GOODS infrared array camera observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; galaxies : evolution; galaxies : luminosity function, mass function; infrared : galaxies ID ENERGY-DISTRIBUTIONS; GALAXIES; SOUTH; STELLAR AB Using early data from the Infrared Array Camera (IRAC) on the Spitzer Space Telescope, taken for the Great Observatories Origins Deep Survey ( GOODS), we identify and study objects that are well detected at 3.6 mum but are very faint ( and in some cases, invisible) in the Hubble Ultra Deep Field (HUDF) ACS and NICMOS images and in very deep VLT K-s-band imaging. We select a sample of 17 objects with f(nu)(3.6 mum)/f(nu)(z(850)) > 20. The analysis of their spectral energy distributions (SEDs) from 0.4 to 8.0 mum shows that the majority of these objects cannot be satisfactorily explained without a well-evolved stellar population. We find that most of them can be well fitted by a simple two-component model, where the primary component represents a massive, old population that dominates the strong IR emission, while the secondary component represents a low-amplitude, on-going star formation process that accounts for the weak optical fluxes. Their estimated photometric redshifts (z(p)) range from 1.6 to 2.9 with the median at z(p) = 2.4. For the simple star formation histories considered here, their corresponding stellar masses range from (0.1 - 1.6) x 10(11) M-. for a Chabrier initial mass function ( IMF). Their median rest-frame K-s-band absolute magnitude is - 22.9 mag in the AB system, or 1.5 x L*(K) for present-day elliptical galaxies. In the scenario of pure luminosity evolution, such objects may be direct progenitors for at least 14% - 51% of the local population of early type galaxies. Because of the small cosmic volume of the HUDF, however, this simple estimate could be affected by other effects, such as cosmic variance and the strong clustering of massive galaxies. A full analysis of the entire GOODS area is now under way to assess such effects. C1 CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Natl Opt Astron Observ, Tucson, AZ 85719 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Naples Federico II, Dipartimento Sci Fisiche, I-80126 Naples, Italy. RP Yan, HJ (reprint author), CALTECH, Spitzer Sci Ctr, MS 100-22, Pasadena, CA 91125 USA. EM yhj@ipac.caltech.edu RI Paolillo, Maurizio/J-1733-2012; OI Paolillo, Maurizio/0000-0003-4210-7693; Reach, William/0000-0001-8362-4094 NR 31 TC 105 Z9 105 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 NOV 20 PY 2004 VL 616 IS 1 BP 63 EP 70 DI 10.1086/424898 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 872HY UT WOS:000225199500006 ER PT J AU Horiuchi, S Fomalont, EB Scott, WK Taylor, AR Lovell, JEJ Moellenbrock, GA Dodson, R Murata, Y Hirabayashi, H Edwards, PG Gurvits, LI Shen, ZQ AF Horiuchi, S Fomalont, EB Scott, WK Taylor, AR Lovell, JEJ Moellenbrock, GA Dodson, R Murata, Y Hirabayashi, H Edwards, PG Gurvits, LI Shen, ZQ TI The VSOP 5 GHz active galactic nucleus survey. IV. The angular size/brightness temperature distribution SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; radio continuum : galaxies; surveys; techniques : interferometric ID EXTRAGALACTIC RADIO-SOURCES; PEARSON-READHEAD SURVEY; SPACE VLBI; VARIABILITY SURVEY; STATISTICS; AGN AB The VLBI Space Observatory Programme (VSOP) mission is a Japanese-led project to study radio sources with submilliarcsecond angular resolution, using an orbiting 8 m telescope on board the satellite HALCA with a global Earth-based array of telescopes. A major program is the 5 GHz VSOP Survey Program, which we supplement here with Very Long Baseline Array observations to produce a complete and flux density - limited sample. Using statistical methods of analysis of the observed visibility amplitude versus projected (u, v) spacing, we have determined the angular size and brightness temperature distribution of bright radio emission from active galactic nuclei. On average, the cores have a diameter ( full width, half-power) of 0.20 mas, which contains about 20% of the total source emission, and 14% +/- 6% of the cores are less than 0.04 mas in size. About 20% +/- 5% of the radio cores have a source frame brightness temperature T-b > 1.0 x 10(13) K, and 3% +/- 2% have T-b > 1.0 x 10(14) K. A model of the high brightness temperature tail suggests that the radio cores have brightness temperatures approximate to1 x 10(12) K and are beamed toward the observer with an average bulk motion of beta = 0.993 +/- 0.004. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Natl Astron Observ, Tokyo 181, Japan. Swinburne Univ Technol, Ctr Astrophys & Supercomp, Hawthorn, Vic 2133, Australia. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Univ Calgary, Calgary, AB, Canada. Australia Telescope Natl Facil, Canberra, ACT, Australia. Natl Radio Astron Observ, Socorro, NM 87801 USA. Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Joint Inst VLBI Europe, Dwingeloo, Netherlands. Chinese Acad Sci, Shanghai Astron Observ, Shanghai 200030, Peoples R China. RP Horiuchi, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM shoriuchi@swin.edu.au; efomalon@nrao.edu; bill@ras.ucalgary.ca; russ@ras.ucalgary.ca; jim.lovell@csiro.au; gmoellen@nrao.edu; rdodson@vsop.isas.jaxa.jp; murata@vsop.isas.jaxa.jp; hirax@vsop.isas.jaxa.jp; pge@vsop.isas.jaxa.jp; lgurvits@jive.nl; zshen@shao.ac.cn NR 32 TC 34 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 NOV 20 PY 2004 VL 616 IS 1 BP 110 EP 122 DI 10.1086/424811 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 872HY UT WOS:000225199500009 ER PT J AU Treister, E Urry, CM Chatzichristou, E Bauer, F Alexander, DM Koekemoer, A Van Duyne, J Brandt, WN Bergeron, J Stern, D Moustakas, LA Chary, RR Conselice, C Cristiani, S Grogin, N AF Treister, E Urry, CM Chatzichristou, E Bauer, F Alexander, DM Koekemoer, A Van Duyne, J Brandt, WN Bergeron, J Stern, D Moustakas, LA Chary, RR Conselice, C Cristiani, S Grogin, N TI Obscured active galactic nuclei and the X-ray, optical, and far-infrared number counts of active galactic nuclei in the GOODS fields SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; quasars : general; X-rays : diffuse background ID SERENDIPITOUS CHANDRA SOURCES; SEYFERT 2 GALAXIES; DIGITAL SKY SURVEY; NORTH SURVEY; HELLAS2XMM SURVEY; ENERGY-DISTRIBUTIONS; LUMINOSITY FUNCTION; SPECTRAL-ANALYSIS; REDSHIFT SURVEY; SOURCE CATALOGS AB The deep X-ray, optical, and far-infrared fields that constitute the Great Observatories Origins Deep Survey (GOODS) are sensitive to obscured active galactic nuclei (AGNs; NH greater than or similar to 10(22) cm(-2)) at the quasar epoch (z similar to 2 3), as well as to unobscured AGNs as distant as z similar to 7. Luminous X-ray emission is a sign of accretion onto a supermassive black hole and thus reveals all but the most heavily obscured AGNs. We combine X-ray luminosity functions with appropriate spectral energy distributions for AGNs to model the X-ray, optical, and far-infrared flux distributions of the X-ray sources in the GOODS fields. A simple model based on the unified paradigm for AGNs, with similar to3 times as many obscured AGNs as unobscured, successfully reproduces the z-band flux distributions measured in the deep Hubble Space Telescope ACS observations of the GOODS-North and GOODS-South fields. This model is also consistent with the observed spectroscopic and photometric redshift distributions once selection effects are considered. The previously reported discrepancy between observed spectroscopic redshift distributions and the predictions of population synthesis models for the X-ray background can be explained by a bias against the most heavily obscured AGNs generated by both X-ray observations and the identification of sources via optical spectroscopy. We predict the AGN number counts for Spitzer MIPS 24 mum and IRAC 3.6 - 8 mum observations in the GOODS fields, which will verify whether most AGNs in the early universe are obscured in the optical. Such AGNs should be very bright far-infrared sources and include some obscured AGNs missed even by X-ray observations. C1 Yale Univ, Yale Ctr Astron & Astrophys, New Haven, CT 06520 USA. Univ Chile, Dept Astron, Santiago, Chile. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Inst Astrophys, F-75014 Paris, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. CALTECH, Pasadena, CA 91125 USA. Osserv Astron Trieste, INAF, I-34131 Trieste, Italy. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RP Yale Univ, Yale Ctr Astron & Astrophys, POB 208121, New Haven, CT 06520 USA. EM treister@astro.yale.edu RI Conselice, Christopher/B-4348-2013; Urry, Claudia/G-7381-2011; Brandt, William/N-2844-2015; OI Urry, Claudia/0000-0002-0745-9792; Brandt, William/0000-0002-0167-2453; Cristiani, Stefano/0000-0002-2115-5234; Conselice, Christopher/0000-0003-1949-7638; Koekemoer, Anton/0000-0002-6610-2048; Moustakas, Leonidas/0000-0003-3030-2360; Alexander, David/0000-0002-5896-6313 NR 76 TC 124 Z9 124 U1 0 U2 4 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 NOV 20 PY 2004 VL 616 IS 1 BP 123 EP 135 DI 10.1086/424891 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 872HY UT WOS:000225199500010 ER PT J AU Soglasnov, VA Popov, MV Bartel, N Cannon, W Novikov, AY Kondratiev, VI Altunin, VI AF Soglasnov, VA Popov, MV Bartel, N Cannon, W Novikov, AY Kondratiev, VI Altunin, VI TI Giant pulses from PSR B1937+21 with widths <= 15 nanoseconds and T-b >= 5 x 10(39) K, the highest brightness temperature observed in the universe SO ASTROPHYSICAL JOURNAL LA English DT Article DE methods : data analysis; pulsars : general; pulsars : individual (PSR B1937+21); radio continuum : stars; stars : neutron ID TIME RESOLUTION OBSERVATIONS; DUAL-FREQUENCY OBSERVATIONS; MILLISECOND PULSAR; RADIO PULSES; CRAB PULSAR; EMISSION; MICROSTRUCTURE; MHZ; POLARIZATION; PLASMA AB Giant radio pulses of the millisecond pulsar B1937+21 were recorded with the S2 VLBI system at 1.65 GHz with NASA/JPL's 70 m radio telescope at Tidbinbilla, Australia. These pulses have been observed as strong as 65,000 Jy with widths less than or equal to15 ns, corresponding to a brightness temperature of T(b)greater than or equal to5x10(39) K, the highest observed in the universe. The vast majority of these pulses occur in 5.8 and 8.2 mus windows at the very trailing edges of the regular main pulse and interpulse profiles, respectively. Giant pulses occur, in general, with a single spike. Only in one case of 309 was the structure clearly more complex. The cumulative distribution is fitted by a power law with index -1.40+/-0.01 with a low-energy but no high-energy cutoff. We estimate that giant pulses occur frequently but are only rarely detected. When corrected for the directivity factor, 25 giant pulses are estimated to be generated in one neutron star revolution alone. The intensities of the giant pulses of the main pulses and interpulses are not correlated with each other nor with the intensities or energies of the main pulses and interpulses themselves. Their radiation energy density can exceed 300 times the plasma energy density at the surface of the neutron star and can even exceed the magnetic field energy density at that surface. We therefore do not think that the generation of giant pulses is linked to the plasma mechanisms in the magnetosphere. Instead we suggest that it is directly related to discharges in the polar cap region of the pulsar. C1 PN Lebedev Phys Inst, Ctr Astro Space, Moscow 117997, Russia. York Univ, Dept Phys & Astron, N York, ON M3J 1P3, Canada. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Soglasnov, VA (reprint author), PN Lebedev Phys Inst, Ctr Astro Space, Profsoyuznaya 84-32, Moscow 117997, Russia. EM vsoglasn@asc.rssi.ru; mpopov@asc.rssi.ru; bartel@yorku.ca; wayne@sgl.sci.yorku.ca; valery.i.altunin@jpl.nasa.gov; vlad@asc.rssi.ru RI Popov, Mikhail/M-6118-2015; Soglasnov, Vladimir/O-7615-2015; Kondratiev, Vladislav/N-1105-2015 OI Kondratiev, Vladislav/0000-0001-8864-7471 NR 47 TC 60 Z9 63 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 NOV 20 PY 2004 VL 616 IS 1 BP 439 EP 451 DI 10.1086/424908 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 872HY UT WOS:000225199500036 ER PT J AU Inam, SC Baykal, A Swank, J Stark, MJ AF Inam, SC Baykal, A Swank, J Stark, MJ TI Discovery of a soft spectral component and transient 22.7 second quasi-periodic oscillations of SAX J2103.5+4545 SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : individual (SAX J2103.5+4545); stars : neutron; X-rays : binaries; X-rays : stars ID X-RAY PULSARS; MILLISECOND PULSAR; EXO 2030+375; APERIODIC VARIABILITY; CENTAURUS X-3; GRO J1744-28; 4U 1907+09; SPECTROSCOPY; HERCULES-X-1; ACCRETION AB XMM-Newton observed SAX J2103.5+4545 on 2003 January 6, while the Rossi X-Ray Timing Explorer (RXTE) was also monitoring the source. Using the RXTE Proportional Counter Array data set between 2002 December 3 and 2003 January 29, the spin period and average spin-up rate during the XMM-Newton observations were found to be 354.7940+/-0.0008 s and (7.4+/-0.9)x10(-13) Hz s(-1), respectively. In the power spectrum of the 0.9-11 keV EPIC PN light curve, we found quasi-periodic oscillations (QPOs) around 0.044 Hz (22.7 s) with an rms fractional amplitude of similar to6.6%. We interpreted this QPO feature as the Keplerian motion of inhomogeneities through the inner disk. In the X-ray spectrum, in addition to the power-law component with high-energy cutoff and the similar to6.4 keV fluorescent iron emission line, we discovered a soft component consistent with blackbody emission with kTsimilar to1.9 keV. The pulse phase spectroscopy of the source revealed that the blackbody flux peaked at the peak of the pulse with an emission radius of similar to0.3 km, suggesting the polar cap on the neutron star surface as the source of the blackbody emission. The flux of the iron emission line at similar to6.42 keV was shown to peak at the off-pulse phase, supporting the idea that this feature arises from fluorescent emission of the circumstellar material around the neutron star rather than the hot region in the vicinity of the neutron star polar cap. C1 Middle E Tech Univ, Dept Phys, TR-06531 Ankara, Turkey. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Lafayette Coll, Dept Phys, Easton, PA 18042 USA. RP Middle E Tech Univ, Dept Phys, TR-06531 Ankara, Turkey. EM scinam@metu.edu.tr; altan@astroa.physics.metu.edu.tr; swank@xenos.gsfc.nasa.gov; starkm@lafayette.edu RI Swank, Jean/F-2693-2012 NR 44 TC 19 Z9 19 U1 0 U2 4 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 NOV 20 PY 2004 VL 616 IS 1 BP 463 EP 468 DI 10.1086/424825 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 872HY UT WOS:000225199500038 ER PT J AU Contreras, CS de Paz, AG Sahai, R AF Contreras, CS de Paz, AG Sahai, R TI The companion to the central mira star of the protoplanetary nebula OH 231.8+4.2 SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; circumstellar matter; stars : AGB and post-AGB; stars : individual (OH 231.8+4.2); stars : mass loss; stars : variables : other ID SIO MASER EMISSION; PLANETARY-NEBULAE; BIPOLAR OUTFLOW; SYMBIOTIC MIRAS; OH 231.8+4.2; OH231.8+4.2; AGB; SPECTRA; SYSTEM; JETS AB We present deep optical long-slit spectra of the peculiar protoplanetary nebula (PPN) OH 231.8+4.2 obtained with the 6.5 m Baade Telescope at Las Campanas Observatory (Chile). In addition to the molecular absorption bands characteristic of the M9-10 III star inside OH 231.8+4.2 (QX Pup), we identify lines of the Balmer series in absorption, which do not form in the cool atmospheres of late M-type stars. We also confirm the presence of a blue continuum excess with an intensity that is a factor similar to30 larger than that expected for an M9-10 III star. Our results indicate the presence of a source hotter than QX Pup illuminating OH 231.8+4.2 that is likely a main-sequence star with spectral type A. We discuss how the formation and nebular evolution of OH 231.8+4.2 could have been affected by the presence of a binary system in its core. C1 CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Contreras, CS (reprint author), CALTECH, Div Phys Math & Astron, MS 105-24,1200 E Calif Blvd, Pasadena, CA 91125 USA. EM sanchez@astro.caltech.edu; agpaz@ociw.edu; sahai@eclipse.jpl.nasa.gov RI Sanchez-Contreras, Carmen/N-3718-2015; OI Sanchez-Contreras, Carmen/0000-0002-6341-592X; Gil de Paz, Armando/0000-0001-6150-2854 NR 36 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 NOV 20 PY 2004 VL 616 IS 1 BP 519 EP 524 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 872HY UT WOS:000225199500043 ER PT J AU Kuan, YJ Huang, HC Charnley, SB Hirano, N Takakuwa, S Wilner, DJ Liu, SY Ohashi, N Bourke, TL Qi, CH Zhang, QH AF Kuan, YJ Huang, HC Charnley, SB Hirano, N Takakuwa, S Wilner, DJ Liu, SY Ohashi, N Bourke, TL Qi, CH Zhang, QH TI Organic molecules in low-mass protostellar hot cores: Submillimeter imaging of IRAS 16293-2422 SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrochemistry; ISM : abundances; ISM : individual (IRAS 16293-2422); ISM : molecules; radio lines : ISM; stars : formation ID IRAS-16293-2422; EMISSION AB Arcsecond-resolution spectral observations toward the protobinary system IRAS 16293-2422 at 344 and 354 GHz were conducted using the Submillimeter Array. Several complex organic molecules, such as CH3OH and HCOOCH3, were detected and mapped. Together with the rich organic inventory revealed, it clearly indicates the existence of two, rather than one, compact hot molecular cores (less than or similar to400 AU in radius) associated with each of the protobinary components identified by their dust continuum emission in the inner star-forming core. C1 Natl Taiwan Normal Univ, Dept Earth Sci, Taipei 116, Taiwan. Acad Sinica, Inst Astron & Astrophys, Taipei 106, Taiwan. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Harvard Smithsonian Ctr Astrophys, Submillimeter Array Project, Hilo, HI 96721 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Kuan, YJ (reprint author), Natl Taiwan Normal Univ, Dept Earth Sci, 88 Sect 4,Ting Chou Rd, Taipei 116, Taiwan. EM kuan@sgrb2.geos.ntnu.edu.tw; hspring@sgrb2.geos.ntnu.edu.tw; charnley@dusty.arc.nasa.gov; hirano@asiaa.sinica.edu.tw; stakakuw@sma.hawaii.edu; dwilner@cfa.harvard.edu; syliu@asiaa.sinica.edu.tw; ohashi@asiaa.sinica.edu.tw; tbourke@cfa.harvard.edu; cqi@cfa.harvard.edu; qzhang@cfa.harvard.edu RI Charnley, Steven/C-9538-2012; OI Zhang, Qizhou/0000-0003-2384-6589 NR 11 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 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 2004 VL 616 IS 1 BP L27 EP L30 DI 10.1086/426315 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 872IB UT WOS:000225199800007 ER PT J AU Estep, L Terrie, G Davis, B AF Estep, L Terrie, G Davis, B TI Crop stress detection using AVIRIS hyperspectral imagery and artificial neural networks SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID LEAF REFLECTANCE; VEGETATION AB The objectives of this study were to compare the results of artificial neural network (ANN) and standard vegetation algorithm processing to distinguish nutrient stress from in-field controls, and determine whether nutrient stress might be distinguished from water stress in the same test field. The test site was the US Department of Agriculture's Variable Rate Application (VRAT) site, Shelton, Nebraska. The VRAT field was planted in corn with test plots that were differentially treated with nitrogen (N). The field contained four replicates, each with N treatments ranging from 0 kg ha(-1) to 200 kg ha(-1) in 50 kg ha(-1) increments. Low-altitude (3 m pixel) Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) hyperspectral imagery (224 bands) was collected over the site. Ground data were collected to support image interpretation. An ANN was applied to the AVIRIS image data for detection of crop and water stress. Known vegetation indices were used as a baseline for comparison against ANN-based stress detection. The resulting comparison found that ANN methods provided a heightened capability to separate stressed crops from in-field, non-stressed controls and was sensitive to differences in nutrient- and water-stressed field regions. C1 Lockheed Martin Technol Serv Grp, Edison, NJ 08837 USA. Lockheed Martin Space Operat, Stennis Programs, Stennis Space Ctr, MS 39529 USA. NASA, Stennis Space Ctr, MS 39529 USA. RP Estep, L (reprint author), Lockheed Martin Technol Serv Grp, 5706 Devlin Pl, Midland, TX 79707 USA. EM lestep@cox.net NR 17 TC 8 Z9 8 U1 0 U2 4 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 NOV 20 PY 2004 VL 25 IS 22 BP 4999 EP 5004 DI 10.1080/01431160412331291242 PG 6 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 873ZZ UT WOS:000225322000010 ER PT J AU Abdalati, W Krabill, W Frederick, E Manizade, S Martin, C Sonntag, J Swift, R Thomas, R Yungel, J Koerner, R AF Abdalati, W Krabill, W Frederick, E Manizade, S Martin, C Sonntag, J Swift, R Thomas, R Yungel, J Koerner, R TI Elevation changes of ice caps in the Canadian Arctic Archipelago SO JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE LA English DT Article DE ice caps; Arctic; mass balance ID LASER ALTIMETRY; AIR-TEMPERATURE; ENERGY-BALANCE; BAFFIN-ISLAND; SEA-LEVEL; SHEET; GLACIER; ABLATION; ACCURACY; MARGIN AB [1] Precise repeat airborne laser surveys were conducted over the major ice caps in the Canadian Arctic Archipelago in the spring of 1995 and 2000 in order to measure elevation changes in the region. Our measurements reveal thinning at lower elevations ( below 1600 m) on most of the ice caps and glaciers but either very little change or thickening at higher elevations in the ice cap accumulation zones. Recent increases in precipitation in the area can account for the slight thickening where it was observed but not for the thinning at lower elevations. For the northern ice caps on the Queen Elizabeth Islands, thinning was generally < 0.5 m yr(-1), which is consistent with what would be expected from the warm temperature anomalies in the region for the 5 year period between surveys, and appears to be a continuation of a trend that began in the mid-1980s. Farther south, however, on the Barnes and Penny ice caps on Baffin Island, this thinning was much more pronounced at over 1 m yr(-1) in the lower elevations. Here temperature anomalies were very small, and the thinning at low elevations far exceeds any associated enhanced ablation. The observations on Barnes, and perhaps Penny, are consistent with the idea that the observed thinning is part of a much longer term deglaciation, as has been previously suggested for Barnes ice cap. On the basis of the regional relationships between elevation and elevation change in our data, the 1995 - 2000 mass balance for the archipelago is estimated to be - 25 km(3) yr(-1) of ice, which corresponds to a sea level increase of 0.064 mm yr(-1). This places it among the more significant sources of eustatic sea level rise, though not as substantial as the Greenland ice sheet, Alaskan glaciers, or the Patagonian ice fields. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, EG&G, Wallops Isl, VA 23337 USA. Geol Survey Canada, Ottawa, ON K1A 0E8, Canada. RP Abdalati, W (reprint author), NASA, Goddard Space Flight Ctr, Mail Code 971, Greenbelt, MD 20771 USA. EM waleed@icesat2.gsfc.nasa.gov; krabill@osb1.wff.nasa.gov; earlb@osb.wff.nasa.gov; manizade@osb.wff.nasa.gov; martin@wasc2.wff.nasa.gov; sonntag@osb.wff.nasa.gov; swift@osb1.wff.nasa.gov; thomas@aim1.wff.nasa.gov; yungel@osb1.wff.nasa.gov; rkoerner@nrcan.gc.ca NR 25 TC 62 Z9 62 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-EARTH JI J. Geophys. Res.-Earth Surf. PD NOV 20 PY 2004 VL 109 IS F4 AR F04007 DI 10.1029/2003JF000045 PG 11 WC Geosciences, Multidisciplinary SC Geology GA 875DS UT WOS:000225400600001 ER PT J AU Kim, SB Lee, T Fukumori, I AF Kim, SB Lee, T Fukumori, I TI The 1997-1999 abrupt change of the upper ocean temperature in the north central Pacific SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID DECADAL CLIMATE VARIABILITY; HEAT-BUDGET; MODEL; ECOSYSTEMS; ANOMALIES; DYNAMICS; AMERICA; FLUX AB The abrupt warming of the north central Pacific Ocean from 1997 to 1999 is studied using an ocean data assimilation product. During this period, the average mixed-layer temperature in the region of 170 - 210 degreesE, 25 - 40 degreesN rises by 1.8 K. The major contributors to the warming are surface heat flux ( 1.3 K), geostrophic advection (0.7 K), and entrainment ( 0.7 K). For the geostrophic advection, the contributions by the zonal, meridional, and vertical components are 0.4, - 0.1 and 0.3 K, respectively. Mixing and meridional Ekman advection have cooling effect. The significance of the geostrophic advection indicates the importance of ocean dynamics in controlling the abrupt warming tendency during the 1997 - 99 period and the inadequacy of a slabmixed-layer model in simulating such warming tendency. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91106 USA. RP Kim, SB (reprint author), CALTECH, Jet Prop Lab, MS 300-323,4800 Oak Grove Dr, Pasadena, CA 91106 USA. EM sk@pacific.jpl.nasa.gov; tlee@pacific.jpl.nasa.gov; if@pacific.jpl.nasa.gov NR 28 TC 20 Z9 20 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 NOV 19 PY 2004 VL 31 IS 22 AR L22304 DI 10.1029/2004GL021142 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 875DM UT WOS:000225399900004 ER PT J AU Navarro-Gonzalez, R Rainey, FA McKay, CP AF Navarro-Gonzalez, R Rainey, FA McKay, CP TI Microbial life in the Atacama Desert - Response SO SCIENCE LA English DT Letter C1 Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Lab Quim Plasmas & Estudios Planetarios, Mexico City 04510, DF, Mexico. Louisiana State Univ, Dept Biol Sci, Baton Rouge, LA 70803 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Navarro-Gonzalez, R (reprint author), Univ Nacl Autonoma Mexico, Inst Ciencias Nucl, Lab Quim Plasmas & Estudios Planetarios, Circuito Exterior,Ciudad Univ,Apartado Postal 70-, Mexico City 04510, DF, Mexico. EM navarro@nuclecu.unam.mx; frainey@lsu.edu; cmckay@mait.arc.nasa.gov RI Gonzalez, Rafael/D-1748-2009; Rainey, Fred/C-8767-2013 OI Rainey, Fred/0000-0001-9129-6844 NR 4 TC 2 Z9 2 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 NOV 19 PY 2004 VL 306 IS 5700 BP 1289 EP 1290 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 873SP UT WOS:000225301600019 ER PT J AU Sprague, AL Boynton, WV Kerry, KE Janes, DM Hunten, DM Kim, KJ Reedy, RC Metzger, AE AF Sprague, AL Boynton, WV Kerry, KE Janes, DM Hunten, DM Kim, KJ Reedy, RC Metzger, AE TI Mars' south polar Ar enhancement: A tracer for south polar seasonal meridional mixing SO SCIENCE LA English DT Article ID GENERAL-CIRCULATION; MARTIAN ATMOSPHERE; SURFACE AB The gamma ray spectrometer on the Mars Odyssey spacecraft measured an enhancement of atmospheric argon over southern high latitudes during autumn followed by dissipation during winter and spring. Argon does not freeze at temperatures normal for southern winter (similar to145 kelvin) and is left in the atmosphere, enriched relative to carbon dioxide (CO2), as the southern seasonal cap of CO2 frost accumulates. Calculations of seasonal transport of argon into and out of southern high latitudes point to meridional (north-south) mixing throughout southern winter and spring. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ New Mexico, Inst Meteorit, Albuquerque, NM 87131 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Sprague, AL (reprint author), Univ Arizona, Lunar & Planetary Lab, 1629 E Univ Blvd, Tucson, AZ 85721 USA. EM sprague@lpl.arizona.edu OI Kim, Kyeong J/0000-0001-6220-8411; Reedy, Robert/0000-0002-2189-1303 NR 20 TC 38 Z9 38 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD NOV 19 PY 2004 VL 306 IS 5700 BP 1364 EP 1367 DI 10.1126/science.1098496 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 873SP UT WOS:000225301600049 PM 15472041 ER PT J AU Grzanka, E Stel'makh, S Gierlotka, S Zhao, Y Palosz, B Palosz, W AF Grzanka, E Stel'makh, S Gierlotka, S Zhao, Y Palosz, B Palosz, W TI Examination of the atomic pair distribution function (PDF) of SiC nanocrystals by in-situ high pressure diffraction SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT Fall Meeting of the European-Materials-Research-Society CY SEP 15-19, 2003 CL WARSAW, POLAND SP European Mat Res Soc DE nanocrystals; silicon carbide; diffraction; high pressure ID X-RAY-DIFFRACTION; HASYLAB; RANGE; ORDER AB X-ray and neutron diffraction experiments were performed on nanocrystalline SiC with the average grain diameters of 7, 12, and 16 nm subjected to isostatic pressure. Under pressure the interatomic distances undergo a complex, non-monotonic changes which were correlated with the compression of the SiC lattice determined from the Bragg scattering. The results indicate the presence of non-uniform distribution of stresses between the interior and surface shell of the nanograins. The present results lend a strong support to the concept of a core-shell model of nanocrystals. (C) 2004 Elsevier B.V. All rights reserved. C1 UNIPRESS, High Pressure Res Ctr, PL-01142 Warsaw, Poland. Univ Warsaw, Inst Expt Phys, PL-00681 Warsaw, Poland. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, George C Marshall Space Flight Ctr, BAE Syst, Huntsville, AL 35812 USA. RP Grzanka, E (reprint author), UNIPRESS, High Pressure Res Ctr, Ul Sokolowska 29-37, PL-01142 Warsaw, Poland. EM elesk@unipress.waw.pl RI Lujan Center, LANL/G-4896-2012 NR 11 TC 3 Z9 3 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD NOV 17 PY 2004 VL 382 IS 1-2 BP 133 EP 137 DI 10.1016/j.jallcom.2004.04.142 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 871SR UT WOS:000225154200022 ER PT J AU Hogrefe, C Lynn, B Civerolo, K Ku, JY Rosenthal, J Rosenzweig, C Goldberg, R Gaffin, S Knowlton, K Kinney, PL AF Hogrefe, C Lynn, B Civerolo, K Ku, JY Rosenthal, J Rosenzweig, C Goldberg, R Gaffin, S Knowlton, K Kinney, PL TI Simulating changes in regional air pollution over the eastern United States due to changes in global and regional climate and emissions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE air quality standards; ozone pollution; regional climate change impacts ID INTERCONTINENTAL TRANSPORT; MODEL EVALUATION; OZONE; URBAN; TEMPERATURE; VARIABILITY; EXPOSURE; METHANE; SUMMER; IMPACT AB [ 1] To simulate ozone (O-3) air quality in future decades over the eastern United States, a modeling system consisting of the NASA Goddard Institute for Space Studies Atmosphere- Ocean Global Climate Model, the Pennsylvania State University/National Center for Atmospheric Research mesoscale regional climate model (MM5), and the Community Multiscale Air Quality model has been applied. Estimates of future emissions of greenhouse gases and ozone precursors are based on the A2 scenario developed by the Intergovernmental Panel on Climate Change (IPCC), one of the scenarios with the highest growth of CO2 among all IPCC scenarios. Simulation results for five summers in the 2020s, 2050s, and 2080s indicate that summertime average daily maximum 8-hour O-3 concentrations increase by 2.7, 4.2, and 5.0 ppb, respectively, as a result of regional climate change alone with respect to five summers in the 1990s. Through additional sensitivity simulations for the five summers in the 2050s the relative impact of changes in regional climate, anthropogenic emissions within the modeling domain, and changed boundary conditions approximating possible changes of global atmospheric composition was investigated. Changed boundary conditions are found to be the largest contributor to changes in predicted summertime average daily maximum 8-hour O-3 concentrations ( 5.0 ppb), followed by the effects of regional climate change ( 4.2 ppb) and the effects of increased anthropogenic emissions (1.3 ppb). However, when changes in the fourth highest summertime 8-hour O-3 concentration are considered, changes in regional climate are the most important contributor to simulated concentration changes (7.6 ppb), followed by the effect of increased anthropogenic emissions (3.9 ppb) and increased boundary conditions (2.8 ppb). Thus, while previous studies have pointed out the potentially important contribution of growing global emissions and intercontinental transport to O3 air quality in the United States for future decades, the results presented here imply that it may be equally important to consider the effects of a changing climate when planning for the future attainment of regional-scale air quality standards such as the U. S. national ambient air quality standard that is based on the fourth highest annual daily maximum 8-hour O-3 concentration. C1 Bur Air Qual Anal & Res, New York State Dept Environm Conservat, Albany, NY 12233 USA. Columbia Univ, Columbia Earth Inst, Ctr Climate Syst Res, New York, NY 10025 USA. SUNY Albany, Atmospher Sci Res Ctr, Albany, NY 12222 USA. Columbia Univ, Mailman Sch Publ Hlth, New York, NY 10032 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Hogrefe, C (reprint author), Bur Air Qual Anal & Res, New York State Dept Environm Conservat, 625 Broadway, Albany, NY 12233 USA. EM chogrefe@dec.state.ny.us RI Kinney, Patrick/H-7914-2012; OI Civerolo, Kevin/0000-0003-1536-2664 NR 49 TC 137 Z9 143 U1 5 U2 31 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 NOV 17 PY 2004 VL 109 IS D22 AR D22301 DI 10.1029/2004JD004690 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 875DO UT WOS:000225400100003 ER PT J AU Xu, K Holubec, KV Love, JE Goodwin, TL Sytkowski, AJ AF Xu, K Holubec, KV Love, JE Goodwin, TL Sytkowski, AJ TI Abnormal erythropoiesis in microgravity. SO BLOOD LA English DT Meeting Abstract CT 46th Annual Meeting of the American-Society-of-Hematology CY DEC 04-07, 2004 CL San Diego, CA SP Amer Soc Hematol C1 Harvard Univ, Sch Med, Lab Cell & Mol Biol, Div Hematol & Oncol,Dept Med,Beth Israel Deacones, Boston, MA USA. Wyle Labs, Houston, TX USA. NASA, Johnson Space Ctr, Cellular Biotechnol Program, Houston, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1900 M STREET. NW SUITE 200, WASHINGTON, DC 20036 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 16 PY 2004 VL 104 IS 11 MA 3701 BP 11B EP 11B PN 2 PG 1 WC Hematology SC Hematology GA 871JO UT WOS:000225127700033 ER PT J AU Jin, ZH Charlock, TP Smith, WL Rutledge, K AF Jin, ZH Charlock, TP Smith, WL Rutledge, K TI A parameterization of ocean surface albedo SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RADIATION AB Measurements at a sea platform show that the ocean surface albedo is highly variable and is sensitive to four physical parameters: solar zenith angle, wind speed, transmission by atmospheric cloud/aerosol, and ocean chlorophyll concentration. Using a validated coupled ocean-atmosphere radiative transfer model, an ocean albedo look up table is created in terms of these four important parameters. A code to read the table is also provided; it gives spectral albedos for a range of oceanic and atmospheric conditions specified by the user. The result is a fast and accurate parameterization of ocean surface albedo for radiative transfer and climate modeling. C1 Analyt Serv & Mat Inc, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23681 USA. RP Jin, ZH (reprint author), Analyt Serv & Mat Inc, Hampton, VA 23666 USA. EM z.jin@larc.nasa.gov NR 11 TC 87 Z9 87 U1 1 U2 11 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 NOV 16 PY 2004 VL 31 IS 22 AR L22301 DI 10.1029/2004GL021180 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 875DJ UT WOS:000225399600005 ER PT J AU Sandwell, D Rosen, P Moore, W Gurrola, E AF Sandwell, D Rosen, P Moore, W Gurrola, E TI Radar interferometry for measuring tidal strains across cracks on Europa SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE crack; Europa; interferometry ID ICE SHELL; TECTONIC PROCESSES; SUBSURFACE OCEAN; RIDGE; TOPOGRAPHY; FEATURES; STRESS; ORIGIN; DRIVEN; CRUST AB A major uncertainty in understanding the interaction between the surface of Europa and its ocean below is the present-day activity of fractures. Using well-constrained models for tidal strain and a force balance in a cracked shell, we estimate the shear and normal displacement of cracks that penetrate upward from the base of the shell. If more than half of the plate is fractured, then surface displacements having amplitudes of 3 to 30 cm will be localized in a band 1 to 100 km from the crack. Plate spreading will occur if more than similar to85% of the plate is fractured. The pattern of deformation is sensitive to both the percentage of plate that is cracked and the total thickness of the shell. Repeat-pass radar interferometry could easily detect and map the activity of the cracks during a short experiment from a variety of suitable orbits with repeating ground tracks. C1 Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, La Jolla, CA 92093 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. RP Sandwell, D (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, Mail Code 0225,9500 Gilman Dr, La Jolla, CA 92093 USA. EM dsandwell@ucsd.edu NR 36 TC 2 Z9 2 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 NOV 16 PY 2004 VL 109 IS E11 AR E11003 DI 10.1029/2004JE002276 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 875DW UT WOS:000225401000001 ER PT J AU Sonwalkar, VS Carpenter, DL Bell, TF Spasojevic, M Inan, US Li, J Chen, X Venkatasubramanian, A Harikumar, J Benson, RF Taylor, WWL Reinisch, BW AF Sonwalkar, VS Carpenter, DL Bell, TF Spasojevic, M Inan, US Li, J Chen, X Venkatasubramanian, A Harikumar, J Benson, RF Taylor, WWL Reinisch, BW TI Diagnostics of magnetospheric electron density and irregularities at altitudes < 5000 km using whistler and Z mode echoes from radio sounding on the IMAGE satellite SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE whistler mode echoes; Z mode echoes; whistler and Z mode wave injection; plasma waves; plasma density irregularities; whistler and Z mode sounding ID AURORAL KILOMETRIC RADIATION; WAVE-INJECTION EXPERIMENTS; SIPLE TRANSMITTER SIGNALS; MAGNETIC-FIELD; DE-1 OBSERVATIONS; PLASMA IMAGER; VLF WAVES; PLASMASPHERIC HISS; TOPSIDE SOUNDERS; SIDE-BAND AB [ 1] When the Radio Plasma Imager (RPI) on the IMAGE satellite operates in the inner plasmasphere and at moderate to low altitudes over the polar regions, pulses emitted at the low end of its 3-kHz to 3-MHz sounding frequency range can propagate in the whistler mode and/or in the Z mode. During soundings with both 25.6-ms pulses and 3.2-ms pulses, whistler mode echoes have been observed in ( 1) "discrete,'' lightning whistler like forms and ( 2) diffuse, widely time spread forms suggestive of mode coupling at the boundaries of density irregularities. Discrete echoes have been observed at altitudes less than approximate to 5000 km both inside the plasmasphere and over the auroral and polar regions, being most common inside the plasmasphere. Diffuse echoes have also been observed at altitudes less than 5000 km, being most common poleward of the plasmasphere. Either discrete or diffuse echoes or both have been detected during one or more soundings on at least half of all IMAGE orbits. In regions poleward of the plasmasphere, diffuse Z mode echoes of a kind reported by Carpenter et al. ( 2003) were found to accompany both discrete and diffuse whistler mode echoes 90% of the time and were also present during 90% of the soundings when no whistler mode echoes were detected. It is proposed that the observed discrete whistler mode echoes are a consequence of RPI signal reflections at the bottom side of the ionosphere and that diffuse whistler mode echoes are a result of scattering of RPI signals by geomagnetic field-aligned electron density irregularities located within 2000 km earthward of the satellite and in directions close to that of the field line passing through IMAGE. Diffuse Z mode echoes are believed to be due to scattering of RPI signals from electron density irregularities within 3000 km of the satellite, particularly those in the generally cross-B direction. Consistent with previous works, our results indicate that the magnetosphere at high latitudes is highly structured, with electron density irregularities that exist over cross-B scales ranging from 10 m to 100 km and that profoundly affect whistler mode propagation. It is demonstrated that both kinds of whistler mode echoes as well as diffuse Z mode echoes have potential for local and remote diagnostics of electron density distributions and structures. C1 Univ Alaska Fairbanks, Dept Elect & Comp Engn, Fairbanks, AK 99775 USA. Stanford Univ, Space Telecommun & Radiosci Lab, Stanford, CA 94305 USA. Los Alamos Natl Lab, Space Data Syst, Los Alamos, NM USA. NASA, Goddard Space Flight Ctr, QSS Grp Inc, Greenbelt, MD 20771 USA. Univ Massachusetts, Ctr Atmospher Res, Lowell, MA 01845 USA. RP Sonwalkar, VS (reprint author), Univ Alaska Fairbanks, Dept Elect & Comp Engn, 306 Tanana Dr,Room 203,Duckering Bldg, Fairbanks, AK 99775 USA. EM ftav@uaf.edu; dlc@nova.stanford.edu; bell@nova.stanford.edu; maria@ssl.berkeley.edu; inan@nova.stanford.edu; fsjl3@uaf.edu; xiangdongc@hotmail.com; ffvss@uaf.edu; jai_harikumar@yahoo.com; robert.f.benson@nasa.gov; taylor@mail630.gsfc.nasa.gov; bodo_reinisch@uml.edu NR 76 TC 19 Z9 19 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-SPACE JI J. Geophys. Res-Space Phys. PD NOV 16 PY 2004 VL 109 IS A11 AR A11212 DI 10.1029/2004JA010471 PG 22 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 875EB UT WOS:000225401600002 ER PT J AU Hansen, J Sato, M AF Hansen, J Sato, M TI Greenhouse gas growth rates SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE climate change; carbon dioxide; methane; fossil fuels ID DEUTERIUM-EXCESS CORRECTION; VOSTOK ICE CORE; CARBON-DIOXIDE; CLIMATE-CHANGE; TEMPERATURE; CO2 AB We posit that feasible reversal of the growth of atmospheric CH4 and other trace gases would provide a vital contribution toward averting dangerous anthropogenic interference with global climate. Such trace gas reductions may allow stabilization of atmospheric CO2 at an achievable level of anthropogenic CO2. emissions, even if the added global warming constituting dangerous anthropogenic interference is as small as 1degreesC. A 1degreesC limit on global warming, with canonical climate sensitivity, requires peak CO2 approximate to 440 ppm if further non-CO2 forcing is +0.5 W/m(2), but peak CO2 approximate to 520 ppm if further non-CO2 forcing is -0.5 W/m(2). The practical result is that a decline of non-CO2 forcings allows climate forcing to be stabilized with a significantly higher transient level of CO2 emissions. Increased "natural" emissions of CO2, N2O and CH4 are expected in response to global warming. These emissions, an indirect effect of all climate forcings, are small compared with human-made climate forcing and occur on a time scale of a few centuries, but they tend to aggravate the task of stabilizing atmospheric composition. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Earth Inst, New York, NY 10025 USA. RP Hansen, J (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM jhansen@giss.nasa.gov NR 26 TC 133 Z9 137 U1 3 U2 40 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 NOV 16 PY 2004 VL 101 IS 46 BP 16109 EP 16114 DI 10.1073/pnas.0406982101 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 872RO UT WOS:000225226200007 PM 15536130 ER PT J AU Vali, H Weiss, B Li, YL Sears, SK Kim, SS Kirschvink, JL Zhang, L AF Vali, H Weiss, B Li, YL Sears, SK Kim, SS Kirschvink, JL Zhang, L TI Formation of tabular single-domain magnetite induced by Geobacter metallireducens GS-15 SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID BIOGENIC MAGNETITE; THERMOPHILIC BACTERIUM; VERWEY TRANSITION; CRYSTAL-GROWTH; IRON; BIOMINERALIZATION; REDUCTION; SEDIMENTS; MINERALIZATION; MAGNETOFOSSILS AB Distinct morphological characteristics of magnetite formed intracellularly by magnetic bacteria (magnetosome) are invoked as compelling evidence for biological activity on Earth and possibly on Mars. Crystals of magnetite produced extracellularly by a variety of bacteria including Geobacter metallireducens GS-15, thermophilic bacteria, and psychrotolerant bacteria are, however, traditionally not thought to have nearly as distinct morphologies. The size and shape of extracellular magnetite depend on the culture conditions and type of bacteria. Under typical CO2-rich culture conditions, GS-15 is known to produce superparamagnetic magnetite (crystal diameters of approximately <30 nm). In the current study, we were able to produce a unique form of tabular, single-domain magnetite under nontraditional (low-CO2) culture conditions. This magnetite has a distinct crystal habit and magnetic properties. This magnetite could be used as a biosignature to recognize ancient biological activities in terrestrial and extraterrestrial environments and also may be a major carrier of the magnetization in natural sediments. C1 McGill Univ, Dept Anat & Cell Biol, Montreal, PQ H3A 2B2, Canada. McGill Univ, Facil Electron Microscopy Res, Montreal, PQ H3A 2B2, Canada. McGill Univ, Dept Earth & Planetary Sci, Montreal, PQ H3A 2A7, Canada. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29803 USA. RP Vali, H (reprint author), McGill Univ, Dept Anat & Cell Biol, 3640 Univ St, Montreal, PQ H3A 2B2, Canada. EM vali@eps.mcgill.ca RI Li, Yiliang/E-9916-2010; Sears, Stephen Kelly/F-3522-2012; Vali, Hojatollah/F-3511-2012 OI Vali, Hojatollah/0000-0003-3464-9943 NR 40 TC 53 Z9 60 U1 3 U2 16 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 NOV 16 PY 2004 VL 101 IS 46 BP 16121 EP 16126 DI 10.1073/pnas.0404040101 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 872RO UT WOS:000225226200009 PM 15525704 ER PT J AU Lemarchand, D Wasserburg, GT Papanastassiou, DA AF Lemarchand, D Wasserburg, GT Papanastassiou, DA TI Rate-controlled calcium isotope fractionation in synthetic calcite SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID CRYSTAL-GROWTH MECHANISMS; PRECIPITATION; ARAGONITE; SEAWATER; CARBONATE; KINETICS; SYSTEM; OXYGEN; MODEL; WATER AB The isotopic composition of Ca (Delta(44)Ca/Ca-40) in calcite crystals has been determined relative to that in the parent solutions by TIMS using a double spike. Solutions were exposed to an atmosphere of NH3 and CO2, provided by the decomposition of (NH4)(2)CO3, following the procedure developed by previous workers. Alkalinity, pH and concentrations of CO32-, HCO3-, and CO2 in solution were determined. The procedures permitted us to determine Delta(Ca-44/Ca-40) over a range of pH conditions, with the associated ranges of alkalinity. Two solutions with greatly different Ca concentrations were used, but, in all cases, the condition [Ca2+] >> [CO32-] was met. A wide range in Delta(Ca-44/Ca-40) was found for the calcite crystals, extending from 0.04 +/- 0.13parts per thousand to -1.34 +/- 0.15parts per thousand, generally anti-correlating with the amount of Ca removed from the solution. The results show that Delta(Ca-44/Ca-40) is a linear function of the saturation state of the solution with respect to calcite (Omega). The two parameters are very well correlated over a wide range in Omega for each solution with a given [Ca]. The linear correlation extended from Delta(Ca-44/Ca-40) = -1.34 +/- 0.15parts per thousand to 0.04 +/- 0.13parts per thousand, with the slopes directly dependent on [Ca]. Solutions, which were vigorously stirred, showed a much smaller range in Delta(Ca-44/Ca-40) and gave values of -0.42 +/- 0.14parts per thousand, with the largest effect at low Omega. It is concluded that the diffusive flow of CO32- into the immediate neighborhood of the crystal-solution interface is the rate-controlling mechanism and that diffusive transport of Ca2+ is not a significant factor. The data are simply explained by the assumptions that: a) the immediate interface of the crystal and the solution is at equilibrium with Delta(Ca-44/Ca-40) similar to -1.5 +/- 0.25parts per thousand; and b) diffusive inflow of CO32- causes supersaturation, thus precipitating Ca from the regions exterior to the narrow zone of equilibrium. The result is that Delta(Ca-44/Ca-40) is a monotonically increasing (from negative values to zero) function of Omega. We consider this model to-be-a plausible explanation of most of the available data reported in the literature. The well-resolved but small and regular isotope fractionation shifts in Ca are thus not related to the diffusion of very large hydrated Ca complexes, but rather due to the ready availability of Ca in the general neighborhood of the crystal-solution interface. The largest isotopic shift which occurs as a small equilibrium effect is then subdued by supersaturation precipitation for solutions where [Ca2+] >> [CO32-] + [HCO3-]. It is shown that there is a clear temperature dependence of the net isotopic shifts that is simply due to changes in Omega due to the equilibrium "constants" dependence on temperature, which changes the degree of saturation and hence the amount of isotopically unequilibrated Ca precipitated. The effects that are found in natural samples, therefore, will be dependent on the degree of diffusive inflow of carbonate species at or around the crystal-liquid interface in the particular precipitating system, thus limiting the equilibrium effect. Copyright (C) 2004 Elsevier Ltd C1 CALTECH, Div Geol & Planetary Sci, Lunat Asylum, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. RP Lemarchand, D (reprint author), Ecole & Observ Sci Terre, Ctr Geochim Surface, 1 Rue Blessig, F-67084 Strasbourg, France. EM lemarcha@illite.u-strasbg.fr NR 33 TC 131 Z9 138 U1 4 U2 37 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD NOV 15 PY 2004 VL 68 IS 22 BP 4665 EP 4678 DI 10.1016/j.gca.2004.05.029 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 869JU UT WOS:000224980000011 ER PT J AU Yang, FL Lau, KM AF Yang, FL Lau, KM TI Trend and variability of China precipitation in spring and summer: Linkage to sea-surface temperatures SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE East Asian monsoon; precipitation; sea-surface temperature; interannual and interdecadal variability ID SINGULAR-VALUE DECOMPOSITION; 500 HPA HEIGHT; ASIAN MONSOON; INTERDECADAL VARIABILITY; SOUTHERN OSCILLATION; INDIAN MONSOON; EAST-ASIA; EL-NINO; CLIMATE; ENSO AB Observational records in the past 50 years show an upward trend of boreal-summer precipitation over central eastern China and a downward trend over northern China. During boreal spring, the trend is upward over southeastern China and downward over central eastern China. This study explores the forcing mechanism of these trends in association with the global sea-surface temperature (SST) variations on the interannual and interdecadal time scales. Results based on singular value decomposition (SVD) analyses show that the interannual variability of China precipitation in boreal spring and summer can be well defined by two centres of action for each season, which are covarying with two interannual modes of SSTs. The first SVD modes of precipitation in spring and summer, which are centred in southeastern China and northern China respectively, are linked to an El Nino-southern oscillation (ENSO)-like mode of SSTs. The second SVD modes of precipitation in both seasons are confined to central eastern China, and are primarily linked to SST variations over the warm pool and the Indian Ocean. Features of the anomalous 850 hPa winds and 700 hPa geopotential height corresponding to these modes support a physical mechanism that explains the causal links between the modal variations of precipitation and SSTs. On the decadal and longer time scale, similar causal links are found between the same modes of precipitation and SSTs, except for the case of springtime precipitation over central eastern China. For this case, while the interannual mode of precipitation is positively correlated with the interannual variations of SSTs over the warm pool and Indian Ocean, the interdecadal mode is negatively correlated with a different SST mode, i.e. the North Pacific mode. The latter is responsible for the observed downward trend of springtime precipitation over central eastern China. For all other cases, both the interannual and interdecadal variations of precipitation can be explained by the same mode of SSTs. The upward trend of springtime precipitation over southeastern China and downward trend of summertime precipitation over northern China are attributable to the warming trend of the ENSO-like mode. The recent frequent summertime floods over central eastern China are linked to the warming trend of SSTs over the warm pool and Indian Ocean. Copyright (C) 2004 Royal Meteorological Society. C1 NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, GEST,UMBC, Greenbelt, MD 20771 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, Code 913, Greenbelt, MD 20771 USA. EM fyang@climate.gsfc.nasa.gov RI Lau, William /E-1510-2012; Yang, Fanglin/A-1948-2013 OI Lau, William /0000-0002-3587-3691; NR 41 TC 127 Z9 153 U1 5 U2 38 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0899-8418 J9 INT J CLIMATOL JI Int. J. Climatol. PD NOV 15 PY 2004 VL 24 IS 13 BP 1625 EP 1644 DI 10.1002/joc.1094 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 873NB UT WOS:000225286000003 ER PT J AU Evans, JP Smith, RB Oglesby, RJ AF Evans, JP Smith, RB Oglesby, RJ TI Middle East climate simulation and dominant precipitation processes SO INTERNATIONAL JOURNAL OF CLIMATOLOGY LA English DT Article DE Middle East; climate; precipitation; regional climate model ID MODEL SIMULATIONS; UNITED-STATES; ISRAEL; SEA; ATMOSPHERE; AUSTRALIA; SCENARIOS; PATTERNS; RAINFALL; SYSTEM AB The ability of both the ECMWF-TOGA analyses and regional model RegCM2 to simulate the climate of the Middle East is examined. The climate of the region displays high spatial, seasonal and interannual variability, providing a strong test of a climate model's abilities. The higher resolution of RegCM2, compared with the ECMWF analyses, allows it to capture the spatial variability of temperature and precipitation better despite model biases being present. Both RegCM2 and the analyses have a cold bias, exacerbated in RegCM2 by a bias present in the prescribed sea-surface-temperature forcing. RegCM2 does not capture the annual cycle of precipitation on the Black and Caspian Sea coasts, where very steep topography exists, nor on the eastern Mediterranean coast, where the coastal mountains are not resolved. RegCM2 does capture the seasonal cycle in the Fertile Crescent and Zagros Mountains, where it is strongly influenced by a plateau circulation above the Iranian plateau. It is shown that accurate simulation of precipitation in these regions requires the correct simulation of storm tracks, topographic interactions and atmospheric stability. RegCM2 is better able to simulate the interannual variability averaged over the entire domain compared with the ECMWF analyses; however, they both have difficulty reproducing the interannual variability in particular subregions. It is also shown that processes controlling the seasonality of precipitation differ in different subregions and are often different from the processes controlling interannual variability. This suggests that, in order to model precipitation successfully, a horizontal scale that allows differentiation of precipitation zones dominated by different precipitation processes, both seasonally and interannually, is required. Copyright (C) 2004 Royal Meteorological Society. C1 Yale Univ, Dept Geol & Geophys, New Haven, CT 06520 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Yale Univ, Dept Geol & Geophys, POB 208109, New Haven, CT 06520 USA. EM jason.evans@yale.edu RI Evans, Jason/F-3716-2011 OI Evans, Jason/0000-0003-1776-3429 NR 42 TC 77 Z9 80 U1 2 U2 7 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0899-8418 EI 1097-0088 J9 INT J CLIMATOL JI Int. J. Climatol. PD NOV 15 PY 2004 VL 24 IS 13 BP 1671 EP 1694 DI 10.1002/joc.1084 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 873NB UT WOS:000225286000006 ER PT J AU Langhoff, PW Boatz, JA Hinde, RJ Sheehy, JA AF Langhoff, PW Boatz, JA Hinde, RJ Sheehy, JA TI Atomic spectral methods for molecular electronic structure calculations SO JOURNAL OF CHEMICAL PHYSICS LA English DT Review ID ADAPTED PERTURBATION-THEORY; POTENTIAL-ENERGY SURFACES; DENSITY-FUNCTIONAL THEORY; DER-WAALS COMPLEXES; DEFORMED ATOMS; QUANTUM-THEORY; CONICAL INTERSECTIONS; 3-BODY NONADDITIVITY; GENERAL THEORY; DIATOMICS AB Theoretical methods are reported for ab initio calculations of the adiabatic (Born-Oppenheimer) electronic wave functions and potential energy surfaces of molecules and other atomic aggregates. An outer product of complete sets of atomic eigenstates familiar from perturbation-theoretical treatments of long-range interactions is employed as a representational basis without prior enforcement of aggregate wave function antisymmetry. The nature and attributes of this atomic spectral-product basis are indicated, completeness proofs for representation of antisymmetric states provided, convergence of Schrodinger eigenstates in the basis established, and strategies for computational implemention of the theory described. A diabaticlike Hamiltonian matrix representative is obtained, which is additive in atomic-energy and pairwise-atomic interaction-energy matrices, providing a basis for molecular calculations in terms of the (Coulombic) interactions of the atomic constituents. The spectral-product basis is shown to contain the totally antisymmetric irreducible representation of the symmetric group of aggregate electron coordinate permutations once and only once, but to also span other (non-Pauli) symmetric group representations known to contain unphysical discrete states and associated continua in which the physically significant Schrodinger eigenstates are generally embedded. These unphysical representations are avoided by isolating the physical block of the Hamiltonian matrix with a unitary transformation obtained from the metric matrix of the explicitly antisymmetrized spectral-product basis. A formal proof of convergence is given in the limit of spectral closure to wave functions and energy surfaces obtained employing conventional prior antisymmetrization, but determined without repeated calculations of Hamiltonian matrix elements as integrals over explicitly antisymmetric aggregate basis states. Computational implementations of the theory employ efficient recursive methods which avoid explicit construction the metric matrix and do not require storage of the full Hamiltonian matrix to isolate the antisymmetric subspace of the spectral-product representation. Calculations of the lowest-lying singlet and triplet electronic states of the covalent electron pair bond (H-2) illustrate the various theorems devised and demonstrate the degree of convergence achieved to values obtained employing conventional prior antisymmetrization. Concluding remarks place the atomic spectral-product development in the context of currently employed approaches for ab initio construction of adiabatic electronic eigenfunctions and potential energy surfaces, provide comparisons with earlier related approaches, and indicate prospects for more general applications of the method. (C) 2004 American Institute of Physics. C1 Univ Calif, San Diego Supercomp Ctr, La Jolla, CA 92093 USA. USAF, Res Lab, PRS, Propuls Sci Div, Edwards AFB, CA USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NASA, George C Marshall Space Flight Ctr, Propuls Res Ctr TD 40, Huntsville, AL 35812 USA. RP Langhoff, PW (reprint author), Univ Calif, San Diego Supercomp Ctr, La Jolla, CA 92093 USA. EM langhoff@drifter.sdsc.edu OI Hinde, Robert/0000-0003-3499-9222 NR 117 TC 4 Z9 4 U1 0 U2 6 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 15 PY 2004 VL 121 IS 19 BP 9323 EP 9342 DI 10.1063/1.1794634 PG 20 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 868DT UT WOS:000224895000013 PM 15538852 ER PT J AU Ranson, KJ Sun, G Kharuk, VI Kovacs, K AF Ranson, KJ Sun, G Kharuk, VI Kovacs, K TI Assessing tundra-taiga boundary with multi-sensor satellite data SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE tundra-taiqa transition zone; landsat; ETM; MISR; MODIS; RADARSAT; multi-spectral; multi-angle; temporal; boreal forest ID LAND-COVER CHANGE; CLIMATE SYSTEM; FOREST-TUNDRA; BOREAL FOREST; VEGETATION; ECOSYSTEMS; COMPONENTS; IMAGERY; RUSSIA; AREA AB Monitoring the dynamics of the circumpolar boreal forest (taiga) and Arctic tundra boundary is important for understanding the causes and consequences of changes observed in these areas. This ecotone, the world's largest, stretches for over 13,400 km and marks the transition between the northern limits of forests and the Southern margin of the tundra. Because of the inaccessibility and large extent of this zone, remote sensing data can play an important role for mapping the characteristics and monitoring the dynamics. Basic understanding of the capabilities of existing space borne instruments for these purposes is required. In this study we examined the use of several remote sensing techniques for characterizing the existing tundra-taiga ecotone. These include Landsat-7, MISR, MODIS and RADARSAT data. Historical cover maps, recent forest stand measurements and high-resolution IKONOS images were used for local ground truth. It was found that a tundra-taiga transitional area can be characterized using multi-spectral Landsat ETM+ summer images, multi-angle MISR red band reflectance images, RADARSAT images with larger incidence angle, or multi-temporal and multi-spectral MODIS data. Because of different resolutions and spectral regions covered, the transition zone maps derived from different data types were not identical, but the general patterns were consistent. (C) 2004 Published by Elsevier Inc. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Univ Maryland, Dept Geog, College Pk, MD 20742 USA. Academogorodok, VN Sukachev Inst Forest, Krasnoyarsk, Russia. Sci Syst & Applicat Inc, Lanham, MD USA. RP Ranson, KJ (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. EM kenneth.j.ranson@nasa.gov; guoqing@taiga.gsfc.nasa.gov; kharuk@forest.akedem.ru; kkovacs@forest.gsfc.nasa.gov RI Ranson, Kenneth/G-2446-2012 OI Ranson, Kenneth/0000-0003-3806-7270 NR 38 TC 29 Z9 32 U1 0 U2 11 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 NOV 15 PY 2004 VL 93 IS 3 BP 283 EP 295 DI 10.1016/j.rse.2004.06.019 PG 13 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 864QT UT WOS:000224648700001 ER PT J AU Pereira, JMC Mota, B Privette, JL Caylor, KK Silva, JMN Sa, ACL Ni-Meister, W AF Pereira, JMC Mota, B Privette, JL Caylor, KK Silva, JMN Sa, ACL Ni-Meister, W TI A simulation analysis of the detectability of understory burns in miombo woodlands SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE simulation analysis; understory burns; miombo woodlands ID INITIATIVE SAFARI 2000; BIDIRECTIONAL REFLECTANCE; VEGETATION FIRE; CANOPY; MODEL; FORESTS; AREA; PRODUCTS; KALAHARI; BIOMASS AB The miombo woodlands of southern Africa are one of the most extensively burned biomes in the tropics. The detectability of understory burns in these woodlands was assessed with a sensitivity analysis approach, based on a hybrid geometrical-optical radiative transfer model. Model input data were obtained from a variety of sources, including field biometry and spectroradiometry, and satellite data. The effects of variable tree percent cover, leaf area index, stand density, burn scar age, illumination and observation geometry, and spectral region, were taken into account. Detectability of understory burns was defined as the spectral separability of burned and unburned understory, measured with the Jeffries-Matusita distance, for all possible combinations of the green, red, and near-infrared channels of the Moderate Resolution Imaging Spectrometer (MODIS) sensor. Single channels, or pairwise combinations of channels perform poorly at detecting understory burns, but a large improvement in detectability is obtained for the combination of the three spectral domains. The detectability of understory burns is largely insensitive to the effects of stand structure and illumination/observation geometry, and depends primarily on burn scar age. Our results agree with those of previous satellite-based studies of burns scar detectability in African savanna woodlands. (C) 2004 Elsevier Inc. All rights reserved. C1 Inst Super Agron, Dept Forestry, P-1349017 Lisbon, Portugal. Trop Res Inst, Cartog Ctr, P-1300142 Lisbon, Portugal. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Princeton Univ, Dept Civil & Environm Engn, Princeton, NJ 08544 USA. CUNY Hunter Coll, Dept Geog, New York, NY 10021 USA. RP Inst Super Agron, Dept Forestry, Tapada Ajuda, P-1349017 Lisbon, Portugal. EM jmcpereira@isa.utl.pt; bmota@isa.utl.pt; jeff.privette@gsfc.nasa.gov; kcaylor@princeton.edu; joaosilva@isa.utl.pt; anasa@isa.utl.pt; wenge@geo.hunter.cuny.edu RI Caylor, Kelly/B-7734-2008; Privette, Jeffrey/G-7807-2011; Pereira, Jose/I-1283-2014; Silva, Joao/C-5673-2013 OI Caylor, Kelly/0000-0002-6466-6448; Privette, Jeffrey/0000-0001-8267-9894; Pereira, Jose/0000-0003-2583-3669; Silva, Joao/0000-0001-5201-9836 NR 44 TC 22 Z9 23 U1 2 U2 6 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 NOV 15 PY 2004 VL 93 IS 3 BP 296 EP 310 DI 10.1016/j.rse.2004.01.009 PG 15 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 864QT UT WOS:000224648700002 ER PT J AU Smrekar, SE McGill, GE Raymond, CA Dimitriou, AM AF Smrekar, SE McGill, GE Raymond, CA Dimitriou, AM TI Geologic evolution of the Martian dichotomy in the Ismenius area of Mars and implications for plains magnetization SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Mars; dichotomy; crustal magnetism; gravity; isostasy; faulting; gravitational relaxation; extension ID CRUSTAL DICHOTOMY; HEMISPHERIC DICHOTOMY; INTERNAL STRUCTURE; MANTLE CONVECTION; PHASE-TRANSITIONS; CRATERED TERRAIN; PLATE-TECTONICS; GIANT IMPACT; FIELD; TOPOGRAPHY AB [1] The origin of the Martian dichotomy, which divides highlands from lowlands, is unknown. We examine a section of the dichotomy ( 50 - 90E) defined by steep scarps and normal faults. Stratigraphy and age relationships preclude the formation of the 2.5 km high boundary via erosion. The abrupt disappearance of topographic knobs similar to 300 - 500 km to the northeast is interpreted as a buried fault. Alignment of the buried fault with grabens, stratigraphy, and age determinations using crater counts indicate that the lowland bench is down faulted highlands crust. The estimated local strain (3.5%) and fault pattern are broadly consistent with gravitational relaxation of a plateau boundary. Magnetic and gravity anomalies occur on either side of the buried fault. Admittance analysis indicates isostatic compensation. Although nonunique, a model with a 10 km thick intracrustal block under the lowland bench, a 20 km thick block under the plains, and an excess density of 200 kg/m(3) provides a good fit to the isostatic anomaly. A good fit to a profile of the magnetic field perpendicular to the dichotomy is produced using uniformly polarized intracrustal blocks 10 - 20 km thick, an intensity of 6 Am/m, a field inclination of - 30degrees, and gaps aligned with the isostatic anomalies. One interpretation is that high-density intrusions demagnetized the crust after dynamo cessation and that low-lying magnetized areas could be down faulted highlands crust. Another model ( inclination of 30degrees) has magnetized crust beneath the isostatic anomalies, separated by gaps. The gaps could result from hydrothermal alteration of the crust along fault zones. