FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Golenetskii, S Aptekar, R Frederiks, D Mazets, E Palshin, V Hurley, K Cline, T Stern, B AF Golenetskii, S Aptekar, R Frederiks, D Mazets, E Palshin, V Hurley, K Cline, T Stern, B TI Observations of giant outbursts from Cygnus X-1 SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; gamma rays : observations; stars : individual (Cygnus X-1) ID RAY SPECTRAL VARIABILITY; X-RAY; BLACK-HOLES; ACCRETION DISCS; BINARY-SYSTEMS; HDE 226868; STATE; GEOMETRY; TRANSITIONS; STARS AB We present interplanetary network localization, spectral, and time history information for seven episodes of exceptionally intense gamma-ray emission from Cyg X-1. The outbursts occurred between 1995 and 2003, with durations up to similar to28,000 s. The observed 15-300 keV peak fluxes and fluences reached 3 x 10(-7) ergs cm(-2) s(-1) and 8 x 10(-4) ergs cm(-2), respectively. By combining the triangulations of these outbursts we derive an similar to1700 square arcminute (3 sigma) error ellipse that contains Cyg X-1 and no other known high-energy sources. The outbursts reported here occurred both when Cyg X-1 was in the hard state as well as in the soft one and at various orbital phases. The spectral data indicate that these outbursts display the same parameters as those of the underlying hard and soft states, suggesting that they represent another manifestation of these states. C1 AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Russian Acad Sci, Inst Nucl Res, Moscow 117312, Russia. RP Golenetskii, S (reprint author), AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. RI Frederiks, Dmitry/C-7612-2014; Pal'shin, Valentin/F-3973-2014; Aptekar, Raphail/B-3456-2015; Golenetskii, Sergey/B-3818-2015; OI Frederiks, Dmitry/0000-0002-1153-6340 NR 40 TC 21 Z9 21 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2003 VL 596 IS 2 BP 1113 EP 1120 DI 10.1086/378190 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 731ZH UT WOS:000185916000028 ER PT J AU Wilson, CA Patel, SK Kouveliotou, C Jonker, PG van der Klis, M Lewin, WHG Belloni, T Mendez, M AF Wilson, CA Patel, SK Kouveliotou, C Jonker, PG van der Klis, M Lewin, WHG Belloni, T Mendez, M TI Chandra observations of the faintest low-mass X-ray binaries SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; binaries : close; X-rays : binaries; X-rays : stars ID BULGE SOURCE SLX-1735-269; GALACTIC PLANE SURVEY; BURST SOURCES; NEUTRON-STAR; DISCOVERY; BEPPOSAX; SPECTRA; CATALOG AB A group of persistently faint Galactic X-ray sources exist that, based on their location in the Galaxy, high L-X=L-opt, association with X-ray bursts, and absence of low-frequency X-ray pulsations, are thought to be low-mass X-ray binaries (LMXBs). We present results from Chandra observations for eight of these systems: 4U 1708-408, 2S 1711-339, KS 1739-304, SLX 1735-269, GRS 1736-297, SLX 1746-331, 1E 1746.7-3224, and 4U 1812-12. Locations for all these sources, excluding GRS 1736-297, SLX 1746-331, and KS 1739-304 (which were not detected), were improved to 0."6 error circles (90% confidence). Our observations support earlier findings of transient behavior of GRS 1736-297, KS 1739-304, SLX 1746-331, and 2S 1711-339 (which we detect in one of two observations). Energy spectra for 4U 1708-408, 2S 1711-339, SLX 1735-269, 1E 1746.7-3224, and 4U 1812-12 are hard, with power-law indices typically 1.4-2.1, which is consistent with typical faint LMXB spectra. C1 Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Univ Amsterdam, Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands. MIT, Dept Phys, Cambridge, MA 02138 USA. MIT, Ctr Space Res, Cambridge, MA 02138 USA. Osserv Astron Brera, I-23807 Merate, LC, Italy. SRON, Natl Inst Space Res, NL-3584 CA Utrecht, Netherlands. Natl Space Sci & Technol Ctr, Space Sci Res Ctr SD 50, Huntsville, AL 35805 USA. RP Wilson, CA (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RI Mendez, Mariano/C-8011-2012 OI Mendez, Mariano/0000-0003-2187-2708 NR 40 TC 25 Z9 25 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2003 VL 596 IS 2 BP 1220 EP 1228 DI 10.1086/377473 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 731ZH UT WOS:000185916000036 ER PT J AU Rudy, RJ Dimpfl, WL Lynch, DK Mazuk, S Venturini, CC Wilson, JC Puetter, RC Perry, RB AF Rudy, RJ Dimpfl, WL Lynch, DK Mazuk, S Venturini, CC Wilson, JC Puetter, RC Perry, RB TI Near-infrared spectrophotometry and the CO emission in V2274 Cygni (Nova Cygni 2001 No. 1) SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : stars; novae, cataclysmic variables; stars : individual (V2274 Cygni) techniques : spectroscopic ID MU-M SPECTROSCOPY; CLASSICAL NOVAE; CARBON-MONOXIDE; VULPECULAE 1976; GALACTIC NOVAE; NQ VULPECULAE; SPECTRUM; LINES; SAGITTARII; PHOTOMETRY AB Infrared spectroscopy of V2274 Cygni (=Nova Cygni 2001 No. 1) is presented for two widely separated epochs, 17 and 370 days after discovery. In addition to the Paschen and Brackett series of H I, the early-time spectrum shows strong emission lines of C I and N I, fluorescently excited lines of O I, and emission from the first overtone of carbon monoxide. Because the initial data were probably acquired no more than 18 days after outburst, CO molecule formation occurred remarkably quickly in the dense, cool, carbon and oxygen rich ejecta. Rapid formation was also seen in NQ Vul, V842 Cen, and V705 Cas, three other novae in which first-overtone CO emission has been detected. Formation of the CO molecule may occur chemically in a process that requires H-2 as a precursor or directly through radiative association. The overtone emission of V2274 Cyg indicates a temperature of similar to2500 K. The vibrational levels show no obvious departures from thermal equilibrium, which may indicate high optical depths in the fundamental. A large C-13/C-12 ratio (0.83 +/- 0.3) is also indicated by the observations, consistent with the fast CNO burning expected in novae explosions. By the time of the second epoch observations, the emission lines of the neutral C, N, and O had disappeared. He I lambda10830 was the dominant emission feature in the spectrum. In addition to the hydrogen lines, recombination features of He II were also strong. The common nebular lines of [S III] were seen but only two coronal line, [S VIII] lambda9911 and [Si VI] lambda19645, were detected. The CO emission had disappeared, but a strong thermal dust component was present. The interstellar reddening for the system was found to be E(B-V) = 1.3. This extinction, together with the absolute magnitude derived from the rate of decline of the light curve, suggest a distance of similar to10.8 kpc. This places V2274 Cyg well out of the Galactic plane. The small number of novae with spectroscopic detections of carbon monoxide all have prominent C I lines, moderate speed classes and ejection velocities, exhibit marked dust formation events, and result from an explosion on a CO-type white dwarf. Based on these similarities, the spectrum of V2274 is proposed as a likely near-infrared spectral template for other novae that display carbon monoxide emission. C1 Aerosp Corp, Space Sci Applicat Lab, Los Angeles, CA 90009 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. Pixon LLC, San Diego, CA 92123 USA. NASA, Langley Res Ctr, Earth & Space Sci Support Off, Hampton, VA 23681 USA. RP Rudy, RJ (reprint author), Aerosp Corp, Space Sci Applicat Lab, POB 92957,M2-266, Los Angeles, CA 90009 USA. EM richard.j.rudy@aero.org; william.l.dimpfl@aero.org; david.k.lynch@aero.org; stephan.m.mazuk@aero.org; catherine.c.venturini@aero.org; jcw6z@virginia.edu; rpuetter@ucsd.edu; raleigh.b.perry@nasa.gov NR 52 TC 33 Z9 33 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2003 VL 596 IS 2 BP 1229 EP 1239 DI 10.1086/378083 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 731ZH UT WOS:000185916000037 ER PT J AU Haghighipour, N Couetdic, J Varadi, F Moore, WB AF Haghighipour, N Couetdic, J Varadi, F Moore, WB TI Stable 1 : 2 resonant periodic orbits in elliptic three-body systems SO ASTROPHYSICAL JOURNAL LA English DT Article DE celestial mechanics; minor planets, asteroids; planetary systems; solar system : general ID MEAN-MOTION RESONANCE; EXTRASOLAR PLANETS; RESTRICTED PROBLEM; LAGRANGIAN POINTS; STABILITY; ECCENTRICITY; GJ-876; CHAOS; PAIR AB The results of an extensive numerical study of the periodic orbits of planar, elliptic restricted three-body planetary systems consisting of a star, an inner massive planet, and an outer massless body in the external 1 : 2 mean-motion resonance are presented. Using the method of differential continuation, the locations of the resonant periodic orbits of such systems are identified, and through an extensive study of their phase-parameter space it is found that the majority of the resonant periodic orbits are unstable. For certain values of the mass and the orbital eccentricity of the inner planet, however, stable periodic orbits can be found. The applicability of such studies to the 1 : 2 resonance of the extrasolar planetary system GJ 876 is also discussed. C1 Northwestern Univ, Dearborn Observ, Evanston, IL 60208 USA. Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. Carnegie Inst Washington, NASA, Astrobiol Inst, Washington, DC 20015 USA. Ecole Cent Paris, F-92295 Chatenay Malabry, France. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, NASA, Astrobiol Inst, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. RP Haghighipour, N (reprint author), Northwestern Univ, Dearborn Observ, Evanston, IL 60208 USA. NR 34 TC 14 Z9 14 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2003 VL 596 IS 2 BP 1332 EP 1340 DI 10.1086/378119 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 731ZH UT WOS:000185916000045 ER PT J AU de Paz, AG Madore, BF Noeske, K Cairos, LM Papaderos, P Silich, SA AF de Paz, AG Madore, BF Noeske, K Cairos, LM Papaderos, P Silich, SA TI Discovery of a double ring in the dwarf galaxy Markarian 409 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : dwarf; galaxies : evolution; galaxies : individual (Markarian 409, NGC 3011); galaxies : kinematics and dynamics; galaxies : starburst ID STAR-FORMATION HISTORY; PROCESSED MATTER; MRK 86; MODELS; GAS AB We report the discovery of a double ring of emission-line regions around the nucleus of the blue compact dwarf galaxy Mrk 409 as seen by deep, ground-based Halpha images. Echelle spectroscopy obtained at Magellan I with MIKE shows the presence of ionized gas flowing out of the galaxy from a very massive (greater than or equal to7 x 10(6) M-.), nuclear starburst with projected expansion velocities of similar to 50 km s(-1). Different scenarios for the formation of these rings are discussed. While the innermost, nuclear ring is most probably formed by the interaction of a starburst-driven shock with the surrounding interstellar medium, the origin of the outer ring is less clear. C1 Carnegie Inst Washington, Carnegie Observ, Pasadena, CA 91101 USA. CALTECH, NASA IPAC Extragalact Database, Pasadena, CA 91125 USA. Univ Sternwarte Gottingen, D-37083 Gottingen, Germany. Inst Nacl Astrofis Opt & Elect, Tonantzintla 72000, Puebla, Mexico. RP de Paz, AG (reprint author), Carnegie Inst Washington, Carnegie Observ, 813 Santa Barbara St, Pasadena, CA 91101 USA. RI Papaderos, Polychronis/M-4206-2013; Gil de Paz, Armando/J-2874-2016 OI Papaderos, Polychronis/0000-0002-3733-8174; Gil de Paz, Armando/0000-0001-6150-2854 NR 20 TC 3 Z9 3 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2003 VL 596 IS 2 BP L179 EP L182 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 731ZJ UT WOS:000185916100014 ER PT J AU Gudipati, MS Allamandola, LJ AF Gudipati, MS Allamandola, LJ TI Facile generation and storage of polycyclic aromatic hydrocarbon ions in astrophysical ices SO ASTROPHYSICAL JOURNAL LA English DT Article DE astrochemistry; comets : general; dust, extinction; ISM : molecules; methods : laboratory; molecular processes ID SIDE-GROUP ADDITION; ULTRAVIOLET PHOTOLYSIS; INFRARED-SPECTROSCOPY; ABSORPTION FEATURES; INTERSTELLAR-MEDIUM; ORGANIC-MOLECULES; AMINO-ACIDS; XCN BAND; ANALOGS; IRRADIATION AB In situ ultraviolet-visible absorption and emission studies of vacuum ultraviolet (VUV) irradiated water-rich, cosmic ice analogs containing polycyclic aromatic hydrocarbons (PAHs) are described. VUV irradiation of 12 K water ices containing the PAHs naphthalene (H-2 O/C10H8 = 200) and 4-methylpyrene (H2O/C17H12 > 500) readily converts the PAHs into their cation form (PAH(+)). Under these conditions, PAH photoionization is the predominant reaction. These ions are trapped and stored in the ices at temperatures between 10 and 50 K, a temperature domain common to ices throughout interstellar clouds and the solar system. Unlike the similar to 15% ionization typical after VUV irradiation of PAHs isolated in rare-gas matrices, in water ice, PAH photoionization and storage proceed efficiently and almost quantitatively with a greater than 70% ionization yield. As the temperature is increased from 50 to 150 K, the PAH ion bands slowly diminish as the PAH ions ultimately react to form more complex organic species involving the water host. The chemical, spectroscopic, and physical properties of these ion-rich ices can be important in icy objects such as molecular clouds, comets, and planets. Several astrophysical applications are presented. 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, MS 245-6, Moffett Field, CA 94035 USA. RI Gudipati, Murthy/F-7575-2011 NR 38 TC 43 Z9 43 U1 3 U2 12 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2003 VL 596 IS 2 BP L195 EP L198 DI 10.1086/379595 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 731ZJ UT WOS:000185916100018 ER PT J AU Hollis, JM Pedelty, JA Boboltz, DA Liu, SY Snyder, LE Palmer, P Lovas, FJ Jewell, PR AF Hollis, JM Pedelty, JA Boboltz, DA Liu, SY Snyder, LE Palmer, P Lovas, FJ Jewell, PR TI Kinematics of the Sagittarius B2(N-LMH) molecular core SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : clouds; ISM : individual (Sagittarius B2(N-LMH)); ISM : molecules; radio lines : ISM ID STAR-FORMING REGION; CONTINUUM OBSERVATIONS; EMISSION; METHANOL; SCALE; B2; GLYCOLALDEHYDE AB Ethyl cyanide (CH3CH2CN) emission and absorption have been imaged with the Very Large Array toward Sagittarius B2(N-LMH) by means of the 5(15)-4(14) rotational transition at 43.5 GHz (lambda similar to mm). The 1."5 x 1."4 VLA beam shows two principal sources of ethyl cyanide emission: an unresolved source similar to5" north of the LMH that is kinematically consistent with simple expansion, contraction, or small-scale turbulence, and the resolved LMH core source itself that shows kinematics indicating an edge-on rotating disk that extends greater than or equal to3" (similar to0.1 pc) in the approximate east-west direction. A search for the 7(07) - 6(06) rotational transition of the amino acid glycine (NH2CH2COOH) at 43.7 GHz toward Sgr B2(N-LMH) gave negative results. C1 NASA, Goddard Space Flight Ctr, Earth & Space Data Comp Div, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. USN Observ, Washington, DC 20392 USA. Acad Sinica, Inst Astron & Astrophys, Taipei 106, Taiwan. Univ Illinois, Dept Astron, Urbana, IL 61801 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Natl Radio Astron Observ, Green Bank, WV 24944 USA. RP Hollis, JM (reprint author), NASA, Goddard Space Flight Ctr, Earth & Space Data Comp Div, Code 930, Greenbelt, MD 20771 USA. NR 18 TC 33 Z9 33 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2003 VL 596 IS 2 BP L235 EP L238 DI 10.1086/379315 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 731ZJ UT WOS:000185916100028 ER PT J AU Jenet, FA Gil, J AF Jenet, FA Gil, J TI Using the intensity modulation index to test pulsar radio emission models SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : general ID MILLISECOND PULSAR; EMPIRICAL-THEORY; DRIFTING SUBPULSES; SINGLE-PULSE; POLARIZATION; SCINTILLATIONS; RADIATION; B0943+10; B1937+21; TOPOLOGY AB This Letter explores the possibility of testing pulsar radio emission models by observing pulse-to-pulse intensity modulation. It is shown that a relationship between a pulsar's period, period derivative, and intensity modulation is a natural consequence of at least one theoretical model of radio pulsar emission. It is proposed that other models may also predict a similar correlation. The exact form of the relationship will depend on the model in question. Hence, observations of intensity modulation should be able to determine the validity of the various emission models. In an attempt to search for the predicted dependencies, the modulation properties of a set of 12 pulsars are studied. These data are suggestive, but they are unable to differentiate between three possibilities for the emission process. Future observations will be able to confirm these results and determine whether or not specific emission models are viable. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Zielona Gora, Inst Astron, PL-65265 Zielona Gora, Poland. RP Jenet, FA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 27 TC 7 Z9 7 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2003 VL 596 IS 2 BP L215 EP L218 DI 10.1086/379501 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 731ZJ UT WOS:000185916100023 ER PT J AU Lai, SP Velusamy, T Langer, WD AF Lai, SP Velusamy, T Langer, WD TI The high angular resolution measurement of ion and neutral spectra as a probe of the magnetic field structure in DR 21(OH) SO ASTROPHYSICAL JOURNAL LA English DT Article DE magnetic fields; stars : formation ID STAR-FORMING REGIONS; MOLECULAR CLOUDS AB It has been suggested that under average interstellar field strengths, the cyclotron interaction between ions and magnetic fields is strong enough to narrow the line width and suppress the line wings in the ion spectra. We present evidence of the cyclotron interaction effect at arcsec scales on the velocity dispersions in the spectra of ion/neutral molecular species in DR 21(OH) observed with the Owens Valley Radio Observatory Millimeter Array. Using a spatial resolution similar to 3 times higher than previous Caltech Submillimeter Observatory observations by Houde et al., we show that (HCO+)-C-13 and (HCN)-C-13 are coexistent at the scale of our observations (6"). In the eastern parts of the DR 21( OH) core where the dynamics is simple, the ion line widths are indeed narrower than the neutral line widths with an average ion-to-neutral line width ratio of 0.82 +/- 0.04. We use our results, along with the existing Zeeman and dust/CO polarization data on small scales, to derive the three-dimensional magnetic field structure. We obtain a field strength of 0.44 +/- 0.12 mG with an inclination of 36degrees to the line of sight, directed toward the observer, and a position angle of -75degrees in the plane of the sky. With the full magnetic field strength derived here, we are able to conclude that the MM1 core of DR 21( OH) is magnetically supercritical, although turbulence provides the dominant support. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Lai, SP (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NR 11 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 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2003 VL 596 IS 2 BP L239 EP L242 DI 10.1086/379502 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 731ZJ UT WOS:000185916100029 ER PT J AU Sui, LH Holman, GD AF Sui, LH Holman, GD TI Evidence for the formation of a large-scale current sheet in a solar flare SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : flares; Sun : X-rays, gamma rays ID EJECTION CURRENT SHEET; MAGNETIC RECONNECTION; RHESSI; MOTIONS; MODEL; PHASE; LOOPS AB We present X-ray evidence for the formation of a large-scale current sheet in a flare observed by the Ramaty High-Energy Solar Spectroscopic Imager on 2002 April 15. The flare occurred on the northwest limb, showing a cusp-shaped flare loop in the rise phase. When the impulsive rise in hard X-rays (>25 keV) began, the cusp part of the coronal source separated from the underlying flare loop and remained stationary for about 2 minutes. During this time, the underlying flare loops shrank at similar to 9 km s(-1). The temperature of the underlying loops increased toward higher altitudes, while the temperature of the coronal source increased toward lower altitudes. These results indicate that a current sheet formed between the top of the flare loops and the coronal source during the early impulsive phase. After the hard X-ray peak, the flare loops grew outward at similar to8 km s(-1), and the coronal source moved outward at similar to 300 km s(-1), indicating an upward expansion of the current sheet. About 30 minutes later, postflare loops seen in the Solar and Heliospheric Observatory (SOHO) EUV Imaging Telescope 195 Angstrom passband rose at similar to 10 km s(-1). A large coronal looplike structure, observed by the SOHO Large Angle and Spectrometric Coronagraph C2 and C3 detectors, also propagated outward at similar to 300 km s(-1). These observations are all consistent with the continued expansion of the current sheet. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Sui, LH (reprint author), Catholic Univ Amer, Dept Phys, 620 Michigan Ave, Washington, DC 20064 USA. RI Holman, Gordon/C-9548-2012 NR 29 TC 195 Z9 201 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2003 VL 596 IS 2 BP L251 EP L254 DI 10.1086/379343 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 731ZJ UT WOS:000185916100032 ER PT J AU Swain, M Vasisht, G Akeson, R Monnier, J Millan-Gabet, R Serabyn, E Creech-Eakman, M van Belle, G Beletic, J Beichman, C Boden, A Booth, A Colavita, M Gathright, J Hrynevych, M Koresko, C Le Mignant, D Ligon, R Mennesson, B Neyman, C Sargent, A Shao, M Thompson, R Unwin, S Wizinowich, P AF Swain, M Vasisht, G Akeson, R Monnier, J Millan-Gabet, R Serabyn, E Creech-Eakman, M van Belle, G Beletic, J Beichman, C Boden, A Booth, A Colavita, M Gathright, J Hrynevych, M Koresko, C Le Mignant, D Ligon, R Mennesson, B Neyman, C Sargent, A Shao, M Thompson, R Unwin, S Wizinowich, P TI Interferometer observations of subparsec-scale infrared emission in the nucleus of NGC 4151 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 4151); galaxies : Seyfert; instrumentation : interferometers ID ACTIVE GALACTIC NUCLEI; PALOMAR TESTBED INTERFEROMETER; NARROW-LINE REGION; NGC 4151; KECK INTERFEROMETER; ENERGY-DISTRIBUTIONS; SEYFERT-GALAXIES; RADIO JET; CONTINUUM; QUASARS AB We report novel, high angular resolution interferometric measurements that imply that the near-infrared nuclear emission in NGC 4151 is unexpectedly compact. We have observed the nucleus of NGC 4151 at 2.2 mum using the two 10 m Keck telescopes as an interferometer and find a marginally resolved source less than or equal to0.1 pc in diameter. Our measurements rule out models in which a majority of the K-band nuclear emission is produced on scales larger than this size. The interpretation of our measurement most consistent with other observations is that the emission mainly originates directly in the central accretion disk. This implies that active galactic nucleus unification models invoking hot, optically thick dust may not be applicable to NGC 4151. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Michelson Sci Ctr, Pasadena, CA 91125 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Calif Assoc Res Astron, WM Keck Observ, Kamuela, HI 96743 USA. RP Swain, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. OI Monnier, John D/0000-0002-3380-3307 NR 30 TC 54 Z9 54 U1 1 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 20 PY 2003 VL 596 IS 2 BP L163 EP L166 DI 10.1086/379235 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 731ZJ UT WOS:000185916100010 ER PT J AU Li, QB Jacob, DJ Yantosca, RM Heald, CL Singh, HB Koike, M Zhao, YJ Sachse, GW Streets, DG AF Li, QB Jacob, DJ Yantosca, RM Heald, CL Singh, HB Koike, M Zhao, YJ Sachse, GW Streets, DG TI A global three-dimensional model analysis of the atmospheric budgets of HCN and CH3CN: Constraints from aircraft and ground measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE biomass burning; pollution; nitriles; ocean uptake ID TRANSFORM INFRARED-SPECTROSCOPY; VERTICAL COLUMN ABUNDANCES; TRACE GAS MEASUREMENTS; MARINE BOUNDARY-LAYER; HYDROGEN-CYANIDE HCN; FREE TROPOSPHERIC CO; SEASONAL-VARIATIONS; PACIFIC-OCEAN; BIOGEOCHEMICAL CYCLES; NORTHERN JAPAN AB [1] We construct global atmospheric budgets of HCN and CH3CN through a three-dimensional (3-D) model simulation of the HCN-CH3CN-CO system constrained and evaluated with aircraft observations from the Transport and Chemical Evolution Over the Pacific (TRACE-P) mission over the NW Pacific in February - April 2001. Observed background vertical gradients of HCN and CH3CN imply a dominant ocean sink for both gases, with deposition velocity of 0.13 cm s(-1) for both and saturation ratios of 0.79 for HCN and 0.88 for CH3CN. Observations for both gases in the free troposphere imply a dominant source from biomass burning. Enhancement of HCN observed in Chinese urban plumes is attributed tentatively to residential coal burning. Biomass burning and residential coal burning emission ratios relative to CO of 0.27% and 1.6%, respectively, for HCN, and of 0.20% and 0.25%, respectively, for CH3CN, are consistent with observations in biomass burning and Chinese urban plumes. They provide the best model simulation of the ensemble of TRACE-P observations including vertical profiles and HCN- CH3CN- CO correlations. They also allow successful simulation of the long-term observations of HCN columns at sites in the Northern Hemisphere, and of the CH3CN vertical distribution observed over the northern Indian Ocean. Global biomass burning and Asian residential coal burning sources in the model are 0.63 and 0.2 Tg N yr(-1), respectively, for HCN and 0.47 and 0.03 Tg N yr(-1), respectively, for CH3CN. Ocean uptake is the dominant sink for both gases, with oxidation by OH representing an additional minor sink. The resulting tropospheric lifetimes are 5.3 months for HCN and 5.8 months for CH3CN. The model predicts very low HCN and CH3CN concentrations at high southern latitudes, reflecting the assumption of a uniform saturation ratio for ocean uptake; observations in that region are needed. In the free troposphere, the dominance of biomass burning sources ( 70 - 85% for HCN and 90 - 95% for CH3CN) implies that both gases can be used as biomass burning tracers. In the boundary layer, CH3CN appears to be a better biomass burning tracer. More work is needed to identify the origin of the Chinese urban source of HCN. C1 Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Harvard Univ, Div Engn & Appl Sci, Cambridge, MA 02138 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Tokyo, Dept Earth & Planetary Sci, Bunkyo Ku, Tokyo 1130033, Japan. Univ Calif Davis, Dept Mech & Aeronaut Engn, Davis, CA 95616 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Harvard Univ, Dept Earth & Planetary Sci, 20 Oxford St,Pierce Hall,Room 107F, Cambridge, MA 02138 USA. EM qli@io.harvard.edu; djj@io.harvard.edu; heald@fas.harvard.edu; hanwant.b.singh@nasa.gov; koike@eps.s.u-tokyo.ac.jp; yzhao@mae.ucdavis.edu; g.w.sachse@larc.nasa.gov; dstreets@anl.gov RI Heald, Colette/A-6813-2011; Koike, Makoto/F-4366-2011; Yantosca, Robert/F-7920-2014; Chem, GEOS/C-5595-2014 OI Yantosca, Robert/0000-0003-3781-1870; NR 58 TC 75 Z9 75 U1 0 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 18 PY 2003 VL 108 IS D21 AR 8827 DI 10.1029/2002JD003075 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 734ZW UT WOS:000186088700001 ER PT J AU Arvidson, RE Seelos, FP Deal, KS Koeppen, WC Snider, NO Kieniewicz, JM Hynek, BM Mellon, MT Garvin, JB AF Arvidson, RE Seelos, FP Deal, KS Koeppen, WC Snider, NO Kieniewicz, JM Hynek, BM Mellon, MT Garvin, JB TI Mantled and exhumed terrains in Terra Meridiani, Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Mars; Mars Exploration Rover Mission; Terra Meridiani ID THERMAL EMISSION SPECTROMETER; ORBITER LASER ALTIMETER; CAMERA; WATER; ROCKS; TES AB [1] Hematite-bearing deposits in the Terra Meridiani region of Mars constitute the top stratum of a partially eroded layered complex that covers dissected Noachian- aged cratered terrain. The hematite unit consists of dark plains and dunes covering a bright substrate. This substrate is fully exposed beyond the borders of the hematite-bearing deposit and consists of polygonal ground separated by ridges or valleys, together with layered deposits that have been eroded into a variety of landforms. The complex is partially covered by a regional-scale aeolian mantle that thickens toward the north. The hematite-bearing stratum exhibits low albedoes, pulse widths, and intermediate thermal inertias, whereas the underlying unit exhibits high values of these parameters. Both units have spectral emissivity signatures similar to those for the low albedo cratered terrain to the south, with the addition of hematite for the top stratum. The complex is interpreted to consist of extensive plains-forming lava flows and tephra deposits emplaced during an extensional regime and at least partially buried by an aeolian mantle. Aeolian stripping of the mantle exposed much of the complex and differentially eroded the deposits to produce the landforms existent today. Exploration of the hematite-bearing deposits by the 2003 Mars Exploration Rover, "Opportunity,'' will allow testing of the hypotheses presented since this stratum has been locally reworked into dunes that only partially cover the underlying brighter portion of the complex. In particular, the rover- based measurements will allow us to test the extent to which the unusual remote- sensing properties of the units indicate aqueous alteration. C1 Washington Univ, Dept Earth & Planetary Sci, McDonnell Ctr Space Sci, St Louis, MO 63130 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Arvidson, RE (reprint author), Washington Univ, Dept Earth & Planetary Sci, McDonnell Ctr Space Sci, Campus Box 1169,1 Brookings Dr, St Louis, MO 63130 USA. RI Mellon, Michael/C-3456-2016; Seelos, Frank/C-7875-2016 OI Seelos, Frank/0000-0001-9721-941X NR 23 TC 97 Z9 100 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD OCT 18 PY 2003 VL 108 IS E12 AR 8073 DI 10.1029/2002JE001982 PG 20 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 735AG UT WOS:000186089700001 ER PT J AU Simpson, IJ Wingenter, OW Westberg, DJ Fuelberg, HE Kiley, CM Crawford, JH Meinardi, S Blake, DR Rowland, FS AF Simpson, IJ Wingenter, OW Westberg, DJ Fuelberg, HE Kiley, CM Crawford, JH Meinardi, S Blake, DR Rowland, FS TI Airborne measurements of cirrus-activated C(2)Ckl(4) depletion in the upper troposphere with evidence against Cl reactions SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article DE tetrachloroethene; chlorine activation; heterogeneous chemistry; TRACE-P; cirrus ID VOLATILE ORGANIC-COMPOUNDS; HETEROGENEOUS CHEMISTRY; LOWERMOST STRATOSPHERE; CHLORINE ACTIVATION; TROPOPAUSE REGION; WATER-ICE; HCL; TETRACHLOROETHENE; CLOUDS; RANGE AB [1] Airborne whole air samples collected over the western Pacific in spring, 2001 showed depletion of tetrachloroethene (C2Cl4) in every upper tropospheric ( UT) air parcel that had interacted with large areas of cirrus less than three days upwind. The amount of C2Cl4 depletion showed a negative correlation with time since the interaction, consistent with the C2Cl4-depleted air parcels mixing with the ambient air as they moved downwind of the cirrus. Ethane and C2Cl4 both react relatively quickly with atomic chlorine (Cl) but ethane was not significantly depleted in these same air parcels, indicating that the C2Cl4 depletion cannot be attributed to Cl chemistry alone. Based on the minimum ethane depletion that can be detected by our measurements, a daytime upper limit of roughly 3 x 10(4) atom Cl cm(-3) is indirectly estimated for heterogeneous chlorine activation by cirrus clouds in the UT in tropical- and mid-latitudes during spring. C1 Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. New Mexico Inst Min & Technol, Dept Chem, Socorro, NM 87801 USA. Sci Applicat Int Corp, Hampton, VA 23681 USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. EM isimpson@uci.edu RI Crawford, James/L-6632-2013 OI Crawford, James/0000-0002-6982-0934 NR 22 TC 3 Z9 3 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 17 PY 2003 VL 30 IS 20 AR 2025 DI 10.1029/2003GL017598 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 734YZ UT WOS:000186086700001 ER PT J AU Antuna, JC Robock, A Stenchikov, G Zhou, J David, C Barnes, J Thomason, L AF Antuna, JC Robock, A Stenchikov, G Zhou, J David, C