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Massachusetts, Dept Geosci, Amherst, MA 01003 USA. SLR Alaska, Anchorage, AK 99503 USA. RP Smrekar, SE (reprint author), CALTECH, Jet Prop Lab, Mail Stop 183-501,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ssmrekar@jpl.nasa.gov NR 87 TC 16 Z9 16 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 NOV 13 PY 2004 VL 109 IS E11 AR E11002 DI 10.1029/2004JE002260 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 872ES UT WOS:000225191100001 ER PT J AU Diaz, A AF Diaz, A TI The future of NASA SO SCIENCE LA English DT Letter C1 NASA, Washington, DC 20546 USA. RP Diaz, A (reprint author), NASA, 300 E St SW, Washington, DC 20546 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 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 NOV 12 PY 2004 VL 306 IS 5699 BP 1133 EP 1133 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 872FM UT WOS:000225193100018 PM 15539584 ER PT J AU Gaddy, GA Locke, EP Miller, ME Broughton, R Albrecht-Schmitt, TE Mills, G AF Gaddy, GA Locke, EP Miller, ME Broughton, R Albrecht-Schmitt, TE Mills, G TI Photoinduced, controlled generation of palladium crystallite structures in polyimide films SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SMALL GOLD CRYSTALLITES; OPTICAL-PROPERTIES; POLYMER GELS; NANOPARTICLES; PHOTOGENERATION; PARTICLES; COMPLEXES; METALS AB Structures of Pd crystallites with nanometer dimensions are formed on the surface of and inside polyimide films by a combination of photochemical and thermal processes. Photoinduced transformations of polyamic acid films containing Pd2+ complexes prior to thermal curing affect the subsequent thermal imidization of the polymer and reduction of the remaining palladium ions. The extent of photolysis controls the formation and characteristics of surface and subsurface metallic layers as well as the sizes of Pd particles generated within and below the interlayer region. Interference between waves reflected from the continuous embedded Pd layer and waves reflected from the continuous surface metal layer is the origin of the colors observed in photolyzed and cured films. Multicolored areas are a result of nanometer range variations of the interlayer distance. Optical properties typical of Fabry-Perot filters are observed when the thickness of the surface layer and internal metal layer are similar. The etalon-like films experience significant reversible dimensional changes upon exposure to white light. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Auburn Univ, Dept Biol Sci, Auburn, AL 36849 USA. Auburn Univ, Dept Text Engn, Auburn, AL 36849 USA. Auburn Univ, Dept Chem, Auburn, AL 36849 USA. RP Gaddy, GA (reprint author), USA, Res Lab, Sensors & Electron Devices Directorate, Adelphi, MD 20783 USA. EM greg.gaddy@us.army.mil; elocke@kandmenviromental.com; millsge@auburn.edu NR 36 TC 9 Z9 9 U1 1 U2 5 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 NOV 11 PY 2004 VL 108 IS 45 BP 17378 EP 17383 DI 10.1021/jp0479421 PG 6 WC Chemistry, Physical SC Chemistry GA 869OM UT WOS:000224993900018 ER PT J AU Wachter, S Patel, SK Kouveliotou, C Bouchet, P Feryal, O Tennant, AF Woods, PM Hurley, K Becker, W Slane, P AF Wachter, S Patel, SK Kouveliotou, C Bouchet, P Feryal, O Tennant, AF Woods, PM Hurley, K Becker, W Slane, P TI Precise localization of the soft gamma repeater SGR 1627-41 and the anomalous X-ray pulsar AXP 1E1841-045 with Chandra SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; infrared : stars; stars : individual (1E 1841-045, SAX J1635.8-4736, SGR 1627-41); stars : neutron; X-rays : stars ID MAGNETIZED NEUTRON-STARS; SUPERNOVA REMNANT G27.4+0.0; NEAR-INFRARED COUNTERPART; TELESCOPE OBSERVATIONS; OPTICAL COUNTERPART; 1E 2259+586; DISCOVERY; DISTANCE; 2MASS; SEARCH AB We present precise localizations of AXP 1E1841-045 and SGR 1627-41 with Chandra. We obtained new infrared observations of SGR 1627-41 and reanalyzed archival observations of AXP 1E1841-045 in order to refine their positions and search for infrared counterparts. A faint source is detected inside the error circle of AXP 1E1841-045. In the case of SGR 1627-41, several sources are located within the error radius of the X-ray position, and we discuss the likelihood of one of them being the counterpart. We compare the properties of our candidates to those of other known anomalous X-ray pulsar (AXP) and soft gamma repeater (SGR) counterparts. We find that the counterpart candidates for SGR 1627-41 and SGR 1806-20 would have to be intrinsically much brighter than AXPs in order to have counterparts detectable with the observational limits currently available for these sources. To confirm the reported counterpart of SGR 1806-20, we obtained new infrared observations during the 2003 July burst activation of the source. No brightening of the suggested counterpart is detected, implying that the counterpart of SGR 1806-20 remains yet to be identified. C1 CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Univ Space Res Assoc, NSSTC, Huntsville, AL 35805 USA. NASA, George C Marshall Space Flight Ctr, NSSTC, Huntsville, AL 35805 USA. Natl Opt Astron Observ, Cerro Tololo Interamer Observ, La Serena, Chile. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP CALTECH, Spitzer Sci Ctr, MS 220-6, Pasadena, CA 91125 USA. EM wachter@ipac.caltech.edu; Sandeep.Patel@msfc.nasa.gov; chryssa.kouveliotou@msfc.nasa.gov NR 63 TC 34 Z9 34 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 NOV 10 PY 2004 VL 615 IS 2 BP 887 EP 896 DI 10.1086/424704 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 870GT UT WOS:000225046300030 ER PT J AU Becker, W Weisskopf, MC Arzoumanian, Z Lorimer, D Camilo, F Elsner, RF Kanbach, G Reimer, O Swartz, DA Tennant, AF O'Dell, SL AF Becker, W Weisskopf, MC Arzoumanian, Z Lorimer, D Camilo, F Elsner, RF Kanbach, G Reimer, O Swartz, DA Tennant, AF O'Dell, SL TI A multiwavelength search for a counterpart of the brightest unidentified gamma-ray source 3EG J2020+4017 (2CG 078+2) SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (G78.2+2.1); X-rays : individual (RX J2020.2+4026) ID MEDIUM-SENSITIVITY SURVEY; YOUNG RADIO PULSAR; X-RAY; SUPERNOVA REMNANT; EGRET SOURCES; GALACTIC PLANE; PSR J2021+3651; J1835+5918; DISCOVERY; CYGNI AB In search of the counterpart to the brightest unidentified gamma-ray source, 3EG J2020+4017 (2CG 078+2), we report on new X-ray and radio observations of the gamma Cygni field with the Chandra X-Ray Observatory and with the Green Bank Telescope (GBT). We also report on reanalysis of archival ROSAT data. With Chandra it became possible for the first time to measure the position of the putative gamma-ray counterpart, RX J2020.2+4026, with subarcsecond accuracy and to deduce its X-ray spectral characteristics. These observations demonstrate that RX J2020.2+4026 is associated with a K field star and therefore is unlikely to be the counterpart of the bright gamma-ray source 2CG 078+2 in the SNR G78.2+2.1 as had been previously suggested. The Chandra observation detected 37 additional X-ray sources, which were correlated with catalogs of optical and infrared data. Subsequent GBT radio observations covered the complete 99% EGRET likelihood contour of 3EG J2020+4017 with a sensitivity limit of L-820 approximate to 0.1 mJy kpc(2), which is lower than most of the recent deep radio search limits. If there is a pulsar operating in 3EG J2020+4017, this sensitivity limit suggests that either the pulsar does not produce significant amounts of radio emission or that its geometry is such that the radio beam does not intersect with the line of sight. Finally, reanalysis of archival ROSAT data leads to a flux upper limit of f(X)(0.1-2.4 keV) < 1.8 x 10(13) ergs s(-1) cm(-2) for a putative pointlike X-ray source located within the 68% confidence contour of 3EG J2020+4017. Adopting the supernova remnant age of 5400 yr and assuming a spin-down to X-ray energy conversion factor of 10(-4), this upper limit constrains the parameters of a putative neutron star as a counterpart for 3EG J2020+4017 to be P &GSIM; 160 (d 1.5 kpc)(-1) ms, P &GSIM; 5 x 10(-13) (d 1.5 kpc(-1))(-1) s s(-1), and B-&BOTTOM; &GSIM; 9 x 10(12) (d 1.5 kpc)(-1) G. C1 Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. NASA, Dept Space Sci, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NASA, USRA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Manchester, Jodrell Bank Observ, Macclesfield SK11 9DL, Cheshire, England. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. Ruhr Univ Bochum, D-44780 Bochum, Germany. NASA, USRA, Dept Space Sci, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Becker, W (reprint author), Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. RI Reimer, Olaf/A-3117-2013; OI Reimer, Olaf/0000-0001-6953-1385; O'Dell, Stephen/0000-0002-1868-8056 NR 51 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 NOV 10 PY 2004 VL 615 IS 2 BP 897 EP 907 DI 10.1086/424563 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 870GT UT WOS:000225046300031 ER PT J AU Becker, W Weisskopf, MC Tennant, AF Jessner, A Dyks, J Harding, AK Zhang, SN AF Becker, W Weisskopf, MC Tennant, AF Jessner, A Dyks, J Harding, AK Zhang, SN TI Revealing the X-ray emission processes of old rotation-powered pulsars: XMM-Newton observations of PSR B0950+08, PSR B0823+26, and PSR J2043+2740 SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : general; pulsars : individual (PSR B0823+26, PSR B0950+08, PSR J2043+2740); stars : neutron; stars : rotation; X-rays : stars ID RADIATION PAIR FRONTS; POLAR-CAP; GAMMA-RAY; NEUTRON-STAR; MILLISECOND PULSARS; EMPIRICAL-THEORY; CRAB PULSAR; DEATH LINES; GEOMETRY; SURFACE AB We have completed part of a program to study the X-ray emission properties of old rotation-powered pulsars with XMM-Newton in order to probe and identify the origin of their X-radiation. The X-ray emission from these old pulsars is largely dominated by nonthermal processes. None of the observed spectra required adding a thermal component consisting of either a hot polar cap or surface cooling emission to model the data. The X-ray spectrum of PSR B0950+08 is best described by a single power law of photon index alpha = 1.93(-0.12)(+0.14) Taking optical data from the VLT FORS1 into account, a broken power-law model with the break point E(break) = 0.67(-0.41)(+0.18) keV and the photon indices alpha(1) = 1.27-0.01+0.02 and alpha(2) = 1.88-0.11+0.14 for E < E(break) and E > E(break), respectively, is found to describe the pulsar's broadband spectrum from the optical to the X-ray band. Three sigma temperature upper limits for possible contributions from a heated polar cap or the whole neutron star surface are T(pc)(infinity) < 0.87 x 10(6) and T(s)(infinity) < 0.48 x 10(6) K, respectively. We also find that the X-ray emission from PSR B0950+08 is pulsed with two peaks per rotation period. The phase separation between the two X-ray peaks is similar to 144 degrees (maximum to maximum), which is similar to the pulse peak separation observed in the radio band at 1.4 GHz. The main radio peak and the trailing X-ray peak are almost phase-aligned. The fraction of X-ray pulsed photons is similar to 30%. A phase-resolved spectral analysis confirms the nonthermal nature of the pulsed emission and finds no spectral variations as a function of pulse phase. Detailed pulse profile simulations using the polar gap, the outer gap, and the two-pole caustic model constrain the pulsar's emission geometry to be that of an almost orthogonal rotator, for which the two-pole caustic model can reproduce the observed doubly peaked X-ray pulse profile. The spectral emission properties observed for PSR B0823+26 are similar to those of PSR B0950+08. Its energy spectrum is very well described by a single power law with photon index alpha = 2.5(-0.45)(+0.9). Three sigma temperature upper limits for thermal contributions from a hot polar cap or from the entire neutron star surface are T(pc)(infinity) < 1.17 x 10(6) and T(s)(infinity) < 0.5 x 10(6) K, respectively. There is evidence for pulsed X-ray emission at the similar to 97% confidence level with a pulsed fraction of 49%+/- 22%. For PSR J2043+2740, which is located similar to 1 degrees outside the boundary of the Cygnus Loop, we report the first detection of X-ray emission. A power-law spectrum or a combination of a thermal and a power-law spectrum both yield acceptable descriptions of its X-ray spectrum. No X-ray pulses are detected from PSR J2043+2740 and the sensitivity is low-the 2 sigma pulsed fraction upper limit is 57% assuming a sinusoidal pulse profile. C1 Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. NASA, Dept Space Sci, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Max Planck Inst Radioastron, D-53902 Bad Munstereifel, Germany. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RP Becker, W (reprint author), Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. RI Harding, Alice/D-3160-2012 NR 68 TC 41 Z9 41 U1 0 U2 2 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 NOV 10 PY 2004 VL 615 IS 2 BP 908 EP 920 DI 10.1086/424498 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 870GT UT WOS:000225046300032 ER PT J AU Bonev, BP Mumma, MJ Dello Russo, N Gibb, EL DiSanti, MA Magee-Sauer, K AF Bonev, BP Mumma, MJ Dello Russo, N Gibb, EL DiSanti, MA Magee-Sauer, K TI Infrared OH prompt emission as a proxy of water production in comets: Quantitative analysis of the multiplet near 3046 cm(-1) in comets C/1999 H1 (Lee) and C/2001 A2 (LINEAR) SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : general; comets : individual (C/2001 A2); comets : individual (Lee (C/1999 H1)); infrared : solar system ID O1 HALE-BOPP; CARBON-MONOXIDE; B2 HYAKUTAKE; OXYGEN LINES; SPECTRUM; METHANE; PHOTODISSOCIATION; 153P/IKEYA-ZHANG; RELEASE; NIRSPEC AB We report quantitative measurements of OH vibrational prompt emission in comets C/1999 H1 ( Lee) and C/2001 A2 ( LINEAR) based on high-dispersion infrared spectra acquired at the Keck Observatory atop Mauna Kea, Hawaii. Effective g-factors for four OH lines near 3046 cm(-1) (in the 1-0 band) were obtained from simultaneous detections of OH and H2O. The measured spatial distribution of this OH "quadruplet'' traces that of H2O, as expected if the excited OH is produced directly by water photolysis. These results establish OH prompt emission as an alternative (and convenient) proxy for water in comets. Possible limitations to the approach are discussed. Extension to other OH multiplets in the L band will permit direct comparison with theoretical models for the rotational population distribution of the free OH radicals produced by H2O photolysis in cometary atmospheres. C1 NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Toledo, Dept Phys & Astron, Ritter Astrophys Res Ctr, Toledo, OH 43606 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Rowan Univ, Dept Chem & Phys, Glassboro, NJ 08028 USA. RP Bonev, BP (reprint author), NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Code 693, Greenbelt, MD 20771 USA. EM bbonev@lepvax.gsfc.nasa.gov RI mumma, michael/I-2764-2013; Magee-Sauer, Karen/K-6061-2015; Dello Russo, Neil/G-2727-2015 OI Magee-Sauer, Karen/0000-0002-4979-9875; Dello Russo, Neil/0000-0002-8379-7304 NR 35 TC 18 Z9 18 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 NOV 10 PY 2004 VL 615 IS 2 BP 1048 EP 1053 DI 10.1086/424587 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 870GT UT WOS:000225046300044 ER PT J AU Harker, DE Wooden, DH Woodward, CE Lisse, CM AF Harker, DE Wooden, DH Woodward, CE Lisse, CM TI Grain properties of comet C/1995 O1 (Hale-Bopp) (vol 580, pg 579, 2002) SO ASTROPHYSICAL JOURNAL LA English DT Correction C1 Univ Calif San Diego, Ctr Astrophys & Space Sci, San Diego, CA 92103 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Univ Minnesota, Dept Astron, Minneapolis, MN 55455 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Harker, DE (reprint author), Univ Calif San Diego, Ctr Astrophys & Space Sci, San Diego, CA 92103 USA. RI Lisse, Carey/B-7772-2016 OI Lisse, Carey/0000-0002-9548-1526 NR 1 TC 22 Z9 22 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 NOV 10 PY 2004 VL 615 IS 2 BP 1081 EP 1081 DI 10.1086/424592 PN 1 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 870GT UT WOS:000225046300048 ER PT J AU Gudipati, MS Allamandola, LJ AF Gudipati, MS Allamandola, LJ TI Polycyclic aromatic hydrocarbon ionization energy lowering in water ices SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : clouds; methods : laboratory; molecular processes; radiation mechanisms : nonthermal; ultraviolet : ISM; ultraviolet : solar system ID GAS-GRAIN CHEMISTRY; ASTROPHYSICAL ICES; FACILE GENERATION; MOLECULAR CLOUDS; MATRIX-ISOLATION; LIQUID WATER; AMINO-ACIDS; INTERSTELLAR; ANALOGS; SPECTROSCOPY AB In studying various interstellar and solar system ice analogs, we have recently found that upon vacuum ultraviolet photolysis, polycyclic aromatic hydrocarbons ( PAHs) frozen in water ice at low temperatures are easily ionized and indefinitely stabilized as trapped ions ( Gudipati; Gudipati & Allamandola). Here we report the first experimental study that shows that PAH ionization energy is significantly lowered in PAH/H(2)O ices, in agreement with recent theoretical work ( Woon & Park). The ionization energy ( IE) of the PAH studied here, quaterrylene (C(40)H(20), IE = 6.11 eV), is lowered by up to 2.11 eV in water ice. PAH ionization energy reduction in low- temperature water ice substantially expands the astronomical regions in which trapped ions and electrons may be important. This reduction in ionization energy should also hold for other types of trapped species in water-rich interstellar, circumstellar, and solar system ices. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Univ Cologne, Inst Phys Chem, D-5000 Cologne, Germany. RP Gudipati, MS (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM gudipati@ipst.umd.edu; louis.j.allamandola@nasa.gov RI Gudipati, Murthy/F-7575-2011 NR 26 TC 29 Z9 29 U1 2 U2 19 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 NOV 10 PY 2004 VL 615 IS 2 BP L177 EP L180 DI 10.1086/426392 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 870GW UT WOS:000225046600029 ER PT J AU Hwang, U Laming, JM Badenes, C Berendse, F Blondin, J Cioffi, D DeLaney, T Dewey, D Fesen, R Flanagan, KA Fryer, CL Ghavamian, P Hughes, JP Morse, JA Plucinsky, PP Petre, R Pohl, M Rudnick, L Sankrit, R Slane, PO Smith, RK Vink, J Warren, JS AF Hwang, U Laming, JM Badenes, C Berendse, F Blondin, J Cioffi, D DeLaney, T Dewey, D Fesen, R Flanagan, KA Fryer, CL Ghavamian, P Hughes, JP Morse, JA Plucinsky, PP Petre, R Pohl, M Rudnick, L Sankrit, R Slane, PO Smith, RK Vink, J Warren, JS TI A million second Chandra view of Cassiopeia A SO ASTROPHYSICAL JOURNAL LA English DT Article DE supernova remnants; supernovae : general; X-rays : individual (Cassiopeia A); X-rays : ISM ID GAMMA-RAY BURSTS; X-RAY; CAS-A; EXPANSION; COLLAPSE; EJECTA; CORE; NUCLEOSYNTHESIS; PROGENITORS; SUPERNOVAE AB We introduce a million second observation of the supernova remnant Cassiopeia A with the Chandra X-Ray Observatory. The bipolar structure of the Si-rich ejecta (northeast jet and southwest counterpart) is clearly evident in the new images, and their chemical similarity is confirmed by their spectra. These are most likely due to jets of ejecta as opposed to cavities in the circumstellar medium, since we can reject simple models for the latter. The properties of these jets and the Fe-rich ejecta will provide clues to the explosion of Cas A. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, College Pk, MD 20742 USA. USN, Res Lab, Washington, DC 20375 USA. Inst Estudis Espacials Catalunya, E-08034 Barcelona, Spain. USN, Res Lab, Washington, DC 20375 USA. N Carolina State Univ, Raleigh, NC 27695 USA. George Washington Univ, Washington, DC 20052 USA. Univ Minnesota, Minneapolis, MN 55455 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Dartmouth Coll, Hanover, NH 03755 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Rutgers State Univ, Piscataway, NJ 08854 USA. Arizona State Univ, Tempe, AZ 85287 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Iowa State Univ, Ames, IA 50011 USA. SRON, Natl Inst Space Res, NL-3584 CA Utrecht, Netherlands. RP Hwang, U (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. EM hwang@milkyway.gsfc.nasa.gov; jlaming@ssd5.nrl.navy.mil; badenes@ieec.fcr.es; fberendse@ssd5.nrl.navy.mil; john_blondin@ncsu.edu; professor@cioffi.us; tdelaney@astro.umn.edu; dd@space.mit.edu; fesen@snr.dartmouth.edu; kaf@space.mit.edu; fryer@lanl.gov; parviz@pha.jhu.edu; jackph@physics.rutgers.edu; jon.morse@asu.edu; plucinsk@head.cfa.harvard.edu; rob@milkyway.gsfc.nasa.gov; mkp@iastate.edu; larry@astro.umn.edu; ravi@pha.jhu.edu; slane@head.cfa.harvard.edu; rsmith@milkyway.gsfc.nasa.gov; j.vink@sron.nl; jesawyer@physics.rutgers.edu NR 29 TC 117 Z9 118 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 NOV 10 PY 2004 VL 615 IS 2 BP L117 EP L120 DI 10.1086/426186 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 870GW UT WOS:000225046600014 ER PT J AU Lin, JR Zhang, SN AF Lin, JR Zhang, SN TI Radio pulsars as progenitors of anomalous X-ray pulsars and soft gamma-ray repeaters: Magnetic field evolution through pulsar glitches SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : general; pulsars : individual (Crab pulsar, PSR B1757-24, Vela Pulsar) ID SUPERNOVA REMNANT G5.4-1.2; NEUTRON-STARS; PSR B1757-24; ORIGIN; AGE AB Glitches are common phenomena in pulsars. After each glitch, there is often a permanent increase in the pulsar's spin- down rate. Therefore, a pulsar's present spin- down rate may be much higher than its initial value and the characteristic age of a pulsar based on its present spin- down rate and period may be shorter than its true age. At the same time, the permanent increase of its spin- down rate implies that the pulsar's surface magnetic field is increased after each glitch. Consequently, after many glitches some radio pulsars may evolve into magnetars, i. e., strongly magnetized and slowly rotating neutron stars. C1 Tsing Hua Univ, Dept Phys, Beijing 100084, Peoples R China. Tsing Hua Univ, Ctr Astrophys, Beijing 100084, Peoples R China. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NASA, Space Sci Lab, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China. RP Lin, JR (reprint author), Tsing Hua Univ, Dept Phys, Beijing 100084, Peoples R China. NR 31 TC 22 Z9 23 U1 2 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 NOV 10 PY 2004 VL 615 IS 2 BP L133 EP L136 DI 10.1086/426316 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 870GW UT WOS:000225046600018 ER PT J AU Share, GH Murphy, RJ Smith, DM Schwartz, RA Lin, RP AF Share, GH Murphy, RJ Smith, DM Schwartz, RA Lin, RP TI Rhessi e(+)-e(-) annihilation radiation observations: Implications for conditions in the flaring solar chromosphere SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : chromosphere; Sun : flares; Sun : particle emission; Sun : X-rays, gamma rays ID PARTICLE-ACCELERATION; FLARES; LINE; IONIZATION; POSITRONS; EMISSION; IONS AB RHESSI has measured the positron- electron annihilation line and continuum in three solar flares: 2002 July 23, 2003 October 28, and 2003 November 2. The 511 keV line was broad (similar to 4 - 8 keV) in all three flares, consistent with annihilations in an ambient ionized medium at temperatures above 10(5) K. The measured continuum from positronium and from Compton scattering was unobservable, with the exception of the first 4 minutes of the October 28 flare observation; this indicates that the density at which most annihilations occurred was greater than similar to 10(14) H cm(-3). The width of the line narrowed in 2 minutes to similar to1 keV late in the October 28 flare, consistent with annihilation in ionized H < K and &GE; 10(15) cm(-3). There is evidence for a similar decrease in line width late in the November 2 flare. These observations suggest a highly dynamic flaring atmosphere at chromospheric densities that can reach transition- region temperatures, then cool to less than 10(4) K in minutes while remaining highly ionized. Although the energy contained in high- energy accelerated particles may have been enough to heat the plasma, the rate of deposition is not correlated with the temperature determined by the 511 keV line width, and this raises questions about the energy source. C1 USN, EO Hulburt Ctr Space Res, Res Lab, Washington, DC 20375 USA. Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. Univ Calif Santa Cruz, Santa Cruz Inst Particle Phys, Santa Cruz, CA 95064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Share, GH (reprint author), USN, EO Hulburt Ctr Space Res, Res Lab, Washington, DC 20375 USA. EM gerald.share@nrl.navy.mil; ronald.murphy@nrl.navy.mil; dsmith@scipp.ucsc.edu; richard.schwartz@gsfc.nasa.gov; rlin@ssl.berkeley.edu NR 24 TC 35 Z9 35 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 NOV 10 PY 2004 VL 615 IS 2 BP L169 EP L172 DI 10.1086/426478 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 870GW UT WOS:000225046600027 ER PT J AU Street, KW Hill, CM Philipp, WH Tanner, SP Gorse, J Lusk, AL Taylor, JR Dickens, JE AF Street, KW Hill, CM Philipp, WH Tanner, SP Gorse, J Lusk, AL Taylor, JR Dickens, JE TI Properties of a novel ion-exchange film SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID SOLID-PHASE SPECTROPHOTOMETRY; REMOVAL AB A new ion-exchange material [based on poly(acrylic acid)] and some of its analytical applications have been reported. This paper contains data on the ion-exchange properties of the film form of the material and its potential application to the decontamination of wastewater and drinking water. The film has a high exchange capacity of 5-6 mequiv/g and a pK(a) of 5.7. The calcium form is the most effective for removing metal ions from solution, and the optimum pH range is between 5 and 7. The exchange rates are slower for the film form than for the bead and powder forms of the ion-exchange material; otherwise, the properties are similar. The film is effective when hard water solutions are employed and also when metal ions are in the complex matrix of wastewater from electroplating. The film can be used in flow systems having a flow channel large enough to allow passage of turbid solutions. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ W Florida, Dept Chem, Pensacola, FL 32514 USA. Baldwin Wallace Coll, Dept Chem, Berea, OH 44017 USA. RP Street, KW (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM Kenneth.W.Street@nasa.gov NR 16 TC 5 Z9 5 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD NOV 10 PY 2004 VL 43 IS 23 BP 7600 EP 7607 DI 10.1021/ie0207535 PG 8 WC Engineering, Chemical SC Engineering GA 869IW UT WOS:000224977600043 ER PT J AU Zheng, QN Shen, SSP Yuan, YL Huang, NE Klemas, V Yan, XH Shi, FY Zhang, XB Zhao, ZX Li, XF Clemente-Colon, P AF Zheng, QN Shen, SSP Yuan, YL Huang, NE Klemas, V Yan, XH Shi, FY Zhang, XB Zhao, ZX Li, XF Clemente-Colon, P TI Evidence of the coexistence of upstream and downstream solitary wavetrains in the real atmosphere SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID APERTURE-RADAR IMAGE; COASTAL LEE WAVES; STRATIFIED FLOW; SAR IMAGES; TOPOGRAPHY; SPACE AB From a true colour image of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) onboard the Orbview-2 satellite, we observed two packets of orderly wave clouds on two sides of Hainan Island in the South China Sea. A packet of 23 wave clouds stretches southward from the island. A second packet of more than 20 wave clouds stretches north-eastward off the north-east coast of the island. The concave orientation of the wave cloud lines implies that both packets are propagating away from the island. A chart of geopotential height and velocity at 850 mbar shows a south-westerly air flow over the island; hence the two wave cloud packets propagate upstream and downstream, simultaneously. Thus, we have found new evidence of the coexistence of both upstream and downstream solitary wavetrains generated in the real atmosphere by land topographic disturbances. Comparison with theoretical results supports this conclusion. C1 Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. Univ Alberta, Dept Math Sci, Edmonton, AB T6G 2E1, Canada. SOA, Inst Oceanog 1, Qingdao, Shandong, Peoples R China. NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD 29771 USA. Univ Delaware, Dept Civil Engn, Ctr Appl Coastal Res, Newark, DE 19716 USA. NOAA, NESDIS, Camp Springs, MD 20746 USA. RP Zheng, QN (reprint author), Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. EM quanan@atmos.umd.edu RI Zheng, Quanan/F-9025-2010; Clemente-Colon, Pablo/F-5581-2010; Zhao, Zhongxiang/A-1918-2012; Li, Xiaofeng/B-6524-2008 OI Li, Xiaofeng/0000-0001-7038-5119 NR 18 TC 5 Z9 5 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 NOV 10 PY 2004 VL 25 IS 21 BP 4433 EP 4440 DI 10.1080/01431160310001609716 PG 8 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 873ZY UT WOS:000225321900001 ER PT J AU Ho, CR Zheng, Q Kuo, NJ Tsai, CH Huang, NE AF Ho, CR Zheng, Q Kuo, NJ Tsai, CH Huang, NE TI Observation of the kuroshio intrusion region in the south china sea from AVHRR data SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID ALTIMETER DATA; PACIFIC; WATER; OCEAN AB The variability of sea surface temperature in the region of the Kuroshio intrusion into the South China Sea (SCS) through the Luzon Strait was studied using sea surface temperature (SST) derived from Advanced Very High Resolution Radiometer (AVHRR) from 1985 to 2002. The covariance empirical orthogonal function (CEOF) method was applied for analysing the temporal and spatial variability in the study area. The results show that the Kuroshio intrusion during El Nino periods is weaker than that in La Nina periods. The calculation of surface layer heat of the Kuroshio intrusion region also shows response to the El Nino-La Nina events. The variation is attributed to the changes in wind fields during those events. C1 Natl Taiwan Ocean Univ, Dept Oceanog, Chilung 20243, Taiwan. Univ Delaware, Coll Marine Studies, Newark, DE USA. NASA, Goddard Space Flight Ctr, Oceans & Ice Branch, Greenbelt, MD USA. RP Ho, CR (reprint author), Natl Taiwan Ocean Univ, Dept Oceanog, Chilung 20243, Taiwan. EM chungru@sun4.oce.ntou.edu.tw RI Zheng, Quanan/F-9025-2010 NR 21 TC 23 Z9 25 U1 0 U2 5 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 NOV 10 PY 2004 VL 25 IS 21 BP 4583 EP 4591 DI 10.1080/0143116042000192376 PG 9 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 873ZY UT WOS:000225321900010 ER PT J AU Gatski, TB Wallin, S AF Gatski, TB Wallin, S TI Extending the weak-equilibrium condition for algebraic Reynolds stress models to rotating and curved flows SO JOURNAL OF FLUID MECHANICS LA English DT Article ID NONLINEAR EDDY-VISCOSITY; TURBULENCE MODELS; EXPLICIT; INVARIANCE AB Weis & Hutter (J. Fluid Mech. vol. 476, 2003, p. 63) obtained an implicit algebraic Reynolds stress model from a differential Reynolds stress transport equation valid in an arbitrarily rotating time-dependent coordinate frame (relative to an inertial system). Although the form of this implicit algebraic equation differed from previous implicit forms, its correctness was argued based on the objective tensor form of the implicit algebraic equation. It is shown here that such conclusions based on simple coordinate frame transformations are incomplete, and that additional considerations taking into account flow rotation and curvature, for example, are necessary. By properly accounting for both the arbitrary motions of the observer coordinate frame as well as the motion of the flow itself, it is shown that previous formulations and application of the weak-equilibrium condition are correct in contrast to the results of Weis Hutter. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Swedish Def Res Agcy, SE-17290 Stockholm, Sweden. RP Gatski, TB (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 22 TC 26 Z9 27 U1 0 U2 2 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 NOV 10 PY 2004 VL 518 BP 147 EP 155 DI 10.1017/SS0022112004000837 PG 9 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 874FF UT WOS:000225335600006 ER PT J AU Kwok, R AF Kwok, R TI Annual cycles of multiyear sea ice coverage of the Arctic Ocean: 1999-2003 SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE multiyear sea ice; annual cycles; Arctic Ocean ID PASSIVE MICROWAVE ALGORITHMS; VOLUME PRODUCTION; BEAUFORT SEA; APRIL 1997; AREA; BALANCE AB [1] For the years 1999 - 2003, we estimate the time-varying perennial ice zone (PIZ) coverage and construct the annual cycles of multiyear ( MY, including second year) ice coverage of the Arctic Ocean using QuikSCAT backscatter, MY fractions from RADARSAT, and the record of ice export from satellite passive microwave observations. An area balance approach extends the winter MY coverage from QuikSCAT to the remainder of the year. From these estimates, the coverage of MY ice at the beginning of each year is 3774 x 10(3) km(2) (2000), 3896 x 10(3) km(2) (2001), 4475 x 10(3) km(2) (2002), and 4122 x 10(3) km(2) (2003). Uncertainties in coverage are similar to 150 x 10(3) km(2). In the mean, on 1 January, MY ice covers similar to 60% of the Arctic Ocean. Ice export reduces this coverage to similar to 55% by 1 May. From the multiple annual cycles, the area of first-year (FY) ice that survives the intervening summers are 1192 x 10(3) km(2) (2000), 1509 x 10(3) km(2) (2001), and 582 x 10(3) km(2) (2002). In order for the MY coverage to remain constant from year to year, these replenishment areas must balance the overall area export and melt during the summer. The effect of the record minimum in Arctic sea ice area during the summer of 2002 is seen in the lowest area of surviving FY ice of the three summers. In addition to the spatial coverage, the location of the PIZ is important. One consequence of the unusual location of the PIZ at the end of the summer of 2002 is the preconditioning for enhanced export of MY ice into the Barents and Kara seas. Differences between the minimums in summer sea ice coverage from our estimates and passive microwave observations are discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kwok, R (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ron.kwok@jpl.nasa.gov RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 23 TC 43 Z9 43 U1 0 U2 16 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 NOV 10 PY 2004 VL 109 IS C11 AR C11004 DI 10.1029/2003JC002238 PG 13 WC Oceanography SC Oceanography GA 872EP UT WOS:000225190800002 ER PT J AU Krymskii, AM Ness, NF Crider, DH Breus, TK Acuna, MH Hinson, DP AF Krymskii, AM Ness, NF Crider, DH Breus, TK Acuna, MH Hinson, DP TI Solar wind interaction with the ionosphere/atmosphere and crustal magnetic fields at Mars: Mars Global Surveyor Magnetometer/Electron Reflectometer, radio science, and accelerometer data SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE Mars; magnetic fields; ionosphere; plasma convection; atmosphere ID ELECTRON-DENSITY PROFILES; UPPER-ATMOSPHERE; MARTIAN IONOSPHERE; MGS ACCELEROMETER; THERMAL TIDES; AEROBRAKING AB [ 1] The solar wind ( SW) mainly interacts with the Martian ionosphere/atmosphere. However, the intense crustal magnetization creates localized minimagnetospheres above the surface. The interplanetary magnetic field ( IMF) can reconnect with these crustal fields and this allows SW and more energetic particles to precipitate into and heat the neutral atmosphere in localized regions, especially in the southern hemisphere. A study of 907 electron density profiles obtained by the MGS Radio Science (RS) experiment at latitudes from + 63degrees to + 77degrees and 219 profiles at latitudes -69degrees to -64.5degrees has been conducted. The role of the magnetic field as a driving force of the cross-terminator convection is discussed. Longitudinal variations of neutral atmosphere scale height H-peak derived from the MGS RS data have been analyzed. Ionospheric parameters are found to be more variable in the southern than in the northern hemisphere. This correlates well with the variability of the magnetic field direction from local zenith. The scale height of neutral atmosphere density H-ACC derived from the MGS accelerometer data is also found to be more variable in the southern than in the northern hemisphere. C1 Rostov State Univ, Dept Astrophys, Rostov Na Donu 344104, Russia. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. Amer Hist Assoc, Washington, DC 20064 USA. Russian Acad Sci, Space Res Inst, IKI, Moscow 117997, Russia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA. RP Krymskii, AM (reprint author), Rostov State Univ, Dept Astrophys, Ul Zorge 5, Rostov Na Donu 344104, Russia. EM amkrym@yahoo.com; nfness@udel.edu; dcrider@lepvax.gsfc.nasa.gov; breus@iki.rssi.ru; mario.acuna@gsfc.nasa.gov; hinson@nimbus.stanford.edu RI Hurley, Dana/F-4488-2015 OI Hurley, Dana/0000-0003-1052-1494 NR 22 TC 29 Z9 30 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-SPACE JI J. Geophys. Res-Space Phys. PD NOV 10 PY 2004 VL 109 IS A11 AR A11306 DI 10.1029/2004JA010420 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 872EV UT WOS:000225191400003 ER PT J AU Schwanke, RW Lutz, RR AF Schwanke, RW Lutz, RR TI Experience with the architectural design of a modest product family SO SOFTWARE-PRACTICE & EXPERIENCE LA English DT Article DE software product family; software architecture; software product line; medical image analysis; modest product family; product line architecture AB Many product families are modest in the sense that they consist of a sequence of incremental products with, at any point in time, only a few distinct products available and minimal variations among the products. Such product families, nevertheless, are often large, complex systems, widely deployed, and possessing stringent safety and performance requirements. This paper describes a case study that tends to confirm the value of using a product-line approach for the architectural design of a modest product family. The paper describes the process, design alternatives, and lessons learned, both positive and negative, from the architectural design of one such family of medical image analysis products. Realized benefits included identifying previously unrecognized common behavior and sets of features that were likely to change together, aligning the architecture with specific market needs and with the organization, and reducing unplanned dependencies. Most interesting were the unanticipated benefits, including decoupling the product-family architecture from the order of implementation of features, and using the product-family architecture as a 'guiding star' with subsequent releases moving toward, rather than away from, the planned architecture. Copyright (C) 2004 John Wiley Sons, Ltd. C1 Iowa State Univ Sci & Technol, Dept Comp Sci, Ames, IA 50011 USA. Siemens Corp Res Inst, Princeton, NJ 08540 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Iowa State Univ Sci & Technol, Dept Comp Sci, 226 Atanasoff Hall, Ames, IA 50011 USA. EM rlutz@cs.iastate.edu NR 25 TC 5 Z9 5 U1 0 U2 1 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0038-0644 EI 1097-024X J9 SOFTWARE PRACT EXPER JI Softw.-Pract. Exp. PD NOV 10 PY 2004 VL 34 IS 13 BP 1273 EP 1296 DI 10.1002/spe.613 PG 24 WC Computer Science, Software Engineering SC Computer Science GA 867VD UT WOS:000224869700004 ER PT J AU Battistuzzi, FU Feijao, A Hedges, SB AF Battistuzzi, FU Feijao, A Hedges, SB TI A genomic timescale of prokaryote evolution: insights into the origin of methanogenesis, phototrophy, and the colonization of land SO BMC EVOLUTIONARY BIOLOGY LA English DT Review ID HORIZONTAL GENE-TRANSFER; DETERMINING DIVERGENCE TIMES; BILLION YEARS AGO; METHANOPYRUS-KANDLERI; PHYLOGENETIC ANALYSIS; OXYGENIC PHOTOSYNTHESIS; MAXIMUM-LIKELIHOOD; MAJOR BACTERIAL; PROTEIN CLOCK; EARLY-LIFE AB Background: The timescale of prokaryote evolution has been difficult to reconstruct because of a limited fossil record and complexities associated with molecular clocks and deep divergences. However, the relatively large number of genome sequences currently available has provided a better opportunity to control for potential biases such as horizontal gene transfer and rate differences among lineages. We assembled a data set of sequences from 32 proteins (similar to 7600 amino acids) common to 72 species and estimated phylogenetic relationships and divergence times with a local clock method. Results: Our phylogenetic results support most of the currently recognized higher-level groupings of prokaryotes. Of particular interest is a well-supported group of three major lineages of eubacteria ( Actinobacteria, Deinococcus, and Cyanobacteria) that we call Terrabacteria and associate with an early colonization of land. Divergence time estimates for the major groups of eubacteria are between 2.5 - 3.2 billion years ago (Ga) while those for archaebacteria are mostly between 3.1 - 4.1 Ga. The time estimates suggest a Hadean origin of life ( prior to 4.1 Ga), an early origin of methanogenesis (3.8 - 4.1 Ga), an origin of anaerobic methanotrophy after 3.1 Ga, an origin of phototrophy prior to 3.2 Ga, an early colonization of land 2.8 - 3.1 Ga, and an origin of aerobic methanotrophy 2.5 - 2.8 Ga. Conclusions: Our early time estimates for methanogenesis support the consideration of methane, in addition to carbon dioxide, as a greenhouse gas responsible for the early warming of the Earths' surface. Our divergence times for the origin of anaerobic methanotrophy are compatible with highly depleted carbon isotopic values found in rocks dated 2.8 - 2.6 Ga. An early origin of phototrophy is consistent with the earliest bacterial mats and structures identified as stromatolites, but a 2.6 Ga origin of cyanobacteria suggests that those Archean structures, if biologically produced, were made by anoxygenic photosynthesizers. The resistance to desiccation of Terrabacteria and their elaboration of photoprotective compounds suggests that the common ancestor of this group inhabited land. If true, then oxygenic photosynthesis may owe its origin to terrestrial adaptations. C1 Penn State Univ, NASA, Astrobiol Inst, University Pk, PA 16802 USA. Penn State Univ, Dept Biol, University Pk, PA 16802 USA. European Mol Biol Lab, D-69117 Heidelberg, Germany. RP Hedges, SB (reprint author), Penn State Univ, NASA, Astrobiol Inst, 208 Mueller Lab, University Pk, PA 16802 USA. EM fxb142@psu.edu; feijao@embl.de; sbh1@psu.edu NR 100 TC 211 Z9 227 U1 4 U2 77 PU BIOMED CENTRAL LTD PI LONDON PA 236 GRAYS INN RD, FLOOR 6, LONDON WC1X 8HL, ENGLAND SN 1471-2148 J9 BMC EVOL BIOL JI BMC Evol. Biol. PD NOV 9 PY 2004 VL 4 AR 44 DI 10.1186/1471-2148-4-44 PG 14 WC Evolutionary Biology; Genetics & Heredity SC Evolutionary Biology; Genetics & Heredity GA 885EU UT WOS:000226140700001 PM 15535883 ER PT J AU McFarquhar, GM Platnick, S Di Girolamo, L Wang, HK Wind, G Zhao, GY AF McFarquhar, GM Platnick, S Di Girolamo, L Wang, HK Wind, G Zhao, GY TI Trade wind cumuli statistics in clean and polluted air over the Indian Ocean from in situ and remote sensing measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BOUNDARY-LAYER STRUCTURE; FRACTIONAL CLOUDINESS; INDOEX; MICROPHYSICS; RETRIEVAL; AEROSOLS; CLIMATE AB Relationships between trade wind cumuli coverage and aerosol concentration N-a, and between cloud optical thickness tau(c) and N-a are examined using in situ and remote sensing observations acquired on 4 days within and downwind of the Indo-Asian haze. Cloud top height and cloud coverage decrease as N-a increases, whereas tc increases, which could be due to aerosol or meteorological effects. Clouds with horizontal sizes less than 2 km, neglected in prior studies, contribute up to 40% to cloud area, and must be considered in studies of aerosol indirect and semi-direct effects. When radiative transfer models are applied to the observations, a regional change in top of the atmosphere TOA (surface) 0.64 mm radiative forcing of approximately +6 (+7) W m(-2) mum(-1) associated with changes in cloud properties is found. To the degree that synoptic-scale forcings do not vary systematically as air flows south, the results may be interpreted as the dominance of semi-direct over indirect forcing within the Indo-Asian haze for the times sampled. C1 Univ Illinois, Dept Atmospher Sci, Urbana, IL 61801 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 21114 USA. Govt Serv Inc, Commun L3, Vienna, VA 22180 USA. RP McFarquhar, GM (reprint author), Univ Illinois, Dept Atmospher Sci, 105 S Gregory St, Urbana, IL 61801 USA. EM mcfarq@atmos.uiuc.edu RI Wang, Hailong/B-8061-2010; Platnick, Steven/J-9982-2014; OI Wang, Hailong/0000-0002-1994-4402; Platnick, Steven/0000-0003-3964-3567; McFarquhar, Greg/0000-0003-0950-0135 NR 13 TC 16 Z9 16 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 NOV 9 PY 2004 VL 31 IS 21 AR L21105 DI 10.1029/2004GL020412 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 872EF UT WOS:000225189800001 ER PT J AU Newman, PA Kawa, SR Nash, ER AF Newman, PA Kawa, SR Nash, ER TI On the size of the Antarctic ozone hole SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID POLAR VORTEX; CHLORINE; STRATOSPHERE; CLIMATE; AEROSOL AB Aprimary estimate of the severity of the Antarctic ozone hole is its size. The size is calculated from the area contained by total column ozone values less than 220 Dobson Units (DU) during September-October. The 220-DU value is used because it is lower than pre-1980 observed ozone values, and because it is in the strong ozone gradient region. We quantitatively show that the ozone hole size is primarily sensitive to effective stratospheric chlorine trends, and secondarily to the year-to-year variations in temperatures near the edge of the polar vortex. Temperatures are in turn sensitive to variations in tropospheric planetary wave forcing of the Southern Hemisphere stratosphere. Currently the average hole size reaches approximately 25 million km(2) each spring. Slow decreases of ozone depleting substances will only result in a decrease of about 1 million km(2) by 2015. This slow size decrease will be obscured by large dynamically forced year-to-year variations of 4 million km(2) (1sigma), and possibly delayed by greenhouse gas cooling of the Antarctic stratosphere. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. RP Newman, PA (reprint author), NASA, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA. EM Paul.A.Newman@nasa.gov RI Newman, Paul/D-6208-2012; Kawa, Stephan/E-9040-2012 OI Newman, Paul/0000-0003-1139-2508; NR 20 TC 43 Z9 44 U1 1 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 NOV 9 PY 2004 VL 31 IS 21 AR L21104 DI 10.1029/2004GL020596 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 872EF UT WOS:000225189800003 ER PT J AU Williams, BP Fritts, DC Wang, L She, CY Vance, JD Schmidlin, FJ Goldberg, RA Mullemann, A Lubken, FJ AF Williams, BP Fritts, DC Wang, L She, CY Vance, JD Schmidlin, FJ Goldberg, RA Mullemann, A Lubken, FJ TI Gravity waves in the arctic mesosphere during the MaCWAVE/MIDAS summer rocket program SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MIDDLE ATMOSPHERE; DYNAMICS; RADAR AB The MaCWAVE/MIDAS rocket campaign occurred at the Andoya Rocket Range (69 degreesN, 16 degreesE) on July 1 - 2 and 4 - 5, 2002. This paper investigates gravity waves in the mesosphere using falling spheres dropped from rockets and the Weber sodium lidar at the ALOMAR observatory. The vertical displacement of a sodium sporadic layer on July 5 showed great variability at periods from minutes to hours with an observed frequency spectral slope of - 1.89. The 2 salvos had similar wave amplitudes at the mesopause, whereas Salvo 2 had stronger amplitudes in the lower atmosphere. The dominant wave period varied strongly with height, possibly due to wave breaking on the strong mean gradients or oblique propagation of wave packets. One long-period wave appeared to propagate vertically from 75 - 95 km with a reduction of its vertical wavelength consistent with the mean wind gradient, but it is unclear whether it was a single wave or a superposition of waves. C1 NW Res Associates Inc, Boulder, CO 80301 USA. Colorado State Univ, Dept Phys, Ft Collins, CO 80523 USA. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Atmospher Phys, D-18225 Kuhlungsborn, Germany. RP Williams, BP (reprint author), NW Res Associates Inc, 3380 Mitchell Lane, Boulder, CO 80301 USA. EM biff@cora.nwra.com RI Goldberg, Richard /E-1881-2012 NR 14 TC 16 Z9 16 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 NOV 9 PY 2004 VL 31 IS 24 AR L24S05 DI 10.1029/2004GL020049 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 872EK UT WOS:000225190300001 ER PT J AU Byrne, S Ivanov, AB AF Byrne, S Ivanov, AB TI Internal structure of the Martian south polar layered deposits SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE ice; Mars; stratigraphy ID ORBITER LASER ALTIMETER; NORTHERN ICE CAP; MARS; FLOW; SURFACE; REGIONS; SUBLIMATION; TOPOGRAPHY; ALBEDO; ACCUMULATION AB [ 1] We investigate the three-dimensional (3-D) stratigraphic structure of the south polar layered deposits (SPLD) on Mars. Prominent bench-forming layers exposed on SPLD scarps were observed and mapped in three dimensions using high-resolution topographic and imaging data sets. Using the 3-D location of exposures of one of these strata, we can accurately describe the shape of that layer using simple mathematical functions. Analysis of these functions and the surface topography can be used to reliably predict where on other scarps this layer is exposed. In general this bench-forming layer ( and its surrounding strata) is not flat and is well approximated as a parabolic dome near the center of the SPLD. Its curvature indicates that when deposited it was draped over a topographic dome similar in size to that of the present day. The scarps in which this layer is exposed must have formed subsequently and have not been significantly modified by flow processes. The basement topography exercises some control over the shape of the interior strata in extreme cases. Our successful layer-fitting technique illustrates the regional uniformity in layer formation and the lack of major internal defects ( such as faulting) within the SPLD. We have mapped exposures of what appear to be this layer in scarps farther from the center of the deposits. The position of these exposures can be used to modify the modeled parabolic shape at the periphery of the SPLD. These peripheral elevations provide constraints on the role of flow in the overall shaping of the SPLD. C1 MIT, Dept Earth & Planetary Sci, Cambridge, MA 02139 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP MIT, Dept Earth & Planetary Sci, 77 Massachusetts Ave,Room 54-510, Cambridge, MA 02139 USA. EM shane@quake.mit.edu; abi@mipl.jpl.nasa.gov RI Byrne, Shane/B-8104-2012; Ivanov, Anton/C-8944-2014 OI Ivanov, Anton/0000-0001-8376-8581 NR 59 TC 14 Z9 14 U1 2 U2 3 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 NOV 9 PY 2004 VL 109 IS E11 AR E11001 DI 10.1029/2004JE002267 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 872ER UT WOS:000225191000001 ER PT J AU Norabuena, E Dixon, TH Schwartz, S DeShon, H Newman, A Protti, M Gonzalez, V Dorman, L Flueh, ER Lundgren, P Pollitz, F Sampson, D AF Norabuena, E Dixon, TH Schwartz, S DeShon, H Newman, A Protti, M Gonzalez, V Dorman, L Flueh, ER Lundgren, P Pollitz, F Sampson, D TI Geodetic and seismic constraints on some seismogenic zone processes in Costa Rica SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Review DE seismogenic zone; Costa Rica; geodetic and seismic ID MIDDLE AMERICA TRENCH; NICARAGUA TSUNAMI EARTHQUAKE; CASCADIA SUBDUCTION ZONE; CURRENT PLATE MOTIONS; NAZCA-SOUTH AMERICA; SAN-ANDREAS FAULT; DE-LA-ESTRELLA; CONVERGENT MARGIN; NICOYA PENINSULA; APRIL 22 AB [1] New seismic and geodetic data from Costa Rica provide insight into seismogenic zone processes in Central America, where the Cocos and Caribbean plates converge. Seismic data are from combined land and ocean bottom deployments in the Nicoya peninsula in northern Costa Rica and near the Osa peninsula in southern Costa Rica. In Nicoya, inversion of GPS data suggests two locked patches centered at 14 +/- 2 and 39 +/- 6 km depth. Interplate microseismicity is concentrated in the more freely slipping intermediate zone, suggesting that small interseismic earthquakes may not accurately outline the updip limit of the seismogenic zone, the rupture zone for future large earthquakes, at least over the short (similar to 1 year) observation period. We also estimate northwest motion of a coastal "sliver block'' at 8 +/- 3 mm/yr, probably related to oblique convergence. In the Osa region to the south, convergence is orthogonal to the trench. Cocos-Caribbean relative motion is partitioned here, with similar to 8 cm/yr on the Cocos-Panama block boundary ( including a component of permanent shortening across the Fila Costena fold and thrust belt) and similar to 1 cm/yr on the Panama block - Caribbean boundary. The GPS data suggest that the Cocos plate - Panama block boundary is completely locked from similar to 10 - 50 km depth. This large locked zone, as well as associated forearc and back-arc deformation, may be related to subduction of the shallow Cocos Ridge and/or younger lithosphere compared to Nicoya, with consequent higher coupling and compressive stress in the direction of plate convergence. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. Univ Calif Santa Cruz, Dept Earth Sci, Santa Cruz, CA 95064 USA. Univ Nacl, Observ Vulcanol & Sismol Costa Rica, Heredia, Costa Rica. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Leibniz Inst Meereswissensch, IFM GEOMAR, D-24148 Kiel, Germany. SSFB574 Christian Albrechts Univ, Kiel, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. US Geol Survey, Menlo Pk, CA 94025 USA. RP Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. EM enorabueana@rsmas.miami.edu; tdixon@rsmas.miami.edu; sschwartz@es.ucsc.edu; anewman@lanl.gov; jprotti@una.ac.cr; eflueh@ifm-geomar.de; paul@weed.jpl.nasa.gov; fpollitz@usgs.gov RI Newman, Andrew/E-7682-2012; Norabuena, Edmundo/I-5486-2013 OI Newman, Andrew/0000-0001-7414-1197; NR 109 TC 73 Z9 75 U1 3 U2 7 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 NOV 9 PY 2004 VL 109 IS B11 AR B11403 DI 10.1029/2003JB002931 PG 25 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 872ET UT WOS:000225191200003 ER PT J AU Rupnowski, P Gentz, M Sutter, JK Kumosa, M AF Rupnowski, P Gentz, M Sutter, JK Kumosa, M TI Mechanical response of a woven graphite/polyimide composite to in-plane shear dominated loads at room and elevated temperatures SO ACTA MATERIALIA LA English DT Article DE woven graphite/polyimide composites; shear response; modeling; finite element method; failure prediction; elevated temperature ID RAY-DIFFRACTION MEASUREMENTS; GRAPHITE FIBER/POLYIMIDE COMPOSITES; RESIDUAL THERMAL-STRESSES; +/-45-DEGREES TENSILE; ALUMINUM INCLUSIONS; BENDING LOADS; IOSIPESCU; TESTS; DAMAGE AB In this work, the effect of two types of in-plane shear dominated loads on the initiation of intralaminar damage has been evaluated in an 8-harness satin (8HS) T650-35/PMR-15 (graphite/polyimide) composite tested at room and elevated temperatures. The composite was subjected to either pure in-plane shear or combined biaxial tension and shear, which represented the stress conditions in the gage sections of the Iosipescu shear and +/-45degrees tensile tests, respectively. The stress distributions in the composite were determined as a function of load and temperature by performing non-linear stress computations on the micro-, meso- and macro-levels. Both the concept of representative micro- and meso-unit-cells and the viscoelastic Eshelby/Mori-Tanaka approach were used in the analyses. The macro-response of the composite to the in-plane shear and biaxial loads was predicted at both temperatures and then validated by comparing it with the available experimental data. The micro-stress calculations have shown that on the micro-scale noticeably higher maximum principal stresses in the polyimide matrix in the vicinity of the graphite fibers were determined for the biaxial load case than in pure shear, both at room and high temperatures. It was shown that by using the numerical stress predictions, the experimentally observed differences can be explained in the initiation of tow micro-cracking in the woven composite subjected to the Iosipescu and +/-45degrees tests at room and elevated temperatures. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 Univ Denver, Dept Engn, Ctr Adv Mat & Struct, Denver, CO 80208 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Kumosa, M (reprint author), Univ Denver, Dept Engn, Ctr Adv Mat & Struct, 2390 S York St, Denver, CO 80208 USA. EM mkumosa@du.edu RI Rupnowski, Przemyslaw/B-3520-2008; OI Rupnowski, Przemyslaw/0000-0003-0040-418X NR 34 TC 13 Z9 14 U1 2 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD NOV 8 PY 2004 VL 52 IS 19 BP 5603 EP 5613 DI 10.1016/j.actamat.2004.08.019 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 867KC UT WOS:000224840500016 ER PT J AU Jaroenapibal, P Luzzi, DE Evoy, S Arepalli, S AF Jaroenapibal, P Luzzi, DE Evoy, S Arepalli, S TI Transmission-electron-microscopic studies of mechanical properties of single-walled carbon nanotube bundles SO APPLIED PHYSICS LETTERS LA English DT Article ID ELASTIC PROPERTIES; ROPES AB The mechanical properties of single-walled carbon nanotube bundles were studied via the observation of mechanical resonance in a transmission electron microscope. The bundles were capacitively actuated using tunable ac signals applied through a custom built specimen holder. Resonant frequencies ranging from 0.2 to 9 MHz were observed in bundles of diameters and lengths ranging from 15 to 70 nm, and from 1 to 10 mum, respectively. An effective bending modulus of E-b=76+/-4 GPa was extracted from the data. Onset of nonlinear frequency response was observed under large actuation amplitudes. (C) 2004 American Institute of Physics. C1 Univ Penn, Dept Mat Sci & Engn, Philadelphia, PA 19104 USA. NASA, GBTech Inc, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Jaroenapibal, P (reprint author), Univ Penn, Dept Mat Sci & Engn, 3231 Walnut St, Philadelphia, PA 19104 USA. EM evoy@ee.upenn.edu RI Arepalli, Sivaram/A-5372-2010 NR 21 TC 26 Z9 26 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 NOV 8 PY 2004 VL 85 IS 19 BP 4328 EP 4330 DI 10.1063/1.1815057 PG 3 WC Physics, Applied SC Physics GA 869DE UT WOS:000224962800021 ER PT J AU Pines, V Zlatkowski, M Chait, A AF Pines, V Zlatkowski, M Chait, A TI Phase transition dynamics of liquid phase precipitation from a supersaturated gas mixture SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LASER SCATTERING MEASUREMENTS; HOMOGENEOUS NUCLEATION RATES; FRAGMENT SIZE DISTRIBUTIONS; WATER DROPS; CONDENSATION COEFFICIENT; TERMINAL VELOCITY; BINARY-MIXTURES; GERM-FORMATION; GROWTH-RATE; SHOCK-TUBE AB This work presents a self-consistent description of phase transition dynamics of disperse liquid phase precipitating from a supersaturated gas mixture. The unified approach integrates the macroscale transport phenomena of cloud dynamics with the essential microphysical kinetic processes of droplet condensation, evaporation, and droplet collisions simultaneously taking place in stochastic population of liquid droplets. A complete set of governing equations with well-defined dissipative fluxes and kinetic rates is derived for phase transition dynamics from nucleation to postnucleation to coarsening stages. The local thermodynamics of precipitating system, which is considered as ternary mixture of disperse liquid phase and water vapor with dry air, is redefined to explicitly include on equal basis both the vapor content and liquid content into the fundamental thermodynamic relations and equation of state. The molecular kinetic flux regularization method for growth of submicron droplets is reexamined to include, among others, significant contribution of vapor molecular energy flux into total heat flux, resulting in new expressions for the droplet temperature, growth rate, and effective diffusion coefficients. The local kinetic rates are determined on the basis of microscale kinetic equation for the droplet distribution function. This is in contrast to commonly used semiempirical parametrization schemes for kinetic rates with adjustable parameters, wherein the probabilistic aspects of microphysical processes are not rigorously addressed. Stochastic diffusion interactions among droplets competing for the available water vapor and modifications in the kinetic equation for droplets growing in stochastic population with direct long-range diffusion interactions amongst them are discussed and formulated as well. (C) 2004 American Institute of Physics. C1 Case Western Reserve Univ, Dept Phys, Cleveland, OH 44135 USA. RP Chait, A (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM Arnon.Chait@grc.nasa.gov NR 73 TC 1 Z9 1 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 8 PY 2004 VL 121 IS 18 BP 8929 EP 8955 DI 10.1063/1.1803536 PG 27 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 866UM UT WOS:000224798900031 PM 15527359 ER PT J AU Hagan, DE Webster, CR Farmer, CB May, RD Herman, RL Weinstock, EM Christensen, LE Lait, LR Newman, PA AF Hagan, DE Webster, CR Farmer, CB May, RD Herman, RL Weinstock, EM Christensen, LE Lait, LR Newman, PA TI Validating AIRS upper atmosphere water vapor retrievals using aircraft and balloon in situ measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID AIRS/AMSU/HSB; SPECTROMETER; HYGROMETER; CLOUDS; ER-2 AB [ 1] This paper provides an initial assessment of the accuracy of the Atmospheric Infrared Sounder ( AIRS) water vapor retrievals from 500 to 100 mbar. AIRS satellite measurements are compared with accurate aircraft ( NASA WB57) and balloon in situ water vapor measurements obtained during the NASA Pre-Aura Validation Experiment ( Pre-AVE) in Costa Rica during Jan. 2004. AIRS retrieval ( each pressure level of a single footprint) of water vapor amount agrees with the in situ measurements to -25% or better if matched closely in time ( 1 hr) and space ( 50 100 km). Both AIRS and in situ measurements observe similar significant variation in moisture amount over a two-day period, associated with large-scale changes in weather patterns. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Harvard Univ, Dept Chem & Biol Chem, Boston, MA 02115 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Hagan, DE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM denise.e.hagan@jpl.nasa.gov RI Newman, Paul/D-6208-2012; Herman, Robert/H-9389-2012 OI Newman, Paul/0000-0003-1139-2508; Herman, Robert/0000-0001-7063-6424 NR 16 TC 20 Z9 20 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 NOV 6 PY 2004 VL 31 IS 21 AR L21103 DI 10.1029/2004GL020302 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 870CF UT WOS:000225030900001 ER PT J AU Garrett, TJ Heymsfield, AJ McGill, MJ Ridley, BA Baumgardner, DG Bui, TP Webster, CR AF Garrett, TJ Heymsfield, AJ McGill, MJ Ridley, BA Baumgardner, DG Bui, TP Webster, CR TI Convective generation of cirrus near the tropopause SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE tropopause cirrus; anvil cirrus; convection ID ENVIRONMENT INTERFACE INSTABILITY; TROPICAL TROPOPAUSE; THIN CIRRUS; SUBVISIBLE CIRRUS; SATELLITE-OBSERVATIONS; SPATIAL DIMENSIONS; OPTICAL-PROPERTIES; RADIATIVE IMPACTS; NASA ER-2; CLOUDS AB [1] During the July 2002 CRYSTAL-FACE field program based from Key West, Florida, aircraft measurements showed that long-lived thin tropopause cirrus (TTC) layers were often present above thunderstorm anvils. This paper describes these clouds and explores their possible origins. Measurements showed that the horizontal dimensions of TTC layers were nearly identical to convectively formed anvils beneath, but that TTC did not appear to have originated from convective detrainment. Rather, they appeared to have formed in stably stratified air derived from high altitudes near the tropopause. TTC were separated vertically from the top of the anvil by similar to1 km, they lacked precipitation particles, and they were strongly depleted in HDO, all of which indicate in situ formation. However, compared to surrounding clear air near the tropopause, TTC were enriched in moisture and trace gases. The degree of enrichment was consistent with mixing of air near the tropopause with the same convective air mass that produced the anvil. Unlike surrounding air, TTC had embedded a monochromatic gravity wave with a wavelength of 2 km and an amplitude of several hundred meters. This evidence, supported by a photograph from CRYSTAL-FACE, leads to the conjecture that TTC originate as stratiform pileus clouds that form near the tropopause ahead of vigorous convective uplift. We hypothesize that the pileus are penetrated by the convection, moistened through turbulent mixing, and once the convection subsides, they are sustained by radiative cooling due to the presence of the anvil layer beneath. C1 Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Nacl Autonoma Mexico, Ctr Ciencias Atmosfera, Mexico City, DF, Mexico. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. CALTECH, Jet Prop Lab, Div Earth & Space Sci, Pasadena, CA 91109 USA. RP Garrett, TJ (reprint author), Univ Utah, Dept Meteorol, 135 S 1460 E,Room 819, Salt Lake City, UT 84112 USA. EM tgarrett@met.utah.edu RI Heymsfield, Andrew/E-7340-2011; McGill, Matthew/D-8176-2012 NR 49 TC 33 Z9 33 U1 1 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 NOV 6 PY 2004 VL 109 IS D21 AR D21203 DI 10.1029/2004JD004952 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 870CK UT WOS:000225031400010 ER PT J AU Choi, YH Wang, Y AF Choi, YH Wang, Y TI Dynamics of carbon sequestration in a coastal wetland using radiocarbon measurements SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article DE C accumulation; coastal wetland; radiocarbon ID SOIL ORGANIC-MATTER; ATMOSPHERIC CARBON; SALT-MARSH; PEAT; STORAGE; CO2; PEATLANDS; RESPONSES; METHANE; ACCUMULATION AB [ 1] Coastal wetlands are sensitive to global climate change and may play an important role in the global carbon cycle. However, the dynamics of carbon ( C) cycling in coastal wetlands and its response to sea level change associated with global warming is still poorly understood. In this study, we estimated the long-term and short-term rates of C accumulation, using C and C isotopic measurements of peat cores collected along a soil chronosequence, in a coastal wetland in north Florida. The long-term C accumulation rates determined by examining the C inventory and the radioactive decay of radiocarbon as a function of depth in the peat cores decrease with time from -130 +/- 9 g C/m(2)/yr over the last century to -13 +/- 2 g C/m(2)/yr over the millennium timescale. The short-term C accumulation rates estimated by examining the differences in the radiocarbon and C contents of the surfacial peat between archived ( 1985, 1988) and present ( 1996 and 1997) samples range from 42 to 193 g C/m(2)/yr in low marsh, from 18 to 184 g C/m(2)/yr in middle marsh, and from -50 to 181 g C/m(2)/yr in high marsh. The high end-values of our estimated short-term C accumulation rates are comparable to the estimated rates of C sequestration in coastal wetlands reported by Chmura et al. [ 2003], but are significantly higher than our estimated long-term rates in the marshes and are also much higher than the published rates of C sequestration in northern peatlands. The higher recent rates of C accumulation in coastal marshes, in comparison with the longer-term rates, are due to slow but continuous decomposition of organic matter in the peat over time. However, other factors such as increased primary production in the coastal wetland over the last decades or century, due to a rise in mean sea level and/or CO2 and nitrogen fertilization effect, could also have contributed to the large difference between the recent and longer-term rates. Our data indicate that salt marshes in this area have been and continue to be a sink for atmospheric carbon dioxide. Because of higher rates of C sequestration and lower CH4 emissions, coastal wetlands could be more valuable C sinks per unit area than other ecosystems in a warmer world. C1 Florida State Univ, Dept Geol Sci, Tallahassee, FL 32306 USA. RP Choi, YH (reprint author), NASA, Langley Res Ctr, Chem & Dynam Branch, MS483, Hampton, VA 23681 USA. EM y.choi@larc.nasa.gov NR 67 TC 6 Z9 6 U1 5 U2 36 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD NOV 5 PY 2004 VL 18 IS 4 AR GB4016 DI 10.1029/2004GB002261 PG 12 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 870CG UT WOS:000225031000004 ER PT J AU Kloepfer, JA Cohen, N Nadeau, JL AF Kloepfer, JA Cohen, N Nadeau, JL TI FRET between CdSe quantum dots in lipid vesicles and water- and lipid-soluble dyes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CHARGE-SHIFT PROBES; ENERGY-TRANSFER; EXCITED-STATE; MEMBRANE; NANOCRYSTALS; FLUORESCENCE; SPECTRA; BINDING; DONORS; FUSION AB Because of the coatings needed to solubilize and passivate quantum dots for biological applications, their use in fluorescent resonance energy transfer (FRET) has been limited. However, hydrophobic particles without polymer coatings may be embedded into lipid membranes, as demonstrated here with biomimetic vesicles. FRET is seen to a lipid-soluble dye (DiD) and a water-soluble dye (Cy3.5) in which the vesicles are suspended. The degree of energy transfer to each dye suggests that most of the QDs are located deep within the lipid, as confirmed by electron microscopy of whole mounts and thin sections of vesicles. Energy transfer is also seen to a voltage-sensitive, lipid-soluble dye (di-4-ANEPPS) only when the potassium ionophore valinomycin is present in the membrane. The effect is dependent upon potassium ion concentration rather than absolute membrane potential. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Leeds, Sch Comp, Leeds LS2 9JT, W Yorkshire, England. RP Nadeau, JL (reprint author), McGill Univ, Dept Biomed Engn, 3775 Univ St, Montreal, PQ H3A 2B4, Canada. EM jay.nadeau@mcgill.ca NR 28 TC 53 Z9 53 U1 1 U2 35 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 NOV 4 PY 2004 VL 108 IS 44 BP 17042 EP 17049 DI 10.1021/jp048094c PG 8 WC Chemistry, Physical SC Chemistry GA 867CT UT WOS:000224820500009 ER PT J AU Yeomans, DK Veverka, J AF Yeomans, DK Veverka, J TI Fred Lawrence Whipple (1906-2004) - Obituary SO NATURE LA English DT Biographical-Item C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Cornell Univ, Ctr Radio Phys & Space Res, Ithaca, NY 14850 USA. Cornell Univ, Planetary Studies Lab, Ithaca, NY 14850 USA. RP Yeomans, DK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM donald.k.yeomans@jpl.nasa.gov; jfv4@cornell.edu NR 0 TC 1 Z9 1 U1 0 U2 0 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD NOV 4 PY 2004 VL 432 IS 7013 BP 31 EP 31 DI 10.1038/432031a PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 867PQ UT WOS:000224854900028 PM 15525970 ER PT J AU Prange, R Pallier, L Hansen, KC Howard, R Vourlidas, A Courtin, G Parkinson, C AF Prange, R Pallier, L Hansen, KC Howard, R Vourlidas, A Courtin, G Parkinson, C TI An interplanetary shock traced by planetary auroral storms from the Sun to Saturn SO NATURE LA English DT Article ID EXTREME ULTRAVIOLET OBSERVATIONS; SOLAR-WIND; KILOMETRIC RADIATION; VOYAGER-1 ENCOUNTER; RADIO-EMISSION; CONVECTION; DYNAMICS; JUPITER; CAMERA; FIELD AB A relationship between solar activity and aurorae on Earth was postulated(1,2) long before space probes directly detected plasma propagating outwards from the Sun(3). Violent solar eruption events trigger interplanetary shocks(4) that compress Earth's magnetosphere, leading to increased energetic particle precipitation into the ionosphere and subsequent auroral storms(5,6). Monitoring shocks is now part of the 'Space Weather' forecast programme aimed at predicting solar-activity-related environmental hazards. The outer planets also experience aurorae, and here we report the discovery of a strong transient polar emission on Saturn, tentatively attributed to the passage of an interplanetary shock - and ultimately to a series of solar coronal mass ejection (CME) events. We could trace the shock-triggered events from Earth, where auroral storms were recorded, to Jupiter, where the auroral activity was strongly enhanced, and to Saturn, where it activated the unusual polar source. This establishes that shocks retain their properties and their ability to trigger planetary auroral activity thoughout the Solar System. Our results also reveal differences in the planetary auroral responses on the passing shock, especially in their latitudinal and local time dependences. C1 Observ Paris, LESIA, F-92195 Meudon, France. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. USN, Res Lab, Washington, DC 20375 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. NASA, Astrobiol Inst, Pasadena, CA 91125 USA. RP Prange, R (reprint author), Observ Paris, LESIA, 5 Pl Jules Janssen, F-92195 Meudon, France. EM renee.prange@obspm.fr RI Vourlidas, Angelos/C-8231-2009; Hansen, Kenneth/F-3693-2011 OI Vourlidas, Angelos/0000-0002-8164-5948; Hansen, Kenneth/0000-0002-8502-1980 NR 29 TC 76 Z9 76 U1 0 U2 4 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD NOV 4 PY 2004 VL 432 IS 7013 BP 78 EP 81 DI 10.1038/nature02986 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 867PQ UT WOS:000224854900041 PM 15525983 ER PT J AU Jackman, CM Achilleos, N Bunce, EJ Cowley, SWH Dougherty, MK Jones, GH Milan, SE Smith, EJ AF Jackman, CM Achilleos, N Bunce, EJ Cowley, SWH Dougherty, MK Jones, GH Milan, SE Smith, EJ TI Interplanetary magnetic field at similar to 9 AU during the declining phase of the solar cycle and its implications for Saturn's magnetospheric dynamics SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE interplanetary magnetic field; Saturn's magnetospheric dynamics; solar wind-magnetosphere coupling; Cassini space mission; substorms; reconnection voltage ID IONOSPHERE COUPLING CURRENTS; QUASI-STEADY DYNAMICS; MAIN AURORAL OVAL; MIDDLE MAGNETOSPHERE; WIND; NORTHWARD; MORPHOLOGY; MODEL; FLOWS; IMF AB [1] We study the interplanetary magnetic field ( IMF) data obtained by the Cassini spacecraft during a similar to 6.5-month interval when the spacecraft was approaching Saturn at heliocentric distances between similar to 8.5 and similar to 8.9 AU. It is shown that the structure of the IMF is consistent with that expected to be formed by corotating interaction regions (CIRs) during the declining phase of the solar cycle, with two sectors during each solar rotation, and crossings of the heliospheric current sheet generally embedded within few-day higher-field compression regions, separated by several-day lower-field rarefaction regions. This pattern was disrupted in November 2003, however, by an interval of high activity on the Sun. These data have then been employed to estimate the voltage associated with open flux production at Saturn's magnetopause using an empirical formula adapted from Earth. The results show that the CIR-related structuring of the IMF leads to corresponding structuring of the interplanetary interaction with Saturn's magnetosphere and hence also to intervals of very different dynamical behavior. During few-day compression regions where the IMF strength is similar to 0.5 - 2 nT, the average Dungey cycle voltage is estimated to be similar to 100 kV, such that the open flux produced over such intervals is similar to 30 - 40 GWb, similar to the typical total amount present in Saturn's magnetosphere. The magnetosphere is thus significantly driven by the solar wind interaction during such intervals. During some rarefaction intervals, on the other hand, the field strength remains similar to 0.1 nT or less over several days, implying reconnection voltages of similar to 10 kV or less, with negligible production of open flux. The magnetosphere is then expected to enter a quiescent state, dominated by internal processes. Overall, similar to 100 GWb of open flux is estimated to be produced during each similar to 25-day solar rotation, about 3 times the typical flux contained in the tail, and sufficient to drive three to five substorms. We point out, however, that CIR-related variations in solar wind dynamic pressure will also occur in synchronism with the field variations, which may also play a role in modulating the open flux in the system, thus reinforcing the synchronization of the pattern of growth and decay of open flux to the CIR pattern. Estimates of open flux production associated with the period of strong solar activity indicate that major magnetospheric dynamics were excited by reconnection-mediated solar wind interaction during this interval. C1 Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jackman, CM (reprint author), Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. EM cj47@ion.le.ac.uk RI Achilleos, Nicholas/C-1647-2008; Jones, Geraint/C-1682-2008; Bunce, Emma/I-9067-2016; OI Bunce, Emma/0000-0002-9456-0345; Jackman, Caitriona/0000-0003-0635-7361 NR 61 TC 82 Z9 82 U1 0 U2 7 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 NOV 3 PY 2004 VL 109 IS A11 AR A11203 DI 10.1029/2004JA010614 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 870CX UT WOS:000225032700004 ER PT J AU Lemon, C Wolf, RA Hill, TW Sazykin, S Spiro, RW Toffoletto, FR Birn, J Hesse, M AF Lemon, C Wolf, RA Hill, TW Sazykin, S Spiro, RW Toffoletto, FR Birn, J Hesse, M TI Magnetic storm ring current injection modeled with the Rice Convection Model and a self-consistent magnetic field SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ELECTRIC-FIELD; SHEET; MAGNETOSPHERE AB [ 1] We simulate plasma transport from the plasma sheet to the ring current, for the first time including the feedback effect of the drifting particles on both the electric and magnetic fields. Results suggest that strong, steady adiabatic convection throughout the middle plasma sheet leads to a highly stretched inner plasma sheet, but no ring current particle flux increases. We subsequently impose a substantial reduction of the specific entropy PV(5/3) near midnight outside 10 RE, where P is particle pressure and V = xi ds/B is flux tube volume. This produces a strong enhancement of the asymmetric ring current, which becomes symmetric when the pressure depletion and strong convection are quelled. We suggest that a reduction of the specific entropy in a region of the inner plasma sheet, apparently by some process that violates the assumption of adiabatic drift, plays a major role in the injection of a storm-time ring current. C1 Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. Los Alamos Natl Lab, Los Alamos, NM USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lemon, C (reprint author), Rice Univ, Dept Phys & Astron, 6100 Main St, Houston, TX 77005 USA. EM colby@rice.edu RI Hesse, Michael/D-2031-2012; Sazykin, Stanislav/C-3775-2008 OI Sazykin, Stanislav/0000-0002-9401-4248 NR 20 TC 63 Z9 64 U1 1 U2 7 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 NOV 2 PY 2004 VL 31 IS 21 AR L21801 DI 10.1029/2004GL020914 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 870CA UT WOS:000225030400003 ER PT J AU Matsui, T Kreidenweis, SM Pielke, RA Schichtel, B Yu, HB Chin, M Chu, DA Niyogi, D AF Matsui, T Kreidenweis, SM Pielke, RA Schichtel, B Yu, HB Chin, M Chu, DA Niyogi, D TI Regional comparison and assimilation of GOCART and MODIS aerosol optical depth across the eastern US SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TROPOSPHERIC AEROSOL; MODEL AB [ 1] This study compares aerosol optical depths (AOD) products from the Moderate Resolution Imaging Spectroradiometer ( MODIS) and the Goddard Chemistry Aerosol Radiation and Transport (GOCART) model and their integrated products with ground measurements across the eastern U. S. from March 1, 2000 to December 31, 2001. The Terra MODIS Level-3 ( collection 4) AOD at 0.55 mum has better correlation, but consistently overestimates the values of the Aerosol Robotic Network (AERONET) measurements. GOCART has small biases for a 22-month integration, and slight positive biases appeared for the cold season. These results are also supported by the comparison with the IMPROVE ( Interagency Monitoring of Protected Visual Environments) light extinction index. The optimal interpolation improves the daily-scale RMSE from either MODIS or GOCART alone. However, the regional biases in the aerosol products constitute a major constraint to the optimal estimate of AOD. C1 Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. N Carolina State Univ, Dept Marine Earth & Atmospher Sci, Raleigh, NC 27695 USA. RP Matsui, T (reprint author), Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. EM matsuit@atmos.colostate.edu RI Yu, Hongbin/C-6485-2008; Pielke, Roger/A-5015-2009; Chin, Mian/J-8354-2012; Kreidenweis, Sonia/E-5993-2011 OI Yu, Hongbin/0000-0003-4706-1575; Kreidenweis, Sonia/0000-0002-2561-2914 NR 9 TC 20 Z9 20 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 NOV 2 PY 2004 VL 31 IS 21 AR L21101 DI 10.1029/2004GL021017 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 870CA UT WOS:000225030400005 ER PT J AU Shindell, DT Walter, BP Faluvegi, G AF Shindell, DT Walter, BP Faluvegi, G TI Impacts of climate change on methane emissions from wetlands SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERIC METHANE; NATURAL WETLANDS; MODEL; SIMULATION; CYCLE; AIR AB [ 1] We have included climate-sensitive methane emissions from wetlands within the GISS climate model using a linear parameterization derived from a detailed process model. The geographic distribution of wetlands is also climate dependent. Doubled CO2 simulations using this model show an increase in annual average wetland methane emissions from 156 to 277 Tg/yr, a rise of 78%. The bulk of this increase is due to enhanced emissions from existing tropical wetlands. Additionally, high northern latitude wetland areas expand and emissions nearly triple during Northern summer. The global increase represents -20% of present-day inventories. These large values indicate that the potential response of natural emissions to climate change merit greater study, and should be included in projections of future global warming and tropospheric pollution. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, New York, NY 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 22 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 NOV 2 PY 2004 VL 31 IS 21 AR L21202 DI 10.1029/2004GL021009 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 870CA UT WOS:000225030400004 ER PT J AU Holstein, GR Rabbitt, RD Martinelli, GP Friedrich, VL Boyle, RD Highstein, SM AF Holstein, GR Rabbitt, RD Martinelli, GP Friedrich, VL Boyle, RD Highstein, SM TI Convergence of excitatory and inhibitory hair cell transmitters shapes vestibular afferent responses SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID PERIPHERAL INNERVATION PATTERNS; SEMICIRCULAR CANAL AFFERENTS; OPSANUS-TAU; CRISTA-AMPULLARIS; SQUIRREL-MONKEY; DYNAMICS; STIMULATION; TOADFISH; CHINCHILLA; ORGANIZATION AB The vestibular semicircular canals respond to angular acceleration that is integrated to angular velocity by the biofluid mechanics of the canals and is the primary origin of afferent responses encoding velocity. Surprisingly, some afferents actually report angular acceleration. Our data indicate that hair-cell/afferent synapses introduce a mathematical derivative in these afferents that partially cancels the biomechanical integration and results in discharge rates encoding angular acceleration. We examined the role of convergent synaptic inputs from hair cells to this mathematical differentiation. A significant reduction in the order of the differentiation was observed for low-frequency stimuli after gamma-aminobutyric acid type B receptor antagonist administration. Results demonstrate that gamma-aminobutyric acid participates in shaping the temporal dynamics of afferent responses. C1 Mt Sinai Sch Med, Dept Neurol, New York, NY 10029 USA. Mt Sinai Sch Med, Dept Neurosci, New York, NY 10029 USA. Univ Utah, Dept Bioengn, Salt Lake City, UT 84112 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Washington Univ, Sch Med, Dept Otolaryngol, St Louis, MO 63110 USA. Marine Biol Lab, Woods Hole, MA 02543 USA. RP Holstein, GR (reprint author), Mt Sinai Sch Med, Dept Neurol, New York, NY 10029 USA. EM gay.holstein@mssm.edu FU NCI NIH HHS [R24 CA095823, R24 CA 095823]; NIDCD NIH HHS [R01 DC006685, R55 DC 05585, P01 DC001837, P01 DC 01837] NR 31 TC 31 Z9 31 U1 0 U2 1 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 NOV 2 PY 2004 VL 101 IS 44 BP 15766 EP 15771 DI 10.1073/pnas.0402824101 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 868OG UT WOS:000224922300040 PM 15505229 ER PT J AU Jules, K McPherson, K Hrovat, K Kelly, E AF Jules, K McPherson, K Hrovat, K Kelly, E TI Initial characterization of the microgravity environment of the international space station: increments 2 through 4 SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 53rd International Astronautical Congress CY OCT 10-19, 2002 CL Houston, TX AB The primary objective of the International Space Station (ISS) is to provide a long-term quiescent environment for the conduct of scientific research for a variety of microgravity science disciplines. This paper reports to the microgravity scientific community the results of an initial characterization of the microgravity environment on the International Space Station for increments 2 through 4. During that period almost 70, 000 hours of station operations and scientific experiments were conducted. 720 hours of crew research time were logged aboard the orbiting laboratory and over half a terabyte of acceleration data were recorded and much of that was analyzed. The results discussed in this paper cover both the quasi-steady and vibratory acceleration environment of the station during its first year of scientific operation. For the quasi-steady environment, results are presented and discussed for the following: the space station attitudes Torque Equilibrium Attitude and the X-Axis Perpendicular to the Orbital Plane; station docking attitude maneuvers; Space Shuttle joint operation with the station; cabin de-pressurizations and the station water dumps. For the vibratory environment, results are presented for the following: crew exercise, docking events, and the activation/de-activation of both station life support system hardware and experiment hardware. Finally, a grand summary of all the data collected aboard the station during the I-year period is presented showing where the overall quasi-steady and vibratory acceleration magnitude levels fall over that period of time using a 95th percentile benchmark. Published by Elsevier Ltd. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. ZIN Technol Inc, Cleveland, OH 44135 USA. RP Jules, K (reprint author), NASA, Glenn Res Ctr, Mail Stop 77-7,21000 Brookpk Rd, Cleveland, OH 44135 USA. EM kenol.jules@grc.nasa.gov NR 17 TC 6 Z9 6 U1 2 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD NOV PY 2004 VL 55 IS 10 BP 855 EP 887 DI 10.1016/j.avtaastro.2004.04.008 PG 33 WC Engineering, Aerospace SC Engineering GA 850LD UT WOS:000223611900003 PM 15806736 ER PT J AU Dhaniyala, S Wennberg, PO Flagan, RC Fahey, DW Northway, MJ Gao, RS Bui, TP AF Dhaniyala, S Wennberg, PO Flagan, RC Fahey, DW Northway, MJ Gao, RS Bui, TP TI Stratospheric aerosol sampling: Effect of a blunt-body housing on inlet sampling characteristics SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID LARGE HNO3-CONTAINING PARTICLES; ARCTIC STRATOSPHERE; REACTIVE NITROGEN; WINTER; CLOUD; SIMULATION; DEPLETION; GROWTH; WATER AB During a campaign to study ozone loss mechanisms in the Arctic stratosphere ( SOLVE), several instruments on NASA's ER-2 aircraft observed a very low number density ( 0.1 1(-1)) of large, nitric-acid-containing particles that form the polar stratospheric clouds ( PSCs). For effective physical and chemical characterization of these particles, the measurements from these instruments have to be intercompared and integrated. In particular, proper interpretation requires knowledge of the sampling characteristics of the particles into the instruments. Here, we present the calculation of the sampling characteristics of the one of the instruments on the ER-2, the NOAA NOy instrument. This instrument sampled ambient particles and gas from two forward-facing inlets located fore and aft on a particle-separation housing ( the football) and measured total NOy in the sample. In recent studies, ambient aerosol mass has been estimated by the difference of the measurements of the two inlets with the assumption that the rear inlet observations represent the gas-phase NOy and small particles and the front inlet samples represent gas-phase NOy and all particle sizes with varied efficiency ( anisokinetic sampling). This knowledge was derived largely from semiempirical relations and potential flow studies of the housing. In our study, we used CFD simulations to model the compressible flow conditions and considered noncontinuum effects in calculating particle trajectories. Our simulations show that the blunt body housing the inlets has a strong and complex interaction with the flow and particles sampled by the two inlets. The simulations show that the front inlet characteristics are influenced by the effect of the blunt body on the upstream pressure field. The rear inlet sampling characteristics are influenced both by the shape and size of the inlet and its location on the blunt body. These interactions result in calculated inlet characteristics that are significantly different from previously assumed values. Analysis of the SOLVE data, considering the ambient conditions and the calculated inlet sampling characteristics, in conjunction with thermodynamic growth modeling of super-cooled ternary solution ( STS) particles, provides validation of the CFD results. C1 Clarkson Univ, Dept Mech & Aeronaut Engn, Potsdam, NY 13699 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Div Engn & Appl Sci, Pasadena, CA 91125 USA. CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Clarkson Univ, Dept Mech & Aeronaut Engn, Box 5725, Potsdam, NY 13699 USA. EM sdhaniya@clarkson.edu RI Wennberg, Paul/A-5460-2012; Gao, Ru-Shan/H-7455-2013; Fahey, David/G-4499-2013 OI Fahey, David/0000-0003-1720-0634 NR 30 TC 5 Z9 5 U1 1 U2 4 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 0278-6826 EI 1521-7388 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD NOV PY 2004 VL 38 IS 11 BP 1080 EP 1090 DI 10.1080/027868290885818 PG 11 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 869NP UT WOS:000224991600005 ER PT J AU Amitay, M Parekh, DE AF Amitay, M Parekh, DE TI Active flow control on the stingray uninhabited air vehicle: Transient behavior SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA 33rd Fluid Dynamics Conference CY JUN 22-26, 2003 CL ORLANDO, FL SP Amer Inst Aeronaut & Astronaut ID NATURALLY SEPARATED FLOW; SYNTHETIC JETS; SOLID-SURFACE; REATTACHMENT; MANAGEMENT; EVOLUTION; DELAY; LAYER AB The application of leading-edge separation control on an uninhabited air vehicle (UAV) with 50-deg leading-edge sweep is investigated experimentally in a full-scale close-return wind tunnel using arrays of synthetic jet actuators. Active flow control is used to enhance vehicle control at moderate and high angles of attack for takeoff and landing activities or gust load alleviation. The surface-mounted synthetic jet actuators are operated in various waveforms where the carrier frequency is at least an order of magnitude higher than the characteristic shedding frequency of the UAV. Actuation yields a suction peak near the leading edge, however, while excitation with a sinusoidal waveform results in a sharp suction peak near the leading edge; pulse modulation yields a larger and wider suction peak. The flow transients associated with controlled reattachment and separation of the flow over the UAV are investigated using amplitude modulation of the actuation waveform by measuring the dynamic surface pressure at different locations on the upper surface of the UAV's wing. Phase-locked measurements show that the transients, associated with the onset of reattachment and separation, at high angles of attack are accompanied by the shedding of large-scale vortical structures and oscillations of the surface pressure. However, no oscillations are observed when the baseline flow is attached. C1 Rensselaer Polytech Inst, Dept Mech Aerosp & Nucl Engn, Troy, NY 12180 USA. NASA, Langley Res Ctr, Flow Phys & Control Branch, Hampton, VA 23681 USA. RP Amitay, M (reprint author), Rensselaer Polytech Inst, Dept Mech Aerosp & Nucl Engn, 110 8th St, Troy, NY 12180 USA. EM amitam@rpi.edu NR 25 TC 14 Z9 15 U1 0 U2 4 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 NOV PY 2004 VL 42 IS 11 BP 2205 EP 2215 DI 10.2514/1.5697 PG 11 WC Engineering, Aerospace SC Engineering GA 869FH UT WOS:000224968300004 ER PT J AU Goodsell, AM Kennelly, RA AF Goodsell, AM Kennelly, RA TI Accounting for Laminar run and trip drag in supersonic cruise performance testing SO AIAA JOURNAL LA English DT Article ID BOUNDARY-LAYER TRANSITION; FLOW; ROUGHNESS; SPEEDS AB Recent experimental assessment of cruise performance for a supersonic transport has led to reevaluation of some time-honored techniques for trip drag correction. Two wind-tunnel tests were conducted on a wing/body configuration at Mach 2.4 and Reynolds number 6.4 x 10(6). A method for determining corrections to the drag near the cruise angle of attack is presented. These corrections account for the trip drag associated with attempts to induce boundary-layer transition and for the effect of any laminar flow that persists on the model. Extensive flow visualization using a subliming chemical revealed that the boundary-layer trip was not consistently effective. Flow over a portion of the upper wing surface exhibited delayed transition for even the largest trip heights tested. Laminar run corrections based on measured transition locations were computed using flat-plate skin-friction formulas. Once corrected for laminar run, the drag was constant for small trip heights ("drag plateau") before linearly increasing with trip height. Therefore, a trip drag correction is required only for those trip heights beyond the plateau. It is concluded that correction for laminar run is essential and must precede evaluation of trip drag. Neither correction is negligible at the level of accuracy desired. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Object Insights Inc, Stanford, CA 94309 USA. RP Goodsell, AM (reprint author), NASA, Ames Res Ctr, Mail Stop 258-1, Moffett Field, CA 94035 USA. EM Aga.M.Goodsell@nasa.gov; RAKennelly@ObjectiveInsights.com NR 22 TC 1 Z9 1 U1 0 U2 2 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 NOV PY 2004 VL 42 IS 11 BP 2225 EP 2233 DI 10.2514/1.13138 PG 9 WC Engineering, Aerospace SC Engineering GA 869FH UT WOS:000224968300006 ER PT J AU Venkataraman, S Haftka, RT Sankar, BV Zhu, HD Blosser, ML AF Venkataraman, S Haftka, RT Sankar, BV Zhu, HD Blosser, ML TI Optimal functionally graded metallic foam thermal insulation SO AIAA JOURNAL LA English DT Article ID HEAT-TRANSFER; CONDUCTIVITY AB Optimum density profiles that minimize heat transmission through a metal foam thermal insulation under one-dimensional steady-state conditions are investigated. The effective thermal conductivity of the foam is derived in terms of cell parameters and the temperature. Maximizing the temperature at the outside wall of the insulation minimizes the heat conduction through the insulation because this maximizes the radiated heat. An optimality condition is derived, and the optimization problem is reduced to that of an ordinary, but a nonlinear differential equation, which is solved numerically. The optimum density variation through the thickness of the insulation for a given incident heat flux and the transmitted heat are presented for graded and uniform foams with open and closed cells. For open-cell foams, functional grading of the foam density can reduce the heat transfer through the foam for given thickness. Conversely, for a specified amount of heat transmission through the foam, the functionally graded foam insulation can be made thinner than uniform density foam insulation. C1 San Diego State Univ, Dept Aerosp Engn & Engn Mech, San Diego, CA 92182 USA. Univ Florida, Dept Aerosp Engn Mech & Engn Sci, Gainesville, FL 32611 USA. NASA, Langley Res Ctr, Aerosp Engn Met & Thermal Struct Branch, Hampton, VA 23681 USA. RP Venkataraman, S (reprint author), San Diego State Univ, Dept Aerosp Engn & Engn Mech, San Diego, CA 92182 USA. EM satchi@engineering.sdsu.edu; haftka@ufl.edu; sankar@ufl.edu; zhuhd@aero.ufl.edu; m.l.blosser@larc.nasa.gov OI Sankar, Bhavani/0000-0002-4556-1982 NR 12 TC 8 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 0001-1452 J9 AIAA J JI AIAA J. PD NOV PY 2004 VL 42 IS 11 BP 2355 EP 2363 DI 10.2514/1.7456 PG 9 WC Engineering, Aerospace SC Engineering GA 869FH UT WOS:000224968300020 ER PT J AU Pinzon, JE Wilson, JM Tucker, CJ Arthur, R Jahrling, PB Formenty, P AF Pinzon, JE Wilson, JM Tucker, CJ Arthur, R Jahrling, PB Formenty, P TI Trigger events: Enviroclimatic coupling of ebola hemorrhagic fever outbreaks SO AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE LA English DT Article ID SINGULAR-VALUE DECOMPOSITION; DIFFERENCE VEGETATION INDEX; COTE-DIVOIRE; RAIN-FOREST; VIRUS; GABON; CONGO; ECOLOGY; DECLINE; CLIMATE AB We use spatially continuous satellite data as a correlate of precipitation within tropical Africa and show that the majority of documented Ebola hemorrhagic fever outbreaks were closely associated with sharply drier conditions at the end of the rainy season. We propose that these trigger events may enhance transmission of Ebola virus from its cryptic reservoir to humans. These findings suggest specific directions to help understand the sylvatic cycle of the virus and may provide early warning tools to detect possible future outbreaks of this enigmatic disease. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Terr Phys Lab, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. WHO, Global Alert & Response Team, Dept Communicable Dis Surveillance & Response, Geneva, Switzerland. USA, Med Res Inst Infect Dis, Ft Detrick, MD 21702 USA. RP Pinzon, JE (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Terr Phys Lab, Code 923, Greenbelt, MD 20771 USA. EM pinzon@negev.gsfc.nasa.gov; wilson@isis.imac.georgetown.edu; compton@kratmos.gsfc.nasa.gov; rca8@cdc.gov; Peter.Jahring@det.amedd.army.mil; formenty@who.int NR 47 TC 44 Z9 47 U1 3 U2 32 PU AMER SOC TROP MED & HYGIENE PI MCLEAN PA 8000 WESTPARK DR, STE 130, MCLEAN, VA 22101 USA SN 0002-9637 EI 1476-1645 J9 AM J TROP MED HYG JI Am. J. Trop. Med. Hyg. PD NOV PY 2004 VL 71 IS 5 BP 664 EP 674 PG 11 WC Public, Environmental & Occupational Health; Tropical Medicine SC Public, Environmental & Occupational Health; Tropical Medicine GA 876CL UT WOS:000225473200026 PM 15569802 ER PT J AU Kim, HH Goins, GD Wheeler, RM Sager, JC AF Kim, HH Goins, GD Wheeler, RM Sager, JC TI Stomatal conductance of lettuce grown under or exposed to different light qualities SO ANNALS OF BOTANY LA English DT Article DE Lactuca sativa; lettuce; light-emitting diode (LED); light quality; stomatal conductance ID SOLANUM-TUBEROSUM-L; BLUE-LIGHT; EMITTING-DIODES; GUARD-CELLS; RED-LIGHT; GREEN LIGHT; VICIA-FABA; ZEAXANTHIN; CO2; SEEDLINGS AB Background and Aims The objective of this research was to examine the effects of differences in light spectrum on the stomatal conductance (G(s)) and dry matter production of lettuce plants grown Under a day/night cycle with different spectra, and also the effects on G(s) of short-term exposure to different spectra. Methods Lettuce (Lactuca sativa) plants were grown with 6 It dark and 18 h light under four different spectra, red-blue (RB), red-blue-green (RBG), green (GF) and white (CWF), and G(s) and plant growth were measured. Key Results and Conclusions Conductance of plants grown for 23 d under CWF rose rapidly on illumination to a maximum in the middle of the light period, then decreased again before the dark period when it was minimal. However, the maximum was smaller in plants grown under RB, RGB and GF. This demonstrates that spectral quality during growth affects the diurnal pattern of stomatal conductance. Although G(s) was smaller in plants grown under RGB than CWF, dry mass accumulation was greater, suggesting that G(s) did not limit carbon assimilation under these spectral conditions. Temporarily changing the spectral quality of the plants grown for 23 d under CWF, affected stomatal responses reversibly, confirming studies on epidermal strips. This study provides new information showing that G(s) is responsive to spectral quality during growth and, in the short-term, is not directly coupled to dry matter accumulation. (C) 2004 Annals of Botany Company. C1 NASA, Biomed Operat & Res Off, Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. N Carolina Agr & Tech State Univ, Dept Biol, Greensboro, NC 27411 USA. RP Kim, HH (reprint author), NASA, Biomed Operat & Res Off, Kennedy Space Ctr, Mail Code YA-E4-B, Kennedy Space Ctr, FL 32899 USA. EM hyeonhye.kim-1@ksc.nasa.gov NR 36 TC 60 Z9 74 U1 2 U2 33 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-7364 J9 ANN BOT-LONDON JI Ann. Bot. PD NOV PY 2004 VL 94 IS 5 BP 691 EP 697 DI 10.1093/aob/mch192 PG 7 WC Plant Sciences SC Plant Sciences GA 872PF UT WOS:000225219000005 PM 15347557 ER PT J AU Johnson, LF Herwitz, SR Lobitz, BM Dunagan, SE AF Johnson, LF Herwitz, SR Lobitz, BM Dunagan, SE TI Feasibility of monitoring coffee field ripeness with airborne multispectral imagery SO APPLIED ENGINEERING IN AGRICULTURE LA English DT Article DE remote sensing; UAV multi-spectral image processing; coffee; ripeness evaluation; harvest planning AB Multispectral images were collected by an unmanned aerial vehicle over a commercial coffee plantation during the 2002 harvest season. Selected scenes were georegistered to a base map and a mosaic of the study area was created Image segmentation was performed to identify and mask soil, shadow and cloud pixels. The remaining pixels. representing sunlit canopy, were assumed to be a mixture of four components: green leaf underripe fruit, ripe fruit, and overripe fruit. Field and laboratory instruments were used to measure the reflectance spectrum of each component. Based on these spectra, a ripeness index was developed for the airborne intagery that involved computing the per-pixel ratio of digital counts in spectral channels centered at 580 and 660 nm. Results were aggregated on a per-field basis. Mean ripeness index per field was significantly correlated with ground-based counts recorded by the grower. and to eventual harvest date. The results suggest that remote sensing methods may provide an alternative, more spatially comprehensive method for monitoring ripeness status and evaluating harvest readiness of this high-value agricultural commodity. C1 NASA, Ames Res Ctr, Div Earth Sci, Moffett Field, CA 94035 USA. Clark Univ, Grad Sch Geog, Worcester, MA 01610 USA. UAV Applicat Ctr, Moffett Field, CA USA. San Jose State Univ, San Jose, CA 95192 USA. RP NASA, Ames Res Ctr, Div Earth Sci, MS242-4, Moffett Field, CA 94035 USA. EM Ljohnson@mail.arc.nasa.gov NR 9 TC 11 Z9 11 U1 3 U2 12 PU AMER SOC AGRICULTURAL & BIOLOGICAL ENGINEERS PI ST JOSEPH PA 2950 NILES RD, ST JOSEPH, MI 49085-9659 USA SN 0883-8542 EI 1943-7838 J9 APPL ENG AGRIC JI Appl. Eng. Agric. PD NOV PY 2004 VL 20 IS 6 BP 845 EP 849 PG 5 WC Agricultural Engineering SC Agriculture GA 887NX UT WOS:000226313900015 ER PT J AU Barnes, RA Eplee, RE Patt, FS Kieffer, HH Stone, TC Meister, G Butler, JJ McClain, CR AF Barnes, RA Eplee, RE Patt, FS Kieffer, HH Stone, TC Meister, G Butler, JJ McClain, CR TI Comparison of SeaWiFS measurements of the Moon with the US Geological Survey lunar model SO APPLIED OPTICS LA English DT Article ID ON-ORBIT CALIBRATION; ZONE COLOR SCANNER; IRRADIANCE; TIME; NM AB The Sea-Viewing Wide-Field-of-View Sensor (SeaWiFS) has made monthly observations of the Moon since 1997. Using 66 monthly measurements, the SeaWiFS calibration team has developed a correction for the instrument's on-orbit response changes. Concurrently, a lunar irradiance model has been developed by the U.S. Geological Survey (USGS) from extensive Earth-based observations of the Moon. The lunar irradiances measured by SeaWiFS are compared with the USGS model. The comparison shows essentially identical response histories for SeaWiFS, with differences from the model of less than 0.05% per thousand days in the long-term trends. From the SeaWiFS experience we have learned that it is important to view the entire lunar image at a constant phase angle from measurement to measurement and to understand, as best as possible, the size of each lunar image. However, a constant phase angle is not required for using the USGS model. With a long-term satellite lunar data set it is possible to determine instrument changes at a quality level approximating that from the USGS lunar model. However, early in a mission, when the dependence on factors such as phase and libration cannot be adequately determined from satellite measurements alone, the USGS model is critical to an understanding of trends in instruments that use the Moon for calibration. This is the case for SeaWiFS. (C) 2004 Optical Society of America. C1 Sci Applicat Int Corp, Beltsville, MD 20705 USA. US Geol Survey, Flagstaff, AZ 86001 USA. Futuretech Corp, Greenbelt, MD USA. NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Barnes, RA (reprint author), Sci Applicat Int Corp, Beltsville, MD 20705 USA. EM rbarnes@seawifs.gsfc.nasa.gov RI Meister, Gerhard/F-7159-2012; Butler, James/D-4188-2013 NR 31 TC 39 Z9 39 U1 1 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 NOV 1 PY 2004 VL 43 IS 31 BP 5838 EP 5854 DI 10.1364/AO.43.005838 PG 17 WC Optics SC Optics GA 866NJ UT WOS:000224779900013 PM 15540442 ER PT J AU Lyon, PE Hoge, FE Wright, CW Swift, RN Yungel, JK AF Lyon, PE Hoge, FE Wright, CW Swift, RN Yungel, JK TI Chlorophyll biomass in the global oceans: satellite retrieval using inherent optical properties SO APPLIED OPTICS LA English DT Article ID MIDDLE ATLANTIC BIGHT; PHYTOPLANKTON; ABSORPTION; VARIABILITY; ALGORITHMS; INVERSION; SPECTRA; IMAGERY; MODEL AB In the upper layer of the global ocean, 2082 in situ chlorophyll biomass values are retrieved by concurrent satellite-derived inherent optical properties (IOP). It is found that (1) the phytoplankton absorption coefficient IOP alone does not provide satisfactory (Chl) retrieval; (2) the chromophoric dissolved organic matter (CDOM) absorption coefficient IOP must also be used to obtain satisfactory retrieval through proportional to alpha(ph) + palpha(CDOM) where p is a constant and alpha(ph) and alpha(CDOM), are, respectively, the phytoplankton and CDOM absorption coefficients; (3) the IOP-based retrieval performance is comparable to standard satellite reflectance ratio retrievals (that have CDOM absorption intrinsically embedded within them); (4) inclusion of the total backscattering coefficient IOP does not contribute significantly to retrieval; and (5) the new IOP-based algorithm may provide the possibility for future research to establish the actual role of extracellular CDOM from all sources in the intracellular production of chlorophyll biomass. C1 Wallops Flight Facil, Wallops Isl, VA 23337 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Lyon, PE (reprint author), Wallops Flight Facil, Wallops Isl, VA 23337 USA. EM frank.hoge@nasa.gov NR 16 TC 10 Z9 10 U1 0 U2 0 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 NOV 1 PY 2004 VL 43 IS 31 BP 5886 EP 5892 DI 10.1364/AO.43.005886 PG 7 WC Optics SC Optics GA 866NJ UT WOS:000224779900018 PM 15540447 ER PT J AU Horstjann, M Bakhirkin, YA Kosterev, AA Curl, RF Tittel, FK Wong, CM Hill, CJ Yang, RQ AF Horstjann, M Bakhirkin, YA Kosterev, AA Curl, RF Tittel, FK Wong, CM Hill, CJ Yang, RQ TI Formaldehyde sensor using interband cascade laser based quartz-enhanced photoacoustic spectroscopy SO APPLIED PHYSICS B-LASERS AND OPTICS LA English DT Article ID OPTICAL PARAMETRIC OSCILLATOR; CONTINUOUS-WAVE OPERATION; TUNABLE DIODE-LASER; HIGH-POWER; SPECTROMETER; AIR AB A novel continuous-wave mid-infrared distributed feedback interband cascade laser was utilized to detect and quantify formaldehyde (H2CO) using quartz-enhanced photoacoustic spectroscopy. The laser was operated at liquid-nitrogen temperatures and provided single-mode output powers of up to 12 mW at 3.53 mum (2832.5 cm(-1)). The noise equivalent (1sigma) detection sensitivity of the sensor was measured to be 2.2x10(-8) cm(-1) W (Hz)(-1/2) for H2CO in ambient air, which corresponds to a detection limit of 0.6 parts in 10(6) by volume (ppmv) for a 10 s sensor time constant and 3.4 mW laser power delivered to the sensor module. C1 Rice Univ, Rice Quantum Inst, Houston, TX 77251 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Tittel, FK (reprint author), Rice Univ, Rice Quantum Inst, Houston, TX 77251 USA. EM fkt@rice.edu NR 24 TC 63 Z9 65 U1 0 U2 9 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0946-2171 J9 APPL PHYS B-LASERS O JI Appl. Phys. B-Lasers Opt. PD NOV PY 2004 VL 79 IS 7 BP 799 EP 803 DI 10.1007/s00340-004-1659-3 PG 5 WC Optics; Physics, Applied SC Optics; Physics GA 868CV UT WOS:000224891200001 ER PT J AU Bjarnason, JE Chan, TLJ Lee, AWM Brown, ER Driscoll, DC Hanson, M Gossard, AC Muller, RE AF Bjarnason, JE Chan, TLJ Lee, AWM Brown, ER Driscoll, DC Hanson, M Gossard, AC Muller, RE TI ErAs : GaAs photomixer with two-decade tunability and 12 mu W peak output power SO APPLIED PHYSICS LETTERS LA English DT Article AB This letter reports the fabrication and demonstration of an ErAs:GaAs interdigitated photomixer as a tunable THz source ranging from similar to20 GHz to similar to2 THz, with 12 muW maximum power typically around similar to90 GHz. Each photomixer is coupled to a composite dipole-spiral planar antenna that emits a Gaussian-type beam into free space. The beam switches from dipole to spiral antenna behavior as the frequency increases. A distributed Bragg reflector is embedded in the device beneath the photomixer to increase its external quantum efficiency. The photomixer has a 900 Angstrom thick silicon nitride coating which serves as an antireflection and passivation layer, and also improves the reliability and heat tolerance of the device. (C) 2004 American Institute of Physics. C1 Univ Calif Santa Barbara, ECE Dept, Santa Barbara, CA 93106 USA. Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. Jet Prop Lab, Pasadena, CA 91012 USA. RP Bjarnason, JE (reprint author), Univ Calif Santa Barbara, ECE Dept, Santa Barbara, CA 93106 USA. EM jeb@askur.org NR 7 TC 92 Z9 92 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 NOV 1 PY 2004 VL 85 IS 18 BP 3983 EP 3985 DI 10.1063/1.1813635 PG 3 WC Physics, Applied SC Physics GA 868DS UT WOS:000224894900009 ER PT J AU Brewer, JC Walters, RJ Bell, LD Farmer, DB Gordon, RG Atwater, HA AF Brewer, JC Walters, RJ Bell, LD Farmer, DB Gordon, RG Atwater, HA TI Determination of energy barrier profiles for high-k dielectric materials utilizing bias-dependent internal photoemission SO APPLIED PHYSICS LETTERS LA English DT Article ID ATOMIC LAYER DEPOSITION; KAPPA-GATE DIELECTRICS; AL2O3; SEMICONDUCTORS; INTERFACE; (100)SI; SILICON; STACKS; OXIDES; ISSUES AB We utilize bias-dependent internal photoemission spectroscopy to determine the metal/dielectric/silicon energy barrier profiles for Au/HfO2/Si and Au/Al2O3/Si structures. The results indicate that the applied voltage plays a large role in determining the effective barrier height and we attribute much of the variation in this case to image potential barrier lowering in measurements of single layers. By measuring current at both positive and negative voltages, we are able to measure the band offsets from Si and also to determine the flatband voltage and the barrier asymmetry at 0 V. Our SiO2 calibration sample yielded a conduction band offset value of 3.03+/-0.1 eV. Measurements on HfO2 give a conduction band offset value of 2.7+/-0.2 eV (at 1.0 V) and Al2O3 gives an offset of 3.3+/-0.1 (at 1.0 V). We believe that interfacial SiO2 layers may dominate the electron transport from silicon for these films. The Au/HfO2 barrier height was found to be 3.6+/-0.1 eV while the Au/Al2O3 barrier is 3.5+/-0.1 eV. (C) 2004 American Institute of Physics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Thomas J Watson Lab Appl Phys, Pasadena, CA 91125 USA. Harvard Univ, Dept Chem & Biol Chem, Cambridge, MA 02318 USA. RP Bell, LD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM lbell@pop.jpl.nasa.gov NR 20 TC 16 Z9 16 U1 0 U2 5 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 NOV 1 PY 2004 VL 85 IS 18 BP 4133 EP 4135 DI 10.1063/1.1812831 PG 3 WC Physics, Applied SC Physics GA 868DS UT WOS:000224894900059 ER PT J AU Lazarenkova, OL von Allmen, P Oyafuso, F Lee, S Klimeck, G AF Lazarenkova, OL von Allmen, P Oyafuso, F Lee, S Klimeck, G TI Effect of anharmonicity of the strain energy on band offsets in semiconductor nanostructures SO APPLIED PHYSICS LETTERS LA English DT Article ID QUANTUM DOTS; SPECTROSCOPY; DIAMOND AB Anharmonicity of the interatomic potential is taken into account for the quantitative simulation of the conduction and valence band offsets for strained semiconductor heterostructures. The anharmonicity leads to a weaker compressive hydrostatic strain than that obtained with the commonly used quasiharmonic approximation of the Keating model. Compared to experiment, inclusion of the anharmonicity in the simulation of strained InAs/GaAs nanostructures results in an improvement of the electron band offset computed on an atomistic level by up to 100 meV. (C) 2004 American Institute of Physics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Purdue Univ, Sch Elect & Comp Engn, Network Computat Nanotechnol, W Lafayette, IN 47906 USA. RP Lazarenkova, OL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM olga.l.lazarenkova@jpl.nasa.gov RI Klimeck, Gerhard/A-1414-2012 OI Klimeck, Gerhard/0000-0001-7128-773X NR 11 TC 34 Z9 34 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 NOV 1 PY 2004 VL 85 IS 18 BP 4193 EP 4195 DI 10.1063/1.1814810 PG 3 WC Physics, Applied SC Physics GA 868DS UT WOS:000224894900079 ER PT J AU Holland, ST Bersier, D Bloom, JS Garnavich, PM Caldwell, N Challis, P Kirshner, R Luhman, K McLeod, B Stanek, KZ AF Holland, ST Bersier, D Bloom, JS Garnavich, PM Caldwell, N Challis, P Kirshner, R Luhman, K McLeod, B Stanek, KZ TI GRB 021211 as a faint analog of GRB 990123: Exploring the similarities and differences in the optical afterglows SO ASTRONOMICAL JOURNAL LA English DT Article DE gamma rays : bursts ID GAMMA-RAY BURST; 28 FEBRUARY 1997; SUPERNOVA 2003DH; ENERGY-RELEASE; STAR-FORMATION; LIGHT CURVES; GRB 990123; EMISSION; VARIABILITY; PHOTOMETRY AB We present BVR(C)JHK(s) photometry of the optical afterglow of the gamma-ray burst GRB 021211 taken at the Magellan, MMT, and WIYN observatories between 0.7 and 50 days after the burst. We find an intrinsic spectral slope at optical and near-infrared wavelengths of 0.69 +/- 0.14 at 0.87 days. The optical decay during the first day is almost identical to that of GRB 990123 except that GRB 021211's optical afterglow was intrinsically approximately 38 times fainter and the transition from the reverse shock to the forward shock may have occurred earlier than it did for GRB 990123. We find no evidence for a jet break or the cooling break passing through optical frequencies during the first day after the burst. There is weak evidence for a break in the J-band decay between 0.89 and 1.87 days, which may be due to a jet. The optical and infrared data are consistent with a relativistic fireball where the shocked electrons are in the slow cooling regime and the electron index is 2.3 +/- 0.1. The forward shock appears to have been expanding in a homogeneous ambient medium during the first day after the burst. Our analysis suggests that the jet of GRB 021211 may have a small opening angle and that the total gamma-ray energy is likely to be much less than the canonical value of 1: 33; 1051 ergs. If this is the case, then it is possible that most of the energy of the burst is in another form such as a frozen magnetic field, supernova ejecta, or a second jet component. The host galaxy of GRB 021211 is subluminous and has a star formation rate of at least 1 M-. yr(-1). C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Harvard Soc Fellows, Cambridge, MA 02138 USA. RP NASA, Goddard Space Flight Ctr, Code 660-1, Greenbelt, MD 20771 USA. EM sholland@milkyway.gsfc.nasa.gov; bersier@stsci.edu; jbloom@cfa.harvard.edu; pgarnavi@miranda.phys.nd.edu; caldwell@cfa.harvard.edu; pchallis@cfa.harvard.edu; kirshner@cfa.harvard.edu; kluhman@cfa.harvard.edu; bcmcleod@cfa.harvard.edu; kstanek@cfa.harvard.edu NR 55 TC 24 Z9 24 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 NOV PY 2004 VL 128 IS 5 BP 1955 EP 1964 DI 10.1086/425048 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 867TX UT WOS:000224866500003 ER PT J AU Cross, NJG Bouwens, RJ Benitez, N Blakeslee, JP Menanteau, F Ford, HC Goto, T Holden, B Martel, AR Zirm, A Overzier, R Gronwall, C Homeier, N Clampin, M Hartig, GF Illingworth, GD Ardila, DR Bartko, F Broadhurst, TJ Brown, RA Burrows, CJ Cheng, ES Feldman, PD Franx, M Golimowski, DA Infante, L Kimble, RA Krist, JE Lesser, MP Meurer, GR Miley, GK Postman, M Rosati, P Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W AF Cross, NJG Bouwens, RJ Benitez, N Blakeslee, JP Menanteau, F Ford, HC Goto, T Holden, B Martel, AR Zirm, A Overzier, R Gronwall, C Homeier, N Clampin, M Hartig, GF Illingworth, GD Ardila, DR Bartko, F Broadhurst, TJ Brown, RA Burrows, CJ Cheng, ES Feldman, PD Franx, M Golimowski, DA Infante, L Kimble, RA Krist, JE Lesser, MP Meurer, GR Miley, GK Postman, M Rosati, P Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W TI The luminosity function of early-type field galaxies at z approximate to 0.75 SO ASTRONOMICAL JOURNAL LA English DT Article ID HUBBLE DEEP FIELD; GROTH STRIP SURVEY; FRANCE REDSHIFT SURVEY; ELLIPTIC GALAXIES; ADVANCED CAMERA; PHOTOMETRIC REDSHIFTS; SURFACE BRIGHTNESS; E/S0 GALAXIES; EVOLUTION; POPULATION AB We measure the luminosity function of morphologically selected E/S0 galaxies from z = 0.5 to 1.0 using deep high-resolution Advanced Camera for Surveys (ACS) imaging data. Our analysis covers an area of 48 arcmin(2) ( 8 times the area of the Hubble Deep Field North) and extends 2 mag deeper (I similar to 24 mag) than was possible in the Deep Groth Strip Survey (DGSS). Our fields were observed as part of the ACS Guaranteed Time Observations. At 0.5 < z < 0.75, we find M-B* - 5 log h(0.7) = - 21.1 +/- 0.3 and alpha = - 0.53 +/- 0.2, and at 0.75 < z < 1.0, we find M-B*-5 log h(0.7) = - 21.4 +/- 0.2, consistent with 0.3 mag of luminosity evolution ( across our two redshift intervals). These luminosity functions are similar in both shape and number density to the luminosity function using morphological selection ( e. g., DGSS), but are much steeper than the luminosity functions of samples selected using morphological proxies such as the color or spectral energy distribution (e.g., CFRS, CADIS, or COMBO-17). The difference is due to the "blue,'' (U - V)(0) < 1.7, E/S0 galaxies, which make up to &SIM; 30% of the sample at all magnitudes and an increasing proportion of faint galaxies. We thereby demonstrate the need for both morphological and structural information to constrain the evolution of galaxies. We find that the blue E/S0 galaxies have the same average sizes and Sersic parameters as the "red,'' (U - V)(0) > 1.7, E/S0 galaxies at brighter luminosities (M-B < -20.1), but are increasingly different at fainter magnitudes, where blue galaxies are both smaller and have lower Sersic parameters. We find differences in both the size-magnitude relation and the photometric plane offset for red and blue E/S0s, although neither red nor blue galaxies give a good fit to the size-magnitude relation. Fits of the colors to stellar population models suggest that most E/S0 galaxies have short star formation timescales (τ < 1 Gyr), and that galaxies have formed at an increasing rate from z similar to 8 until z similar to 2, after which there has been a gradual decline. 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. Leiden Observ, NL-2300 RA Leiden, Netherlands. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Bartko Sci & Technol, Mead, CO 80542 USA. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. 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. WM Keck Observ, Kamuela, HI 96743 USA. NASA Headquarters, Washington, DC 20546 USA. RP Cross, NJG (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 Menanteau, Felipe/0000-0002-1372-2534; Benitez, Narciso/0000-0002-0403-7455; Blakeslee, John/0000-0002-5213-3548 NR 58 TC 38 Z9 38 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 NOV PY 2004 VL 128 IS 5 BP 1990 EP 2012 DI 10.1086/424857 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 867TX UT WOS:000224866500006 ER PT J AU Chu, YH Gruendl, RA Williams, RM Gull, TR Werner, K AF Chu, YH Gruendl, RA Williams, RM Gull, TR Werner, K TI The nebular environment and enigmatic hard X-ray emission of the hot do white dwarf KPD 0005+5106 SO ASTRONOMICAL JOURNAL LA English DT Article DE HII regions; planetary nebulae : general; stars : individual (KPD 0005+5106); white dwarfs ID HUBBLE-SPACE-TELESCOPE; KPD 0005+5106; MASS; SPECTROSCOPY; DISCOVERY; SEARCH; STARS; FAINT AB We have detected an ionized nebula around the hot DO white dwarf KPD 0005+5106 and used the [O III]/Halpha ratios and nebular velocities to separate this nebula from the background H II region of AO Cas. The angular size of the [O III] nebula of KPD 0005+5106 is similar to3degrees. The velocity of this nebula is similar to those of the local interstellar H I gas and the interstellar/circumstellar absorption lines in the UV spectra of KPD 0005+5106 but has a large offset from those of the stellar photospheric lines. The mass of the ionized nebula, similar to70 M-circle dot, indicates that it consists of interstellar material and that the velocity offset between the star and the ambient medium should not be interpreted as a wind outflow. We have also analyzed the ROSAT PSPC observation of KPD 0005+5106 to determine its hard X-ray luminosity. Using the L-X=L-bol relation for late-type stars and the lack of obvious near-IR excess of KPD 0005+5106, we exclude the possible existence of a binary companion with coronal activity. Without a wind outflow, the presence of stellar O VIII emission requires that X-rays at energies greater than 0.871 keV are present in the vicinity of KPD 0005+5106. This hard X-ray emission is most puzzling, since neither photospheric emission at such high energies nor a high-temperature corona is expected from current stellar atmospheric models of KPD 0005+5106. X-ray observations with high angular resolution and sensitivity are needed to confirm the positional coincidence and to enable X-ray spectral analyses for constraining the physical origin of the hard X-ray emission from KPD 0005+5106. C1 Univ Illinois, Dept Astron, Urbana, IL 61801 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Tubingen, Inst Astron & Astrophys, D-72076 Tubingen, Germany. RP Chu, YH (reprint author), Univ Illinois, Dept Astron, 1002 W Green St, Urbana, IL 61801 USA. EM chu@astro.uiuc.edu; gruendl@astro.uiuc.edu; rosanina@astro.uiuc.edu; gull@sea.gsfc.nasa.gov; werner@astro.uni-tuebingen.de RI Gull, Theodore/D-2753-2012 OI Gull, Theodore/0000-0002-6851-5380 NR 22 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 0004-6256 J9 ASTRON J JI Astron. J. PD NOV PY 2004 VL 128 IS 5 BP 2357 EP 2363 DI 10.1086/424942 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 867TX UT WOS:000224866500028 ER PT J AU Porquet, D Reeves, JN Uttley, P Turner, TJ AF Porquet, D Reeves, JN Uttley, P Turner, TJ TI XMM-Newton observation of the Seyfert 1.8 ESO113-G010: Discovery of a highly redshifted iron line at 5.4 keV SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : active; galaxies : quasars : general; X-rays : general; line : formation; X-rays : individual : ESO 113-G010 ID ACTIVE GALACTIC NUCLEI; BLACK-HOLE SYSTEMS; CYGNUS X-1; ALPHA LINE; GALAXIES; SPECTROSCOPY; PROFILE; QUASARS; ROSAT; PROBE AB We present a spectral analysis of the Seyfert 1.8 ESO 113-G010 observed with XMM-Newton for 4 ks. The spectrum shows a soft excess below 0.7 keV and more interestingly a narrow emission Gaussian line at 5.4 keV ( in its rest-frame), most probably originating from a redshifted iron Kalpha line. No significant line at or above 6.4 keV is found contrary to other objects showing redshifted lines, ruling out a strong blue-wing to the line profile. The line is detected at 99% confidence, from performing Monte Carlo simulations which fully account for the range of energies where a narrow iron line is likely to occur. The energy of the line could indicate emission from relativistic (0.17 - 0.23 c) ejected matter moving away from the observer, as proposed for Mrk 766 by Turner et al. ( 2004, ApJ, 603, 62). Alternatively, the emission from a narrow annulus at the surface of the accretion disk is unlikely due to the very small inclination angle (i.e. less than 10degrees) required to explain the narrow, redshifted line in this intermediate Seyfert galaxy. However emission from a small, localized hot-spot on the disk, occurring within a fraction of a complete disk orbit, could also explain the redshifted line. This scenario would be directly testable in a longer observation, as one would see significant variations in the energy and intensity of the line within an orbital timescale. C1 Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Seabrook, MD 20706 USA. Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. RP Porquet, D (reprint author), Max Planck Inst Extraterr Phys, Postfach 1312, D-85741 Garching, Germany. EM dporquet@mpe.mpg.de OI Porquet, Delphine/0000-0001-9731-0352 NR 23 TC 49 Z9 49 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 NOV PY 2004 VL 427 IS 1 BP 101 EP 105 DI 10.1051/0004-6361:20041637 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869FP UT WOS:000224969100013 ER PT J AU Wiegert, T de Mello, DF Horellou, C AF Wiegert, T de Mello, DF Horellou, C TI Assessing the galaxy population out to z similar to 2 using the Hubble Deep Field South SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE cosmology : observations; galaxies : evolution; galaxies : statistics; galaxies : photometry ID HIGH-REDSHIFT GALAXIES; PHOTOMETRIC REDSHIFTS; EVOLUTION; CATALOG; REDUCTION; SEQUENCE; SPECTRA; COLORS; NORTH AB In this work we use the Hubble Deep Field South (HDF-S) version 2 images to assess the galaxy population out to z similar to 2. We have used two methods of templates fitting of the spectral energy distributions to obtain photometric redshifts and classify the objects. The Bayesian photometric redshifts gave better results when compared with 54 spectroscopic redshifts available in the literature. Analysis of the rest-frame colour distribution shows a bimodality out to z similar to 1.4. We separated our sample in a blue and a red population at B-V = 0.29. At low redshifts (0.2 < z < 0.6), similar to60% of the galaxies have B-V > 0.29 whereas at higher redshifts similar to60% of the galaxies are bluer than B-V < 0.29. Although in low numbers, a population of early-type galaxies (or heavily obscured low redshift galaxies) is seen out to z &SIM; 2. C1 Chalmers Univ Technol, Onsala Space Observ, S-43992 Onsala, Sweden. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Catholic Univ Amer, Washington, DC 20064 USA. RP Wiegert, T (reprint author), Univ Manitoba, Dept Phys & Astron, Winnipeg, MB R3T 2N2, Canada. EM wiegert@physics.umanitoba.ca NR 37 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 NOV PY 2004 VL 426 IS 2 BP 455 EP + DI 10.1051/0004-6361:20041015 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869EI UT WOS:000224965800015 ER PT J AU McMullin, DR Bzowski, M Mobius, E Pauluhn, A Skoug, R Thompson, WT Witte, M von Steiger, R Rucinski, D Judge, D Banaszkiewicz, M Lallement, R AF McMullin, DR Bzowski, M Mobius, E Pauluhn, A Skoug, R Thompson, WT Witte, M von Steiger, R Rucinski, D Judge, D Banaszkiewicz, M Lallement, R TI Heliospheric conditions that affect the interstellar gas inside the heliosphere SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ISM : general; ISM : atoms; interplanetary medium; plasmas ID PHOTOIONIZATION CROSS-SECTIONS; ELECTRON-IMPACT IONIZATION; PICK-UP IONS; SOLAR-WIND; HELIUM PARAMETERS; LATITUDINAL STRUCTURE; ULYSSES; HYDROGEN; CORE; HE AB The interstellar gas that flows through the heliosphere is strongly affected by ionization close to the Sun, in particular solar photoionization, electron impact, and charge exchange. Therefore, the interpretation of any observation of interstellar gas in the inner heliosphere hinges upon the accurate knowledge of these effects and their variations. In addition, the irradiance and line profile of the relevant solar spectral line are needed to properly interpret resonant backscattering observations of the interstellar neutral gas. With instrumentation on ACE, SOHO and Wind, continuous monitoring of these important environmental conditions simultaneously with a multitude of interstellar gas observations has become possible for the first time. In this paper we present a compilation of the processes and parameters that affect the distribution of interstellar helium inside the heliosphere and their observation, including the irradiance and line profile of the He 58.4 nm line. We also make the connection to proxies for these parameters and evaluate their accuracy in order to expand the time period of coverage wherever possible. C1 Univ So Calif, Ctr Space Sci, Los Angeles, CA 90089 USA. Praxis Inc, Alexandria, VA USA. PAS, Space Res Ctr, PL-00716 Warsaw, Poland. Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Int Space Sci Inst, CH-3012 Bern, Switzerland. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. CNRS, Serv Aeron, F-91371 Verrieres Le Buisson, France. RP McMullin, DR (reprint author), Univ So Calif, Ctr Space Sci, Los Angeles, CA 90089 USA. EM mcmullind@pxi.com RI Von Steiger, Rudolf/F-6822-2011; Thompson, William/D-7376-2012; OI Von Steiger, Rudolf/0000-0002-3350-0023; Moebius, Eberhard/0000-0002-2745-6978 NR 65 TC 29 Z9 30 U1 0 U2 4 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 NOV PY 2004 VL 426 IS 3 BP 885 EP 895 DI 10.1051/0004-6361:20047147 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869FL UT WOS:000224968700016 ER PT J AU Mobius, E Bzowski, M Chalov, S Fahr, HJ Gloeckler, G Izmodenov, V Kallenbach, R Lallement, R McMullin, D Noda, H Oka, M Pauluhn, A Raymond, J Rucinski, D Skoug, R Terasawa, T Thompson, W Vallerga, J von Steiger, R Witte, M AF Mobius, E Bzowski, M Chalov, S Fahr, HJ Gloeckler, G Izmodenov, V Kallenbach, R Lallement, R McMullin, D Noda, H Oka, M Pauluhn, A Raymond, J Rucinski, D Skoug, R Terasawa, T Thompson, W Vallerga, J von Steiger, R Witte, M TI Synopsis of the interstellar He parameters from combined neutral gas, pickup ion and UV scattering observations and related consequences SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE interplanetary medium; ISM : general; ISM : atoms; methods : observational; plasmas ID HELIUM FOCUSING CONE; ANOMALOUS COSMIC-RAYS; LYMAN-ALPHA; SOLAR-WIND; TERMINATION SHOCK; HELIOSPHERIC INTERFACE; ULYSSES/GAS-INSTRUMENT; IONIZATION PROCESSES; KINETIC-PARAMETERS; MAGNETIC-FIELD AB A coordinated effort to combine all three methods that are used to determine the physical parameters of interstellar gas in the heliosphere has been undertaken. In order to arrive at a consistent parameter set that agrees with the observations of neutral gas, pickup ions and UV backscattering we have combined data sets from coordinated observation campaigns over three years from 1998 through 2000. The key observations include pickup ions with ACE and Ulysses SWICS, neutral atoms with Ulysses GAS, as well as UV backscattering at the He focusing cone close to the Sun with SOHO UVCS and at 1 AU with EUVE. For the first time also the solar EUV irradiance that is responsible for photo ionization was monitored with SOHO CELIAS SEM, and the He I 58.4 nm line that illuminates He was observed simultaneously with SOHO SUMER. The solar wind conditions were monitored with SOHO, ACE, and WIND. Based on these data the modeling of the interstellar gas and its secondary products in the heliosphere has resulted in a consistent set of interstellar He parameters with much reduced uncertainties, which satisfy all observations, even extended to earlier data sets. It was also established that a substantial ionization in addition to photo ionization, most likely electron impact, is required, with increasing relative importance closer to the Sun. Furthermore, the total combined ionization rate varies significantly with solar latitude, requiring a fully three dimensional and time dependent treatment of the problem. C1 Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. Univ New Hampshire, Ctr Space Sci, Durham, NH 03824 USA. Polish Acad Sci, Space Res Ctr, PL-00716 Warsaw, Poland. Russian Acad Sci, Inst Problems Mech, Moscow 117526, Russia. Univ Bonn, Inst Astron & Extraterr Forsch, D-53121 Bonn, Germany. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Univ Maryland, Inst Phys Sci & Technol, College Pk, MD 20742 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. Moscow MV Lomonosov State Univ, Dept Mech & Math, Moscow 119899, Russia. ISSI, CH-3012 Bern, Switzerland. CNRS, Serv Aeron, F-91371 Verrieres Le Buisson, France. Univ So Calif, Ctr Space Sci, Los Angeles, CA 90089 USA. Natl Astron Observ Japan, Mizusawa, Iwate, Japan. Univ Tokyo, Dept Earth & Planetary Phys, Bunkyo Ku, Tokyo 113, Japan. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Max Planck Inst Solar Syst Res, D-37191 Katlenburg Lindau 3, Germany. RP Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. EM Eberhard.Moebius@unh.edu RI Von Steiger, Rudolf/F-6822-2011; Thompson, William/D-7376-2012; Izmodenov, Vladislav/K-6073-2012; OI Von Steiger, Rudolf/0000-0002-3350-0023; Izmodenov, Vladislav/0000-0002-1748-0982; Moebius, Eberhard/0000-0002-2745-6978 NR 84 TC 149 Z9 151 U1 0 U2 4 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 NOV PY 2004 VL 426 IS 3 BP 897 EP 907 DI 10.1051/0004-6361:20035834 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869FL UT WOS:000224968700017 ER PT J AU Moiseev, AA Ormes, JF Hartman, RC Johnson, TE Mitchell, JW Thompson, DJ AF Moiseev, AA Ormes, JF Hartman, RC Johnson, TE Mitchell, JW Thompson, DJ TI Observation and simulations of the backsplash effects in high-energy gamma-ray telescopes containing a massive calorimeter SO ASTROPARTICLE PHYSICS LA English DT Article DE backsplash; Gamma-ray telescope; anticoincidence detector; electromagnetic calorimeter ID EGRET AB Beam test and simulation results are presented for a study of the backsplash effects produced in a high-energy gamma-ray detector containing a massive calorimeter. An empirical formula is developed to estimate the probability (per unit area) of backsplash for different calorimeter materials and thickncsses, different incident particle energies, and at different distances from the calorimeter. The results obtained are applied to the design of the Anti-Coincidence Detector (ACD) for the Large Area Telescope (LAT) on the Gamma-ray Large Area Space Telescope (GLAST). (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Seabrook, MD 20706 USA. RP Moiseev, AA (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM moiseev@milkyway.gsfc.nasa.gov RI Thompson, David/D-2939-2012 OI Thompson, David/0000-0001-5217-9135 NR 9 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 J9 ASTROPART PHYS JI Astropart Phys. PD NOV PY 2004 VL 22 IS 3-4 BP 275 EP 283 DI 10.1016/j.astropartphys.2004.07.008 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 874JP UT WOS:000225347000004 ER PT J AU Reeves, JN Porquet, D Turner, TJ AF Reeves, JN Porquet, D Turner, TJ TI An extreme, blueshifted iron-line profile in the narrow-line Seyfert 1 PG 1402+261: An edge-on accretion disk or highly ionized absorption? SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; quasars : individual (PG 1402+261); X-rays : galaxies ID X-RAY REFLECTION; BLACK-HOLE MASSES; XMM-NEWTON; EMISSION; GALAXY; MCG-6-30-15; QUASARS; BROAD; SPECTRUM; OUTFLOW AB We report on a short XMM-Newton observation of the radio-quiet narrow-line Seyfert 1 galaxy PG 1402+261. The EPIC X-ray spectrum of PG 1402+261 shows a strong excess of counts between 6 and 9 keV in the rest frame. This feature can be modeled by an unusually strong ( equivalent width 2 keV) and very broad (FWHM velocity of 110,000 km s(-1)) iron K-shell emission line. The line centroid energy at 7.3 keV appears blueshifted with respect to the iron Kalpha emission band between 6.4 and 6.97 keV, while the blue wing of the line extends to 9 keV in the quasar rest frame. The line profile can be fitted by reflection from the inner accretion disk, but an inclination angle of >60degrees is required to model the extreme blue wing of the line. Furthermore, the extreme strength of the line requires a geometry whereby the hard X-ray emission from PG 1402+261 above 2 keV is dominated by the pure-reflection component from the disk, while little or none of the direct hard power law is observed. Alternatively, the spectrum above 2 keV may be explained by an ionized absorber, if the column density is sufficiently high (N-H > 3 x 10(23) cm(-2)) and if the matter is ionized enough to produce a deep (tau similar to 1) iron K-shell absorption edge at 9 keV. This absorber could originate in a large column density, high-velocity outflow, perhaps similar to those that appear to be observed in several other high accretion rate active galactic nuclei. Further observations, especially at higher spectral resolution, are required to distinguish between the accretion disk reflection and outflow scenarios. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Seabrook, MD 20706 USA. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Baltimore, MD 21250 USA. RP Reeves, JN (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 662, Greenbelt, MD 20771 USA. EM jnr@milkyway.gsfc.nasa.gov; dporquet@mpe.mpg.de; turner@milkyway.gsfc.nasa.gov OI Porquet, Delphine/0000-0001-9731-0352 NR 41 TC 10 Z9 10 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 NOV 1 PY 2004 VL 615 IS 1 BP 150 EP 155 DI 10.1086/424478 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 866GB UT WOS:000224760800013 ER PT J AU Papini, P Piccardi, S Spillantini, P Vannuccini, E Ambriola, M Bellotti, R Cafagna, F Ciacio, F Circella, M De Marzo, CN Bartalucci, S Ricci, M Bergstrom, D Carlson, P Francke, T Hansen, P Mocchiutti, E Boezio, M Bonvicini, V Schiavon, P Vacchi, A Zampa, N Bravar, U Stochaj, SJ Casolino, M De Pascale, MP Morselli, A Picozza, P Sparvoli, R Hof, M Kremer, J Menn, W Simon, M Mitchell, JW Ormes, JF Stephens, SA Streitmatter, RE Suffert, M AF Papini, P Piccardi, S Spillantini, P Vannuccini, E Ambriola, M Bellotti, R Cafagna, F Ciacio, F Circella, M De Marzo, CN Bartalucci, S Ricci, M Bergstrom, D Carlson, P Francke, T Hansen, P Mocchiutti, E Boezio, M Bonvicini, V Schiavon, P Vacchi, A Zampa, N Bravar, U Stochaj, SJ Casolino, M De Pascale, MP Morselli, A Picozza, P Sparvoli, R Hof, M Kremer, J Menn, W Simon, M Mitchell, JW Ormes, JF Stephens, SA Streitmatter, RE Suffert, M TI High-energy deuteron measurement with the CAPRICE98 experiment SO ASTROPHYSICAL JOURNAL LA English DT Article DE balloons; cosmic rays; Galaxy : abundances; ISM : abundances ID GALACTIC COSMIC-RAYS; MAGNETIC SPECTROMETER; CROSS-SECTIONS; ISOTOPIC COMPOSITION; ANTIPROTON FLUX; HELIUM SPECTRA; PERFORMANCE; CALORIMETER; PROPAGATION; ANTIMATTER AB We report the first measurement of the deuterium abundance in cosmic rays above 10 GeV nucleon(-1) of kinetic energy. The data were collected by the balloon-borne experiment CAPRICE98, which was flown on 1998 May 28-29 from Fort Sumner, New Mexico. The detector configuration included the NMSU-WiZard/CAPRICE superconducting magnet spectrometer equipped with a gas RICH detector, a silicon-tungsten calorimeter, and a time-of-flight system. By combining the information from the spectrometer and the RICH detector, it was possible to separate deuterons from protons in the kinetic energy range from 12 to 22 GeV nucleon(-1). In order to estimate the proton background and the deuteron selection efficiency, we developed an empirical model for the response of the instrument, based on the data collected in this experiment. The analysis procedure is described in this paper, and the result on the absolute flux of deuterium is presented. We found that the deuterium abundance at high energy is consistent with the hypothesis that the propagation mechanism of light nuclei is the same as that of heavier secondary components. C1 Univ Florence, Dipartimento Fis, I-50100 Florence, Italy. Sez INFN Firenze, I-50100 Florence, Italy. Univ Bari, Dipartimento Fis, I-70126 Bari, Italy. Sez INFN Bari, I-70126 Bari, Italy. Ist Nazl Fis Nucl, Lab Nazl, I-00044 Frascati, Italy. Alba Nova Univ Ctr, Royal Inst Technol KTH, S-10691 Stockholm, Sweden. Univ Trieste, Dipartimento Fis, I-34147 Trieste, Italy. Sez INFN Trieste, I-34147 Trieste, Italy. New Mexico State Univ, Las Cruces, NM 88003 USA. Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy. Sez INFN Roma, I-00133 Rome, Italy. Univ Siegen, D-57068 Siegen, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Ctr Rech Nucl, F-67037 Strasbourg, France. RP Vannuccini, E (reprint author), Univ Florence, Dipartimento Fis, Via G Sansone 1, I-50100 Florence, Italy. EM vannucci@fi.infn.it RI Morselli, Aldo/G-6769-2011; Cafagna, Francesco/A-9299-2010; Mocchiutti, Emiliano/I-8049-2013; Vacchi, Andrea/C-1291-2010; OI Boezio, Mirko/0000-0002-8015-2981; Morselli, Aldo/0000-0002-7704-9553; Cafagna, Francesco/0000-0002-7450-4784; Mocchiutti, Emiliano/0000-0001-7856-551X; Vacchi, Andrea/0000-0003-3855-5856; Bellotti, Roberto/0000-0003-3198-2708; casolino, marco/0000-0001-6067-5104; Sparvoli, Roberta/0000-0002-6314-6117; Picozza, Piergiorgio/0000-0002-7986-3321; Papini, Paolo/0000-0003-4718-2895 NR 46 TC 7 Z9 7 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 NOV 1 PY 2004 VL 615 IS 1 BP 259 EP 274 DI 10.1086/424027 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 866GB UT WOS:000224760800024 ER PT J AU Shelton, RL Kuntz, KD Petre, R AF Shelton, RL Kuntz, KD Petre, R TI G65.2+5.7: A thermal composite supernova remnant with a cool shell SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : individual (G65.2+5.7); supernova remnants; X-rays : ISM ID FORMED DENSE SHELL; X-RAY-EMISSION; NOVA REMNANT; MOLECULAR CLOUDS; HOT INTERIOR; MODELING W44; CYGNUS; G65.2&5.7; SPECTRUM; CONDUCTION AB This paper presents archival ROSAT PSPC observations of the G65.2+5.7 supernova remnant (also known as G65.3+5.7). Little material obscures this remnant, and so it was well observed, even at the softest end of ROSAT's bandpass (similar to0.11-0.28 keV). These soft X-ray images reveal the remnant's centrally filled morphology, which, in combination with existing radio frequency observations, places G65.2+5.7 in the thermal composite (mixed-morphology) class of supernova remnants. Not only might G65.2+5.7 be the oldest known thermal composite supernova remnant, but owing to its optically revealed cool, dense shell, this remnant supports the proposal that thermal composite supernova remnants lack X-ray-bright shells because they have evolved beyond the adiabatic phase. These observations also reveal a slightly extended point source centered on R. A. 19(h)36(m)46(s), decl. 30degrees40'07" and extending 6.'5 in radius in the band 67 map. The source of this emission has yet to be discovered, as there is no known pulsar at this location. C1 Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. Univ Georgia, Ctr Simulat Phys, Athens, GA 30602 USA. Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Shelton, RL (reprint author), Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. EM rls@hal.physast.uga.edu; kuntz@milkyway.gsfc.nasa.gov; rob@milkyway.gsfc.nasa.gov NR 34 TC 10 Z9 10 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 NOV 1 PY 2004 VL 615 IS 1 BP 275 EP 279 DI 10.1086/424029 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 866GB UT WOS:000224760800025 ER PT J AU Lovell, JEJ Moellenbrock, GA Horiuchi, S Fomalont, EB Scott, WK Hirabayashi, H Dodson, RG Dougherty, SM Edwards, PG Frey, S Gurvits, LI Lister, ML Murphy, DW Paragi, Z Piner, BG Shen, ZQ Taylor, AR Tingay, SJ Asaki, Y Moffett, D Murata, Y AF Lovell, JEJ Moellenbrock, GA Horiuchi, S Fomalont, EB Scott, WK Hirabayashi, H Dodson, RG Dougherty, SM Edwards, PG Frey, S Gurvits, LI Lister, ML Murphy, DW Paragi, Z Piner, BG Shen, ZQ Taylor, AR Tingay, SJ Asaki, Y Moffett, D Murata, Y TI The VSOP 5 GHz Active Galactic Nucleus Survey. II. Data calibration and imaging SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : active; radio continuum : galaxies; surveys; techniques : interferometric ID SPACE-OBSERVATORY PROGRAM; RADIO-SOURCES; AGN SURVEY; VLBI; CORRELATOR AB The VLBI Space Observatory Programme (VSOP) mission is a Japanese-led project to study radio sources with sub-milliarcsecond angular resolution using an orbiting 8 m telescope, HALCA, and global arrays of Earth-based telescopes. Approximately 25% of the observing time has been devoted to a survey of compact active galactic nuclei (AGNs) at 5 GHz that are stronger than 1 Jy-the VSOP AGN Survey. This paper, the second in a series, describes the data calibration, source detection, self-calibration, imaging, and modeling and gives examples illustrating the problems specific to space VLBI. The VSOP Survey Web site, which contains all results and calibrated data, is described. C1 CSIRO, Australia Telescope Natl Facil, Epping, NSW 2122, Australia. Natl Radio Astron Observ, Socorro, NM 87801 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Natl Astron Observ, Tokyo 1818588, Japan. Swinburne Univ Technol, Ctr Astrophys & Supercomp, Hawthorn, Vic 3122, Australia. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Univ Calgary, Dept Phys & Astron, Calgary, AB T2N 1N4, Canada. Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Dominion Radio Astrophys Observ, Penticton, BC V2A 6K3, Canada. FOMI Satellite Geodet Observ, H-1592 Budapest, Hungary. Joint Inst VLBI Europe, NL-7990 AA Dwingeloo, Netherlands. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Whittier Coll, Dept Phys & Astron, Whittier, CA 90608 USA. Shanghai Astron Observ, Shanghai 200030, Peoples R China. Furman Univ, Dept Phys, Greenville, SC 29613 USA. RP Lovell, JEJ (reprint author), CSIRO, Australia Telescope Natl Facil, POB 76, Epping, NSW 2122, Australia. RI Tingay, Steven/B-5271-2013; Frey, Sandor/G-4465-2013 OI Frey, Sandor/0000-0003-3079-1889 NR 19 TC 7 Z9 8 U1 1 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 NOV PY 2004 VL 155 IS 1 BP 27 EP 31 DI 10.1086/424820 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 865KC UT WOS:000224700400003 ER PT J AU Scott, WK Fomalont, EB Horiuchi, S Lovell, JEJ Moellenbrock, GA Dodson, RG Edwards, PG Coldwell, GV Fodor, S Frey, S Gurvits, LI Hirabayashi, H Lister, ML Mosoni, L Murata, Y Paragi, Z Piner, BG Shen, ZQ Taylor, AR Tingay, SJ AF Scott, WK Fomalont, EB Horiuchi, S Lovell, JEJ Moellenbrock, GA Dodson, RG Edwards, PG Coldwell, GV Fodor, S Frey, S Gurvits, LI Hirabayashi, H Lister, ML Mosoni, L Murata, Y Paragi, Z Piner, BG Shen, ZQ Taylor, AR Tingay, SJ TI The VSOP 5 GHz Active Galactic Nucleus Survey. III. Imaging results for the first 102 sources SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : active; radio continuum : galaxies; surveys ID REFERENCE FRAME SOURCES; SPACE-OBSERVATORY PROGRAM; SPECTRUM RADIO-SOURCES; QUASI-STELLAR OBJECTS; VLBA OBSERVATIONS; OPTICAL IDENTIFICATIONS; BL LACERTAE; ASTROMETRIC SUITABILITY; COMPLETE SAMPLE; EARTH ORBIT AB The VLBI Space Observatory Programme (VSOP) mission is a Japanese-led project to study radio sources with sub-milliarcsec resolution using an orbiting 8 m telescope, HALCA, along with global arrays of Earth-based telescopes. Approximately 25% of the observing time is devoted to a survey of compact active galactic nuclei (AGNs) that are stronger than 1 Jy at 5 GHz-the VSOP AGN Survey. This paper, the third in the series, presents the results from the analysis of the first 102 Survey sources. We present high-resolution images and plots of visibility amplitude versus projected baseline length. In addition, model-fit parameters to the primary radio components are listed, and from these the angular size and brightness temperature for the radio cores are calculated. For those sources for which we were able to determine the source frame core brightness temperature, a significant fraction (53 out of 98) have a source frame core brightness temperature in excess of 10(12) K. The maximum source frame core brightness temperature we observed was 1.2x10(13) K. Explaining a brightness temperature this high requires an extreme amount of relativistic Doppler beaming. Since the maximum brightness temperature one is able to determine using only ground-based arrays is of the order of 10(12) K, our results confirm the necessity of using space VLBI to explore the extremely high brightness temperature regime. C1 Univ Calgary, Dept Phys & Astron, Calgary, AB T2N 1N4, Canada. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Natl Astron Observ Japan, Tokyo 1818588, Japan. Swinburne Univ Technol, Ctr Astrophys & Supercomp, Hawthorn, Vic 3122, Australia. CSIRO, Australia Telescope Natl Facil, Epping, NSW 2122, Australia. Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Tasmania, Sch Math & Phys, Hobart, Tas 7001, Australia. Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Univ Nacl Cordoba, Astron Observ, Grp Invest Astron Teor & Expt, RA-5000 Cordoba, Argentina. Whittier Coll, Dept Phys, Whittier, CA 90608 USA. FOMI Satellite Geodet Observ, H-1592 Budapest, Hungary. Joint Inst VLBI Europe, NL-7990 AA Dwingeloo, Netherlands. MTA Konkoly Observ, H-1525 Budapest, Hungary. Chinese Acad Sci, Natl Astron Observ, Shanghai Astron Observ, Shanghai 200030, Peoples R China. Acad Sinica, Inst Astron & Astrophys, Taipei 106, Taiwan. RP Scott, WK (reprint author), Univ Calgary, Dept Phys & Astron, 2500 Univ Dr NW, Calgary, AB T2N 1N4, Canada. EM bill@ras.ucalgary.ca; efomalon@nrao.edu; shoriuchi@astro.swin.edu.au; jim.lovell@csiro.au; gmoellen@nrao.edu; rdodson@vsop.isas.jaxa.jp; pge@vsop.isas.jaxa.jp; georgina@oac.uncor.edu; fodor_zie@yahoo.com; frey@sgo.fomi.hu; lgurvits@jive.nl; hirax@vsop.isas.jaxa.jp; mlister@nrao.edu; mosoni@konkoly.hu; murata@vsop.isas.jaxa.jp; zparagi@jive.nl; gpiner@whittier.edu; zshen@center.shao.ac.cn; russ@ras.ucalgary.ca; stingay@astro.swin.edu.au RI Tingay, Steven/B-5271-2013; Frey, Sandor/G-4465-2013 OI Frey, Sandor/0000-0003-3079-1889 NR 57 TC 28 Z9 30 U1 1 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 NOV PY 2004 VL 155 IS 1 BP 33 EP 72 DI 10.1086/424819 PG 40 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 865KC UT WOS:000224700400004 ER PT J AU Adelman, SJ Proffitt, CR Wahlgren, GM Leckrone, DS Dolk, L AF Adelman, SJ Proffitt, CR Wahlgren, GM Leckrone, DS Dolk, L TI Heavy element abundances in late-B and early-A stars. I. Co-added IUE spectra of HgMn stars SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE stars : abundances; stars : chemically peculiar; ultraviolet : stars ID MERCURY-MANGANESE STARS; COADDED DAO SPECTROGRAMS; LUPI PATHFINDER PROJECT; METALLIC-LINED STARS; CHI-LUPI; KAPPA-CANCRI; HR 7775; EFFECTIVE TEMPERATURES; OSCILLATOR-STRENGTHS; SURFACE GRAVITIES AB Very heavy elements (Pt, Au, Hg, Tl, and Bi) are found to be enhanced in the atmospheres of the chemically peculiar stars of the upper main sequence by up to a million times the solar system levels. Such enhancements are believed to result from atmospheric dynamics (i.e., diffusion) rather than scenarios that dredge up nuclear-processed material to the surface or transfer processed material between binary companions. However, the theoretical framework needs to be further constrained by observations beyond the realm of the spectral types for which such abundance enhancements are observed at optical wavelengths. The International Ultraviolet Explorer (IUE) satellite collected spectra of bright stars for which chemical peculiarities have been derived from ground-based data. For several elements the abundance enhancements have only been recently measured using Hubble Space Telescope data and have therefore not yet been exploited in the IUE data. We have initiated a program to analyze IUE high-dispersion spectra to more fully characterize the pattern of very heavy element enhancement for many mercury-manganese (HgMn) stars and to potentially extend the spectral class (effective temperature) boundaries over which these abundance anomalies are known to exist. The abundances of very heavy elements in chemically normal B and A-type stars provide a base level that may be compared with the solar system abundances. These early spectral type stars may therefore reveal clues for galactic chemical evolution studies since they were formed at a later epoch than the Sun in the history of the Galaxy. This first paper presents the motivation for the analyses to follow, outlines our spectral co-addition technique for IUE spectra, and discusses the choice of model atmospheres and the synthetic spectrum procedures, while initiating the study by highlighting the abundance of gold in several HgMn stars. C1 Dept Phys, Charleston, SC 29409 USA. Catholic Univ Amer, Dept Phys, IACS, Washington, DC 20064 USA. Comp Sci Corp, Sci Program, Baltimore, MD 21218 USA. Lund Univ, Lund Observ, S-22100 Lund, Sweden. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Adelman, SJ (reprint author), Dept Phys, 171 Moultrie St, Charleston, SC 29409 USA. EM adelmans@citadel.edu; proffitt@stsci.edu; glenn.wahlgren@astro.lu.se; dave.leckrone@nasa.gov; linus.dolk@astro.lu.se NR 75 TC 22 Z9 22 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 NOV PY 2004 VL 155 IS 1 BP 179 EP 189 DI 10.1086/424802 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 865KC UT WOS:000224700400012 ER PT J AU Evans, KF Wiscombe, WJ AF Evans, KF Wiscombe, WJ TI An algorithm for generating stochastic cloud fields from radar profile statistics SO ATMOSPHERIC RESEARCH LA English DT Article; Proceedings Paper CT Joint Assembly of the EGS/AGU/EUG CY APR 06-11, 2003 CL Nice, FRANCE SP EGS, AGU, EUG DE stochastic cloud models; tropical west Pacific; cumulus clouds; millimeter-wave radar ID SOLAR RADIATIVE-TRANSFER; INDEPENDENT PIXEL; MICROWAVE RADIOMETER; FLUXES; GEOMETRY; ASTEX; APPROXIMATION; ABSORPTION; ALBEDO AB An algorithm is described for generating stochastic three-dimensional (3D) cloud fields from time-height fields derived from vertically pointing radar. This model is designed to generate cloud fields that match the statistics of the input fields as closely as possible. The major assumptions of the algorithm are that the statistics of the fields are translationally invariant in the horizontal and independent of horizontal direction; however, the statistics do depend on height. The algorithm outputs 2D or 3D stochastic fields of liquid water content (LWC) and (optionally) effective radius. The algorithm is a generalization of the Fourier filtering methods often used for stochastic cloud models. The Fourier filtering procedure generates Gaussian stochastic fields from a "Gaussian" cross-correlation matrix, which is a function of a pair of heights and the horizontal distance (or "lag"). The Gaussian fields are nonlinearly transformed to give the correct LWC histogram for each height. The "Gaussian" cross-correlation matrix is specially chosen so that, after the nonlinear transformation, the cross-correlation matrix of the cloud mask fields approximately matches that derived from the input LWC fields. The cloud mask correlation function is chosen because the clear/ cloud boundaries are thought to be important for 3D radiative transfer effects in cumulus. The stochastic cloud generation algorithm is tested with 3 months of boundary layer cumulus cloud data from an 8.6-mm wavelength radar on the island of Nauru. Winds from a 915-MHz wind profiler are used to convert the radar fields from time to horizontal distance. Tests are performed comparing the statistics of 744 radar-derived input fields to the statistics of 100 2D and 3D stochastic output fields. The single-point statistics as a function of height agree nearly perfectly. The input and stochastic cloud mask cross-correlation matrices agree fairly well. The cloud fractions agree to within 0.005 (the total cloud fraction is 18%). The cumulative distributions of optical depth, cloud thickness, cloud width, and intercloud gap length agree reasonably well. In the future, this stochastic cloud field generation algorithm will be used to study domain-averaged 3D radiative transfer effects in cumulus clouds. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Climate & Radiat Branch, Greenbelt, MD 20771 USA. RP Evans, KF (reprint author), Univ Colorado, Program Atmospher & Ocean Sci, Boulder, CO 80309 USA. EM evans@nit.colorado.edu RI Wiscombe, Warren/D-4665-2012 OI Wiscombe, Warren/0000-0001-6844-9849 NR 28 TC 33 Z9 34 U1 0 U2 1 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 NOV-DEC PY 2004 VL 72 IS 1-4 BP 263 EP 289 DI 10.1016/j.atmosres.2004.03.016 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 878CV UT WOS:000225625000015 ER PT J AU Oreopoulos, L Chou, MD Khairoutdinov, M Barker, HW Cahalan, RF AF Oreopoulos, L Chou, MD Khairoutdinov, M Barker, HW Cahalan, RF TI Performance of Goddard earth observing system GCM column radiation models under heterogeneous cloud conditions SO ATMOSPHERIC RESEARCH LA English DT Article; Proceedings Paper CT Joint Assembly of the EGS/AGU/EUG CY APR 06-11, 2003 CL Nice, FRANCE SP EGS, AGU, EUG DE Goddard earth observing system; general circulation model; column radiation model ID AVERAGED SOLAR FLUXES; STRATOCUMULUS CLOUDS; GENERAL-CIRCULATION; UNRESOLVED CLOUDS; PARAMETERIZATION; APPROXIMATION; VARIABILITY; DEFINITION; ALBEDO AB We test the performance of the shortwave (SW) and longwave (LW) Column Radiation Models (CORAMs) of Chou and collaborators with heterogeneous cloud fields from a single-day global dataset produced by NCAR's Community Atmospheric Model (CAM) with a 2-D Cloud Resolving Model (CRM) installed in each column. The original SW version of the CORAM performs quite well compared to reference Independent Column Approximation (ICA) calculations for boundary fluxes (global error similar to 4 W m(-2) for reflected flux), largely due to the success of a combined overlap and cloud scaling parameterization scheme. The absolute magnitude of errors relative to ICA are even smaller (global error similar to 2 W m(-2) for outgoing flux) for the LW CORAM which applies similar overlap. The vertical distribution of heating and cooling within the atmosphere is also simulated quite well with daily averaged zonal errors always less than 0.3 K/day for SW and 0.6 K/day for LW heating (cooling) rates. The SW CORAM's performance improves by introducing a scheme that accounts for cloud inhomogeneity based on the Gamma Weighted Two Stream Approximation (GWTSA). These results suggest that previous studies demonstrating the inaccuracy of plane-parallel models may have unfairly focused on worst case scenarios, and that current radiative transfer algorithms in General Circulation Models (GCMs) may be more capable than previously thought in estimating realistic spatial and temporal averages of radiative fluxes, as long as they are provided with correct mean cloud profiles. However, even if the errors of our particular CORAMs are small, they seem to be systematic, and their impact can be fully assessed only with GCM climate simulations. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, JCET, Baltimore, MD 21228 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. Meteorol Serv Canada, Downsview, ON, Canada. RP NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 913, Greenbelt, MD 20771 USA. EM lazaros@climate.gsfc.nasa.gov RI Oreopoulos, Lazaros/E-5868-2012; Cahalan, Robert/E-3462-2012 OI Oreopoulos, Lazaros/0000-0001-6061-6905; Cahalan, Robert/0000-0001-9724-1270 NR 30 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0169-8095 EI 1873-2895 J9 ATMOS RES JI Atmos. Res. PD NOV-DEC PY 2004 VL 72 IS 1-4 BP 365 EP 382 DI 10.1016/j.atmosres.2004.03.025 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 878CV UT WOS:000225625000020 ER PT J AU Shapiro, BE Hucka, M Finney, A Doyle, J AF Shapiro, BE Hucka, M Finney, A Doyle, J TI MathSBML: a package for manipulating SBML-based biological models SO BIOINFORMATICS LA English DT Article AB MathSBML is a Mathematica package designed for manipulating Systems Biology Markup Language (SBML) models. It converts SBML models into Mathematica data structures and provides a platform for manipulating and evaluating these models. Once a model is read by MathSBML, it is fully compatible with standard Mathematica functions such as NDSolve (a differential-algebraic equations solver). MathSBML also provides an application programming interface for viewing, manipulating, running numerical simulations; exporting SBML models; and converting SBML models in to other formats, such as XPP, HTML and FORTRAN. By accessing the full breadth of Mathematica functionality, MathSBML is fully extensible to SBML models of any size or complexity. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Hertfordshire, Sci & Technol Res Ctr, Hatfield AL10 9AB, Herts, England. RP Shapiro, BE (reprint author), CALTECH, Jet Prop Lab, Mail Stop 126-347,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM bshapiro@caltech.edu RI Hucka, Michael/B-1896-2012 FU NIGMS NIH HHS [R01 GM070923] NR 10 TC 34 Z9 34 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD NOV 1 PY 2004 VL 20 IS 16 BP 2829 EP 2831 DI 10.1093/bioinformatics/bth271 PG 3 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 873AD UT WOS:000225250100039 PM 15087311 ER PT J AU Witting, DA Chambers, RC Bosley, KL Wainright, SC AF Witting, DA Chambers, RC Bosley, KL Wainright, SC TI Experimental evaluation of ontogenetic diet transitions in summer flounder (Paralichthys dentatus), using stable isotopes as diet tracers SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID NITROGEN; CARBON; LARVAE; FRACTIONATION; DELTA-N-15; DELTA-C-13; TURNOVER; GROWTH; SETTLEMENT; TISSUES AB We examined the rate of isotopic change of nitrogen (N) and carbon (C) and isotopic fractionation at two temperatures during several ontogenetic diet transitions in summer flounder (Paralichthys dentatus). We examined prefeeding larvae as they metabolize the maternal source of nutrition and evaluated three diet transitions in the early life stages of this species: (i) yolk dependency to first feeding on zooplankton, (ii) one zooplankton (rotifers) to another (Artemia), and (iii) zooplanktivory to piscivory. We used experimental results and simulations to contrast time- versus growth-based models for estimating parameters of isotopic change and fractionation. All rates of isotopic change were lowest for the transition between zooplanktivory and piscivory, most rapid for the transition from yolk dependency to first feeding, and generally lower at cooler temperatures. Estimates of fractionation were greater for N (2.8e-3.8e) than for C (0.23e-0.91e) but appeared to be unaffected by water temperature or fish life stage. Simulation results suggested that parameter estimates of isotopic change and fractionation may be compromised when growth rates are low unless sampling design is modified to address slow growth rates. We conclude that sampling strategy and the model used can influence the accuracy and precision of estimates of isotopic change and fractionation. C1 Howard Marine Sci Lab, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, Highlands, NJ 07732 USA. Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Fishery Resource Anal & Monitoring Div, Newport, OR 97365 USA. US Coast Guard Acad, New London, CT 06320 USA. RP Witting, DA (reprint author), Howard Marine Sci Lab, Natl Marine Fisheries Serv, NE Fisheries Sci Ctr, 74 Magruder Rd, Highlands, NJ 07732 USA. EM david.witting@noaa.gov NR 28 TC 26 Z9 27 U1 1 U2 11 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA, ONTARIO K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD NOV PY 2004 VL 61 IS 11 BP 2069 EP 2084 DI 10.1139/F04-156 PG 16 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA 898JO UT WOS:000227073300004 ER PT J AU Harstad, K Bellan, J AF Harstad, K Bellan, J TI Modeling of multicomponent homogeneous nucleation using continuous thermodynamics SO COMBUSTION AND FLAME LA English DT Article DE homogeneous multicomponent nucleation ID SURFACE-TENSION; HIGH-PRESSURE; N-PENTANOL; MIXTURES; BINARY; RATES; TUBE AB A theory of homogeneous nucleation in a multicomponent vapor is developed by combining classic nucleation and continuous thermodynamics concepts. The perfect gas equation of state is used in conjunction with this theory to obtain a model valid at low vapor pressures. The theory is applied to kerosenes used for fuels in aeronautics (Jet A, JP-7, and RP-1) at temperatures from 220 to 360 K and at vapor pressures up to 1 bar. The results show that although the overall nucleation trends regarding the dependency on vapor pressure and temperature are similar for all kerosenes, Jet A has a distinct behavior compared with JP-7 and RP-1. For all kerosenes, as pressure increases, the nucleus size rapidly decreases and is smallest at low temperatures. (C) 2004 The Combustion Institute. Published by Elsevier Inc. 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, Pasadena, CA 91109 USA. EM josette.bellan@jpl.nasa.gov NR 33 TC 4 Z9 5 U1 1 U2 5 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 NOV PY 2004 VL 139 IS 3 BP 252 EP 262 DI 10.1016/j.combustflame.2004.08.012 PG 11 WC Thermodynamics; Energy & Fuels; Engineering, Multidisciplinary; Engineering, Chemical; Engineering, Mechanical SC Thermodynamics; Energy & Fuels; Engineering GA 873LM UT WOS:000225281800007 ER PT J AU Raju, IS Phillips, DR Krishnamurthy, T AF Raju, IS Phillips, DR Krishnamurthy, T TI A radial basis function approach in the meshless local Petrov-Galerkin method for Euler-Bernoulli beam problems SO COMPUTATIONAL MECHANICS LA English DT Article DE meshless methods; MLPG method; beam problems; radial basis functions ID MLPG METHOD; THIN BEAMS; ELEMENT; PLATES AB A meshless local Petrov-Galerkin (MLPG) method that uses radial basis functions rather than generalized moving least squares (GMLS) interpolations to develop the trial functions in the study of Euler-Bernoulli beam problems is presented. The use of radial basis functions (RBF) in meshless methods is demonstrated for C-1 problems for the first time. This interpolation choice yields a computationally simpler method as fewer matrix inversions and multiplications are required than when GMLS interpolations are used. Test functions are chosen as simple weight functions as in the conventional MLPG method. Patch tests, mixed boundary value problems, and problems with complex loading conditions are considered. The radial basis MLPG method yields accurate results for deflections, slopes, moments, and shear forces, and the accuracy of these results is better than that obtained using the conventional MLPG method. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Lockheed Martin Space Operat, Hampton, VA USA. RP Raju, IS (reprint author), NASA, Langley Res Ctr, Mail Stop 240, Hampton, VA 23681 USA. EM ivatury.s.raju@nasa.gov NR 22 TC 13 Z9 13 U1 0 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0178-7675 J9 COMPUT MECH JI Comput. Mech. PD NOV PY 2004 VL 34 IS 6 BP 464 EP 474 DI 10.1007/s00466-004-0591-z PG 11 WC Mathematics, Interdisciplinary Applications; Mechanics SC Mathematics; Mechanics GA 872CS UT WOS:000225184500003 ER PT J AU Nielsen, EJ Lu, J Park, MA Darmofal, DL AF Nielsen, EJ Lu, J Park, MA Darmofal, DL TI An implicit, exact dual adjoint solution method for turbulent flows on unstructured grids SO COMPUTERS & FLUIDS LA English DT Article ID AERODYNAMIC DESIGN OPTIMIZATION; NAVIER-STOKES EQUATIONS; FUNCTIONAL OUTPUTS; ERROR ESTIMATION; MESHES; ADAPTATION; FORMULATION; ALGORITHM; SOLVERS AB An implicit algorithm for solving the discrete adjoint system based on an unstructured-grid discretization of the Navier-Stokes equations is presented. The method is constructed such that an adjoint solution exactly dual to a direct differentiation approach is recovered at each time step, yielding a convergence rate which is asymptotically equivalent to that of the primal system. The new approach is implemented within a three-dimensional unstructured-grid framework and results are presented for inviscid, laminar, and turbulent flows. Improvements to the baseline solution algorithm, such as line-implicit relaxation and a tight coupling of the turbulence model, are also presented. By storing nearest-neighbor terms in the residual computation, the dual scheme is computationally efficient, while requiring twice the memory of the flow solution. The current implementation allows for multiple right-hand side vectors, enabling simultaneous adjoint solutions for several cost functions or constraints with minimal additional storage requirements, while reducing the solution time compared to serial applications of the adjoint solver. The scheme is expected to have a broad impact on computational problems related to design optimization as well as error estimation and grid adaptation efforts. (C) 2004 Elsevier Ltd. All rights reserved. C1 NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA. MIT, Dept Aeronaut & Astronaut, Cambridge, MA 02139 USA. RP Nielsen, EJ (reprint author), NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, MS 128, Hampton, VA 23681 USA. EM eric.j.nielsen@nasa.gov NR 57 TC 51 Z9 51 U1 1 U2 6 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 NOV PY 2004 VL 33 IS 9 BP 1131 EP 1155 DI 10.1016/j.compfluid.2003.09.005 PG 25 WC Computer Science, Interdisciplinary Applications; Mechanics SC Computer Science; Mechanics GA 828QE UT WOS:000221987000002 ER PT J AU Waugh, DW Haine, TWN Hall, TM AF Waugh, DW Haine, TWN Hall, TM TI Transport times and anthropogenic carbon in the subpolar North Atlantic Ocean SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article DE tracers; transit time distribution; anthropogenic carbon; Labrador Sea Water; North Atlantic Ocean ID LABRADOR SEA-WATER; DEEP-WATER; CO2 UPTAKE; CIRCULATION; TRITIUM; TRACER; HE-3; AGE; TETRACHLORIDE; RATES AB Simultaneous measurements of chlorofluorocarbons (CFCs), tritium, and helium are used to estimate the first two moments of the surface-to-interior transit times within the subpolar North Atlantic Ocean. The observed relationships among the different tracers implies that the transit-time distributions are broad, with width Delta approximately equal to the mean age F, indicating that mixing plays an important role in transport over decadal timescales. These broad transit-time distributions are further shown to be consistent with the observed time variations of mid-depth tritium in the Newfoundland Basin and Northeastern Atlantic between 1972 and 1997. We use the transit-time distributions inferred from the tracers to estimate the distribution, and change over the last two decades, of anthropogenic carbon in the subpolar North Atlantic. The values obtained are smaller than previous estimates using methods that have assumed weak mixing, with largest differences occurring in the Newfoundland Basin and Northeastern Atlantic. In the case of the uptake over the last two decades our estimate is 20-30% less than estimates that neglect mixing and use pCFC ages as water mass ages. (C) 2004 Elsevier Ltd. All rights reserved. C1 Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 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 Waugh, Darryn/K-3688-2016 OI Waugh, Darryn/0000-0001-7692-2798 NR 58 TC 83 Z9 84 U1 2 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD NOV PY 2004 VL 51 IS 11 BP 1475 EP 1491 DI 10.1016/j.dsr.2004.06.011 PG 17 WC Oceanography SC Oceanography GA 871ID UT WOS:000225123100005 ER PT J AU Knowlton, K Rosenthal, JE Hogrefe, C Lynn, B Gaffin, S Goldberg, R Rosenzweig, C Civerolo, K Ku, JY Kinney, PL AF Knowlton, K Rosenthal, JE Hogrefe, C Lynn, B Gaffin, S Goldberg, R Rosenzweig, C Civerolo, K Ku, JY Kinney, PL TI Assessing ozone-related health impacts under a changing climate SO ENVIRONMENTAL HEALTH PERSPECTIVES LA English DT Article ID DAILY MORTALITY; AIR-POLLUTION; MODEL; QUALITY AB Climate change may increase the frequency and intensity of ozone episodes in future summers in the United States. However, only recently have models become available that can assess the impact of climate change on O-3 concentrations and health effects at regional and local scales that are relevant to adaptive planning. We developed and applied an integrated modeling framework to assess potential O-3-related health impacts in future decades under a changing climate. The National Aeronautics and Space Administration-Goddard Institute for Space Studies global climate model at 4degrees x 5degrees resolution was linked to the Penn State/National Center for Atmospheric Research Mesoscale Model 5 and the Community Multiscale Air Quality atmospheric chemistry model at 36 km horizontal grid resolution to simulate hourly regional meteorology and O-3 in five summers of the 2050s decade across the 31-county New York metropolitan region. We assessed changes in O-3-related impacts on summer mortality resulting from climate change alone and with climate change superimposed on changes in O-3 precursor emissions and population growth. Considering climate change alone, there was a median 4.5% increase in O-3-related acute mortality across the 31 counties. Incorporating O-3 precursor emission increases along with climate change yielded similar results. When population growth was factored into the projections, absolute impacts increased substantially. Counties with the highest percent increases in projected O-3 mortality spread beyond the urban core into less densely populated suburban counties. This modeling framework provides a potentially useful new tool for assessing the health risks of climate change. C1 Columbia Univ, Mailman Sch Publ Hlth, Dept Environm Hlth Sci, New York, NY 10032 USA. SUNY Albany, Atmospher Sci Res Ctr, Albany, NY 12222 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. New York State Dept Environm Conservat, Bur Air Res, Albany, NY USA. RP Knowlton, K (reprint author), Columbia Univ, Mailman Sch Publ Hlth, Dept Environm Hlth Sci, 60 Haven Ave,B-1, New York, NY 10032 USA. EM kmk47@columbia.edu RI Kinney, Patrick/H-7914-2012; OI Civerolo, Kevin/0000-0003-1536-2664 FU NIEHS NIH HHS [ES09089] NR 37 TC 124 Z9 130 U1 2 U2 25 PU US DEPT HEALTH HUMAN SCIENCES PUBLIC HEALTH SCIENCE PI RES TRIANGLE PK PA NATL INST HEALTH, NATL INST ENVIRONMENTAL HEALTH SCIENCES, PO BOX 12233, RES TRIANGLE PK, NC 27709-2233 USA SN 0091-6765 J9 ENVIRON HEALTH PERSP JI Environ. Health Perspect. PD NOV PY 2004 VL 112 IS 15 BP 1557 EP 1563 DI 10.1289/ehp.7163 PG 7 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA 869GX UT WOS:000224972500045 PM 15531442 ER PT J AU Viboud, C Pakdaman, K Boelle, PY Wilson, ML Myers, MF Valleron, AJ Pakdaman, K AF Viboud, C Pakdaman, K Boelle, PY Wilson, ML Myers, MF Valleron, AJ Pakdaman, K TI Association of influenza epidemics with global climate variability SO EUROPEAN JOURNAL OF EPIDEMIOLOGY LA English DT Article DE climate; disease outbreaks/statistics & numerical data; ecology; environment; influenza/epidemiology; influenza/morbidity; influenza/mortality ID NINO-SOUTHERN OSCILLATION; EL-NINO; INFECTIOUS-DISEASE; FEVER EPIDEMICS; BORNE DISEASE; MALARIA; FRANCE; IMPACT; MORTALITY; DYNAMICS AB The reasons for the seasonality and annual changes in the impact of influenza epidemics remain poorly understood. We investigated the covariations between a major component of climate, namely the El Nino Southern Oscillation (ENSO), and indicators of the impact of influenza, as measured by morbidity, excess mortality and viral subtypes collected in France during the period 1971-2002. We show that both the circulating subtype and the magnitude of ENSO are associated with the impact of influenza epidemics. Recognition of this association could lead to better understanding of the mechanisms of emergence of influenza epidemics. C1 Univ St Antoine, Inst Natl Sante & Rech Med, Unit 444, Ctr Hosp, F-75571 Paris 12, France. WHO Collaborating Ctr Elect Dis Surveillance, F-75571 Paris, France. Univ Michigan, Dept Epidemiol, Ann Arbor, MI 48109 USA. NASA, Goddard Space Flight Ctr, Human Hlth Initiat, Greenbelt, MD 20770 USA. RP Viboud, C (reprint author), NIH, Div Int Epidemiol & Populat Studies, Fogarty Int Ctr, 16 Ctr Dr, Bethesda, MD 20892 USA. EM viboudc@mail.nih.gov NR 40 TC 49 Z9 55 U1 0 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0393-2990 J9 EUR J EPIDEMIOL JI Eur. J. Epidemiol. PD NOV PY 2004 VL 19 IS 11 BP 1055 EP 1059 DI 10.1007/s10654-004-2450-9 PG 5 WC Public, Environmental & Occupational Health SC Public, Environmental & Occupational Health GA 881XH UT WOS:000225902300010 PM 15648600 ER PT J AU Jordan, PM Puri, A AF Jordan, PM Puri, A TI Noncausal effects arising from a Maxwell fluid model with negative relaxation SO EUROPEAN JOURNAL OF PHYSICS LA English DT Article ID LIQUIDS; EQUATIONS; ELASTICITY AB The physically unrealistic implications of negative relaxation in continuum mechanics is explored in the context of Stokes' first problem for Maxwell fluids. In addition, the electrodynamic analogue of negative relaxation is discussed and several lessons for students are presented. Lastly, two of Maxwell's important contributions to the physical sciences are noted. C1 USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. Univ New Orleans, Dept Phys, New Orleans, LA 70148 USA. RP Jordan, PM (reprint author), USN, Res Lab, Stennis Space Ctr, Code 7181, Stennis Space Ctr, MS 39529 USA. EM apuri@uno.edu NR 33 TC 2 Z9 2 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0143-0807 J9 EUR J PHYS JI Eur. J. Phys. PD NOV PY 2004 VL 25 IS 6 BP 829 EP 834 DI 10.1088/0143-0807/25/6/015 PG 6 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA 876FZ UT WOS:000225483400015 ER PT J AU Ooi, TK Engberg, RC Gilbert, JA Vaughan, RE Bower, MV AF Ooi, TK Engberg, RC Gilbert, JA Vaughan, RE Bower, MV TI Modal testing of a lightweight cementitious structure SO EXPERIMENTAL TECHNIQUES LA English DT Article C1 Univ Alabama, Dept Mech & Aerosp Engn, Huntsville, AL USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. USA, RDECOM, Lead Struct Engineer Methods Branch, Redstone Arsenal, AL USA. RP Ooi, TK (reprint author), Univ Alabama, Dept Mech & Aerosp Engn, Huntsville, AL USA. NR 2 TC 1 Z9 1 U1 0 U2 1 PU SOC EXPERIMENTAL MECHANICS PI BETHEL PA 7 SCHOOL STREET, BETHEL, CT 06801 USA SN 0732-8818 J9 EXP TECHNIQUES JI Exp. Tech. PD NOV-DEC PY 2004 VL 28 IS 6 BP 37 EP 40 DI 10.1111/j.1747-1567.2004.tb00192.x PG 4 WC Engineering, Mechanical; Mechanics; Materials Science, Characterization & Testing SC Engineering; Mechanics; Materials Science GA 877IU UT WOS:000225562600006 ER PT J AU Hshieh, FY Hirsch, DB Williams, JH Beeson, HD AF Hshieh, FY Hirsch, DB Williams, JH Beeson, HD TI Upper flammability limits of some organosilicon compounds SO FIRE AND MATERIALS LA English DT Article DE organosilicon compounds; tipper flammability limit; net heat of combustion AB This paper reports the upper flammability limits of 26 organosilicon compounds commonly used in the silicone industry and investigates the correlation between the upper flammability limit and the net heat of combustion. An empirical equation has been developed to predict the upper flammability limit of organosilicon compounds using the net heat of combustion. Copyright (C) 2004 John Wiley Sons, Ltd. C1 Honeywell Technol Solut Inc, NASA Johnson Space Ctr, White Sands Test Facil, Las Cruces, NM USA. RP Hshieh, FY (reprint author), Honeywell Technol Solut Inc, NASA Johnson Space Ctr, White Sands Test Facil, Las Cruces, NM USA. EM fhshieh@wstf.nasa.gov; jwilliams@wstf.nasa.gov; hbeeson@wstf.nasa.gov NR 9 TC 2 Z9 3 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0308-0501 J9 FIRE MATER JI Fire Mater. PD NOV-DEC PY 2004 VL 28 IS 6 BP 459 EP 465 DI 10.1002/fam.865 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 878HW UT WOS:000225638500004 ER PT J AU Emmett, RL Brodeur, RD Orton, PM AF Emmett, RL Brodeur, RD Orton, PM TI The vertical distribution of juvenile salmon (Oncorhynchus spp.) and associated fishes in the Columbia River plume SO FISHERIES OCEANOGRAPHY LA English DT Article DE Columbia River; depth distribution; diel; Pacific salmon; surface trawling; tides ID COHO SALMON; CHINOOK; TSHAWYTSCHA; MIGRATION; KISUTCH AB Simultaneous trawling at surface and at depth at one location off the Columbia River, Oregon, in June 2000 identified the depth distribution of juvenile salmonids and associated fishes. Juvenile salmon off the Columbia River were distributed primarily near the surface, within the upper 12 m. Highest densities of subyearling chinook salmon (Oncorhynchus tshawytscha) off the Columbia River were associated with high surface currents and decreasing tidal levels, with time of day possibly a co-factor. Densities of yearling chinook salmon increased with higher turbidity. Pacific herring (Clupea pallasi) was the most abundant and commonly caught forage fish, with density increasing at night, probably related to diel vertical migration. Catches of juvenile salmonids were not associated with catches of forage fishes. Daytime surface trawling appears to be an appropriate method for assessing the distribution and abundance of juvenile salmonids in marine habitats. C1 Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Newport, OR 97365 USA. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. RP Emmett, RL (reprint author), Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, Newport, OR 97365 USA. EM robert.emmett@noaa.gov NR 25 TC 39 Z9 39 U1 1 U2 4 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 1054-6006 J9 FISH OCEANOGR JI Fish Oceanogr. PD NOV PY 2004 VL 13 IS 6 BP 392 EP 402 DI 10.1111/j.1365-2419.2004.00294.x PG 11 WC Fisheries; Oceanography SC Fisheries; Oceanography GA 865TY UT WOS:000224727300004 ER PT J AU Lauth, RR Ianelli, J Wakefield, WW AF Lauth, RR Ianelli, J Wakefield, WW TI Estimating the size selectivity and catching efficiency of a survey bottom trawl for thornyheads, Sebastolobus spp. using a towed video camera sled SO FISHERIES RESEARCH LA English DT Article DE video camera sled; catching efficiency; size selectivity; survey trawl; line transect; catchability; stock assessment ID MAXIMUM-LIKELIHOOD; ABUNDANCE AB Data from a video camera sled and research survey trawl were used to estimate size-specific trawl selectivity for Sebastolobus spp. Sizes from the camera sled video were extracted using an oblique grid plane and image analysis software. Thornyhead mean densities were 3-5 times higher with the camera sled than the survey trawl. Experimental selectivity patterns failed to conform to traditional parametric selectivity functions so a new non-parametric model was derived. The estimates of catchability for 20-25 cm thornyheads were 0.25-0.75. Catchability estimates for thornyheads larger than 30 cm were much lower (<0.10). A reason for low catchability at larger sizes remains unclear but may be a size-dependent interaction with the trawl, an artifact caused by low sample size of large fish in the study area, an unresolved bias in the video measurement system, or any combination of these factors. Published by Elsevier B.V. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, RACE Div, Seattle, WA 98115 USA. NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, REFM Div, Seattle, WA 98115 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, FRAM Div,Newport Res Stn, Newport, OR 97365 USA. RP Lauth, RR (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, RACE Div, 7600 Sand Point Way NE,Bldg 4, Seattle, WA 98115 USA. EM bob.lauth@noaa.gov NR 31 TC 15 Z9 15 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD NOV PY 2004 VL 70 IS 1 BP 27 EP 37 DI 10.1016/j.fishres.2004.06.010 PG 11 WC Fisheries SC Fisheries GA 865SK UT WOS:000224722900003 ER PT J AU Lauth, RR Wakefield, WW Smith, K AF Lauth, RR Wakefield, WW Smith, K TI Estimating the density of thornyheads, Sebastolobus spp., using a towed video camera sled SO FISHERIES RESEARCH LA English DT Article DE video camera sled; line transect; oblique grid plane; fish movement; density estimates ID ABUNDANCE; ALTIVELIS; ALASCANUS; ROCKFISH; PACIFIC AB A video camera sled was used to obtain an independent estimate of the density of Sebastolobus spp. (thornyheads) at three different depths (450, 750, and 1150m) within a given space and time. Camera sled video footage was processed using an oblique grid plane and line transect methods. Thornyheads were randomly distributed across the seafloor within the sampling area, and variation in the dispersion over increasing spatial scales (10-1280m) and depths was not significant. Thornyhead density estimates were derived using the program Distance. Densities ranged from 344 to 1005 thornyheads km(-2) and CVs from 10 to 18%. Underlying assumptions necessary for obtaining unbiased density estimates using a camera sled and line transect sampling are discussed, including a methodology to account for fish movement in response to the camera sled. Published by Elsevier B.V. C1 NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, RACE Div, Seattle, WA 98115 USA. NOAA, Natl Marine Fisheries Serv, NW Fisheries Sci Ctr, FRAM Div,Newport Res Stn, Newport, OR 97365 USA. RP Lauth, RR (reprint author), NOAA, Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, RACE Div, 7600 Sand Point Way NE, Seattle, WA 98115 USA. EM bob.lauth@noaa.gov RI Bizzarro, Joseph/A-2988-2012 NR 20 TC 17 Z9 17 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0165-7836 J9 FISH RES JI Fish Res. PD NOV PY 2004 VL 70 IS 1 BP 39 EP 48 DI 10.1016/j.fishres.2004.06.009 PG 10 WC Fisheries SC Fisheries GA 865SK UT WOS:000224722900004 ER PT J AU Sabaka, TJ Olsen, N Purucker, ME AF Sabaka, TJ Olsen, N Purucker, ME TI Extending comprehensive models of the Earth's magnetic field with Orsted and CHAMP data SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE electromagnetic induction; geomagnetic secular variation; ionosphere; lithosphere; magnetic field of the Earth; magnetosphere ID GEOMAGNETIC-FIELD; SECULAR VARIATION; WAVELET ANALYSIS; JERKS; AUSTRALIA; IMPULSES; PARAMETER; ORIGIN; EPOCH; TIME AB A new model of the quiet-time, near-Earth magnetic field has been derived using a comprehensive approach, which includes not only POGO and Magsat satellite data, but also data from the Orsted and CHAMP satellites. The resulting model shows great improvement over its predecessors in terms of completeness of sources, time span and noise reduction in parameters. With its well separated fields and extended time domain of 1960 to mid-2002, the model is able to detect the known sequence of geomagnetic jerks within this frame and gives evidence for an event of interest around 1997. Because all sources are coestimated in a comprehensive approach, intriguing north-south features typically filtered out with other methods are being discovered in the lithospheric representation of the model, such as the S Atlantic spreading ridge and Andean subduction zone lineations. In addition, this lithospheric field exhibits significantly less noise than previous models as a result of improved data selection. The F-region currents, through which the satellites pass, are now treated as lying within meridional planes, as opposed to being purely radial. Results are consistent with those found previously for Magsat, but an analysis at Orsted altitude shows exciting evidence that the meridional currents associated with the equatorial electrojet likely close beneath the satellite. Besides the model, a new analysis technique has been developed to infer the portion of a model parameter state resolved by a particular data subset. This has proven very useful in diagnosing the cause of peculiar artefacts in the Magsat vector data, which seem to suggest the presence of a small misalignment bias in the vector magnetometer. C1 NASA, Goddard Space Flight Ctr, Raytheon, Geodynam Branch, Greenbelt, MD 20771 USA. Danish Space Res Inst, DK-2100 Copenhagen O, Denmark. RP Sabaka, TJ (reprint author), NASA, Goddard Space Flight Ctr, Raytheon, Geodynam Branch, Greenbelt, MD 20771 USA. EM sabaka@geomag.gsfc.nasa.gov RI Olsen, Nils/H-1822-2011; Sabaka, Terence/D-5618-2012 OI Olsen, Nils/0000-0003-1132-6113; NR 52 TC 246 Z9 273 U1 2 U2 17 PU WILEY-BLACKWELL PUBLISHING, INC PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD NOV PY 2004 VL 159 IS 2 BP 521 EP 547 DI 10.1111/j.1365-246X.2004.02421.x PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 864LH UT WOS:000224634500009 ER PT J AU Hansen, CJ Bolton, SJ Matson, DL Spilker, LJ Lebreton, JP AF Hansen, CJ Bolton, SJ Matson, DL Spilker, LJ Lebreton, JP TI The Cassini-Huygens flyby of Jupiter SO ICARUS LA English DT Article DE Jupiter; Cassini ID ELECTRONS AB The Cassini-Huygens spacecraft flew by Jupiter on December 30, 2000. The instruments aboard the spacecraft started making scientific observations three months earlier. Joint, collaborative observations were carried out with the teams of other spacecraft, notably Galileo, and with Earth-based observers. An operational overview of the flyby is presented and attention drawn to contributions of the eleven papers of this series which follow. Prime achievements of this campaign have been to better define the present state of fundamental elements of the jovian system, confirming many previously tentative conclusions. Particularly noteworthy is that the interactions between the solar wind and the jovian magnetosphere have been explored far deeper than before, along with the link to the morphology and dynamics of the jovian aurora. (C) 2004 Elsevier Inc. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. European Space Agcy, Estec, Dept Space Sci, NL-2200 AG Noordwijk, Netherlands. RP Hansen, CJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop169-237, Pasadena, CA 91109 USA. EM candice.j.hansen@jpl.nasa.gov NR 21 TC 1 Z9 1 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 NOV PY 2004 VL 172 IS 1 BP 1 EP 8 DI 10.1016/j.icarus.2004.06.018 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869HK UT WOS:000224973800001 ER PT J AU Li, L Ingersoll, AP Vasavada, AR Porco, CC Del Genio, AD Ewald, SP AF Li, L Ingersoll, AP Vasavada, AR Porco, CC Del Genio, AD Ewald, SP TI Life cycles of spots on Jupiter from Cassini images SO ICARUS LA English DT Article DE atmospheres; dynamics; Jupiter; atmosphere; meteorology ID GREAT RED SPOT; MEAN ZONAL FLOW; JOVIAN ATMOSPHERE; MOIST CONVECTION; CLOUD STRUCTURE; WHITE OVALS; VOYAGER-1; VELOCITY; VORTICES; SYSTEM AB Using the sequence of 70-day continuum-band (751 nm) images from the Cassini Imaging Science System (ISS), we record over 500 compact oval spots and study their relation to the large-scale motions. The similar to100 spots whose vorticity could be measured-the large spots in most cases-were all anticyclonic. We exclude cyclonic features (chaotic regions) because they do not have a compact oval shape, but we do record their interactions with spots. We distinguish probable convective storms from other spots because they appear suddenly, grow rapidly, and are much brighter than their surroundings. The distribution of lifetimes for spots that appeared and disappeared during the 70-day period follows a decaying exponential with time constant (mean lifetime) of 3.5 days for probable convective storms and 16.8 days for all other spots. Extrapolating the exponential beyond 70 days seriously underestimates the number of spots that existed for the entire 70-day period. This and other evidences (size, shape, distribution in latitude) suggest that these long-lived spots with lifetime larger than 70 days are from a separate population. The zonal wind profile obtained manually by tracking individual features (this study) agrees with that obtained automatically by correlating brightness variations in narrow latitude bands (Porco et al., 2003). Some westward jets have developed more curvature and some have developed less curvature since Voyager times, but the number of westward jets that violate the barotropic stability criterion is about the same. In the northern hemisphere the number of spots is greatest at the latitudes of the westward jets, which are the most unstable regions according to the barotropic stability criterion. During the 70-day observation period the Great Red Spot (GRS) absorbed nine westward-moving spots that originated in the South Equatorial Belt (SEB), where most of the probable convective storms originate. Although the probable convective storms do not directly transform themselves into westward-moving spots, their common origin in the SEB suggests that moist convection and the westward jet compose a system that has maintained the GRS over its long lifetime. (C) 2003 Elsevier Inc. All rights reserved. C1 CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. SW Res Inst, Boulder, CO 80302 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Li, L (reprint author), CALTECH, Div Geol & Planetary Sci, MS 150-21, Pasadena, CA 91125 USA. EM liming@gps.caltech.edu RI Del Genio, Anthony/D-4663-2012 OI Del Genio, Anthony/0000-0001-7450-1359 NR 23 TC 26 Z9 26 U1 1 U2 10 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 NOV PY 2004 VL 172 IS 1 BP 9 EP 23 DI 10.1016/j.icarus.2003.10.015 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869HK UT WOS:000224973800002 ER PT J AU Dyudina, UA Del Genio, AD Ingersoll, AP Porco, CC West, RA Vasavada, AR Barbara, JM AF Dyudina, UA Del Genio, AD Ingersoll, AP Porco, CC West, RA Vasavada, AR Barbara, JM TI Lightning on Jupiter observed in the H-alpha line by the Cassini imaging science subsystem SO ICARUS LA English DT Article DE Jupiter, atmospheres; atmospheres, composition; meteorology; spectroscopy ID CLOUD STRUCTURE; PLANETARY-ATMOSPHERES; GALILEO IMAGES; CONVECTION AB Night side images of Jupiter taken by the Cassini Imaging Science Subsystem (ISS) camera with the H-alpha filter reveal four lightning clusters; two of them are repeated observations of the same storm. All of these flashes are associated with storm clouds seen a few hours earlier on the day side of Jupiter. Some of the clouds associated with lightning do not extend to the upper troposphere. The repeated lightning observations taken 20 hr apart show that storm clouds, whose mean lifetime is similar to4 days, are electrically active during a large fraction of their lifetime. The optical power of the lightning detected with the H-alpha filter compared to the clear-filter power of Galileo lightning may indicate that the H-alpha line in the lightning spectrum is about ten times weaker than expected, consistent with a flat spectrum having no prominent H-alpha line. This may suggest that lightning is generated in atmospheric layers deeper than 5 bars. This, in turn, may suggest that the water abundance of the jovian interior is more than 1 x solar. Averaged over many flashes, the most powerful Cassini lightning storm emits 0.8 x 10(9) W in the H-alpha line, which implies 4 x 10(10) W of broadband optical power. This is 10 times more powerful than the most intense jovian lightning observed before by Voyager 2. (C) 2004 Elsevier Inc. All rights reserved. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. CALTECH, Pasadena, CA 91125 USA. Space Sci Inst, Boulder, CO 80301 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. RP Dyudina, UA (reprint author), NASA, Goddard Inst Space Studies, 2800 Broadway, New York, NY 10025 USA. EM ulyana@gps.caltech.edu RI Del Genio, Anthony/D-4663-2012 OI Del Genio, Anthony/0000-0001-7450-1359 NR 24 TC 30 Z9 30 U1 0 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 NOV PY 2004 VL 172 IS 1 BP 24 EP 36 DI 10.1016/j.icarus.2004.07.014 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869HK UT WOS:000224973800003 ER PT J AU Irwin, PGJ Parrish, P Fouchet, T Calcutt, SB Taylor, FW Simon-Miller, AA Nixon, CA AF Irwin, PGJ Parrish, P Fouchet, T Calcutt, SB Taylor, FW Simon-Miller, AA Nixon, CA TI Retrievals of jovian tropospheric phosphine from Cassini/CIRS SO ICARUS LA English DT Article DE Jupiter; atmosphere; atmospheres, composition; radiative transfer; infrared observations ID GREAT RED SPOT; NORTH EQUATORIAL BELT; ABSORPTION-SPECTRA; THERMAL STRUCTURE; CLOUD STRUCTURE; GAS-COMPOSITION; JUPITER; ATMOSPHERE; AMMONIA; SPECTROSCOPY AB On December 30th, 2000, the Cassini-Huygens spacecraft reached the perijove milestone on its continuing journey to the Saturnian System. During an extended six-month encounter, the Composite Infrared Spectrometer (CIRS) returned spectra of the jovian atmosphere, rings and satellites from 10-1400 cm(-1) (1000-7 mum) at a programmable spectral resolution of 0.5 to 15 cm(-1). The improved spectral resolution of CIRS over previous IR instrument-missions to Jupiter, the extended spectral range, and higher signal-to-noise performance provide significant advantages over previous data sets. CIRS global observations of the mid-infrared spectrum of Jupiter at medium resolution (2.5 cm(-1)) have been analysed both with a radiance differencing scheme and an optimal estimation retrieval model to retrieve the spatial variation of phosphine and ammonia fractional scale height in the troposphere between 60degreesS and 60degreesN at a spatial resolution of 6degrees. The ammonia fractional scale height appears to be high over the Equatorial Zone (EZ) but low over the North Equatorial Belt (NEB) and South Equatorial Belt (SEB) indicating rapid uplift or strong vertical mixing in the EZ. The abundance of phosphine shows a similar strong latitudinal variation which generally matches that of the ammonia fractional scale height. However while the ammonia fractional scale height distribution is to a first order symmetric in latitude, the phosphine distribution shows a North/South asymmetry at mid latitudes with higher amounts detected at 40degreesN than 40degreesS. In addition the data show that while the ammonia fractional scale height at this spatial resolution appears to be low over the Great Red Spot (GRS), indicating reduced vertical mixing above the similar to500 mb level, the abundance of phosphine at deeper levels may be enhanced at the northern edge of the GRS indicating upwelling. (C) 2003 Elsevier Inc. All rights reserved. C1 Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, College Pk, MD 20742 USA. RP Irwin, PGJ (reprint author), Univ Oxford, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. EM irwin@atm.ox.ac.uk RI Nixon, Conor/A-8531-2009; Simon, Amy/C-8020-2012; Fouchet, Thierry/C-6374-2017; OI Nixon, Conor/0000-0001-9540-9121; Simon, Amy/0000-0003-4641-6186; Fouchet, Thierry/0000-0001-9040-8285; Calcutt, Simon/0000-0002-0102-3170; Irwin, Patrick/0000-0002-6772-384X NR 32 TC 49 Z9 49 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 NOV PY 2004 VL 172 IS 1 BP 37 EP 49 DI 10.1016/j.icarus.2003.09.027 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869HK UT WOS:000224973800004 ER PT J AU Throop, HB Porco, CC West, RA Burns, JA Showalter, MR Nicholson, PD AF Throop, HB Porco, CC West, RA Burns, JA Showalter, MR Nicholson, PD TI The jovian rings: new results derived from Cassini, Galileo, Voyager, and Earth-based observations SO ICARUS LA English DT Article DE planetary rings; Jupiter; photometry; dust ID NEAR-INFRARED OBSERVATIONS; SATURNS F-RING; JUPITERS RING; PHOTOMETRY; PARTICLES; SYSTEM; SCATTERING; SATELLITES; EVOLUTION; SPECTRA AB Cassini's Imaging Science Subsystem (ISS) instrument took nearly 1200 images of the Jupiter ring system during the spacecraft's 6-month encounter with Jupiter (Porco et al., 2003, Science 299, 1541-1547). These observations constitute the most complete data set of the ring taken by a single instrument, both in phase angle (0.5degrees-120degrees at seven angles) and wavelength (0.45-0.93 mum through eight filters). The main ring was detected in all targeted exposures; the halo and gossamer rings were too faint to be detected above the planet's stray light. The optical depth and radial profile of the main ring are consistent with previous observations. No broad asymmetries within the ring were seen; we did identify possible hints of 1000 km-scale azimuthal clumps within the ring. Cassini observations taken within 0.02degrees of the ring plane place an upper limit on the ring's full thickness of 80 km at a phase angle of 64degrees. We have combined the Cassini ISS and VIMS (Visible and Infrared Mapping Spectrometer) observations with those from Voyager, HST (Hubble Space Telescope), Keck, Galileo, Palomar, and IRTF (Infrared Telescope Facility). We have fit the entire suite of data using a photometric model that includes microscopic silicate dust grains as well as larger, long-lived 'parent bodies' that engender this dust. Our best-fit model to all the data indicates an optical depth of small particles of tau(s) = 4.7 x 10(-6) and large bodies tau(l) = 1.3 x 10(-6). The dust's cross-sectional area peaks near 15 mum. The data are fit significantly better using non-spherical rather than spherical dust grains. The parent bodies themselves must be very red from 0.4-2.5 mum, and may have absorption features near 0.8 and 2.2 mum. (C) 2004 Elsevier Inc. All rights reserved. C1 SW Res Inst, Boulder, CO 80302 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Stanford Univ, Space Telecommun & Radiosci Lab, Stanford, CA 94305 USA. RP Throop, HB (reprint author), SW Res Inst, 1050 Walnut St,Ste 400, Boulder, CO 80302 USA. EM throop@boulder.swri.edu NR 44 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 NOV PY 2004 VL 172 IS 1 BP 59 EP 77 DI 10.1016/j.icarus.2003.12.020 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869HK UT WOS:000224973800006 ER PT J AU McCord, TB Coradini, A Hibbitts, CA Capaccioni, F Hansen, GB Filacchione, G Clark, RN Cerroni, P Brown, RH Baines, KH Bellucci, G Bibring, JP Buratti, BJ Bussoletti, E Combes, M Cruikshank, DP Drossart, P Formisano, V Jaumann, R Langevin, Y Matson, DL Nelson, RM Nicholson, PD Sicardy, B Sotin, C AF McCord, TB Coradini, A Hibbitts, CA Capaccioni, F Hansen, GB Filacchione, G Clark, RN Cerroni, P Brown, RH Baines, KH Bellucci, G Bibring, JP Buratti, BJ Bussoletti, E Combes, M Cruikshank, DP Drossart, P Formisano, V Jaumann, R Langevin, Y Matson, DL Nelson, RM Nicholson, PD Sicardy, B Sotin, C TI Cassini VIMS observations of the Galilean satellites including the VIMS calibration procedure SO ICARUS LA English DT Article DE satellites; Galilean satellites; Jupiter system; satellite surfaces; surface composition; space mission ID INFRARED MAPPING SPECTROMETER; HYDRATED SALT MINERALS; SPECTRAL REFLECTANCE; SURFACE-STRUCTURE; EUROPAS SURFACE; PHASE CURVES; MU-M; GANYMEDE; CALLISTO; SPECTROSCOPY AB The Visual and Infrared Mapping Spectrometer (VIMS) observed the Galilean satellites during the Cassim spacecraft's 2000/2001 flyby of Jupiter, providing compositional and thermal information about their surfaces. The Cassini spacecraft approached the jovian system no closer than about 126 Jupiter radii, about 9 million kilometers, at a phase angle of < 90degrees, resulting in only sub-pixel observations by VIMS of the Galilean satellites. Nevertheless, most of the spectral features discovered by the Near Infrared Mapping Spectrometer (NIMS) aboard the Galileo spacecraft during more than four years of observations have been identified in the VIMS data analyzed so far, including a possible C-13 absorption. In addition, VIMS made observations in the visible part of the spectrum and at several new phase angles for all the Galilean satellites and the calculated phase functions are presented. In the process of analyzing these data, the VIMS radiometric and spectral calibrations were better determined in preparation for entry into the Saturn system. Treatment of these data is presented as an example of the VIMS data reduction, calibration and analysis process and a detailed explanation is given of the calibration process applied to the Jupiter data. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Hawaii, SOEST, HIGP, Honolulu, HI 96822 USA. Planetary Sci Inst, Winthrop, WA 98862 USA. CNR, Ist Fis Spazio Interplanetario, I-00133 Rome, Italy. US Geol Survey, Denver Fed Ctr, Denver, CO 80225 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Paris 11, IAS, F-91405 Orsay, France. Osserv Astron Capodimonte, INAF, I-80131 Naples, Italy. Dept Rech Spatial, F-92195XC Meudon, France. NASA, Ames Res Ctr, Astrophys Branch, Moffett Field, CA 94035 USA. Observ Meudon, F-92195 Meudon, France. DLR, Inst Planet Expl, D-12489 Berlin, Germany. Cornell Univ, Ithaca, NY 14853 USA. Univ Nantes, F-44072 Nantes 03, France. CNR, Ist Astrofis Spaziale & Fis Cosm, I-00133 Rome, Italy. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. RP McCord, TB (reprint author), Univ Hawaii, SOEST, HIGP, POST 502, Honolulu, HI 96822 USA. EM mccordtb@aol.com RI Hibbitts, Charles/B-7787-2016; OI Hibbitts, Charles/0000-0001-9089-4391; Bellucci, Giancarlo/0000-0003-0867-8679; Capaccioni, Fabrizio/0000-0003-1631-4314; Filacchione, Gianrico/0000-0001-9567-0055 NR 35 TC 47 Z9 47 U1 0 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 NOV PY 2004 VL 172 IS 1 BP 104 EP 126 DI 10.1016/j.icarus.2004.07.001 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869HK UT WOS:000224973800009 ER PT J AU Geissler, P McEwen, A Porco, C Strobel, D Saur, J Ajello, J West, R AF Geissler, P McEwen, A Porco, C Strobel, D Saur, J Ajello, J West, R TI Cassini observations of Io's visible aurorae SO ICARUS LA English DT Article DE Io; aurorae; satellites; atmospheres ID EXCITATION CROSS-SECTIONS; ELECTRON-IMPACT; ATOMIC OXYGEN; PLASMA TORUS; ATMOSPHERE; GALILEO; ULTRAVIOLET; EMISSION; ECLIPSE; FLUORESCENCE AB More than 500 images of to in eclipse were acquired by the Cassim spacecraft in late 2000 and early 2001 as it passed through the jovian system en route to Saturn (Porco et al., 2003, Science 299, 1541-1547). Io's bright equatorial glows were detected in Cassini's near-ultraviolet filters, supporting the interpretation that the visible emissions are predominantly due to molecular SO2. Detailed comparisons of laboratory SO2 spectra with the Cassini observations indicate that a mixture of gases contribute to the equatorial emissions. Potassium is suggested by new detections of the equatorial glows at near-infrared wavelengths from 730 to 800 nm. Neutral atomic oxygen and sodium are required to explain the brightness of the glows at visible wavelengths. The molecule S-2 is postulated to emit most of the glow intensity in the wavelength interval from 390 to 500 nm. The locations of the visible emissions vary in response to the changing orientation of the external magnetic field, tracking the tangent points of the jovian magnetic field lines. Limb glows distinct from the equatorial emissions were observed at visible to near-infrared wavelengths from 500 to 850 nm, indicating that atomic O, Na, and K are distributed across to's surface. Stratification of the atmosphere is demonstrated by differences in the altitudes of emissions at various wavelengths: SO2 emissions are confined to a region close to Io's surface, whereas neutral oxygen emissions are seen at attitudes that reach up to 900 km, or half the radius of the satellite. Pre-egress brightening demonstrates that light scattered into Jupiter's shadow by gases or aerosols in the giant planet's upper atmosphere contaminates images of to taken within 13 minutes of entry into or emergence from Jupiter's umbra. Although partial atmospheric collapse is suggested by the longer timescale for post-ingress dimming than pre-egress brightening, to's atmosphere must be substantially supported by volcanism to retain auroral emissions throughout the duration of eclipse. (C) 2004 Elsevier Inc. All rights reserved. C1 US Geol Survey, Flagstaff, AZ 86001 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. SW Res Inst, Dept Space Sci, Boulder, CO 80302 USA. Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Geissler, P (reprint author), US Geol Survey, 2255 N Gemini Dr, Flagstaff, AZ 86001 USA. EM pgeissler@usgs.gov NR 51 TC 36 Z9 36 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 NOV PY 2004 VL 172 IS 1 BP 127 EP 140 DI 10.1016/j.icarus.2004.01.008 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869HK UT WOS:000224973800010 ER PT J AU Bellucci, G D'Aversa, E Formisano, V Cruikshank, D Nelson, RM Clark, RN Baines, KH Matson, D Brown, RH McCord, TB Buratti, BJ Nicholson, PD AF Bellucci, G D'Aversa, E Formisano, V Cruikshank, D Nelson, RM Clark, RN Baines, KH Matson, D Brown, RH McCord, TB Buratti, BJ Nicholson, PD CA Cassini VIMS Team TI Cassini/VIMS observation of an Io post-eclipse brightening event SO ICARUS LA English DT Article DE Io; atmosphere; infrared observations; satellites of Jupiter ID INFRARED MAPPING SPECTROMETER; BIDIRECTIONAL REFLECTANCE SPECTROSCOPY; ALBEDO CHANGES; SEARCH; LO; CONDENSATION; ATMOSPHERE; NIGHTSIDE; JUPITER; VIMS AB During the Cassini-Jupiter flyby, VIMS observed Io at different phase angles, both in full sunlight and in eclipse. By using the sunlight measurements, we were able to produce phase curves in the visual through all the near infrared wavelengths covered by the VIMS instrument (0.85-5.1 mum). The phase angle spanned from similar to2degrees to similar to120degrees. The measurements, done just after To emerged from Jupiter's shadow, show an increase of about 15% in Io's reflectance with respect to what would be predicted by the phase curve. This behavior is observed at wavelengths > 1.2 mum. Moreover, just after emergence from eclipse an increase of about 25% is observed in the depth of SO2 frost bands at 4.07 and 4.35 mum. At 0.879 < lambda < 1.04 mum the brightening is 10-24%. Below lambda = 0.879 mum the brightening, if present, should be less than the precision of our measurements (similar to5%). Apparently, these observations are not explained neither by a diverse spatial distribution of SO2 on the Io' surface nor by atmospheric SO2 condensation on the surface during the eclipse. (C) 2004 Elsevier Inc. All rights reserved. C1 INAF, Ist Fis Spazio Interplanetario, I-00133 Rome, Italy. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. US Geol Survey, Denver, CO 80025 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Washington, Dept Earth & Space Sci, Seattle, WA 98195 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. RP Bellucci, G (reprint author), INAF, Ist Fis Spazio Interplanetario, Via Fosso Cavaliere 100, I-00133 Rome, Italy. EM giancarlo.bellucci@ifsi.rm.cnr.it OI Bellucci, Giancarlo/0000-0003-0867-8679; D'Aversa, Emiliano/0000-0002-5842-5867 NR 36 TC 5 Z9 5 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 NOV PY 2004 VL 172 IS 1 BP 141 EP 148 DI 10.1016/j.icarus.2004.05.012 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869HK UT WOS:000224973800011 ER PT J AU Simonelli, DP Buratti, BJ AF Simonelli, DP Buratti, BJ TI Europa's opposition surge in the near-infrared: interpreting disk-integrated observations by Cassini VIMS SO ICARUS LA English DT Article DE Cassini spacecraft; Europa; near-infrared; photometry ID BIDIRECTIONAL REFLECTANCE SPECTROSCOPY; ICY GALILEAN SATELLITES; COHERENT BACKSCATTER; SURFACE-STRUCTURE; PHOTOMETRY; MOON AB Near-infrared observations of Europa's disk-integrated opposition surge by Cassini VIMS, first published in Fig. 4 of Brown et al. (2003, Icarus, 164, 461), have now been modeled with the commonly used Hapke photometric function. The VIMS data set emphasizes observations at 16 solar phase angles from 0.4degrees to 0.6degrees - the first time the < 1degrees phase "heart" of Europa's opposition surge has been observed this well in the near-IR. This data set also provides a unique opportunity to examine how the surge is affected by changes in wavelength and albedo: at VIMS wavelengths of 0.91, 1.73, and 2.25 mum, the geometric albedo of Europa is 0.81, 0.33, and 0.18, respectively. Despite this factor-of-four albedo range, however, the slope of Europa's phase curve at < 1degrees phase is similar at all three wavelengths (to within the error bars) and this common slope is similar to the phase coefficient seen in visible-light observations of Europa. The two components of the opposition surge-involving different models of the physical cause of the surge-are the Shadow Hiding Opposition Effect (SHOE) and the Coherent Backscatter Opposition Effect (CBOE). Because of sparse VIMS phase coverage, it is not possible to constrain all the surge parameters at once in a Hapke function that has both SHOE and CBOE; accordingly, we performed separate Hapke fits for SHOE-only and CBOE-only surges. At 2.25 mum, where VIMS data are somewhat noisy, both types of surges can mimic the slope of the VIMS phase curve at < 1degrees phase. At 0.91 and 1.73 mum, however-where VIMS data are "cleaner"-CBOE does a noticeably poorer job than SHOE of matching the VIMS phase coefficient at < 1degrees phase; in particular, the best CBOE fit insists on having a steeper phase-curve slope than the data. This discrepancy suggests that Europa's near-IR opposition surge cannot be explained by CBOE alone and must have a significant SHOE component, even at wavelengths where Europa is bright. (C) 2004 Elsevier Inc. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Simonelli, DP (reprint author), CALTECH, Jet Prop Lab, MS 183-501,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM damon.p.simonelli@jpl.nasa.gov NR 26 TC 11 Z9 11 U1 2 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 NOV PY 2004 VL 172 IS 1 BP 149 EP 162 DI 10.1016/j.icarus.2004.06.004 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869HK UT WOS:000224973800012 ER PT J AU Shepard, MK Benner, LAM Ostro, SJ Campbell, DB Shapiro, II Chandler, JF AF Shepard, MK Benner, LAM Ostro, SJ Campbell, DB Shapiro, II Chandler, JF TI Radar detection of near-Earth Asteroids 1915 Quetzalcoatl, 3199 Nefertiti, 3757 (1982 XB), and 4034 (1986 PA) SO ICARUS LA English DT Article DE asteroids; radar ID MAIN-BELT; OBJECTS; PHOTOMETRY AB We describe Arecibo (2380 MHz, 12.6 cm) Doppler-only radar detections of near-Earth Asteroids 1915 Quetzalcoatl, 3199 Nefertiti, 3757 (1982 XB), and 4034 (1986 PA) obtained between 1981 and 1989. Estimates of the echo spectral bandwidths, radar cross-sections, and circular polarization ratios of these objects constrain their sizes, radar albedos, surface roughnesses, taxonomic classes, rotation periods, and pole directions. Our radar constraints on the diameters of Quetzalcoat1 and Nefertiti are most consistent with sizes determined using thermal-radiometry and the Fast Rotation Model (FRM); this consistency may indicate that these asteroids have surfaces of high thermal inertia (i.e., little or no regolith). Constraints on Quetzalcoatl's radar albedo rule out a "metallic M" classification. The radar constraints for Nefertiti are inconsistent with a rotation pole published by Kaasalainen et al. (2004, Icarus 167, 178). Our estimates of 1982 XB's size are consistent with previously published estimates. The radar bandwidth of 1986 PA places an upper bound of about 24 h on its rotation period. (C) 2004 Elsevier Inc. All rights reserved. C1 Bloomsburg Univ Penn, Dept Geog & Geosci, Bloomsburg, PA 17815 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Ithaca, NY 14853 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Shepard, MK (reprint author), Bloomsburg Univ Penn, Dept Geog & Geosci, Bloomsburg, PA 17815 USA. EM mshepard@bloomu.edu NR 28 TC 2 Z9 2 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 NOV PY 2004 VL 172 IS 1 BP 170 EP 178 DI 10.1016/j.icarus.2004.06.003 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 869HK UT WOS:000224973800014 ER PT J AU Filman, RE AF Filman, RE TI The interface space 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 2 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 NOV-DEC PY 2004 VL 8 IS 6 BP 4 EP 7 DI 10.1109/MIC.2004.1273478 PG 4 WC Computer Science, Software Engineering SC Computer Science GA 869HP UT WOS:000224974300001 ER PT J AU Watson, MD Ashley, PR Abushagur, MAG AF Watson, MD Ashley, PR Abushagur, MAG TI Modeling of optical waveguide poling and thermally stimulated discharge (TSD) charge and current densities for guest/host electro-optic polymers SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE electrode poling; guest/host polymer; Mach-Zehnder modulator; thermally stimulated discharge (TSD) current; waveguide ID MICROSCOPY; ELECTRETS AB A charge density and current density model of a waveguide system has been developed to explore the effects of electric field electrode poling. An optical waveguide is modeled during poling by considering the dielectric charge distribution, polarization charge distribution, and conduction charge generated by the poling field. The charge distributions are the source of poling current densities. The model shows that boundary charge current density and polarization current density are the major source of currents measured during poling and thermally stimulated discharge measurements. Charge distributions provide insight into the poling mechanisms and are directly related to E-A and alpha(r). Initial comparisons with experimental data show excellent correlation to the model results. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35812 USA. USA, AMRDEC, Huntsville, AL 35749 USA. Rochester Inst Technol, Kate Gleason Coll Engn, Rochester, NY 14623 USA. RP Watson, MD (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM Michael.D.Watson@nasa.gov; RR.Ashley@redstone.rdec.army.mil; maaeen@rit.edu NR 20 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 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD NOV PY 2004 VL 40 IS 11 BP 1555 EP 1561 DI 10.1109/JQE.2004.835116 PG 7 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 863MJ UT WOS:000224565700004 ER PT J AU Han, C Rodenbeck, C Huang, J Chang, K AF Han, C Rodenbeck, C Huang, J Chang, K TI A C/Ka dual frequency dual layer circularly polarized reflectarray antenna with microstrip ring elements SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE circular polarization; microstrip; reflectarray ID ARRAY ANTENNA; DESIGN AB This paper reports a dual frequency dual layer circularly polarized reffectarray operating, in the C and Ka bands. A 0.5-m right-hand circularly polarized planar refiectarray antenna is designed using microstrip ring elements of variable rotations to achieve a cophasal beam at broadside. The microstrip ring elements are more compact than the traditional rellectarray elements and can minimize blockage for the multilayer multifirequency applications. The highest efficiencies measured are 46% at 7.3 GHz and 38% at 31.75 GHz. The tested cross-polarization levels are -21 dB at 7.3 GHz and -29.2 dB at 31.75 GHz at the broadside direction. The tested results show that the designed ring element is suitable for both the single and dual layer applications with good bandwidth and circularly polarized performance. C1 Texas A&M Univ, Dept Elect Engn, College Stn, TX 77843 USA. Jet Prop Lab, Pasadena, CA 91109 USA. RP Han, C (reprint author), Texas A&M Univ, Dept Elect Engn, College Stn, TX 77843 USA. EM hcjfals@ee.tamu.edu; croden@ee.tamu.edu; jhuang@pop.jpl.nasa.gov; chang@ee.tamu.edu RI Rodenbeck, Christopher/A-8937-2009 NR 14 TC 53 Z9 55 U1 1 U2 10 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD NOV PY 2004 VL 52 IS 11 BP 2871 EP 2876 DI 10.1109/TAP.2004.835144 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 870JU UT WOS:000225054200007 ER PT J AU Hainkins, J AF Hainkins, J TI Accurate computation of the performance of M-ary orthogonal signaling on a discrete memoryless channel SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article DE optical modulation; optical signal detection; pulse-position modulation (PPM); signal detection AB A formula for the error rate of maximum-likelihood detection of M-ary orthogonal signaling on a discrete memoryless channel is manipulated into a form that avoids numerical imprecision when it is used to calculate low error rates. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hainkins, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM hamkins@jpl.nasa.gov NR 6 TC 6 Z9 7 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0090-6778 J9 IEEE T COMMUN JI IEEE Trans. Commun. PD NOV PY 2004 VL 52 IS 11 BP 1844 EP 1845 DI 10.1109/TCOMM.2004.836561 PG 2 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 870VC UT WOS:000225085700003 ER PT J AU Li, LF Simon, MK AF Li, LF Simon, MK TI Performance of coded OQPSK and MIL-STD SOQPSK with iterative decoding SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article DE bit-error rate (BER); iterative decoding; offset quadrature phase-shift keying (OQPSK); trellis-coded modulation (TCM) ID SERIAL CONCATENATION; DEMODULATION; MODULATION AB We show that military standard (MIL-STD) shaped-offset quadrature phase-shift keying (SOQPSK), a highly bandwidth-efficient constant-envelope modulation, can be represented in the form of a cross-correlated trellis-coded quadrature modulation. Similarly, we show that offset QPSK (OQPSK) can be decomposed into a "degraded" trellis encoder and a memoryless mapper. Based on the representations of OQPSK and MIL-STD SOQPSK as trellis-coded modulations (TCMs), we investigate the potential coding gains achievable from the application of simple outer codes to form a concatenated coding structure with iterative decoding. For MIL-STD SOQPSK, we describe the optimum receiver corresponding to its TCM form and then propose a simplified receiver. The bit-error rate (BER) performances of both receivers for uncoded and coded MIL-STD SOQPSK are simulated and compared with that of OQPSK and Feher-patented QPSK (FQPSK). The asymptotic BER performance of MIL-STD SOQPSK is also analyzed and compared with that of OQPSK and FQPSK. Simulation results show that, compared with their uncoded systems, there are significant coding gains for both OQPSK and MIL-STD SOQPSK, obtained by applying iterative decoding to either the parallel concatenated coding scheme or the serial one, even when very simple outer codes are used. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Li, LF (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM marvin.k.simon@jpl.nasa.gov NR 25 TC 33 Z9 39 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0090-6778 J9 IEEE T COMMUN JI IEEE Trans. Commun. PD NOV PY 2004 VL 52 IS 11 BP 1890 EP 1900 DI 10.1109/TCOMM.2004.836557 PG 11 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 870VC UT WOS:000225085700011 ER PT J AU Simon, MK Vilnrotter, VA AF Simon, MK Vilnrotter, VA TI Performance analysis and tradeoffs for dual-pulse PPM on optical communication channels with direct detection SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article DE direct detection; multipulse position modulation (MPPM); optical communications; photon counting AB The performance and tradeoffs of multipulse position modulation (MPPM) are investigated and compared with that of the traditional (single) pulse position modulation (PPM) scheme typically employed on the optical direct-detection channel. While the primary motivation for the consideration of the problem is to provide performance improvement for deep-space optical communications where narrow high-peak-power transmitted pulses offer significant advantages in terms of detection probabilities and background suppression capabilities at the receiver, the results obtained are sufficiently generic as to apply to other applications. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM victor.vilnrotter@jpl.nasa.gov NR 7 TC 17 Z9 21 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0090-6778 EI 1558-0857 J9 IEEE T COMMUN JI IEEE Trans. Commun. PD NOV PY 2004 VL 52 IS 11 BP 1969 EP 1979 DI 10.1109/TCOMM.2004.836554 PG 11 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 870VC UT WOS:000225085700019 ER PT J AU Dufrene, B Akarvardar, K Cristoloveanu, S Blalock, BJ Gentil, P Kolawa, E Mojarradi, MM AF Dufrene, B Akarvardar, K Cristoloveanu, S Blalock, BJ Gentil, P Kolawa, E Mojarradi, MM TI Investigation of the four-gate action in G(4)-FETs SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE JFET; MOSFET; multiple-gate transistor; silicon-on-insulator (SOI) ID TRANSISTORS; MOSFETS AB The four-gate silicon-on-insulator transistor (G(4)-FET) combines MOS and JFET actions in a single transistor to control the drain current. The various operation modes of the G(4)-FET are analyzed based on the measured current-voltage, transconductance and threshold characteristics. The main parameters (threshold voltage, swing, mobility) are extracted and shown to be optimized for particular combinations of gate biasing. Numerical simulations are used, to clarify the role of volume or interface conduction mechanisms. Besides excellent performance (such as subthreshold swing and transconductance) and unchallenged flexibility, the new device has the unique feature to allow independent switching by its four separate gates, which inspires many innovative applications. C1 IBM Corp, Essex Jct, VT 05452 USA. Univ Tennessee, Dept Elect & Comp Engn, Knoxville, TN 37996 USA. ENSERG, IMEP, Inst Microelect Electromagnet & Photon, F-38016 Grenoble, France. Univ Tennessee, Dept Elect & Comp Engn, Knoxville, TN 37996 USA. CALTECH, Jet Prop Lab, Avion Equipment Sect, Pasadena, CA 91109 USA. RP Dufrene, B (reprint author), IBM Corp, Essex Jct, VT 05452 USA. EM akarvard@enserg.fr NR 8 TC 31 Z9 31 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD NOV PY 2004 VL 51 IS 11 BP 1931 EP 1935 DI 10.1109/TED.2004.836548 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 864TW UT WOS:000224656800024 ER PT J AU Levy, RC Remer, LA Kaufman, YJ AF Levy, RC Remer, LA Kaufman, YJ TI Effects of neglecting polarization on the MODIS aerosol retrieval over land SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE aerosol; land; Moderate Imaging Spectroradiometer (MODIS); polarization; radiative transfer ID RESOLUTION IMAGING SPECTRORADIOMETER; SATELLITE; CLIMATE; SYSTEM; EARTH; VALIDATION; INSTRUMENT; ATMOSPHERE; RADIATION; PRODUCT AB Reflectance measurements in the visible and infrared wavelengths, from the Moderate Resolution Imaging Spectroradiometer (MODIS), are used to derive aerosol optical thicknesses (AOTs) and aerosol properties over ocean and land surfaces, separately. Both algorithms employ radiative transfer (RT) code to create lookup tables, simulating the top-of-atmosphere (TOA) reflectance measured by the satellite. Whereas the algorithm over ocean uses a vector RT code that includes the effects of atmospheric polarization, the algorithm over land assumes scalar RT, thus neglecting polarization effects. In the red (0.66 mum) and infrared (2.12 mum) MODIS channels, scattering by molecules (Rayleigh scattering) is minimal. In these bands, the use of a scalar RT code is of sufficient accuracy to model TOA reflectance. However, in the blue (0.47 mum), the presence of larger Rayleigh scattering (optical thickness approaching 0.2) results in nonnegligible polarization. The absolute difference between vector- and scalar-calculated TOA reflectance, even in the presence of depolarizing aerosols, is large enough to lead to substantial errors in retrieved AOT. Using RT code that allows for both vector and scalar calculations, we examine the reflectance differences at the TOA, assuming discrete loadings of continental-type aerosol. We find that the differences in blue channel TOA reflectance (vector-scalar) may be greater than 0.01 such that errors in derived AOT may be greater than 0.1. Errors may be positive or negative, depending on the specific geometry, and tend to cancel out when averages over a large enough sample of satellite geometry. Thus, the neglect of polarization introduces little error into global and long-term averages, yet can produce very large errors on smaller scales and individual retrievals. As a result of this study, a future version of aerosol retrieval from MODIS over land will include polarization within the atmosphere. C1 Sci Syst & Applicat Inc, Lanham, MD 20771 USA. NASA, Goddard Space Flight Ctr, Natl Aeronaut & Space Adm, Lab Atmospheres, Greenbelt, MD 20771 USA. Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. RP Levy, RC (reprint author), Sci Syst & Applicat Inc, Lanham, MD 20771 USA. EM levy@climate.gsfc.nasa.gov; remer@climate.gsfc.nasa.gov; kaufman@climate.gsfc.nasa.gov RI Levy, Robert/M-7764-2013 OI Levy, Robert/0000-0002-8933-5303 NR 34 TC 35 Z9 40 U1 1 U2 6 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 NOV PY 2004 VL 42 IS 11 BP 2576 EP 2583 DI 10.1109/TGRS.2004.837336 PG 8 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 871YG UT WOS:000225171900021 ER PT J AU Hu, YX Wielicki, BA Yang, P Stackhouse, PW Lin, B Young, DF AF Hu, YX Wielicki, BA Yang, P Stackhouse, PW Lin, B Young, DF TI Application of deep convective cloud albedo observation to satellite-based study of the terrestrial atmosphere: Monitoring the stability of spaceborne measurements and asssessing absorption anomaly SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE absorption anomaly; albedo; deep convective cloud; instrument stability; radiative transfer ID SOLAR-RADIATION AB An objective method is developed to monitor the stability of spaceborne instruments, aimed at distinguishing climate trend from instrument drift in satellite-based climate observation records. This method is based on four-years of Clouds and the Earth's Radiant Energy System (CERES) broadband observations of deep convective cloud systems with cloud-top temperature lower than 205 K and with large optical depths. The implementation of this method to the CERES instrument stability analysis reveals that the monthly albedo distributions are practically the same for deep convective clouds with CERES measurements acquired from both the Tropical Rainfall Measuring Mission and Terra satellite platforms, indicating that CERES instruments are well calibrated and stable during both missions. Furthermore, with a nonlinear regression neural network narrowband-broadband conversion, this instrument-stability monitoring method can also be applied to narrowband instruments such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Visible Infrared Scanner (VIRS). The results show that the drifts associated with both VIRS and MODIS instruments are less than 1% during a four-year period. Since the CERES albedo measurements are highly accurate, the absorptance of these opaque clouds can be reliably estimated. The absorptions of these clouds from observations are around 25%, whereas the absorptions from theory can be as low as 18%, depending on ice cloud microphysics. C1 NASA Langley Res Ctr, Radiat & Aerosols Branch, Hampton, VA 23681 USA. NASA Langley Res Ctr, Atmospher Sci Competency, Hampton, VA 23681 USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. RP Hu, YX (reprint author), NASA Langley Res Ctr, Radiat & Aerosols Branch, Hampton, VA 23681 USA. EM yongxiang.hu-1@nasa.gov; bruce.a.wielicki@nasa.gov; pyang@ariel.met.tamu.edu RI Yang, Ping/B-4590-2011; Hu, Yongxiang/K-4426-2012 NR 13 TC 35 Z9 35 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 NOV PY 2004 VL 42 IS 11 BP 2594 EP 2599 DI 10.1109/TGRS.2004.834765 PG 6 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 871YG UT WOS:000225171900023 ER PT J AU Barsi, S Kassemi, M Alexander, JID AF Barsi, S Kassemi, M Alexander, JID TI Effects of void-induced convection on interface morphology and segregation during low-g solidification SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article DE solidification; microgravity; materials processing; segregation; thermocapillary convection; bubbles; numerical modeling ID MICROGRAVITY SOLIDIFICATION; CRYSTAL-GROWTH; GALLIUM-ARSENIDE; ALLOYS; MELT AB Recent microgravity experiments have been hampered by convection caused by unwanted voids and/or bubbles in the melt. In this work, a numerical model is developed to describe how thermocapillary convection generated by a void can affect a typical Bridgman solidification process in microgravity. The model is based on the quasi-steady Navier-Stokes equations for a Newtonian fluid coupled with the conservation equations for transport of energy and species. Numerical solutions for a variety of operating conditions indicate that void-generated thermocapillary convection can have a drastic effect on both interface morphology and solutal transport. (C) 2004 Elsevier Ltd. All rights reserved. C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. Case Western Reserve Univ, Dept Engn Mech, Cleveland, OH 44106 USA. RP Kassemi, M (reprint author), NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, 21000 Brookpk Rd,MS110-3, Cleveland, OH 44135 USA. EM mohammad.kassemi@grc.nasa.gov NR 18 TC 4 Z9 4 U1 1 U2 3 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 NOV PY 2004 VL 47 IS 23 BP 5129 EP 5137 DI 10.1016/j.ijheatmasstransfer.2004.05.024 PG 9 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 861WU UT WOS:000224450100016 ER PT J AU Shazly, M Prakash, V Draper, S AF Shazly, M Prakash, V Draper, S TI Mechanical behavior of Gamma-Met PX under uniaxial loading at elevated temperatures and high strain rates SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article DE Gamma-Met PX; dynamic compression tests; dynamic tensile tests; elevated temperature ID DUCTILE TRANSITION-TEMPERATURE; HOPKINSON PRESSURE BAR; INTERMETALLIC ALLOYS; TITANIUM ALUMINIDE; RATE SENSITIVITY; COMPRESSION; DEFORMATION; DEPENDENCE; PROGRESS; TENSION AB Gamma titanium aluminides have received considerable attention over the last decade. These alloys are known to have low density, good high temperature strength retention and good oxidation and corrosion resistance. However, poor ductility and low fracture toughness have been the key limiting factors in the full utilization of these alloys. More recently, a new generation of gamma titanium aluminide alloys, commonly referred to as Gamma-Met PX, has been developed by GKSS, Germany. These alloys have been observed to have superior strength and better oxidation resistance at elevated temperatures when compared with conventional gamma titanium aluminides. The present paper discusses results of a study to understand the uniaxial mechanical behavior in both compression and tension of Gamma-Met PX at elevated temperatures and high strain rates. The compression and tensile tests are conducted using a modified Split-Hopkinson Bar apparatus at test temperatures ranging from room temperature to 900 degreesC and strain rates of up to 3500 s(-1). Under uniaxial compression, in the temperature range from room to 600 degreesC, the flow stress is observed to be nearly independent of test temperature. However, at temperatures higher than 600 degreesC thermal softening is observed at all strain rates with the rate of thermal softening increasing dramatically between 800 and 900 degreesC. The room temperature tensile tests show negligible strain-rate dependence on both yield stress and flow stress. With an increase in test temperature from room to 900 degreesC, the material shows a drop in both yield and flow stress at all levels of plastic strain. However, the measured flow stress is still higher when compared to nickel based superalloys and other gamma titanium aluminides under similar test conditions. Also, no anomaly in yield stress is observed up to 900 degreesC. (C) 2004 Elsevier Ltd. All rights reserved. C1 Case Western Reserve Univ, Dept Mech & Aerosp Engn, Cleveland, OH 44106 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Prakash, V (reprint author), Case Western Reserve Univ, Dept Mech & Aerosp Engn, 10900 Euclid Ave, Cleveland, OH 44106 USA. EM prakash@mae.cwru.edu NR 41 TC 18 Z9 21 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD NOV PY 2004 VL 41 IS 22-23 BP 6485 EP 6503 DI 10.1016/j.ijsolstr.2004.05.014 PG 19 WC Mechanics SC Mechanics GA 857RN UT WOS:000224136100024 ER PT J AU Barmatz, M Zhong, F Shih, A AF Barmatz, M Zhong, F Shih, A TI Reanalysis of microgravity heat capacity measurements near the SF6 liquid-gas critical point SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE critical phenomena; heat capacity; liquid-gas critical point; microgravity ID VAPOR CRITICAL-POINT; CROSSOVER-BEHAVIOR; HE-3; RENORMALIZATION AB The earlier microgravity heat capacity measurements in SF6 by Haupt and Straub have been reanalyzed in this study. A simple power law as well as the minimal-subtraction renormalization (MSR) scheme were used to fit the measurements. In this paper the unexpected result that the SF6 heat capacity measurements appear to be within the asymptotic critical region all the way out to a reduced temperature | t| similar or equal to 10(-2) is presented. This conclusion is in contradiction with the smaller asymptotic region | t |< 1.6 x 10(-4) found in the original investigation. These heat capacity measurements were found to be inconsistent with renormalization group predictions using SF6 compressibility measurements. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Calif State Polytech Univ Pomona, Dept Mech Engn, Pomona, CA 91768 USA. RP Barmatz, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Martin.B.Barmatz@jpl.nasa.gov NR 13 TC 7 Z9 7 U1 0 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD NOV PY 2004 VL 25 IS 6 BP 1667 EP 1675 DI 10.1007/s10765-004-7728-3 PG 9 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 875RK UT WOS:000225439200003 ER PT J AU Das, G Kestler, H Clemens, H Bartolotta, PA AF Das, G Kestler, H Clemens, H Bartolotta, PA TI Sheet gamma TiAl: Status and opportunities SO JOM LA English DT Article ID MECHANICAL-PROPERTIES; ALLOYS AB Gamma TiAl alloys have attractive properties such as low density, high-temperature strength, and high modulus, oxidation, and burn resistance. As a result, these alloys have the potential to replace heavier superalloys in aircraft engine components. Gamma TiAl alloys were investigated in the 1950s but were too brittle for thermo-mechanical processing. However interest in this class of material rekindled with several U.S. aerospace programs: the National Aerospace Plane, the Integrated High Performance Turbine Engine Technology, and Enabling Propulsion Materials/High Speed Civil Transport, as well as German hypersonic technology programs. Intense metallurgical and metal processing research during the last two decades led to significant progress in this area. As a result, gamma TiAl alloys are now available in all conventional product forms: ingots, forgings, extrusions, and sheets. This article reviews the current status of sheet gamma TiAl technology and its future opportunities. C1 Pratt & Whitney, E Hartford, CT 06108 USA. Plansee Aktiengesell, Reutte, Austria. Montan Univ, Dept Phys Met & Mat Testing, Leoben, Austria. NASA, GRC, Cleveland, OH USA. RP Das, G (reprint author), Pratt & Whitney, 400 Main St, E Hartford, CT 06108 USA. EM gopal.das@pw.utc.com RI Clemens, Helmut/B-2866-2012; OI Clemens, Helmut/0000-0001-6473-671X NR 20 TC 37 Z9 45 U1 3 U2 23 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1047-4838 J9 JOM-US JI JOM PD NOV PY 2004 VL 56 IS 11 BP 42 EP 45 DI 10.1007/s11837-004-0251-y PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 871KE UT WOS:000225129600017 ER PT J AU Raney, DL Slominski, EC AF Raney, DL Slominski, EC TI Mechanization and control concepts for biologically inspired micro air vehicles SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA Guidance Navigation and Control Conference CY AUG 11-14, 2003 CL Austin, TX SP Amer Inst Aeronaut & Astronaut ID WING ROTATION; FLIGHT AB It is possible that micro air vehicle (MAV) designs of the future will exploit flapping flight to perform missions that require extreme agility, such as rapid flight beneath a forest canopy or within the confines of a building. Many of nature's most agile fliers generate flapping motions through resonant excitation of an aeroelastically tailored structure: muscle tissue is used to excite a vibratory mode of their flexible wing structure that creates propulsion and lift. A number of micro air vehicle concepts have been proposed that would operate in a similar fashion. An ongoing research activity is described in which mechanization and control concepts with application to resonant flapping MAVs are being explored. Structural approaches, mechanical design, sensing, and wingbeat control concepts inspired by hummingbirds, bats, and insects are examined. Experimental results from a testbed capable of generating vibratory wingbeat patterns that approximately match those exhibited by hummingbirds in hover, cruise, and reverse flight are presented. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Virginia Polytech Inst & State Univ, Blacksburg, VA 24061 USA. RP Raney, DL (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 27 TC 32 Z9 33 U1 3 U2 8 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 NOV-DEC PY 2004 VL 41 IS 6 BP 1257 EP 1265 DI 10.2514/1.5514 PG 9 WC Engineering, Aerospace SC Engineering GA 888FY UT WOS:000226360800001 ER PT J AU Saephan, S van Dam, CP Fremaux, CM DalBello, T AF Saephan, S van Dam, CP Fremaux, CM DalBello, T TI Simulation of flow about rotating forebodies at high angles of attack SO JOURNAL OF AIRCRAFT LA English DT Article ID NAVIER-STOKES PREDICTIONS; ROTOR; COMPUTATION; PROJECTILES; COMPONENTS; EQUATIONS; DYNAMICS AB A Reynolds-averaged Navier-Stokes flow solver is used to predict the forces and moments on forebody models at high angle-of-attack rotary conditions. Cases simulated using either a circular or square ogive at an angle of attack of 60 deg, freestrearn Mach number of 0.21, and Reynolds number based on body diameter of approximately two million are presented and compared against wind-tunnel data from rotary testing on generic forebody models conducted by NASA Langley Research Center and the Defence Research Agency in the United Kingdom. The simulations provide insight into the flow characteristics at steady rotary conditions. C1 Univ Calif Davis, Davis, CA 95616 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Toledo, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Saephan, S (reprint author), Univ Calif Davis, Davis, CA 95616 USA. EM ssaephan@ucdavis.edu; cpvandam@ucdavis.edu; Charles.M.Fremaux@nsas.gov; teryn@grc.nasa.gov NR 34 TC 4 Z9 4 U1 1 U2 3 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 NOV-DEC PY 2004 VL 41 IS 6 BP 1298 EP 1305 DI 10.2514/1.8984 PG 8 WC Engineering, Aerospace SC Engineering GA 888FY UT WOS:000226360800005 ER PT J AU Weaver, D McAlister, KW Tso, J AF Weaver, D McAlister, KW Tso, J TI Control of VR-7 dynamic stall by strong steady blowing SO JOURNAL OF AIRCRAFT LA English DT Article ID AIRFOIL AB An experiment was performed in a water tunnel on a Boeing-Vertol VR-7 airfoil to study the effects of tangential blowing over the upper surface. Blowing was applied at the quarter-chord location during sinusoidal pitching oscillations described by alpha = alpha(m) + 10 deg sin omegat. Results were obtained for a Reynolds number of 1 x 10(5), mean angles of 10 and 15 deg, reduced frequencies ranging from 0.005 to 0.15, and blowing rates from C-mu = 0.16 to 0.66. Unsteady lift, drag, and pitching moment loads are reported, along with fluorescent-dye flow visualizations. Strong steady blowing was found to prevent the bursting of the leading-edge separation bubble at several test points. When this occurred, the lift was increased significantly, stall was averted, and the shape of the moment response showed a positive damping in pitch. In almost all cases, steady blowing reduced the hysteresis amplitudes present in the loads, but the benefits diminished as the reduced frequency and mean angle of oscillation increased. A limited number of pulsed blowing cases indicated that for low blowing rates, the greatest gains were achieved at F+ = 0.9. C1 Lockheed Martin Missiles & Fire Control, Dallas, TX 75265 USA. NASA, Ames Res Ctr, Aeroflightdynam Directorate, Moffett Field, CA 94035 USA. Calif Polytech State Univ San Luis Obispo, San Luis Obispo, CA 93407 USA. RP Weaver, D (reprint author), Lockheed Martin Missiles & Fire Control, Dallas, TX 75265 USA. NR 20 TC 8 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 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD NOV-DEC PY 2004 VL 41 IS 6 BP 1404 EP 1413 DI 10.2514/1.4413 PG 10 WC Engineering, Aerospace SC Engineering GA 888FY UT WOS:000226360800017 ER PT J AU Cruden, BA Cassell, AM Hash, DB Meyyappan, M AF Cruden, BA Cassell, AM Hash, DB Meyyappan, M TI Residual gas analysis of a dc plasma for carbon nanofiber growth SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; NANOTUBES; NANOSTRUCTURES AB We report the analysis of a plasma enhanced chemical vapor deposition process for carbon nanofiber growth. A direct current (dc) plasma is employed with a mixture of acetylene and ammonia. Residual gas analysis is performed on the downstream plasma effluent to determine degrees of precursor dissociation and high molecular weight species formation. Results are correlated to growth quality obtained in the plasma as a function of dc voltage/power, gas mixture, and pressure. Behaviors in plasma chemistry are understood through application of a zero-dimensional model. (C) 2004 American Institute of Physics. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Cruden, BA (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM bcruden@mail.arc.nasa.gov NR 19 TC 13 Z9 13 U1 1 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD NOV 1 PY 2004 VL 96 IS 9 BP 5284 EP 5292 DI 10.1063/1.1779975 PG 9 WC Physics, Applied SC Physics GA 866UQ UT WOS:000224799300087 ER PT J AU Grenon, SM Hurwitz, S Sheynberg, N Xiao, XS Judson, B Ramsdell, CD Kim, C Cohen, RJ Williams, GH AF Grenon, SM Hurwitz, S Sheynberg, N Xiao, XS Judson, B Ramsdell, CD Kim, C Cohen, RJ Williams, GH TI Sleep restriction does not affect orthostatic tolerance in the simulated microgravity environment SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE renin-angiotensin-aldosterone system; autonomic function ID SHORT-DURATION SPACEFLIGHT; BED REST; CARDIOVASCULAR REGULATION; SYSTEM-IDENTIFICATION; CLINICAL-IMPLICATIONS; CIRCADIAN-RHYTHMS; INTOLERANCE; DEPRIVATION; HUMANS; PERFORMANCE AB Orthostatic intolerance (OI) is a major problem following spaceflight, and, during flight, astronauts also experience sleep restriction. We hypothesized that sleep restriction will compound the risk and severity of OI following simulated microgravity and exaggerate the renal, cardioendocrine, and cardiovascular adaptive responses to it. Nineteen healthy men were equilibrated on a constant diet, after which they underwent a tilt-stand test. They then completed 14-16 days of simulated microgravity [head-down tilt bed rest (HDTB)], followed by repeat tilt-stand test. During HDTB, 11 subjects were assigned to an 8-h sleep protocol (non-sleep restricted), and 8 were assigned to a sleep-restricted protocol with 6 h of sleep per night. During various phases, the following were performed: 24-h urine collections, hormonal measurements, and cardiovascular system identification. Development of presyncope or syncope defined OI. There was a significant decrease in time free of OI (P = 0.02) and an increase in OI occurrence (P = 0.06) after HDTB among all subjects. However, the increase in OI occurrence did not differ significantly between the two groups (P = 0.60). The two groups also experienced similar physiological changes with HDTB ( initial increase in sodium excretion; increased excretion of potassium at the end of HDTB; increase in plasma renin activity secretion without a change in serum or urine aldosterone). No significant change in autonomic function or catecholamines was noted. Simulated microgravity leads to increased OI, and sleep restriction does not additively worsen OI in simulated microgravity. Furthermore, conditions of sleep restriction and nonsleep restriction are similar with respect to renal, cardioendocrine, and cardiovascular responses to simulated microgravity. C1 Brigham & Womens Hosp, Div Endocrinol Hypertens & Diabet, Boston, MA 02115 USA. MIT, NASA, Ctr Quantitat Cardiovasc Physiol Modeling & Data, Harvard MIT Div Hlth Sci & Technol, Cambridge, MA 02139 USA. McGill Univ, Dept Cardiothorac Surg, Montreal, PQ H3G 1A4, Canada. RP Williams, GH (reprint author), Brigham & Womens Hosp, Div Endocrinol Hypertens & Diabet, 221 Longwood Ave, Boston, MA 02115 USA. EM gwilliams@partners.org FU NCRR NIH HHS [5M01 RR-2635] NR 34 TC 1 Z9 1 U1 0 U2 1 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD NOV PY 2004 VL 97 IS 5 BP 1660 EP 1666 DI 10.1152/japplphysiol.00328.2004 PG 7 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 860RV UT WOS:000224361700016 PM 15234956 ER PT J AU Meneghini, R Jones, JA Iguchi, T Okamoto, K Kwiatkowski, J AF Meneghini, R Jones, JA Iguchi, T Okamoto, K Kwiatkowski, J TI A hybrid surface reference technique and its application to the TRMM precipitation radar SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID PATH ATTENUATION; SPACEBORNE RADAR; SINGLE-FREQUENCY; MIRROR-IMAGE; TOGA COARE; RAIN-RATE; RETRIEVAL; AIRBORNE; SIMULATIONS; ALGORITHMS AB Satellite weather radars that operate at attenuating wavelengths require an estimate of path attenuation to reconstruct the range profile of rainfall. One such method is the surface reference technique (SRT), by which attenuation is estimated as the difference between the surface cross section outside the rain and the apparent surface cross section measured in rain. This and the Hitschfeld-Bordan method are used operationally to estimate rain rate using data from the precipitation radar (PR) aboard the Tropical Rainfall Measuring Mission (TRMM) satellite. To overcome some of the problems associated with the latest operational version of the SRT, a hybrid surface reference is defined that uses information from the along-track and cross-track variations of the surface cross sections in rain-free areas. Over ocean, this approach eliminates most of the discontinuities in the path-attenuation field. Self-consistency of the estimates is tested by processing the orbits backward as well as forward. Calculations from 2 weeks of PR data show that 90% of the rain events over ocean for which the SRT is classified as reliable or marginally reliable are such that the absolute difference between the forward and backward estimates is less than 1 dB. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. Natl Inst Informat & Commun Technol, Tokyo, Japan. Osaka Prefecture Univ, Osaka, Japan. George Mason Univ, Fairfax, VA 22030 USA. RP Meneghini, R (reprint author), NASA, Goddard Space Flight Ctr, Code 975, Greenbelt, MD 20771 USA. EM bob@neptune.gsfc.nasa.gov RI PMM, JAXA/K-8537-2016 NR 25 TC 48 Z9 48 U1 0 U2 2 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 NOV PY 2004 VL 21 IS 11 BP 1645 EP 1658 DI 10.1175/JTECH1664.1 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 870ZW UT WOS:000225099300001 ER PT J AU Lyster, PM Guo, J Clune, T Larson, JW AF Lyster, PM Guo, J Clune, T Larson, JW TI The computational complexity and parallel scalability of atmospheric data assimilation algorithms SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ANALYSIS SYSTEM; KALMAN FILTER; ECMWF IMPLEMENTATION; FORMULATION; REANALYSIS; 3D-VAR AB This paper quantifies the computational complexity and parallel scalability of two algorithms for four-dimensional data assimilation (4DDA) at NASA's Global Modeling and Assimilation Office (GMAO). The first, the Goddard Earth Observing System Data Assimilation System (GEOS DAS), uses an atmospheric general circulation model (GCM) and an observation-space-based analysis system, the Physical-Space Statistical Analysis System (PSAS). GEOS DAS is very similar to global meteorological weather forecasting data assimilation systems but is used at NASA for climate research. The second, the Kalman filter, uses a more consistent algorithm to determine the forecast error covariance matrix than does GEOS DAS. For atmospheric assimilation, the gridded dynamical fields typically have more than 106 variables; therefore, the full error covariance matrix may be in excess of a teraword. For the Kalman filter this problem will require petaflop s(-1) computing to achieve effective throughput for scientific research. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. Sci Applicat Int Corp, Gen Sci Operat, Beltsville, MD USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Lyster, PM (reprint author), NIH, Bldg 10, Bethesda, MD 20892 USA. EM lysterpe@nigms.nih.gov NR 40 TC 2 Z9 2 U1 1 U2 4 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 NOV PY 2004 VL 21 IS 11 BP 1689 EP 1700 DI 10.1175/JTECH1636.1 PG 12 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 870ZW UT WOS:000225099300005 ER PT J AU Meyers, VE Zayzafoon, M Gonda, SR Gathings, WE McDonald, JM AF Meyers, VE Zayzafoon, M Gonda, SR Gathings, WE McDonald, JM TI Modeled microgravity disrupts collagen I/integrin signaling during osteoblastic differentiation of human mesenchymal stem cells SO JOURNAL OF CELLULAR BIOCHEMISTRY LA English DT Article DE osteoblast; HARV; RCCS; collagen; FAK; MAPK; integrin ID FOCAL ADHESION KINASE; EXTRACELLULAR-MATRIX; GENE-EXPRESSION; PROTEIN-KINASE; PHOSPHATIDYLINOSITOL 3-KINASE; TRANSCRIPTION FACTOR; MC3T3-E1 CELLS; MAPK PATHWAYS; BONE; ACTIVATION AB Spaceflight leads to reduced bone mineral density in weight bearing bones that is primarily attributed to a reduction in bone formation. We have previously demonstrated severely reduced osteoblastogenesis of human mesenchymal stem cells (hMSC) following 7 days culture in modeled microgravity (MMG). One potential mechanism for reduced osteoblastic differentiation is disruption of type I collagen (Col I)-integrin interactions and reduced integrin signaling. Integrins are heterodimeric transmembrane receptors that bind extracellular matrix (ECM) proteins and produce signals essential for proper cellular function, survival, and differentiation. Therefore, we investigated the effects of MMG on integrin expression and function in hMSC. We demonstrate that 7 days of culture in MMG leads to reduced expression of the ECM protein, Col I. Conversely, MMG consistently increases Col I-specific alpha2 and P, integrin protein expression. Despite this increase in integrin subunit expression, autophosphorylation of adhesion-dependent kinases, focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (PYK2), is significantly reduced. Activation of Akt protein kinase (Akt) is unaffected by the reduction in FAK activation. However, reduced downstream signaling via the Ras-mitogen activated protein kinase (MAPK) pathway is evidenced by a reduction in Ras and extracellular signal-related protein kinase (ERK) activation. Taken together, our findings indicate that MMG decreases integrin/MAPK signaling, which likely contributes to the observed reduction in osteoblastogenesis. (C) 2004 Wiley-Liss, Inc. C1 Univ Alabama, Dept Pathol, Milwaukee, WI 53233 USA. NASA, Lyndon B Johnson Space Ctr, Cellular Biotechnol Program, Houston, TX 77058 USA. Univ Alabama, CMDS, Huntsville, AL 35899 USA. Vet Adm Med Ctr, Birmingham, AL 35233 USA. RP McDonald, JM (reprint author), Univ Alabama, Dept Pathol, 220 West Pavil,619 S 19th St, Milwaukee, WI 53233 USA. EM mcdonald@.uab.edu FU NIAMS NIH HHS [1R01AR50235-01A1] NR 46 TC 63 Z9 79 U1 1 U2 7 PU WILEY-LISS PI HOBOKEN PA DIV JOHN WILEY & SONS INC, 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0730-2312 J9 J CELL BIOCHEM JI J. Cell. Biochem. PD NOV 1 PY 2004 VL 93 IS 4 BP 697 EP 707 DI 10.1002/jcb.20229 PG 11 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 868SL UT WOS:000224933200008 PM 15660414 ER PT J AU Zheng, Y Waliser, DE Stern, WF Jones, C AF Zheng, Y Waliser, DE Stern, WF Jones, C TI The role of coupled sea surface temperatures in the simulation of the tropical intraseasonal oscillation SO JOURNAL OF CLIMATE LA English DT Article ID MADDEN-JULIAN OSCILLATION; OUTGOING LONGWAVE RADIATION; GENERAL-CIRCULATION MODEL; ASIAN SUMMER MONSOON; EXTREME PRECIPITATION EVENTS; NINO SOUTHERN OSCILLATION; WESTERN UNITED-STATES; EL-NINO; TIME SCALES; TOGA-COARE AB This study compares the tropical intraseasonal oscillation (TISO) variability in the Geophysical Fluid Dynamics Laboratory (GFDL) coupled general circulation model (CGCM) and the stand-alone atmospheric general circulation model (AGCM). For the AGCM simulation, the sea surface temperatures (SSTs) were specified using those from the CGCM simulation. This was done so that any differences in the TISO that emerged from the two simulations could be attributed to the coupling process and not to a difference in the mean background state. The comparison focused on analysis of the rainfall, 200-mb velocity potential, and 850-mb zonal wind data from the two simulations, for both summer and winter periods, and included comparisons to analogous diagnostics using NCEP-NCAR reanalysis and Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) rainfall data. The results of the analysis showed three principal differences in the TISO variability between the coupled and uncoupled simulations. The first was that the CGCM showed an improvement in the spatial variability associated with the TISO mode, particularly for boreal summer. Specifically, the AGCM exhibited almost no TISO variability in the Indian Ocean during boreal summer-a common shortcoming among AGCMs. The CGCM, on the other hand, did show a considerable enhancement in TISO variability in this region for this season. The second was that the wavenumber-frequency spectra of the AGCM exhibited an unrealistic peak in variability at low wavenumbers (1-3, depending on the variable) and about 3 cycles yr(-1) (cpy). This unrealistic peak of variability was absent in the CGCM, which otherwise tended to show good agreement with the observations. The third difference was that the AGCM showed a less realistic phase lag between the TISO-related convection and SST anomalies. In particular, the CGCM exhibited a near-quadrature relation between precipitation and SST anomalies, which is consistent with observations, while the phase lag was reduced in the AGCM by about 1.5 pentads (similar to1 week). The implications of the above results, including those for the notions of "perfect SST'' and "two tier'' experiments, are discussed, as are the caveats associated with the study's modeling framework and analysis. C1 SUNY Stony Brook, Marine Sci Res Ctr, Stony Brook, NY 11794 USA. Princeton Univ, Geophys Fluid Dynam Lab, Princeton, NJ 08544 USA. Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. RP Waliser, DE (reprint author), CALTECH, Jet Prop Lab, MS 183-505,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM duane.waliser@jpl.nasa.gov RI Zheng, Yangxing/B-7965-2013; Jones, Charles/I-4574-2012 OI Zheng, Yangxing/0000-0003-2039-1494; Jones, Charles/0000-0003-4808-6977 NR 96 TC 61 Z9 66 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 NOV PY 2004 VL 17 IS 21 BP 4109 EP 4134 DI 10.1175/JCLI3202.1 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 870ZT UT WOS:000225099000001 ER PT J AU Yang, S Lau, KM Yoo, SH Kinter, JL Miyakoda, K Ho, CH AF Yang, S Lau, KM Yoo, SH Kinter, JL Miyakoda, K Ho, CH TI Upstream subtropical signals preceding the Asian summer monsoon circulation SO JOURNAL OF CLIMATE LA English DT Article ID TROPOSPHERIC BIENNIAL OSCILLATION; SEA-SURFACE-TEMPERATURE; EURASIAN SNOW COVER; TROPICAL-WIDE TELECONNECTION; SPACE-TIME CLIMATE; INTERANNUAL VARIABILITY; SOUTHERN-OSCILLATION; TIBETAN PLATEAU; EL-NINO; 3-DIMENSIONAL PROPAGATION AB In this study, the authors address several issues with respect to the antecedent signals of the large-scale Asian summer monsoon that were earlier identified by Webster and Yang. In particular, they revisit the changes in the subtropical upper-tropospheric westerlies preceding the monsoon, depict the detailed structure of the monsoon's antecedent signals, and investigate the physical processes from the signals to the monsoon. They also explore the teleconnection of these signals to various large-scale climate phenomena and emphasize the importance of the upstream location of the signals relative to the Tibetan Plateau and the monsoon. Before a strong (weak) Asian summer monsoon, the 200-mb westerlies over subtropical Asia are weak (strong) during the previous winter and spring. A significant feature of these signals is represented by the variability of the Middle East jet stream whose changes are linked to the Arctic Oscillation, North Atlantic Oscillation, El Nino-Southern Oscillation, and other climate phenomena. When this jet stream intensifies and shifts southeastward, cold air intrudes frequently from eastern Europe into the Middle East and southwestern Asia. As a result, in subtropical Asia, snow and precipitation increase, the ground wetness increases, and surface temperature decreases. A strengthening Middle East jet stream is also accompanied by increases in both stationary wave activity flux and higher-frequency eddy activities. The Tibetan Plateau acts to block these westerly activities propagating eastward and increase the persistence of the low-temperature anomalies, which in turn prolongs the atmospheric signals from winter to spring. A strong link is found between the persistent low-temperature anomalies and the decrease in geopotential height over southern Asia, including the Tibetan Plateau, in spring. The latter indicates a late establishment of the South Asian high, and implies a delay in the atmospheric transition from winter to summer conditions and in the development of the summer monsoon. The preceding scenario for a strong Middle East jet stream and a weaker Asian monsoon can be applied accordingly for the discussion of the physical processes from a weak jet stream to a strong monsoon. The current results of the relationship between the extratropical process and Asian monsoon resemble several features of the tropical-extratropical interaction mechanism for the tropospheric biennial oscillation (TBO). While the role of tropical heating is emphasized in the TBO mechanism, compared to the variability of the sea surface temperature related to El Nino-Southern Oscillation, the extratropical process examined in this study is more strongly linked to the Asian summer monsoon. C1 NCEP NWS NOAA, Climate Predict Ctr, Camp Springs, MD 20746 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Seoul Natl Univ, Sch Earth & Environm Sci, Seoul, South Korea. Ctr Ocean Land Atmosphere Studies, Calverton, MD USA. RP Yang, S (reprint author), NCEP NWS NOAA, Climate Predict Ctr, 5200 Auth Rd,Rm 605, Camp Springs, MD 20746 USA. EM song.yang@noaa.gov RI Yang, Song/B-4952-2009; Ho, Chang-Hoi/H-8354-2015; Lau, William /E-1510-2012 OI Lau, William /0000-0002-3587-3691 NR 72 TC 66 Z9 77 U1 3 U2 24 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 NOV PY 2004 VL 17 IS 21 BP 4213 EP 4229 DI 10.1175/JCLI3192.1 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 870ZT UT WOS:000225099000008 ER PT J AU Beacom, JF Candia, J AF Beacom, JF Candia, J TI Shower power: isolating the prompt atmospheric neutrino flux using electron neutrinos SO JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS LA English DT Article DE cosmic rays; ultra high energy photons and neutrinos; neutrino detectors; neutrino and gamma astronomy ID HIGH-ENERGY NEUTRINOS; GAMMA-RAY ABSORPTION; MUON NEUTRINOS; SPECTRUM; MARKARIAN-421; DISTRIBUTIONS; SENSITIVITY; TELESCOPES; ASTRONOMY AB At high energies, the very steep decrease of the conventional atmospheric component of the neutrino spectrum should allow the emergence of even small and isotropic components of the total spectrum, indicative of new physics, provided that they are less steeply decreasing, as generically expected. One candidate is the prompt atmospheric neutrino flux, a probe of cosmic ray composition in the region of the knee as well as small-x QCD, below the reach of collider experiments. A second is the diffuse extragalactic background due to distant and unresolved AGNs and GRBs, a key test of the nature of the highest-energy sources in the universe. Separating these new physics components from the conventional atmospheric neutrino flux, as well as from each other, will be very challenging. We show that the charged-current electron neutrino 'shower' channel should be particularly effective for isolating the prompt atmospheric neutrino flux, and that it is more generally an important complement to the usually considered charged-current muon neutrino 'track' channel. These conclusions remain true even for the low prompt atmospheric neutrino flux predicted in a realistic cosmic ray scenario with heavy and varying composition across the knee (Candia and Roulet, 2003 J. Cosmol. Astropart. Phys. JCAP09(2003) 005). We also improve the corresponding calculation of the neutrino flux induced by cosmic ray collisions with the interstellar medium. C1 Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Natl Univ La Plata, Dept Fis, IFLP, RA-1900 La Plata, Argentina. Fermilab Natl Accelerator Lab, Dept Theoret Phys, Batavia, IL 60510 USA. RP Beacom, JF (reprint author), Ohio State Univ, Dept Phys, 174 W 18th Ave, Columbus, OH 43210 USA. EM beacom@mps.ohio-state.edu; candia@fisica.unlp.edu.ar OI Beacom, John/0000-0002-0005-2631; Candia, Julian/0000-0001-5793-8989 NR 82 TC 23 Z9 23 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 1475-7516 J9 J COSMOL ASTROPART P JI J. Cosmol. Astropart. Phys. PD NOV PY 2004 IS 11 AR 009 DI 10.1088/1475-7516/2004/11/009 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 876KB UT WOS:000225494200004 ER PT J AU Hanson, JM Jones, RE AF Hanson, JM Jones, RE TI Test results for entry guidance methods for space vehicles SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 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 ID TRAJECTORIES AB There are a number of approaches to advanced guidance and control that have the potential for achieving the goals of significantly increasing reusable launch vehicle (or any space vehicle that enters an atmosphere) safety and reliability and reducing the cost. This paper examines some approaches to entry guidance. An effort called Integration and Testing of Advanced Guidance and Control Technologies has recently completed a rigorous testing phase, where these algorithms faced high-fidelity vehicle models and were required to perform a variety of representative tests. The algorithm developers spent substantial effort improving the algorithm performance in the testing. This paper lists the test cases used to demonstrate that the desired results are achieved, shows an automated test scoring method that greatly reduces the evaluation effort required, and displays results of the tests. The primary contribution of the paper is to provide a quantitative comparison between the performance of five different entry guidance approaches. Results show a significant improvement over the current state of the art (shuttle-like guidance). The two best-scoring algorithm approaches show roughly equivalent results. Both can be expected to work well for future vehicle concepts. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Sverdrup Technol Inc, Huntsville, AL 35806 USA. RP Hanson, JM (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 11 TC 29 Z9 40 U1 0 U2 3 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 NOV-DEC PY 2004 VL 27 IS 6 BP 960 EP 966 DI 10.2514/1.10886 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 871QP UT WOS:000225148700005 ER PT J AU Bombardelli, C Lorenzini, EC Quadrelli, MB AF Bombardelli, C Lorenzini, EC Quadrelli, MB TI Retargeting dynamics of a linear tethered interferometer SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID SATELLITE AB The study deals with the issue of changing the plane of rotation (retargeting) of a linear kilometer-sized formation of two collectors and one combiner spacecraft connected by two tether arms. A control strategy is proposed that makes use of a pair of electrical thrusters located onboard two of the three spacecraft to redirect the angular momentum of the formation to a new target with an accuracy of a few arcseconds while keeping the angular momentum magnitude constant throughout the maneuver. The thruster profile is optimized to achieve a very smooth but relatively fast maneuver while maintaining the overall fuel consumption at a minimum level. The attitude dynamics of the formation are solved analytically based on a perturbation method, which allows calibrating the thrust profile for high-precision retargeting. A numerical model is employed to test the proposed strategy and to evaluate the influence of massive flexible tethers and external perturbations on the accuracy of the maneuver. Finally, the required propellant mass is evaluated with reference to envisioned space interferometry missions. C1 Univ Padua, Fac Engn, Ctr Interdipartimentale Studi & Attivita Spaziali, I-35131 Padua, Italy. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bombardelli, C (reprint author), Univ Padua, Fac Engn, Ctr Interdipartimentale Studi & Attivita Spaziali, I-35131 Padua, Italy. NR 10 TC 16 Z9 17 U1 1 U2 5 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 NOV-DEC PY 2004 VL 27 IS 6 BP 1061 EP 1067 DI 10.2514/1.2933 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 871QP UT WOS:000225148700015 ER PT J AU Cheng, SF Lubitz, P Zheng, Y Edelstein, AS AF Cheng, SF Lubitz, P Zheng, Y Edelstein, AS TI Effects of spacer layer on growth, stress and magnetic properties of sputtered permalloy film SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT International Symposium on Advanced Magnetic Technologies (ISAMT 2003) CY NOV 13-16, 2003 CL Acad Sinica, Inst Phys, Taipei, TAIWAN SP Taiwan Assoc Magnet Technol, Opto Elect & Syst Lab, ITRI HO Acad Sinica, Inst Phys DE permalloy film; film stress; film texture; stripe domain ID THIN-FILMS; 1/F NOISE; SENSORS AB A microelectromechanical (MEMS) flux concentrator (J. Appl. phys. 91 (2002) 7795), is a device that will minimize 1/ f noise in magnetic sensors by modulating the magnetic field at the position of the sensor. This requires high permeability and low stress permalloy (Py) films to be deposited on the MEMS flaps (J. Appl. phys. 91 (2002) 7795). Py (Ni80Fe20) films from 100 to 560 nm thick were deposited on Si substrates using DC magnetron sputtering. The effects of deposition conditions on the grain morphology, texture, stress and magnetic properties were studied. Lower sputtering pressure changes film stress from tension to compression and increases the <111> out of film plane texture, while higher power increases tension and texture. Neutral film stress was obtained with 100 W of sputtering power and 1.25 mTorr of Ar gas pressure. With increasing thickness, the Py film was found to develop a stripe-like domain configuration at low fields because of strong out-of-plane magnetic anisotropy. The critical thickness is around 180nm. This may be explained by a competition between planar demagnetization fields and columnar magnetic anisotropy. Adding 5 nm of Ta or Cr layer as spacer successfully broke up the continuity of the magnetic structure and allowed us to produce high-permeability films by fabricating (Ta/Py) or (Cr/Py) multilayer films with each Py layer thinner than the critical thickness. (C) 2004 Published by Elsevier B.V. C1 USN, Res Lab, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, QSS, Greenbelt, MD 20771 USA. USA, Res Lab, Adelphi, MD 20783 USA. RP Cheng, SF (reprint author), USN, Res Lab, Washington, DC 20375 USA. EM chengs@anvil.nrl.navy.mil NR 10 TC 20 Z9 20 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD NOV 1 PY 2004 VL 282 SI SI BP 109 EP 114 DI 10.1016/j.jmmm.2004.04.027 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 866ZF UT WOS:000224811200028 ER PT J AU Niiler, P Lee, DK Moisan, J AF Niiler, P Lee, DK Moisan, J TI Observed mechanisms of El Nino SST evolution in the Pacific SO JOURNAL OF MARINE RESEARCH LA English DT Article ID EQUATORIAL PACIFIC; TROPICAL PACIFIC; SURFACE-LAYER; WARM POOL; CURRENTS; BALANCE; WAVES; OCEAN AB Tropical Pacific Ocean SST and velocity observations are used to construct NINO3 and NINO4 area average, 20-year long interannual time series of local and advective convergences of thermal energy. The variability of the sum of these observed convergences in each region is balanced by the vertical convergence of thermal energy due to the latent surface flux (86% in NINO3; 84% in NINO4). The latitude scale of the El Nino SST anomalies is shown to be equal to the ratio of the poleward mean speed of water parcels to the time scale at which thermal energy is given back to the atmosphere by a negative SST feedback through latent heat flux anomaly. Simultaneous observations and analyses of velocity and SST underscore the importance of the time-mean, wind-driven, poleward circulation in the establishment of the patterns of El Nino/SST anomalies directly north and south of the Pacific equator. C1 Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Pusan Natl Univ, Pusan 609735, South Korea. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Wallops Flight Facil, Wallops Isl, VA 23337 USA. RP Niiler, P (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, 9500 Gilman Dr, La Jolla, CA 92093 USA. EM pniiler@ucsd.edu RI Moisan, John/B-8762-2016 OI Moisan, John/0000-0002-8078-8939 NR 20 TC 5 Z9 5 U1 0 U2 2 PU SEARS FOUNDATION MARINE RESEARCH PI NEW HAVEN PA YALE UNIV, KLINE GEOLOGY LAB, 210 WHITNEY AVENUE, NEW HAVEN, CT 06520-8109 USA SN 0022-2402 J9 J MAR RES JI J. Mar. Res. PD NOV PY 2004 VL 62 IS 6 BP 771 EP 786 DI 10.1357/0022240042880855 PG 16 WC Oceanography SC Oceanography GA 890JT UT WOS:000226508200002 ER PT J AU Leon, R Colon, JA Evans, KC Vu, DT Blaschke, V Bavarian, B Ogawa, ET Ho, PS AF Leon, R Colon, JA Evans, KC Vu, DT Blaschke, V Bavarian, B Ogawa, ET Ho, PS TI Void evolution and its dependence on segment length in Cu interconnects SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID ELECTROMIGRATION LIFETIME; RELIABILITY AB Void evolution during electromigration was studied by recording void nucleation, growth, and displacements at various intervals during thermal (240 degreesC and electrical stress tests (2 x 106 amps/cm(2)) of Cu interconnects. Structural data was collected for various serially arranged line segment lengths and correlated with resistance and increases in resistance due to electromigration-induced thinning and voiding. These results allowed determination of void growth rates in Cu interconnects. Void nucleation and growth show a clear dependence on segment length. Void formation did not occur at the via/interconnect interface, which improved interconnect reliability by allowing extensive voiding before catastrophic failure. C1 Jet Prop Lab, Pasadena, CA 91109 USA. Calif State Univ Northridge, Northridge, CA 91330 USA. Int SEMATECH, Austin, TX 78741 USA. Univ Texas, Austin, TX 78712 USA. RP Leon, R (reprint author), Jet Prop Lab, Pasadena, CA 91109 USA. NR 10 TC 1 Z9 1 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD NOV PY 2004 VL 19 IS 11 BP 3135 EP 3138 DI 10.1557/JMR.2004.0408 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 867LI UT WOS:000224843700002 ER PT J AU Steger, R Lin, K Adelstein, BD Kazerooni, H AF Steger, R Lin, K Adelstein, BD Kazerooni, H TI Design of a passively balanced spatial linkage haptic interface SO JOURNAL OF MECHANICAL DESIGN LA English DT Article AB This paper describes the design and implementation of a compact high fidelity desktop haptic interface that provides three-degree-of-freedom point-force interaction through a handheld pen-like stylus. The complete haptic device combines a spatial linkage, actuation, power amplification, and control electronics in a standalone package with a footprint similar to that of a notebook computer (33 cm x 25 cm x 10 cm). The spatial linkage is composed of one planar and two spherical subloops. Two versions of the spatial linkage were designed: a lightweight polycarbonate plastic version suitable for inexpensive mass production, and an aluminum and stainless steel linkage that offers greater reliability and higher stiffness. Both linkages were designed to be statically balanced over their full workspace. C1 Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Human Factors Res & Technol Div, Moffett Field, CA 94035 USA. RP Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. NR 23 TC 9 Z9 9 U1 0 U2 0 PU ASME PI NEW YORK PA TWO PARK AVE, NEW YORK, NY 10016-5990 USA SN 1050-0472 J9 J MECH DESIGN JI J. Mech. Des. PD NOV PY 2004 VL 126 IS 6 BP 984 EP 991 DI 10.1115/1.1798111 PG 8 WC Engineering, Mechanical SC Engineering GA 903EH UT WOS:000227407800008 ER PT J AU Krantz, T Cooper, C Townsend, D Hansen, B AF Krantz, T Cooper, C Townsend, D Hansen, B TI Increased surface fatigue lives of spur gears by application of a coating SO JOURNAL OF MECHANICAL DESIGN LA English DT Article ID DIAMOND-LIKE-CARBON; FILMS; STEEL; DEPOSITION; ABRASION; PERFORMANCE AB Hard coatings have potential for increasing gear surface fatigue lives. Experiments were conducted using gears both with and without a metal-containing, carbon-based coating. The gears were case-carburized AISI 9310 steel spur gears. Some gears were provided with the coating by magnetron sputtering. Lives were evaluated by accelerated life tests. For uncoated gears, all of 15 tests resulted in fatigue failure before completing 275 million revolutions. For coated gears, 11 of the 14 tests were suspended with no fatigue failure after 275 million revolutions. The improved life owing to the coating, approximately a sixfold increase, was a statistically significant result. C1 NASA, Glenn Res Ctr, Army Res Lab, Cleveland, OH USA. United Technol Res Ctr, E Hartford, CT USA. Townsend Engn, Westlake, OH USA. Sikorsky Aircraft, Stratford, CT USA. RP Krantz, T (reprint author), NASA, Glenn Res Ctr, Army Res Lab, MS 23-3,21000 Brookpk Rd, Cleveland, OH USA. EM Timothy.L.Krantz@grc.nasa.gov NR 42 TC 3 Z9 3 U1 0 U2 4 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 1050-0472 J9 J MECH DESIGN JI J. Mech. Des. PD NOV PY 2004 VL 126 IS 6 BP 1047 EP 1054 DI 10.1115/1.1799651 PG 8 WC Engineering, Mechanical SC Engineering GA 903EH UT WOS:000227407800015 ER PT J AU Jackson, DJ Hockney, GM AF Jackson, DJ Hockney, GM TI Detector efficiency limits on quantum improvement SO JOURNAL OF MODERN OPTICS LA English DT Article; Proceedings Paper CT 34th Winter Colloquium on the Physics of Quantum Electronics CY JAN 04-08, 2004 CL Snowbird, UT ID TIME AB Although the National Institute of Standards and Technology has measured the intrinsic quantum efficiency of Si and InGaAs avalanche photo diode (APD) materials to be above 98% by building an efficient compound detector, commercially available devices have efficiencies ranging between 15 and 75%. This means bandwidth, dark current, cost, and other factors are more important than quantum efficiency for existing applications. For non-classical correlated photon applications, the system's correlated signal-to-noise ratio is proportional to (etaN)(1/2)/(1 - eta)(1/2), rather than the classical signal-to-noise (etaN)(1/2). Consequently, the detector design trade space must be re-evaluated. This paper systematically examines the generic detection process, lays out the considerations needed for designing detectors for non-classical applications, and identifies the ultimate physical imits on quantum efficiency. C1 CALTECH, Jet Prop Lab, Quantum Comp Technol, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, Quantum Comp Technol, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM deborah.j.jackson@jpl.nasa.gov NR 16 TC 1 Z9 1 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0950-0340 EI 1362-3044 J9 J MOD OPTIC JI J. Mod. Opt. PD NOV-DEC PY 2004 VL 51 IS 16-18 SI SI BP 2429 EP 2440 DI 10.1080/09500340408231801 PG 12 WC Optics SC Optics GA 885MI UT WOS:000226160700009 ER PT J AU Smith, DD Chang, HR AF Smith, DD Chang, HR TI Coherence phenomena in coupled optical resonators SO JOURNAL OF MODERN OPTICS LA English DT Article; Proceedings Paper CT 34th Winter Colloquium on the Physics of Quantum Electronics CY JAN 04-08, 2004 CL Snowbird, UT ID TRANSPARENCY AB We predict a variety of photonic coherence phenomena in passive and active coupled ring resonators. Specifically, the effective dispersive and absorptive steady-state response of coupled resonators is derived, and used to determine the conditions for coupled-resonator-induced transparency and absorption, lasing without gain, and cooperative cavity emission. These effects rely on coherent photon trapping, in direct analogy with coherent population trapping phenomena in atomic systems. We also demonstrate that the coupled-mode equations are formally identical to the two-level atom Schrodinger equation in the rotating-wave approximation, and use this result for the analysis of coupled-resonator photon dynamics. Notably, because these effects are predicted directly from coupled-mode theory, they are not unique to atoms, but rather are fundamental to systems of coherently coupled resonators. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RP NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM david.d.smith@nasa.gov NR 18 TC 28 Z9 28 U1 0 U2 7 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0950-0340 EI 1362-3044 J9 J MOD OPTIC JI J. Mod. Opt. PD NOV-DEC PY 2004 VL 51 IS 16-18 SI SI BP 2503 EP 2513 DI 10.1080/09500340408231809 PG 11 WC Optics SC Optics GA 885MI UT WOS:000226160700017 ER PT J AU Matsko, AB Savchenkov, AA Strekalov, D Ilchenko, VS Maleki, L AF Matsko, AB Savchenkov, AA Strekalov, D Ilchenko, VS Maleki, L TI Interference effects in lossy resonator chains SO JOURNAL OF MODERN OPTICS LA English DT Article; Proceedings Paper CT 34th Winter Colloquium on the Physics of Quantum Electronics CY JAN 04-08, 2004 CL Snowbird, UT ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; MICRORING RESONATORS; FILTER RESPONSE; RING RESONATOR; SYSTEMS; SLOW; LINE AB We theoretically study properties of narrow spectral features occurring in chains of coupled optical resonators due to classical optical interference. We compare those properties with the properties of the phenomenon of electromagnetically induced transparency in quantum systems. Despite the difference in the underlying physics, we show that both types of systems show striking similarities in optical properties and in possible applications. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Matsko, Andrey/A-1272-2007 NR 29 TC 22 Z9 22 U1 1 U2 8 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0950-0340 EI 1362-3044 J9 J MOD OPTIC JI J. Mod. Opt. PD NOV-DEC PY 2004 VL 51 IS 16-18 SI SI BP 2515 EP 2522 DI 10.1080/09500340408231810 PG 8 WC Optics SC Optics GA 885MI UT WOS:000226160700018 ER PT J AU Strekalov, D Matsko, AB Yu, N Maleki, L AF Strekalov, D Matsko, AB Yu, N Maleki, L TI Influence of inhomogeneous broadening on group velocity in coherently pumped atomic vapour SO JOURNAL OF MODERN OPTICS LA English DT Article; Proceedings Paper CT 34th Winter Colloquium on the Physics of Quantum Electronics CY JAN 04-08, 2004 CL Snowbird, UT ID LIGHT; SLOW AB We studied experimentally the influence of thermal atomic motion on light propagation in a vacuum atomic vapour cell above room temperature. We found that atomic motion introduces sizable changes in the spectral properties of the medium, such as dispersion and absorption, if the conditions for coherent population trapping are fulfilled. In particular, studying the group delay of light in the atomic vapour, we confirm the theoretical predictions of Kocharovskaya et al. (2001, Phys. Rev. Lett., 86, 628) and demonstrate that a coherent atomic medium has light dragging abilities large enough to make feasible the realization of frozen light based on atomic motion. We also demonstrate that dragging can be observed in measurements of the electromagnetically induced transparency resonance width, as well as in group delay measurements. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM dmitry.v.strekalov@jpl.nasa.gov RI Matsko, Andrey/A-1272-2007 NR 8 TC 2 Z9 2 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0950-0340 EI 1362-3044 J9 J MOD OPTIC JI J. Mod. Opt. PD NOV-DEC PY 2004 VL 51 IS 16-18 SI SI BP 2571 EP 2578 DI 10.1080/09500340408231815 PG 8 WC Optics SC Optics GA 885MI UT WOS:000226160700023 ER PT J AU Chuang, HF Cooper, SM Meyyappan, M Cruden, BA AF Chuang, HF Cooper, SM Meyyappan, M Cruden, BA TI Improvement of thermal contact resistance by carbon nanotubes and nanofibers SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE carbon nanotube; carbon nanofibers; thermal conductivity; thermal resistance; chemical vapor deposition ID MULTILAYERED METAL-CATALYSTS; CHEMICAL-VAPOR-DEPOSITION; CONDUCTIVITY; GROWTH; HEAT AB Interfacial thermal resistance results of various nanotube and nanofiber coatings, prepared by chemical vapor deposition (CVD) methods, are reported at relatively low clamping pressures. The five types of samples examined include multi-walled and single-walled nanotubes growth by CVD, multi-walled nanotubes grown by plasma enhanced CVD (PECVD) and carbon nanofibers of differing aspect ratio grown by PECVD. Of the samples examined, only high aspect ratio nanofibers and thermally grown multi-walled nanotubes show an improvement in thermal contact resistance. The improvement is approximately a 60% lower thermal resistance than a bare Si-Cu interface and is comparable to that attained by commercially available thermal interface materials. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Cruden, BA (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. NR 14 TC 36 Z9 36 U1 2 U2 5 PU AMER SCIENTIFIC PUBLISHERS PI VALENCIA PA 26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA SN 1533-4880 EI 1533-4899 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD NOV PY 2004 VL 4 IS 8 BP 964 EP 967 DI 10.1166/jnn.2004.152 PG 4 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 881MQ UT WOS:000225872000003 PM 15656186 ER PT J AU Kolasinski, RD Polk, JE AF Kolasinski, RD Polk, JE TI Characterization of cathode keeper wear by surface layer activation SO JOURNAL OF PROPULSION AND POWER 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 The erosion rates of the discharge cathode keeper in a 30 cm NASA Solar Electric Propulsion Technology Applications Readiness (NSTAR) configuration ion thruster were measured using a technique known as surface layer activation (SLA). This diagnostic involved producing a radioactive tracer in the keeper surface by high-energy proton bombardment. The decrease in activity of the tracer material was monitored with a gamma spectroscopy system after the surface was subjected to wear processes. Correlation with a depth calibration curve yielded the eroded depth. The primary objectives were to validate the technique by reproducing erosion data from previous wear studies and to determine the effect of different engine operating parameters on erosion rate. The erosion profile at the TH 15 (2.3-kW) setting observed during the 8200-h life demonstration test was reproduced with a measured maximum erosion rate of 0.085 mum/h. Testing at the TH 8 (1.4-kW) setting demonstrated that variations in keeper voltage had a significant effect on the erosion, with a positive bias with respect to cathode potential decreasing the wear rate significantly. Measurements were achieved after operating times of 40-90 h, with a typical uncertainty of 0.003 mum/h. C1 CALTECH, Dept Mech Engn, Div Engn & Appl Sci, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kolasinski, RD (reprint author), CALTECH, Dept Mech Engn, Div Engn & Appl Sci, Mail Code 301-46, Pasadena, CA 91125 USA. EM rdk@caltech.edu NR 19 TC 5 Z9 5 U1 2 U2 3 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 NOV-DEC PY 2004 VL 20 IS 6 BP 992 EP 999 DI 10.2514/1.6191 PG 8 WC Engineering, Aerospace SC Engineering GA 873WM UT WOS:000225312200005 ER PT J AU Karabeyoglu, A Zilliac, G Cantwell, BJ DeZilwa, S Castellucci, P AF Karabeyoglu, A Zilliac, G Cantwell, BJ DeZilwa, S Castellucci, P TI Scale-up tests of high regression rate paraffin-based hybrid rocket fuels SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT AIAA 41st Aerospace Sciences Meeting CY JAN 06-09, 2003 CL RENO, NV SP Amer Inst Aeronaut & Astronaut ID COMBUSTION; PROPELLANTS AB Recent research at Stanford University has led to the identification of a class of paraffin-based fuels that burn at surface regression rates that are three to four times that of conventional hybrid fuels. The approach involves the use of materials that form a thin, hydrodynamically unstable liquid layer on the melting surface of the fuel. Entrainment of droplets from the liquid-gas interface substantially increases the rate of fuel mass transfer, leading to much higher surface regression rates than can be achieved with conventional polymeric fuels. Thus, high regression rate is a natural attribute of the fuel material, and the use of oxidizing additives or other regression rate enhancement schemes is not required. The high regression rate hybrid removes the need for a complex multiport grain, and most applications up to large boosters can be designed with a single port configuration. The fuel contains no toxic or hazardous components and can be shipped by commercial freight as a nonhazardous commodity. At the present time, grains up to 0.19 m [19.1 cm (7.5 in.)] in diameter and 1.14 m [114.8 cm (45.2 in.)] long are fabricated in a general-purpose laboratory at Stanford University. To further demonstrate the feasibility of this approach, a series of scale-up tests with gaseous oxygen have been carried out using a new Hybrid Combustion Facility (HCF) at NASA Ames Research Center. Data from these tests are in agreement with the small-scale, low-pressure, and low mass flux laboratory tests at Stanford University and confirm the high regression rate behavior of the fuels at chamber pressures and mass fluxes representative of commercial applications. C1 Stanford Univ, Dept Aeronaut & Astronaut, Stanford, CA 94305 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Karabeyoglu, A (reprint author), Stanford Univ, Dept Aeronaut & Astronaut, Stanford, CA 94305 USA. NR 16 TC 22 Z9 23 U1 0 U2 13 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 NOV-DEC PY 2004 VL 20 IS 6 BP 1037 EP 1045 DI 10.2514/1.3340 PG 9 WC Engineering, Aerospace SC Engineering GA 873WM UT WOS:000225312200010 ER PT J AU Gostowski, R AF Gostowski, R TI Compatibility of injector materials with hydrogen peroxide propellant SO JOURNAL OF PROPULSION AND POWER LA English DT Article C1 NASA, George C Marshall Space Flight Ctr, Prop Res Ctr, Huntsville, AL 35812 USA. RP Gostowski, R (reprint author), NASA, George C Marshall Space Flight Ctr, Prop Res Ctr, Huntsville, AL 35812 USA. NR 10 TC 0 Z9 0 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 NOV-DEC PY 2004 VL 20 IS 6 BP 1126 EP 1127 DI 10.2514/1.7092 PG 2 WC Engineering, Aerospace SC Engineering GA 873WM UT WOS:000225312200020 ER PT J AU Yang, P Zhang, ZB Baum, BA Huang, HL Hu, YX AF Yang, P Zhang, ZB Baum, BA Huang, HL Hu, YX TI A new look at anomalous diffraction theory (ADT): Algorithm in cumulative projected-area distribution domain and modified ADT SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE anomalous diffraction theory; algorithm; extinction and absorption ID HIGH-FREQUENCY SCATTERING; LIGHT-SCATTERING; NONSPHERICAL PARTICLES; CIRCULAR-CYLINDERS; RADIATIVE-TRANSFER; ICE CRYSTALS; ABSORPTION; EXTINCTION; APPROXIMATION; EFFICIENCIES AB Two recent papers (Opt. Lett. 28 (2003) 179; Appl. Opt. 42 (2003) 6710) show that the conventional anomalous diffraction theory (ADT) can be reformulated by using the probability distribution function of the geometrical paths of rays inside a scattering particle. In this study we further enhance the new ADT formulation by introducing a dimensionless scaled projectile-length (lq) defined in the domain of the cumulative projected-area distribution (lq) of a particle. The quantity iq contains essentially all the information about particle shape and aspect ratio, which, however, is independent of particle dimension (e.g., large and small spheres have the same (lq). With this feature Of lq, the present ADT algorithm is computationally efficient if a number of particle sizes and wavelengths are considered, particularly when a random orientation condition is assumed. Furthermore, according to the fundamental ADT assumption regarding the internal field within a scattering particle, we modify ADT on the basis of two rigorous relationships that relate the extinction and absorption cross sections to the internal field. Two tuning factors are introduced in the modified ADT solution, which can be determined for spheres by fitting the modified ADT results to the corresponding Lorenz-Mie solutions. For nonspherical particles, the tuning factors obtained for spheres can be used as surrogates. This approach is tested for the case of circular cylinders whose optical properties can be accurately calculated from the T-matrix method. Numerical computations show that the moditied ADT solution is more accurate than its conventional ADT counterpart. (C) 2004 Elsevier Ltd. All rights reserved. C1 Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. NASA Langley Res Ctr, Hampton, VA 23681 USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI 53706 USA. RP Yang, P (reprint author), Texas A&M Univ, Dept Atmospher Sci, TAMU 3150, College Stn, TX 77843 USA. EM pyang@ariel.met.tamu.edu RI Zhang, Zhibo/D-1710-2010; Yang, Ping/B-4590-2011; Baum, Bryan/B-7670-2011; Hu, Yongxiang/K-4426-2012 OI Zhang, Zhibo/0000-0001-9491-1654; Baum, Bryan/0000-0002-7193-2767; NR 38 TC 20 Z9 21 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 NOV-DEC PY 2004 VL 89 IS 1-4 BP 421 EP 442 DI 10.1016/j.jqsrt.2004.05.038 PG 22 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 856HP UT WOS:000224036600035 ER PT J AU Fan, CC Xiao, XD Edwards, JR Hassan, HA AF Fan, CC Xiao, XD Edwards, JR Hassan, HA TI Hybrid large-eddy/Reynolds-averaged Navier-Stokes simulations of shock-separated flows SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA 41st Aerospace Sciences Meeting CY JAN 06-09, 2003 CL RENO, NV SP Amer Inst Aeronaut & Astronaut ID LARGE-EDDY SIMULATION; FREE SHEAR-LAYER AB An assessment of a hybrid large-eddy/Reynolds-averaged simulation (LES/RANS) procedure for high-speed, shock-separated flows is reported. A distance-dependent blending function is used to shift the turbulence closure from Menter's k-w shear-stress-transport model near solid surfaces to a k-Delta subgrid closure away from solid surfaces and in free-shear regions. A modified recycling/rescaling procedure is used to generate time-dependent fluctuation data that are fed into the inflow plane for some calculations, with the goal being to replace the incoming boundary layer with a hybrid LES/RANS boundary layer that maintains nearly the same levels of fluctuation energy. Simulations of Mach 3 flow over a ramped-cavity configuration highlight the effects of grid refinement and choice of hybridization strategy, while simulations of Mach 3 flow over a 20-deg compression corner illustrate the effects of the choice of model constants and the inclusion of boundary-layer recycling on the mean-flow solutions. C1 N Carolina State Univ, Dept Mech & Aerosp Engn, Raleigh, NC 27695 USA. NASA, Langley Res Ctr, Hyperson Airbreathing Prop Branch, Hampton, VA 23681 USA. RP Fan, CC (reprint author), N Carolina State Univ, Dept Mech & Aerosp Engn, Campus Box 7910, Raleigh, NC 27695 USA. NR 32 TC 19 Z9 23 U1 0 U2 4 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 NOV-DEC PY 2004 VL 41 IS 6 BP 897 EP 906 DI 10.2514/1.3735 PG 10 WC Engineering, Aerospace SC Engineering GA 881ER UT WOS:000225846700001 ER PT J AU Vayner, B Galofaro, J Ferguson, D AF Vayner, B Galofaro, J Ferguson, D TI Interactions of high-voltage solar arrays with their plasma environment: Physical processes SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID VACUUM; DISCHARGES; EMISSION; COPPER AB The results of an experimental study and theoretical analysis are presented to reveal some important physical mechanisms of electrostatic discharge inception due to charging of conductor-dielectric junctions immersed in low-density plasmas. Two samples of conventional solar arrays and four quartz-metal junctions were used to investigate the effects of arcing within a wide range of neutral gas pressures, ion currents, and electron number densities. Collected data allowed the study the correlation between external parameters (plasma density, additional capacitance, bias voltage, and metal work function) and arc characteristics (arc rate, arc current pulse width and amplitude, plasma contamination, and intensities of spectral lines). The locations of arc sites on solar array samples were determined by video camera, and it is shown that the most probable sites for arc inception are interconnect-coverglass junctions, even though some arcs were initiated in gaps between cells. The effect of surface conditioning (a decrease of the arc rate due to outgassing) was clearly demonstrated. Moreover, a considerable increase in arc rate due to the absorption of molecules from the air has been confirmed. The analysis of optical spectra (220-680 nm) reveals intense narrow atomic lines (Ag, Cu, and H) and wide molecular bands (OH, CH, SiH, and SiN) that imply a complicated mechanism of arc plasma generation. The rate of plasma contamination due to arcing was measured by employing a mass spectrometer. The arc threshold was increased to above 350 V (from 190 V) by keeping a sample in vacuum for seven days. The results obtained are important for the understanding of the arc inception mechanism, which is essential for progress toward the design of high-voltage solar arrays for space applications. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, John H Glenn Res Ctr, Photovoltaic & Space Environm Branch, Cleveland, OH 44135 USA. RP Ohio Aerosp Inst, Cleveland, OH 44142 USA. EM vayner@grc.nasa.gov NR 32 TC 10 Z9 10 U1 0 U2 4 PU AMER INST AERONAUTICS ASTRONAUTICS PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 EI 1533-6794 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD NOV-DEC PY 2004 VL 41 IS 6 BP 1031 EP 1041 DI 10.2514/1.4271 PG 11 WC Engineering, Aerospace SC Engineering GA 881ER UT WOS:000225846700016 ER PT J AU Vayner, B Galofaro, J Ferguson, D AF Vayner, B Galofaro, J Ferguson, D TI Interactions of high-voltage solar arrays with their plasma environment: Ground tests SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB Five different types of solar arrays have been tested in a large vacuum chamber. Are inception voltages, arc rates, and current collections were measured for samples with different coverglass materials and thickness, interconnect designs, and cell sizes. It is shown that the array with wrapthrough interconnects has the highest arc threshold and the lowest current collection. Coverglass designs with overhang result in a decrease of current collection and increase of arc threshold. Doubling coverglass thickness does not improve measured array parameters. Both arc inception voltage and current collection increase significantly with increasing the sample temperature to 80degreesC. The sample with exposed interconnects demonstrated a significant (30 times) drop in arc rate after it underwent five thermal cycles in a clean chamber to outgas its surfaces. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, John H Glenn Res Ctr, Photovoltaic & Space Environm Branch, Cleveland, OH 44135 USA. RP Vayner, B (reprint author), Ohio Aerosp Inst, Cleveland, OH 44142 USA. EM vayner@grc.nasa.gov NR 14 TC 12 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 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD NOV-DEC PY 2004 VL 41 IS 6 BP 1042 EP 1050 DI 10.2514/1.4272 PG 9 WC Engineering, Aerospace SC Engineering GA 881ER UT WOS:000225846700017 ER PT J AU Starin, SR O'Donnell, JR Ward, DK Wollack, EJ Bay, PM Fink, DR AF Starin, SR O'Donnell, JR Ward, DK Wollack, EJ Bay, PM Fink, DR TI Anomalous force on the Wilkinson Microwave Anisotropy Probe SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB The Wilkinson Microwave Anisotropy Probe orbits the outer Earth-sun libration point, about 1.5 million kilometers outside Earth's orbit, mapping cosmic microwave background radiation. To achieve its orbit on a small fuel budget, the spacecraft needed to perform a lunar gravity assist maneuver. Timing the lunar swing-by required the spacecraft to travel in three high-eccentricity phasing loops with critical maneuvers at a minimum of two, but nominally all three, of the perigee passes. On the approach to the first perigee maneuver, spacecraft telemetry showed a considerable change in system angular momentum that threatened to cause the onboard failure detection and correction software to abort the critical maneuver. Fortunately, the system momentum did not reach the preset failure detection limit; however, the mission operations team did develop a contingency strategy should a stronger anomaly occur before or during subsequent perigee maneuvers. Simultaneously, the team developed and tested various hypotheses for the cause of the anomalous force. The final hypothesis was that water was outgassing from the thermal blanketing and freezing to the cold side of the solar shield. As radiation from Earth warmed the cold side of the spacecraft, the uneven sublimation of ice created a torque on the spacecraft. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Jackson & Tull, Lanham, MD 20706 USA. Comp Sci Corp, Lanham, MD 20706 USA. RP Starin, SR (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Wollack, Edward/D-4467-2012 OI Wollack, Edward/0000-0002-7567-4451 NR 6 TC 1 Z9 1 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 NOV-DEC PY 2004 VL 41 IS 6 BP 1056 EP 1062 DI 10.2514/1.14250 PG 7 WC Engineering, Aerospace SC Engineering GA 881ER UT WOS:000225846700019 ER PT J AU Li, XF Finkbeiner, J Raman, G Daniels, C Steinetz, BM AF Li, XF Finkbeiner, J Raman, G Daniels, C Steinetz, BM TI Optimized shapes of oscillating resonators for generating high-amplitude pressure waves SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID ACOUSTICAL RESONATOR; CLOSED CAVITIES; STANDING WAVES AB Several studies have proved that the geometry of an oscillating acoustic resonator strongly influences its resonance frequencies and the nonlinear standing pressure waveform generated within the cavity. The research presented herein uses a quasi-one-dimensional numerical model to solve the acoustic field and is validated by comparing with experimental results. A quasi-Newton type numerical scheme is used to optimize the axisymmetric cavity contour by maximizing the pressure compression ratio, defined as the ratio of maximum to minimum gas pressure at one end of the oscillating resonator. Cone, horn-cone, and cosine resonator contours are each optimized for a fixed amplitude of the periodic external force oscillating the cavity. Different optimized shapes are found when starting with different initial guesses, indicating multiple local extrema. The maximum pressure compression ratio value of 48 is found in an optimized horn-cone shape. This represents a 241 % increase in the compression ratio over any previously published results. (C) 2004 Acoustical Society of America. C1 IIT, Dept Appl Math, Chicago, IL 60616 USA. IIT, Dept Mech Mat & Aerosp Engn, Chicago, IL 60616 USA. Univ Akron, Akron, OH 44325 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Li, XF (reprint author), IIT, Dept Appl Math, Chicago, IL 60616 USA. EM lix@iit.edu NR 12 TC 9 Z9 13 U1 0 U2 1 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 NOV PY 2004 VL 116 IS 5 BP 2814 EP 2821 DI 10.1121/1.1810139 PG 8 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 874DQ UT WOS:000225331500013 ER PT J AU Heinrichs, WL Srivastava, S Montgomery, K Dev, P AF Heinrichs, WL Srivastava, S Montgomery, K Dev, P TI The fundamental manipulations of surgery: A structural vocabulary for designing surgical curricula and simulators SO JOURNAL OF THE AMERICAN ASSOCIATION OF GYNECOLOGIC LAPAROSCOPISTS LA English DT Article ID OPERATING-ROOM; LAPAROSCOPIC SIMULATOR; PERFORMANCE; RESIDENTS; SKILLS AB A structured vocabulary is proposed for supporting the design and development of advanced surgical simulators. Nine fundamental surgical instrument-tissue actions or manipulations are defined and common synonyms provided. The vocabulary focuses on "target skills" that are familiar to surgeons, in comparison with "enabling skills" from the lexicon of instructional designers and psychometricians. The adoption of this vocabulary can facilitate communication among surgeons and bioengineers developing "high-fidelity" surgical simulators. C1 Stanford Univ, Sch Med, SUMMIT, Stanford, CA 94305 USA. Stanford Univ, Sch Med, Dept Obstet & Gynecol, Stanford, CA 94305 USA. Stanford Univ, Sch Med, Dept Surg, Stanford, CA 94305 USA. Stanford Univ, Sch Med, Stanford NASA Natl Biocomputat Ctr, Stanford, CA 94305 USA. RP Heinrichs, WL (reprint author), Stanford Univ, Sch Med, SUMMIT, 351 Campus Dr,MSOB Room 230, Stanford, CA 94305 USA. NR 17 TC 10 Z9 10 U1 0 U2 0 PU JOURNAL AMER ASSOC GYNECOLOGIC LAPAROSCOPISTS PI SANTA FE SPRINGS PA 13021 EAST FLORENCE AVE, SANTA FE SPRINGS, CA 90670-4505 USA SN 1074-3804 J9 J AM ASSOC GYN LAP JI J. Am. Assoc. Gynecol. Laparoscopists PD NOV PY 2004 VL 11 IS 4 BP 450 EP 456 DI 10.1016/S1074-3804(05)60073-4 PG 7 WC Obstetrics & Gynecology SC Obstetrics & Gynecology GA 874BS UT WOS:000225326500004 PM 15701184 ER PT J AU Turner, DD Tobin, DC Clough, SA Brown, PD Ellingson, RG Mlawer, EJ Knuteson, RO Revercomb, HE Shippert, TR Smith, WL Shephard, MW AF Turner, DD Tobin, DC Clough, SA Brown, PD Ellingson, RG Mlawer, EJ Knuteson, RO Revercomb, HE Shippert, TR Smith, WL Shephard, MW TI The QME AERI LBLRTM: A closure experiment for downwelling high spectral resolution infrared radiance SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID MOLECULAR SPECTROSCOPIC DATABASE; INTENSIVE OBSERVATION PERIODS; WATER-VAPOR MEASUREMENTS; RAMAN LIDAR; ATMOSPHERIC RADIATION; CONTINUUM ABSORPTION; MICROWAVE RADIOMETERS; CLIMATE MODELS; COOLING RATES; LINE AB Research funded by the U. S. Department of Energy's Atmospheric Radiation Measurement (ARM) program has led to significant improvements in longwave radiative transfer modeling over the last decade. These improvements, which have generally come in small incremental changes, were made primarily in the water vapor self- and foreign-broadened continuum and the water vapor absorption line parameters. These changes, when taken as a whole, result in up to a 6 W m(-2) improvement in the modeled clear-sky downwelling longwave radiative flux at the surface and significantly better agreement with spectral observations. This paper provides an overview of the history of ARM with regard to clear-sky longwave radiative transfer, and analyzes remaining related uncertainties in the ARM state-of-the-art Line-by-Line Radiative Transfer Model (LBLRTM). A quality measurement experiment (QME) for the downwelling infrared radiance at the ARM Southern Great Plains site has been ongoing since 1994. This experiment has three objectives: 1) to validate and improve the absorption models and spectral line parameters used in line-by-line radiative transfer models, 2) to assess the ability to define the atmospheric state, and 3) to assess the quality of the radiance observations that serve as ground truth for the model. Analysis of data from 1994 to 1997 made significant contributions to optimizing the QME, but is limited by small but significant uncertainties and deficiencies in the atmospheric state and radiance observations. This paper concentrates on the analysis of QME data from 1998 to 2001, wherein the data have been carefully selected to address the uncertainties in the 1994-97 dataset. Analysis of this newer dataset suggests that the representation of self- broadened water vapor continuum absorption is 3%-8% too strong in the 750-1000 cm(-1) region. The dataset also provides information on the accuracy of the self- and foreign-broadened continuum absorption in the 1100-1300 cm(-1) region. After accounting for these changes, remaining differences in modeled and observed downwelling clear-sky fluxes are less than 1.5 W m(-2) over a wide range of atmospheric states. C1 Pacific NW Natl Lab, Climate Phys Grp, Richland, WA 99352 USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI USA. Florida State Univ, Tallahassee, FL 32306 USA. Atmospher & Environm Res Inc, Lexington, MA USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Turner, DD (reprint author), Pacific NW Natl Lab, Climate Phys Grp, MS K9-24,POB 999, Richland, WA 99352 USA. EM dave.turner@pnl.gov NR 67 TC 59 Z9 59 U1 0 U2 4 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 NOV PY 2004 VL 61 IS 22 BP 2657 EP 2675 DI 10.1175/JAS3300.1 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 874YC UT WOS:000225385600001 ER PT J AU Fischer, DG Visser, TD AF Fischer, DG Visser, TD TI Spatial correlation properties of focused partially coherent light SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID SINGULARITIES; STATE AB We investigate the spatial coherence properties in the focal region of a converging, spatially partially coherent wave field. In particular, we find that, depending on the effective coherence length of the field in the aperture, the longitudinal and transverse coherence lengths in the focal region can be either larger or smaller than the corresponding width of the intensity distribution. Also, the correlation function is shown to exhibit phase singularities. (C) 2004 Optical Society of America. C1 NASA, Glenn Res Ctr, Micrograv Sci Div, Cleveland, OH 44135 USA. RP Visser, TD (reprint author), NASA, Glenn Res Ctr, Micrograv Sci Div, 21000 Brookpk Rd,MS 110-3, Cleveland, OH 44135 USA. EM tvisser@nat.vu.nl NR 10 TC 53 Z9 53 U1 0 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1084-7529 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD NOV PY 2004 VL 21 IS 11 BP 2097 EP 2102 DI 10.1364/JOSAA.21.002097 PG 6 WC Optics SC Optics GA 865RX UT WOS:000224721500006 PM 15535367 ER PT J AU Bose, D Rauf, S Hash, DB Govindan, TR Meyyappan, M AF Bose, D Rauf, S Hash, DB Govindan, TR Meyyappan, M TI Monte Carlo sensitivity analysis of CF2 and CF radical densities in a c-C4F8 plasma SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Article ID ELECTRON-IMPACT DISSOCIATION; CROSS-SECTIONS; CHF3; DISCHARGES; CHEMISTRY; C2F6; C4F8; ION; OCTAFLUOROCYCLOBUTANE; IONIZATION AB A Monte Carlo sensitivity analysis is used to build a plasma chemistry model for octacyclofluorobutane (c-C4F8) which is commonly used in dielectric etch. Experimental data are used both quantitatively and qualitatively to analyze the gas phase and gas surface reactions for neutral radical chemistry. The sensitivity data of the resulting model identifies a few critical gas phase and surface aided reactions that account for most of the uncertainty in the CF2 and CF radical densities. Electron impact dissociation of small radicals (CF2 and CF) and their surface recombination reactions are found to be the rate-limiting steps in the neutral radical chemistry. The relative rates for these electron impact dissociation and surface recombination reactions are also suggested. The resulting mechanism is able to explain the measurements of CF2 and CF densities available in the literature and also their hollow spatial density profiles. (C) 2004 American Vacuum Society. C1 NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA. Motorola Inc, Semicond Prod Sector, Adv Prod Res & Dev Lab, Austin, TX 78721 USA. RP Bose, D (reprint author), NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA. NR 36 TC 16 Z9 16 U1 1 U2 5 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A PD NOV-DEC PY 2004 VL 22 IS 6 BP 2290 EP 2298 DI 10.1116/1.1795826 PG 9 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 876OF UT WOS:000225505900013 ER PT J AU Kelkar, AG Joshi, SM AF Kelkar, AG Joshi, SM TI Control of elastic systems via passivity-based methods SO JOURNAL OF VIBRATION AND CONTROL LA English DT Article DE vibration control; elastic systems; passivity; robust control; dissipative systems ID DISSIPATIVE DYNAMICAL-SYSTEMS; ROBUST-CONTROL; BENCHMARK; ACTUATORS; STABILITY; SENSORS; DESIGN AB In this paper we present a controller synthesis approach for elastic systems based on the mathematical concept of passivity. For nonlinear and linear elastic systems that are inherently passive, robust control laws are presented that guarantee stability. Examples of such systems include flexible structures with collocated and compatible actuators and sensors, and multibody space-based robotic manipulators. For linear elastic systems that are not inherently passive, methods are presented for rendering them passive by compensation. The "passified" systems can then be robustly controlled by a class of passive linear controllers that guarantee stability despite uncertainties and inaccuracies in the mathematical models. The controller synthesis approach is demonstrated by application to five different types of elastic systems. C1 Iowa State Univ Sci & Technol, Dept Mech Engn, Ames, IA 50011 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Kelkar, AG (reprint author), Iowa State Univ Sci & Technol, Dept Mech Engn, Ames, IA 50011 USA. NR 42 TC 5 Z9 5 U1 0 U2 5 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1077-5463 J9 J VIB CONTROL JI J. Vib. Control PD NOV PY 2004 VL 10 IS 11 BP 1699 EP 1735 DI 10.1177/1077546304042066 PG 37 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 873KJ UT WOS:000225278500007 ER PT J AU Furukawa, Y Smith, AC Kostka, JE Watkins, J Alexander, CR AF Furukawa, Y Smith, AC Kostka, JE Watkins, J Alexander, CR TI Quantification of macrobenthic effects on diagenesis using a multicomponent inverse model in salt marsh sediments SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID SULFATE REDUCTION; MARINE-SEDIMENTS; AQUATIC SEDIMENTS; ORGANIC-MATTER; CONTINENTAL-MARGIN; IRON REDUCTION; SAPELO ISLAND; FIDDLER-CRABS; OXIDATION; SULFUR AB Using a multicomponent inverse model, we quantified the rates of organic matter (OM) remineralization and the relative importance of major terminal electron acceptors [Fe(III)-(oxy)hydroxides and SO42-] in salt marsh sediments with varying degrees of bioturbation and vegetation at Skidaway Island, Georgia. The model determined the rates of OM diagenesis by seeking simultaneous agreement between measured and model-calculated depth-concentration profiles of multiple major redox species while using the biological transport parameters determined from direct field observations. The OM degradation rates are found to be greater and penetrate deeper in sediments with vegetation or bioturbation than in sediments with limited macrobenthic components, in which organic matter degradation is restricted to the immediate vicinity of water-sediment interface. The results also confirmed previous observations that Fe(III)-(oxy)hydroxides are much more important than sulfate as terminal electron acceptors in the heavily bioturbated station and provided the numerical values to the depth-dependent relative importance. Solid-phase Fe is recycled as a terminal electron acceptor greater than or equal to30 times in the bioturbated station, because biological mixing repeatedly moves reduced Fe(II) back into the aerobic environment, where it is reoxidized to form Fe(III)-(oxy)hydroxides and is reused as a terminal electron acceptor. Vegetation appears to have little influence on net solute transport, but it stimulates microbial activities and significantly enhances the remineralization of OM at depths. C1 USN, Res Lab, Seafloor Sci Branch, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. Florida State Univ, Dept Oceanog, Tallahassee, FL 32306 USA. Skidaway Inst Oceanog, Savannah, GA 31411 USA. RP Furukawa, Y (reprint author), USN, Res Lab, Seafloor Sci Branch, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. EM yfurukawa@nrlssc.navy.mil RI Furukawa, Yoko/B-3099-2013 NR 51 TC 13 Z9 14 U1 0 U2 8 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 EI 1939-5590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD NOV PY 2004 VL 49 IS 6 BP 2058 EP 2072 PG 15 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 871MF UT WOS:000225137100015 ER PT J AU Ciesla, FJ Hood, LL Weidenschilling, SJ AF Ciesla, FJ Hood, LL Weidenschilling, SJ TI Evaluating planetesimal bow shocks as sites for chondrule formation SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID SOLAR NEBULA; COOLING RATES; HEATING MODEL; GAP FORMATION; PARTICLES; SIMULATIONS; RESONANCES; EVOLUTION; MIGRATION; PLANETS AB We investigate the possible formation of chondrules by planetesimal bow shocks. The formation of such shocks is modeled using a piecewise parabolic method (PPM) code under a variety of conditions. The results of this modeling are used as a guide to study chondrule formation in a one-dimensional, finite shock wave. This model considers a mixture of chondrule-sized particles and micron-sized dust and models the kinetic vaporization of the solids. We found that only planetesimals with a radius of similar to 1000 km and moving at least similar to 8 km/s with respect to the nebular gas can generate shocks that would allow chondrule-sized particles to have peak temperatures and cooling rates that are generally consistent with what has been inferred for chondrules. Planetesimals with smaller radii tend to produce lower peak temperatures and cooling rates that are too high. However, the peak temperatures of chondrules are only matched for low values of chondrule wavelength-averaged emissivity. Very slow cooling ( < similar to 100s of K/hr) can only be achieved if the nebular opacity is low, which may result after a significant amount of material has been accreted into objects that are chondrule-sized or larger, or if chondrules formed in regions of the nebula with small dust concentrations. Large shock waves of approximately the same scale as those formed by gravitational instabilities or tidal interactions between the nebula and a young Jupiter do not require this to match the inferred thermal histories of chondrules. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Planetary Sci Inst, Tucson, AZ 85719 USA. RP Ciesla, FJ (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. EM ciesla@cosmic.arc.nasa.gov NR 30 TC 30 Z9 30 U1 1 U2 6 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD NOV PY 2004 VL 39 IS 11 BP 1809 EP 1821 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 886FC UT WOS:000226211300004 ER PT J AU Kletetschka, G Connerney, JEP Ness, NF Acuna, MH AF Kletetschka, G Connerney, JEP Ness, NF Acuna, MH TI Pressure effects on martian crustal magnetization near large impact basins SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID REMANENT MAGNETIZATION; MARS; ANOMALIES; HEMATITE; ROCKS; MAGNETISM; DEMAGNETIZATION; SHOCK; TOPOGRAPHY; SIGNATURE AB Martian crust endured several large meteoroid impacts subsequent to the demise of an early global magnetic field. Shock pressures associated with these impacts demagnetized parts of the crust, to an extent determined by shock resistance of magnetic materials in the crust. Impacts that form large basins generate pressures in excess of 1 GPa within a few crater radii of their impact sites. Crustal materials near the surface experience significantly reduced impact pressure, which varies with depth and distance from the impact point. We present new demagnetization experiments on magnetite (Fe3O4), hematite (alpha-Fe2O3), and titanohematite (Fe2-xTixO3 where x < 0.2). Our measurements show that pressures of similar to 1 GPa are sufficient to partially demagnetize all of these minerals. The efficiency of demagnetization by impact pressure is proportional to the logarithm of the minerals' magnetic coercivity. The impact pressure magnetic response from exsolved titanohematite samples is consistent with the magnetization decay near Prometheus impact basin and may point to an oxidized igneous rock in Terra Sirenum region at the time of acquisition of magnetic remanence. The remaining magnetic anomalies near large impact basins suggest moderate crustal coercivity. These anomalies point to titanomagnetite as a magnetic carrier and more reduced condition during crustal formation. 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. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. 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; connerney, john/I-5127-2013 OI Kletetschka, Gunther/0000-0002-0645-9037; NR 46 TC 32 Z9 33 U1 0 U2 6 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD NOV PY 2004 VL 39 IS 11 BP 1839 EP 1848 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 886FC UT WOS:000226211300006 ER PT J AU Bhushan, B Kasai, T Nguyen, CV Meyyappan, M AF Bhushan, B Kasai, T Nguyen, CV Meyyappan, M TI Multiwalled carbon nanotube AFM probes for surface characterization of micro/nanostructures SO MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS LA English DT Article ID SCANNING PROBE; MICROSCOPY; FABRICATION; RESOLUTION; ROUGHNESS; DEVICES; TIP AB A multiwalled carbon nanotube (MWNT) probe was used as a scanning probe in an atomic force microscope (AFM) to obtain surface height maps of micro/nano structures. The surface height maps acquired by the MWNT probe are compared with those by a conventional silicon probe on the four samples: silicon ruler, polymer microchannels, silicon nanomembrane and nanocomposite metal particle (MP) tapes. The results of the silicon ruler, microchannels and membrane samples show that the surface height maps by the MWNT probe have a better resolution than those by a conventional silicon tip due to the sharper tip with the larger aspect ratio of the MWNT. A MWNT probe is especially useful to observe surface height maps of the structures that have larger aspect ratio. C1 Ohio State Univ, Nanotribol Lab Informat Storage & MEMS NEMS, Columbus, OH 43202 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Bhushan, B (reprint author), Ohio State Univ, Nanotribol Lab Informat Storage & MEMS NEMS, 650 Ackerman Rd,Suite 255, Columbus, OH 43202 USA. EM Bhushan.2@osu.edu RI Bhushan, Bharat/A-9684-2013 OI Bhushan, Bharat/0000-0001-7161-6601 NR 21 TC 10 Z9 10 U1 3 U2 7 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0946-7076 J9 MICROSYST TECHNOL JI Microsyst. Technol. PD NOV PY 2004 VL 10 IS 8-9 BP 633 EP 639 DI 10.1007/s00542-004-0489-x PG 7 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Science & Technology - Other Topics; Materials Science; Physics GA 868CA UT WOS:000224888900009 ER PT J AU Felix, K Wise, K Manna, S Yamauchi, K Wilson, BL Thomas, RL Kulkarni, A Pellis, NR Ramesh, GT AF Felix, K Wise, K Manna, S Yamauchi, K Wilson, BL Thomas, RL Kulkarni, A Pellis, NR Ramesh, GT TI Altered cytokine expression in tissues of mice subjected to simulated microgravity SO MOLECULAR AND CELLULAR BIOCHEMISTRY LA English DT Article DE antiorthostatic suspension (AOS); cytokine; microgravity; mice ID LISTERIA-MONOCYTOGENES INFECTION; SPACE-FLIGHT; ANTIORTHOSTATIC SUSPENSION; IMMUNE-SYSTEM; CELLULAR-IMMUNITY; SPACEFLIGHT; INTERFERON; RESPONSES; MODEL; MOUSE AB Space flight is known to induce microgravity-associated immune dysfunction in humans, non-human primates and rodents. To understand the mechanism underlying these defects, several studies in rodents have been conducted in a ground-based antiorthostatic suspension (AOS) model that would mimic the effects of microgravity. In all these in vivo studies that showed the effects on cytokine profiles actually investigated the ex vivo production from culturing the cells isolated from whole organism that was exposed to space flight and/or microgravity. So, the purpose of the study was to examine the in vivo expression of cytokines in mice in immunologically important tissue environments of mice that were subjected to AOS. Cytokines such as Interleukin-1beta (IL-1beta), IL-2, IL-3, IL-6, Interferon-gamma (IFN-gamma) and Tumor Necrosis Factor-alpha (TNF-alpha) were measured by Enzyme Linked Immunosorbent Assay (ELISA) in the homogenates of spleen tissue, lymph nodes and also in serum of AOS mice and compared with that of control mice. AOS induced no change in the IL-3 levels, but IL-1beta was increased significantly whereas IL-2 levels decreased in spleen, lymph nodes and serum. IL-6 levels did not differ in spleen but were significantly increased in lymph nodes and serum of AOS mice. IFN-gamma levels in spleen did not change but showed nonsignificant reduction in lymph nodes and significant reduction in serum in response to AOS. TNF-alpha levels in spleen and serum were unchanged and increased in lymph nodes. This in vivo cytokine study confirms the earlier findings that microgravity-simulated conditions induce tissue-specific immune response. C1 Texas So Univ, Mol Neurotoxicol Lab, Dept Biol, Houston, TX 77004 USA. Univ Texas, Dept Surg, Houston, TX USA. Ctr DNA Fingerprinting & Diagnost, Immunol Lab, Hyderabad, Andhra Pradesh, India. NASA JSC, Cellular Biotechnol Program, Houston, TX USA. Texas So Univ, Dept Chem, Houston, TX 77004 USA. RP Ramesh, GT (reprint author), Texas So Univ, Mol Neurotoxicol Lab, Dept Biol, 1300 Cleburne St, Houston, TX 77004 USA. EM Ramesh_gt@tsu.edu NR 45 TC 19 Z9 22 U1 1 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0300-8177 J9 MOL CELL BIOCHEM JI Mol. Cell. Biochem. PD NOV PY 2004 VL 266 IS 1-2 BP 79 EP 85 DI 10.1023/B:MCBI.0000049136.55611.dd PG 7 WC Cell Biology SC Cell Biology GA 873RY UT WOS:000225299800009 PM 15646029 ER PT J AU Shapiro, BE Heisler, M Reddy, GV Jonsson, H Gor, V Meyerowitz, EM Mjolsness, E AF Shapiro, BE Heisler, M Reddy, GV Jonsson, H Gor, V Meyerowitz, EM Mjolsness, E TI Developmental modeling of the Arabidopsis shoot apical meristem SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract CT Annual Meeting of the American-Society-for-Cell-Biology CY DEC 04-08, 2004 CL Washington, DC SP Amer Soc Cell Biol C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. CALTECH, Div Biol, Pasadena, CA 91125 USA. Lund Univ, Complex Syst Div, S-22100 Lund, Sweden. Univ Calif Irvine, Dept Informat & Comp Sci, Irvine, CA 92717 USA. RI Meyerowitz, Elliot/A-7118-2009; OI heisler, marcus/0000-0001-5644-8398 NR 0 TC 0 Z9 0 U1 1 U2 2 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD NOV PY 2004 VL 15 SU S MA 1204 BP 217A EP 217A PG 1 WC Cell Biology SC Cell Biology GA 864QU UT WOS:000224648801549 ER PT J AU Ohi, S Roach, AN Kindred, RP Kim, BC Gonda, SR AF Ohi, S Roach, AN Kindred, RP Kim, BC Gonda, SR TI Degradation of gliosarcoma spheroids effected by co-cultured hematopoietic stem cells SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract CT Annual Meeting of the American-Society-for-Cell-Biology CY DEC 04-08, 2004 CL Washington, DC SP Amer Soc Cell Biol C1 Howard Univ & Hosp, BMB, Ctr Sickle Cell Dis, Washington, DC USA. Howard Univ, Ctr Sickle Cell Dis, Washington, DC 20059 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD NOV PY 2004 VL 15 SU S MA 1695 BP 306A EP 306A PG 1 WC Cell Biology SC Cell Biology GA 864QU UT WOS:000224648802419 ER PT J AU Sognier, MA Marquette, ML Byerly, DL AF Sognier, MA Marquette, ML Byerly, DL TI Three-dimensional myoblast aggregates -- Effects of modeled microgravity SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract CT Annual Meeting of the American-Society-for-Cell-Biology CY DEC 04-08, 2004 CL Washington, DC SP Amer Soc Cell Biol C1 Univ Space Res Assoc, Div Space & Life Sci, Houston, TX USA. Univ Texas, Med Branch, Grad Sch Biomed Sci, Galveston, TX 77550 USA. NASA, Lyndon B Johnson Space Ctr, Biol Syst Off, Houston, TX 77058 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD NOV PY 2004 VL 15 SU S BP 349A EP 350A PG 2 WC Cell Biology SC Cell Biology GA 864QU UT WOS:000224648803006 ER PT J AU Chen, H Han, J Li, J Meyyappan, M AF Chen, H Han, J Li, J Meyyappan, M TI Microelectronic DNA assay for detection of specific mutations in BRCA1 and BRCA2 among Ashkenazi Jews SO MOLECULAR BIOLOGY OF THE CELL LA English DT Meeting Abstract CT Annual Meeting of the American-Society-for-Cell-Biology CY DEC 04-08, 2004 CL Washington, DC SP Amer Soc Cell Biol C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER SOC CELL BIOLOGY PI BETHESDA PA 8120 WOODMONT AVE, STE 750, BETHESDA, MD 20814-2755 USA SN 1059-1524 J9 MOL BIOL CELL JI Mol. Biol. Cell PD NOV PY 2004 VL 15 SU S MA 2600 BP 469A EP 469A PG 1 WC Cell Biology SC Cell Biology GA 864QU UT WOS:000224648803669 ER PT J AU Hansen, FK Banday, AJ Gorski, KM AF Hansen, FK Banday, AJ Gorski, KM TI Testing the cosmological principle of isotropy: local power-spectrum estimates of the WMAP data SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE methods : data analysis; methods : statistical; techniques : image processing; cosmological parameters; cosmology : observations ID MICROWAVE-ANISOTROPY-PROBE; NON-GAUSSIANITY; CROSS-CORRELATION; GABOR TRANSFORMS; FOREGROUNDS; TEMPERATURE; ASYMMETRIES; MAPS; CMB AB We apply the Gabor transform methodology proposed by Hansen et al. to the WMAP data in order to test the statistical properties of the cosmic microwave background (CMB) fluctuation field and specifically to evaluate the fundamental assumption of cosmological isotropy. In particular, we apply the transform with several apodization scales, thus allowing the determination of the positional dependence of the angular power spectrum with either high spatial localization or high angular resolution (i.e. narrow bins in multipole space). Practically, this implies that we estimate the angular power spectrum locally in discs of various sizes positioned in different directions: small discs allow the greatest sensitivity to positional dependence, whereas larger discs allow greater sensitivity to variations over different angular scales. In addition, we determine whether the spatial position of a few outliers in the angular power spectrum could suggest the presence of residual foregrounds or systematic effects. For multipoles close to the first peak, the most deviant local estimates from the best-fitting WMAP model are associated with a few particular areas close to the Galactic plane. Such deviations also include the 'dent' in the spectrum just shortward of the first peak which was remarked upon by the WMAP team. Estimating the angular power spectrum excluding these areas gives a slightly higher first Doppler peak amplitude. Finally, we probe the isotropy of the largest angular scales by estimating the power spectrum on hemispheres and reconfirm strong indications of a north-south asymmetry previously reported by other authors. Indeed, there is a remarkable lack of power in a region associated with the North ecliptic Pole. With the greater fidelity in l-space allowed by this larger sky coverage, we find tentative evidence for residual foregrounds in the range l=2-4, which could be associated with the low measured quadrupole amplitudes and other anomalies on these angular scales (e.g. planarity and alignment). However, over the range l=5-40 the observed asymmetry is much harder to explain in terms of residual foregrounds and known systematic effects. By reorienting the coordinate axes, we partition the sky into different hemispheres and search for the reference frame which maximizes the asymmetric distribution of power. The North Pole for this coordinate frame is found to intersect the sphere at (80degrees,57degrees) in Galactic colatitude and longitude over almost the entire multipole range l=5-40. Furthermore, the strong negative outlier at l=21 and the strong positive outlier at l=39, as determined from the global power spectrum by the WMAP team, are found to be associated with the Northern and Southern hemispheres, respectively (in this frame of maximum asymmetry). Thus, these two outliers follow the general tendency of the multipoles l=5-40 to be of systematically lower amplitude in the north and higher in the south. Such asymmetric distributions of power on the sky provide a serious test for the cosmological principle of isotropy. C1 Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy. Max Planck Inst Astrophys, D-85741 Garching, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Warsaw Observ, PL-00478 Warsaw, Poland. RP Hansen, FK (reprint author), Univ Roma Tor Vergata, Dipartimento Fis, Via Ric Sci 1, I-00133 Rome, Italy. EM frodekh@roma2.infn.it; banday@MPA-Garching.MPG.DE; Krzysztof.M.Gorski@jpl.nasa.gov NR 30 TC 211 Z9 210 U1 2 U2 12 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 NOV 1 PY 2004 VL 354 IS 3 BP 641 EP 665 DI 10.1111/j.1365-2966.2004.08229.x PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 864KX UT WOS:000224633500003 ER PT J AU Hansen, FK Balbi, A Banday, AJ Gorski, KMG AF Hansen, FK Balbi, A Banday, AJ Gorski, KMG TI Cosmological parameters and the WMAP data revisited SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE methods : data analysis; methods : statistical; techniques : image processing; cosmological parameters; cosmology : observations ID MICROWAVE-ANISOTROPY-PROBE; POWER SPECTRUM ESTIMATION; CROSS-CORRELATION; GABOR TRANSFORMS; NON-GAUSSIANITY; DEUTERIUM; ABUNDANCE; FOREGROUNDS; TEMPERATURE; ASYMMETRIES AB Several recent papers have made claims about the detection of an asymmetric distribution of large-scale power in the cosmic microwave background (CMB) anisotropy as measured by the WMAP satellite. In this paper, we investigate how the estimates of particular cosmological parameters vary when inferred from power spectra computed separately on the Northern and Southern hemispheres in three frames of reference: the galactic, the ecliptic and the specific frame of reference that maximizes the asymmetry between the power spectra from the corresponding hemispheres. The study is intended to quantify the consistency of the observed spectral variations in the context of the inflationary scenario inspired models with which the data are commonly compared. We focus on the three specific parameters to which the analysis is most sensitive (spectral index n, amplitude of fluctuations A and optical depth) and find interesting variations in their estimates as determined from different hemispheres. Only multipoles in the ranges l = 2- 60, 200- 240 and 520- 560 (the latter two around the first two peaks) are included in the analysis. Polarization information could not be used since the appropriate sky maps are not publicly available. Furthermore, we fix Omega(Lambda) = 0.74, Omega(cdm) h(2) = 0.11 and Omega(total) = 1 atthese best-fitting values obtained by the WMAP team, and use a Gaussian prior centred at Omega(b)h(2) = 0.022 with sigma = 0.001 for the baryon fraction. No significant changes to the conclusions were found when these parameters were varied. When using a Gaussian prior on the spectral index n centred at n = 1 with a flat prior on the optical depth, the preferred value for the optical depth (derived in the reference frame of maximum asymmetry) in the Northern hemisphere is tau = 0 with upper limit tau < 0.08, whereas in the Southern hemisphere we find = 0.24(-0.07)(+0.06) (68 per cent confidence level). The latter result is inconsistent with = 0 at the 2sigma level. The estimated optical depth of tau = 0.17 on the (nearly) full sky found by the WMAP collaboration, and confirmed independently here, could thus in large part originate in structure associated with the Southern hemisphere. Furthermore, putting a prior on,we find values of the spectral index that are inconsistent between the two hemispheres. The exact values depend on the prior on. Our conclusions remain unaltered even when, on the basis of putative residual foreground contamination, the multipole range l = 2- 7 is excluded from the analysis. While our results should not be considered more than suggestive, the significance of the parameter differences in the two hemispheres being typically of order 2sigma ,if they are confirmed with the higher-sensitivity WMAP 2-yr data, then it may be necessary to question the assumption of cosmological isotropy and the conceptual framework within which studies of CMB anisotropy are made. C1 Univ Roma Tor Vergata, Dipartimento Fis, I-00133 Rome, Italy. Ist Nazl Fis Nucl, Sez Roma 2, I-00133 Rome, Italy. Max Planck Inst Astrophys, D-85741 Garching, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Warsaw Observ, PL-00478 Warsaw, Poland. RP Hansen, FK (reprint author), Univ Roma Tor Vergata, Dipartimento Fis, Via Ric Sci 1, I-00133 Rome, Italy. EM frodekh@roma2.infn.it; Amedeo.Balbi@roma2.infn.it; banday@mpa-garching.mpg.de; krzysztof.m.gorski@jpl.nasa.gov NR 35 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 NOV 1 PY 2004 VL 354 IS 3 BP 905 EP 912 DI 10.1111/j.1365-2966.2004.08243.x PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 864KX UT WOS:000224633500028 ER PT J AU Yang, YL Gupta, MC Dudley, KL Lawrence, RW AF Yang, YL Gupta, MC Dudley, KL Lawrence, RW TI The fabrication and electrical properties of carbon nanofibre-polystyrene composites SO NANOTECHNOLOGY LA English DT Article ID FLOATING CATALYST METHOD; DIELECTRIC BEHAVIOR; MECHANICAL-PROPERTIES; NANOTUBE-POLYSTYRENE; FIBERS; NANOCOMPOSITES; POLYCARBONATE AB Carbon nanofibre-polystyrene (PS) composites were fabricated by ultrasonic dispersion in a solution followed by spraying to cast films. These films were then hot-pressed to form thicker structures. Direct current conductivity measurement results show that the conductivity of the composite reaches 2.6 x 10(-5) S m(-1) at 3 wt% carbon nanofibre loading, which is an increase of ten orders of magnitude over the pure PS matrix, indicating that the composite is electrically conductive at a very low nanofibre loading. The dielectric properties of carbon nanofibre-PS composites were investigated at room temperature within the Ku-band (frequency range: 12.4-18 GHz). The results reveal that the dielectric constants of the composites are slightly dependent on the frequency but increase rapidly with increasing carbon nanofibre loading in the composite. The experimental data show that the dielectric constant of carbon nanofibre-PS composite can reach more than 80 at a frequency of 15 GHz. C1 Old Dominion Univ, Appl Res Ctr, Newport News, VA 23606 USA. NASA Langley Res Ctr, Electromagnet Res Branch, Hampton, VA 23681 USA. RP Gupta, MC (reprint author), Old Dominion Univ, Appl Res Ctr, Newport News, VA 23606 USA. EM mgupta@odu.edu NR 29 TC 43 Z9 44 U1 1 U2 18 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD NOV PY 2004 VL 15 IS 11 BP 1545 EP 1548 AR PII S0957-4484(04)81475-2 DI 10.1088/0957-4484/15/11/030 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 876PK UT WOS:000225509200030 ER PT J AU Khare, BN Wilhite, P Meyyappan, M AF Khare, BN Wilhite, P Meyyappan, M TI The fluorination of single wall carbon nanotubes using microwave plasma SO NANOTECHNOLOGY LA English DT Article ID GLOW-DISCHARGE; FUNCTIONALIZATION AB We have functionalized single-walled carbon nanotubes using a CF4 microwave discharge and characterized the samples through in situ FTIR spectroscopy, UV-VIS-NIR spectroscopy, FT-Raman spectroscopy, SEM and x-ray photoelectron spectroscopy. A high degree of functionalization is achieved in a very short time frame, demonstrating that a microwave plasma scheme is an efficient technique for surface modification of carbon nanotubes. The analysis indicates a fractional surface coverage of 2/3 with fluorination. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Khare, BN (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. NR 21 TC 50 Z9 52 U1 3 U2 18 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD NOV PY 2004 VL 15 IS 11 BP 1650 EP 1654 AR PII S0957-4484(04)84029-7 DI 10.1088/0957-4484/15/11/048 PG 5 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 876PK UT WOS:000225509200048 ER PT J AU Aires, F Prigent, C Rossow, WB AF Aires, F Prigent, C Rossow, WB TI Neural network uncertainty assessment using Bayesian statistics: A remote sensing application SO NEURAL COMPUTATION LA English DT Article ID RETRIEVAL; SURFACE; MICROWAVE; LAND; TEMPERATURE; SSM/I AB Neural network (NN) techniques have proved successful for many regression problems, in particular for remote sensing; however, uncertainty estimates are rarely provided. In this article, a Bayesian technique to evaluate uncertainties of the NN parameters (i.e., synaptic weights) is first presented. In contrast to more traditional approaches based on point estimation of the NN weights, we assess uncertainties on such estimates to monitor the robustness of the NN model. These theoretical developments are illustrated by applying them to the problem of retrieving surface skin temperature, microwave surface emissivities, and integrated water vapor content from a combined analysis of satellite microwave and infrared observations over land. The weight uncertainty estimates are then used to compute analytically the uncertainties in the network outputs (i.e., error bars and correlation structure of these errors). Such quantities are very important for evaluating any application of an NN model. The uncertainties on the NN Jacobians are then considered in the third part of this article. Used for regression fitting, NN models can be used effectively to represent highly nonlinear, multivariate functions. In this situation, most emphasis is put on estimating the output errors, but almost no attention has been given to errors associated with the internal structure of the regression model. The complex structure of dependency inside the NN is the essence of the model, and assessing its quality, coherency, and physical character makes all the difference between a blackbox model with small output errors and a reliable, robust, and physically coherent model. Such dependency structures are described to the first order by the NN Jacobians: they indicate the sensitivity of one output with respect to the inputs of the model for given input data. We use a Monte Carlo integration procedure to estimate the robustness of the NN Jacobians. A regularization strategy based on principal component analysis is proposed to suppress the multicollinearities in order to make these Jacobians robust and physically meaningful. C1 Columbia Univ, Dept Appl Phys & Appl Math, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Ecole Polytech, CNRS IPSL, Lab Meteorol Dynam, F-91128 Palaiseau, France. Observ Paris, CNRS, LERMA, F-75014 Paris, France. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Aires, F (reprint author), Columbia Univ, Dept Appl Phys & Appl Math, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. EM faires@giss.nasa.gov; eatherine.prigent@obspm.fr; wrossow@giss.nasa.gov RI Rossow, William/F-3138-2015 NR 35 TC 21 Z9 21 U1 0 U2 4 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 USA SN 0899-7667 J9 NEURAL COMPUT JI Neural Comput. PD NOV PY 2004 VL 16 IS 11 BP 2415 EP 2458 DI 10.1162/0899766041941925 PG 44 WC Computer Science, Artificial Intelligence SC Computer Science GA 859EU UT WOS:000224247000008 PM 15476606 ER PT J AU Stecker, FW AF Stecker, FW TI Ultrahigh energy cosmic rays: Old physics or new physics? SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT Cosmic Ray International Seminar on GZK and Surroundings (CRIS 2004) CY MAY 31-JUN 06, 2004 CL Catania, ITALY ID ZATSEPIN-KUZMIN CUTOFF; STRONGLY INTERACTING NEUTRINOS; SUPERHEAVY DARK-MATTER; LUMINOSITY FUNCTION; PARTICLE PHYSICS; AIR-SHOWERS; GAMMA-RAYS; BURSTS; SPECTRUM; UNIVERSE AB We consider the advantages of and the problems associated with hypotheses to explain the origin of ultrahigh energy cosmic rays (UHECR: E > 10 EeV) and the "trans-GZK" cosmic rays (TGZK: E > 100 EeV) both through "old physics" (acceleration in cosmic sources) and "new physics" (new particles, topological defects, fat neutrino cross sections, Lorentz invariance violation). C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Stecker, FW (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RI Stecker, Floyd/D-3169-2012 NR 79 TC 2 Z9 2 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 NOV PY 2004 VL 136 BP 309 EP 318 DI 10.1016/j.nuclphysbps.2004.10.028 PG 10 WC Physics, Particles & Fields SC Physics GA 887IU UT WOS:000226300000039 ER PT J AU Stecker, FW Krizmanic, JF Barbier, LM Loh, E Mitchell, JW Sokolsky, P Streitmatter, RE AF Stecker, FW Krizmanic, JF Barbier, LM Loh, E Mitchell, JW Sokolsky, P Streitmatter, RE TI Observing the ultrahigh energy universe with OWL eyes SO NUCLEAR PHYSICS B-PROCEEDINGS SUPPLEMENTS LA English DT Article; Proceedings Paper CT Cosmic Ray Internation Seminsr on GZK and Surroundings (CRIS 2004) CY MAY 31-JUN 06, 2004 CL Catania, ITALY ID SPACE; CLOUDS AB The goal of the Orbiting Wide-field Light-collectors (OWL) mission is to study the origin and physics of the highest energy particles known in nature, the ultrahigh energy cosmic rays (UHECRs). The OWL mission consists of telescopes with UV sensitive cameras on two satellites operating in tandem to view in stereo the development of the giant particle showers induced in the Earth's atmosphere by UHECRs. This paper discusses the characteristics of the OWL mission. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Natl Sci Fdn, Arlington, VA 22230 USA. Univ Utah, High Energy Astrophys Inst, Salt Lake City, UT 84112 USA. RP Stecker, FW (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RI Stecker, Floyd/D-3169-2012 NR 7 TC 37 Z9 38 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 NOV PY 2004 VL 136 BP 433 EP 438 DI 10.1016/j.nuclphysbps.2004.10.027 PG 6 WC Physics, Particles & Fields SC Physics GA 887IU UT WOS:000226300000055 ER PT J AU Wang, XH Wang, B Pouch, J Miranda, F Anderson, JE Bos, PJ AF Wang, XH Wang, B Pouch, J Miranda, F Anderson, JE Bos, PJ TI Performance evaluation of a liquid-crystal-on-silicon spatial light modulator SO OPTICAL ENGINEERING LA English DT Article ID BEAM-STEERING DEVICES; OPTICS AB 2-D optical phased array antennas formed by a liquid crystal on silicon (LCOS) spatial light modulator are described for free-space laser communication and high-resolution wavefront control. The device consists of an 2-D array of 1024x768 phase modulator elements, each with controlled voltage, and can induce a phase shift from 0 to 2pi for wavelengths up to the near IR. When the device is used as a wavefront corrector, 18.7 waves peak-valley (at 632.8 nm) of aberration in the optical system is corrected to a residual of 1/9 wave peak-valley, or 1/30 wave rms. The Strehl ratio improved from 0.006 to 0.83 after correction. An additional linear phase ramp was added to the correction phase ramp to simultaneously correct and steer the laser beam. Continuous steering over +/-4 mrad in the X-Y plane with a steering accuracy higher than 10 murad has been obtained. The 1-D beam-steering efficiency is 80% at the maximum steering angle of 4 mrad. These results suggest that an LCOS device can be used to achieve very high-resolution wavefront control at very high efficiency. (C) 2004 Society of Photo-Optical Instrumentation Engineers. C1 Kent State Univ, Inst Liquid Crystal, Kent, OH 44242 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Hana Microdisplay Technol Inc, Twinsburg, OH 44087 USA. RP Wang, XH (reprint author), Kent State Univ, Inst Liquid Crystal, Kent, OH 44242 USA. EM pbos@kent.edu NR 9 TC 37 Z9 40 U1 2 U2 10 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD NOV PY 2004 VL 43 IS 11 BP 2769 EP 2774 DI 10.1117/1.1794706 PG 6 WC Optics SC Optics GA 873AB UT WOS:000225249900045 ER PT J AU Samara, GA Barnes, CE AF Samara, GA Barnes, CE TI Effects of pressure on deep levels in semiconductors: The MFe center in InP SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 11th International Conference on High-Pressure Semiconductor Physics (HPSP-11) CY AUG 02-05, 2004 CL Berkeley, CA ID RELAXATION; DEFECT AB This work investigated the effects of hydrostatic pressure on the properties and bistability of the scientifically challenging and technologically important deep MFe center in iron (Fe)-doped, n-type indium phosphide (InP). When occupied by electrons, the center can be reversibly placed in either of two configurations, termed A and B, by the proper choice of electric biasing conditions and temperature. Pressure has a very large influence on the balance between these two configurations, favoring A over B. Above 8 kbar essentially only the A configuration is observed. This result, along with detailed studies of the effects of pressure on the energetics of the two configurations and on the kinetics of the B --> A transformation, provide important new insights about the nature of the two configurations and their associated deep levels. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Samara, GA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM gasamar@sandia.gov NR 8 TC 1 Z9 1 U1 2 U2 2 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD NOV PY 2004 VL 241 IS 14 BP 3293 EP 3299 DI 10.1002/pssb.200405213 PG 7 WC Physics, Condensed Matter SC Physics GA 875LR UT WOS:000225422300034 ER PT J AU Di Rienzi, J Drachman, RJ AF Di Rienzi, J Drachman, RJ TI Approximating the target wave function in positronium-helium scattering SO PHYSICAL REVIEW A LA English DT Article ID ORTHOPOSITRONIUM; XE; KR; NE AB We consider the effect of using necessarily inexact target wave functions in a Kohn variational calculation of the Ps-He scattering length. We use the simplest closed-shell or one-term Hylleraas function in the static-exchange approximation and examine two plausible ways of handling such an inexact function. Both of these methods have been employed in the past, and our results are compared with these previous calculations. Significant differences are found which may persist in more elaborate calculations. C1 Coll Notre Dame Maryland, Baltimore, MD 21210 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Di Rienzi, J (reprint author), Coll Notre Dame Maryland, Baltimore, MD 21210 USA. NR 11 TC 3 Z9 3 U1 0 U2 4 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 NOV PY 2004 VL 70 IS 5 AR 052706 DI 10.1103/PhysRevA.70.052706 PG 5 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 876EM UT WOS:000225479000076 ER PT J AU Savchenkov, AA Ilchenko, VS Matsko, AB Maleki, L AF Savchenkov, AA Ilchenko, VS Matsko, AB Maleki, L TI Kilohertz optical resonances in dielectric crystal cavities SO PHYSICAL REVIEW A LA English DT Article ID FUSED-SILICA MICROSPHERES; RAYLEIGH-SCATTERING; LIGHT; MICROCAVITIES; RESONATORS; STORAGE; SLOW AB We experimentally demonstrate a crystalline CaF2 optical whispering gallery mode resonator characterized by the quality factor Q>2x10(10) at lambda=1.319 mum. We also report the demonstration of ultrahigh-Q resonators of lithium niobate and lithium tantalate (Q>2x10(8)), and sapphire (Q>10(9)). We discuss fundamental limits of the Q factor, and application of such resonators for measurement of ultrasmall optical losses in various materials. We further analyze the observation of thermo-optical instability in whispering gallery modes of crystalline resonators. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Savchenkov, AA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Matsko, Andrey/A-1272-2007 NR 26 TC 122 Z9 123 U1 2 U2 23 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 NOV PY 2004 VL 70 IS 5 AR 051804 DI 10.1103/PhysRevA.70.051804 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 876EM UT WOS:000225479000014 ER PT J AU Buonanno, A Chen, YB Pan, Y Vallisneri, M AF Buonanno, A Chen, YB Pan, Y Vallisneri, M TI Quasiphysical family of gravity-wave templates for precessing binaries of spinning compact objects: Application to double-spin precessing binaries SO PHYSICAL REVIEW D LA English DT Article ID POST-NEWTONIAN ORDER; GRAVITATIONAL-WAVES; COALESCING BINARIES; LASER-INTERFEROMETER; INSPIRALING BINARIES; SEARCH TEMPLATES; ENERGY-LOSS; SYSTEMS; RADIATION; FILTERS AB The gravitational waveforms emitted during the adiabatic inspiral of precessing binaries with two spinning compact bodies of comparable masses, evaluated within the post-Newtonian approximation, can be reproduced rather accurately by the waveforms obtained by setting one of the two spins to zero, at least for the purpose of detection by ground-based gravitational-wave interferometers. Here we propose to use this quasiphysical family of single-spin templates to search for the signals emitted by double-spin precessing binaries, and we find that its signal-matching performance is satisfactory for source masses (m(1),m(2))is an element of[3,15]Mx[3,15]M. For this mass range, using the LIGO-I design sensitivity, we estimate that the number of templates required to yield a minimum match of 0.97 is similar to320 000. We discuss also the accuracy to which the single-spin template family can be used to estimate the parameters of the original double-spin precessing binaries. C1 CNRS, Inst Astrophys Paris, Grp Graviatat & Cosmol, F-75014 Paris, France. CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CNRS, Inst Astrophys Paris, Grp Graviatat & Cosmol, 98 Blvd Arago, F-75014 Paris, France. RI Chen, Yanbei/A-2604-2013 NR 59 TC 50 Z9 50 U1 2 U2 2 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 NOV PY 2004 VL 70 IS 10 AR 104003 DI 10.1103/PhysRevD.70.104003 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 875SB UT WOS:000225440900044 ER PT J AU Sylvestre, J AF Sylvestre, J TI Simulations of laser locking to a LISA arm SO PHYSICAL REVIEW D LA English DT Article AB We present detailed numerical simulations of a laser phase stabilization scheme for Laser Interferometer Space Antenna (LISA), where both lasers emitting along one arm are locked to each other. Including the standard secondary noises and spacecraft motions that approximately mimic LISA's orbit (excluding the rotation of the constellation), we verify that very stable laser phases can be obtained and that time delay interferometry can be used to remove the laser phase noise from measurements of gravitational wave strains. Most importantly, we show that this locking scheme can provide significant simplifications over LISA's baseline design in the implementation of time delay interferometry. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, LIGO Lab, Pasadena, CA 91125 USA. RP Sylvestre, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM jsylvest@ligo.caltech.edu RI Sylvestre, Julien/A-8610-2009 OI Sylvestre, Julien/0000-0001-8136-4348 NR 11 TC 11 Z9 11 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 NOV PY 2004 VL 70 IS 10 AR 102002 DI 10.1103/PhysRevD.70.102002 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 875SB UT WOS:000225440900007 ER PT J AU Metzger, PT AF Metzger, PT TI Granular contact force density of states and entropy in a modified Edwards ensemble SO PHYSICAL REVIEW E LA English DT Article ID STRESS-RESPONSE FUNCTION; STATISTICAL-MECHANICS; THEORETICAL-MODEL; ELONGATED GRAINS; BEAD PACKS; TRANSMISSION; FLUCTUATIONS; SYSTEMS; MATTER; MEDIA AB A method has been found to analyze Edwards' granular contact force probability functional for a special case. As a result, the granular contact force probability density functions are obtained from first principles for this case. The results are in excellent agreement with the experimental and simulation data. The derivation assumes Edwards' flat measure-a density of states (DOS) that is uniform within the metastable regions of phase space. The enabling assumption, supported by physical arguments and empirical evidence, is that correlating information is not significantly recursive through loops in the packing. Maximizing a state-counting entropy results in a transport equation that can be solved numerically. For the present this has been done using the "mean-structure approximation," projecting the DOS across all angular coordinates to more clearly identify its predominant nominiformities. These features are (1) the grain factor T related to grain stability and strong correlation between the contact forces on the same grain and (2) the structure factor (Y) over bar related to Newton's third law and strong correlation between neighboring grains. C1 NASA, KSC Appl Phys Lab, John F Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. RP Metzger, PT (reprint author), NASA, KSC Appl Phys Lab, John F Kennedy Space Ctr, YA-C3-E, Kennedy Space Ctr, FL 32899 USA. EM Philip.T.Metzger@nasa.gov RI Metzger, Philip/R-3136-2016 OI Metzger, Philip/0000-0002-6871-5358 NR 87 TC 34 Z9 34 U1 1 U2 2 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 NOV PY 2004 VL 70 IS 5 AR 051303 DI 10.1103/PhysRevE.70.051303 PN 1 PG 19 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 882WG UT WOS:000225970500024 PM 15600599 ER PT J AU He, GW Wang, M Lele, SK AF He, GW Wang, M Lele, SK TI On the computation of space-time correlations by large-eddy simulation SO PHYSICS OF FLUIDS LA English DT Article ID ISOTROPIC TURBULENCE; NOISE; SOUND; SCALES AB The effect of subgrid-scale (SGS) modeling on velocity (space-) time correlations is investigated in decaying isotropic turbulence. The performance of several SGS models is evaluated, which shows superiority of the dynamic Smagorinsky model used in conjunction with the multiscale large-eddy simulation (LES) procedure. Compared to the results of direct numerical simulation, LES is shown to underpredict the (un-normalized) correlation magnitude and slightly overpredict the decorrelation time scales. This can lead to inaccurate solutions in applications such as aeroacoustics. The underprediction of correlation functions is particularly severe for higher wavenumber modes which are swept by the most energetic modes. The classic sweeping hypothesis for stationary turbulence is generalized for decaying turbulence and used to analyze the observed discrepancies. Based on this analysis, the time correlations are determined by the wavenumber energy spectra and the sweeping velocity, which is the square root of the total energy. Hence, an accurate prediction of the instantaneous energy spectra is most critical to the accurate computation of time correlations. (C) 2004 American Institute of Physics. C1 Stanford Univ, Ctr Turbulence Res, NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Chinese Acad Sci, Inst Mech, LNM, Beijing 100080, Peoples R China. Stanford Univ, Dept Aeronaut & Astronaut, Stanford, CA 94305 USA. Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA. RP He, GW (reprint author), Stanford Univ, Ctr Turbulence Res, NASA, Ames Res Ctr, MS 19-44, Moffett Field, CA 94035 USA. EM wangm@stanford.edu RI Wang, Meng/C-1622-2012 NR 29 TC 33 Z9 36 U1 0 U2 8 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD NOV PY 2004 VL 16 IS 11 BP 3859 EP 3867 DI 10.1063/1.1779251 PG 9 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 861ZH UT WOS:000224456800006 ER PT J AU Hughes, TJR Wells, GN Wray, AA AF Hughes, TJR Wells, GN Wray, AA TI Energy transfers and spectral eddy viscosity in large-eddy simulations of homogeneous isotropic turbulence: Comparison of dynamic Smagorinsky and multiscale models over a range of discretizations SO PHYSICS OF FLUIDS LA English DT Article ID FLOWS AB Energy transfers within large-eddy simulation (LES) and direct numerical simulation (DNS) grids are studied. The spectral eddy viscosity for conventional dynamic Smagorinsky and variational multiscale LES methods are compared with DNS results. Both models underestimate the DNS results for a very coarse LES, but the dynamic Smagorinsky model is significantly better. For moderately to well-refined LES, the dynamic Smagorinsky model overestimates the spectral eddy viscosity at low wave numbers. The multiscale model is in good agreement with DNS for these cases. The convergence of the multiscale model to the DNS with grid refinement is more rapid than for the dynamic Smagorinsky model. (C) 2004 American Institute of Physics. C1 Univ Texas, Austin, TX 78735 USA. Delft Univ Technol, Fac Civil Engn & Geosci, NL-2628 CN Delft, Netherlands. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hughes, TJR (reprint author), Univ Texas, 201 E 24th St,ACES 6-412,1 Univ Stn C0200, Austin, TX 78735 USA. RI Wells, Garth/C-6375-2011 OI Wells, Garth/0000-0001-5291-7951 NR 24 TC 27 Z9 27 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 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD NOV PY 2004 VL 16 IS 11 BP 4044 EP 4052 DI 10.1063/1.1789157 PG 9 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 861ZH UT WOS:000224456800023 ER PT J AU Boswell, RW Sutherland, O Charles, C Squire, JP Diaz, FRC Glover, TW Jacobson, VT Chavers, DG Bengtson, RD Bering, EA Goulding, RH Light, M AF Boswell, RW Sutherland, O Charles, C Squire, JP Diaz, FRC Glover, TW Jacobson, VT Chavers, DG Bengtson, RD Bering, EA Goulding, RH Light, M TI Experimental evidence of parametric decay processes in the variable specific impulse magnetoplasma rocket (VASIMR) helicon plasma source SO PHYSICS OF PLASMAS LA English DT Article ID LOWER HYBRID FREQUENCY; WHISTLER WAVES AB Decay waves have been observed in the megahertz range in the helium plasma generated by the variable specific impulse magnetoplasma rocket magnetoplasma thruster. They are measured using one of the tips of a triple probe connected to a 50 Omega input of a spectrum analyzer via a dc block (a small capacitor). The maximum amplitude of all waves is in the center of the plasma and does not appear correlated to the radial electron density or temperature profiles. The waves seem to be generated close to the helicon antenna that was 91 cm "upstream" from the measuring Langmuir probe. A possible explanation is parametric decay of the large amplitude helicon wave that also generates the plasma. (C) 2004 American Institute of Physics. C1 Australian Natl Univ, Space Plasma & Plasma Proc Grp, PRL RSPhysSE, Canberra, ACT 0200, Australia. NASA, Lyndon B Johnson Space Ctr, Adv Space Propuls Lab, Houston, TX 77058 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Texas, Austin, TX 78712 USA. Univ Houston, Houston, TX USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP Boswell, RW (reprint author), Australian Natl Univ, Space Plasma & Plasma Proc Grp, PRL RSPhysSE, Canberra, ACT 0200, Australia. RI Charles, Christine/C-2826-2009 NR 11 TC 13 Z9 13 U1 4 U2 16 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD NOV PY 2004 VL 11 IS 11 BP 5125 EP 5129 DI 10.1063/1.1803579 PG 5 WC Physics, Fluids & Plasmas SC Physics GA 867QC UT WOS:000224856100028 ER PT J AU Casani, JR AF Casani, JR TI William Hayward Pickering SO PHYSICS TODAY LA English DT Biographical-Item C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Casani, JR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD NOV PY 2004 VL 57 IS 11 BP 86 EP 87 DI 10.1063/1.1839390 PG 2 WC Physics, Multidisciplinary SC Physics GA 867WJ UT WOS:000224873100034 ER PT J AU Towner, MC Patel, MR Ringrose, TJ Zarnecki, JC Pullan, D Sims, MR Haapanala, S Harri, AM Polkko, J Wilson, CF Zent, AP Quinn, RC Grunthaner, FJ Hecht, MH Garry, JRC AF Towner, MC Patel, MR Ringrose, TJ Zarnecki, JC Pullan, D Sims, MR Haapanala, S Harri, AM Polkko, J Wilson, CF Zent, AP Quinn, RC Grunthaner, FJ Hecht, MH Garry, JRC TI The Beagle 2 environmental sensors: science goals and instrument description SO PLANETARY AND SPACE SCIENCE LA English DT Article DE Mars; instrumentation; environment; boundary layer ID MARS PATHFINDER; MARTIAN ATMOSPHERE; DUST DEVILS; LANDER; VORTICES; SURFACE; SIMULATIONS; REACTIVITY; RADIATION; MISSION AB A suite of instruments on the Beagle 2 Mars lander was designed and built in order to investigate the environmental conditions at the landing site. The sensor suite was capable of measuring air temperature at two heights, surface level pressure, wind speed and direction, saltated particle momentum, UV flux (diffuse and direct at five wavelengths), the total accumulated radiation dose and investigating the nature of the oxidising environment. The scientific goals of the instruments are discussed within the context of current understanding of the environmental conditions on Mars, and the instruments themselves are described in detail. Beagle 2 landed on Mars in late 2003, as part of the ESA Mars Express mission. The expected lifetime of the lander on the surface was 180 sols, with a landing site in Isidis Planitia, but has not responded to attempts to contact it, and has now been declared lost. The Environmental Sensor Suite (ESS) was intended to monitor and characterise the current local meteorological parameters, investigating specific areas of scientific interest raised from previous missions, most notably dust transport and transient phenomena, and additionally to add context to the conditions that any possible martian micro-organisms would have to face. The design of the instrument suite was strongly influenced by mass limitations, with eight sensor subsystems having a total mass of approximately 100 g. Although Beagle 2 has been now declared lost, the scientific goals of an Environmental Sensors Suite still remain a valid target for any future astrobiology orientated missions. (C) 2004 Elsevier Ltd. All rights reserved. C1 Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. Univ Leicester, Dept Phys & Astron, Ctr Space Res, Leicester LE1 7RH, Leics, England. Finnish Meteorol Inst, Geophys Res Div, FIN-00101 Helsinki, Finland. Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. SETI Inst, Mountain View, CA 94035 USA. Jet Prop Lab, Pasadena, CA 91109 USA. Gorlaeus Labs, Leiden Inst Chem, SCM, Astrobiol Grp, NL-2300 RA Leiden, Netherlands. RP Towner, MC (reprint author), Open Univ, Planetary & Space Sci Res Inst, Walton Hall, Milton Keynes MK7 6AA, Bucks, England. EM m.c.towner@open.ac.uk RI Harri, Ari-Matti/C-7142-2012 OI Harri, Ari-Matti/0000-0001-8541-2802 NR 43 TC 11 Z9 11 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD NOV PY 2004 VL 52 IS 13 BP 1141 EP 1156 DI 10.1016/j.pss.2004.07.015 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 873VW UT WOS:000225310500001 ER PT J AU Bose, D Govindan, TR Meyyappan, M AF Bose, D Govindan, TR Meyyappan, M TI Modelling of magnetic field profile effects in a helicon source SO PLASMA SOURCES SCIENCE & TECHNOLOGY LA English DT Article ID ACTIVATED REACTIVE EVAPORATION; PLASMA SOURCE; GENERALIZED THEORY; WAVE-PROPAGATION; COUPLED PLASMA; ABSORPTION; ENERGY; EXCITATION; DEPOSITION; SILICON AB The effect of altering the dc magnetic field on plasma properties and wave characteristics in a helicon source is studied. A two-dimensional, numerical model with self-consistency between wave propagation, including the Trivelpiece-Gould mode, and plasma transport is used. A parametric study is carried out to ascertain the magnetic field profile effects on wave propagation, peripheral versus bulk power absorption, plasma density, uniformity, temperature and potential. It is found that diffusion of plasma and power absorption away from the radio frequency antenna can be enhanced by adjusting the magnetic field profile. The effect on plasma uniformity qualitatively agrees with the measured data in the literature. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM dbose@arc.nasa.gov NR 24 TC 0 Z9 0 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0963-0252 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD NOV PY 2004 VL 13 IS 4 BP 553 EP 561 AR PII S0963-0252(04)83154-2 DI 10.1088/0963-0252/13/4/001 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 875LJ UT WOS:000225421400002 ER PT J AU Bol'shakov, AA Cruden, BA Sharma, SP AF Bol'shakov, AA Cruden, BA Sharma, SP TI Determination of gas temperature and thermometric species in inductively coupled plasmas by emission and diode laser absorption SO PLASMA SOURCES SCIENCE & TECHNOLOGY LA English DT Article ID ATOMIC FLUORESCENCE SPECTROMETRY; SURFACE-EMITTING LASERS; EXCITED-STATE DENSITIES; SEMICONDUCTOR-LASER; REFERENCE CELL; RATE CONSTANTS; ARGON; DISCHARGE; PRESSURE; SPECTROSCOPY AB A vertical cavity surface-emitting laser diode (VCSEL) was used as a spectrally tunable emission source for measurements of the radial-integrated gas temperature inside an inductively coupled plasma reactor. The data were obtained by profiling the Doppler-broadened absorption of metastable Ar atoms at 763.51 nm in argon and argon/nitrogen plasmas (3%, 45%, and 90% N-2 in Ar) at pressures of 0.5-70 Pa and inductive powers of 100 and 300 W. The results were compared to the rotational temperature derived from the N-2 emission at the (0,0) vibrational transition of the C(3)Pi(u)-B(3)Pi(g) system. The differences in integrated rotational and Doppler temperatures were attributed to non-uniform spatial distributions of both temperature and thermometric species (Ar* and N-2*) that varied depending on the conditions. A two-dimensional, three-temperature fluid plasma simulation was employed to explain these differences. This work should facilitate further development of a miniature sensor for non-intrusive acquisition of data (temperature and densities of multiple plasma species) during micro- and nano-fabrication plasma processing, thus enabling diagnostic-assisted continuous optimization and advanced control over the processes. Such sensors would also enable us to track the origins and pathways of damaging contaminants, thereby providing real-time feedback for adjustment of processes. Our work serves as an example of how two line-of-sight integrated temperatures derived from different thermometric species make it possible to characterize the radial non-uniformity of the plasma. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Bol'shakov, AA (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM bcruden@niail.arc.nasa.gov RI Bol'shakov, Alexander/A-9258-2015 OI Bol'shakov, Alexander/0000-0002-6034-7079 NR 54 TC 22 Z9 22 U1 1 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0963-0252 EI 1361-6595 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD NOV PY 2004 VL 13 IS 4 BP 691 EP 700 AR PII S0963-0252(04)87555-8 DI 10.1088/0963-0252/13/4/019 PG 10 WC Physics, Fluids & Plasmas SC Physics GA 875LJ UT WOS:000225421400020 ER PT J AU Klein, DJ Bryant, RG AF Klein, DJ Bryant, RG TI Synthesis and characterization of polyamides derived from cyano-containing 1,4-bis(4-aminophenoxy)benzene monomers SO POLYMER BULLETIN LA English DT Article ID FERROELECTRIC BEHAVIOR; FILMS AB A series of potentially electroactive aromatic-aliphatic polyamides based upon 3,6-bis(2-cyano-4-aminophenoxy)phthalonitrile (1) was synthesized in N,N-dimethylacetamide to yield polymers with intrinsic viscosities of 0.66-1.04 dL/g. One polyamide was synthesized using 1,4-bis(2-cyano-4-aminophenoxy)benzene (2) to compare to 1. There appears to be an odd-even effect of methylene spacer length upon the mechanical properties and glass transition temperature, with an even number of methylene groups yielding the larger values. Thermogravimetric analysis in air and nitrogen showed that these polymers had similar 5% weight losses in both atmospheres, which indicated that oxygen is not involved in the initial degradation of these polymers. C1 NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. RP Klein, DJ (reprint author), NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. EM d.j.klein@larc.nasa.gov NR 12 TC 4 Z9 4 U1 1 U2 5 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0170-0839 J9 POLYM BULL JI Polym. Bull. PD NOV PY 2004 VL 52 IS 5 BP 307 EP 314 DI 10.1007/s00289-004-0290-0 PG 8 WC Polymer Science SC Polymer Science GA 868UM UT WOS:000224938500001 ER PT J AU Hwang, D AF Hwang, D TI Review of research into the concept of the microblowing technique for turbulent skin friction reduction SO PROGRESS IN AEROSPACE SCIENCES LA English DT Review ID ADVERSE PRESSURE-GRADIENT; BOUNDARY-LAYER; INJECTION; RIBLETS; PLATE AB A new technology for reducing turbulent skin friction, called the Microblowing Technique (MBT), is presented. Results from proof-of-concept experiments show that this technology could potentially reduce turbulent skin friction by more than 50% of the skin friction of a solid flat plate for subsonic and supersonic flow conditions. The primary purpose of this review paper is to provide readers with information on the turbulent skin friction reduction obtained from many experiments using the MBT. Although the MBT has a penalty for obtaining the microblowing air associated with it, some combinations of the MBT with suction boundary layer control-methods are an attractive alternative for a real application. Several computational simulations to understand the flow physics of the MBT are also included. More experiments and computational fluid dynamic (CFD) computations are needed for the understanding of the unsteady flow nature of the MBT and the optimization of this new technology. Published by Elsevier Ltd. C1 NASA, Glenn Res Ctr, Turbomachinery & Prop Syst Div, Inlet Branch, Cleveland, OH 44135 USA. RP Hwang, D (reprint author), NASA, Glenn Res Ctr, Turbomachinery & Prop Syst Div, Inlet Branch, 21000 Brookpk Rd, Cleveland, OH 44135 USA. EM danny.p.hwang@nasa.gov NR 38 TC 10 Z9 12 U1 2 U2 7 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 NOV PY 2004 VL 40 IS 8 BP 559 EP 575 DI 10.1016/j.paerosci.2005.01.002 PG 17 WC Engineering, Aerospace SC Engineering GA 918IF UT WOS:000228534800003 ER PT J AU Schmidt, GA Shindell, DT Miller, RL Mann, ME Rind, D AF Schmidt, GA Shindell, DT Miller, RL Mann, ME Rind, D TI General circulation modelling of Holocene climate variability SO QUATERNARY SCIENCE REVIEWS LA English DT Article; Proceedings Paper CT IMAGES Holocene Working Group Workshop CY AUG 27-30, 2003 CL Hafslo, NORWAY SP NOAA Climate Change Data & Detect Program, Swiss Natl Sci Fdn ID NORTH-ATLANTIC OSCILLATION; SURFACE AIR-TEMPERATURE; TREE-RING CHRONOLOGIES; LAST 1000 YEARS; SOLAR IRRADIANCE; MAUNDER MINIMUM; THERMOHALINE CIRCULATION; ATMOSPHERIC CO2; COLD EVENT; ICE CORE AB Results from a series of Goddard Institute for Space Studies (GISS) General Circulation Models (GCMs) are used to assess climate variability in the pre-anthropogenic Holocene, the interval following the end of the last glacial beginning roughly 11.5 kyr BP. In particular, we focus on the forced aspects of this variability. The principle forcings are orbital, solar, volcanic and events (such as the 8.2 kyr BP event). Land use and greenhouse gases also play a small role. We discuss suitable comparisons to paleo-data and the appropriateness of model experimental design for single and multiple forcing runs using time-slices and transient simulations. As an example, we focus on the response to solar and volcanic forcing in the context of the Maunder Minimum, a cool period of the late 17th century and demonstrate that although (northern) hemispheric mean temperature changes can be reasonably simulated in most models, the details of regional patterns depend more heavily on the included physics. In particular, we highlight the role of the stratosphere as well as the importance of ocean and vegetation feedbacks. (C) 2004 Elsevier Ltd. All rights reserved. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY 10027 USA. Columbia Univ, Dept Appl Math & Phys, New York, NY 10027 USA. Univ Virginia, Dept Environm Studies, Charlottesville, VA USA. RP NASA, Goddard Inst Space Studies, New York, NY 10025 USA. EM gschmidt@giss.nasa.gov; dshindell@giss.nasa.gov; rmiller@giss.nasa.gov; mann@virginia.edu; drind@giss.nasa.gov RI Shindell, Drew/D-4636-2012; Schmidt, Gavin/D-4427-2012; Miller, Ron/E-1902-2012; Mann, Michael/B-8472-2017 OI Schmidt, Gavin/0000-0002-2258-0486; Mann, Michael/0000-0003-3067-296X NR 89 TC 30 Z9 31 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0277-3791 J9 QUATERNARY SCI REV JI Quat. Sci. Rev. PD NOV PY 2004 VL 23 IS 20-22 BP 2167 EP 2181 DI 10.1016/j.quascirev.2004.08.005 PG 15 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 864QO UT WOS:000224648200010 ER PT J AU Porter, AL Yglesias, E Kongthon, A Courseault, C Newman, NC AF Porter, AL Yglesias, E Kongthon, A Courseault, C Newman, NC TI Get what you need from technology information products SO RESEARCH-TECHNOLOGY MANAGEMENT LA English DT Editorial Material ID KNOWLEDGE C1 Search Technol Inc, R&D, Atlanta, GA USA. Georgia Inst Technol, Technol Policy & Assessment Ctr, Atlanta, GA 30332 USA. Georgia Inst Technol, Sch Ind & Syst Engn, Atlanta, GA 30332 USA. Georgia Inst Technol, Sch Publ Policy, Atlanta, GA 30332 USA. NASA, Peer Review Serv, Washington, DC 20546 USA. Univ New Orleans, New Orleans, LA 70148 USA. IISC, Atlanta, GA USA. RP Porter, AL (reprint author), Search Technol Inc, R&D, Atlanta, GA USA. EM Alan.porter@isye.gatech.edu; newman@iisco.com RI Kongthon, Alisa /E-4470-2011; Yglesias, Elmer/I-3265-2013; porter, alan/A-7013-2009 OI porter, alan/0000-0002-4520-6518 NR 10 TC 5 Z9 5 U1 0 U2 0 PU INDUSTRIAL RESEARCH INST INC PI WASHINGTON PA 1550 M ST., NW, WASHINGTON, DC 20005 USA SN 0895-6308 J9 RES TECHNOL MANAGE JI Res.-Technol. Manage. PD NOV-DEC PY 2004 VL 47 IS 6 BP 16 EP 19 PG 4 WC Business; Engineering, Industrial; Management SC Business & Economics; Engineering GA 867MI UT WOS:000224846300007 ER PT J AU Lawrence, JK Cadavid, AC Ruzmaikin, A AF Lawrence, JK Cadavid, AC Ruzmaikin, A TI Principal component analysis of the solar magnetic field I: The axisymmetric field at the photosphere SO SOLAR PHYSICS LA English DT Article ID CYCLE AB A principal component analysis, or proper orthogonal decomposition, of the axisymmetric magnetic field at the photosphere is carried out to find an optimal representation of the observed solar cycle. The 22-year periodic field requires just two modes. NSO Kitt Peak synoptic maps for Carrington rotations 1664-2007 were reduced by taking both the mean and the median field over longitude to produce two sequences of functions of sine latitude spanning 25.7 years. The lowest modes of each are determined by the polar fields. The mean field is most efficient at representing the periodic field, but the median field is more efficient at representing the evolution of the diffuse field patterns. C1 Calif State Univ Northridge, Northridge, CA 91330 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lawrence, JK (reprint author), Calif State Univ Northridge, Northridge, CA 91330 USA. EM john.lawrence@csun.edu NR 16 TC 12 Z9 12 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD NOV PY 2004 VL 225 IS 1 BP 1 EP 19 DI 10.1007/s11207-004-3257-2 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 913TK UT WOS:000228175900001 ER PT J AU Cliver, EW Nitta, NV Thompson, BJ Zhang, J AF Cliver, EW Nitta, NV Thompson, BJ Zhang, J TI Coronal shocks of November 1997 revisited: The Cme-type II timing problem SO SOLAR PHYSICS LA English DT Review ID WIND SPACECRAFT DATA; WAVELENGTH RADIO-BURSTS; MASS EJECTION EVENTS; GOPALSWAMY,N. ET-AL; SOLAR-FLARE WAVES; X-RAY; INTERPLANETARY SHOCKS; EIT WAVES; H-ALPHA; SOHO/EIT OBSERVATIONS AB We re-examine observations bearing on the origin of metric type II bursts for six impulsive solar events in November 1997. Previous analyses of these events indicated that the metric type IIs were due to flares ( either blast waves or ejecta). Our point of departure was the study of Zhang et al. ( 2001) based on the Large Angle and Spectrometric Coronagraph's C1 instrument ( occulting disk at 1.1 R-0) that identified the rapid acceleration phase of coronal mass ejections (CMEs) with the rise phase of soft X-ray light curves of associated flares. We find that the inferred onset of rapid CME acceleration in each of the six cases occurred 1 - 3 min before the onset of metric type II emission, in contrast to the results of previous studies for certain of these events that obtained CME launch times similar to 25 - 45 min earlier than type II onset. The removal of the CME-metric type II timing discrepancy in these events and, more generally, the identification of the onset of the rapid acceleration phase of CMEs with the flare impulsive phase undercuts a significant argument against CMEs as metric type II shock drivers. In general, the six events exhibited: ( 1) ample evidence of dynamic behavior [ soft X-ray ejecta, extreme ultra-violet imaging telescope (EIT) dimming onsets, and wave initiation ( observed variously in H alpha, EUV, and soft X-rays)] during the inferred fast acceleration phases of the CMEs, consistent with the cataclysmic disruption of the low solar atmosphere one would expect to be associated with a CME; and ( 2) an organic relationship between EIT dimmings ( generally taken to be source regions of CMEs) and EIT waves ( which are highly associated with metric type II bursts) indicative of a CME-driver scenario. Our analysis indicates that the broad (similar to 90 degrees to halo) CMEs observed in the outer LASCO coronagraphs for these impulsive events began life as relatively small-scale structures, with angular spans of similar to 15 degrees in the low corona. A review of on-going work bearing on other aspects ( than timing) of the question of the origin of metric type II bursts ( CME association; connectivity of metric and decametric-hectometric type II shocks; spatial relationship between CMEs and metric shocks) leads to the conclusion that CMEs remain a strong candidate to be the principal/sole driver of metric type II shocks vis-a-vis flare blast waves/ejecta. C1 USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. Lockheed Martin Solar & Astrophys Lab, Palo Alto, CA 94304 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. George Mason Univ, Ctr Earth Observing & Space Res, Fairfax, VA 22030 USA. RP Cliver, EW (reprint author), USAF, Res Lab, Space Vehicles Directorate, Hanscom AFB, MA 01731 USA. EM edward.cliver@hanscom.af.mil; nitta@lmsal.com; barbara.j.thompson@nasa.gov; jiez@scs.gmu.edu RI Thompson, Barbara/C-9429-2012 NR 133 TC 65 Z9 65 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD NOV PY 2004 VL 225 IS 1 BP 105 EP 139 DI 10.1007/s11207-004-3258-1 PG 35 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 913TK UT WOS:000228175900007 ER PT J AU De Moortel, I McAteer, RTJ AF De Moortel, I McAteer, RTJ TI Waves and wavelets: An automated detection technique for solar oscillations SO SOLAR PHYSICS LA English DT Article ID MAGNETOACOUSTIC WAVES; CORONAL LOOPS; CHROMOSPHERE; TRACE; EIT AB This paper investigates the possibility of automating the detection of propagating intensity perturbations in coronal loops using wavelet analysis. Two different sets of TRACE 171 images are studied using the automated wavelet routine presented by McAteer et al. (2004). Both localised, short-lived periodicities and sustained, periodic, oscillations are picked up by the routine, with the results dependent to a large extent on the signal-to-noise ratio of the dataset. At present, the automation is only partial; the relevance of the detected periodicity and the identification of the coronal structure supporting it still have to be determined by the user, as does the judging of the accuracy of the results. Care has to be taken when interpreting the results of the wavelet analysis, and a good knowledge of all possible factors that might influence or distort the results is a necessity. Despite these limitations, wavelet analysis can play an important role in automatically identifying a variety of phenomena and in the analysis of the ever-growing ( observational or simulated) datasets. C1 Univ St Andrews, Sch Math & Stat, St Andrews KY16 9SS, Fife, Scotland. NASA, Goddard Space Flight Ctr, Solar Phys Branch, Greenbelt, MD 20771 USA. Queens Univ Belfast, Dept Pure & Appl Phys, Belfast BT7 1NN, Antrim, North Ireland. RP Univ St Andrews, Sch Math & Stat, St Andrews KY16 9SS, Fife, Scotland. EM ineke@mcs.st-and.ac.uk; j.mcateer@grasshopper.gsfc.nasa.gov RI McAteer, R. T. James/D-3736-2011 NR 15 TC 13 Z9 13 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 EI 1573-093X J9 SOL PHYS JI Sol. Phys. PD NOV PY 2004 VL 223 IS 1 BP 1 EP 11 DI 10.1007/s11207-004-0806-7 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 902EK UT WOS:000227336600001 ER PT J AU Verwichte, E Nakariakov, VM Ofman, L Deluca, EE AF Verwichte, E Nakariakov, VM Ofman, L Deluca, EE TI Characteristics of transverse oscillations in a coronal loop arcade SO SOLAR PHYSICS LA English DT Article ID MAGNETOHYDRODYNAMIC WAVES; NUMERICAL SIMULATIONS; RESONANT ABSORPTION; TRANSITION-REGION; TRACE; EXPLORER; FLARE; HOT AB TRACE observations from 15 April 2001 of transverse oscillations in coronal loops of a post-flare loop arcade are investigated. They are considered to be standing fast kink oscillations. Oscillation signatures such as displacement amplitude, period, phase and damping time are deduced from 9 loops as a function of distance along the loop length. Multiple oscillation modes are found with different amplitude profile along the loop length, suggesting the presence of a second harmonic. The damping times are consistent with the hypothesis of phase mixing and resonant absorption, although there is a clear bias towards longer damping times compared with previous studies. The coronal magnetic field strength and coronal shear viscosity in the loop arcade are derived. C1 Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Catholic Univ Amer, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Verwichte, E (reprint author), Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. RI Nakariakov, Valery/E-2375-2013; Lee, SungHwan/O-2563-2013; DeLuca, Edward/L-7534-2013 OI Nakariakov, Valery/0000-0001-6423-8286; DeLuca, Edward/0000-0001-7416-2895 NR 30 TC 171 Z9 172 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 NOV PY 2004 VL 223 IS 1 BP 77 EP 94 DI 10.1007/s11207-004-0807-6 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 902EK UT WOS:000227336600006 ER PT J AU Liewer, PC Neugebauer, M Zurbuchen, T AF Liewer, PC Neugebauer, M Zurbuchen, T TI Characteristics of active-region sources of solar wind near solar maximum SO SOLAR PHYSICS LA English DT Article ID OPEN MAGNETIC-FIELDS; SUNSPOT MAXIMUM; ULYSSES; ORIGIN; FLUX AB Previous studies of the source regions of solar wind sampled by ACE and Ulysses showed that some solar wind originates from open magnetic flux rooted in active regions. These solar wind sources were labeled active-region sources when the open flux was from a strong field region with no corresponding coronal hole in the NSO He 10830 Angstrom synoptic coronal-hole maps. Here, we present a detailed investigation of several of these active-region sources using ACE and Ulysses solar wind data, potential field models of the corona, and solar imaging data. We find that the solar wind from these active-region sources has distinct signatures, e. g., it generally has a higher oxygen charge state than wind associated with helium-10830 Angstrom coronal-hole sources, indicating a hotter source region, consistent with the active region source interpretation. We compare the magnetic topology of the open field lines of these active-region sources with images of the hot corona to search for corresponding features in EUV and soft X-ray images. In most, but not all, cases, a dark area is seen in the EUV and soft X-ray image as for familiar coronal-hole sources. However, in one case no dark area was evident in the soft X-ray images: the magnetic model showed a double dipole coronal structure consistent with the images, both indicating that the footpoints of the open field lines, rooted deep within the active region, lay near the separatrix between loops connecting to two different opposite polarity regions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48105 USA. RP Liewer, PC (reprint author), CALTECH, Jet Prop Lab, Mail Stop 169-506, Pasadena, CA 91109 USA. EM paulett.liewer@jpl.nasa.gov; mneugeb@lpl.arizona.edu; thomasz@umich.edu NR 28 TC 68 Z9 68 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD NOV PY 2004 VL 223 IS 1 BP 209 EP 229 DI 10.1007/s11207-004-1105-z PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 902EK UT WOS:000227336600014 ER PT J AU Vieira, LEA Gonzalez, WD Echer, E Tsurutani, BT AF Vieira, LEA Gonzalez, WD Echer, E Tsurutani, BT TI Storm-intensity criteria for several classes of the driving interplanetary structures SO SOLAR PHYSICS LA English DT Article ID MAGNETIC CLOUDS; GEOMAGNETIC STORMS; PHASE; SOLAR; ORIGIN; FIELDS; SPACE AB In this paper we discuss the main-phase evolution of intense magnetic storms, associated with the passage of different interplanetary magnetic structures. It is shown that their evolution, driven by intense magnetic fields in the sheath region just behind interplanetary shocks, evolves faster ( implying physically different magnetospheric configurations) than that associated with intense magnetic fields in the ejecta itself and in corotating streams. The estimated ring-current injection rate for the main phase of intense magnetic storms caused by sheath fields is similar to10 times greater than the estimated injection rate for N-S magnetic clouds. Based on these results, we propose storm-intensity criteria for several classes of the driving interplanetary structures. The time necessary to reach a Dst/SYM index threshold level is an important parameter for a space weather forecast. C1 Inst Nacl Pesquisas Espaciais, Sao Paulo, Brazil. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Vieira, LEA (reprint author), Inst Nacl Pesquisas Espaciais, Sao Paulo, Brazil. RI Vieira, Luis Eduardo/A-5548-2008 OI Vieira, Luis Eduardo/0000-0002-9376-475X NR 28 TC 21 Z9 21 U1 1 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD NOV PY 2004 VL 223 IS 1 BP 245 EP 258 DI 10.1007/s11207-004-1108-9 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 902EK UT WOS:000227336600016 ER PT J AU Stadd, C Bingham, J AF Stadd, C Bingham, J TI The US civil space sector: alternate futures SO SPACE POLICY LA English DT Article AB The initiation of a new vision for exploration, as articulated by US President George W. Bush on 14 January 2004, has excited much interest. This article analyzes the dynamics and potential for changes in the processes and participants in future space policy and space exploration activities. It examines a range of possible alternative paths for NASA and the US government's space exploration activities, the international space community and the private sector in the articulation and pursuit of future space exploration endeavors. it concludes that the new vision for exploration brings about both an opportunity and indeed a necessity for movement towards new and innovative methods and institutions for the effective conduct of multidimensional and multilateral space exploration activities in the future. (C) 2004 Elsevier Ltd. All rights reserved. C1 Capitol Solut, Bethesda, MD 20814 USA. NASA, Manassas, VA 20110 USA. RP Bingham, J (reprint author), Capitol Solut, 5618 Oldchester Rd, Bethesda, MD 20814 USA. EM cstadd@comcast.net; jbingham1@msn.com NR 23 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0265-9646 J9 SPACE POLICY JI Space Policy PD NOV PY 2004 VL 20 IS 4 BP 241 EP 252 DI 10.1016/j.spacepol.2004.08.001 PG 12 WC International Relations; Social Sciences, Interdisciplinary SC International Relations; Social Sciences - Other Topics GA 877XS UT WOS:000225609700002 ER PT J AU Zhu, H Sankar, BV Haftka, RT Venkataraman, S Blosser, M AF Zhu, H Sankar, BV Haftka, RT Venkataraman, S Blosser, M TI Optimization of functionally graded metallic foam insulation under transient heat transfer conditions SO STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION LA English DT Article DE functionally graded materials; metallic foam; optimization; thermal protection systems AB The problem of minimizing the maximum temperature of a structure insulated by a functionally graded metal foam insulation under transient heat conduction is studied. First, the performance of insulation designed for steady-state conditions is compared with uniform solidity insulation. It is found that the optimum steady-state insulation performs poorly under transient conditions. Then, the maximum structural temperature of a two-layer insulation with constant solidity for each layer is minimized by varying the solidity profile for a given total thickness and mass. It is found that the cooler inner layer of the optimal design has high solidity, while the hotter outer layer has low solidity. This is in contrast to the steady-state optimum, where the solidity profile is the reverse. C1 Univ Florida, Dept Mech & Aerosp Engn, Gainesville, FL 32611 USA. San Diego State Univ, Dept Aerosp Engn & Engn Mech, San Diego, CA 92182 USA. NASA, Langley Res Ctr, Met & Thermal Struct Branch, Hampton, VA 23681 USA. RP Sankar, BV (reprint author), Univ Florida, Dept Mech & Aerosp Engn, Gainesville, FL 32611 USA. EM sankar@ufl.edu RI Sankar, Bhavani/F-5193-2011; OI Sankar, Bhavani/0000-0002-4556-1982 NR 4 TC 13 Z9 13 U1 0 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1615-147X J9 STRUCT MULTIDISCIP O JI Struct. Multidiscip. Optim. PD NOV PY 2004 VL 28 IS 5 BP 349 EP 355 DI 10.1007/s00158-004-0463-3 PG 7 WC Computer Science, Interdisciplinary Applications; Engineering, Multidisciplinary; Mechanics SC Computer Science; Engineering; Mechanics GA 870JF UT WOS:000225052700005 ER PT J AU Zhu, DM Fox, DS Miller, RA Ghosn, LJ Kalluri, S AF Zhu, DM Fox, DS Miller, RA Ghosn, LJ Kalluri, S TI Effect of surface impulsive thermal loads on fatigue behavior of constant volume propulsion engine combustor materials SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 31st International Conference on Metallurgical Coatings and Thin Films CY APR 19-23, 2004 CL San Diego, CA SP AVS Sci & Technol Soc, Adv Surface Engn Div DE laser-impulsive high-cycle and low-cycle fatigue; surface crack initiation and propagation; oxidation damage; stress concentration; fatigue strength AB The development of advanced high-performance constant-volume-combustion-cycle engines (CVCCE) requires robust design of the engine components that are capable of enduring harsh combustion environments under high-frequency thermal and mechanical fatigue conditions. In this study, a simulated engine test rig has been established to evaluate thermal fatigue behavior of a candidate engine combustor material, Haynes 188, under superimposed CO2 laser surface impulsive thermal loads (30-100 Hz) in conjunction with the mechanical fatigue loads (10 Hz). The mechanical high-cycle fatigue (HCF) testing of some laser preexposed specimens has also been conducted at 100 Hz to determine the laser surface damage effect. The test results have indicated that material surface oxidation- and creep-enhanced fatigue is an important mechanism for the surface crack initiation and propagation under the simulated CVCCE engine conditions. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, John H Glenn Res Ctr Lewis Field, Surface & Protect Coatings Branch, Cleveland, OH 44135 USA. RP Zhu, DM (reprint author), NASA, John H Glenn Res Ctr Lewis Field, Surface & Protect Coatings Branch, 5160,21000 Brookpk Rd,Mail Stop 24-1, Cleveland, OH 44135 USA. EM Dongming.Zhu@grc.nasa.gov NR 7 TC 10 Z9 10 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD NOV-DEC PY 2004 VL 188 BP 13 EP 19 DI 10.1016/j.surfcoat.2004.07.101 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 872YQ UT WOS:000225245800004 ER PT J AU Zhu, DM Choi, SR Miller, RA AF Zhu, DM Choi, SR Miller, RA TI Development and thermal fatigue testing of ceramic thermal barrier coatings SO SURFACE & COATINGS TECHNOLOGY LA English DT Article; Proceedings Paper CT 31st International Conference on Metallurgical Coatings and Thin Films CY APR 19-23, 2004 CL San Diego, CA SP AVS Sci & Technol Soc, Adv Surface Engn Div DE thermal barrier coatings; thermal conductivity; thermal fatigue; high power laser; crack propagation; coating spallation; life prediction ID TEMPERATURE DEFORMATION; MECHANICAL-PROPERTIES; CREEP-BEHAVIOR; CONDUCTIVITY; STRESS AB Ceramic thermal barrier coatings (TBCs) will play an increasingly important role in future gas turbine engines because of their ability to effectively protect the engine components and further raise engine temperatures. Durability of the coating systems remains a critical issue with the ever-increasing temperature requirements. Thermal conductivity increase and coating degradation due to sintering and phase changes are known to be detrimental to coating performance. There is a need to characterize the coating thermal fatigue behavior and temperature limit, in order to potentially take full advantage of the current coating capability. In this study, a laser thermal fatigue test technique has been used to study the delamination crack propagation of thermal barrier coatings under simulated engine heat flux heating and thermal cyclic loading. Thermal conductivity and cyclic fatigue behaviors of plasma-sprayed ZrO2-8 wt-% Y2O3 thermal barrier coatings were evaluated under high temperature, large thermal gradient and thermal cycling conditions. The coating degradation and failure processes were assessed by real-time monitoring of the coating thermal conductivity during the testing. The test results showed that the initial average crack propagation rates of ZrO2-8 Wt-% Y2O3 coatings were in the range of 3-8 mum/cycle. The crack propagation rates increased to 30-40 mum/cycle at later stages of testing, and the critical spalling crack size ranged from 3 to 5 mm for the coatings. The accelerated crack growth is attributed to the increased driving force for crack propagation under the laser heat flux cyclic test conditions. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Johns H Gleen Res Ctr, Surface & Protect Coatings Branch, Cleveland, OH 44135 USA. RP Zhu, DM (reprint author), NASA, Johns H Gleen Res Ctr, Surface & Protect Coatings Branch, 5160,21000 Brookpk Rd,Mail Stop 24-1, Cleveland, OH 44135 USA. EM Dongming.Zhu@grc.nasa.gov NR 17 TC 37 Z9 39 U1 0 U2 17 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD NOV-DEC PY 2004 VL 188 BP 146 EP 152 DI 10.1016/j.surfcoat.2004.08.017 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 872YQ UT WOS:000225245800023 ER PT J AU Gupta, ML Douglass, AR Kawa, R Pawson, S AF Gupta, ML Douglass, AR Kawa, R Pawson, S TI Use of radon for evaluation of atmospheric transport models: sensitivity to emissions SO TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY LA English DT Article ID GLOBAL-MODELS; RN-222; SIMULATION; TRACERS; STRATOSPHERE; TROPOSPHERE; VALIDATION; DEPOSITION; CHEMISTRY; PROFILES AB We present comparative analyses of atmospheric radon (Rn) distributions simulated using different emission scenarios and the observations. Results indicate that the model generally reproduces observed distributions of Rn but there are some biases in the model related to differences in large-scale and convective transport. Simulations presented here use an off-line three-dimensional chemical transport model driven by assimilated winds and two scenarios of Rn fluxes (atom cm(-2) s(-1)) from ice-free land surfaces: (A) globally uniform flux of 1.0 within +/-60degrees and 0.5 within 60degreesN-70degreesN and (B) uniform flux of 1.0 between 60degreesS and 30degreesN followed by a sharp linear decrease to 0.2 at 70degreesN. We considered an additional scenario (C) where Rn emissions for case A were uniformly reduced by 28%. Results show that case A overpredicts observed Rn distributions in both hemispheres. Simulated Northern Hemisphere Rn distributions from cases B and C compare better with the observations, but are not discernible from each other. In the Southern Hemisphere, surface Rn distributions from case C compare better with the observations. We performed a synoptic-scale source-receptor analysis for surface Rn to locate regions with ratios B/A and B/C less than 0.5. Considering the maximum uncertainty in regional Rn emissions of a factor of 2, our analysis indicates that additional measurements of surface Rn, particularly during April-October and north of 50degreesN over the Pacific as well as Atlantic regions, would make it possible to determine if the proposed latitude gradient in Rn emissions is superior to a uniform flux scenario. C1 NASA, Goddard Space Flight Ctr, GEST, GMAO, Greenbelt, MD 20771 USA. RP Gupta, ML (reprint author), NASA, Goddard Space Flight Ctr, GEST, GMAO, Code 916, Greenbelt, MD 20771 USA. EM gupta@code9l6.gsfc.nasa.gov RI Douglass, Anne/D-4655-2012; Kawa, Stephan/E-9040-2012; Pawson, Steven/I-1865-2014 OI Pawson, Steven/0000-0003-0200-717X NR 30 TC 18 Z9 18 U1 1 U2 9 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0280-6509 J9 TELLUS B JI Tellus Ser. B-Chem. Phys. Meteorol. PD NOV PY 2004 VL 56 IS 5 BP 404 EP 412 DI 10.1111/j.1600-0889.2004.00124.x PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 875ZK UT WOS:000225463000002 ER PT J AU Liu, CX Harcombe, PA Knox, RG AF Liu, CX Harcombe, PA Knox, RG TI Structural changes after prescribed fire in woody plant communities of southeastern Texas SO TEXAS JOURNAL OF SCIENCE LA English DT Article; Proceedings Paper CT 3rd Big Thicket Science Conference on Biodiveresity and Ecology of the West Gulf Coastal Plain Landsscape CY OCT 09-11, 2003 CL Beaumont, TX ID LONGLEAF PINE SAVANNAS; LAKE WALES RIDGE; FLORIDA; FOREST; VEGETATION; FREQUENCY; USA; RESILIENCE AB A field experiment was conducted to study fire effects on woody plants in vegetation representing a gradient from dry to mesic types in southeastern Texas. There was little effect of fire on small sapling density or shrub cover, partly because post-fire recruitment of saplings by resprouting and germination was rapid. Fire caused declines in large saplings and small trees in most types, and in large trees in the drier vegetation types. That is, this study showed that fire effects varied according to vegetation type and stem size class; the effects were most pronounced for dry types and small trees. The effect of fire on stem density was lower in the mesic types probably because of differences in moisture, fuel characteristics, and species response. C1 Rice Univ, Houston, TX 77251 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Liu, CX (reprint author), 1527 Weiskopf Loop, Round Rock, TX 78664 USA. EM harcomb@rice.edu RI Knox, Robert/E-9657-2011 NR 31 TC 1 Z9 1 U1 0 U2 3 PU TEXAS ACAD SCI PI LUBBOCK PA BOX 43151, LUBBOCK, TX 79409-3151 USA SN 0040-4403 J9 TEX J SCI JI Tex. J. Sci. PD NOV PY 2004 VL 56 IS 4 BP 319 EP 334 PG 16 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA 931WM UT WOS:000229516200004 ER PT J AU Gatski, TB AF Gatski, TB TI Constitutive equations for turbulent flows SO THEORETICAL AND COMPUTATIONAL FLUID DYNAMICS LA English DT Article DE turbulence modeling; incompressible flows; RANS modeling; constitutive equation ID REYNOLDS STRESS MODEL; NEAR-WALL TURBULENCE; PRESSURE-STRAIN CORRELATION; BOUNDARY-LAYER; CLOSURE MODELS; TRANSPORT-EQUATIONS; DISSIPATION RATE; EDDY-VISCOSITY; CHANNEL FLOW; NUMBER AB This review is intended to provide both the specialist and non-specialist in the field of turbulence with a continuum mechanics perspective on developing closure models needed in the description of turbulent flows. Modeling considerations applicable to isothermal, incompressible turbulent flows are discussed within the framework of Reynolds-averaged transport equations for the statistical moments. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Gatski, TB (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. EM t.b.gatski@larc.nasa.gov NR 73 TC 13 Z9 13 U1 0 U2 7 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 NOV PY 2004 VL 18 IS 5 BP 345 EP 369 DI 10.1007/s00162-004-0119-3 PG 25 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 872WF UT WOS:000225239200002 ER PT J AU Miyoshi, K Street, KW AF Miyoshi, K Street, KW TI Novel carbons in tribology SO TRIBOLOGY INTERNATIONAL LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Miyoshi, K (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM Kazuhisa.Miyoshi-1@nasa.gov NR 17 TC 9 Z9 9 U1 1 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0301-679X J9 TRIBOL INT JI Tribol. Int. PD NOV-DEC PY 2004 VL 37 IS 11-12 BP 865 EP 868 DI 10.1016/j.triboint.2004.07.001 PG 4 WC Engineering, Mechanical SC Engineering GA 869SE UT WOS:000225003600001 ER PT J AU DellaCorte, C AF DellaCorte, C TI Wanted dead or alive? 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 NOV PY 2004 VL 60 IS 11 BP 6 EP 6 PG 1 WC Engineering, Mechanical SC Engineering GA 869GO UT WOS:000224971600002 ER PT J AU Sherwood, SC Minnis, P McGill, M AF Sherwood, SC Minnis, P McGill, M TI Deep convective cloud-top heights and their thermodynamic control during CRYSTAL-FACE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE convection; tropical meteorology; tropopause ID TROPICAL WESTERN PACIFIC; VERTICAL VELOCITY; SOUTH FLORIDA; SEA-BREEZE; MICROPHYSICAL EVOLUTION; OCEANIC CONVECTION; TROPOPAUSE; MODEL; RAINFALL; CUMULONIMBUS AB [1] Infrared (11 mum) radiances from GOES-8 and local radiosonde profiles, collected during the Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment ( CRYSTAL-FACE) in July 2002, are used to assess the vertical distribution of Florida-area deep convective cloud-top height and test predictions as to its variation based on parcel theory. The highest infrared tops (Z(11)) reached approximately to the cold point at 15.4 km, though these are uncertain by about 1 km due to unknown cloud-environment temperature differences. Since lidar shows that visible "tops'' are generally 1 km or more above Z(11), visible cloud tops frequently penetrated the lapse-rate tropopause( similar to 15 km). Further, since tropospheric ice concentrations were typically present up to similar to 1 km above the visible tops, lofting of moisture through the mean cold point was probably common. Morning clouds, and those near Key West, rarely penetrated the tropopause. As in previous studies, nonentraining parcel theory fails to explain either of these results, though it does show promise in explaining day-to-day variations over the peninsula. Moisture variations above the boundary layer account for much of the day-to-day Z(11) variability, especially over the oceans. In all locations a 20% increase in mean mixing ratio between 750 and 500 hPa was associated with about 1 km deeper maximum cloud penetration, other things being equal. This sensitivity is too large to explain by simple dilution of parcel buoyancy through mixing, implying microphysical or dynamical feedbacks on cloud development. The evident influence of midtropospheric humidity on the depth of the tropical troposphere suggests an interesting climate feedback possibility for stabilizing midtropospheric relative humidity. C1 Yale Univ, Dept Geol & Geophys, New Haven, CT 06520 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Sherwood, SC (reprint author), Yale Univ, Dept Geol & Geophys, POB 6666, New Haven, CT 06520 USA. EM ssherwood@alum.mit.edu RI Sherwood, Steven/B-5673-2008; McGill, Matthew/D-8176-2012; Minnis, Patrick/G-1902-2010 OI Sherwood, Steven/0000-0001-7420-8216; Minnis, Patrick/0000-0002-4733-6148 NR 42 TC 26 Z9 26 U1 0 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 OCT 30 PY 2004 VL 109 IS D20 AR D20119 DI 10.1029/2004JD004811 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 867ZX UT WOS:000224882700005 ER PT J AU Knobelspiesse, KD Pietras, C Fargion, GS Wang, MH Frouin, R Miller, MA Subramaniam, A Balch, WM AF Knobelspiesse, KD Pietras, C Fargion, GS Wang, MH Frouin, R Miller, MA Subramaniam, A Balch, WM TI Maritime aerosol optical thickness measured by handheld sun photometers SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE maritime aerosols; Angstrom exponent; aerosol optical thickness; sun photometer ID SKY RADIANCE; LOGNORMAL-DISTRIBUTION; RETRIEVAL; OCEAN; SCATTERING; DEPTH; VARIABILITY; PERFORMANCE; SIMULATIONS; INSTRUMENT AB For several years, the NASA SIMBIOS Project has collected, processed, and archived optical aerosol data from shipboard sun photometers. The calibration, processing, quality control, and archival methodology for handheld sun photometers are described here, along with their deployment statistics. Data processing has been standardized for all instruments by using identical calibration methods, ancillary data, and processing software. Statistical analysis reveals a dataset influenced by its temporal and geographic distribution, while multimodal histograms for aerosol optical thickness (AOT) and Angstrom exponent reveal varied aerosol populations. A K-means unsupervised classification technique is used to separate these populations. This separation is validated by showing individual classes are more likely to be log-normally (for AOTs) or normally (for Angstrom exponents) distributed than the dataset as a whole. Properties for each class are presented, along with the characteristics of each class by regional oceanic basin. Results also compare favorably with maritime aerosols measured by land-based AERONET Cimels in island sites, while providing data coverage in previously sparsely sampled regions. Aerosol models employed by SeaWiFS (Sea-Viewing Wide Field-of-View Sensor) also compare favorably with these ground based measurements. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Maryland Baltimore, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Greenbelt, MD USA. Sci Syst & Applicat Corp, Greenbelt, MD USA. Univ Maryland Baltimore Cty, Baltimore, MD 21228 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92103 USA. Brookhaven Natl Lab, Upton, NY USA. Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. Bigelow Lab Ocean Sci, W Boothbay Harbor, ME USA. RP Knobelspiesse, KD (reprint author), Univ Maryland Baltimore, NASA, Goddard Space Flight Ctr, Code 970-2, Greenbelt, MD 20771 USA. EM kirk@simbios.gsfc.nasa.gov; wang@simbios.gsfc.nasa.gov RI Wang, Menghua/F-5631-2010; Knobelspiesse, Kirk/S-5902-2016; OI Wang, Menghua/0000-0001-7019-3125; Knobelspiesse, Kirk/0000-0001-5986-1751; Subramaniam, Ajit/0000-0003-1316-5827 NR 44 TC 54 Z9 58 U1 1 U2 5 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 OCT 30 PY 2004 VL 93 IS 1-2 BP 87 EP 106 DI 10.1016/j.rse.2004.06.018 PG 20 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 859UW UT WOS:000224294400008 ER PT J AU Miller, RL McKee, BA AF Miller, RL McKee, BA TI Using MODIS Terra 250 m imagery to map concentrations of total suspended matter in coastal waters SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE total suspended matter; MODIS; remote sensing ID CORAL GROWTH; PHYTOPLANKTON; SEDIMENTS; SEAWIFS; PRODUCTIVITY; MISSISSIPPI; ESTUARIES; TURBIDITY; SHELF AB High concentrations of suspended particulate matter in coastal waters directly affect or govern numerous water column and benthic processes. The concentration of suspended sediments derived from bottom sediment resuspension or discharge of sediment-laden rivers is highly variable over a wide range of time and space scales. Although there has been considerable effort to use remotely sensed images to provide synoptic maps of suspended particulate matter, there are limited routine applications of this technology due in part to the low spatial resolution, long revisit period, or cost of most remotely sensed data. In contrast, near daily coverage of mediumresolution data is available from the Moderate-resolution Imaging Spectroradiometer (MODIS) Terra instrument without charge from several data distribution gateways. Equally important, several display and processing programs are available that operate on low cost computers. The utility of MODIS 250 m data for analyzing complex coastal waters was examined in the Northern Gulf of Mexico. Using simple processing procedures, MODIS images were used to map the concentration of Total Suspended Matter (TSM). A robust linear relationship was established between band 1 (620-670 nm) MODIS Terra 250 m data and in situ measurements of TSM (r(2) = 0. 89; n = 52; MSE=4.74) acquired during six field campaigns. This study demonstrates that the moderately high resolution of MODIS 250 m data and the operating characteristics of the instrument provide data useful for examining the transport and fate of materials in coastal environments, particularly smaller bodies of water such as bays and estuaries. (C) 2004 Elsevier Inc. All rights reserved. C1 NASA, Earth Sci Applicat Directorate, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. Tulane Univ, Dept Earth & Environm Sci, New Orleans, LA 70118 USA. RP Miller, RL (reprint author), NASA, Earth Sci Applicat Directorate, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. EM richard.l.miller@nasa.gov NR 34 TC 252 Z9 274 U1 4 U2 41 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 OCT 30 PY 2004 VL 93 IS 1-2 BP 259 EP 266 DI 10.1016/j.rse.2004.07.012 PG 8 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 859UW UT WOS:000224294400021 ER PT J AU Niyogi, D Chang, HI Saxena, VK Holt, T Alapaty, K Booker, F Chen, F Davis, KJ Holben, B Matsui, T Meyers, T Oechel, WC Pielke, RA Wells, R Wilson, K Xue, YK AF Niyogi, D Chang, HI Saxena, VK Holt, T Alapaty, K Booker, F Chen, F Davis, KJ Holben, B Matsui, T Meyers, T Oechel, WC Pielke, RA Wells, R Wilson, K Xue, YK TI Direct observations of the effects of aerosol loading on net ecosystem CO2 exchanges over different landscapes SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CARBON-DIOXIDE; PRODUCTIVITY; PINATUBO; FOREST; LIGHT AB We present the first direct, multisite observations in support of the hypothesis that atmospheric aerosols affect the regional terrestrial carbon cycle. The daytime growing season (summer) CO2 flux observations from six sites (forest, grasslands, and croplands) with collocated aerosol and surface radiation measurements were analyzed for high and low diffuse radiation; effect of cloud cover; and effect of high and low aerosol optical depths (AOD). Results indicate that, aerosols exert a significant impact on net CO2 exchange, and their effect may be even more significant than that due to clouds. The response appears to be a general feature irrespective of the landscape and photosynthetic pathway. The CO2 sink increased with aerosol loading for forest and crop lands, and decreased for grassland. The cause for the difference in response between vegetation types is hypothesized to be canopy architecture. C1 N Carolina State Univ, Dept MEAS, Raleigh, NC 27695 USA. USN, Res Lab, Monterey, CA USA. Univ N Carolina, Raleigh, NC 27695 USA. ARS, USDA, Air Qual Plant Growth & Dev Unit, Raleigh, NC 27695 USA. Natl Ctr Atmospher Res, Boulder, CO 80305 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Colorado State Univ, Dept Atmospher Sci, Ft Collins, CO 80523 USA. NOAA, Atmospher Turbulence & Diffus Div, Oak Ridge, TN 37830 USA. San Diego State Univ, San Diego, CA 92182 USA. N Carolina State Univ, Dept Crop Sci, Raleigh, NC 27695 USA. Univ Calif Los Angeles, Dept Geog, Los Angeles, CA 90095 USA. RP Niyogi, D (reprint author), N Carolina State Univ, Dept MEAS, Raleigh, NC 27695 USA. EM dev_niyogi@ncsu.edu RI Pielke, Roger/A-5015-2009; Oechel, Walter/F-9361-2010; Chen, Fei/B-1747-2009; Meyers, Tilden/C-6633-2016 OI Oechel, Walter/0000-0002-3504-026X; NR 13 TC 81 Z9 86 U1 3 U2 32 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 29 PY 2004 VL 31 IS 20 AR L20506 DI 10.1029/2004GL020915 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 867ZK UT WOS:000224881400002 ER PT J AU Dey, S Tripathi, SN Singh, RP Holben, BN AF Dey, S Tripathi, SN Singh, RP Holben, BN TI Influence of dust storms on the aerosol optical properties over the Indo-Gangetic basin SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosol; dust; India ID MID-ATLANTIC COAST; SKY RADIANCE MEASUREMENTS; UNITED-STATES; SIZE DISTRIBUTION; TROPOSPHERIC AEROSOLS; LIGHT-SCATTERING; MINERAL DUST; SAHARAN DUST; ULTRAVIOLET-RADIATION; ATMOSPHERIC DUST AB Dust storms are considered natural hazards, which affect day-to-day life for a short time from a few hours to a few days. They are common in India especially in the western Rajasthan Province, which is covered by the Thar Desert. In this paper, we present the effects of the dust events on the aerosol parameters retrieved over Kanpur ( located in heart of the Indo-Gangetic basin) from ground-based Aerosol Robotic Network (AERONET) measurements. The aerosol parameters show strong seasonal variability in this region, with least spectral dependence of aerosol optical depth (AOD) during the premonsoon season, characterized by dust loading. The aerosol optical properties over the Indo-Gangetic basin are controlled by the diurnal and seasonal cycles of urban pollutants, but the dust storms are so significant that the local cycle is completely overshadowed. A rise in AOD by more than 50% and corresponding decrease in angstrom parameter by 70-90% have been observed after each dust event. The diurnal variations of AOD during the dust events have been found to be controlled by the onset of the dust storms. The changes in the single scattering albedo (SSA) and real n(lambda) and imaginary k(lambda) parts of the refractive index indicate that the 27 May 2002 event influences the optical state to be absorbing, whereas for the other four events the aerosols are found to be dominantly scattering in nature. SSA has been found to increase sharply at higher wavelengths (lambda > 440 nm) during the dust events, whereas n(lambda) and k(lambda) increase 2-3 times more at lambda = 440 nm compared to those at higher wavelengths. The contrasting change in the spectral variations of the optical properties is due to the difference in the nature of the aerosols loading during the events. Aerosol volume concentration at coarse mode is found to increase three times after the dust events, whereas no significant change has been observed in the volume concentration at fine mode. Concentration of the particulate matters less than 10 mum (PM10) is also found to increase by similar to150 mug m(-3) after each dust event except on the 27 May 2002 event, when heavy rainfall after the dust storm washed out the suspended particulate matters from the atmosphere, and the ground level PM10 concentration was not influenced by the advected dust particles on that day. Aerosol index values in successive Total Ozone Mapping Spectrometer (TOMS) images over the region support the characterization of the aerosols in this region in terms of their optical properties, which are being transported over the Indo-Gangetic basin from the western Thar Desert and the Gulf regions depending upon the size of the particles, shown by the air mass trajectories. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Indian Inst Technol, Dept Civil Engn, Kanpur 208016, Uttar Pradesh, India. RP Singh, RP (reprint author), George Mason Univ, Sch Computat Sci, Fairfax, VA 22030 USA. EM sagnik@iitk.ac.in; snt@iitk.ac.in; rsingh3@gmu.edu; brent@aeronet.gsfc.nasa.gov RI Singh, Ramesh/G-7240-2012; Tripathi, Sachchida/J-4840-2016 NR 62 TC 184 Z9 185 U1 3 U2 25 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 29 PY 2004 VL 109 IS D20 AR D20211 DI 10.1029/2004JD004924 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 867ZU UT WOS:000224882400004 ER PT J AU Lui, ATY Hori, T Ohtani, S Zhang, Y Zhou, XY Henderson, MG Mukai, T Hayakawa, H Mende, SB AF Lui, ATY Hori, T Ohtani, S Zhang, Y Zhou, XY Henderson, MG Mukai, T Hayakawa, H Mende, SB TI Magnetotail behavior during storm time "sawtooth injections" SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE sawtooth injections; substorms; magnetotail ID MAGNETIC STORMS; SPACECRAFT; CONVECTION; SUBSTORMS; TAIL AB [1] A series of magnetic storms occurred during 16 - 21 April 2002 with multiple local minima in the Dst index. During this storm period, Geotail traversed the magnetotail from the premidnight tail lobe in the midtail region to the postmidnight plasma sheet in the near-Earth region. Simultaneous observations of energetic particles at the geostationary altitude showed the feature known as "sawtooth injections'' remarkably well from 18 April to 19 April. This conjunction allows us to examine the magnetotail behavior in the tail lobe and the plasma sheet associated with sawtooth injections. In the tail lobe, close but not perfect time coincidence is found between injection onset and start of southward dipping of the magnetic field vector in the tail lobe. Long-duration (1-2 hours) southward dipping in the tail lobe magnetic field appears to be a global behavior of the tail lobe in association with sawtooth injections. In the plasma sheet, intermittent occurrences of plasma flow reversal from sunward to tailward and of magnetic field from northward to southward are found. The duration of southward magnetic field is typically short (1-5 min) within the plasma sheet. There are some sawtooth injections that are not accompanied by any significant changes in plasma sheet parameters ( plasma flows, magnetic and electric fluctuation levels), suggesting the plasma sheet behavior to be localized even in association with sawtooth injections that are global in nature. There was no indication of the magnetotail being driven in a relatively "steady state'' in association with sawtooth injections during this sequence of storms. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Inst Space & Astronaut Sci, Japan Aerosp Explorat Agcy, Kanagawa 2298510, Japan. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Lui, ATY (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. EM tony.lui@jhuapl.edu RI Ohtani, Shinichi/E-3914-2016; Henderson, Michael/A-3948-2011; Zhang, Yongliang/C-2180-2016 OI Ohtani, Shinichi/0000-0002-9565-6840; Henderson, Michael/0000-0003-4975-9029; Zhang, Yongliang/0000-0003-4851-1662 NR 21 TC 27 Z9 27 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 OCT 29 PY 2004 VL 109 IS A10 AR A10215 DI 10.1029/2004JA010543 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 868AL UT WOS:000224884200003 ER PT J AU Ning, CZ AF Ning, CZ TI Two-photon lasers based on intersubband transitions in semiconductor quantum wells SO PHYSICAL REVIEW LETTERS LA English DT Article ID OPTICAL COMMUNICATION; COHERENT STATES; GAIN; INSTABILITY; REALIZATION; AMPLIFIER; EQUATION; WAVE AB We propose to make a two-photon laser based on intersubband (sublevel) transitions in semiconductor nanostructures. The advantages and feasibility of such a two-photon laser are analyzed in detail using the density matrix approach. Both one-photon and two-photon gains in a three subband quantum well structure are studied on the same footing to show how the two-photon gain can be maximized, while the competing one-photon gain is minimized. The results show that a sufficient two-photon gain can be achieved to overcome one-photon competition and the loss of a conventional semiconductor cavity, making intersubband transitions one of the very few feasible approaches to two-photon lasing. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Ning, CZ (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Mail Stop N229-1, Moffett Field, CA 94035 USA. EM cning@mail.arc.nasa.gov RI Ning, C. Z./D-4699-2009 OI Ning, C. Z./0000-0003-4583-8889 NR 28 TC 30 Z9 31 U1 1 U2 5 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 29 PY 2004 VL 93 IS 18 AR 187403 DI 10.1103/PhysRevLett.93.187403 PG 4 WC Physics, Multidisciplinary SC Physics GA 866US UT WOS:000224799500075 PM 15525208 ER PT J AU Muller, JR Aydin, A AF Muller, JR Aydin, A TI Rupture progression along discontinuous oblique fault sets: implications for the Karadere rupture segment of the 1999 Izmit earthquake, and future rupture in the Sea of Marmara SO TECTONOPHYSICS LA English DT Article; Proceedings Paper CT 1st International Symposium on Earth Sciences and Engineering CY MAY 16-18, 2002 CL Istanbul, TURKEY DE fault interaction; fault stepover; Izmit earthquake; Sea of Marmara; Coulomb stress; static stress ID NORTH ANATOLIAN FAULT; INTERSECTING NORMAL FAULTS; STATIC STRESS CHANGES; PULL-APART BASINS; SOUTHERN CALIFORNIA; TURKEY; SLIP; DEFORMATION; PROPAGATION; REFLECTION AB Large earthquakes in strike-slip regimes commonly rupture fault segments that are oblique to each other in both strike and dip. This was the case during the 1999 lzmit earthquake, which mainly ruptured E-W-striking right-lateral faults but also ruptured the N60degreesE-striking Karadere fault at the eastern end of the main rupture. It will also likely be so for any future large fault rupture in the adjacent Sea of Marmara. Our aim here is to characterize the effects of regional stress direction, stress triggering due to rupture, and mechanical slip interaction on the composite rupture process. We examine the failure tendency and slip mechanism on secondary faults that are oblique in strike and dip to a vertical strike-slip fault or "master" fault. For a regional stress field well-oriented for slip on a vertical right-lateral strike-slip fault, we determine that oblique normal faulting is most favored on dipping faults with two different strikes, both of which are oriented clockwise from the strike-slip fault. The orientation closer in strike to the master fault is predicted to slip with right-lateral oblique normal slip, the other one with left-lateral oblique normal slip. The most favored secondary fault orientations depend on the effective coefficient of friction on the faults and the ratio of the vertical stress to the maximum horizontal stress. If the regional stress instead causes left-lateral slip on the vertical master fault, the most favored secondary faults would be oriented counterclockwise from the master fault. For secondary faults striking +/-30degrees oblique to the master fault, right-lateral slip on the master fault brings both these secondary fault orientations closer to the Coulomb condition for shear failure with oblique right-lateral slip. For a secondary fault striking 30degrees counterclockwise, the predicted stress change and the component of reverse slip both increase for shallower-angle dips of the secondary fault. For a secondary fault striking 30degrees clockwise, the predicted stress change decreases but the predicted component of normal slip increases for shallower-angle dips of the secondary fault. When both the vertical master fault and the dipping secondary fault are allowed to slip, mechanical interaction produces sharp gradients or discontinuities in slip across their intersection lines. This can effectively constrain rupture to limited portions of larger faults, depending on the locations of fault intersections. Across the fault intersection line, predicted rakes can vary by >40degrees and the sense of lateral slip can reverse. Application of these results provides a potential explanation for why only a limited portion of the Karadere fault ruptured during the lzmit earthquake. Our results also suggest that the geometries of fault intersection within the Sea of Marmara favor composite rupture of multiple oblique fault segments. (C) 2004 Elsevier B.V. All rights reserved. C1 Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA. RP Muller, JR (reprint author), NASA, Goddard Space Flight Ctr, Geodynam, Code 921, Greenbelt, MD 20771 USA. EM jmuller@core2.gsfc.nasa.gov NR 58 TC 14 Z9 14 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD OCT 29 PY 2004 VL 391 IS 1-4 BP 283 EP 302 DI 10.1016/j.tecto.2004.07.017 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 879WK UT WOS:000225749700013 ER PT J AU Levrard, B Forget, F Montmessin, F Laskar, J AF Levrard, B Forget, F Montmessin, F Laskar, J TI Recent ice-rich deposits formed at high latitudes on Mars by sublimation of unstable equatorial ice during low obliquity SO NATURE LA English DT Article ID CHAOTIC OBLIQUITY; NEAR-SURFACE; GROUND ICE; CLIMATE; CIRCULATION; HYDROGEN; ODYSSEY; AGES AB Observations from the gamma-ray spectrometer instrument suite on the Mars Odyssey spacecraft have been interpreted as indicating the presence of vast reservoirs of near-surface ice in high latitudes of both martian hemispheres(1-5). Ice concentrations are estimated to range from 70 per cent at 60degrees latitude to 100 per cent near the poles, possibly overlain by a few centimetres of ice-free material in most places(4). This result is supported by morphological evidence of metres-thick layered deposits that are rich in water-ice(6-9) and periglacial-like features(10,11) found only difficult to accommodate with such processes(9,13,14). Alternatively, there are suggestions that ice-rich deposits form by transport of ice from polar reservoirs and direct redeposition in high latitudes during periods of higher obliquity(9,13), but these results have been difficult to reproduce with other models. Here we propose instead that, during periods of low obliquity ( less than 25degrees), high-latitude ice deposits form in both hemispheres by direct deposition of ice, as a result of sublimation from an equatorial ice reservoir that formed earlier, during a prolonged high-obliquity excursion. Using the ice accumulation rates estimated from global climate model simulations we show that, over the past ten million years, large variations of Mars' obliquity have allowed the formation of such metres-thick, sedimentary layered deposits in high latitude and polar regions. C1 IMC, CNRS, UMR 8028, F-75014 Paris, France. Univ Paris 06, Meteorol Dynam Lab, F-75005 Paris, France. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Levrard, B (reprint author), ENS Lyon, UCBL, UMR 5570, Lab Planetol & Teledetect, 43 Blvd 11 Novembre 1918, F-69622 Villeurbanne, France. EM blevrard@imcce.fr RI Laskar, Jacques/E-1098-2011 OI Laskar, Jacques/0000-0003-2634-789X NR 30 TC 128 Z9 127 U1 1 U2 15 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD OCT 28 PY 2004 VL 431 IS 7012 BP 1072 EP 1075 DI 10.1038/nature03055 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 865VB UT WOS:000224730800033 PM 15510141 ER PT J AU Dyall, SD Yan, WH Delgadillo-Correa, MG Lunceford, A Loo, JA Clarke, CF Johnson, PJ AF Dyall, SD Yan, WH Delgadillo-Correa, MG Lunceford, A Loo, JA Clarke, CF Johnson, PJ TI Non-mitochondrial complex I proteins in a hydrogenosomal oxidoreductase complex SO NATURE LA English DT Article ID NADH-QUINONE OXIDOREDUCTASE; TRICHOMONAS-VAGINALIS; FERREDOXIN OXIDOREDUCTASE; PARACOCCUS-DENITRIFICANS; ANAEROBIC EUKARYOTES; NUCLEAR GENOMES; MITOCHONDRIA; EVOLUTION; ORIGIN; GENES AB Trichomonas vaginalis is a unicellular microaerophilic eukaryote that lacks mitochondria yet contains an alternative organelle, the hydrogenosome, involved in pyruvate metabolism. Pathways between the two organelles differ substantially: in hydrogenosomes, pyruvate oxidation is catalysed by pyruvate: ferredoxin oxidoreductase (PFOR), with electrons donated to an [ Fe]hydrogenase which produces hydrogen. ATP is generated exclusively by substrate-level phosphorylation in hydrogenosomes, as opposed to oxidative phosphorylation in mitochondria(1). PFOR and hydrogenase are found in eubacteria and amitochondriate eukaryotes, but not in typical mitochondria(2-4). Analyses of mitochondrial genomes indicate that mitochondria have a single endosymbiotic origin from an alpha-proteobacterial-type progenitor(5). The absence of a genome in trichomonad hydrogenosomes(6) precludes such comparisons, leaving the endosymbiotic history of this organelle unclear(7). Although phylogenetic reconstructions of a few proteins indicate that trichomonad hydrogenosomes share a common origin with mitochondria(8-11), others do not(2-4,7). Here we describe a novel NADH dehydrogenase module of respiratory complex I that is coupled to the central hydrogenosomal fermentative pathway to form a hydrogenosomal oxidoreductase complex that seems to function independently of quinones. Phylogenetic analyses of hydrogenosomal complex I-like proteins Ndh51 and Ndh24 reveal that neither has a common origin with mitochondrial homologues. These studies argue against a vertical origin of trichomonad hydrogenosomes from the proto-mitochondrial endosymbiont. C1 Univ Calif Los Angeles, Dept Microbiol Immunol & Mol Genet, Los Angeles, CA 90095 USA. NASA, Astrobiol Inst, Ctr Astrobiol, IGPP, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, David Geffen Sch Med, Dept Biol Chem, Los Angeles, CA 90095 USA. RP Johnson, PJ (reprint author), Univ Calif Los Angeles, Dept Microbiol Immunol & Mol Genet, 1602 Mol Sci Bldg,609 Charles E Young Dr E, Los Angeles, CA 90095 USA. EM johnsonp@ucla.edu NR 30 TC 60 Z9 63 U1 0 U2 8 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD OCT 28 PY 2004 VL 431 IS 7012 BP 1103 EP 1107 DI 10.1038/nature02990 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 865VB UT WOS:000224730800042 PM 15510149 ER PT J AU Vasilkov, AP Joiner, J Yang, K Bhartia, PK AF Vasilkov, AP Joiner, J Yang, K Bhartia, PK TI Improving total column ozone retrievals by using cloud pressures derived from Raman scattering in the UV SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BACKSCATTER ULTRAVIOLET MEASUREMENTS; TROPOSPHERIC OZONE AB The higher spectral resolution, coverage, and sampling of the Aura satellite ozone monitoring instrument (OMI), as compared with the total ozone mapping spectrometer (TOMS) should allow for improved ozone retrievals. By default, the TOMS-like OMI total column ozone algorithm uses climatological cloud-top pressures based on infrared (IR) measurements to estimate the column ozone below the clouds. Alternatively, cloud pressure can be retrieved using atmospheric rotational Raman scattering. The retrieved cloud pressures should be more consistent with assumptions made in the total ozone algorithm. Here, we use data from the global ozone monitoring experiment (GOME) to estimate total ozone using both the IR-climatological and retrieved cloud pressures. The resulting ozone differences can be significant but do not exceed similar to15 DU. Use of the cloud pressure retrievals leads to a smoother distribution of ozone along a satellite track by reducing small spatial irregularities presumably caused by the difference between the retrieved and climatological cloud pressures. C1 Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Vasilkov, AP (reprint author), Sci Syst & Applicat Inc, 10210 Greenbelt Rd,Suite 400, Lanham, MD 20706 USA. EM vassilkov@ssaihq.com RI Joiner, Joanna/D-6264-2012; Bhartia, Pawan/A-4209-2016 OI Bhartia, Pawan/0000-0001-8307-9137 NR 13 TC 18 Z9 18 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 27 PY 2004 VL 31 IS 20 AR L20109 DI 10.1029/2004GL020603 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 867ZF UT WOS:000224880900002 ER PT J AU Rodell, M Famiglietti, JS Chen, J Seneviratne, SI Viterbo, P Holl, S Wilson, CR AF Rodell, M Famiglietti, JS Chen, J Seneviratne, SI Viterbo, P Holl, S Wilson, CR TI Basin scale estimates of evapotranspiration using GRACE and other observations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CLIMATE EXPERIMENT GRACE; WATER STORAGE VARIATIONS; GRAVITY RECOVERY; PRECIPITATION; EVAPORATION; SYSTEM; VARIABILITY; ILLINOIS; BALANCE; MODEL AB Evapotranspiration is integral to studies of the Earth system, yet it is difficult to measure on regional scales. One estimation technique is a terrestrial water budget, i.e., total precipitation minus the sum of evapotranspiration and net runoff equals the change in water storage. Gravity Recovery and Climate Experiment ( GRACE) satellite gravity observations are now enabling closure of this equation by providing the terrestrial water storage change. Equations are presented here for estimating evapotranspiration using observation based information, taking into account the unique nature of GRACE observations. GRACE water storage changes are first substantiated by comparing with results from a land surface model and a combined atmospheric-terrestrial water budget approach. Evapotranspiration is then estimated for 14 time periods over the Mississippi River basin and compared with output from three modeling systems. The GRACE estimates generally lay in the middle of the models and may provide skill in evaluating modeled evapotranspiration. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. Univ Calif Irvine, Dept Earth Syst Sci, Irvine, CA 92697 USA. Univ Texas, Ctr Space Res, Austin, TX 78712 USA. European Ctr Medium Range Weather Forecasts, Reading RG2 9AX, Berks, England. Univ Texas, Dept Geol Sci, Austin, TX 78712 USA. RP Rodell, M (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. EM matthew.rodell@nasa.gov RI Viterbo, Pedro/B-7184-2008; Seneviratne, Sonia/G-8761-2011; Rodell, Matthew/E-4946-2012 OI Viterbo, Pedro/0000-0001-6587-3062; Seneviratne, Sonia/0000-0001-9528-2917; Rodell, Matthew/0000-0003-0106-7437 NR 28 TC 178 Z9 184 U1 3 U2 29 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 26 PY 2004 VL 31 IS 20 AR L20504 DI 10.1029/2004GL020873 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 867ZE UT WOS:000224880800005 ER PT J AU Martin, S Drucker, R Kwok, R Holt, B AF Martin, S Drucker, R Kwok, R Holt, B TI Estimation of the thin ice thickness and heat flux for the Chukchi Sea Alaskan coast polynya from Special Sensor Microwave/Imager data, 1990-2001 SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE Chukchi Sea; coastal polynya; remote sensing ID DENSE WATER PRODUCTION; ST-LAWRENCE-ISLAND; ARCTIC-OCEAN; SHELF; VARIABILITY; TRANSPORT; LAYER AB One of the largest Arctic polynyas occurs along the Alaskan coast of the Chukchi Sea between Cape Lisburne and Point Barrow. For this polynya, a new thin ice thickness algorithm is described that uses the ratio of the vertically and horizontally polarized Special Sensor Microwave/Imager (SSM/I) 37-GHz channels to retrieve the distribution of thicknesses and heat fluxes at a 25-km resolution. Comparison with clear-sky advanced very high resolution radiometer data shows that the SSM/I thicknesses and heat fluxes are valid for ice thicknesses less than 10-20 cm, and comparison with several synthetic aperture radar (SAR) images shows that the 10-cm ice SSM/I ice thickness contour approximately follows the SAR polynya edge. For the twelve winters of 1990-2001, the ice thicknesses and heat fluxes within the polynya are estimated from daily SSM/I data, then compared with field data and with estimates from other investigations. The results show the following: First, our calculated heat losses are consistent with 2 years of over-winter salinity and temperature field data. Second, comparison with other numerical and satellite estimates of the ice production shows that although our ice production per unit area is smaller, our polynya areas are larger, so that our ice production estimates are of the same order. Because our salinity forcing occurs over a larger area than in the other models, the oceanic response associated with our forcing will be modified. C1 Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Martin, S (reprint author), Univ Washington, Sch Oceanog, Box 357940, Seattle, WA 98195 USA. EM seelye@ocean.washington.edu RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 19 TC 69 Z9 71 U1 5 U2 13 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 OCT 26 PY 2004 VL 109 IS C10 AR C10012 DI 10.1029/2004JC002428 PG 15 WC Oceanography SC Oceanography GA 867ZZ UT WOS:000224882900003 ER PT J AU Jacqmin, D AF Jacqmin, D TI Onset of wetting failure in liquid-liquid systems SO JOURNAL OF FLUID MECHANICS LA English DT Article ID CONTACT-LINE; AIR ENTRAINMENT; INTERFACE; COATINGS; SURFACE; MODEL; SPEED AB Some model problems are considered in order to investigate wetting failure in liquid-liquid systems. Three geometries are considered, two-dimensional two-phase shear flow, two-dimensional driven capillary rise, and both two- and three-dimensional two-phase driven cavity flow. In the first two cases, the two fluids are made equiviscous. The driven cavity flow is investigated for both equi- and non-equiviscous fluids. Three methods of analysis are used for the equiviscous case, an essentially exact Fourier series method, a quasi-parallel approximation and a phase-field model. The Fourier series validates the phase-field method in that they both give nearly identical results for onset of instability. At relatively large slip length divided by channel width (10(-2)), the capillary number at which onset of wetting failure (entrainment of the receding fluid in the advancing) occurs is highly dependent on the type of flow. This dependence, however, appears to diminish rapidly as the slip length becomes smaller. The capillary number for the onset of instability is moderately dependent on gravity level. Three-dimensional phase-field calculations are then discussed that show wetting failure through tipstreaming and splitting instabilities. Spot checks indicate that the onset points of two- and three-dimensional instabilities are very close. It is hypothesized that tipstreaming can be understood in part as a quasi-two-dimensional phenomenon. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Jacqmin, D (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 20 TC 19 Z9 19 U1 0 U2 6 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 OCT 25 PY 2004 VL 517 BP 209 EP 228 DI 10.1017/S0022112004000643 PG 20 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 871YS UT WOS:000225173200010 ER PT J AU Whittenberger, JD Darolia, R AF Whittenberger, JD Darolia, R TI Slow plastic compressive behavior of NiAl-xCr single crystals at 1100-1500K SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE NiAl single crystals; solid solution strengthening; creep; elevated temperature; intermetallics ID SOLID-SOLUTION ALLOYS; ROD-PLATE TRANSITION; ELEVATED-TEMPERATURE; GRAIN-SIZE; MECHANICAL-PROPERTIES; FLOW PROPERTIES; CREEP-BEHAVIOR; DEFORMATION; COMPOSITES; CR AB The compressive properties of near (001) and (111)-oriented NiAl-2Cr single crystals and near (011)-oriented NiAl-6Cr samples have been measured between 1100 and 1500 K. The 2Cr addition produced significant solid solution strengthening in NiAl, and the (111) and (001) single crystals possessed similar strengths. The 6Cr crystals were not stronger than the 2Cr versions. At 1100 and 1200 K plastic flow in all three Cr-modified materials was highly dependent on stress with exponents > 10. The (011)-oriented 6Cr alloy exhibited a stress exponent of about 8 at 1400 K and 1500 K; whereas both (001) and (111) NiAl-2Cr crystals possessed stress exponents near three which is indicative of a viscous dislocation glide creep mechanism. While the Cottrell-Jaswon solute drag model predicted creep rates within a factor of three at 1500 K for (001)-oriented NiAl-2Cr; this mechanism greatly over predicted creep rates for other orientations and at 1400 K for (001) crystals. Published by elsevier B.V. C1 NASA, Glenn Res Ctr, Div Mat, N Olmsted, OH 44135 USA. GE Aircraft Engines, Cincinnati, OH 45215 USA. RP Whittenberger, JD (reprint author), NASA, Glenn Res Ctr, Div Mat, 4311 Porter Rd, N Olmsted, OH 44135 USA. EM msea_jdw@yahoo.com NR 42 TC 1 Z9 1 U1 1 U2 6 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 OCT 25 PY 2004 VL 384 IS 1-2 BP 361 EP 372 DI 10.1016/j.msea.2004.06.035 PG 12 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 862KK UT WOS:000224489300042 ER PT J AU Fujimoto, R Takei, Y Tamura, T Mitsuda, K Yamasaki, NY Shibata, R Ohashi, T Ota, N Audley, MD Kelley, RL Kilbourne, CA AF Fujimoto, R Takei, Y Tamura, T Mitsuda, K Yamasaki, NY Shibata, R Ohashi, T Ota, N Audley, MD Kelley, RL Kilbourne, CA TI Probing warm-hot intergalactic medium associated with the Virgo cluster using an oxygen absorption line SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN LA English DT Letter DE cosmology : large-scale structure of universe; cosmology : observations; galaxies : clusters : individual (Virgo); galaxies : intergalactic medium; galaxies : quasars : absorption lines ID X-RAY-ABSORPTION; XMM-NEWTON; CHANDRA DETECTION; ALPHA ABSORPTION; BARYON CONTENT; DISCOVERY; GALAXIES; FOREST; PARAMETERS; COSMOLOGY AB To detect a warm-hot intergalactic medium (WHIM) associated with the large-scale structure of the universe, we observed a quasar behind the Virgo cluster with XMM-Newton. With 54 ks exposure, we marginally detected an O VIII Kalpha absorption line at 650.9(-1.9)(+0.8) eV in the RGS spectra, with a statistical confidence of 96.4%. The observed line center energy is consistent with the redshift of M 87, and hence the absorber is associated with the Virgo cluster. From the curve of growth, the O VIII column density was estimated to be greater than or equal to 7 x 10(16) cm(-2). In the EPIC spectra, excess emission was found after evaluating the hot ICM in the Virgo cluster and various background components. We inspected the RASS map of the diffuse soft X-ray background, and confirmed that the level of the north and west regions just outside of the Virgo cluster is consistent with the background model that we used, while that of the east side is significantly higher and the enhancement is comparable with the excess emission found in the EPIC data. We consider a significant portion of the excess emission to be associated with the Virgo cluster, although a possible contribution from the North Polar Spur cannot be excluded. Using the column density and the emission measure and assuming an oxygen abundance of 0.1 and an ionization fraction of 0.4, we estimate that the mean electron density and the line-of-sight distance of the warm-hot gas are less than or equal to 6 x 10(-5) cm(-3) and greater than or equal to 9 Mpc. These strongly suggest detection of a WHIM in a filament associated with the Virgo cluster. C1 Japan Aerospace Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. Nagoya Univ, Dept Phys, Chikusa Ku, Nagoya, Aichi 4648602, Japan. Tokyo Metropolitan Univ, Dept Phys, Hachioji, Tokyo 1920397, Japan. Royal Observ, UK Astron Technol Ctr, Edinburgh EH9 3HJ, Midlothian, Scotland. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Japan Aerospace Explorat Agcy, Inst Space & Astronaut Sci, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 2298510, Japan. EM fujimoto@astro.isas.jaxa.jp RI Yamasaki, Noriko/C-2252-2008; Mitsuda, Kazuhisa/C-2649-2008; Kelley, Richard/K-4474-2012 NR 32 TC 17 Z9 17 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0004-6264 EI 2053-051X J9 PUBL ASTRON SOC JPN JI Publ. Astron. Soc. Jpn. PD OCT 25 PY 2004 VL 56 IS 5 BP L29 EP L34 DI 10.1093/pasj/56.5.L29 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 870FS UT WOS:000225043600002 ER PT J AU Emslie, AG Kucharek, H Dennis, BR Gopalswamy, N Holman, GD Share, GH Vourlidas, A Forbes, TG Gallagher, PT Mason, GM Metcalf, TR Mewaldt, RA Murphy, RJ Schwartz, RA Zurbuchen, TH AF Emslie, AG Kucharek, H Dennis, BR Gopalswamy, N Holman, GD Share, GH Vourlidas, A Forbes, TG Gallagher, PT Mason, GM Metcalf, TR Mewaldt, RA Murphy, RJ Schwartz, RA Zurbuchen, TH TI Energy partition in two solar flare/CME events SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE solar flares; coronal mass ejections; solar energetic particles; energetics; hard X rays; gamma rays ID ADVANCED COMPOSITION EXPLORER; CORONAL MASS EJECTIONS; X-RAY-SPECTRA; FORCE-FREE; MAGNETIC-FIELD; PARTICLE-ACCELERATION; ISOTOPE SPECTROMETER; RHESSI OBSERVATIONS; ELECTRON; BREMSSTRAHLUNG AB Using coordinated observations from instruments on the Advanced Composition Explorer (ACE), the Solar and Heliospheric Observatory (SOHO), and the Ramaty High Energy Solar Spectroscopic Imager (RHESSI), we have evaluated the energetics of two well-observed flare/CME events on 21 April 2002 and 23 July 2002. For each event, we have estimated the energy contents ( and the likely uncertainties) of ( 1) the coronal mass ejection, ( 2) the thermal plasma at the Sun, ( 3) the hard X-ray producing accelerated electrons, ( 4) the gamma-ray producing ions, and ( 5) the solar energetic particles. The results are assimilated and discussed relative to the probable amount of nonpotential magnetic energy available in a large active region. C1 Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Res Lab, Washington, DC 20375 USA. GSI, L 3 Commun, New York, NY USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Lockheed Martin Solar & Astrophys Lab, Dept L9 41, Palo Alto, CA 94304 USA. CALTECH, Downs Lab 220 47, Pasadena, CA 91125 USA. Sci Syst & Applicat Inc, Lanham, MD USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. RP Emslie, AG (reprint author), Oklahoma State Univ, Dept Phys, Stillwater, OK 74078 USA. EM gordon.emslie@okstate.edu; kucharek@atlas.sr.unh.edu; brian.r.dennis@nasa.gov; gopals@fugee.gsfc.nasa.gov; gordon.d.holman@nasa.gov; gerald.share@nrl.navy.mil; avourlid@pythia.nrl.navy.mil; terry.forbes@unh.edu; peter.t.gallagher.1@gsfc.nasa.gov; glenn.mason@umail.umd.edu; metcalf@lmsal.com; rmewaldt@srl.caltech.edu; murphy@nrl.navy.mil; richard.a.schwartz.1@gsfc.nasa.gov; thomasz@umich.edu RI Vourlidas, Angelos/C-8231-2009; Holman, Gordon/C-9548-2012; Dennis, Brian/C-9511-2012; Gopalswamy, Nat/D-3659-2012; Gallagher, Peter/C-7717-2011 OI Vourlidas, Angelos/0000-0002-8164-5948; Gallagher, Peter/0000-0001-9745-0400 NR 55 TC 145 Z9 146 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-SPACE JI J. Geophys. Res-Space Phys. PD OCT 23 PY 2004 VL 109 IS A10 AR A10104 DI 10.1029/2004JA010571 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 867YL UT WOS:000224878800004 ER PT J AU Johnson, M AF Johnson, M TI Networking for the earth sciences SO COMPUTER NETWORKS-THE INTERNATIONAL JOURNAL OF COMPUTER AND TELECOMMUNICATIONS NETWORKING LA English DT Editorial Material C1 NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. RP Johnson, M (reprint author), NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. EM mjj@riacs.edu NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1389-1286 J9 COMPUT NETW JI Comput. Netw. PD OCT 22 PY 2004 VL 46 IS 3 BP 295 EP 298 DI 10.1016/j.comnet.2004.07.011 PG 4 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 861HF UT WOS:000224406000001 ER PT J AU Loiacono, J Germain, A Smith, J AF Loiacono, J Germain, A Smith, J TI Network performance measurements for NASA's Earth Observation System SO COMPUTER NETWORKS-THE INTERNATIONAL JOURNAL OF COMPUTER AND TELECOMMUNICATIONS NETWORKING LA English DT Article DE network measurement; network performance; data distribution AB NASA's Earth Observation System (EOS) Project studies all aspects of planet Earth from space, including climate change, and ocean, ice, land, and vegetation characteristics. It consists of about 20 satellite missions over a period of about a decade. Extensive collaboration is used, both with other US agencies (e.g., National Oceanic and Atmospheric Administration, NOAA; United States Geological Survey, USGS; Department of Defense, DoD), and international agencies (e.g., European Space Agency, ESA; Japan Aerospace Exploration Agency, JAXA), to improve cost effectiveness and obtain otherwise unavailable data. Scientific researchers are located at research institutions worldwide, primarily government research facilities and research universities. The EOS project makes extensive use of networks to support data acquisition, data production, and data distribution. Many of these functions impose requirements on the networks, including throughput and availability. In order to verify that these requirements are being met, and be pro-active in recognizing problems, NASA conducts on-going performance measurements. The purpose of this paper is to examine techniques used by NASA to measure the performance of the networks used by EOSDIS (EOS Data and Information System) and to indicate how this performance information is used. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Swales Aerosp Inc, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Comp Sci Corp, Greenbelt, MD 20771 USA. RP Germain, A (reprint author), NASA, Goddard Space Flight Ctr, Swales Aerosp Inc, Greenbelt, MD 20771 USA. EM andyg@rattler-e.gsfc.nasa.gov NR 4 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1389-1286 J9 COMPUT NETW JI Comput. Netw. PD OCT 22 PY 2004 VL 46 IS 3 BP 299 EP 320 DI 10.1016/j.comnet.2004.06.017 PG 22 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 861HF UT WOS:000224406000002 ER PT J AU Johnson, M Freeman, K Gilstrap, R Beck, R AF Johnson, M Freeman, K Gilstrap, R Beck, R TI Networking technologies enable advances in Earth Science SO COMPUTER NETWORKS-THE INTERNATIONAL JOURNAL OF COMPUTER AND TELECOMMUNICATIONS NETWORKING LA English DT Article DE Earth Science application; field experiment; portable satellite dish; NREN AB This paper describes an experiment to prototype a new way of conducting science by applying networking and distributed computing technologies to an Earth Science application. A combination of satellite, wireless, and terrestrial networking provided geologists at a remote field site with interactive access to supercomputer facilities at two NASA centers, thus enabling them to validate and calibrate remotely sensed geological data in near real time. This represents a fundamental shift in the way that Earth scientists analyze remotely sensed data. In this paper we describe the experiment and the network infrastructure that enabled it, analyze the data flow during the experiment, and discuss the scientific impact of the results. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. Univ Cincinnati, Dept Geog, Cincinnati, OH 45221 USA. RP Johnson, M (reprint author), NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. EM mjj@riacs.edu NR 11 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1389-1286 J9 COMPUT NETW JI Comput. Netw. PD OCT 22 PY 2004 VL 46 IS 3 BP 423 EP 435 DI 10.1016/j.comnet.2004.06.015 PG 13 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 861HF UT WOS:000224406000009 ER PT J AU Jones, GH Brandt, JC AF Jones, GH Brandt, JC TI The interaction of comet 153P/Ikeya-Zhang with interplanetary coronal mass ejections: Identification of fast ICME signatures SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HELIOSPHERIC CURRENT SHEET; INTER-PLANETARY GAS; PLASMA-TAIL; SOLAR-WIND; DISCONNECTION EVENTS; LATITUDE VARIATIONS; RECONNECTION; DISTURBANCES; HALLEY AB The active comet 153P/Ikeya-Zhang possessed a highly-variable plasma tail. Favorable circumstances allowed the identification of the impact of fast ICMEs with the comet. The impact produces a specific morphology including a characteristic scalloped appearance which suggests that the ICME magnetic field drapes around preexisting tail density enhancements. This appears to be the first direct association between fast ICMEs and plasma tail structure and the specific structure should permit the identification of fast ICME locations in the heliosphere. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. RP Jones, GH (reprint author), CALTECH, Jet Prop Lab, Mail Stop 169-506,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM geraint.h.jones@jpl.nasa.gov; jcbrandt@unm.edu RI Jones, Geraint/C-1682-2008; OI Jones, Geraint/0000-0002-5859-1136 NR 30 TC 8 Z9 8 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 22 PY 2004 VL 31 IS 20 AR L20805 DI 10.1029/2004GL021166 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 867XL UT WOS:000224876000004 ER PT J AU Lee, SH Wilson, JC Baumgardner, D Herman, RL Weinstock, EM LaFleur, BG Kok, G Anderson, B Lawson, P Baker, B Strawa, A Pittman, JV Reeves, JM Bui, TP AF Lee, SH Wilson, JC Baumgardner, D Herman, RL Weinstock, EM LaFleur, BG Kok, G Anderson, B Lawson, P Baker, B Strawa, A Pittman, JV Reeves, JM Bui, TP TI New particle formation observed in the tropical/subtropical cirrus clouds SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE new particle formation; cirrus clouds; upper troposphere and lower stratosphere (UT-LS) ID CONDENSATION NUCLEI; UPPER TROPOSPHERE; LOWER STRATOSPHERE; BINARY NUCLEATION; MARINE ATMOSPHERE; RELATIVE-HUMIDITY; AEROSOL FORMATION; SULFURIC-ACID; NASA ER-2; AIRCRAFT AB Previous studies show that new particle formation takes place in the outflows of marine stratus and cumulus clouds. Here we show measurements of high concentrations of ultrafine particles, diameters (D-p) from 4 to 9 nm (N4-9), in interstitial cloud aerosol. These ultrafine particles indicate that in situ new particle formation occurs interstitially in cirrus clouds. Measurements were made at altitudes from 7 to 16 km over Florida with instruments on the WB-57F aircraft during Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiments (CRYSTAL-FACE) in July 2002. Size-resolved ice crystal particle concentrations and water vapor concentrations were measured to help identify the presence of cirrus clouds. About 72% of the in-cloud samples showed new particle formation events with the average N4-9 of 3.0 x 10(3) cm(-3), whereas about 56% of the out-of-cloud samples had events with the lower N4-9 of 1.3 x 10(3) cm(-3). The periods during which high N4-9 appeared were often associated with times of increasing ice water content (IWC) and high relative humidity with respect to ice (RHI); however, the measured N4-9 was not quantitatively correlated to IWC. The magnitude and frequency of new particle formation events seen in cirrus clouds were also higher than those previously observed in the tropical/subtropical upper troposphere in the absence of clouds. These results suggest that cirrus clouds may provide favorable conditions for particle formation, such as low temperatures, high RHI, high OH production ( due to high water vapor), cloud electricity, and atmospheric convection. At present, however, particle formation mechanisms in clouds are unidentified. C1 Univ Denver, Dept Engn, Denver, CO 80208 USA. Droplet Measurement Technol, Boulder, CO 80301 USA. Univ Nacl Autonoma Mexico, Ctr Ciencias Atmosfera, Mexico City 04510, DF, Mexico. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Harvard Univ, Cambridge, MA 02138 USA. NASA, Langley Res Ctr, Chem & Dynam Branch, Hampton, VA 23681 USA. SPEC Inc, Boulder, CO 80301 USA. NASA, Ames Res Ctr, Moffett Field, CA 94305 USA. RP Lee, SH (reprint author), Univ Denver, Dept Engn, 2390 S York St, Denver, CO 80208 USA. EM shanlee@du.edu RI Herman, Robert/H-9389-2012; Lee, Shan-Hu/F-9913-2014 OI Herman, Robert/0000-0001-7063-6424; NR 45 TC 28 Z9 29 U1 3 U2 8 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 22 PY 2004 VL 109 IS D20 AR D20209 DI 10.1029/2004JD005033 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 867XU UT WOS:000224877000007 ER PT J AU Beacom, JF Vagins, MR AF Beacom, JF Vagins, MR TI Antineutrino spectroscopy with large water Cerenkov detectors SO PHYSICAL REVIEW LETTERS LA English DT Article ID ATMOSPHERIC NEUTRINOS; SOLAR NEUTRINOS; SUPERNOVA; OSCILLATION; GADOLINIUM AB We propose modifying large water Cerenkov detectors by the addition of 0.2% gadolinium trichloride, which is highly soluble, newly inexpensive, and transparent in solution. Since Gd has an enormous cross section for radiative neutron capture, with SigmaE(gamma)=8 MeV, this would make neutrons visible for the first time in such detectors, allowing antineutrino tagging by the coincidence detection reaction (ν) over bar (e)+p-->e(+)+n (similarly for (ν) over bar (mu)). Taking Super-Kamiokande as a working example, dramatic consequences for reactor neutrino measurements, first observation of the diffuse supernova neutrino background, galactic supernova detection, and other topics are discussed. C1 Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 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 32 TC 173 Z9 173 U1 1 U2 3 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 22 PY 2004 VL 93 IS 17 AR 171101 DI 10.1103/PhysRevLett.93.171101 PG 4 WC Physics, Multidisciplinary SC Physics GA 864WC UT WOS:000224662700014 PM 15525063 ER PT J AU Stolc, V Gauhar, Z Mason, C Halasz, G van Batenburg, MF Rifkin, SA Hua, SJ Herreman, T Tongprasit, W Barbano, PE Bussemaker, HJ White, KP AF Stolc, V Gauhar, Z Mason, C Halasz, G van Batenburg, MF Rifkin, SA Hua, SJ Herreman, T Tongprasit, W Barbano, PE Bussemaker, HJ White, KP TI A gene expression map for the euchromatic genome of Drosophila melanogaster SO SCIENCE LA English DT Article ID TRANSCRIPTIONAL ACTIVITY; BITHORAX COMPLEX; OLIGONUCLEOTIDE MICROARRAYS; DNA; SEQUENCE; DOMAINS; ARRAYS; CELLS AB We used a maskless photolithography method to produce DNA oligonucleotide microarrays with unique probe sequences tiled throughout the genome of Drosophila melanogaster and across predicted splice junctions. RNA expression of protein coding and nonprotein coding sequences was determined for each major stage of the life cycle, including adult mates and females. We detected transcriptional activity for 93% of annotated genes and RNA expression for 41% of the probes in intronic and intergenic sequences. Comparison to genome-wide RNA interference data and to gene annotations revealed distinguishable levels of expression for different classes of genes and higher levels of expression for genes with essential cellular functions. Differential splicing was observed in about 40% of predicted genes, and 5440 previously unknown splice forms were detected. Genes within, conserved regions of synteny with D. pseudoobscura had highly correlated expression; these regions ranged in length from 10 to 900 kilobase pairs. The expressed intergenic and intronic sequences are more likely to be evolutionarily conserved than nonexpressed ones, and about 15% of them appear to be developmentally regulated. Our results provide a draft expression map for the entire nonrepetitive genome, which reveals a much more extensive and diverse set of expressed sequences than was previously predicted. C1 Yale Univ, Dept Genet, New Haven, CT 06520 USA. Yale Univ, Dept Mol Cellular & Dev Biol, New Haven, CT 06520 USA. Yale Univ, Dept Ecol & Evolutionary Biol, New Haven, CT 06520 USA. Yale Univ, Dept Math, New Haven, CT 06520 USA. NASA, Ames Res Ctr, Genome Res Facil, Moffett Field, CA 94035 USA. Eloret Corp, Sunnyvale, CA 94087 USA. Columbia Univ, Ctr Computat Biol & Bioinformat, New York, NY 10027 USA. Univ Amsterdam, Acad Med Ctr, Bioinformat Lab, NL-1100 DE Amsterdam, Netherlands. Columbia Univ, Dept Biol Sci, New York, NY 10027 USA. RP Yale Univ, Dept Genet, New Haven, CT 06520 USA. EM kevin.white@yale.edu OI Rifkin, Scott/0000-0001-8476-3256 FU NIGMS NIH HHS [T32GM008224-17]; NLM NIH HHS [P20LM007276-01] NR 32 TC 220 Z9 234 U1 3 U2 14 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD OCT 22 PY 2004 VL 306 IS 5696 BP 655 EP 660 DI 10.1126/science.1101312 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 866EN UT WOS:000224756700042 PM 15499012 ER PT J AU Gair, JR Barack, L Creighton, T Cutler, C Larson, SL Phinney, ES Vallisneri, M AF Gair, JR Barack, L Creighton, T Cutler, C Larson, SL Phinney, ES Vallisneri, M TI Event rate estimates for LISA extreme mass ratio capture sources SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 8th Gravitational Wave Data Analysis Workshop CY DEC 17-20, 2003 CL Milwaukee, WI ID BLACK-HOLE; GRAVITATIONAL-WAVES; GALAXY AB One of the most exciting prospects for the LISA gravitational wave observatory is the detection of gravitational radiation from the inspiral of a compact object into a supermassive black hole. The large inspiral parameter space and low amplitude of the signal make detection of these sources computationally challenging. We outline here a first-cut data analysis scheme that assumes realistic computational resources. In the context of this scheme, we estimate the signal-to-noise ratio that a source requires to pass our thresholds and be detected. Combining this with an estimate of the population of sources in the universe, we estimate the number of inspiral events that LISA could detect. The preliminary results are very encouraging-with the baseline design, LISA can see inspirals out to a redshift z = 1 and should detect over a thousand events during the mission lifetime. C1 CALTECH, LIGO Lab, Pasadena, CA 91125 USA. Univ Texas, Dept Phys & Astron, Brownsville, TX 78520 USA. Univ Texas, Ctr Gravitat Wave Astron, Brownsville, TX 78520 USA. Albert Einstein Inst, Max Planck Inst Gravitat Phys, D-14476 Golm, Germany. CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Gair, JR (reprint author), CALTECH, LIGO Lab, Pasadena, CA 91125 USA. EM jgair@tapir.caltech.edu RI Larson, Shane/E-8576-2010 NR 32 TC 96 Z9 96 U1 0 U2 1 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 OCT 21 PY 2004 VL 21 IS 20 SI SI BP S1595 EP S1606 AR PII S0264-9381(04)78810-3 DI 10.1088/0264-9381/21/20/003 PG 12 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 868QJ UT WOS:000224927800004 ER PT J AU Mohanty, SD Marka, S Rahkola, R Mukherjee, S Leonor, I Frey, R Cannizzo, J Camp, J AF Mohanty, SD Marka, S Rahkola, R Mukherjee, S Leonor, I Frey, R Cannizzo, J Camp, J TI Search algorithm for a gravitational wave signal in association with gamma ray burst GRB030329 using the LIGO detectors SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 8th Gravitational Wave Data Analysis Workshop CY DEC 17-20, 2003 CL Milwaukee, WI AB One of the brightest gamma ray bursts ever recorded, GRB030329, occurred during the second science run of the LIGO detectors. At that time, both interferometers at the Hanford, WA LIGO site were in lock and were acquiring data. The data collected from the two Hanford detectors were analysed for the presence of a gravitational wave signal associated with this GRB. This paper presents a detailed description of the search algorithm implemented in the current analysis. C1 Univ Texas, Brownsville, TX 78520 USA. Texas Southmost Coll, Brownsville, TX 78520 USA. CALTECH, LIGO, Pasadena, CA 91125 USA. Univ Oregon, Eugene, OR 97403 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Univ Texas, Brownsville, TX 78520 USA. RI Frey, Raymond/E-2830-2016 OI Frey, Raymond/0000-0003-0341-2636 NR 9 TC 12 Z9 12 U1 0 U2 1 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 OCT 21 PY 2004 VL 21 IS 20 SI SI BP S1831 EP S1837 AR PII S0264-9381(04)79347-8 DI 10.1088/0264-9381/21/20/026 PG 7 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 868QJ UT WOS:000224927800027 ER PT J AU Kozelov, BV Uritsky, VM Klimas, AJ AF Kozelov, BV Uritsky, VM Klimas, AJ TI Power law probability distributions of multiscale auroral dynamics from ground-based TV observations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SELF-ORGANIZED CRITICALITY; EARTHS PLASMA SHEET; INTERMITTENT TURBULENCE; MAGNETIC-FIELD; SPACE PLASMAS; COMPLEXITY; SUBSTORM AB Some of the most significant observational indications of self-organized critical (SOC) behavior in the magnetosphere are the scale-free statistical distributions of nighttime auroral emission regions as depicted by the Ultraviolet Imager (UVI) onboard the POLAR spacecraft [Uritsky et al., 2002]. Here, we report the results from a similar study of ground-based optical observations. Individual active auroral regions have been detected and analyzed using a spatiotemporal technique and statistical methods appropriate for quantifying critical behavior in SOC models. Probability distributions of the lifetime, maximum and integrated size, maximum power, and integrated energy output for auroral emission regions are shown to follow power law relations over wide ranges of scales. The powerlaw exponents that we obtained are consistent with the UVI image exponents, extending the range of observed scale-free auroral SOC dynamics by several orders of magnitude to smaller spatial and temporal scales. C1 Russian Acad Sci, Polar Geophys Inst, Apatity 184209, Murmansk Region, Russia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. St Petersburg State Univ, Inst Phys, St Petersburg 198504, Russia. RP Russian Acad Sci, Polar Geophys Inst, Apatity 184209, Murmansk Region, Russia. EM kozelov@pgi.kolasc.net.ru; uritsky@geo.phys.spbu.ru; alex.klimas@nasa.gov RI Kozelov, Boris/N-2731-2013 OI Kozelov, Boris/0000-0003-2738-2443 NR 19 TC 31 Z9 31 U1 0 U2 5 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 21 PY 2004 VL 31 IS 20 AR L20804 DI 10.1029/2004GL020962 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 867XJ UT WOS:000224875800004 ER EF