Barnes, J Thomason, L TI Spatial and temporal variability of the stratospheric aerosol cloud produced by the 1991 Mount Pinatubo eruption SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE volcano; lidar; satellite ID SAGE-II; EXTINCTION MEASUREMENTS; LIDAR MEASUREMENTS; SIZE DISTRIBUTION; VOLCANIC AEROSOL; MT-PINATUBO; VALIDATION; BACKSCATTER; SATELLITE; PROFILES AB [1] As a critical quality control step toward producing a stratospheric data assimilation system for volcanic aerosols, we conducted a comparison between Stratosphere Aerosol and Gas Experiment ( SAGE) II aerosol extinction profiles and aerosol backscatter measured by five lidars, both in the tropics and midlatitudes, for the two-year period following the 1991 Mt. Pinatubo eruption. The period we studied is the most challenging for the SAGE II retrieval because the aerosol cloud caused so much extinction of the solar signal that in the tropics few retrievals were possible in the core of the cloud. We compared extinction at two wavelengths at the same time that we tested two sets of conversions coefficients. We used both Thomason and Jager's extinction-to-backscatter conversion coefficients for converting lidar backscatter profiles at 0.532 mum or 0.694 mum wavelengths to the SAGE II extinction wavelengths of 0.525 mum and 1.020 mum or the nearby ones of 0.532 mum and 1.064 mum respectively. The lidars were located at Mauna Loa, Hawaii (19.5 degreesN, 155.6 degreesW), Camaguey, Cuba (21.4degreesN, 77.9degreesW), Hefei, China (31.9 degreesN, 117.2 degreesW), Hampton Virginia (37.1 degreesN, 76.3 degreesW), and Haute Provence, France (43.9 degreesN, 5.7 degreesW). For the six months following the eruption the aerosol cloud was much more heterogeneous than later. Using two alternative approaches, we evaluated the aerosol extinction variability of the tropical core of the Pinatubo stratospheric aerosol cloud at the timescale of 1 - 2 days, and found it was quite large. Aerosol variability played the major role in producing the observed differences between SAGE II and the lidars. There was in general a good agreement between SAGE II extinction measurements and lidar derived extinction, and we conclude that all five lidar sets we compared can be used in a future data assimilation of stratospheric aerosols. This is the most comprehensive comparison yet of lidar data with satellite data for the Pinatubo period. C1 Rutgers State Univ, Dept Environm Sci, New Brunswick, NJ 08901 USA. Acad Sinica, Anhui Inst Opt & Fine Mech, Hefei 230031, Anhui, Peoples R China. Univ Paris 06, Inst Pierre Simon Laplace, Observ Haute Provence, CNRS,Serv Aeron, F-75252 Paris 05, France. NOAA, Climate Monitoring & Diagnost Lab, Mauna Loa Observ, Hilo, HI 96721 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Antuna, JC (reprint author), Inst Meteorol, Estac Lidar Camaguey, Camaguey 70100, Cuba. EM anadelia@caonao.cmw.inf.cu; robock@envsci.rutgers.edu; gera@envsci.rutgers.edu; jzhou@aiofm.ac.cn; christine.david@aero.jussieu.fr; john.e.barnes@noaa.gov; l.w.thomason@nasa.gov RI Georgiy, Stenchikov/J-8569-2013; Robock, Alan/B-6385-2016 NR 32 TC 15 Z9 15 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 17 PY 2003 VL 108 IS D20 AR 4624 DI 10.1029/2003JD003722 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 734ZQ UT WOS:000186088200008 ER PT J AU Remsberg, E Lingenfelser, G Harvey, VL Grose, W Russell, J Mlynczak, M Gordley, L Marshall, BT AF Remsberg, E Lingenfelser, G Harvey, VL Grose, W Russell, J Mlynczak, M Gordley, L Marshall, BT TI On the verification of the quality of SABER temperature, geopotential height, and wind fields by comparison with Met Office assimilated analyses SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE temperature; geopotential height; satellite ID SUBTROPICAL MESOSPHERIC JET; LIMB INFRARED MONITOR; STRATOSPHERE; WINTER AB [1] The Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) experiment on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics satellite has delivered over 1 year of radiance profile data from which middle atmosphere temperature profiles have been retrieved. Version 1.01 temperatures are precise and sufficiently accurate, such that one can obtain estimates of their synoptic distributions on pressure surfaces. A sequential estimation algorithm was used to generate daily, zonal Fourier coefficients of temperature ( through zonal wave number 6), and maps on constant pressure surfaces were generated using those coefficients. Maps of temperature, geopotential height, and geostrophic winds are compared with products from the Met Office analyses. Stratospheric differences are within about 2 K for temperature and 160 m for geopotential height. The respective wind fields indicate flow patterns that are similar. Examples of the fields are shown for a period in February 2002 during a sudden stratospheric warming event that occurred in the Northern Hemisphere. A cooling of the middle mesosphere accompanies the warming. It is anticipated that large-scale, middle atmospheric dynamics and transport studies can be undertaken and that data assimilation products can be extended to near the mesopause using the SABER profiles. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. NASA, Sci Applicat Int Corp, LaRC, Hampton, VA 23681 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. GATS Inc, Newport News, VA 23606 USA. RP Remsberg, E (reprint author), NASA, Langley Res Ctr, Mail Stop 401B, Hampton, VA 23681 USA. EM e.e.remsberg@larc.nasa.gov; g.s.lingenfelser@larc.nasa.gov; v.l.harvey@larc.nasa.gov; w.l.grose@larc.nasa.gov; james.russell@hamptonu.edu; m.g.mlynczak@larc.nasa.gov; l.l.gordley@gats-inc.com; tom@gats-inc.com RI Mlynczak, Martin/K-3396-2012 NR 17 TC 68 Z9 69 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 OCT 17 PY 2003 VL 108 IS D20 AR 4628 DI 10.1029/2003JD003720 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 734ZQ UT WOS:000186088200007 ER PT J AU Zuidema, P Davies, R Moroney, C AF Zuidema, P Davies, R Moroney, C TI On the angular radiance closure of tropical cumulus congestus clouds observed by the Multiangle Imaging Spectroradiometer SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE 3-D radiative transfer; cumulus congestus; MISR ID INDEPENDENT PIXEL APPROXIMATION; SOLAR RADIATIVE-TRANSFER; BOUNDARY-LAYER CLOUDS; OPTICAL DEPTH; SATELLITE DATA; ZENITH ANGLE; REFLECTANCE; GEOMETRY; CONVECTION; DEPENDENCE AB [1] Monte Carlo reflectance simulations of three tropical cumulus congestus clouds reconstructed from Multiangle Imaging Spectroradiometer (MISR) data are compared to the domain-averaged MISR reflectance measurements. The goal of the comparison is to evaluate the nadir-view pixel cloud optical depth retrievals derived using plane-parallel radiative transfer theory, and the assumptions for vertically distributing the optical depth. Cloud heights are operationally retrieved using a stereo-imaging algorithm. The cloud heights and optical depths are at a 275 m spatial resolution, and for most simulations a vertical resolution of 250 m is applied. Five different but common three-dimensional cloud representations are assessed, using ( 1) a column vertical- mean volume extinction coefficient (b) value ( the reference case), ( 2) a volume extinction coefficient proportional to the two-thirds power of height ( the adiabatic assumption), ( 3) the adiabatic assumption at a 25 m vertical resolution, ( 4) a vertical- mean b retrieved from reflectances averaged over a (2.2 km)(2) area, and (5) a vertical-mean beta retrieved using off-nadir reflectances. An asymmetry about nadir in the observed reflectance means and skewnesses is not reproduced by any Monte Carlo simulation. The lack of symmetry can be related to differing proportions of unobscured sunlit and shadowed cloudy areas within the different views, even for these cases with viewing angles close to the perpendicular plane. The Monte Carlo simulations do not appear to capture the observed fraction of unobscured sunlit and shadowed cloudy areas, suggesting that radiatively significant cloud variability is occurring at scales smaller than the height field resolution of +/- 550 m. Results from the Monte Carlo simulation done at a higher vertical resolution are consistent with this. The cases examined also contain a nadir maximum in the observed reflectance skewnesses and a relative maximum for the observed nadir reflectances, attributed to the solar illumination of some optically thick cloud surfaces and to specular reflection pervading through the optically thin cloudy regions. This contrasts with previous modeling results that assume a Lambertian surface. C1 NOAA, Environm Technol Lab, Boulder, CO 80305 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Zuidema, P (reprint author), NOAA, Environm Technol Lab, ET6,325 Broadway, Boulder, CO 80305 USA. EM paquita.zuidema@noaa.gov RI Davies, Roger/D-4296-2009; Zuidema, Paquita/C-9659-2013 OI Davies, Roger/0000-0002-2991-0409; Zuidema, Paquita/0000-0003-4719-372X NR 50 TC 11 Z9 11 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD OCT 17 PY 2003 VL 108 IS D20 AR 4626 DI 10.1029/2003JD003401 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 734ZQ UT WOS:000186088200003 ER PT J AU Rignot, E Rivera, A Casassa, G AF Rignot, E Rivera, A Casassa, G TI Contribution of the Patagonia Icefields of South America to sea level rise SO SCIENCE LA English DT Article ID RECENT GLACIER VARIATIONS; NORTHERN PATAGONIA; INVENTORY; CHILE AB Digital elevation models of the Northern and Southern Patagonia Icefields of South America generated from the 2000 Shuttle Radar Topography Mission were compared with earlier cartography to estimate the volume change of the largest 63 glaciers. During the period 1968/1975-2000, these glaciers lost ice at a rate equivalent to a sea level rise of 0.042+/-0.002 millimeters per year. In the more recent years 1995-2000, average ice thinning rates have more than doubled to an equivalent sea level rise of 0.105+/-0.011 millimeters per year. The glaciers are thinning more quickly than can be explained by warmer air temperatures and decreased precipitation, and their contribution to sea level per unit area is larger than that of Alaska glaciers. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Chile, Dept Geog, Santiago, Chile. Univ Bristol, Sch Geog Sci, Bristol BS8 1SS, Avon, England. Ctr Estudios Cient, Valdivia, Chile. RP Rignot, E (reprint author), CALTECH, Jet Prop Lab, MS 300-227, Pasadena, CA 91109 USA. EM eric.rignot@jpl.nasa.gov; andres.rivera@bristol.ac.uk; gcasassa@cecs.cl RI Rignot, Eric/A-4560-2014; OI Rignot, Eric/0000-0002-3366-0481; Rivera, Andres/0000-0002-2779-4192 NR 28 TC 271 Z9 280 U1 2 U2 31 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD OCT 17 PY 2003 VL 302 IS 5644 BP 434 EP 437 DI 10.1126/science.1087393 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 732UD UT WOS:000185963200039 PM 14564005 ER PT J AU Hedges, SB AF Hedges, SB TI The coelacanth of frogs SO NATURE LA English DT Editorial Material ID OF-INDIA DISPERSAL; PHYLOGENY C1 Penn State Univ, NASA, Astrobiol Inst, University Pk, PA 16802 USA. Penn State Univ, Dept Biol, University Pk, PA 16802 USA. RP Hedges, SB (reprint author), Penn State Univ, NASA, Astrobiol Inst, University Pk, PA 16802 USA. NR 12 TC 21 Z9 24 U1 0 U2 3 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 16 PY 2003 VL 425 IS 6959 BP 669 EP 670 DI 10.1038/425669a PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 732DA UT WOS:000185924500021 PM 14562081 ER PT J AU Garces, JE Marino, AC Bozzolo, G AF Garces, JE Marino, AC Bozzolo, G TI Theoretical description of the interdiffusion of Al in the U-Mo solid solution SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT Conference on Applied Surface Modeling CY AUG 20-23, 2002 CL CLEVELAND, OHIO DE adatoms; alloys computer simulations; uranium; molybdenum; aluminum; semi-empirical methods and model calculations; single crystal surfaces; surface structure ID URANIUM; SURFACES; ALUMINUM; ALLOYS AB The Bozzolo-Ferrante-Smith (BFS) method for alloys was applied to the analysis of Al interdiffusion in the U-Mo solid solution system as a function of Mo concentration. The binary Al/U and Al/Mo systems show opposite behavior, which in the ternary case Al/U-Mo, translates into the role of regions rich in Mo acting as interdiffusion barriers to Al, in excellent agreement with experimental evidence. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. RP Bozzolo, G (reprint author), Ohio Aerosp Inst, 22800 Cedar Point Rd, Cleveland, OH 44142 USA. NR 12 TC 6 Z9 6 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD OCT 15 PY 2003 VL 219 IS 1-2 BP 47 EP 55 DI 10.1016/S0169-4332(03)00631-7 PG 9 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 726CJ UT WOS:000185580300006 ER PT J AU Farias, D Nino, MA de Miguel, JJ Miranda, R Morse, J Bozzolo, G AF Farias, D Nino, MA de Miguel, JJ Miranda, R Morse, J Bozzolo, G TI Growth of Co and Fe on Cu(111): experiment and BFS based calculations SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT Conference on Applied Surface Modeling CY AUG 20-23, 2002 CL CLEVELAND, OH DE thermal energy atom scattering; LEED; Monte Carlo simulations ID FILMS AB The structure and morphology of Co and Fe films grown on Cu(I 1 1) have been investigated by thermal energy atom scattering (TEAS) and low-energy electron diffraction (LEED). It has been found that the growth mode of Co and Fe can be greatly improved by using Pb as surfactant, although in the case of Fe this works only for the first bilayer. This shows that the two systems exhibit decisive differences already in the first stages of the growth process. In a second series of experiments, the effect of codepositing Co-Cu and Fe-Cu on the films quality was investigated. The results are very promising, and suggest that very flat, structurally ordered fcc Fe-Cu and Co-Cu films can be prepared by applying this technique together with the use of Pb as surfactant. These results were complemented by atomistic simulations based on the BFS method for alloys. Simulations performed in the low-coverage regime suggest that the early stages of growth are governed to a great extent by the affinity of Cu for Co and Fe. We have also performed temperature-dependent Monte Carlo simulations to determine the structure of superlattices formed by codeposition of Cu-Co and Cu-Fe. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Autonoma Madrid, Inst Nicolas Cabrera, Dept Fis Mat Condensada C 3, E-28049 Madrid, Spain. Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Univ Autonoma Madrid, Inst Nicolas Cabrera, Dept Fis Mat Condensada C 3, E-28049 Madrid, Spain. EM daniel.farias@uam.es RI de Miguel, Juan J./A-5183-2008; Farias, Daniel/L-2435-2013; Nino Orti, Miguel Angel/M-2571-2014 OI de Miguel, Juan J./0000-0003-0122-7605; Farias, Daniel/0000-0002-8537-8074; Nino Orti, Miguel Angel/0000-0003-3692-147X NR 11 TC 2 Z9 2 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 EI 1873-5584 J9 APPL SURF SCI JI Appl. Surf. Sci. PD OCT 15 PY 2003 VL 219 IS 1-2 BP 80 EP 87 DI 10.1016/S0169-4332(03)00635-4 PG 8 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 726CJ UT WOS:000185580300010 ER PT J AU Bozzolo, G Noebe, RD Khalil, J Morse, J AF Bozzolo, G Noebe, RD Khalil, J Morse, J TI Atomistic analysis of surface segregation in Ni-Pd alloys SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT Conference on Applied Surface Modeling CY AUG 20-23, 2002 CL CLEVELAND, OHIO DE surface segregation; atomistic modeling; Ni-Pd alloys ID REACTIVITY; METAL AB Atomistic analysis and large-scale atomistic simulations using the Bozzolo-Ferrante-Smith (BFS) method for alloys were performed to investigate surface segregation in Ni-Pd alloys as a function of temperature, crystal face, and composition. Pd-enrichment of the first layer was observed in (I 1 1) and (10 0) surfaces, and enrichment of the top two layers occurred for (I 10) surfaces. In all cases, the segregation profile shows alternating planes enriched and depleted in Pd in a decreasing oscillatory profile. Based on atom-by-atom static energy calculations, an explanation for the observed surface features is presented in terms of competing chemical and strain energy effects. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Bozzolo, G (reprint author), Ohio Aerosp Inst, 22800 Cedar Point Rd, Cleveland, OH 44142 USA. NR 16 TC 21 Z9 23 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD OCT 15 PY 2003 VL 219 IS 1-2 BP 149 EP 157 DI 10.1016/S0169-4332(03)00591-9 PG 9 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 726CJ UT WOS:000185580300020 ER PT J AU Vassiliadis, D Klimas, AJ Weigel, RS Baker, DN Rigler, EJ Kanekal, SG Nagai, T Fung, SF Friedel, RWH Cayton, TE AF Vassiliadis, D Klimas, AJ Weigel, RS Baker, DN Rigler, EJ Kanekal, SG Nagai, T Fung, SF Friedel, RWH Cayton, TE TI Structure of Earth's outer radiation belt inferred from long-term electron flux dynamics SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND; RELATIVISTIC ELECTRONS; MAGNETOSPHERE; ACCELERATION; SAMPEX; ZONE AB [1] We map the spatial structure of the electron belts over their radial range (L = 1 - 11 R-E) using a total of 25 years of observations by NASA, ISAS, and GPS spacecraft. Correlation analysis reveals significant radial structuring of the outer belt and identifies three regions, while earlier single-spacecraft studies are used to interpret the results. The central region P-1 ( L = 4.1 - 7.5 R-E) has a well-known slow response ( 2 - 3 days) most probably due to shear-hydrodynamic effects of the interplanetary medium, which excite ULF waves at low latitudes. In the innermost region P-0 (L = 3.0 - 4.1 R-E) the electron response is rapid (<1 day). It appears related to solar wind ram-hydrodynamic inputs (compressions) and/or time-varying interplanetary electric and magnetic fields. Region P-2 (L > 7.5 R-E) has a much weaker brief response to magnetic field orientation and low interplanetary plasma velocities, anticorrelated with the other two regions. The findings and, in addition, the solar-cycle modulation of the region size strongly suggest that the solar wind excites nonlinear response modes in the inner magnetosphere which are prototypically revealed in the three regions. Given this spatial variability, the optimal approach to next-generation modeling and electron storm forecasting may differ considerably for each region. C1 NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. Univ Colorado, Lab Astrophys & Space Phys, Boulder, CO 80309 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Tokyo Inst Technol, Tokyo 152, Japan. Los Alamos Natl Lab, NIS Div 2, Los Alamos, NM USA. RP Vassiliadis, D (reprint author), NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. RI Fung, Shing/F-5647-2012; Friedel, Reiner/D-1410-2012 OI Friedel, Reiner/0000-0002-5228-0281 NR 17 TC 17 Z9 17 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD OCT 15 PY 2003 VL 30 IS 19 AR 2015 DI 10.1029/2003gl017328 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 734YT UT WOS:000186086100001 ER PT J AU Rivas, C Lake, R Frensley, WR Klimeck, G Thompson, PE Hobart, KD Rommel, SL Berger, PR AF Rivas, C Lake, R Frensley, WR Klimeck, G Thompson, PE Hobart, KD Rommel, SL Berger, PR TI Full band modeling of the excess current in a delta-doped silicon tunnel diode SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; CURRENT-VOLTAGE CHARACTERISTICS; RESONANT INTERBAND; ESAKI JUNCTIONS; SI; TEMPERATURE; SEMICONDUCTORS; PARAMETERS; TRANSPORT; DEVICES AB The current of a molecular beam epitaxially grown Sb and B delta-doped Si tunnel diode is simulated in all regions of tunneling: peak, valley, and post-valley turn-on. All three regions of the I-V are qualitatively captured by the calculations. The inclusion in the model of bandtail states gives rise to the excess current and the post-valley turn on of the tunnel current. This excess current is dominated by the direct coherent tunneling component of the current tunneling from gap state to gap state. The crossover between phonon-assisted and direct occurs immediately after the valley minimum. The calculated voltages quantitatively match the experimental measurements. The magnitude of the calculated current is approximately a factor of 5.4 too small. Sources of error are analyzed. The current calculations use a second neighbor sp(3)s(*) planar orbital basis within the nonequilibrium Green function formalism. (C) 2003 American Institute of Physics. C1 Univ Calif Riverside, Dept Elect Engn, Riverside, CA 92521 USA. Univ Texas, Erik Jonsson Sch Engn, Richardson, TX 75083 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. USN, Res Lab, Washington, DC 20375 USA. Rochester Inst Technol, Microelect Engn Dept, Rochester, NY 14263 USA. Ohio State Univ, Dept Elect Engn, Columbus, OH 43210 USA. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. RP Rivas, C (reprint author), Univ Calif Riverside, Dept Elect Engn, Riverside, CA 92521 USA. RI Rommel, Sean/F-9654-2013; Berger, Paul/I-4063-2014; Klimeck, Gerhard/A-1414-2012 OI Rommel, Sean/0000-0001-5996-0813; Berger, Paul/0000-0002-2656-2349; Klimeck, Gerhard/0000-0001-7128-773X NR 41 TC 31 Z9 32 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD OCT 15 PY 2003 VL 94 IS 8 BP 5005 EP 5013 DI 10.1063/1.1606114 PG 9 WC Physics, Applied SC Physics GA 727NE UT WOS:000185664300044 ER PT J AU Perigaud, C McCreary, JP Zhang, KQ AF Perigaud, C McCreary, JP Zhang, KQ TI Impact of interannual rainfall anomalies on Indian Ocean salinity and temperature variability SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article DE rainfall; salinity; coupled Indian ocean-atmosphere ID WESTERN EQUATORIAL PACIFIC; SEA-SURFACE TEMPERATURE; MIXED-LAYER; ARABIAN SEA; DYNAMICS; CIRCULATION; MONSOON; MODEL; THERMODYNAMICS; ATMOSPHERE AB [1] A nonlinear reduced gravity model with four active layers and mixed layer physics is used to investigate how precipitation anomalies affect salinity and temperature variability in the Indian Ocean. In one experiment the model is forced by observations of monthly varying winds and rainfall for the period 1980 - 2000. In another it is forced by the same winds and climatological rainfall. Comparison between the two experiments is focused on the 1992 - 2000 period, during which rainfall variations attain extrema in the southeastern Indian Ocean with two deficits close to zero in 1994 and 1997 and a maximum of 16 mm/d in 1998. Rainfall anomalies significantly affect model sea surface salinity (SSS), but SSS is also highly governed by winds. Indeed, SSS is at its absolute minimum in 1994 despite the local rainfall deficit. Sea surface temperature (SST) is strongly affected along the equator east of 80 degreesE and along Indonesia where the mixed and the barrier layers become thin in 1994 and 1997. There the precipitation deficits affect SST primarily by entraining more subsurface water to the surface. In 1994 the subsurface waters are anomalously cool because of eastward advection of colder water from the west. In 1997 they are so because of northward advection of water cooled by coastal upwelling farther south. The precipitation excess does not affect SST because the temperature difference between the mixed layer and the barrier layer is very little then. Including interannual rainfall anomalies makes SST off Sumatra colder in 1994 and 1997, in much better agreement with observations. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Hawaii Manoa, Int Pacific Res Ctr, Honolulu, HI 96822 USA. RP Perigaud, C (reprint author), CALTECH, Jet Prop Lab, MS 300-323,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 44 TC 20 Z9 20 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-OCEANS JI J. Geophys. Res.-Oceans PD OCT 15 PY 2003 VL 108 IS C10 AR 3319 DI 10.1029/2002JC001699 PG 14 WC Oceanography SC Oceanography GA 734ZX UT WOS:000186088800001 ER PT J AU Jadaan, OM Nemeth, NN Bagdahn, J Sharpe, WN AF Jadaan, OM Nemeth, NN Bagdahn, J Sharpe, WN TI Probabilistic Weibull behavior and mechanical properties of MEMS brittle materials SO JOURNAL OF MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Winter Annual Meeting of the American-Society-of-Mechanical-Engineers CY NOV 11-16, 2001 CL NEW YORK, NEW YORK SP Amer Soc Mech Engineers ID SINGLE-CRYSTAL SILICON; THIN-FILMS; FRACTURE STRENGTH; YOUNGS MODULUS; TENSILE-STRENGTH; MICROCANTILEVER BEAMS; POLYSILICON FILMS; LOAD-DEFLECTION; SPECIMEN SIZE; BULGE TEST AB The objective of this work is to present a brief overview of a probabilistic design methodology for brittle structures, review the literature for evidence of probabilistic behavior in the mechanical properties of MEMS (especially strength), and to investigate whether evidence exists that a probabilistic Weibull effect exists at the structural microscale. Since many MEMS devices are fabricated from brittle materials, that raises the question whether these miniature structures behave similar to bulk ceramics. For bulk ceramics, the term Weibull effect is used to indicate that significant scatter in fracture strength exists, hence requiring probabilistic rather than deterministic treatment. In addition, the material's strength behavior can be described in terms of the Weakest Link Theory (WLT) leading to strength dependence on the component's size (average strength decreases as size increases), and geometry/loading configuration (stress distribution). Test methods used to assess the mechanical properties of MEMS, especially strength, are reviewed. Four materials commonly used to fabricate MEMS devices are reviewed in this report. These materials are polysilicon, single crystal silicon (SCS), silicon nitride, and silicon carbide. (C) 2003 Kluwer Academic Publishers. C1 Univ Wisconsin, Coll Engn Math & Sci, Platteville, WI 53818 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Fraunhofer Inst Mech Mat, Freiberg, Germany. Johns Hopkins Univ, Dept Mech Engn, Baltimore, MD 21218 USA. RP Jadaan, OM (reprint author), Univ Wisconsin, Coll Engn Math & Sci, Platteville, WI 53818 USA. OI Bagdahn, Joerg/0000-0002-1600-2444 NR 116 TC 70 Z9 71 U1 1 U2 18 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD OCT 15 PY 2003 VL 38 IS 20 BP 4087 EP 4113 DI 10.1023/A:1026317303377 PG 27 WC Materials Science, Multidisciplinary SC Materials Science GA 738CX UT WOS:000186270100004 ER PT J AU Elmustafa, AA Stone, DS AF Elmustafa, AA Stone, DS TI Stacking fault energy and dynamic recovery: do they impact the indentation size effect? SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE indentation size effect; geometrically necessary dislocations; stacking fault energy; work hardening; bi-linear behavior; nanoindentation ID STRAIN GRADIENT PLASTICITY; SINGLE-CRYSTALS; THIN-FILMS; HARDNESS; DEFORMATION; MOLYBDENUM; MODULUS; METALS; TESTS AB Aluminum, a high stacking fault energy (SFE) material and a-brass, a low SFE material were tested for the indentation size effect (ISE) using a combination of microhardness (high load) and nanoindentation (low load). Four samples from each material were tested; annealed electropolished, annealed mechanically polished, work-hardened electropolished, and work-hardened mechanically polished. The micro and nano indentations were made using a Vickers and a Berkovitch diamond indenter tips with indentation loads between 0.1-3 (microindentations) and 10(-4)-10(-2) N (nanoindentations), respectively. Based on areas measured using optical and scanning electron microscopy in addition to contact stiffness, it is found that the calculated nanohardness increases monotonically with decreasing load or depth of indentation. The work-hardened samples are harder than the annealed ones except for aluminum at shallow indents where it is not possible to distinguish between differences in hardness. All eight samples regardless of the SFE, rate and intensity of cross-slip and dislocation climbing rates (dynamic recovery), and level of prior work hardening of the material, explicitly exhibited an ISE. The magnitude of the ISE is not influenced by SFE, dynamic recovery, or prior level of work hardening. The data are found to behave linearly consistent with the Strain Gradient Plasticity model (SGP) for micro and deep nanoindentations; the shallow nanoindentation data deviated into a second linear behavior constituting what we term a 'bilinear behavior'. (C) 2003 Elsevier B.V. All rights reserved. C1 NASA, Langley Res Ctr, ConITS, Hampton, VA 23681 USA. Univ Wisconsin, Madison, WI 53706 USA. RP NASA, Langley Res Ctr, ConITS, Mail Stop 238,4 Langley Blvd,Bldg 1230, Hampton, VA 23681 USA. EM a.a.elmustafa@larc.nasa.gov RI Stone, Donald/A-7496-2016 NR 35 TC 9 Z9 9 U1 0 U2 13 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD OCT 15 PY 2003 VL 358 IS 1-2 BP 1 EP 8 DI 10.1016/S0921-5093(03)00293-4 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 713FE UT WOS:000184845800001 ER PT J AU Smits, J Wincheski, B Namkung, M Crooks, R Louie, R AF Smits, J Wincheski, B Namkung, M Crooks, R Louie, R TI Response of Fe powder, purified and as-produced HiPco single-walled carbon nanotubes to flash exposure SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Letter DE Fe powder; HiPco; carbon nanotubes AB The exposure of as-produced HiPCo single-walled carbon nanotubes (SWNTs) to a camera flash causes ignition, (oxidation) and subsequent coalescence of the Fe catalyst particles, while purified SWNTs do not respond to flashing. TEM and electron energy loss spectroscopy (EELS) analysis attribute the phenomena to the pyrophoric oxidation of Fe nanoparticles. (C) 2003 Elsevier Science B.V. All rights reserved. C1 NASA, Langley Res Ctr, Lockheed Martin Space Operat, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Pacific Lutheran Univ, Tacoma, WA 98447 USA. RP Smits, J (reprint author), NASA, Langley Res Ctr, Lockheed Martin Space Operat, Bldg 1230B,MS 231, Hampton, VA 23681 USA. RI Namkung, Min/E-1533-2012 NR 7 TC 26 Z9 26 U1 1 U2 4 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 15 PY 2003 VL 358 IS 1-2 BP 384 EP 389 DI 10.1016/S0921-5093(03)0282-X PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 713FE UT WOS:000184845800049 ER PT J AU Li, YY Roberts, WL Brown, MS Herring, GC AF Li, YY Roberts, WL Brown, MS Herring, GC TI Transient grating spectroscopy with delayed thermalization in non-combusting CO/air mixtures SO OPTICS COMMUNICATIONS LA English DT Article DE transient grating spectroscopy; TGS; active oxygen; singlet O-2((1)Delta(g)) ID LASER-INDUCED GRATINGS; STATE AB Transient grating spectroscopy is used to observe slowly forming thermal gratings in a mixture (non-combusting CO/air at less than or equal to 0.7 MPa) of two gases that are individually transparent. Thermalization in the mixture implies a photochemical process at 532 nm that populates the metastable singlet level (1)Delta(g) in O-2 through collision-assisted absorption in O-2 pairs. The laser intensity dependence of this process is measured. (C) 2003 Elsevier B.V. All rights reserved. C1 N Carolina State Univ, Raleigh, NC 27695 USA. Innovat Sci Solut Inc, Dayton, OH 45440 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Roberts, WL (reprint author), N Carolina State Univ, Raleigh, NC 27695 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD OCT 15 PY 2003 VL 226 IS 1-6 BP 255 EP 258 DI 10.1016/j.optcom.2003.08.036 PG 4 WC Optics SC Optics GA 738QE UT WOS:000186298700031 ER PT J AU Kolokolov, KI Li, J Ning, CZ AF Kolokolov, KI Li, J Ning, CZ TI k center dot p Hamiltonian without spurious-state solutions SO PHYSICAL REVIEW B LA English DT Article AB We developed a method to eliminate the spurious solutions of the k.p Hamiltonian by introducing an off-diagonal k(2) term. This results in a modification in the fourth- and higher-order terms in k of the band dispersion and does not affect the effective masses near the Gamma point. We show that such a modification leads to a monotonic behavior of the conduction band as a function of k and thus eliminate the spurious solutions in the calculations of confined states for all popular III-V compounds. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Kolokolov, KI (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Mail Stop N229-1, Moffett Field, CA 94035 USA. RI Ning, C. Z./D-4699-2009 OI Ning, C. Z./0000-0003-4583-8889 NR 9 TC 25 Z9 25 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD OCT 15 PY 2003 VL 68 IS 16 AR 161308 DI 10.1103/PhysRevB.68.161308 PG 4 WC Physics, Condensed Matter SC Physics GA 743KW UT WOS:000186571800011 ER PT J AU Kok, P Yurtsever, U AF Kok, P Yurtsever, U TI Gravitational decoherence SO PHYSICAL REVIEW D LA English DT Article ID WAVES AB We investigate the effect of quantum metric fluctuations on qubits that are gravitationally coupled to a background spacetime. In our first example, we study the propagation of a qubit in flat spacetime whose metric is subject to flat quantum fluctuations with a Gaussian spectrum. We find that these fluctuations cause two changes in the state of the qubit: they lead to a phase drift, as well as the expected exponential suppression (decoherence) of the off-diagonal terms in the density matrix. Although in principle observable, the current state of technology prohibits the experimental demonstration of the phase drift. Second, we calculate the decoherence of a qubit in a circular orbit around a Schwarzschild black hole. The no-hair theorems suggest a quantum state for the metric in which the black hole's mass fluctuates with a thermal spectrum at the Hawking temperature. Again, we find that the orbiting qubit undergoes decoherence and a phase drift that both depend on the temperature of the black hole. Third, we study the interaction of coherent and squeezed gravitational waves with a qubit in uniform motion. Finally, we investigate the decoherence of an accelerating qubit in Minkowski spacetime due to the Unruh effect. In this case decoherence is not due to fluctuations in the metric, but instead is caused by coupling (which we model with a standard Hamiltonian) between the qubit and the thermal cloud of Unruh particles bathing it. When the accelerating qubit is entangled with a stationary partner, the decoherence should induce a corresponding loss in teleportation fidelity. C1 CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, Mail Stop 126-347,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Pieter.Kok@jpl.nasa.gov; Ulvi.Yurtsever@jpl.nasa.gov RI Kok, Pieter/B-1658-2010 NR 22 TC 28 Z9 28 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD OCT 15 PY 2003 VL 68 IS 8 AR 085006 DI 10.1103/PhysRevD.68.085006 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 740VT UT WOS:000186422800056 ER PT J AU Hajj, GA Zuffada, C AF Hajj, GA Zuffada, C TI Theoretical description of a bistatic system for ocean altimetry using the GPS signal SO RADIO SCIENCE LA English DT Article DE GPS signal reflection; ocean remote sensing; ocean roughness; wind speeds ID GLOBAL POSITIONING SYSTEM; WIND-SPEED RETRIEVAL; ROUGH SURFACE; SEA-SURFACE; SCATTERING; MODEL AB [1] This paper presents the fundamental characteristics of bistatic altimetry performed using the Global Positioning System (GPS) signal scattered off the ocean surface and collected by a receiver in space. The advantage of the dense and rapid surface coverage afforded by the existing GPS constellation would enable new oceanographic applications such as eddy monitoring and the tracking of fast barotropic waves. To exploit the wealth of potentially available measurements, the paper provides a first cut at a system required to perform such measurements from space. In particular, the choice of pointing direction for the receiving antenna is discussed together with the implications in terms of instrument footprint and coherence time. The theoretical reflected signal is then derived by extension of the cross-correlation process used for direct GPS signals, and the characteristics of the leading edge are emphasized, to identify analogies and differences with the traditional altimetry waveform. In particular, the derivative of the leading edge is examined to assess the sensitivity to mean sea height, wind speed, and significant wave height. An overall range accuracy rms value is predicted for several antenna gains, pointing directions, and different geometric scenarios. When averaging many measurements, the range error is progressively reduced yielding predicted accuracies in sea height with associated spatial and temporal resolutions. The effect of wind speed and significant wave height on the received signal is discussed by performing simulations with a realistic range of these variables. The range accuracy versus receiving antenna gain and scattering direction is discussed, and a specific guideline on the gain necessary for altimetry from space is provided. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hajj, GA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 29 TC 41 Z9 48 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 J9 RADIO SCI JI Radio Sci. PD OCT 15 PY 2003 VL 38 IS 5 AR 1089 DI 10.1029/2002RS002787 PG 19 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA 735BA UT WOS:000186091100001 ER PT J AU Giglio, L Descloitres, J Justice, CO Kaufman, YJ AF Giglio, L Descloitres, J Justice, CO Kaufman, YJ TI An enhanced contextual fire detection algorithm for MODIS SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE fire; fire detection; MODIS ID INFRARED DATA; PRODUCTS; IDENTIFICATION; RESOLUTION AB Experience with the first 2 years of high quality data from the Moderate Resolution Imaging Spectroradiometer (MODIS) through quality control and validation has suggested several improvements to the original MODIS active fire detection algorithm described by Kaufman, Justice et al. [Journal of Geophysical Research 103 (1998) 32215]. In this paper, we present an improved replacement detection algorithm that offers increased sensitivity to smaller, cooler fires as well as a significantly lower false alarm rate. Performance of both the original and improved algorithm is established using a theoretical simulation and high-resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) scenes. In general, the new algorithm can detect fires roughly half the minimum size that could be detected with the original algorithm while having an overall false alarm rate 10-100 times smaller. (C) 2003 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. Univ Maryland, Dept Geog, College Pk, MD USA. RP Giglio, L (reprint author), NASA, Goddard Space Flight Ctr, Code 923, Greenbelt, MD 20771 USA. NR 21 TC 694 Z9 734 U1 12 U2 72 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 15 PY 2003 VL 87 IS 2-3 BP 273 EP 282 DI 10.1016/S0034-4257(03)00184-6 PG 10 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 741FE UT WOS:000186447400011 ER PT J AU French, AN Norman, JM Anderson, MC AF French, AN Norman, JM Anderson, MC TI A simple and fast atmospheric correction for spacebome remote sensing of surface temperature SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE thermal infrared; GOES; TIGR; SGP97; MODTRAN ID SENSED DATA; FLUXES; WINDOW; ABSORPTION; MODEL AB Accurate surface temperature retrieval using thermal infrared observations from satellites is important for surface energy balance modeling; however it is difficult to achieve without proper correction for atmospheric effects. Typically the atmospheric correction is obtained from radiosonde profiles and a radiative transfer model (RTM). But rigorous RTM processing is impractical for routine continental scale modeling because of long computational times. An alternative, simpler, and faster approach for correcting observations in the 10-12.5 mum band is developed from a previously published water vapor continuum absorption function. Using the RTM program MODTRAN as a reference, the function is calibrated against 159 radiosondes, and then validated against the TIGR radiosonde (1761 profiles) data set. Implementation of the calibrated absorption function usually produced larger temperature corrections than without calibration, an effect due to water vapor band type absorption and to non-water vapor constituents. The resulting surface temperature estimates, within 0.8 degreesC of MODTRAN estimates, were achieved at 15 x less processing time than MODTRAN. (C) 2003 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. Univ Wisconsin, Dept Soil Sci, Madison, WI 53706 USA. RP French, AN (reprint author), NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Code 974, Greenbelt, MD 20771 USA. RI Anderson, Martha/C-1720-2015 OI Anderson, Martha/0000-0003-0748-5525 NR 12 TC 24 Z9 27 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 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD OCT 15 PY 2003 VL 87 IS 2-3 BP 326 EP 333 DI 10.1016/j.rse.2003.08.001 PG 8 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 741FE UT WOS:000186447400015 ER PT J AU Podolske, JR Sachse, GW Diskin, GS AF Podolske, JR Sachse, GW Diskin, GS TI Calibration and data retrieval algorithms for the NASA Langley/Ames Diode Laser Hygrometer for the NASA Transport and Chemical Evolution Over the Pacific (TRACE-P) mission SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE laser spectroscopy; water vapor; algorithm ID LOWER STRATOSPHERE; FAST-RESPONSE; AIRCRAFT; SPECTROMETER AB [1] This paper describes the procedures and algorithms for the laboratory calibration and field data retrieval of the NASA Langley/Ames Diode Laser Hygrometer as implemented during the NASA Transport and Chemical Evolution Over the Pacific (TRACE-P) mission during February - April 2000. The calibration is based on a National Institute of Standards and Technology traceable dew point hygrometer using relatively high humidity and short optical path length. Two near-infrared water vapor absorption lines of widely different strengths are used to increase the dynamic range of the instrument in the course of a flight. The laboratory results are incorporated into a numerical model of the second harmonic spectrum for each of the two spectral window regions using spectroscopic parameters from the HITRAN database and other sources, allowing water vapor retrieval at upper tropospheric and lower stratospheric temperatures and humidity levels. The data retrieval algorithm is simple, numerically stable, and accurate. A comparison with other water vapor instruments on board the NASA DC-8 and ER-2 aircraft is presented. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Podolske, JR (reprint author), NASA, Ames Res Ctr, MS 245-5, Moffett Field, CA 94035 USA. EM james.r.podolske@nasa.gov; glen.w.sachse@nasa.gov; glenn.s.diskin@nasa.gov NR 15 TC 22 Z9 22 U1 1 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 14 PY 2003 VL 108 IS D20 AR 8792 DI 10.1029/2002JD003156 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 734ZM UT WOS:000186087900001 ER PT J AU Newburn, RL Bhaskaran, S Duxbury, TC Fraschetti, G Radey, T Schwochert, M AF Newburn, RL Bhaskaran, S Duxbury, TC Fraschetti, G Radey, T Schwochert, M TI Stardust Imaging Camera SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Stardust; comet 81P/Wild 2; CCD camera; imaging AB [1] The Stardust spacecraft is carrying an Imaging Camera, primarily for 81P/Wild 2 approach navigation, but the camera also will provide valuable data for P/Wild 2 nucleus characterization and about its activity. During an engineering readiness test, the camera already has provided useful scientific data about an asteroid, 5535 Annefrank. The camera utilizes spare parts from Cassini and Voyager as well as some inherited designs to provide an excellent, low-cost imaging system with a 1024 x 1024 pixel CCD detector and an f/3.5 lens with a 202 mm focal length. These yield a 3.5degrees x 3.5degrees field of view and, potentially, 12 arc second resolution. Spacecraft roll combined with a movable mirror permits safe autonomous body tracking. This capability was proven on Annefrank and will be used to acquire the desired data on P/Wild 2, with the spacecraft protected by a dust shield (a Whipple bumper) during that flyby. Details of the instrumental design and problems associated with its use make up the bulk of the paper. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Newburn, RL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 15 Z9 15 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD OCT 14 PY 2003 VL 108 IS E10 AR 8116 DI 10.1029/2003JE002081 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 735AF UT WOS:000186089600002 ER PT J AU Liou, K Newell, PT Meng, CI Wu, CC Lepping, RP AF Liou, K Newell, PT Meng, CI Wu, CC Lepping, RP TI Investigation of external triggering of substorms with Polar ultraviolet imager observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE substorm onset; substorm trigger; interplanetary shocks; northward IMF turnings ID INTERPLANETARY MAGNETIC-FIELD; MAGNETOSPHERIC SUBSTORMS; NORTHWARD TURNINGS; JANUARY 10; ONSET; INTENSIFICATIONS; DISTURBANCES; MAGNETOTAIL; ASSOCIATION; EXPANSIONS AB [1] The triggering mechanism(s) for the substorm expansion phase onset is one of the outstanding issues in magnetospheric physics. Previous studies have shown that an impingement of the high solar wind dynamic pressure may lead to the expansion phase onset of a substorm. These previous studies typically used a negative magnetic bay as the main proxy for a substorm, but we now know that some magnetic bays are associated not with substorms but with the enhancement of convection. Therefore it is reasonable to cast doubts on the compression trigger mechanism. In this study we use classical substorm onsets, "auroral breakups,'' which are the most reliable substorm onset indicator when identified with global auroral images, to reinvestigate this issue. We examine 43 interplanetary shock events that occurred between 1996 and 1999 with simultaneous global auroral images from the Polar ultraviolet imager images and the auroral electrojet indices. It is found, indeed, that similar to52% of the shocks produce magnetic bays (AL < - 100 nT). While most of the shocks enhance auroral luminosities, only 4 events (similar to 9%) appear to have an auroral breakup preceded by an SSC/SI by 20 min (two events by 10 min). These results strongly indicate interplanetary shocks can produce negative magnetic bays but not auroral breakups (thus christened "compression bays''). An examination of precisely timed interplanetary magnetic field ( IMF) during 11 substorms that occurred near the shock-induced SSCs/SIs indicates that northward turnings of IMF occurred more than 50% of time. Given such a low probability, it is concluded that shock compression is not likely to trigger substorms but enhances magnetospheric currents and auroral particle precipitation. In line with many previous study results, on the other hand, the northward turnings of IMF can be a plausible substorm triggering mechanism. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Alabama, CSPAR, Huntsville, AL 35899 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Liou, K (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. EM kan.liou@jhuapl.edu; patrick.newell@jhuapl.edu; ching.meng@jhuapl.edu; wuc@cspar.uah.edu; rpl@lepvax.gsfc.nasa.gov RI Liou, Kan/C-2089-2016 OI Liou, Kan/0000-0001-5277-7688 NR 52 TC 40 Z9 40 U1 1 U2 4 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 14 PY 2003 VL 108 IS A10 AR 1364 DI 10.1029/2003JA009984 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 735AR UT WOS:000186090600006 ER PT J AU Webb, PA Essex, EA AF Webb, PA Essex, EA TI Modifications to the Titheridge upper ionosphere and plasmasphere temperature model SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE electron temperature model; plasmasphere; topside ionosphere ID ELECTRON-TEMPERATURE; ATMOSPHERE AB [1] In 1998, J. E. Titheridge presented a computationally simple, yet accurate, model for the electron and ion temperatures (T-e and T-i) in the topside ionosphere and plasmasphere. The model is centered on a theoretically based equation with only two free parameters at a base height of 400 km: the electron temperature (T-o) and electron temperature gradient (G(o)). Titheridge fitted this equation to satellite T-e observations to determine the mean day and night variations in T-o and G(o) as functions of latitude and also estimated corrections for changes in solar flux, geomagnetic activity, and diurnal variations. Here we augment the satellite T-e data originally fitted by Titheridge with results from a more recent satellite-based empirical model and use the enlarged T-e data base to determine new functions for the day and night latitudinal variations in T-o and G(o). In addition, the solar flux correction has been modified so that increasing F-10.7 now corresponds to decreasing T-o rather than to increasing T-o. This modification yields better agreement with incoherent radar observations and the predictions of a theoretical model. Furthermore, corrections for seasonal variations and the separation of geographic and geomagnetic coordinates are introduced. All of the above modifications have been incorporated to improve the functional forms of the T-o and G(o) expressions, without noticeably decreasing the computational speed and elegance of the original Titheridge model. C1 La Trobe Univ, Dept Phys, Cooperat Res Ctr Satellite Syst, Bundoora, Vic 3086, Australia. RP Webb, PA (reprint author), NASA, Extraterr Phys Lab, Goddard Space Flight Ctr, Code 692, Greenbelt, MD 20771 USA. NR 13 TC 13 Z9 14 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 14 PY 2003 VL 108 IS A10 AR 1359 DI 10.1029/2002JA009754 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 735AR UT WOS:000186090600002 ER PT J AU Czuchlewski, KR Weissel, JK Kim, Y AF Czuchlewski, KR Weissel, JK Kim, Y TI Polarimetric synthetic aperture radar study of the Tsaoling landslide generated by the 1999 Chi-Chi earthquake, Taiwan SO JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE LA English DT Article DE radar; hazard; scattering; Chi-Chi; Taiwan; earthquake ID SAR DATA; CLASSIFICATION AB We employ L-band airborne synthetic aperture radar (SAR) polarimetry to detect surface changes produced by the Tsaoling landslide, the largest slope failure triggered by the September 1999 Chi-Chi earthquake in central Taiwan. Imaging polarimeters provide a complete description of the scattering properties of radar target materials. Resurfacing of forested hillslopes by landslides alters scattering mechanisms from those dominated by backscatter from trees to mechanisms associated with scatter from rough, bare surfaces. Scattering mechanism information on a per-pixel basis is extracted by decomposing matrices formed as the outer product of the complex scattering vector measured for each resolution cell. We classify surface cover type and thereby identify the extent of the landslide, using such polarimetric parameters as scattering entropy, anisotropy, and pedestal height, derived from the eigenvalues of the decomposition, as well as the weighted average scattering mechanism derived from the eigenvectors. We address the utility of full polarimetry versus dual polarimetry for landslide mapping purposes and show that fully polarimetric SAR is necessary for distinguishing water surfaces of varying roughness from the bare surfaces created by landsliding. We show that scattering entropy and average scattering mechanism, for example, can be used to identify the Tsaoling landslide source, run out area and impounded lakes as proficiently as maps obtained using satellite optical sensors, such as Landsat and the Indian Research Satellite. However, the operational advantages of radar over optical sensing techniques (namely, its day-night, all-weather data acquisition capability) suggest that SAR polarimetry could play a leading role in the rapid assessment of landslide disasters. C1 Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY 10964 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Czuchlewski, KR (reprint author), Columbia Univ, Lamont Doherty Earth Observ, 61 Route 9W, Palisades, NY 10964 USA. EM krodrig@ldeo.columbia.edu; jeffw@ldeo.columbia.edu; Yunjin.Kim@jpl.nasa.gov NR 28 TC 17 Z9 17 U1 0 U2 10 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 OCT 11 PY 2003 VL 108 IS F1 AR F16006 DI 10.1029/2003JF000037 PG 15 WC Geosciences, Multidisciplinary SC Geology GA 863MF UT WOS:000224565300003 ER PT J AU Hynes, RI Haswell, CA Cui, W Shrader, CR O'Brien, K Chaty, S Skillman, DR Patterson, J Horne, K AF Hynes, RI Haswell, CA Cui, W Shrader, CR O'Brien, K Chaty, S Skillman, DR Patterson, J Horne, K TI The remarkable rapid X-ray, ultraviolet, optical and infrared variability in the black hole XTE J1118+480 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; binaries : close; stars : individual : XTE J1118+480; ultraviolet : stars; X-rays : stars ID TRANSIENT XTE J1118+480; QUASI-PERIODIC OSCILLATIONS; BROAD-BAND SPECTRUM; GX 339-4; EMISSION; STATE; BINARIES; SUPERHUMPS; DISCOVERY; GX339-4 AB The transient black-hole binary XTE J1118 + 480 exhibited dramatic rapid variability at all wavelengths which were suitably observed during its 2000 April-July outburst. We examine time-resolved X-ray, ultraviolet, optical and infrared data spanning the plateau phase of the outburst. We find that both X-ray and infrared bands show large amplitude variability. The ultraviolet and optical variability is more subdued, but clearly correlated with that seen in the X-rays. The ultraviolet, at least, appears to be dominated by the continuum, although the lines are also variable. Using the X-ray variations as a reference point, we find that the ultraviolet (UV) variability at long wavelengths occurs later than that at short wavelengths. Uncertainty in the Hubble Space Telescope timing prohibits a determination of the absolute lag with respect to the X-rays, however. The transfer function is clearly not a delta-function, exhibiting significant repeatable structure. For the main signal we can rule out an origin in reprocessing on the companion star - the lack of variation in the lags is not consistent with this, given a relatively high orbital inclination. Weak reprocessing from the disc and/or companion star may be present, but is not required, and another component must dominate the variability. This could be variable synchrotron emission correlated with X-ray variability, consistent with our earlier interpretation of the infrared (IR) flux as due to synchrotron emission rather than thermal disc emission. In fact, the broad-band energy distribution of the variability from IR to X-rays is consistent with expectations of optically thin synchrotron emission. We also follow the evolution of the low-frequency quasi-periodic oscillation in X-rays, UV, and optical. Its properties at all wavelengths are similar, indicating a common origin. C1 Univ Texas, Dept Astron, Austin, TX 78712 USA. Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. Open Univ, Dept Phys & Astron, Milton Keynes MK7 6AA, Bucks, England. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Sterrekundig Inst, NL-1098 SJ Amsterdam, Netherlands. Univ St Andrews, Dept Phys & Astron, St Andrews KY16 9SS, Fife, Scotland. European So Observ, Santiago 19, Chile. Univ Paris 07, Federat APC, F-75005 Paris, France. CEA Saclay, Serv Astrophys, DSM, DAPNIA,SAp, F-91191 Gif Sur Yvette, France. Ctr Backyard Astrophys E, Laurel, MD 20723 USA. Columbia Univ, Dept Astron, New York, NY 10027 USA. RP Hynes, RI (reprint author), Univ Texas, Dept Astron, 1 Univ Stn C1400, Austin, TX 78712 USA. RI Skillman, David/C-8995-2013; OI Cui, Wei/0000-0002-6324-5772; Chaty, Sylvain/0000-0002-5769-8601 NR 59 TC 78 Z9 78 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 OCT 11 PY 2003 VL 345 IS 1 BP 292 EP 310 DI 10.1046/j.1365-8711.2003.06938.x PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 728UW UT WOS:000185735600025 ER PT J AU Djorgovski, SG Stern, D Mahabal, AA Brunner, R AF Djorgovski, SG Stern, D Mahabal, AA Brunner, R TI Discovery of a clustered quasar pair at z approximate to 5: Biased peaks in early structure formation SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; galaxies : formation; quasars : general; quasars : individual (SDSS 0338+0021, RD 657) ID QSO REDSHIFT SURVEY; TRANSIT GRISM SURVEY; DIGITAL SKY SURVEY; SURVEY COMMISSIONING DATA; SUBARU DEEP SURVEY; GALAXY FORMATION; POWER SPECTRUM; STAR-FORMATION; EVOLUTION; OBJECTS AB We report the discovery of a quasar at z = 4.96 +/- 0.03 within a few Mpc of the quasar SDSS 0338+0021 at z = 5.02 +/- 0.02. The newly found quasar has SDSS i and z magnitudes of approximate to21.2, and an estimated absolute magnitude M-B approximate to -25.2. The projected separation on the sky is 196", and the redshift difference Deltaz = 0.063 +/- 0.008. The probability of finding this quasar pair by chance in the absence of clustering in this particular volume is similar to10(-4) to 10(-3). We conclude that the two objects probably mark a large-scale structure, possibly a protocluster, at z approximate to 5. This is the most distant such structure currently known. Our search in the field of 13 other QSOs at z greater than or similar to 4.8 so far has not resulted in any detections of comparable luminous QSO pairs, and it is thus not yet clear how representative is this structure at z approximate to 5. However, along with the other evidence for clustering of quasars and young galaxies at somewhat lower redshifts, the observations are at least qualitatively consistent with a strong biasing of the first luminous and massive objects, in agreement with general predictions of theoretical models. More extensive searches for clustered quasars and luminous galaxies at these redshifts will provide valuable empirical constraints for our understanding of early galaxy and structure formation. C1 CALTECH, Palomar Observ 105 24, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Palomar Observ 105 24, Pasadena, CA 91125 USA. EM george@astro.caltech.edu; stern@zwolfkinder.jpl.nasa.gov; aam@astro.caltech.edu; rb@astro.caltech.edu NR 56 TC 26 Z9 26 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP 67 EP 71 DI 10.1086/377524 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DQ UT WOS:000185814300006 ER PT J AU Yaqoob, T George, IM Kallman, TR Padmanabhan, U Weaver, KA Turner, TJ AF Yaqoob, T George, IM Kallman, TR Padmanabhan, U Weaver, KA Turner, TJ TI Fe XXV and Fe XXVI diagnostics of the black hole and accretion disk in active galaxies: Chandra time-resolved grating spectroscopy of NGC 7314 SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; galaxies : active; line : formation; line : profiles; X-rays : galaxies; X-rays : individual ( NGC 7314) ID X-RAY REFLECTION; LINE SEYFERT-1 GALAXIES; ALPHA EMISSION-LINE; GALACTIC NUCLEI; IRON LINE; K-ALPHA; COMPTON REFLECTION; XMM-NEWTON; BEPPOSAX OBSERVATIONS; ASCA OBSERVATIONS AB We report the detection of Fe XXV and Fe XXVI Kalpha emission lines from a Chandra High Energy Transmission Grating Spectrometer observation of the narrow-line Seyfert 1 galaxy NGC 7314, made simultaneously with the Rossi X-Ray Timing Explorer. The lines are redshifted (cz similar to 1500 km s(-1)) relative to the systemic velocity and unresolved by the gratings. We argue that the lines originate in a near face-on (<7&DEG;) disk having a radial line emissivity flatter than r(-2). Line emission from ionization states of Fe in the range &SIM;Fe I up to Fe XXVI is observed. The ionization balance of Fe responds to continuum variations on timescales of less than 12.5 ks, supporting an origin of the lines close to the X-ray source. We present additional, detailed diagnostics from this rich data set. These results identify NGC 7314 as a key source to study in the future if we are to pursue reverberation mapping of spacetime near black hole event horizons. This is because it is first necessary to understand the ionization structure of accretion disks and the relation between the X-ray continuum and Fe Kα line emission. However, we also describe how our results are suggestive of a means of measuring black hole spin without a knowledge of the relation between the continuum and line emission. Finally, these data emphasize that one can study strong gravity with narrow ( as opposed to very broad) disk lines. In fact, narrow lines offer higher precision, given sufficient energy resolution. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Baltimore, MD 21250 USA. RP Yaqoob, T (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NR 65 TC 74 Z9 74 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP 85 EP 104 DI 10.1086/377687 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DQ UT WOS:000185814300008 ER PT J AU Furusho, T Yamasaki, NY Ohashi, T AF Furusho, T Yamasaki, NY Ohashi, T TI Chandra observation of the core of the galaxy cluster AWM 7 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : individual (AWM7); galaxies : individual (NGC 1129) intergalactic medium; X-rays : galaxies ID CENTAURUS CLUSTER; HIGH-RESOLUTION; COOLING FLOWS; TEMPERATURE; CONSTRAINTS; HYDRA; MAPS; GAS; CD AB We present results from a Chandra observation of the core region of the nearby X-ray-bright galaxy cluster AWM 7. There are bloblike substructures, which are seen in the energy band 2-10 keV, within 10 kpc (20") of the cD galaxy NGC 1129, and the brightest subpeak has a spatial extent more than 4 kpc. We also notice that the central soft X-ray peak is slightly offset from the optical center by 1 kpc. These structures have no correlated features in optical, infrared, or radio bands. The energy spectrum of the hard subpeak indicates a temperature higher than 3 keV with a metallicity less than 0.3 solar, or a power-law spectrum with photon index similar to1.2. A hardness ratio map and a narrow Fe K band image jointly indicate two Fe-rich blobs symmetrically located around the cD galaxy, with the direction perpendicular to the subpeak direction. In larger scales (r<60 kpc), the temperature gradually drops from 4 to 2 keV toward the cluster center, and the metal abundance rises steeply to a peak of 1.5 solar at r&AP;7 kpc. These results indicate that a dynamical process is going on in the central region of AWM 7, which probably creates heated gas blobs and drives metal injection. C1 NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo 1920397, Japan. RP Furusho, T (reprint author), NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. RI Yamasaki, Noriko/C-2252-2008 NR 26 TC 21 Z9 21 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP 181 EP 189 DI 10.1086/377532 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DQ UT WOS:000185814300015 ER PT J AU Aguirre, JE Bezaire, JJ Cheng, ES Cottingham, DA Cordone, SS Crawford, TM Fixsen, DJ Knox, L Meyer, SS Norgaard-Nielsen, HU Silverberg, RF Timbie, P Wilson, GW AF Aguirre, JE Bezaire, JJ Cheng, ES Cottingham, DA Cordone, SS Crawford, TM Fixsen, DJ Knox, L Meyer, SS Norgaard-Nielsen, HU Silverberg, RF Timbie, P Wilson, GW TI The spectrum of integrated millimeter flux of the Magellanic Clouds and 30 Doradus from Tophat and Dirbe data SO ASTROPHYSICAL JOURNAL LA English DT Article DE balloons; dust, extinction; galaxies : ISM; infrared : galaxies; Magellanic Clouds ID BACKGROUND EXPERIMENT SEARCH; GALACTIC DUST EMISSION; UNIVERSE GALAXY SURVEY; INFRARED-EMISSION; INTERSTELLAR DUST; EXTINCTION; COBE; GRAINS; SCUBA; DETECTIONS AB We present measurements of the integrated flux relative to the local background of the Large and Small Magellanic Clouds and the region 30 Doradus (the Tarantula Nebula) in the LMC in four frequency bands centered at 245, 400, 460, and 630 GHz, based on observations made with the TopHat telescope. We combine these observations with the corresponding measurements for the DIRBE bands 8, 9, and 10 to cover the frequency range 245-3000 GHz (100-1220 mum) for these objects. We present spectra for all three objects and fit these spectra to a single-component graybody emission model and report best-fit dust temperatures, optical depths, and emissivity power-law indices, and we compare these results with other measurements in these regions and elsewhere. Using published dust grain opacities, we estimate the mass of the measured dust component in the three regions. C1 Univ Chicago, Dept Phys, Chicago, IL 60637 USA. Conceptual Analyt LLC, Glenn Dale, MD 20769 USA. NASA, Global Sci & Technol Inc, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Univ Chicago, Dept Astron, Chicago, IL 60637 USA. NASA, SSAI, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Danish Space Res Inst, DK-2100 Copenhagen, Denmark. Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. RP Aguirre, JE (reprint author), Univ Chicago, Dept Phys, 5640 S Ellis Ave, Chicago, IL 60637 USA. NR 43 TC 33 Z9 33 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP 273 EP 286 DI 10.1086/377601 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DQ UT WOS:000185814300022 ER PT J AU Woods, PM Kouveliotou, C Gogus, E Finger, MH Feroci, M Mereghetti, S Swank, JH Hurley, K Heise, J Smith, D Frontera, F Guidorzi, C Thompson, C AF Woods, PM Kouveliotou, C Gogus, E Finger, MH Feroci, M Mereghetti, S Swank, JH Hurley, K Heise, J Smith, D Frontera, F Guidorzi, C Thompson, C TI The 2001 April burst activation of SGR 1900+14: Pulse properties and torque SO ASTROPHYSICAL JOURNAL LA English DT Article DE pulsars : general; stars : individual (SGR 1900+14); X-rays : bursts ID GAMMA-REPEATER SGR-1900+14; X-RAY PULSAR; MAGNETIZED NEUTRON-STARS; VARIABLE SPIN-DOWN; 1998 AUGUST 27; RADIATIVE MECHANISM; GIANT FLARE; OUTBURST; EMISSION; BEPPOSAX AB We report on observations of SGR 1900+14 made with the Rossi X-Ray Timing Explorer (RXTE) and BeppoSAX during the 2001 April burst activation of the source. Using these data, we measure the spin-down torque on the star and confirm earlier findings that the torque and burst activity are not directly correlated. We compare the X-ray pulse profile to the gamma-ray profile during the April 18 intermediate. are and show that (1) their shapes are similar and (1) the gamma-ray profile aligns closely in phase with the X-ray pulsations. The good phase alignment of the gamma-ray and X-ray profiles suggests that there was no rapid spin-down following this. are of the magnitude inferred for the August 27 giant flare. We discuss how these observations further constrain magnetic field reconfiguration models for the large flares of SGRs. C1 Univ Space Res Assoc, Columbia, MD USA. Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. CNR, Ist Astrofis Spaziale & Fis Cosm, Rome, Italy. CNR, Ist Astrofis Spaziale & Fis Cosm, Sez Milano, Milan, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. SRON, Natl Inst Space Res, NL-3584 CA Utrecht, Netherlands. Univ Michigan, Dept Phys, Ann Arbor, MI 48109 USA. CNR, Ist Tecnol & Studio Radiaz Extraterr, I-40129 Bologna, Italy. Univ Ferrara, Dipartimento Fis, I-44100 Ferrara, Italy. Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. RP Woods, PM (reprint author), Univ Space Res Assoc, Columbia, MD USA. RI Swank, Jean/F-2693-2012; OI Feroci, Marco/0000-0002-7617-3421; MEREGHETTI, SANDRO/0000-0003-3259-7801 NR 34 TC 11 Z9 11 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP 464 EP 469 DI 10.1086/376891 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DQ UT WOS:000185814300039 ER PT J AU Kouveliotou, C Eichler, D Woods, PM Lyubarsky, Y Patel, SK Gogus, E van der Klis, M Tennant, A Wachter, S Hurley, K AF Kouveliotou, C Eichler, D Woods, PM Lyubarsky, Y Patel, SK Gogus, E van der Klis, M Tennant, A Wachter, S Hurley, K TI Unraveling the cooling trend of the soft gamma repeater SGR 1627-41 SO ASTROPHYSICAL JOURNAL LA English DT Article ID SGR-1627-41 AB SGR 1627 - 41 was discovered in 1998 after a single active episode that lasted similar to 6 weeks. We report here our monitoring results of the decay trend of the persistent X-ray luminosity of the source during the last 5 years. We find an initial temporal power-law decay with index 0.47, reaching a plateau that is followed by a sharp (factor of 10) flux decline similar to 800 days after the source activation. The source spectrum is best described during the entire period by a single power law with high absorption [N-H = 9.07(7) x 10(22) cm(-2)]; the spectral index, however, varies dramatically between 2.2 and 3.8 spanning the entire range for all known soft gamma repeater sources. We discuss the cooling behavior of the neutron star assuming a deep crustal heating initiated by the burst activity of the source during 1998. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35805 USA. Univ Space Res Assoc, NSSTC, Huntsville, AL 35805 USA. Ben Gurion Univ Negev, Dept Phys, IL-84105 Beer Sheva, Israel. Sabanci Univ, Fac Engn & Nat Sci, TR-34956 Istanbul, Turkey. Univ Amsterdam, Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Univ Amsterdam, Ctr High Energy Astrophys, NL-1098 SJ Amsterdam, Netherlands. CALTECH MS 220 6, Space Infrared Telescope Facil, Ctr Sci, Pasadena, CA 91125 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP NASA, George C Marshall Space Flight Ctr, SD-50,320 Sparkman Dr, Huntsville, AL 35805 USA. EM chryssa.kouveliotou@nasa.gov RI LYUBARSKY, YURY/F-2362-2012 NR 11 TC 54 Z9 54 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 OCT 10 PY 2003 VL 596 IS 1 BP L79 EP L82 DI 10.1086/379187 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DT UT WOS:000185814500020 ER PT J AU Steffen, AT Barger, AJ Cowie, LL Mushotzky, RF Yang, Y AF Steffen, AT Barger, AJ Cowie, LL Mushotzky, RF Yang, Y TI The changing active galactic nucleus population SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; galaxies : active; galaxies : evolution; galaxies : formation ID DEEP FIELD-NORTH; X-RAY SOURCES; LUMINOSITY FUNCTION; STARBURST GALAXIES; SKY; EVOLUTION; SAMPLE AB We investigate how the fraction of broad-line sources in the active galactic nucleus (AGN) population changes with X-ray luminosity and redshift. We first construct the rest-frame hard-energy (2-8 keV) X-ray luminosity function (HXLF) at z=0.1-1 using Chandra Lockman Hole-Northwest wide-area data, Chandra Deep Field-North 2 Ms data, other Chandra deep field data, and the ASCA Large Sky Survey data. We find that broad-line AGNs dominate above similar to3x10(43) ergs s(-1) and have a mean luminosity of 1.3x10(44) ergs s(-1). Type II AGNs can become an important component of the X-ray population only at Seyfert-like X-ray luminosities. We then construct z=0.1-0.5 and z=0.5-1 HXLFs and compare them with both the local HXLF measured from HEAO 1 A2 survey data and the z=1.5-3 HXLF measured from soft-energy (0.5-2 keV) Chandra and ROSAT data. We find that the number density of L-X>10(44) ergs s(-1) sources (quasars) steadily declines with decreasing redshift, while the number density of LX=10(43)-10(44) ergs s(-1) sources peaks at z=0.5-1. Strikingly, however, the number density of broad-line AGNs remains roughly constant with redshift while their average luminosities decline at the lower redshifts, showing another example of cosmic downsizing. C1 Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. Univ Hawaii, Dept Phys & Astron, Honolulu, HI 96822 USA. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP Steffen, AT (reprint author), Univ Wisconsin, Dept Astron, 475 N Charter St, Madison, WI 53706 USA. NR 19 TC 146 Z9 147 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP L23 EP L26 DI 10.1086/379142 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DT UT WOS:000185814500006 ER PT J AU Stern, D Hall, PB Barrientos, LF Bunker, AJ Elston, R Ledlow, MJ Raines, SN Willis, J AF Stern, D Hall, PB Barrientos, LF Bunker, AJ Elston, R Ledlow, MJ Raines, SN Willis, J TI Gemini-South plus FLAMINGOS demonstration science: Near-infrared spectroscopy of the z=5.77 quasar SDSS J083643.85+005453.3 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; quasars : general; quasars : individual (SDSS J083643.85+005453.3) ID DIGITAL SKY SURVEY; HIGH-REDSHIFT QUASARS; PROBE WMAP OBSERVATIONS; BLACK-HOLE MASSES; ELEMENTAL ABUNDANCES; IRON EMISSION; Z-SIMILAR-TO-6; SPECTROMETER; DISCOVERY; EVOLUTION AB We report an infrared 1-1.8 mum (J+H-band), low-resolution (R=450) spectrogram of the highest redshift radio-loud quasar currently known, SDSS J083643.85+005453.3, obtained during the spectroscopic commissioning run of the FLAMINGOS multiobject, near-IR spectrograph at the 8 m Gemini-South Observatory. These data show broad emission from both C IV lambda1549 and C III] lambda1909, with strengths comparable to lower redshift quasar composite spectra. The implication is that there is substantial enrichment of the quasar environment, even at times less than a billion years after the big bang. The redshift derived from these features is z=5.774+/-0.0003, more accurate and slightly lower than the z=5.82 reported in the discovery paper based on the partially absorbed Lyalpha emission line. The infrared continuum is significantly redder than lower redshift quasar composites. Fitting the spectrum from 1.0 to 1.7 mum with a power law f(v) proportional to nu(-alpha), the derived power-law index is alpha=1.55 compared to the average continuum spectral index =0.44 derived from the first Sloan Digital Sky Survey composite quasar. Assuming an SMC-like extinction curve, we infer a color excess of E(B-V)=0.09+/-0.01. Only approximate to6% of quasars in the optically selected Sloan Digital Sky Survey show comparable levels of dust reddening. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Pontificia Univ Catolica Chile, Fac Fis, Dept Astron, Santiago 22, Chile. Princeton Univ Observ, Princeton, NJ 08544 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. Gemini S Observ, La Serena, Chile. European So Observ, Santiago 19, Chile. RP Stern, D (reprint author), CALTECH, Jet Prop Lab, MS 169-506, Pasadena, CA 91109 USA. NR 31 TC 10 Z9 10 U1 0 U2 3 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP L39 EP L42 DI 10.1086/379206 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DT UT WOS:000185814500010 ER PT J AU Strohmayer, TE Markwardt, CB Swank, JH in't Zand, J AF Strohmayer, TE Markwardt, CB Swank, JH in't Zand, J TI X-ray bursts from the accreting millisecond pulsar XTE J1814-338 SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; stars : individual (XTE J1814-338); stars : neutron; stars : rotation; X-rays : bursts; X-rays : stars ID NEUTRON-STARS; BRIGHTNESS OSCILLATIONS; FREQUENCY; EVOLUTION; AMPLITUDE; EMISSION AB Since the discovery of the accreting millisecond pulsar XTE J1814 - 338, a total of 27 thermonuclear bursts have been observed from the source with the Proportional Counter Array on board the Rossi X-Ray Timing Explorer. Spectroscopy of the bursts, as well as the presence of continuous burst oscillations, suggests that all but one of the bursts are sub-Eddington. The remaining burst has the largest peak bolometric flux of 2.64 x 10(-8) ergs s(-1) cm(-2), as well as a gap in the burst oscillations, similar to that seen in Eddington-limited bursts from other sources. Assuming that this burst was Eddington limited, we obtain a source distance of approximate to 8 kpc. All the bursts show coherent oscillations at the 314.4 Hz spin frequency. The burst oscillations are strongly frequency and phase locked to the persistent pulsations. Only two bursts show evidence for frequency drift in the first few seconds following burst onset. In both cases, the initial drift corresponds to a spin-down of a few tenths of a hertz. The large oscillation amplitude during the bursts confirms that the burst flux is modulated at the spin frequency. We detect, for the first time, a significant first harmonic component in burst oscillations. The ratio of count rate in the first harmonic to that in the fundamental can be greater than 0.25 and is, on average, less than that of the persistent pulsations. If the pulsations result from a single bright region on the surface, the harmonic strength suggests that the burst emission is beamed, perhaps because of a stronger magnetic field than in nonpulsing low-mass X-ray binaries. Alternatively, the harmonic content could result from a geometry with two bright regions. C1 NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, College Pk, MD 20772 USA. SRON, NL-3584 CA Utrecht, Netherlands. RP Strohmayer, TE (reprint author), NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI Swank, Jean/F-2693-2012 NR 18 TC 101 Z9 101 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 10 PY 2003 VL 596 IS 1 BP L67 EP L70 DI 10.1086/379158 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 730DT UT WOS:000185814500017 ER PT J AU Shindell, DT Faluvegi, G Bell, N AF Shindell, DT Faluvegi, G Bell, N TI Preindustrial-to-present-day radiative forcing by tropospheric ozone from improved simulations with the GISS chemistry-climate GCM SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID GENERAL-CIRCULATION MODEL; SURFACE OZONE; GLOBAL SIMULATION; GODDARD-INSTITUTE; ANTHROPOGENIC EMISSIONS; ATMOSPHERIC CHEMISTRY; METHANE CYCLE; IMPACT; DISTRIBUTIONS; TRANSPORT AB Improved estimates of the radiative forcing from tropospheric ozone increases since the preindustrial have been calculated with the tropospheric chemistry model used at the Goddard Institute for Space Studies (GISS) within the GISS general circulation model (GCM). The chemistry in this model has been expanded to include simplified representations of peroxyacetylnitrates and non-methane hydrocarbons in addition to background NOx-HOx-O-x-CO-CH4 chemistry. The GCM has improved resolution and physics in the boundary layer, improved resolution near the tropopause, and now contains a full representation of stratospheric dynamics. Simulations of present-day conditions show that this coupled chemistry-climate model is better able to reproduce observed tropospheric ozone, especially in the tropopause region, which is critical to climate forcing. Comparison with preindustrial simulations gives a global annual average radiative forcing due to tropospheric ozone increases of 0.30 W/m(2) with standard assumptions for preindustrial emissions. Locally, the forcing reaches more than 0.8 W/m(2) in parts of the northern subtropics during spring and summer, and is more than 0.6 W/m(2) through nearly all the Northern subtropics and mid-latitudes during summer. An alternative preindustrial simulation with soil NOx emissions reduced by two-thirds and emissions of isoprene, paraffins and alkenes from vegetation increased by 50% gives a forcing of 0.33 W/m(2). Given the large uncertainties in preindustrial ozone amounts, the true value may lie well outside this range. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY USA. RP NASA, Goddard Inst Space Studies, New York, NY 10025 USA. EM dshindell@giss.nasa.gov RI Shindell, Drew/D-4636-2012; Unger, Nadine/M-9360-2015 NR 72 TC 66 Z9 68 U1 0 U2 6 PU COPERNICUS GESELLSCHAFT MBH PI GOTTINGEN PA BAHNHOFSALLEE 1E, GOTTINGEN, 37081, GERMANY SN 1680-7316 EI 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD OCT 10 PY 2003 VL 3 BP 1675 EP 1702 PG 28 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 731RX UT WOS:000185901200002 ER PT J AU Chandler, MO Avanov, LA AF Chandler, MO Avanov, LA TI Observations at low latitudes of magnetic merging signatures within a flux transfer event during a northward interplanetary magnetic field SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE magnetopause; flux transfer event; boundary layer; magnetic merging ID DAYSIDE MAGNETOPAUSE; BOUNDARY-LAYER; AMPTE/IRM OBSERVATIONS; OUTER MAGNETOSPHERE; RECONNECTION; CONVECTION; SHEAR; ION; SPACECRAFT; TRANSIENT AB [1] Flux transfer events (FTE) have been postulated to result from transient magnetic merging. If so, the ion distributions within an event should exhibit features known to result from merging. Observations of an FTE by instruments on the Polar spacecraft revealed classical merging signatures that included: (1) D-shaped, accelerated, magnetosheath ion distributions, (2) a well-defined de Hoffman-Teller frame, (3) local stress balance, and (4) a P-N magnetic field signature. This FTE was observed near the magnetic equator at similar to13 magnetic local time under conditions of a strongly northward interplanetary magnetic field (IMF) (clock angle of <10&DEG;). The nature of the ion distributions and the consistency of the measured cutoff speed with that calculated from the measured local magnetic field and the derived de Hoffman-Teller speed show the ion injection to be local. Coupled with the northward IMF, these results lead to the conclusion that component merging in the low-latitude region was responsible for the FTE. C1 NASA, Natl Space Sci & Technol Ctr, George C Marshall Space Flight Ctr, Huntsville, AL 35805 USA. Russian Acad Sci, Space Res Inst, Moscow 117997, Russia. RP Chandler, MO (reprint author), NASA, Natl Space Sci & Technol Ctr, George C Marshall Space Flight Ctr, Space Sci SD50,320 Sparkman Dr, Huntsville, AL 35805 USA. NR 48 TC 7 Z9 7 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 OCT 10 PY 2003 VL 108 IS A10 AR 1358 DI 10.1029/2003JA009852 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 732GD UT WOS:000185931700001 ER PT J AU Hilder, TL Tou, JCL Grindeland, RE Wade, CE Graves, LM AF Hilder, TL Tou, JCL Grindeland, RE Wade, CE Graves, LM TI Phosphorylation of insulin receptor substrate-1 serine 307 correlates with JNK activity in atrophic skeletal muscle SO FEBS LETTERS LA English DT Article DE skeletal muscle atrophy; hindlimb suspension; insulin resistance; insulin receptor substrate; c-Jun NH2-terminal kinase ID GLUCOSE-TRANSPORT; KINASE-ACTIVITY; TYROSINE PHOSPHORYLATION; DEGRADATION; RESISTANCE; PATHWAY; RAT; SPACEFLIGHT; EXPRESSION; ACTIVATION AB c-Jun NH2-terminal kinase (JNK) has been shown to negatively regulate insulin signaling through serine phosphorylation of residue 307 within the insulin receptor substrate-1 (IRS-1) in adipose and liver tissue. Using a rat hindlimb suspension model for muscle disuse atrophy, we found that JNK activity was significantly elevated in atrophic soleus muscle and that IRS-1 was phosphorylated on Ser(307) prior to the degradation of the IRS-1 protein. Moreover, we observed a corresponding reduction in Akt activity, providing biochemical evidence for the development of insulin resistance in atrophic skeletal muscle. (C) 2003 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved. C1 Univ N Carolina, Dept Pharmacol, Chapel Hill, NC 27599 USA. NASA, Ames Res Ctr, Div Life Sci, Wyle Labs, Moffett Field, CA 94035 USA. RP Graves, LM (reprint author), Univ N Carolina, Dept Pharmacol, CB 7365, Chapel Hill, NC 27599 USA. NR 48 TC 40 Z9 41 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0014-5793 J9 FEBS LETT JI FEBS Lett. PD OCT 9 PY 2003 VL 553 IS 1-2 BP 63 EP 67 DI 10.1016/S0014-5793(03)00972-4 PG 5 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 731HE UT WOS:000185877600012 PM 14550547 ER PT J AU Smith, EJ Marsden, RG AF Smith, EJ Marsden, RG TI Ulysses observations at solar maximum: Introduction SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID WIND; PROPAGATION; PARTICLES AB [1] Observations during Ulysses' second solar orbit reveal basic changes between solar minimum and maximum. Fast high latitude wind disappeared in the southern hemisphere allowing slow wind to expand to all latitudes. In the north polar cap, both fast wind and a polar coronal hole were present. The magnetic field polarity reversal was detected in the north polar cap. The source dipole of the heliospheric magnetic field had a nearly equatorial, rather than an axial, orientation. Coronal mass ejections occurred at all latitudes including fast wind from the polar cap. Analysis of magnetic clouds confirmed their close association with solar filaments. The electron-proton ratio of galactic cosmic rays changed at the magnetic polarity reversal. Solar Energetic Particles were present at all latitudes including the formation of particle "reservoirs'' that require access to all latitudes and longitudes. Reservoir particles are also present at solar minimum at low flux levels. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. ESTEC, ESA, Directorate Sci Programs, Noordwijk, Netherlands. RP Smith, EJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM edward.j.smith@jpl.nasa.gov NR 16 TC 5 Z9 6 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 8 PY 2003 VL 30 IS 19 AR 8027 DI 10.1029/2003GL018223 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 732DM UT WOS:000185925600005 ER PT J AU Lepping, RP Berdichevsky, DB Ferguson, TJ AF Lepping, RP Berdichevsky, DB Ferguson, TJ TI Estimated errors in magnetic cloud model fit parameters with force-free cylindrically symmetric assumptions SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE magnetic clouds; magnetic fields; solar wind; force free; WIND ID FLUX ROPES; OCTOBER 18-19; SOLAR-WIND; FIELD; PLASMA; SHOCK; AU AB This paper briefly reviews our earlier study done on estimated errors in various output fit parameters resulting from a specific force-free interplanetary magnetic cloud model [Lepping et al., 1990], applied to randomly noised-up fields of simulated clouds, and shows that such random noise simulation studies are inadequate. It then proceeds to carry out an error study of the same model output parameters on the basis of more realistic input magnetic field noise sets derived from actual clouds observed in WIND data over the years 1995 to 1998. In this part of the study, 1824 "noised-up'' simulated clouds are produced for use in the same force-free cloud model to study the spread in values for each of 7 model parameters, plus associated quantities, as a function of noise level. Four noise levels are used with RMSs of 0.5, 2.0 (typical level), 3.0, and 4.0 nT per field component of input bias-free fluctuation fields. These are based on manipulation of difference fields from 19 actual magnetic clouds, where a difference field is defined as the vector difference between the observational field and that from the original model fit for each actual cloud. The averages and RMSs of 240 output (model fit) parameter distributions are produced and discussed. The study determines how the model fit parameters, and especially their distributions, vary as a function of various input noise levels and of the resulting least squares (chi(2))(1/2) values for various exact input parameters, such as the cloud's axial attitude and the closest approach distance of the spacecraft. Practical goals were to better understand the fit program's limitations and to provide a prescription for estimating future errors in specific magnetic cloud (and probably magnetotail flux rope) fittings. The degree of symmetry in the model solution is used along with (chi(2))(1/2) to judge the quality of the fit. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. EER Syst Inc, L3 Commun, Largo, MD 20774 USA. Linganore High Sch, Frederick, MD USA. RP Lepping, RP (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. NR 36 TC 22 Z9 23 U1 1 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 OCT 8 PY 2003 VL 108 IS A10 AR 1356 DI 10.1029/2002JA009657 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 732GA UT WOS:000185931400001 ER PT J AU Anderson, MS AF Anderson, MS TI Enhanced infrared absorption with dielectric nanoparticles SO APPLIED PHYSICS LETTERS LA English DT Article ID SPECTROSCOPY; MICROSCOPY; RESOLUTION; PARTICLES AB Enhanced infrared absorption is demonstrated for anthracene coating polar dielectric nanoparticles of silicon carbide and aluminum oxide. An enhancement factor greater than 100 was measured near the surface of silicon carbide particles. This is the result of the enhanced optical fields at the surface of the particles when illuminated at the surface phonon resonance frequencies. This phonon resonance effect is analogous to plasmon resonance that is the basis of surface enhanced infrared absorption and surface enhanced Raman scattering. The results have implications for near-field microscopy, the characterization of nano-optical devices, and chemical sensing. In addition, the methodology used for surface phonon analysis of particles is useful for simulating comet and interstellar dust spectra. (C) 2003 American Institute of Physics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Anderson, MS (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,M-S 125-109, Pasadena, CA 91109 USA. NR 19 TC 64 Z9 67 U1 1 U2 30 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD OCT 6 PY 2003 VL 83 IS 14 BP 2964 EP 2966 DI 10.1063/1.1615311 PG 3 WC Physics, Applied SC Physics GA 727NB UT WOS:000185664000078 ER PT J AU Zerefos, CS Eleftheratos, K Balis, DS Zanis, P Tselioudis, G Meleti, C AF Zerefos, CS Eleftheratos, K Balis, DS Zanis, P Tselioudis, G Meleti, C TI Evidence of impact of aviation on cirrus cloud formation SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID ICE-SUPERSATURATED REGIONS; UPPER TROPOSPHERE; GLOBAL DISTRIBUTION; SUBVISIBLE CIRRUS; PART I; CLIMATE; PERSISTENCE; CONTRAILS; ISCCP AB This work examines changes in cirrus cloud cover (CCC) in possible association with aviation activities at congested air corridors. The analysis is based on the latest version of the International Satellite Cloud Climatology Project D2 data set and covers the period 1984-1998. Over the studied areas, the effect of large-scale modes of natural climate variability such as ENSO, QBO and NAO as well as the possible influence of the tropopause variability, were first removed from the cloud data set in order to calculate long-term changes of observed cirrus cloudiness. The results show increasing trends in (CCC) between 1984 and 1998 over the high air traffic corridors of North America, North Atlantic and Europe. Of these upward trends, only in the summertime over the North Atlantic and only in the wintertime over North America are statistically significant (exceeding +2.0% per decade). Over adjacent locations with low air traffic, the calculated trends are statistically insignificant and in most cases negative both during winter and summer in the regions studied. These negative trends, over low air traffic regions, are consistent with the observed large scale negative trends seen in (CCC) over most of the northern middle latitudes and over the tropics. Moreover, further investigation of vertical velocities over high and low air traffic regions provide evidence that the trends of opposite signs in (CCC) over these regions, do not seem to be caused by different trends in dynamics. It is also shown that the longitudinal distribution of decadal changes in (CCC) along the latitude belt centered at the North Atlantic air corridor, parallels the spatial distribution of fuel consumption from highflying air traffic, providing an independent test of possible impact of aviation on contrail cirrus formation. The correlation between the fuel consumption and the longitudinal variability of (CCC) is significant (+0.7) over the middle latitudes but not over the tropics. This could be explained by the fact that over the tropics the variability of (CCC) is dominated by dynamics while at middle latitudes microphysics explain most of its variability. Results from this study are compared with other studies and for different periods of records and it appears that there exists general agreement as to the evidence of a possible aviation effect on high cloud positive trends over regions with congested air traffic. C1 Univ Athens, Fac Geol, Lab Climatol & Atmospher Environm, Athens, Greece. Aristotle Univ Thessaloniki, Lab Atmospher Phys, Thessaloniki, Greece. Acad Athens, Res Ctr Atmospher Phys & Climatol, Athens, Greece. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Zerefos, CS (reprint author), Univ Athens, Fac Geol, Lab Climatol & Atmospher Environm, Athens, Greece. EM zerefos@geol.uoa.gr RI Zanis, Prodromos/B-5598-2015; OI Balis, Dimitris/0000-0003-1161-7746 NR 34 TC 45 Z9 46 U1 0 U2 1 PU COPERNICUS GESELLSCHAFT MBH PI GOTTINGEN PA BAHNHOFSALLEE 1E, GOTTINGEN, 37081, GERMANY SN 1680-7316 EI 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD OCT 6 PY 2003 VL 3 BP 1633 EP 1644 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 731RN UT WOS:000185900400002 ER PT J AU Menon, M Andriotis, AN Srivastava, D Ponomareva, I Chernozatonskii, LA AF Menon, M Andriotis, AN Srivastava, D Ponomareva, I Chernozatonskii, LA TI Carbon nanotube "T junctions": Formation pathways and conductivity SO PHYSICAL REVIEW LETTERS LA English DT Article AB Using tight-binding molecular dynamics we simulate the formation of single wall carbon nanotube T junctions via the fusing of two nanotubes. We propose energetically efficient pathways for this process in which all atoms maintain their sp(2) arrangements throughout. Recent experimental advances have greatly increased the plausibility of synthesizing T junctions as proposed in the simulations. We further report I-V characteristics of the formed junctions. C1 Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. Univ Kentucky, Ctr Computat Sci, Lexington, KY 40506 USA. Fdn Res & Technol Hellas, Inst Elect Struct & Laser, Iraklion 71110, Crete, Greece. NASA, Ames Res Ctr, CSC, Moffett Field, CA 94035 USA. Russian Acad Sci, Inst Biochem Phys, Moscow 119991, Russia. RP Menon, M (reprint author), Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. EM super250@pop.uky.edu; andriot@iesl.forth.gr; deepak@nas.nasa.gov; iponomar@sky.chph.ras.ru; cherno@sky.chph.ras.ru RI Ponomareva, Inna/C-4067-2012; Andriotis, Antonios/A-2848-2014 NR 19 TC 40 Z9 41 U1 1 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 3 PY 2003 VL 91 IS 14 AR 145501 DI 10.1103/PhysRevLett.91.145501 PG 4 WC Physics, Multidisciplinary SC Physics GA 728LW UT WOS:000185719500024 PM 14611533 ER PT J AU Snyder, GJ Ursell, TS AF Snyder, GJ Ursell, TS TI Thermoelectric efficiency and compatibility SO PHYSICAL REVIEW LETTERS LA English DT Article ID GENERATORS; OPERATION AB The intensive reduced efficiency eta(r) is derived for thermoelectric power generation (in one dimension) from intensive fields and currents, giving eta(r)= E.J/-delT.J(S). The overall efficiency is derivable from a thermodynamic state function, Phi=1/u+alphaT, where we introduce u=J/kappadelT as the relative current density. The method simplifies the computation and clarifies the physics behind thermoelectric devices by revealing a new materials property s=(root1+zT-1)/(alphaT), which we call the compatibility factor. Materials with dissimilar compatibility factors cannot be combined by segmentation into an efficient thermoelectric generator because of constraints imposed on u. Thus, control of the compatibility factor s is, in addition to z, essential for efficient operation of a thermoelectric device, and thus will facilitate rational materials selection, device design, and the engineering of functionally graded materials. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Snyder, G. Jeffrey/E-4453-2011; Snyder, G/I-2263-2015 OI Snyder, G. Jeffrey/0000-0003-1414-8682; NR 15 TC 184 Z9 185 U1 9 U2 85 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD OCT 3 PY 2003 VL 91 IS 14 AR 148301 DI 10.1103/PhysRevLett.91.148301 PG 4 WC Physics, Multidisciplinary SC Physics GA 728LW UT WOS:000185719500052 PM 14611561 ER PT J AU Burton, SP Thomason, LW AF Burton, SP Thomason, LW TI Molecular density retrieval and temperature climatology for 40-60 km from SAGE II SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE SAGE II; stratopuse; temperature ID MIDDLE ATMOSPHERE; TIME-SERIES; LIDAR DATA; UPPER-STRATOSPHERE; TRENDS; VARIABILITY; ROCKETSONDE; PROFILES; UARS AB [1] The Stratospheric Aerosol and Gas Experiment (SAGE) II is a spaceborne solar occultation instrument that makes long-term stable measurements of atmospheric transmission at seven wavelengths between the ultraviolet and the near infrared. It provides near-global coverage ( from about 75 degreesS to 75 degreesN latitude) and a data record spanning over 18 years starting in late 1984. Recently, a self-consistent molecular density retrieval was developed which uses SAGE II version 6.10 transmission data above 40 km altitude. Since at this altitude attenuation of solar radiation due to aerosols can be neglected, there is enough independent information in five SAGE II channels ( 386 600 nm) to separate the absorption due to ozone and nitrogen dioxide from Rayleigh scattering. Vertical inversion to obtain profiles of these quantities from 40 to 60 km proceeds as in the standard SAGE II algorithm, using a matrix of refracted path lengths. The density gradient information for averaged profiles is converted to temperature. The data are sorted into 20degrees latitude bands from 70 degreesS to 70 degreesN latitude, and the time series are fitted to provide a mean climatology and long-term trend estimates. The climatology agrees well with published climatologies for the northern midlatitudes and includes results for the other latitude bands as well. Analysis of long-term variation finds no statistically significant effect from the solar cycle or quasi-biennial oscillation and no statistically significant trend. An upper bound on a possible cooling trend of 3 or 4 K/decade is derived for high and middle latitudes between 40 and 45 km altitude. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Sci Applicat Int Corp, Hampton, VA USA. RP Burton, SP (reprint author), NASA, Langley Res Ctr, Mail Stop 475, Hampton, VA 23681 USA. EM s.p.burton@larc.nasa.gov; l.w.thomason@nasa.gov NR 33 TC 2 Z9 2 U1 1 U2 6 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 2 PY 2003 VL 108 IS D19 AR 4593 DI 10.1029/2003JD003605 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 731NN UT WOS:000185892200005 ER PT J AU Anderson, JD Lau, EL Bird, MK Clark, BC Giampieri, G Patzold, M AF Anderson, JD Lau, EL Bird, MK Clark, BC Giampieri, G Patzold, M TI Dynamic science on the Stardust mission SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Wild 2; Stardust; radio science ID P-GRIGG-SKJELLERUP; INNER DUST COMA; GIOTTO SPACECRAFT; HALLEY; ENCOUNTER AB [1] Radio Doppler and ranging data at X band (similar to8.4 GHz), optical navigation data, and spacecraft attitude control data can be used to characterize the dust environment surrounding comet 81P/Wild 2 and possibly the mass and bulk density of its nucleus. As a secondary objective, a favorable solar conjunction prior to the cometary encounter on 2 January 2004 can be used to sound the Sun's corona at X band. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Bonn, Inst Radioastron, D-53121 Bonn, Germany. Lockheed Martin Astronaut Co, Denver, CO 80201 USA. Univ London Imperial Coll Sci Technol & Med, Dept Math, London SW7 2BW, England. Univ Cologne, Inst Geophys & Meteorol, D-50923 Cologne, Germany. RP Anderson, JD (reprint author), CALTECH, Jet Prop Lab, MS 238-420,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM john.d.anderson@jpl.nasa.gov NR 18 TC 5 Z9 6 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9097 EI 2169-9100 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD OCT 2 PY 2003 VL 108 IS E10 AR 8117 DI 10.1029/2003JE002092 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 731NX UT WOS:000185893000001 ER PT J AU Lind, R Voracek, DF Truax, R Doyle, T Potter, S Brenner, M AF Lind, R Voracek, DF Truax, R Doyle, T Potter, S Brenner, M TI A flight test to demonstrate flutter and evaluate the flutterometer SO AERONAUTICAL JOURNAL LA English DT Article ID TOOL AB A project was recently completed that investigated the ability to predict the onset of flutter using tools like the flutterometer. This project used an experiment called the aerostructures test wing that was flown while mounted to the flight test fixture on an F-15. Several flight tests were conducted to expand the envelope and determine he aeroelastic dynamics of the experiment. The final flight ended with destruction of the experiment due to the onset of flutter. The flutterometer attempted to predict this onset by analysing the flight data. The results indicate the flutterometer is able to generate a conservative estimate of the flight conditions associated with flutter. This paper details the flight tests of the experiment and the resulting predictions from the flutterometer. C1 Univ Florida, Dept Aerosp Engn, Gainesville, FL 32611 USA. NASA, Dryden Flight Res Ctr, Edwards AFB, CA USA. RP Lind, R (reprint author), Univ Florida, Dept Aerosp Engn, Gainesville, FL 32611 USA. NR 24 TC 11 Z9 11 U1 0 U2 0 PU ROYAL AERONAUTICAL SOC PI LONDON PA 4 HAMILTON PL, LONDON W1J 7BQ, ENGLAND SN 0001-9240 J9 AERONAUT J JI Aeronaut. J. PD OCT PY 2003 VL 107 IS 1076 BP 577 EP 588 PG 12 WC Engineering, Aerospace SC Engineering GA 737JA UT WOS:000186225600001 ER PT J AU Pack, LG Seifert, A AF Pack, LG Seifert, A TI Effects of sweep on the dynamics of active separation control SO AERONAUTICAL JOURNAL LA English DT Article ID HIGH REYNOLDS-NUMBERS; DIRECT NUMERICAL-SIMULATION; EXCITATION; FLOW AB A series of active flow control experiments were recently conducted at high Reynolds numbers on a wall mounted 'Hump'. The model simulates the upper surface of a 20% thick Glauert-Goldschmied type airfoil at zero incidence. The flow over the model is turbulent since the tunnel sidewall boundary-layer flows over it, eliminating laminar-turbulent transition from the problem. The main motivation for the experiments was to generate a comprehensive data base for validation of unsteady numerical simulation as a first step in the development of a design tool, without which it would not be possible to effectively utilise the great potential of unsteady flow control. This paper focuses on the dynamics of several key features of the baseline as well as the controlled two- and three-dimensional flows. It was found that the two-dimensional separated flow contains unsteady waves centered on a reduced frequency (Strouhal number based on the length of the separated region and free-stream velocity) of 0.8, while in the three-dimensional separated flow, reduced frequencies of 0.3 and 1.0 are active. Several scenarios of resonant wave interaction take place over the separated shear-layer and in the pressure recovery regions. The unstable reduced frequency bands for periodic excitation are centered on 1.5 and 5, but these reduced frequencies are based on the length of the baseline bubble that shortens due to the excitation. The conventional swept wing-scaling works well for the coherent wave features. Reproduction of these dynamic effects by a numerical simulation would provide benchmark validation. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. Tel Aviv Univ, Fac Engn, IL-69978 Tel Aviv, Israel. RP Pack, LG (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 12 TC 1 Z9 1 U1 1 U2 1 PU ROYAL AERONAUTICAL SOC PI LONDON PA 4 HAMILTON PL, LONDON W1J 7BQ, ENGLAND SN 0001-9240 J9 AERONAUT J JI Aeronaut. J. PD OCT PY 2003 VL 107 IS 1076 BP 617 EP 629 PG 13 WC Engineering, Aerospace SC Engineering GA 737JA UT WOS:000186225600005 ER PT J AU Bur, R Benay, R Chanetz, B Galli, A Pot, T Hollis, B Moss, J AF Bur, R Benay, R Chanetz, B Galli, A Pot, T Hollis, B Moss, J TI Experimental and numerical study of the Mars Pathfinder vehicle SO AEROSPACE SCIENCE AND TECHNOLOGY LA English DT Article DE hypersonic; shock wave; separation; heat flux; Navier-Stokes solver; DSMC code AB An experimental and numerical study on the Mars Pathfinder aeroshell vehicle has been carried out in the framework of an agreement between ONERA and NASA. The experimental work was performed in the ONERA R5Ch hypersonic wind tunnel. Flowfield visualizations and heat-flux measurements along the model have been obtained. Numerical simulations have been performed at ONERA with the Reynolds-Averaged Navier-Stokes (RANS) solver NASCA and at NASA with a Direct Simulation Monte Carlo (DSMC) code. The flowfield structure is correctly reproduced by both computations. The location of the bow shock is well predicted, as well as the expansion waves emanating from the end of the forebody cone. Both computations also predict the same extension of the separation bubble in the base flow region of the model. Measured and calculated heat-flux distributions along the model have been compared. Both computations give similar results, except for the prediction of the heat-flux level on the afterbody cone. But computations overpredict the measured heat-flux values on the forebody and the model sting: the value of the stagnation point is overestimated at 28% and the average sting level at 35%. (C) 2003 Editions scientiliques et medicales Elsevier SAS. All rights reserved. C1 Off Natl Etud & Rech Aerosp, Fundamental & Expt Aerodynam Dept, F-92322 Chatillon, France. NASA, Langley Res Ctr, Aerothermodynam Branch, Hampton, VA 23681 USA. RP Bur, R (reprint author), Off Natl Etud & Rech Aerosp, Fundamental & Expt Aerodynam Dept, BP 72,29 Ave Div Leclerc, F-92322 Chatillon, France. NR 12 TC 1 Z9 1 U1 2 U2 3 PU EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS PA 23 RUE LINOIS, 75724 PARIS, FRANCE SN 1270-9638 J9 AEROSP SCI TECHNOL JI Aerosp. Sci. Technol. PD OCT PY 2003 VL 7 IS 7 BP 510 EP 516 DI 10.1016/S1270-9638(03)00062-2 PG 7 WC Engineering, Aerospace SC Engineering GA 737NW UT WOS:000186239500002 ER PT J AU Harstad, KG Le Clercq, PC Bellan, J AF Harstad, KG Le Clercq, PC Bellan, J TI Statistical model of multicomponent-fuel drop evaporation for many-drop flow simulations SO AIAA JOURNAL LA English DT Article ID CONTINUOUS THERMODYNAMICS; CONTINUOUS MIXTURES; VAPORIZATION; COMBUSTION; DISTRIBUTIONS; COMPONENTS; EQUATION AB drop and in the gas phase surrounding it. When a complementary discrete-component model is used, it is shown that, when drops are immersed in a carrier gas containing fuel vapor, condensation of species onto the drop results in the development of a minor peak in the liquid composition probability distribution function (PDF). This peak leads to a PDF shape that can be viewed as a combination of two gamma PDFs, which is determined by five parameters. A model is developed for calculating the parameters of the two combined gamma PDFs. Extensive tests of the model for both diesel and gasoline show that the PDF results replicate accurately the discrete model predictions. Most important, the mean and variance of the composition at the drop surface are in excellent agreement with the discrete model. Results from the model show that although the second peak is minor for the liquid PDF, its corresponding peak for the vapor distribution at the drop surface has a comparable magnitude to and sometimes exceeds that corresponding to the first peak. Four-parameter models are also exercised, and it is shown that they are unable to capture the physics of the problem. C1 CALTECH, Jet Prop Lab, Thermal & Prop Engn Sect, Pasadena, CA 91109 USA. RP Harstad, KG (reprint author), CALTECH, Jet Prop Lab, Thermal & Prop Engn Sect, 4800 Oak Grove Dr,Mail Stop 125-109, Pasadena, CA 91109 USA. NR 33 TC 15 Z9 15 U1 3 U2 9 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD OCT PY 2003 VL 41 IS 10 BP 1858 EP 1874 DI 10.2514/2.1894 PG 17 WC Engineering, Aerospace SC Engineering GA 726RE UT WOS:000185612300002 ER PT J AU Yep, TW Agrawal, AK Griffin, D AF Yep, TW Agrawal, AK Griffin, D TI Gravitational effects on near-field flow structure of low-density gas jets SO AIAA JOURNAL LA English DT Article ID RAINBOW SCHLIEREN DEFLECTOMETRY; HELIUM JET; INSTABILITY; BEHAVIOR; AIR AB Experiments were conducted in Earth gravity and microgravity to acquire quantitative data on near-field How structure of helium jets injected into air. Microgravity conditions were simulated in the 2.2-s drop tower at NASA John H. Glenn Research Center. The jet How was observed by quantitative rainbow schlieren deflectometry, a nonintrusive line-of-sight measurement technique suited for the microgravity environment. The flow structure was characterized by distributions of helium mole fraction obtained from color schlieren images taken at 60 Hz. Results show that the jet in microgravity was up to 70% wider than that in Earth gravity. Experiments reveal that the global flow oscillations observed in Earth gravity are absent in microgravity. Quantitative details are provided of flow evolution as the experiment undergoes change in gravity in the drop tower. C1 Univ Oklahoma, Sch Aerosp & Mech Engn, Norman, OK 73019 USA. NASA, John H Glenn Res Ctr, Micrograv Sci Div, Cleveland, OH 44135 USA. RP Yep, TW (reprint author), Univ Oklahoma, Sch Aerosp & Mech Engn, Norman, OK 73019 USA. RI Agrawal, Ajay/B-5304-2010 NR 19 TC 10 Z9 11 U1 1 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 OCT PY 2003 VL 41 IS 10 BP 1973 EP 1979 DI 10.2514/2.1887 PG 7 WC Engineering, Aerospace SC Engineering GA 726RE UT WOS:000185612300013 ER PT J AU Sobieszczanski-Sobieski, J Altus, TD Phillips, M Sandusky, R AF Sobieszczanski-Sobieski, J Altus, TD Phillips, M Sandusky, R TI Bilevel integrated system synthesis for concurrent and distributed processing SO AIAA JOURNAL LA English DT Article ID OPTIMIZATION; CONSTRAINTS AB A new version is introduced of the bilevel integrated system synthesis method intended for optimization of engineering systems conducted by distributed specialty groups working concurrently in a multiprocessor computing environment. The method decomposes the overall optimization task into subtasks associated with disciplines or subsystems, where the local design variables are numerous and a single, system-level optimization whose design variables are relatively few. The subtasks are fully autonomous as to their inner operations and decision making. Their purpose is to eliminate the local design variables and generate a wide spectrum of feasible designs whose behavior is represented by response surfaces to be accessed by a system-level optimization. It is shown that, if the problem is convex, the solution of the decomposed problem is the same as that obtained without decomposition. A simplified example of an aircraft design shows the method working as intended. A discussion of the method merits and demerits as well as recommendations for further research is included. C1 NASA, Langley Res Ctr, Analyt & Computat Methods Branch, Hampton, VA 23681 USA. George Washington Univ, Hampton, VA 23681 USA. RP Sobieszczanski-Sobieski, J (reprint author), NASA, Langley Res Ctr, Analyt & Computat Methods Branch, Mail Stop 240, Hampton, VA 23681 USA. NR 36 TC 51 Z9 53 U1 0 U2 2 PU AMER INST AERONAUTICS ASTRONAUTICS PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 EI 1533-385X J9 AIAA J JI AIAA J. PD OCT PY 2003 VL 41 IS 10 BP 1996 EP 2003 DI 10.2514/2.1889 PG 8 WC Engineering, Aerospace SC Engineering GA 726RE UT WOS:000185612300016 ER PT J AU Qu, XY Haftka, RT Venkataraman, S Johnson, TF AF Qu, XY Haftka, RT Venkataraman, S Johnson, TF TI Deterministic and reliability-based optimization of composite laminates for cryogenic environments SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 42nd Structures, Structural Dynamics, and Materials Conference CY APR 16-19, 2001 CL SEATTLE, WA SP Amer Inst Aeronaut & Astronaut, ASME, ASCE, AHS, ASC ID DAMAGE AB Designs of composite laminates are investigated for hydrogen tanks in cryogenic environments. Large residual strains, which can develop due to thermal mismatch between matrix and fibers, result in matrix cracking at cryogenic temperatures and increase hydrogen leakage through the tank wall. To reduce thermal mismatch, ply angles need to be close to each other, but this leads to a substantial weight increase under biaxial loading. First deterministic optimization is used to investigate possible weight reduction measures. Reducing axial loads on walls by auxiliary stiffening mechanisms led to significant weight reduction. Reliability-based optimizations were performed to identify the uncertainties in composite material properties with the largest influences on the optimum design. Then measures for reducing uncertainty in important parameters are examined. The results indicate that the most effective measure for reducing thickness is quality control. 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, Mech & Durabil Branch, Hampton, VA 23681 USA. RP Qu, XY (reprint author), Univ Florida, Dept Mech & Aerosp Engn, POB 116250, Gainesville, FL 32611 USA. EM xueyong@mae.ufl.edu; haftka@ufl.edu; satchi@engineering.sdsu.edu NR 13 TC 35 Z9 35 U1 2 U2 5 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD OCT PY 2003 VL 41 IS 10 BP 2029 EP 2036 DI 10.2514/2.1893 PG 8 WC Engineering, Aerospace SC Engineering GA 726RE UT WOS:000185612300020 ER PT J AU Johnson, JR Horz, F Staid, MI AF Johnson, JR Horz, F Staid, MI TI Thermal infrared spectroscopy and modeling of experimentally shocked plagioclase feldspars SO AMERICAN MINERALOGIST LA English DT Article ID EMISSION SPECTROMETER; REFLECTANCE SPECTRA; MU-M; RAMAN-SPECTROSCOPY; DIAPLECTIC GLASS; ANORTHITE; IMPACT; MARS; AMORPHIZATION; TERRESTRIAL AB Thermal infrared emission and reflectance spectra (250-1400 cm(-1); similar to7-40 mum) of experimentally shocked albite- and anorthite-rich rocks (17-56 GPa) demonstrate that plagioclase feldspars exhibit characteristic degradations in spectral features with increasing pressure. New measurements of albite (Ab(98)) presented here display major spectral absorptions between 1000-1250 cm(-1) (8-10 mmu) (due to Si-O antisymmetric stretch motions of the silica tetrahedra) and weaker absorptions between 350-700 cm(-1) (14-29 mum) (due to Si-O-Si octahedral bending vibrations). Many of these features persist to higher pressures compared to similar features in measurements of shocked anorthite, consistent with previous thermal infrared absorption studies of shocked feldspars. A transparency feature at 855 cm(-1) (11.7 mum) observed in powdered albite spectra also degrades with increasing pressure, similar to the 830 cm(-1) (12.0 mum) transparency feature in spectra of powders of shocked anorthite. Linear deconvolution models demonstrate that combinations of common mineral and glass spectra can replicate the spectra of shocked anorthite relatively well until shock pressures of 20-25 GPa, above which model errors increase substantially, coincident with the onset of diaplectic glass formation. Albite deconvolutions exhibit higher errors overall but do not change significantly with pressure, likely because certain clay minerals selected by the model exhibit absorption features similar to those in highly shocked albite. The implication for deconvolution of thermal infrared spectra of planetary surfaces (or laboratory spectra of samples) is that the use of highly shocked anorthite spectra in end-member libraries could be helpful in identifying highly shocked calcic plagioclase feldspars. C1 US Geol Survey, Flagstaff, AZ 86001 USA. NASA, Johnson Space Ctr, Houston, TX 77058 USA. RP Johnson, JR (reprint author), US Geol Survey, 2255 N Gemini Dr, Flagstaff, AZ 86001 USA. RI Johnson, Jeffrey/F-3972-2015 NR 60 TC 26 Z9 26 U1 0 U2 5 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD OCT PY 2003 VL 88 IS 10 BP 1575 EP 1582 PG 8 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 731PK UT WOS:000185895500021 ER PT J AU Leventis, N Oh, WS Gao, XR Rawashdeh, AMM AF Leventis, N Oh, WS Gao, XR Rawashdeh, AMM TI Nonadditive voltammetric currents from two redox-active substances and electroanalytical implications SO ANALYTICAL CHEMISTRY LA English DT Article ID POTENTIAL STEP CHRONOAMPEROMETRY; ELECTRON-TRANSFER; CONCENTRATION PROFILES; DIFFUSIONAL PATHWAYS; MICROSCOPY; TRANSFERS; KINETICS AB At the potential range where both decamethylferrocene (dMeFc). and ferrocene (Fc) are oxidized with rates controlled by linear diffusion, electrogenerated Fc(.+) radicals diffusing outward from the electrode react quantitatively (K-23degreesC = 5.8 x 10(8)) with dMeFc diffusing toward the electrode and produce Fc and dMeFc(.+). That reaction replaces dMeFc with Fc, whose diffusion coefficient is higher than that of dMeFc, and the total mass-transfer limited current from the mixture is increased by similar to10%. Analogous observations are made when mass transfer is controlled by convective diffusion as in RDE voltammetry. Similar results have been obtained with another, and for all practical purposes randomly selected pair of redox-active substances, [Co(bipy)(3)](2+) and N-methylphenothiazine (MePTZ); reaction of MePTZ(.+) with [Co(bipy)(3)](2+) replaces the latter with MePTZ, which diffuses faster, and the total current increases by similar to20%. The experimental voltammograms have been simulated numerically and the role of (a) the rate constant of the homogeneous reaction, (b) the relative concentrations, and (c) the diffusion coefficients of all species involved have been studied in detail. Importantly, it was also identified that within any given redox system the dependence of the mass-transfer limited current on the bulk concentrations of the redox-active species is expected to be nonlinear. These findings are discussed in terms of their electroanalytical implications. C1 Univ Missouri, Dept Chem, Rolla, MO 65409 USA. RP Leventis, N (reprint author), NASA, Glenn Res Ctr, Div Mat, 21000 Brookpk Rd,MS 49-1, Cleveland, OH 44135 USA. NR 25 TC 9 Z9 9 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD OCT 1 PY 2003 VL 75 IS 19 BP 4996 EP 5005 DI 10.1021/ac030176u PG 10 WC Chemistry, Analytical SC Chemistry GA 728LB UT WOS:000185717700013 ER PT J AU Bogdanov, AT Glassmeier, KH Musmann, G Dougherty, MK Kellock, S Slootweg, P Tsurutani, B AF Bogdanov, AT Glassmeier, KH Musmann, G Dougherty, MK Kellock, S Slootweg, P Tsurutani, B TI Ion cyclotron waves in the Earth's magnetotail during CASSINI's Earth swing-by SO ANNALES GEOPHYSICAE LA English DT Article DE space plasma physics; waves and instabilities; magnetospheric physics; plasma waves and instabilities; magnetotail ID PLASMA SHEET BOUNDARY; LOW-FREQUENCY WAVES; ANISOTROPY INSTABILITY; BEAM INSTABILITIES; ISEE OBSERVATIONS; LAYER; MAGNETOSHEATH; CONSEQUENCES; PROPAGATION; GENERATION AB The properties of low frequency magnetotail waves observed during CASSINI's Earth swing-by are examined. A maximum in the distribution of the waves about half the proton cyclotron frequency and a peak at linear polarisation are found and their implications are analysed in detail. Data on the fluid plasma velocity for the observation interval are not available and thus no unique conclusions about Doppler shift influence on the properties of the waves can be made. This determines the need to analyse different hypotheses in order to understand the origin of the waves. The plausibility of competing interpretations, such as off-resonance proton cyclotron waves and bi-ion cyclotron waves at the gyrofrequency of a heavy ion component of the magnetotail plasma in the form of He++ ions of solar wind origin is questioned. C1 Tech Univ Braunschweig, Inst Geophys & Meteorol, D-38106 Braunschweig, Germany. Univ London Imperial Coll Sci Technol & Med, London, England. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Bogdanov, AT (reprint author), Tech Univ Braunschweig, Inst Geophys & Meteorol, Mendelssohnstr 3, D-38106 Braunschweig, Germany. EM a.bogdanov@tu-bs.de RI Slootweg, P.J./H-8089-2014 NR 42 TC 5 Z9 5 U1 1 U2 1 PU COPERNICUS GESELLSCHAFT MBH PI GOTTINGEN PA BAHNHOFSALLEE 1E, GOTTINGEN, 37081, GERMANY SN 0992-7689 J9 ANN GEOPHYS-GERMANY JI Ann. Geophys. PD OCT PY 2003 VL 21 IS 10 BP 2043 EP 2057 PG 15 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 775NL UT WOS:000189047500002 ER PT J AU Randriambelo, T Baray, JL Baldy, S Thompson, AM Oltmans, S Keckhut, P AF Randriambelo, T Baray, JL Baldy, S Thompson, AM Oltmans, S Keckhut, P TI Investigation of the short-time variability of tropical tropospheric ozone SO ANNALES GEOPHYSICAE LA English DT Article DE atmospheric composition and structure; troposphere-composition and chemistry; meteorology and atmospheric dynamics climatology; tropical meteorology ID INDIAN-OCEAN; SOUTHERN AFRICA; TRACE-A; METEOROLOGICAL CONDITIONS; VERTICAL-DISTRIBUTION; FIELD OBSERVATIONS; TRANSPORT; CLIMATOLOGY; STRATOSPHERE; SUBTROPICS AB Since 1998, a ground-based tropospheric ozone lidar has been running at Reunion Island and has been involved with a daily measurement campaign that was performed in the latter part of the biomass burning season, during November-December 1999. The averaged ozone profile obtained during November-December 1999 agrees well with the averaged ozone profile obtained from the ozonesondes launch at Reunion during November-December (19922001). Comparing weekly sonde launches (part of the Southern Hemisphere Additional Ozonesondes: SHADOZ program) with the daily ground-based lidar observations shows that some striking features of the day-to-day variability profiles are not observed in the sonde measurements. Ozone profiles respond to the nature of disturbances which vary from one day to the next. The vertical ozone distribution at Reunion is examined as a function of prevailing atmospheric circulation. Back trajectories show that most of the enhanced ozone crossed over biomass burning and convectively active regions in Madagascar and the southern African continent. The analyses of the meteorological data show that ozone stratification profiles are in agreement with the movement of the synoptic situations in November-December 1999. Three different sequences of transport are explained using wind fields. The first sequence from 23 to 25 November is characterized by northerly transport; during the second sequence from 26 to 30 November, the air masses are influenced by meridional transport. The third sequence from 2 to 6 December is characterized by westerly transport associated with the subtropical jet stream. The large, standard deviations of lidar profiles in the middle and upper troposphere are in agreement with the upper wind variabilities which evidence passing ridge and trough disturbances. During the transition period between the dry season and the wet season, multiple ozone sources including stratosphere-troposphere exchanges, convection and biomass burning contribute to tropospheric ozone at Reunion Island through sporadic events characterized by a large spatial and temporal variability. C1 CNRS, Lab Phys Atmosphere, UMR 8105, F-97715 Reunion Isl, France. NASA, Goddard Space Flight Ctr, Goddard Lab Atmosphere, Greenbelt, MD 20771 USA. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. Serv Aeron, F-91371 Verrieres Le Buisson, Paris, France. RP Randriambelo, T (reprint author), CNRS, Lab Phys Atmosphere, UMR 8105, 15 Ave Rene Cassin, F-97715 Reunion Isl, France. EM randriam@univ-reunion.fr RI Thompson, Anne /C-3649-2014 OI Thompson, Anne /0000-0002-7829-0920 NR 36 TC 9 Z9 9 U1 0 U2 2 PU COPERNICUS GESELLSCHAFT MBH PI GOTTINGEN PA BAHNHOFSALLEE 1E, GOTTINGEN, 37081, GERMANY SN 0992-7689 EI 1432-0576 J9 ANN GEOPHYS-GERMANY JI Ann. Geophys. PD OCT PY 2003 VL 21 IS 10 BP 2095 EP 2106 PG 12 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA 775NL UT WOS:000189047500006 ER PT J AU Hirshon, JM Weiss, SR LoCasale, R Levine, E Blaisdell, CJ AF Hirshon, JM Weiss, SR LoCasale, R Levine, E Blaisdell, CJ TI Looking beyond urban and rural differences: Emergency department use by asthmatic children SO ANNALS OF EMERGENCY MEDICINE LA English DT Meeting Abstract CT Research Forum of the American-College-of-Emergency-Physicians CY OCT 12-13, 2003 CL BOSTON, MASSACHUSETTS SP Amer Coll Emergency Physicians C1 Univ Maryland, Baltimore, MD 21201 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MOSBY, INC PI ST LOUIS PA 11830 WESTLINE INDUSTRIAL DR, ST LOUIS, MO 63146-3318 USA SN 0196-0644 J9 ANN EMERG MED JI Ann. Emerg. Med. PD OCT PY 2003 VL 42 IS 4 SU S MA 400 BP S109 EP S109 PG 1 WC Emergency Medicine SC Emergency Medicine GA 730JT UT WOS:000185828200392 ER PT J AU Huang, NE Wu, ML Qu, WD Long, SR Shen, SSP Zhang, JE AF Huang, NE Wu, ML Qu, WD Long, SR Shen, SSP Zhang, JE TI Applications of Hilbert-Huang transform to non-stationary financial time series analysis (vol 19, pg 245, 2003) SO APPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY LA English DT Correction C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. CALTECH, Pasadena, CA 91125 USA. NASA, Wallops Flight Facil, Lab Hydrospher Proc, Wallops Isl, VA 23337 USA. Univ Alberta, Dept Math Sci, Edmonton, AB T6G 2G1, Canada. Hong Kong Univ Sci & Technol, Dept Finance, Kowloon, Hong Kong, Peoples R China. RP Huang, NE (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Code 971, Greenbelt, MD 20771 USA. RI Long, Steven/D-7248-2012 NR 1 TC 1 Z9 1 U1 1 U2 11 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1524-1904 J9 APPL STOCH MODEL BUS JI Appl. Stoch. Models. Bus. Ind. PD OCT-DEC PY 2003 VL 19 IS 4 BP 361 EP 361 DI 10.1002/asmb.506 PG 1 WC Operations Research & Management Science; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Operations Research & Management Science; Mathematics GA 754PH UT WOS:000187326100007 ER PT J AU Sanders, DB Mazzarella, JM Kim, DC Surace, JA Soifer, BT AF Sanders, DB Mazzarella, JM Kim, DC Surace, JA Soifer, BT TI The IRAS revised bright galaxy sample SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : general; infrared radiation ID VELOCITY-WIDTH RELATION; TELESCOPE KEY PROJECT; LUMINOSITY FUNCTION; DISTANCE SCALE; LOCAL SUPERCLUSTER; INFRARED GALAXIES; NEARBY GALAXIES; HUBBLE CONSTANT; VIRGO CLUSTER; RADIO-SOURCES AB IRAS flux densities, redshifts, and infrared luminosities are reported for all sources identified in the IRAS Revised Bright Galaxy Sample (RBGS), a complete flux-limited survey of all extragalactic objects with total 60 mum flux density greater than 5.24 Jy, covering the entire sky surveyed by IRAS at Galactic latitudes \b\ > 5degrees. The RBGS includes 629 objects, with median and mean sample redshifts of 0.0082 and 0.0126, respectively, and a maximum redshift of 0.0876. The RBGS supersedes the previous two-part IRAS Bright Galaxy Samples (BGS(1)+BGS(2)), which were compiled before the final (Pass 3) calibration of the IRAS Level 1 Archive in 1990 May. The RBGS also makes use of more accurate and consistent automated methods to measure the flux of objects with extended emission. The RBGS contains 39 objects that were not present in the BGS(1)+BGS(2), and 28 objects from the BGS(1)+BGS(2) have been dropped from RBGS because their revised 60 mum flux densities are not greater than 5.24 Jy. Comparison of revised flux measurements for sources in both surveys shows that most flux differences are in the range similar to5%-25%, although some faint sources at 12 and 25 mum differ by as much as a factor of 2. Basic properties of the RBGS sources are summarized, including estimated total infrared luminosities, as well as updates to cross identifications with sources from optical galaxy catalogs established using the NASA/IPAC Extragalactic Database. In addition, an atlas of images from the Digitized Sky Survey with overlays of the IRAS position uncertainty ellipse and annotated scale bars is provided for ease in visualizing the optical morphology in context with the angular and metric size of each object. The revised bolometric infrared luminosity function, phi(L-ir), for infrared-bright galaxies in the local universe remains best fit by a double power law, phi(L) proportional to L-alpha, with alpha = -0.6(+/-0.1) and alpha = -2.2(+/-0.1) below and above the "characteristic" infrared luminosity L-ir* similar to 10(10.5) Lcircle dot, respectively. A companion paper provides IRAS High Resolution (HIRES) processing of over 100 RBGS sources where improved spatial resolution often provides better IRAS source positions or allows for deconvolution of close galaxy pairs. C1 Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. CALTECH, Jet Prop Lab, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. CALTECH, SIRTF Sci Ctr, Pasadena, CA 91125 USA. CALTECH, Div Phys Math & Astron, Downes Lab, Pasadena, CA 91125 USA. RP Sanders, DB (reprint author), Univ Hawaii, Inst Astron, 2680 Woodlawn Dr, Honolulu, HI 96822 USA. OI Mazzarella, Joseph/0000-0002-8204-8619 NR 33 TC 606 Z9 606 U1 1 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 2003 VL 126 IS 4 BP 1607 EP 1664 DI 10.1086/376841 PG 58 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TM UT WOS:000185676200001 ER PT J AU Crenshaw, DM Kraemer, SB Gabel, JR AF Crenshaw, DM Kraemer, SB Gabel, JR TI The host galaxies of narrow-line Seyfert 1 galaxies: Evidence for bar-driven fueling SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : Seyfert ID ACTIVE GALACTIC NUCLEI; SUPERMASSIVE BLACK-HOLES; H-ALPHA EMISSION; X-RAY; IMAGING SURVEY; VARIABILITY; ATLAS; ENVIRONMENT; MORPHOLOGY; EVOLUTION AB We present a study of the host galaxy morphologies of narrow- and broad-line Seyfert 1 galaxies (NLS1's and BLS1's) based on broadband optical images from the Hubble Space Telescope archives. We find that large-scale stellar bars, starting at similar to1 kpc from the nucleus, are much more common in NLS1's than BLS1's. Furthermore, the fraction of NLS1 spirals that have bars increases with decreasing full width at half-maximum of the broad component of Hbeta. These results suggest a link between the large-scale bars, which can support high fueling rates to the inner kiloparsecs, and the high mass accretion rates associated with the supermassive black holes in NLS1's. C1 Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. Catholic Univ Amer, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Crenshaw, DM (reprint author), Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30303 USA. NR 65 TC 66 Z9 66 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 OCT PY 2003 VL 126 IS 4 BP 1690 EP 1698 DI 10.1086/377625 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TM UT WOS:000185676200004 ER PT J AU Evans, A Gehrz, RD Geballe, TR Woodward, CE Salama, A Sanchez, RA Starrfield, SG Krautter, J Barlow, M Lyke, JE Hayward, TL Eyres, SPS Greenhouse, MA Hjellming, RM Wagner, RM Pequignot, D AF Evans, A Gehrz, RD Geballe, TR Woodward, CE Salama, A Sanchez, RA Starrfield, SG Krautter, J Barlow, M Lyke, JE Hayward, TL Eyres, SPS Greenhouse, MA Hjellming, RM Wagner, RM Pequignot, D TI Infrared Space Observatory and ground-based infrared observations of the classical nova V723 Cassiopeiae SO ASTRONOMICAL JOURNAL LA English DT Article DE circumstellar matter; novae, cataclysmic variables; stars : individual (Nova Cassiopeia 1995=V723 Cassiopeiae) ID SHORT-WAVELENGTH SPECTROMETER; NOVA V1974 CYGNI; ISO OBSERVATIONS; RADIO-EMISSION; IRON PROJECT; ATOMIC DATA; SPECTROSCOPY; IONS; EXCITATION; EVOLUTION AB We present observations of the classical nova V723 Cassiopeiae (Nova Cas 1995), obtained both with the Infrared Space Observatory (ISO) and from the ground. The infrared spectrum was dominated in the first year by H and He recombination lines, and at later times by coronal lines. The H recombination lines imply a reddening of E(B-V) = 0.78, an electron temperature of 7000 K, and an electron density of 2 x 10(8) cm(-3) on day 250. We argue that the high-ionization species in the infrared are most likely the result of collisional ionization rather than photoionization and are therefore truly "coronal''; we estimate a temperature of 3.2 x 10(5) K in the coronal region and abundance ratios of S/Si similar or equal to 2.1, Ca/Si similar or equal to 1.6, and Al/Si similar or equal to 1.5. The ejected mass as determined from the Bralpha line was 2.6 x 10(-5) M. for a distance of 4 kpc; however, the mass deduced from the free-free emission, which we conclude arises primarily in the coronal zone, is 4.3 x 10(-4) M.. V723 Cas did not display the [O IV] 25.89 mum fine-structure line, which was typically seen in the spectra of novae observed with ISO. There was no evidence of dust emission in V723 Cas. C1 Univ Keele, Sch Chem & Phys, Astrophys Grp, Keele ST5 5BG, Staffs, England. Univ Minnesota, Sch Phys & Astron, Dept Astron, Minneapolis, MN 55455 USA. Gemini Observ, Hilo, HI 96720 USA. ISO Data Ctr, ESA Satellite Tracking Stn, E-28080 Madrid, Spain. Univ Complutense, Fac CC Matemat, CSIC, Inst Astron & Geodesia, E-28040 Madrid, Spain. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Landessternwarte Konigstuhl, D-69117 Heidelberg, Germany. UCL, Dept Phys & Astron, London WC1E 6BT, England. Univ Cent Lancashire, Ctr Astrophys, Preston PR1 2HE, Lancs, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Arizona, Large Binocular Telescope Observ, Tucson, AZ 85721 USA. Observ Paris, F-92195 Meudon, France. RP Evans, A (reprint author), Univ Keele, Sch Chem & Phys, Astrophys Grp, Keele ST5 5BG, Staffs, England. RI Barlow, Michael/A-5638-2009 OI Barlow, Michael/0000-0002-3875-1171 NR 69 TC 22 Z9 22 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 2003 VL 126 IS 4 BP 1981 EP 1995 DI 10.1086/377618 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TM UT WOS:000185676200028 ER PT J AU Andersson, BG Idzi, R Uomoto, A Wannier, PG Chen, B Jorgensen, AM AF Andersson, BG Idzi, R Uomoto, A Wannier, PG Chen, B Jorgensen, AM TI A spectroscopic and photometric survey of stars in the field of L1457: A new distance determination (vol 124, pg 2164,2002) SO ASTRONOMICAL JOURNAL LA English DT Correction C1 Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Andersson, BG (reprint author), Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 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 0004-6256 J9 ASTRON J JI Astron. J. PD OCT PY 2003 VL 126 IS 4 BP 2087 EP 2087 DI 10.1086/378167 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TM UT WOS:000185676200036 ER PT J AU Palmeri, P Mendoza, C Kallman, TR Bautista, MA Melendez, M AF Palmeri, P Mendoza, C Kallman, TR Bautista, MA Melendez, M TI Modeling of iron K lines: Radiative and auger decay data for FeII-FeIX SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE atomic data; atomic processes; techniques : spectroscopic ID X-RAY-EMISSION; TRANSITION-PROBABILITY RATIOS; EQUAL-TO 32; FLUORESCENCE YIELDS; INTENSITY RATIOS; VACANCY STATES; ELEMENTS; SPECTRA; RATES; IONIZATION AB A detailed analysis of the radiative and Auger de-excitation channels of K- shell vacancy states in Fe II - Fe IX has been carried out. Level energies, wavelengths, A-values, Auger rates and fluorescence yields have been calculated for the lowest fine-structure levels populated by photoionization of the ground state of the parent ion. Different branching ratios, namely Kalpha(2) /Kalpha(1), Kbeta/ Kalpha, KLM /KLL, KMM /KLL, and the total K-shell fluorescence yields, omega(K), obtained in the present work have been compared with other theoretical data and solid-state measurements, finding good general agreement with the latter. The Kalpha(2) /Kalpha(1) ratio is found to be sensitive to the excitation mechanism. From these comparisons it has been possible to estimate an accuracy of similar to 10% for the present transition probabilities. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Venezolano Invest Cient, Ctr Fis, Caracas 1020A, Venezuela. RP Kallman, TR (reprint author), NASA, Goddard Space Flight Ctr, Code 662, Greenbelt, MD 20771 USA. NR 37 TC 82 Z9 82 U1 0 U2 4 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2003 VL 410 IS 1 BP 359 EP 364 DI 10.1051/0004-6361:20031262 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 728FY UT WOS:000185708200034 ER PT J AU Gorosabel, J Klose, S Christensen, L Fynbo, JPU Hjorth, J Greiner, J Tanvir, N Jensen, BL Pedersen, H Holland, ST Lund, N Jaunsen, AO Ceron, JMC Castro-Tirado, AJ Fruchter, A Pian, E Vreeswijk, PM Burud, I Frontera, F Kaper, L Kouveliotou, C Masetti, N Palazzi, E Rhoads, J Rol, E Salamanca, I Wijers, RAMJ van den Heuvel, E AF Gorosabel, J Klose, S Christensen, L Fynbo, JPU Hjorth, J Greiner, J Tanvir, N Jensen, BL Pedersen, H Holland, ST Lund, N Jaunsen, AO Ceron, JMC Castro-Tirado, AJ Fruchter, A Pian, E Vreeswijk, PM Burud, I Frontera, F Kaper, L Kouveliotou, C Masetti, N Palazzi, E Rhoads, J Rol, E Salamanca, I Wijers, RAMJ van den Heuvel, E TI The blue host galaxy of the red GRB 000418 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma rays : bursts; galaxies : fundamental parameters; techniques : photometric ID GAMMA-RAY BURSTS; LUMINOUS INFRARED GALAXIES; STAR-FORMING GALAXIES; INTERSTELLAR EXTINCTION; OPTICAL AFTERGLOW; MAGELLANIC CLOUD; STANDARD STARS; EMISSION; CONNECTION; EVOLUTION AB We report on multi-band (UBVRIZJ(s)K(s)) observations of the host galaxy of the April 18, 2000 gamma-ray burst. The Spectral Energy Distribution (SED) is analysed by fitting empirical and synthetic spectral templates. We find that: (i) the best SED fit is obtained with a starburst template, (ii) the photometric redshift is consistent with the spectroscopic redshift, (iii) the colours of the host are inconsistent with an old stellar population, and (iv) the global extinction is constrained to be in the range A(V) = 0.12-0.61 mag. The derived global extinction agrees with the one reported for the afterglow (A(V) = 0.4-0.9 mag), suggesting a homogeneous distribution of the interstellar medium (ISM) in the host galaxy. These findings are supplemented by morphological information from Hubble Space Telescope (HST) imaging: the surface brightness profile is smooth, symmetric and compact with no underlying structures (like dust lanes, spiral arms or disks). A natural scenario which accounts of all the above results is a nuclear starburst that harbours a young population of stars from which the GRB originated. C1 CSIC, Inst Astrofis Andalucia, E-18080 Granada, Spain. Danish Space Res Inst, DK-2100 Copenhagen O, Denmark. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Thuringer Landessternwarte Tautenberg, D-07778 Tautenburg, Germany. Inst Astrophys, D-14482 Potsdam, Germany. Aarhus Univ, Dept Phys & Astron, DK-8000 Aarhus C, Denmark. Univ Copenhagen, Astron Observ, DK-2100 Copenhagen O, Denmark. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. Univ Hertfordshire, Dept Phys Sci, Hatfield AL10 9AB, Herts, England. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. European So Observ, Santiago 19, Chile. Real Inst & Observ Armadda, Secc Astron, Cadiz, Spain. Osserv Astron Trieste, I-34131 Trieste, Italy. Univ Ferrara, Dipartmento Fis, I-44100 Ferrara, Italy. CNR, Ist Tecnol & Studio Radiaz Extraterr, I-40129 Bologna, Italy. Univ Amsterdam, NL-1098 SJ Amsterdam, Netherlands. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Gorosabel, J (reprint author), CSIC, Inst Astrofis Andalucia, POB 03004, E-18080 Granada, Spain. RI Fynbo, Johan/L-8496-2014; Christensen, Lise/M-5301-2014; Hjorth, Jens/M-5787-2014; Jensen, Brian Lindgren/E-1275-2015; Palazzi, Eliana/N-4746-2015; OI Fynbo, Johan/0000-0002-8149-8298; Pian, Elena/0000-0001-8646-4858; Christensen, Lise/0000-0001-8415-7547; Hjorth, Jens/0000-0002-4571-2306; Jensen, Brian Lindgren/0000-0002-0906-9771; Wijers, Ralph/0000-0002-3101-1808; Palazzi, Eliana/0000-0002-8691-7666; Castro-Tirado, A. J./0000-0003-2999-3563; Masetti, Nicola/0000-0001-9487-7740 NR 53 TC 39 Z9 39 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2003 VL 409 IS 1 BP 123 EP 133 DI 10.1051/0004-6361:20031047 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 721LQ UT WOS:000185318200012 ER PT J AU Klein, KL Schwartz, RA McTiernan, JM Trottet, G Klassen, A Lecacheux, A AF Klein, KL Schwartz, RA McTiernan, JM Trottet, G Klassen, A Lecacheux, A TI An upper limit of the number and energy of electrons accelerated at an extended coronal shock wave SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE shock waves; Sun : flares; Sun : particle emission; Sun : radio radiation; X rays : general ID II RADIO-BURST; X-RAY EVENTS; SOLAR-FLARES; PARTICLE-ACCELERATION; MASS EJECTIONS; EMISSION; ASSOCIATION; SPACECRAFT; RELEASE; BEAMS AB Type II radio emission is the most direct signature of extended shock waves in the solar corona, and a prime example of electron acceleration at a shock. Yet, the energetics of these electrons is poorly known. On 1996 August 19 and 1997 October 07 type II bursts were observed in association with flares behind the solar limb. While Earth-orbiting X-ray detectors aboard GOES and the Compton Gamma-Ray Observatory did not register emission above background, the Ulysses spacecraft, which had the candidate active region in its field of view, saw a major burst during the 1996 event. We use this peculiar configuration to infer the energetics of electrons accelerated in the low corona from the Ulysses observations, and to derive upper limits of the number and energy content of shock-accelerated electrons from the thresholds of the Earth-orbiting detectors. The inferred upper limit is similar to electron numbers estimated for large particle events at 1 AU, but the fluxes and energy fluxes of shock-accelerated electrons are much smaller than those required to produce a conspicuous hard X-ray burst. C1 Observ Paris, Sect Meudon, LESIA, CNRS,UMR 8109, F-92195 Meudon, France. NASA, Goddard Space Flight Ctr, SSAI, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Astrophys Inst Potsdam, Observ Solare Radioastron, D-14482 Potsdam, Germany. RP Klein, KL (reprint author), Observ Paris, Sect Meudon, LESIA, CNRS,UMR 8109, F-92195 Meudon, France. NR 54 TC 14 Z9 14 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2003 VL 409 IS 1 BP 317 EP 324 DI 10.1051/0004-6361:20031034 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 721LQ UT WOS:000185318200029 ER PT J AU Pottasch, SR Bernard-Salas, J Beintema, DA Feibelman, WA AF Pottasch, SR Bernard-Salas, J Beintema, DA Feibelman, WA TI Abundances of planetary nebulae NGC40 and NGC6153 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ISM : abundances; planetary nebulae : individual : NGC40, NGC6153; infrared : ISM; ISM : lines and bands ID 4.85 GHZ; LOW EXCITATION; O-VI; LINES; CATALOG; NGC-40; SPECTRUM; PHOTOMETRY; FLUXES; NUCLEI AB The ISO and IUE spectra of the elliptical nebulae NGC40 and NGC6153 are presented. These spectra are combined with the spectra in the visual wavelength region to obtain a complete, extinction corrected, spectrum. The chemical composition of the nebulae is then calculated and compared to previous determinations. A discussion is given of: ( 1) the recombination line abundances, (2) the exciting stars of the nebulae, and (3) possible evolutionary effects. C1 Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. SRON, Space Res Lab, NL-9700 AV Groningen, Netherlands. NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Pottasch, SR (reprint author), Kapteyn Astron Inst, POB 800, NL-9700 AV Groningen, Netherlands. NR 44 TC 19 Z9 19 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD OCT PY 2003 VL 409 IS 2 BP 599 EP 609 DI 10.1051/0004-6361:20031122 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 725FW UT WOS:000185534000025 ER PT J AU in 't Zand, JJM Strohmayer, TE Markwardt, CB Swank, J AF in 't Zand, JJM Strohmayer, TE Markwardt, CB Swank, J TI A peculiar type-I X-ray burst from GRS 1747-312 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE accretion, accretion disks; globular clusters : individual : Terzan 6; X-rays : binaries; X-rays : bursts; X-rays : individuals : GRS 1747-312 ID PHOTOSPHERIC RADIUS EXPANSION; GLOBULAR-CLUSTERS; NEUTRON STARS; DISCOVERY; PRECURSORS; BINARY; M15 AB We report the serendipitous detection with the Rossi X-ray Timing Explorer of a long and peculiar X-ray burst whose position is consistent with one known X-ray burster (GRS 1747-312) and which occurred when that source was otherwise quiescent. The peculiar feature concerns a strong radius expansion of the neutron star photosphere, which occurred not within a few seconds from the start of the burst, as is standard in radius-expansion bursts, but 20 s later. This suggests that two different layers of the neutron star may have undergone thermonuclear runaways: a hydrogen-rich and a hydrogen-poor layer. The reason for the delay may be related to the source being otherwise quiescent. C1 SRON, Natl Inst Space Res, NL-3584 CA Utrecht, Netherlands. Univ Utrecht, Astron Inst, NL-3508 TA Utrecht, Netherlands. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. RP SRON, Natl Inst Space Res, Sorbonnelaan 2, NL-3584 CA Utrecht, Netherlands. EM jeanz@sron.nl RI Swank, Jean/F-2693-2012 NR 29 TC 9 Z9 9 U1 0 U2 0 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 OCT PY 2003 VL 409 IS 2 BP 659 EP 663 DI 10.1051/0004-6361:20031042 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 725FW UT WOS:000185534000030 ER PT J AU Petry, D AF Petry, D TI Faster background determination - a method for gaining time coverage and flux measurement accuracy with Cherenkov telescopes SO ASTROPARTICLE PHYSICS LA English DT Article ID TEMPORAL CHARACTERISTICS; RADIATION; EMISSION; MKN-501; SYSTEM; HEGRA AB An improved way of taking off-source data for background determination in Cherenkov telescope (CT) observations is proposed. Generalizing the traditional concept of taking on-source/off-source observations of equal duration (e.g. 30 min ON followed by 30 min OFF), faster background determination permits an off-source observation with the same zenith angle distribution as the on-source observation to be obtained within less time. The method permits the onsource observation time to be maximized without compromising the quality of the background determination. It also increases the signal significance for strong sources. The only modification necessary in the data acquisition is a small change to the tracking algorithm. The only modification necessary in the data analysis is to introduce a time normalization which does not increase the systematic errors. The method could become the normal observing mode for CTs when observing strong sources. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Petry, D (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Astrophys, 1000 Hilltop Circle, Baltimore, MD 21250 USA. NR 10 TC 2 Z9 2 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 OCT PY 2003 VL 20 IS 1 BP 45 EP 52 DI 10.1016/S0927-6505(03)00139-7 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 724MQ UT WOS:000185491700003 ER PT J AU Bouwens, RJ Illingworth, GD Rosati, P Lidman, C Broadhurst, T Franx, M Ford, HC Magee, D Benitez, N Blakeslee, JP Meurer, GR Clampin, M Hartig, GF Ardila, DR Bartko, F Brown, RA Burrows, CJ Cheng, ES Cross, NJG Feldman, PD Golimowski, DA Gronwall, C Infante, L Kimble, RA Krist, JE Lesser, MP Martel, AR Menanteau, F Miley, GK Postman, M Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W AF Bouwens, RJ Illingworth, GD Rosati, P Lidman, C Broadhurst, T Franx, M Ford, HC Magee, D Benitez, N Blakeslee, JP Meurer, GR Clampin, M Hartig, GF Ardila, DR Bartko, F Brown, RA Burrows, CJ Cheng, ES Cross, NJG Feldman, PD Golimowski, DA Gronwall, C Infante, L Kimble, RA Krist, JE Lesser, MP Martel, AR Menanteau, F Miley, GK Postman, M Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W TI Star formation at z similar to 6: i-dropouts in the advanced camera for surveys guaranteed time observation fields SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : formation; galaxies : high-redshift ID HUBBLE-DEEP-FIELD; HIGH-REDSHIFT GALAXIES; LYMAN-BREAK GALAXIES; ULTRAVIOLET LUMINOSITY DENSITY; FORMATION HISTORY; RADIATIVE-TRANSFER; CLUMPY UNIVERSE; SPACE-TELESCOPE; EVOLUTION; PHOTOMETRY AB Using an i - z dropout criterion, we determine the space density of z similar to 6 galaxies from two deep ACS GTO fields with deep optical-IR imaging. A total of 23 objects are found over 46 arcmin(2), or similar to0.5 +/- 0.1 objects arcmin(-2) down to z(AB) similar to 27.3 (6 sigma), or a completeness-corrected similar to0.5 +/- 0.2 objects arcmin(-2) down to z(AB) similar to 26.5 (including one probable z similar to 6 active galactic nucleus). Combining deep ISAAC data for our RDCS 1252-2927 field (J(AB) similar to 25.7 and K-s;AB similar to 25.0; 5 sigma) and NICMOS data for the Hubble Deep Field North (J(110;AB) and H-160; AB similar to 27.3, 5 sigma), we verify that these dropouts have relatively. at spectral slopes, as one would expect for star-forming objects at z similar to 6. Compared with the average-color (beta = -1.3) U-dropout in the Steidel et al. z similar to 3 sample, i-dropouts in our sample range in luminosity from similar to1.5L(*) (z(AB) similar to 25.6) to similar to0.3L(*) (z(AB) similar to 27.3) with the exception of one very bright candidate at z(850; AB) similar to 24.2. The half-light radii vary from 0."09 to 0."21, or 0.5 kpc to 1.3 kpc. We derive the z similar to 6 rest-frame UV luminosity density (or star formation rate density) by using three different procedures. All three procedures use simulations based on a slightly lower redshift (z similar to 5) V-606-dropout sample from Chandra Deep Field-South ACS images. First, we make a direct comparison of our findings with a no-evolution projection of this V-dropout sample, allowing us to automatically correct for the light lost at faint magnitudes or lower surface brightnesses. We find 23% +/- 25% more i-dropouts than we predict, consistent with no strong evolution over this redshift range. Adopting previous results to z similar to 5, this works out to a mere 20% +/- 29% drop in the luminosity density from z similar to 3 to z similar to 6. Second, we use the same V-dropout simulations to derive a detailed selection function for our i-dropout sample and compute the UV-luminosity density [7.2 +/- 2.5) _x 10(25) ergs s(-1) Hz(-1) Mpc(-3) down to z(AB) similar to 27]. We find a 39% +/- 21% drop over the same redshift range (z similar to 3-6), consistent with the first estimate. This is our preferred value and suggests a star formation rate of 0.0090 +/- 0.0031 M-. yr(-1) Mpc(-3) to z(AB) similar to 27, or similar to 0.036 +/- 0.012 M-. yr(-1) Mpc(-3) by extrapolating the luminosity function to the faint limit, assuming alpha = - 1.6. Third, we follow a very similar procedure, except that we assume no incompleteness, and find a rest-frame continuum luminosity that is similar to2-3 times lower than our other two determinations. This final estimate is to be taken as a lower limit and is important if there are modest changes in the colors or surface brightnesses from z similar to 5 to z similar to 6 (the other estimates assume no large changes in the intrinsic selectability of objects). We note that all three estimates are well within the canonical range of luminosity densities necessary for reionization of the universe at this epoch by star-forming galaxies. C1 Univ Calif Santa Cruz, Dept Astron, Santa Cruz, CA 95064 USA. European So Observ, D-85748 Garching, Germany. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Leiden Observ, NL-2300 RA Leiden, Netherlands. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Bartko Sci & Technol, Mead, CO 80542 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Bouwens, RJ (reprint author), Univ Calif Santa Cruz, Dept Astron, Santa Cruz, CA 95064 USA. RI White, Richard/A-8143-2012; Clampin, mark/D-2738-2012; Kimble, Randy/D-5317-2012; OI Benitez, Narciso/0000-0002-0403-7455; Blakeslee, John/0000-0002-5213-3548 NR 49 TC 81 Z9 81 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP 589 EP 602 DI 10.1086/377477 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TJ UT WOS:000185675800002 ER PT J AU Xu, CK Lu, N Condon, JJ Dopita, M Tuffs, RJ AF Xu, CK Lu, N Condon, JJ Dopita, M Tuffs, RJ TI Physical conditions and star formation activity in the intragroup medium of Stephan's Quintet SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : interactions; galaxies : ISM; galaxies : starburst; infrared : galaxies; intergalactic medium ID VIRGO CLUSTER GALAXIES; ABUNDANT MOLECULAR GAS; TIDAL DWARF GALAXIES; X-RAY-EMISSION; RADIO-CONTINUUM; SPECTRAL SIGNATURES; DIAGNOSTIC DIAGRAMS; INFRARED-EMISSION; COMPACT-GROUPS; FAST SHOCKS AB New multiband observations of the famous compact group of galaxies Stephan's Quintet (SQ) are presented and analyzed. These include far-infrared (FIR) images at 60 and 100 mum (ISOPHOT C100 camera), radio continuum images at 1.4 GHz (VLA B configuration) and 4.86 GHz ( VLA C configuration), and long-slit optical spectrographs (Palomar 200" telescope). With these new data, we aim to learn more about the X-ray/radio ridge in the middle of the intragroup medium (IGM) and the IGM starburst SQ-A, both of which are likely to be caused by the high-speed collision (similar to900 km s(-1)) between the intruder galaxy NGC 7318b (v = 5700 km s(-1)) and the IGM (v = 6600 km s(-1)). We found that the radio ridge has a steep nonthermal spectral index (alpha = 0.93 +/- 0.13) and an extremely low FIR-to-radio ratio index (q < 0.59). Its IR emission can be explained in terms of collisional heating of dust grains by shocked gas. The minimum-energy magnetic field strength is H-min &AP; 10 μG. The long-slit spectra of sources in the ridge have typical emission-line ratios of shock-excited gas. The very broad line widths (&GE;1000 km s(-1)) and the fact that in some cases more than two velocity systems were detected along the same line of sight provide further evidence for an ongoing collision along the ridge. The IGM starburst SQ-A has a radio spectral index α = 0.8 +/- 0.3 and an FIR-to-radio ratio index q = 2.0 +/- 0.4, consistent with those of star-forming regions. The optical spectra of two sources in this region, M1 (v = 6600 km s(-1)) and M2 (v = 6000 km s(-1)), have typical line ratios of H II regions. Both M1 and M2 have metallicity slightly higher than the solar value. The star formation rate estimated from the extinction-corrected Hα luminosity of SQ-A is 1.45 M-. yr(-1), of which 1.25 M-. yr(-1) is due to the v = 6600 km s(-1) component and 0.20 M-. yr(-1) to the v = 6000 km s(-1) component. C1 CALTECH, Jet Prop Lab, Infrared Proc & Anal Ctr, Pasadena, CA 91125 USA. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Australian Natl Univ, Res Sch Astron & Astrophys, Weston, ACT 2611, Australia. Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. RP Xu, CK (reprint author), CALTECH, Jet Prop Lab, Infrared Proc & Anal Ctr, MS 100-22, Pasadena, CA 91125 USA. RI Dopita, Michael/P-5413-2014 OI Dopita, Michael/0000-0003-0922-4986 NR 66 TC 44 Z9 44 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP 665 EP 684 DI 10.1086/377445 PN 1 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TJ UT WOS:000185675800009 ER PT J AU Dursi, LJ Zingale, M Calder, AC Fryxell, B Timmes, FX Vladimirova, N Rosner, R Caceres, A Lamb, DQ Olson, K Ricker, PM Riley, K Siegel, A Truran, JW AF Dursi, LJ Zingale, M Calder, AC Fryxell, B Timmes, FX Vladimirova, N Rosner, R Caceres, A Lamb, DQ Olson, K Ricker, PM Riley, K Siegel, A Truran, JW TI The response of model and astrophysical thermonuclear flames to curvature and stretch SO ASTROPHYSICAL JOURNAL LA English DT Article DE conduction; hydrodynamics; methods : numerical; nuclear reactions, nucleosynthesis, abundances; supernovae : general; white dwarfs ID DELAYED-DETONATION MODEL; LANDAU-DARRIEUS INSTABILITY; IA SUPERNOVAE; WHITE-DWARFS; BURNING VELOCITIES; NUCLEAR FLAMES; LARGE-SCALE; FLAME/STRETCH INTERACTIONS; BOUNDARY-CONDITIONS; HYPERBOLIC SYSTEMS AB Critically understanding the standard candle-like behavior of Type Ia supernovae requires understanding their explosion mechanism. One family of models for Type Ia supernovae begins with a deflagration in a carbon-oxygen white dwarf that greatly accelerates through wrinkling and flame instabilities. While the planar speed and behavior of astrophysically relevant flames is increasingly well understood, more complex behavior, such as the flame's response to stretch and curvature, has not been extensively explored in the astrophysical literature; this behavior can greatly enhance or suppress instabilities and local flame-wrinkling, which in turn can increase or decrease the bulk burning rate. In this paper, we explore the effects of curvature on both nuclear flames and simpler model flames to understand the effect of curvature on the flame structure and speed. C1 Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Ctr Astrophys Thermonucl Flashes, Chicago, IL 60637 USA. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. Univ Chicago, Dept Phys, Chicago, IL 60637 USA. NASA, UMBC GEST Ctr, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP Dursi, LJ (reprint author), Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA. RI Calder, Alan/E-5348-2011; OI Zingale, Michael/0000-0001-8401-030X; Dursi, Jonathan/0000-0002-4697-798X NR 60 TC 13 Z9 13 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 OCT 1 PY 2003 VL 595 IS 2 BP 955 EP 979 DI 10.1086/377433 PN 1 PG 25 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TJ UT WOS:000185675800030 ER PT J AU Meier, DL AF Meier, DL TI Constrained transport algorithms for numerical relativity. I. Development of a finite-difference scheme SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; relativity ID RADIATION MAGNETOHYDRODYNAMICS CODE; 2 SPACE DIMENSIONS; ASTROPHYSICAL FLOWS; ZEUS-2D; TESTS AB A scheme is presented for accurately propagating the gravitational field constraints in finite-difference implementations of numerical relativity. The method is based on similar techniques used in astrophysical magnetohydrodynamics and engineering electromagnetics and has properties of a finite differential calculus on a four-dimensional manifold. It is motivated by the arguments that (1) an evolutionary scheme that naturally satisfies the Bianchi identities will propagate the constraints and (2) methods in which temporal and spatial derivatives commute will satisfy the Bianchi identities implicitly. The proposed algorithm exactly propagates the constraints in a local Riemann normal coordinate system; i.e., all terms in the Bianchi identities (which all vary as partial derivative(3)g) cancel to machine roundoff accuracy at each time step. In a general coordinate basis, these terms and those that vary as partial derivativegpartial derivative(2)g also can be made to cancel, but differences of connection terms, proportional to (partial derivativeg)(3), will remain, resulting in a net truncation error. Detailed and complex numerical experiments with four-dimensional staggered grids will be needed to completely examine the stability and convergence properties of this method. If such techniques are successful for finite-difference implementations of numerical relativity, other implementations, such as finite-element (and eventually pseudospectral) techniques, might benefit from schemes that use four-dimensional grids and that have temporal and spatial derivatives that commute. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Meier, DL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 7 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 OCT 1 PY 2003 VL 595 IS 2 BP 980 EP 991 DI 10.1086/377166 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TJ UT WOS:000185675800031 ER PT J AU Tournear, D Raffauf, E Bloom, ED Focke, W Giebels, B Godfrey, G Parkinson, PMS Reilly, KT Wood, KS Ray, PS Wolff, MT Bandyopadhyay, RM Lovellette, MN Scargle, JD AF Tournear, D Raffauf, E Bloom, ED Focke, W Giebels, B Godfrey, G Parkinson, PMS Reilly, KT Wood, KS Ray, PS Wolff, MT Bandyopadhyay, RM Lovellette, MN Scargle, JD TI X-ray bursts in neutron star and black hole binaries from Unconventional Stellar Aspect experiment and Rossi X-Ray Timing Explorer data: Detections and upper limits SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; stars : neutron; X-rays : binaries; X-rays : bursts ID RAPID-BURSTER; PROPORTIONAL COUNTER; XTE J1118+480; EVENT-HORIZON; CYGNUS X-2; MASS; FLASHES; TRANSIENTS; QUIESCENCE; SPECTRUM AB Narayan & Heyl have developed a theoretical framework to convert suitable upper limits on type I X-ray bursts from accreting black hole candidates (BHCs) into evidence for an event horizon. However, no appropriate observational limit exists in the literature. In this paper we survey 2101.2 ks of data from the Unconventional Stellar Aspect (USA) X-ray timing experiment and 5142 ks of data from the Rossi X-Ray Timing Explorer (RXTE) experiment to obtain a formal constraint of this type. We find that 1122 ks of neutron star data yield a population-averaged mean burst rate of (1.7 +/- 0.4) x 10(-5) bursts s(-1), while 6081 ks of BHC data yield a 95% confidence level upper limit of 4.9 x 10(-7) bursts s(-1). This is the first published limit of this type for BHCs. Applying the theoretical framework of Narayan & Heyl, we calculate regions of unstable luminosity, where the neutron stars are expected to burst and the BHCs would be expected to burst if they had a surface. In this unstable luminosity region, 464 ks of neutron star data yield an averaged mean burst rate of (4.1 +/- 0.8) x 10(-5) bursts s(-1), and 1512 ks of BHC data yield a 95% confidence level upper limit of 2.0 x 10(-6) bursts s(-1) and a strong limit that BHCs do not burst with a rate similar to the rate of neutron stars in these unstable regions. This gives further evidence that BHCs do not have surfaces unless there is some new physics occurring on their surface. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. USN, EO Hulburt Ctr Space Res, Res Lab, Washington, DC 20375 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Tournear, D (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. OI Ray, Paul/0000-0002-5297-5278 NR 57 TC 12 Z9 12 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP 1058 EP 1065 DI 10.1086/377431 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TJ UT WOS:000185675800038 ER PT J AU Corbet, RHD AF Corbet, RHD TI Long-term X-ray variability in GX 13+1: Energy-dependent periodic modulation SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : individual (GX 13+1); stars : neutron; X-rays : stars ID TIMING-EXPLORER OBSERVATIONS; ABSORPTION-LINE FEATURES; SOURCE GRO J1655-40; INFRARED OBSERVATIONS; RADIO OBSERVATIONS; SPECTRAL BEHAVIOR; GX 13+1; BINARIES; DISCOVERY; COUNTERPART AB A search is made for periodic modulation in the X-ray flux from the low-mass X-ray binary GX13+1 using Rossi X-Ray Timing Explorer All Sky Monitor data collected over a period of almost 7 yr. From a filtered data set, which excludes measurements with exceptionally large error bars and so maximizes signal-to-noise ratio, modulation is found at a period of 24.065 +/- 0.018 days. The modulation is most clearly detectable at high energies (5-12 keV). Spectral changes are revealed as a modulation in hardness ratio on the 24 day period, and there is a phase shift between the modulation in the 5-12 keV energy band and the 1.5-5 keV band. The high-energy spectrum of GX13+1 is unusual in displaying both emission and absorption iron line features, and it is speculated that the peculiar spectral and timing properties may be connected. C1 NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Corbet, RHD (reprint author), Univ Space Res Assoc, Columbia, MD 21044 USA. NR 34 TC 21 Z9 21 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP 1086 EP 1093 DI 10.1086/377469 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TJ UT WOS:000185675800041 ER PT J AU Bouret, JC Lanz, T Hillier, DJ Heap, SR Hubeny, I Lennon, DJ Smith, LJ Evans, CJ AF Bouret, JC Lanz, T Hillier, DJ Heap, SR Hubeny, I Lennon, DJ Smith, LJ Evans, CJ TI Quantitative spectroscopy of O stars at low metallicity: O dwarfs in NGC 346 SO ASTROPHYSICAL JOURNAL LA English DT Article DE Magellanic Clouds; stars : abundances; stars : atmospheres; stars : early-type; stars : fundamental parameters; stars : mass loss ID SMALL-MAGELLANIC-CLOUD; RADIATION-DRIVEN WINDS; HOT LUMINOUS STARS; BLANKETED MODEL ATMOSPHERES; STELLAR WINDS; NON-LTE; MASS-LOSS; EXPANDING ATMOSPHERES; TERMINAL VELOCITIES; ROTATING STARS AB We present the results of a detailed analysis of the properties of dwarf O-type stars in a metal-poor environment. High-resolution, high-quality ultraviolet and optical spectra of six O-type stars in the H II region NGC 346 have been obtained from a spectroscopic survey of O stars in the SMC. Stellar parameters and chemical abundances have been determined using non-LTE (NLTE) line-blanketed photospheric models calculated with TLUSTY. Additionally, we have modeled the spectra with the NLTE line-blanketed wind code CMFGEN to derive wind parameters. Stellar parameters, chemical abundances, and in particular iron abundances obtained with the two NLTE codes compare quite favorably. This consistency demonstrates that basic photospheric parameters of main-sequence O stars can be reliably determined using NLTE static model atmospheres. With the two NLTE codes, we need to introduce a microturbulent velocity to match the observed spectra. Our results hint at a decrease of the required microturbulent velocity from a value close to the sonic velocity in early O stars to a low value in late O stars. As in several recent studies of Galactic, LMC, and SMC stars, we derive effective temperatures lower than predicted from the widely used relation between spectral type and T(eff), resulting in lower stellar luminosities and lower ionizing fluxes. From evolutionary tracks in the H-R diagram, we find the age 3 x 10(6) yr for NGC 346. A majority of the stars in our sample reveal CNO cycle-processed material at their surface during the main-sequence stage, thus indicating fast stellar rotation and/or very efficient mixing processes. We obtain an overall metallicity Z = 0.2 Z., in good agreement with other recent analyses of SMC stars. We study the dependence of the mass-loss rate on the stellar metallicity and find a satisfactory agreement with recent theoretical predictions for the three most luminous stars of the sample. The wind momentum-luminosity relation for our sample stars derived for these stars agrees with previous studies. However, the three other stars of our sample reveal very weak signatures of mass loss. We obtain mass-loss rates that are significantly lower than 10(-8) M. yr(-1), below the predictions of radiative line-driven wind theory by an order of magnitude or more. Furthermore, evidence of clumping in the wind of main-sequence O stars is provided by O V lambda1371. As in previous studies of O star winds, we are unable to reproduce this line with homogeneous-wind models, but we have achieved very good fits with clumped models. Clumped-wind models systematically yield lower mass-loss rates than theoretical predictions. C1 Lab Astrophys Marseille, F-13376 Marseille 12, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. Isaac Newton Grp, Santa Cruz De La Palma 38700, Canary Island, Spain. UCL, Dept Phys & Astron, London WC1E 6BT, England. RP Bouret, JC (reprint author), Lab Astrophys Marseille, Traverse Siphon,BP 8, F-13376 Marseille 12, France. EM Jean-Claude.Bouret@astrsp-mrs.fr; lanz@stars.gsfc.nasa.gov RI heap, sara/E-2237-2012 NR 72 TC 179 Z9 179 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 OCT 1 PY 2003 VL 595 IS 2 BP 1182 EP 1205 DI 10.1086/377368 PN 1 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TJ UT WOS:000185675800049 ER PT J AU Holman, GD Sui, LH Schwartz, RA Emslie, AG AF Holman, GD Sui, LH Schwartz, RA Emslie, AG TI Electron bremsstrahlung hard X-ray spectra, electron distributions, and energetics in the 2002 July 23 solar flare SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : flares; Sun : X-rays, gamma rays ID BURSTS; MODEL AB We present and analyze the first high-resolution hard X-ray spectra from a solar flare observed in both X-ray/gamma-ray continuum and gamma-ray lines. Spatially integrated photon flux spectra obtained by the Ramaty High Energy Solar Spectroscopic Imager (RHESSI) are well fitted between 10 and 300 keV by the combination of an isothermal component and a double power law. The flare plasma temperature peaks at 40 MK around the time of peak hard X-ray emission and remains above 20 MK 37 minutes later. We derive the nonthermal mean electron flux distribution in one time interval by directly fitting the RHESSI X-ray spectrum with the thin-target bremsstrahlung from a double-power-law electron distribution with a low-energy cutoff. We find that relativistic effects significantly impact the bremsstrahlung spectrum above 100 keV and, therefore, the deduced mean electron flux distribution. We derive the evolution of the injected electron flux distribution on the assumption that the emission is thick-target bremsstrahlung. The injected nonthermal electrons are well described throughout the flare by a double-power-law distribution with a low-energy cutoff that is typically between 20 and 40 keV. We find that the power in nonthermal electrons peaks before the impulsive rise of the hard X-ray and gamma-ray emissions. We compare the energy contained in the nonthermal electrons with the energy content of the thermal flare plasma observed by RHESSI and GOES. The minimum total energy deposited into the flare plasma by nonthermal electrons, 2.6 x 10(31) ergs, is on the order of the energy in the thermal plasma. C1 NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RP Holman, GD (reprint author), NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Code 682, Greenbelt, MD 20771 USA. RI Holman, Gordon/C-9548-2012 NR 17 TC 194 Z9 195 U1 1 U2 7 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP L97 EP L101 DI 10.1086/378488 PN 2 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TK UT WOS:000185676000007 ER PT J AU Hurford, GJ Schwartz, RA Krucker, S Lin, RP Smith, DM Vilmer, N AF Hurford, GJ Schwartz, RA Krucker, S Lin, RP Smith, DM Vilmer, N TI First gamma-ray images of a solar flare SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : observations; Sun : flares; Sun : X-rays, gamma rays ID MAGNETIC LOOPS; RHESSI; ACCELERATION; PARTICLES; EMISSION AB Imaging of gamma-ray lines, produced by nuclear collisions of energetic ions with the solar atmosphere, provides the only direct indication of the spatial properties of accelerated ions near the Sun. We present the first gamma-ray images of a solar flare, obtained with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) for the X4.8 flare of 2002 July 23. Two rotating modulation collimators (with 35" and 183" resolution) were used to obtain images for the same time interval in four energy bands: the narrow deuterium line at 2.223 MeV formed by the thermalization and capture of neutrons produced in the collisions; the 3.25-6.5 MeV band that includes the prompt de-excitation lines of C and O; and the 0.3-0.5 and 0.7-1.4 MeV bands that are dominated by electron bremsstrahlung. The centroid of the 2.223 MeV image was found to be displaced by 20" +/- 6" from that of the 0.3-0.5 MeV image, implying a difference in acceleration and/or propagation between the accelerated electron and ion populations near the Sun. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Observ Paris, LESIA, F-92195 Meudon, France. RP Hurford, GJ (reprint author), Univ Calif Berkeley, Space Sci Lab, 7 Gauss Way, Berkeley, CA 94720 USA. NR 22 TC 92 Z9 96 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP L77 EP L80 DI 10.1086/378179 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TK UT WOS:000185676000002 ER PT J AU Kontar, EP Brown, JC Emslie, AG Schwartz, RA Smith, DM Alexander, RC AF Kontar, EP Brown, JC Emslie, AG Schwartz, RA Smith, DM Alexander, RC TI An explanation for non-power-law behavior in the hard X-ray spectrum of the 2002 July 23 solar flare SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : flares; Sun : transition region; Sun : X-rays, gamma rays ID ELECTRON-SPECTRA; BREMSSTRAHLUNG; POLARIZATION; IONIZATION; ANISOTROPY; BURSTS AB High-resolution Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) data reveal that solar flare hard X-ray spectra show systematic deviations from power-law behavior. Even for injection of a power-law electron spectrum, such deviations are expected because of a number of effects, including nonuniform target ionization and solar albedo backscattering of the primary hard X-ray flux. In this Letter, we examine 1 keV resolution hard X-ray spectra for the intense 2002 July 23 event, corrected for the effects of decimation, pulse pileup, and background. We find that the observed spectra indeed deviate from a power-law behavior in a manner consistent with the effects of nonuniform target ionization. Further, this interpretation of the observed deviations requires that the amount of coronal material increases during the initial phase of the flare. The implications of this discovery for models of atmospheric response to flare heating are discussed. C1 Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NASA, Sci Syst & Applicat Inc, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Kontar, EP (reprint author), Univ Glasgow, Dept Phys & Astron, Kelvin Bldg, Glasgow G12 8QQ, Lanark, Scotland. RI Kontar, Eduard/B-7897-2008 OI Kontar, Eduard/0000-0002-8078-0902 NR 23 TC 35 Z9 35 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP L123 EP L126 DI 10.1086/378172 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TK UT WOS:000185676000013 ER PT J AU Lin, RP Krucker, S Hurford, GJ Smith, DM Hudson, HS Holman, GD Schwartz, RA Dennis, BR Share, GH Murphy, RJ Emslie, AG Johns-Krull, C Vilmer, N AF Lin, RP Krucker, S Hurford, GJ Smith, DM Hudson, HS Holman, GD Schwartz, RA Dennis, BR Share, GH Murphy, RJ Emslie, AG Johns-Krull, C Vilmer, N TI RHESSI observations of particle acceleration and energy release in an intense solar gamma-ray line flare SO ASTROPHYSICAL JOURNAL LA English DT Article DE acceleration of particles; Sun : flares; Sun : X-rays; gamma rays ID EMISSION; ABUNDANCES; SPECTRA AB We summarize Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) hard X-ray (HXR) and gray imaging and spectroscopy observations of the intense (X4.8) gamma-ray line flare of 2002 July 23. In the initial rise, a new type of coronal HXR source dominates that has a steep double-power-law X-ray spectrum and no evidence of thermal emission above 10 keV, indicating substantial electron acceleration to tens of keV early in the flare. In the subsequent impulsive phase, three footpoint sources with much flatter double-power-law HXR spectra appear, together with a coronal superhot (T similar to 40 MK) thermal source. The north footpoint and the coronal source both move systematically to the north-northeast at speeds up to similar to50 km s(-1). This footpoint's HXR flux varies approximately with its speed, consistent with magnetic reconnection models, provided the rate of electron acceleration varies with the reconnection rate. The other footpoints show similar temporal variations but do not move systematically, contrary to simple reconnection models. The gamma-ray line and continuum emissions show that ions and electrons are accelerated to tens of MeV during the impulsive phase. The prompt de-excitation gamma-ray lines of Fe, Mg, Si, Ne, C, and O-resolved here for the first time-show mass-dependent redshifts of 0.1%-0.8%, implying a downward motion of accelerated protons and alpha-particles along magnetic field lines that are tilted toward the Earth by similar to40degrees. For the first time, the positron annihilation line is resolved, and the detailed high-resolution measurements are obtained for the neutron-capture line. The first ever solar gamma-ray line and continuum imaging shows that the source locations for the relativistic electron bremsstrahlung overlap the 50-100 keV HXR sources, implying that electrons of all energies are accelerated in the same region. The centroid of the ion-produced 2.223 MeV neutron-capture line emission, however, is located similar to20" +/- 6" away, implying that the acceleration and/or propagation of the ions must differ from that of the electrons. Assuming that Coulomb collisions dominate the energetic electron and ion energy losses (thick target), we estimate that a minimum of similar to2 x 10(31) ergs is released in accelerated >similar to20 keV electrons during the rise phase, with similar to10(31) ergs in ions above 2.5 MeV nucleon(-1) and about the same in electrons above 30 keV released in the impulsive phase. Much more energy could be in accelerated particles if their spectra extend to lower energies. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Res Lab, Washington, DC 20375 USA. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. Observ Paris, LESIA, F-92195 Meudon, France. RP Lin, RP (reprint author), Univ Calif Berkeley, Space Sci Lab, Grizzly Peak & Centennial Dr, Berkeley, CA 94720 USA. RI Dennis, Brian/C-9511-2012; Holman, Gordon/C-9548-2012 NR 39 TC 218 Z9 227 U1 1 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP L69 EP L76 DI 10.1086/378932 PN 2 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TK UT WOS:000185676000001 ER PT J AU Murphy, RJ Share, GH Hua, XM Lin, RP Smith, DM Schwartz, RA AF Murphy, RJ Share, GH Hua, XM Lin, RP Smith, DM Schwartz, RA TI Physical implications of RHESSI neutron-capture line measurements SO ASTROPHYSICAL JOURNAL LA English DT Article DE acceleration of particles; nuclear reactions, nucleosynthesis, abundances Sun : abundances; Sun : flares; Sun : X-rays, gamma rays; turbulence ID GAMMA-RAY LINE; FLARE MAGNETIC LOOPS; SOLAR-FLARE; EMISSION; PROPAGATION; ABUNDANCES; PARTICLES AB We report high spectral resolution measurements of the 2.223 MeV neutron-capture line obtained with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) from the 2002 July 23 solar flare. The time history of this line is affected by both the photospheric He-3 abundance and the angular distribution of the interacting flare-accelerated particles producing the neutrons. The measured time history is compared with predicted time histories calculated using a magnetic loop model with a magnetic field perpendicular to the solar surface at the footpoints. The model includes energy losses due to Coulomb collisions, removal by nuclear reactions, magnetic mirroring in the convergent flux tube, and MHD pitch-angle scattering in the corona. This is the first analysis of the neutron-capture line using such a physically based model. The derived constraints on the interacting angular distribution require that the accelerated particles had to suffer pitch-angle scattering during their transport through the coronal portion of the loop. The derived photospheric He-3/H ratio was not well constrained, primarily because of uncertainties associated with the measured nuclear de-excitation line flux used to represent the neutron-production time profile. C1 USN, EO Hulburt Ctr Space Res, Res Lab, Washington, DC 20375 USA. EER Syst Inc, L3 Commun, Largo, MD 20774 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Murphy, RJ (reprint author), USN, EO Hulburt Ctr Space Res, Res Lab, Code 7650, Washington, DC 20375 USA. NR 18 TC 28 Z9 30 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP L93 EP L96 DI 10.1086/378175 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TK UT WOS:000185676000006 ER PT J AU Piana, M Massone, AM Kontar, EP Emslie, AG Brown, JC Schwartz, RA AF Piana, M Massone, AM Kontar, EP Emslie, AG Brown, JC Schwartz, RA TI Regularized electron flux spectra in the 2002 July 23 solar flare SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : flares ID X-RAY-SPECTRA; BREMSSTRAHLUNG SPECTRA; INVERSION AB By inverting the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) hard X-ray photon spectrum with the Tikhonov regularization algorithm, we infer the effective mean electron source spectrum for a time interval near the peak of the 2002 July 23 event. This inverse approach yields the smoothest electron flux spectrum consistent with the data while retaining real features, such as local minima, that cannot be found with forward model-fitting methods that involve only a few parameters. A significant dip in the recovered mean source electron spectrum near E = 55 keV is noted, and its significance briefly discussed. C1 Univ Genoa, Ist Nazl Fis Mat, I-16146 Genoa, Italy. Univ Genoa, Dipartimento Matemat, I-16146 Genoa, Italy. Ist Nazl Fis Mat, Unita Ric Genova, I-16146 Genoa, Italy. Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. NASA, Sci Syst & Applicat Inc, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Piana, M (reprint author), Univ Genoa, Ist Nazl Fis Mat, Via Dodecaneso 15, I-16146 Genoa, Italy. RI Kontar, Eduard/B-7897-2008; piana, michele/H-9376-2015; OI Kontar, Eduard/0000-0002-8078-0902; PIANA, MICHELE/0000-0003-1700-991X NR 19 TC 67 Z9 67 U1 1 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP L127 EP L130 DI 10.1086/378171 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TK UT WOS:000185676000014 ER PT J AU Share, GH Murphy, RJ Smith, DM Lin, RP Dennis, BR Schwartz, RA AF Share, GH Murphy, RJ Smith, DM Lin, RP Dennis, BR Schwartz, RA TI Directionality of flare-accelerated alpha-particles at the Sun SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : flares; Sun : particle emission; Sun : X-rays, gamma rays ID GAMMA-RAY LINES; SOLAR-FLARES; PROBES; RHESSI AB The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) has observed the Be-7 and Li-7 gamma-ray lines from fusion of accelerated alpha-particles with ambient helium produced during the 2002 July 23 solar flare that erupted at a heliocentric angle of 73degrees. This is the first observation of the lines with a germanium spectrometer. We have fitted the measured lines with calculated shapes for different energy and angular distributions for the interacting alpha-particles. A particle distribution from saturated pitch-angle scattering in the corona provides the best fit, but isotropic, downward-isotropic, or fan-beam distributions also provide acceptable fits. We can rule out a downward-beamed distribution with 99.99% confidence. RHESSI measurements of other Doppler-shifted nuclear de-excitation lines are consistent with a forward isotropic distribution of interacting particles in a magnetic loop tilted by similar to40degrees from the normal to the solar surface toward Earth. Such a distribution is also consistent with the alpha-He-4 line shape with similar to15% confidence. C1 USN, EO Hulburt Ctr Space Res, Res Lab, Washington, DC 20375 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Share, GH (reprint author), USN, EO Hulburt Ctr Space Res, Res Lab, 4555 Overlook Ave SW, Washington, DC 20375 USA. RI Dennis, Brian/C-9511-2012 NR 16 TC 19 Z9 19 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP L89 EP L92 DI 10.1086/378176 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TK UT WOS:000185676000005 ER PT J AU Share, GH Murphy, RJ Skibo, JG Smith, DM Hudson, HS Lin, RP Shih, AY Dennis, BR Schwartz, RA Kozlovsky, B AF Share, GH Murphy, RJ Skibo, JG Smith, DM Hudson, HS Lin, RP Shih, AY Dennis, BR Schwartz, RA Kozlovsky, B TI High-resolution observation of the solar positron-electron annihilation line SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : flares; Sun : particle emission; Sun : x-rays, gamma rays ID FLARE MAGNETIC LOOPS; RHESSI; PARTICLES; EMISSION; MODELS; SUN AB The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) has observed the positron-electron annihilation line at 511 keV produced during the 2002 July 23 solar flare. The shape of the line is consistent with annihilation in two vastly different solar environments. It can be produced by formation of positronium by charge exchange in flight with hydrogen in a quiet solar atmosphere at a temperature of similar to6000 K. However, the measured upper limit to the 3gamma/2gamma ratio (ratio of annihilation photons in the positronium continuum to the number in the line) is only marginally consistent with what is calculated for this environment. The annihilation line can also be fitted by a thermal Gaussian having a width of 8.1 +/- 1.1 keV (FWHM), indicating temperatures of similar to(4-7) x 10(5) K. The measured 3gamma/2gamma ratio does not constrain the density when the annihilation takes place in such an ionized medium, although the density must be high enough to slow down the positrons. This would require the formation of a substantial mass of atmosphere at transition-region temperatures during the flare. C1 USN, EO Hulburt Ctr Space Res, Res Lab, Washington, DC 20375 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. RP USN, EO Hulburt Ctr Space Res, Res Lab, 4555 Overlook Ave SW, Washington, DC 20375 USA. EM gerald.share@nrl.navy.mil; ronald.murphy@nrl.navy.mil; slaase@rcn.com; dsmith@ssl.berkeley.edu; hhudson@ssl.berkeley.edu; rlin@ssl.berkeley.edu; ashih@ssl.berkeley.edu; brian.r.dennis@nasa.gov; richard.schwartz@gsfc.nasa.gov; benz@wise.tau.ac.il RI Dennis, Brian/C-9511-2012; Shih, Albert/D-4714-2012 NR 19 TC 29 Z9 29 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP L85 EP L88 DI 10.1086/378174 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TK UT WOS:000185676000004 ER PT J AU Smith, DM Share, GH Murphy, RJ Schwartz, RA Shih, AY Lin, RP AF Smith, DM Share, GH Murphy, RJ Schwartz, RA Shih, AY Lin, RP TI High-resolution spectroscopy of gamma-ray lines from the X-class solar flare SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : observations; line : profiles; Sun : flares; Sun : X-rays, gamma rays ID ALPHA-PARTICLES; DIRECTIONALITY; ABUNDANCES; RHESSI AB The Reuven Ramaty High Energy Solar Spectroscopy Imager (RHESSI) has obtained the first high-resolution measurements of nuclear de-excitation lines produced by energetic ions accelerated in a solar flare, a GOES X4.8 event occurring on 2002 July 23 at a heliocentric angle of similar to73degrees. Lines of neon, magnesium, silicon, iron, carbon, and oxygen were resolved for the first time. They exhibit Doppler redshifts of 0.1%-0.8% and broadening of 0.1%-2.1% (FWHM), generally decreasing with mass. The measured redshifts are larger than expected for a model of an interacting ion distribution isotropic in the downward hemisphere in a radial magnetic field. Possible interpretations of the large redshifts include (1) an inclination of the loop magnetic field to the solar surface so that the ion distribution is oriented more directly away from the observer and (2) extreme beaming of the ions downward along a magnetic field normal to the solar surface. Bulk downward motion of the plasma in which the accelerated ions interact can be ruled out. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. USN, EO Hulburt Ctr Space Res, Res Lab, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst Applicat Inc, Lanham, MD 20706 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Smith, DM (reprint author), Univ Calif Santa Cruz, Dept Phys, 1156 High St, Santa Cruz, CA 95064 USA. RI Shih, Albert/D-4714-2012 NR 18 TC 58 Z9 59 U1 1 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD OCT 1 PY 2003 VL 595 IS 2 BP L81 EP L84 DI 10.1086/378173 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TK UT WOS:000185676000003 ER PT J AU Schmitt, HR Donley, JL Antonucci, RRJ Hutchings, JB Kinney, AL AF Schmitt, HR Donley, JL Antonucci, RRJ Hutchings, JB Kinney, AL TI A Hubble Space Telescope survey of extended [O III] lambda 5007 emission in a far-infrared selected sample of Seyfert galaxies: Observations SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE galaxies : active; galaxies : nuclei; galaxies : Seyfert; galaxies : structure; surveys ID NARROW-LINE REGION; RESOLUTION RADIO OBSERVATIONS; ACTIVE GALACTIC NUCLEI; POINT-SOURCE CATALOG; WARM IRAS SOURCES; NGC 1068; JET DIRECTIONS; OPTICAL SPECTROSCOPY; IONIZING-RADIATION; UNIFIED SCHEMES AB We present a Hubble Space Telescope (HST) survey of extended [O III] emission for a sample of 60 Seyfert galaxies (22 Seyfert 1 galaxies and 38 Seyfert 2 galaxies), selected based on their far-infrared properties. The observations for 42 of these galaxies were done in a snapshot survey with WFPC2. The remaining 18 were obtained from the HST archive, most of which were observed with the same configuration. These observations cover 68% of the objects in the sample defined by Kinney et al. and create a valuable data set for the study of the narrow-line region (NLR) properties of Seyfert galaxies. In this paper, we present the details of the observations, reductions, and measurements. We also discuss the extended structure of individual sources, and the relation of this emission to the radio and host galaxy morphology. We also address how representative the subsample of [O III]-imaged galaxies is of the entire sample, and possible selection effects that may affect this comparison of the properties of Seyfert 1 and Seyfert 2 galaxies. C1 Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Natl Res Council Canada, Herzberg Inst Astrophys, Dominion Astrophys Observ, Victoria, BC V9E 2E7, Canada. NASA Headquarters, Washington, DC 20546 USA. RP Schmitt, HR (reprint author), Natl Radio Astron Observ, 520 Edgemont Rd, Charlottesville, VA 22903 USA. NR 72 TC 95 Z9 96 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD OCT PY 2003 VL 148 IS 2 BP 327 EP 352 DI 10.1086/377440 PG 26 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TN UT WOS:000185676300004 ER PT J AU Crill, BP Ade, PAR Artusa, DR Bhatia, RS Bock, JJ Boscaleri, A Cardoni, P Church, SE Coble, K de Bernardis, P de Troia, G Farese, P Ganga, KM Giacometti, M Haynes, CV Hivon, E Hristov, VV Iacoangeli, A Jones, WC Lange, AE Martinis, L Masi, S Mason, PV Mauskopf, PD Miglio, L Montroy, T Netterfield, CB Paine, CG Pascale, E Piacentini, F Polenta, G Pongetti, F Romeo, G Ruhl, JE Scaramuzzi, F Sforna, D Turner, AD AF Crill, BP Ade, PAR Artusa, DR Bhatia, RS Bock, JJ Boscaleri, A Cardoni, P Church, SE Coble, K de Bernardis, P de Troia, G Farese, P Ganga, KM Giacometti, M Haynes, CV Hivon, E Hristov, VV Iacoangeli, A Jones, WC Lange, AE Martinis, L Masi, S Mason, PV Mauskopf, PD Miglio, L Montroy, T Netterfield, CB Paine, CG Pascale, E Piacentini, F Polenta, G Pongetti, F Romeo, G Ruhl, JE Scaramuzzi, F Sforna, D Turner, AD TI BOOMERANG: A balloon-borne millimeter-wave telescope and total power receiver for mapping anisotropy in the cosmic microwave background SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE balloons; cosmic microwave background; instrumentation : miscellaneous ID GALACTIC DUST EMISSION; NUMERICAL OPTIMIZATION; MULTIPLE PEAKS; RADIATION; MAPS; SPECTRUM; SYSTEM AB We describe BOOMERANG, a balloon-borne microwave telescope designed to map the cosmic microwave background at a resolution of 10' from the Long Duration Balloon (LDB) platform. The millimeter-wave receiver employs new technology in bolometers, readout electronics, cold reimaging optics, millimeter-wave filters, and cryogenics to obtain high sensitivity to cosmic microwave background anisotropy. Sixteen detectors observe in four spectral bands centered at 90, 150, 240, and 410 GHz. The wide frequency coverage, the long-duration flight, the optical design, and the observing strategy provide strong rejection of systematic effects. We report the flight performance of the instrument during a 10.5 day stratospheric balloon flight launched from McMurdo Station, Antarctica, that mapped similar to2000 square degrees of the sky. C1 CALTECH, Observ Cosmol, Pasadena, CA 91125 USA. Cardiff Univ, Dept Phys & Astron, Cardiff CF24 3YB, S Glam, Wales. Jet Prop Lab, Pasadena, CA USA. CNR, IROE, I-50127 Florence, Italy. ENEA, Frascati, Italy. Stanford Univ, Dept Phys, Palo Alto, CA 94304 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Adler Planetarium & Astron Museum, Chicago, IL USA. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. Univ London Queen Mary & Westfield Coll, London E1 4NS, England. Univ Toronto, Dept Astron, Toronto, ON M5S 3H8, Canada. Ist Nazl Geofis, I-00161 Rome, Italy. Case Western Reserve Univ, Dept Phys, Cleveland, OH 44106 USA. RP Crill, BP (reprint author), Calif State Univ Dominguez Hills, Dept Phys, Carson, CA 90747 USA. RI Piacentini, Francesco/E-7234-2010; OI Piacentini, Francesco/0000-0002-5444-9327; Masi, Silvia/0000-0001-5105-1439; de Bernardis, Paolo/0000-0001-6547-6446; ROMEO, Giovanni/0000-0002-5535-7803; Polenta, Gianluca/0000-0003-4067-9196; Hivon, Eric/0000-0003-1880-2733 NR 38 TC 53 Z9 53 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD OCT PY 2003 VL 148 IS 2 BP 527 EP 541 DI 10.1086/376894 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 727TN UT WOS:000185676300011 ER PT J AU Mallet, M Roger, JC Despiau, S Dubovik, O Putaud, JP AF Mallet, M Roger, JC Despiau, S Dubovik, O Putaud, JP TI Microphysical and optical properties of aerosol particles in urban zone during ESCOMPTE SO ATMOSPHERIC RESEARCH LA English DT Article DE aerosol; aerosol number size distribution; chemical composition; aerosol optical properties; climate change ID BIOMASS BURNING AEROSOLS; MID-ATLANTIC COAST; SIZE DISTRIBUTIONS; CARBONACEOUS AEROSOLS; ATMOSPHERIC AEROSOLS; UNITED-STATES; SOOT AEROSOLS; MEXICO-CITY; SULFATE; POLLUTION AB Microphysical and optical properties of the main aerosol species on a peri-urban site have been investigated during the ESCOMPTE experiment. Ammonium sulfate (AS), nitrate (N), black carbon (BC), particulate organic matter (POM), sea salt (SS) and mineral aerosol (D) size distributions have been used, associated with their refractive index, to compute, from the Mie theory, the key radiative aerosol properties as the extinction coefficient K-ext, the mass extinction efficiencies sigma(ext), the single scattering albedo omega(0) and the asymmetry parameter g at the wavelength of 550 nm. Optical computations show that 90% of the light extinction is due to anthropogenic aerosol and only 10% is due to natural aerosol (SS and D). 44 +/- 6% of the extinction is due to (AS) and 40 6% to carbonaceous particles (20 +/- 4% to BC and 21 +/- 4% to POM). Nitrate aerosol has a weak contribution of 5 +/- 2%. Computations of the mass extinction efficiencies a,, single scattering albedo omega(0) and asymmetry parameter g indicate that the optical properties of the anthropogenic aerosol are often quite different from those yet published and generally used in global models. For example, the (AS) mean specific mass extinction presents a large difference with the value classically adopted at low relative humidity (h < 60%) (2.6 +/- 0.5 instead of 6 m(2) g(-1) at 550 nm). The optical properties of the total aerosol layer, including all the aerosol species, indicate a mean observed single-scattering albedo omega(0) = 0.85 +/- 0.05, leading to an important absorption of the solar radiation and an asymmetry parameter g = 0.59 +/- 0.05 which are in a reasonably good agreements with the AERONET retrieval of omega(0) (= 0.86 +/- 0.05) and g (= 0.64 +/- 0.05) at this wavelength. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Toulon & Var, LEPI, F-83957 La Garde, France. Joint Res Ctr, Ispra, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Mallet, M (reprint author), Univ Toulon & Var, LEPI, F-83957 La Garde, France. RI Dubovik, Oleg/A-8235-2009 OI Dubovik, Oleg/0000-0003-3482-6460 NR 58 TC 74 Z9 76 U1 1 U2 12 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0169-8095 J9 ATMOS RES JI Atmos. Res. PD OCT-DEC PY 2003 VL 69 IS 1-2 BP 73 EP 97 DI 10.1016/j.stmosres.2003.07.001 PG 25 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 752HK UT WOS:000187154900004 ER PT J AU Clancey, WJ AF Clancey, WJ TI The Newell Test should commit to diagnosing dysfunctions SO BEHAVIORAL AND BRAIN SCIENCES LA English DT Editorial Material AB "Conceptual coordination" analysis bridges connectionism and symbolic approaches by positing a "process memory" by which categories are physically coordinated (as neural networks) in time. Focusing on dysfunctions and odd behaviors, like slips, reveals the function of consciousness, especially constructive processes that are often taken for granted, which are different from conventional programming constructs. Newell strongly endorsed identifying architectural limits; the heuristic of "diagnose unusual behaviors" will provide targets of opportunity that greatly strengthen the Newell Test. C1 NASA, Ames Res Ctr, Computat Sci Div, Moffett Field, CA 94035 USA. RP Clancey, WJ (reprint author), NASA, Ames Res Ctr, Computat Sci Div, MS 269-3, Moffett Field, CA 94035 USA. EM william.j.clancey@nasa.gov NR 7 TC 1 Z9 1 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0140-525X J9 BEHAV BRAIN SCI JI Behav. Brain Sci. PD OCT PY 2003 VL 26 IS 5 BP 604 EP + PG 9 WC Psychology, Biological; Behavioral Sciences; Neurosciences SC Psychology; Behavioral Sciences; Neurosciences & Neurology GA 837FJ UT WOS:000222613600027 ER PT J AU Nelson, R Valenti, MA Short, A Keller, C AF Nelson, R Valenti, MA Short, A Keller, C TI A multiple resource inventory of Delaware using airborne laser data SO BIOSCIENCE LA English DT Article DE airborne laser; multiresource inventory; forest biomass ID FOREST STAND CHARACTERISTICS; TROPICAL FOREST; CARBON SINK; BRAZILIAN AMAZON; CLIMATE-CHANGE; SCANNER DATA; BIOMASS; DEFORESTATION; VOLUME; LIDAR AB Estimates of forest wood volume and biomass, and estimates of the surface area of asphalt, concrete, roof, and open water, were generated from a single set of airborne laser-profiling data acquired during the summer of 2000. Estimates of aboveground dry biomass for different types of land cover in each county or state were converted directly to estimates of standing carbon. A portable, inexpensive laser that measures forest canopy height and canopy cover was also used to identify and map mature forest stands that might support the Delmarva fox squirrel (Sciurus niger cinereus), an endangered species. Merchantable volume estimates were within 24 percent of US Forest Service estimates at the county level and within 15 percent statewide. Total aboveground dry biomass estimates were within 19 percent of US Forest Service estimates at the county level and within 16 percent statewide. Various types of impervious surfaces (roofs, concrete, asphalt) and open water were tallied along the fight lines to estimate a real coverage statewide, by land cover and county. Laser estimates of impervious surface area were within 28 percent of satellite-based estimates at the county level and within 3 percent at the state level. Laser estimates of open water were within 7 percent of photointerpreted geographic information system (GIS) estimates at the county level and within 3 percent of the GIS at the state level. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Delaware Forest Serv, Dover, DE 19901 USA. US Fish & Wildlife Serv, Chesapeake Bay Field Off, Annapolis, MD 21401 USA. RP Nelson, R (reprint author), NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Code 923, Greenbelt, MD 20771 USA. RI Nelson, Ross/H-8266-2014 NR 48 TC 60 Z9 63 U1 0 U2 4 PU AMER INST BIOLOGICAL SCI PI WASHINGTON PA 1444 EYE ST, NW, STE 200, WASHINGTON, DC 20005 USA SN 0006-3568 J9 BIOSCIENCE JI Bioscience PD OCT PY 2003 VL 53 IS 10 BP 981 EP 992 DI 10.1641/0006-3568(2003)053[0981:AMRIOD]2.0.CO;2 PG 12 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 730EK UT WOS:000185816100011 ER PT J AU Popescu, SC Wynne, RH Nelson, RF AF Popescu, SC Wynne, RH Nelson, RF TI Measuring individual tree crown diameter with lidar and assessing its influence on estimating forest volume and biomass SO CANADIAN JOURNAL OF REMOTE SENSING LA English DT Article; Proceedings Paper CT Workshop on 3-D Analysis of Forest Structure and Terrain Using LiDAR Technology CY MAR, 2002 CL VICTORIA, CANADA ID LASER SCANNER DATA; STAND CHARACTERISTICS; RESOLUTION IMAGERY; BASAL AREA; CANOPY; HEIGHTS; ALTIMETER AB The main objective of this study was to develop reliable processing and analysis techniques to facilitate the use of small-footprint lidar data for estimating tree crown diameter by measuring individual trees identifiable on the three-dimensional lidar surface. In addition, the study explored the importance of the lidar-derived crown diameter for estimating tree volume and biomass. The lidar dataset was acquired over deciduous, coniferous, and mixed stands of varying age classes and settings typical of the southeastern United States. For identifying individual trees, lidar processing techniques used data fusion with multispectral optical data and local filtering with both square and circular windows of variable size. The crown diameter was calculated as the average of two values measured along two perpendicular directions from the location of each tree top by fitting a fourth-degree polynomial on both profiles. The lidar-derived tree measurements were used with regression models and cross-validation to estimate plot level field-measured crown diameter. Linear regression was also used to compare plot level tree volume and biomass estimation with and without lidar-derived crown diameter measures from individual trees. Results for estimating crown diameter were similar for both pines and deciduous trees, with R-2 values of 0.62-0.63 for the dominant trees (root mean square error (RMSE) 1.36 to 1.41 m). Lidar-measured crown diameter improved R 2 values for volume and biomass estimation by up to 0.25 for both pines and deciduous plots (RMSE improved by up to 8 m(3)/ha for volume and 7 Mg/ha for biomass). For the pine plots, average crown diameter alone explained 78% of the variance associated with biomass (RMSE 31.28 Mg/ha) and 83% of the variance for volume (RMSE 47.90 m(3)/ha). C1 Virginia Tech, Dept Forestry, Blacksburg, VA 24061 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Popescu, SC (reprint author), Texas A&M Univ, Dept Forest Sci, Spatial Sci Lab, 1500 Res Pkwy,Suite B223, College Stn, TX 77845 USA. RI Popescu, Sorin/D-5981-2015; Nelson, Ross/H-8266-2014 OI Popescu, Sorin/0000-0002-8155-8801; NR 52 TC 307 Z9 315 U1 7 U2 72 PU CANADIAN AERONAUTICS SPACE INST PI OTTAWA PA 1685 RUSSELL RD, UNIT 1-R, OTTAWA, ON K1G 0N1, CANADA SN 0703-8992 J9 CAN J REMOTE SENS JI Can. J. Remote Sens. PD OCT PY 2003 VL 29 IS 5 BP 564 EP 577 PG 14 WC Remote Sensing SC Remote Sensing GA 738YA UT WOS:000186314400006 ER PT J AU Toutanji, H Matthewson, PR Effinger, A Noumowe, A AF Toutanji, H Matthewson, PR Effinger, A Noumowe, A TI Zero-eccentricity direct-tension testing of thermally damaged cement-based materials SO CEMENT AND CONCRETE RESEARCH LA English DT Article DE high temperature; mortar; silica fume; stiffness; tensile properties ID SILICA FUME CONCRETE; HIGH-TEMPERATURE; FLY-ASH; STRENGTH AB This study presents some results on direct-tension strength of two cementitious mortars using a test set-up specifically designed to virtually eliminate any load eccentricity. The tests were conducted on cement mortars with and without condensed silica fume after being exposed to high temperature (200, 300, 400 and 500 degreesC). Direct-tension tests were also carried out at room temperature (20 degreesC) for reference. The specimens were exposed to high temperature and were then allowed to cool to room temperature before testing up to failure. The strength values measured in this study exhibit a trend that is similar to that exhibited by the compressive strength cited in the literature. The results show that mortar specimens exhibited a small increase in strength at temperatures up to 200 degreesC for regular mortar and up to 230 degreesC for silica fume mortar. At temperatures above 200/230 degreesC, the residual tensile strength of the mortar decreases significantly and rapidly. Adding silica fume to the cement mortar increases the resistance to high temperature. (C) 2003 Elsevier Ltd. All rights reserved. C1 Univ Alabama, Dept Civil & Environm Engn, Huntsville, AL 35899 USA. NASA, George C Marshall Space Flight Ctr, Mat Proc & Mfg Dept, Huntsville, AL 35812 USA. Univ Cergy Pontoise, Dept Civil Engn, Cergy Pontoise, France. RP Toutanji, H (reprint author), Univ Alabama, Dept Civil & Environm Engn, S241 Technol Dr, Huntsville, AL 35899 USA. EM toutanji@cee.uah.edu RI Chen, Wei/A-5694-2010 NR 16 TC 2 Z9 2 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0008-8846 J9 CEMENT CONCRETE RES JI Cem. Concr. Res. PD OCT PY 2003 VL 33 IS 10 BP 1507 EP 1513 DI 10.1016/S0008-8846(03)00126-1 PG 7 WC Construction & Building Technology; Materials Science, Multidisciplinary SC Construction & Building Technology; Materials Science GA 807GB UT WOS:000220488900002 ER PT J AU Dong, HL Kostka, JE Kim, J AF Dong, HL Kostka, JE Kim, J TI Microscopic evidence for microbial dissolution of smectite SO CLAYS AND CLAY MINERALS LA English DT Article DE EC-TEM; microbial Fe(III) reduction; mineral transformation; Shewanella oneidensis; smectite ID FE(III) OXIDE REDUCTION; IRON OXIDATION-STATE; BACTERIAL REDUCTION; STRUCTURAL FE(III); HUMIC SUBSTANCES; CLAY-MINERALS; SURFACE-AREA; FERRIC-OXIDE; NONTRONITE; MAGNETITE AB This study was undertaken to investigate mechanisms of mineral transformations associated with microbial reduction of structural Fe(III) in smectite. Shewanella oneidensis strain MR-1 cells were inoculated with lactate as the electron donor and Fe(III) in smectite as the electron acceptor. The extent of Fe(III) reduction was observed to reach up to 26%. Reduction proceeded via association of live bacterial cells with smectite. At the end of incubation, a large fraction of starting smectite was transformed to euhedral flakes of biogenic smectite with different morphology, structure, and composition. Lattice-fringe images obtained from environmental cell transmission electron microscope displayed a decrease of layer spacing from 1.5 +/- 0.1 nm for the unreduced smectite to 1.1+/-0.1 nm for the reduced smectite. The biogenic smectite contained more abundant interlayer cations, apparently as a result of charge compensation for the reduced oxidation state of Fe in the octahedral site. To capture the dynamics of smectite reduction, a separate experiment was designed. The experiment consisted of several systems, where various combinations of carbon source (lactate) and different concentrations of AQDS, an electron shuttle, were used. Selected area electron diffraction patterns of smectite showed progressive change from single-crystal patterns for the control experiment (oxidized, unaltered smectite), to diffuse ring patterns for the no-carbon experiment (oxidized, but altered smectite), to well-ordered single crystal pattern for the experiment amended with 1 mM AQDS (well crystalline, biogenic smectite). Large crystals of vivianite and fine-grained silica of biogenic origin were also detected in the bioreduced sample. These data collectively demonstrate that microbial reduction of Fe(III) in smectite was achieved via dissolution of smectite and formation of biogenic minerals. The microbially mediated mineral dissolution-precipitation mechanism has important implications for mineral reactions in natural environments, where the reaction rates may be substantially enhanced by the presence of bacteria. C1 Miami Univ, Dept Geol, Oxford, OH 45056 USA. Florida State Univ, Dept Oceanog, Tallahassee, FL 32306 USA. NASA, Naval Res Lab, Stennis Space Ctr, MS 39529 USA. RP Dong, HL (reprint author), Miami Univ, Dept Geol, Oxford, OH 45056 USA. NR 36 TC 29 Z9 31 U1 1 U2 29 PU CLAY MINERALS SOCIETY PI AURORA PA PO BOX 460130, AURORA, CO 80046-0130 USA SN 0009-8604 J9 CLAY CLAY MINER JI Clay Clay Min. PD OCT PY 2003 VL 51 IS 5 BP 502 EP 512 DI 10.1346/CCMN.2003.0510504 PG 11 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy; Soil Science SC Chemistry; Geology; Mineralogy; Agriculture GA 731HQ UT WOS:000185878600004 ER PT J AU Vaughan, DG Marshall, GJ Connolley, WM Parkinson, C Mulvaney, R Hodgson, DA King, JC Pudsey, CJ Turner, J AF Vaughan, DG Marshall, GJ Connolley, WM Parkinson, C Mulvaney, R Hodgson, DA King, JC Pudsey, CJ Turner, J TI Recent rapid regional climate warming on the Antarctic Peninsula SO CLIMATIC CHANGE LA English DT Review ID LARSEN ICE SHELF; NCEP-NCAR REANALYSIS; SEA-ICE; SOUTHERN-OCEAN; TEMPERATURE TRENDS; SURFACE TEMPERATURES; AIR-TEMPERATURE; SEMIANNUAL OSCILLATION; BELLINGSHAUSEN SEAS; VASCULAR PLANTS AB The Intergovernmental Panel on Climate Change (IPCC) confirmed that mean global warming was 0.6 +/- 0.2degreesC during the 20th century and cited anthropogenic increases in greenhouse gases as the likely cause of temperature rise in the last 50 years. But this mean value conceals the substantial complexity of observed climate change, which is seasonally- and diurnally-biased, decadally-variable and geographically patchy. In particular, over the last 50 years three high-latitude areas have undergone recent rapid regional (RRR) warming, which was substantially more rapid than the global mean. However, each RRR warming occupies a different climatic regime and may have an entirely different underlying cause. We discuss the significance of RRR warming in one area, the Antarctic Peninsula. Here warming was much more rapid than in the rest of Antarctica where it was not significantly different to the global mean. We highlight climate proxies that appear to show that RRR warming on the Antarctic Peninsula is unprecedented over the last two millennia, and so unlikely to be a natural mode of variability. So while the station records do not indicate a ubiquitous polar amplification of global warming, the RRR warming on the Antarctic Peninsula might be a regional amplification of such warming. This, however, remains unproven since we cannot yet be sure what mechanism leads to such an amplification. We discuss several possible candidate mechanisms: changing oceanographic or changing atmospheric circulation, or a regional air-sea-ice feedback amplifying greenhouse warming. We can show that atmospheric warming and reduction in sea-ice duration coincide in a small area on the west of the Antarctic Peninsula, but here we cannot yet distinguish cause and effect. Thus for the present we cannot determine which process is the probable cause of RRR warming on the Antarctic Peninsula and until the mechanism initiating and sustaining the RRR warming is understood, and is convincingly reproduced in climate models, we lack a sound basis for predicting climate change in this region over the coming century. C1 British Antarctic Survey, NERC, Cambridge CB3 0ET, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Vaughan, DG (reprint author), British Antarctic Survey, NERC, Madingley Rd, Cambridge CB3 0ET, England. RI Parkinson, Claire/E-1747-2012; Vaughan, David/C-8348-2011; Mulvaney, Robert/K-3929-2012 OI Parkinson, Claire/0000-0001-6730-4197; Mulvaney, Robert/0000-0002-5372-8148 NR 121 TC 500 Z9 515 U1 25 U2 183 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0165-0009 EI 1573-1480 J9 CLIMATIC CHANGE JI Clim. Change PD OCT PY 2003 VL 60 IS 3 BP 243 EP 274 DI 10.1023/A:1026021217991 PG 32 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 729VW UT WOS:000185796600002 ER PT J AU Frank, J Jonsson, A AF Frank, J Jonsson, A TI Constraint-based attribute and interval planning SO CONSTRAINTS LA English DT Article DE planning; dynamic constraint reasoning; consistency enforcement; temporal planning; resources AB In this paper we describe Constraint-based Attribute and Interval Planning (CAIP), a paradigm for representing and reasoning about plans. The paradigm enables the description of planning domains with time, resources, concurrent activities, mutual exclusions among sets of activities, disjunctive preconditions and conditional effects. We provide a theoretical foundation for the paradigm, based on temporal intervals and attributes. We show how the plans are naturally expressed by networks of constraints, and show that the process of planning maps directly to dynamic constraint reasoning. We describe compatibilities, a compact mechanism for describing planning domains. We also demonstrate how this framework incorporates the use of constraint representation and reasoning technology to improve planning. Finally, we describe EUROPA, an implementation of the CAIP framework. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Frank, J (reprint author), NASA, Ames Res Ctr, Mail Stop N269-3, Moffett Field, CA 94035 USA. EM frank@email.arc.nasa.gov; jonsson@email.arc.nasa.gov NR 23 TC 54 Z9 54 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1383-7133 J9 CONSTRAINTS JI Constraints PD OCT PY 2003 VL 8 IS 4 BP 339 EP 364 DI 10.1023/A:1025842019552 PG 26 WC Computer Science, Artificial Intelligence; Computer Science, Theory & Methods SC Computer Science GA 803WM UT WOS:000220261200002 ER PT J AU Mironov, AA Mironov, AA Beznoussenko, GV Trucco, A Lupetti, P Smith, JD Geerts, WJC Koster, AJ Burger, KNJ Martone, ME Deerinck, TJ Ellisman, MH Luini, A AF Mironov, AA Mironov, AA Beznoussenko, GV Trucco, A Lupetti, P Smith, JD Geerts, WJC Koster, AJ Burger, KNJ Martone, ME Deerinck, TJ Ellisman, MH Luini, A TI ER-to-golgi carriers arise through direct en bloc protrusion and multistage maturation of specialized ER exit domains SO DEVELOPMENTAL CELL LA English DT Article ID ENDOPLASMIC-RETICULUM; INTERMEDIATE COMPARTMENT; CARGO SELECTION; LIVING CELLS; TRANSPORT; COPII; DYNAMICS; EXPORT; PROTEINS; COMPLEX AB Protein transport between the ER and the Golgi in mammalian cells occurs via large pleiomorphic carriers, and most current models suggest that these are formed by the fusion of small ER-derived COPII vesicles. We have examined the dynamics and structural features of these carriers during and after their formation from the ER by correlative video/light electron microscopy and tomography. We found that saccular carriers containing either the large supramolecular cargo procollagen or the small diffusible cargo protein VSVG arise through cargo concentration and direct en bloc protrusion of specialized ER domains in the vicinity of COPII-coated exit sites. This formation process is COPII dependent but does not involve budding and fusion of COPII-dependent vesicles. Fully protruded saccules then move centripetally, evolving into one of two types of carriers (with distinct kinetic and structural features). These findings provide an alternative framework for analysis of ER-to-Golgi traffic. C1 Ist Ric Farmacol Mario Negri, Consorzio Mario Negri Sud, Dept Cell Biol & Oncol, I-66030 Santa Maria Imbaro, Chieti, Italy. Univ Siena, Dipartimento Biol Evolut, I-53100 Siena, Italy. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Utrecht, Inst Biomembranes, Dept Mol Cell Biol, NL-3584 CX Utrecht, Netherlands. Univ Calif San Diego, Natl Ctr Microscopy & Imaging Res, La Jolla, CA 92037 USA. RP Luini, A (reprint author), Ist Ric Farmacol Mario Negri, Consorzio Mario Negri Sud, Dept Cell Biol & Oncol, I-66030 Santa Maria Imbaro, Chieti, Italy. EM luini@negrisud.it RI Geerts, Willie /B-7640-2011; LUPETTI, PIETRO/G-7699-2011; Luini, Alberto/L-1372-2013; OI Luini, Alberto/0000-0002-8729-2549; Lupetti, Pietro/0000-0003-4316-9861 FU Telethon [E.0982] NR 32 TC 140 Z9 149 U1 0 U2 7 PU CELL PRESS PI CAMBRIDGE PA 600 TECHNOLOGY SQUARE, 5TH FLOOR, CAMBRIDGE, MA 02139 USA SN 1534-5807 J9 DEV CELL JI Dev. Cell PD OCT PY 2003 VL 5 IS 4 BP 583 EP 594 DI 10.1016/S1534-5807(03)00294-6 PG 12 WC Cell Biology; Developmental Biology SC Cell Biology; Developmental Biology GA 731ED UT WOS:000185870800012 PM 14536060 ER PT J AU Zhu, S Su, CH Lehoczky, SL Muntele, I Ila, D AF Zhu, S Su, CH Lehoczky, SL Muntele, I Ila, D TI Carbon nanotube growth on carbon fibers SO DIAMOND AND RELATED MATERIALS LA English DT Article; Proceedings Paper CT 8th International Conference on New Diamond Science and Technology CY JUL 21-26, 2002 CL VICTORIA, AUSTRALIA DE low dimensional structure; chemical vapor deposition processes; nanomaterials ID CHEMICAL-VAPOR-DEPOSITION; TEMPERATURE; DIAMETER; DIAMOND AB Carbon nanotubes (CNT) were synthesized on graphite fibers by thermal CVD. On the fiber surface, iron nanoparticles are coated and act as catalysts for CNT growth. The growth temperature ranges from 550 to 1000 degreesC at an ambient pressure. Methane and hydrogen gases with methane contents of 10-100% are used for the CNT synthesis. At high growth temperatures (>800 degreesC), the rapid inter-diffusion of the transition metal iron on the graphite surface results in a rough fiber surface with no CNT grown on the surface. When the growth temperature is relatively low (650-800 degreesC), CNT are fabricated on the graphite surface with catalytic particles on the nanotube top ends. Using micro Raman spectroscopy in the breath mode region, single-walled or multi-walled CNT can be determined, depending on methane concentrations. (C) 2003 Elsevier B.V. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, Huntsville, AL 35812 USA. NASA, George C Marshall Space Flight Ctr, Sci Directorate, Micrograv Sci & Applicat Dept, Huntsville, AL 35812 USA. Alabama A&M Univ, Ctr Irradiat Mat, Normal, AL 35762 USA. RP Zhu, S (reprint author), NASA, George C Marshall Space Flight Ctr, Univ Space Res Assoc, 11 Mohovaya St, Huntsville, AL 35812 USA. NR 15 TC 110 Z9 115 U1 5 U2 32 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-9635 J9 DIAM RELAT MATER JI Diam. Relat. Mat. PD OCT-NOV PY 2003 VL 12 IS 10-11 BP 1825 EP 1828 DI 10.1016/S0925-9635(03)00205-X PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 755TJ UT WOS:000187427300037 ER PT J AU Lux, JR Davidson, BD AF Lux, JR Davidson, BD TI Guidelines for the development of computer-based instruction modules for science and engineering SO EDUCATIONAL TECHNOLOGY & SOCIETY LA English DT Article DE CBI; learning object; engineering education; statics; structures; structural analysis; strength of materials; problem-solving; Macromedia Authorware AB The design and development of a prototype computer-based instruction ( CBI) module is described. The module covers introductory structural analysis techniques and demonstrates the practicality of CBI for undergraduate engineering education. The module's generic learning objectives are used to develop a set of guiding principles for CBI development. Choice of authoring software and the module architecture are presented, followed by the details of the user interface, logic, and screen layout. The module design and software development process outlined here are easily extended to computer-based tutorials that present problem solving methods for engineering, mathematics, and the natural sciences. C1 NASA, Dryden Flight Res Ctr, Edwards AFB, CA 93523 USA. Syracuse Univ, Dept Mech Aerosp & Mfg Engn, Syracuse, NY 13244 USA. RP Lux, JR (reprint author), NASA, Dryden Flight Res Ctr, POB 273,MS 3302, Edwards AFB, CA 93523 USA. EM jessica.r.lux@nasa.gov; bddavids@syr.edu NR 14 TC 2 Z9 2 U1 0 U2 1 PU IEEE COMPUTER SOC, LEARNING TECHNOLOGY TASK FORCE PI PALMERSTON NORTH PA BAG 11-222, MASSEY UNIVERSITY, PALMERSTON NORTH, NEW ZEALAND SN 1436-4522 J9 EDUC TECHNOL SOC JI Educ. Technol. Soc. PD OCT PY 2003 VL 6 IS 4 BP 125 EP 133 PG 9 WC Education & Educational Research SC Education & Educational Research GA 777AQ UT WOS:000189152100012 ER PT J AU Forth, SC Favrow, LH Keat, WD Newman, JA AF Forth, SC Favrow, LH Keat, WD Newman, JA TI Three-dimensional mixed-mode fatigue crack growth in a functionally graded titanium alloy SO ENGINEERING FRACTURE MECHANICS LA English DT Article DE functionally graded; titanium; fatigue crack growth; mixed-mode ID SURFACE INTEGRAL METHOD; TI-6AL-4V AB The implementation of unitized structure in the aerospace industry has resulted in complex geometries and load paths. Hence, structural failure due to three-dimensional mixed-mode fatigue crack growth is a mounting concern. In addition, the development of functionally graded materials has further complicated structural integrity issues by intentionally introducing material variability to create desirable mechanical behavior. Ti-6Al-4V beta-STOA (solution treated over-aged) titanium is a functionally graded metallic alloy that has been tailored for superior fatigue crack growth and fracture response compared with traditional titanium alloys. Specifically, the near-surface material of Ti beta-STOA is resistant to fatigue crack incubation and the interior is more resistant to fatigue crack growth and fracture. Therefore, Ti beta-STOA is well suited for applications where surface cracking is a known failure mode. Advances in experimental testing have shown that complex loading conditions and multi-faceted materials can be tested reliably. In this paper, the authors will experimentally generate three-dimensional mixed-mode surface crack data in functionally graded Ti-6Al-4V beta-STOA and comment on the effect of the material tailoring. Published by Elsevier Ltd. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Pratt & Whitney Aircraft, E Hartford, CT USA. Union Coll, Dept Mech Engn, Schenectady, NY 12308 USA. USA, Res Lab, Vehicle Technol Directorate, Hampton, VA USA. RP Forth, SC (reprint author), NASA, Langley Res Ctr, MS 188E,2 W Reid St, Hampton, VA 23681 USA. NR 19 TC 17 Z9 17 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0013-7944 J9 ENG FRACT MECH JI Eng. Fract. Mech. PD OCT PY 2003 VL 70 IS 15 BP 2175 EP 2185 DI 10.1016/S0013-7944(02)00237-0 PG 11 WC Mechanics SC Mechanics GA 705EX UT WOS:000184383700012 ER PT J AU La Duc, MT Nicholson, W Kern, R Venkateswaran, K AF La Duc, MT Nicholson, W Kern, R Venkateswaran, K TI Microbial characterization of the Mars Odyssey spacecraft and its encapsulation facility SO ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID MICROBIOLOGICAL PROFILES; RESISTANCE AB Microbial characterization of the Mars Odyssey spacecraft and the Kennedy Space Center Spacecraft Assembly and Encapsulation Facility II (SAEF-II) was carried out by both culture-based and molecular methods. The most dominant cultivable microbes were species of Bacillus, with comamonads, microbacteria and actinomycetales also represented. Several spore-forming isolates were resistant to gamma-radiation, UV, H2O2 and desiccation, and one Acinetobacter radioresistens isolate and several Aureobasidium, isolated directly from the spacecraft, survived various conditions. Sequences arising in clone libraries were fairly consistent between the spacecraft and facility; predominant genera included Variovorax, Ralstonia and Aquaspirillum. This study improves our understanding of the microbial community structure, diversity and survival capabilities of microbes in an encapsulation facility and physically associated with colocated spacecraft. C1 CALTECH, Jet Prop Lab, NASA, Biotechnol & Planetary Protect Grp, Pasadena, CA 91109 USA. Univ Arizona, Dept Vet Sci & Microbiol, Tucson, AZ 85721 USA. RP La Duc, MT (reprint author), CALTECH, Jet Prop Lab, NASA, Biotechnol & Planetary Protect Grp, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 25 TC 100 Z9 101 U1 0 U2 7 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 1462-2912 J9 ENVIRON MICROBIOL JI Environ. Microbiol. PD OCT PY 2003 VL 5 IS 10 BP 977 EP 985 DI 10.1046/j.1462-2920.2003.00496.x PG 9 WC Microbiology SC Microbiology GA 728YG UT WOS:000185743500017 PM 14510851 ER PT J AU Tester, PA Varnam, SM Culver, ME Eslinger, DL Stumpf, RP Swift, RN Yungel, JK Black, MD Litaker, RW AF Tester, PA Varnam, SM Culver, ME Eslinger, DL Stumpf, RP Swift, RN Yungel, JK Black, MD Litaker, RW TI Airborne detection of ecosystem responses to an extreme event: Phytoplankton displacement and abundance after hurricane induced flooding in the Pamlico-Albemarle Sound system, North Carolina SO ESTUARIES LA English DT Article ID NEUSE RIVER ESTUARY; INTENSE ATLANTIC HURRICANES; DISSOLVED ORGANIC-MATTER; ABSORPTION-COEFFICIENT; COMMUNITY-STRUCTURE; LAGOONAL ESTUARY; BLOOM; FLUORESCENCE; RETRIEVAL; SATELLITE AB Airborne laser-induced fluorescence measurements were used to detect and monitor ecosystem wide changes in the distribution and concentration of chlorophyll biomass and colored dissolved organic matter in the Pamlico-Albemarle Sound system, North Carolina, U.S., following massive flooding caused by a series of three hurricanes in the late summer of 1999. These high-resolution data provided a significantly more detailed representation of the overall changes occurring in the system than could have been achieved by synoptic sampling from any other platform. The response time for the distribution of chlorophyll biomass to resume pre-flood conditions was used as a measure of ecosystem stability. Chlorophyll biomass patterns were reestablished within four mo of the flooding, whereas higher chlorophyll a biomass concentrations persisted for approximately 6 mo. The primary trophic level in the Pamlico-Albemarle Sound system returned to equilibrium in less than a year of a major perturbation. C1 NOAA, Natl Ocean Serv, Ctr Coastal Fisheries & Habitat Res, Beaufort, NC 28516 USA. NOAA, Natl Ocean Serv, Coastal Serv Ctr, Charleston, SC 29405 USA. NOAA, Natl Ocean Serv, Ctr Coastal Monitoring & Assessment, Silver Spring, MD 20910 USA. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. NASA, Goddard Space Flight Ctr, EG&G, Wallops Flight Facil, Wallops Isl, VA 23337 USA. RP Tester, PA (reprint author), NOAA, Natl Ocean Serv, Ctr Coastal Fisheries & Habitat Res, 101 Pivers Isl Rd, Beaufort, NC 28516 USA. EM pat.tester@noaa.gov RI Black, Megan/G-6410-2016; OI Black, Megan/0000-0001-5511-1419 NR 43 TC 17 Z9 18 U1 0 U2 7 PU ESTUARINE RESEARCH FEDERATION PI PORT REPUBLIC PA 2018 DAFFODIL, PO BOX 510, PORT REPUBLIC, MD 20676 USA SN 0160-8347 J9 ESTUARIES JI Estuaries PD OCT PY 2003 VL 26 IS 5 BP 1353 EP 1364 DI 10.1007/BF02803637 PG 12 WC Environmental Sciences; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA 756JY UT WOS:000187463000013 ER PT J AU Vahdat, N Zou, Y Collins, M AF Vahdat, N Zou, Y Collins, M TI Fire-extinguishing effectiveness of new binary agents SO FIRE SAFETY JOURNAL LA English DT Article DE inert gas suppressants; halogenated suppressants; binary agents; prediction of extinguishing concentrations; synergism ID INHIBITION EFFECTIVENESS; SUPPRESSANTS AB The search for a new fire-extinguishing agent with all the desirable properties of halon 1301 has not been successful. During the last few years, several chemical groups with very low extinguishing concentrations have been identified. Most of these compounds have high boiling points and are not suitable replacements for halon 1301. However, mixtures of these chemicals in an inert gas could produce fire-extinguishing agents with many of the desirable properties of halon 1301. To study binary fire suppressants, one has to determine the extinguishing concentrations for several compositions of a given chemical in an inert gas. This process is expensive and time consuming. A method to estimate the extinguishing concentrations would be helpful in reducing the number of experiments needed for any binary system. In this study, a method based on adiabatic flame temperature calculations and the dependence of the rate of fire suppression of chemical agents on temperature was used to estimate the extinguishing concentration of binary mixtures. The method was tested for five organic compound/nitrogen mixtures. Five compounds that have been shown to have very low extinguishing concentrations and very short atmospheric lifetime were selected for this study. Cup burner experiments were conducted for several concentrations of each chemical in nitrogen. All the five binary systems showed synergism. As expected, the degree of synergism was highest at low concentrations of the chemical. For each binary system, extinguishing concentrations of the pure compounds and one binary data were used to predict the extinguishing concentrations for the entire range of binary composition. The predicted values are very close to experimental data. Published by Elsevier Science Ltd. C1 Tuskegee Univ, Dept Chem Engn, Sch Engn, Tuskegee, AL 36088 USA. NASA, Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. RP Vahdat, N (reprint author), Tuskegee Univ, Dept Chem Engn, Sch Engn, Tuskegee, AL 36088 USA. NR 18 TC 9 Z9 9 U1 1 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0379-7112 J9 FIRE SAFETY J JI Fire Saf. J. PD OCT PY 2003 VL 38 IS 6 BP 553 EP 567 DI 10.1016/S0379-7112(03)00013-4 PG 15 WC Engineering, Civil; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 709ZP UT WOS:000184656700003 ER PT J AU Fulling, GL Mullin, KD Hubard, CW AF Fulling, GL Mullin, KD Hubard, CW TI Abundance and distribution of cetaceans in outer continental shelf waters of the US Gulf of Mexico SO FISHERY BULLETIN LA English DT Article ID WEST FLORIDA SHELF; DOLPHIN; AERIAL C1 NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, Pascagoula, MS 39567 USA. RP Fulling, GL (reprint author), NOAA, Natl Marine Fisheries Serv, SE Fisheries Sci Ctr, 3209 Frederic St, Pascagoula, MS 39567 USA. NR 35 TC 18 Z9 23 U1 0 U2 3 PU NATL MARINE FISHERIES SERVICE SCIENTIFIC PUBL OFFICE PI SEATTLE PA 7600 SAND POINT WAY NE BIN C15700, SEATTLE, WA 98115 USA SN 0090-0656 J9 FISH B-NOAA JI Fish. Bull. PD OCT PY 2003 VL 101 IS 4 BP 923 EP 932 PG 10 WC Fisheries SC Fisheries GA 746FE UT WOS:000186735700020 ER PT J AU Cakir, Z de Chabalier, JB Armijo, R Meyer, B Barka, A Peltzer, G AF Cakir, Z de Chabalier, JB Armijo, R Meyer, B Barka, A Peltzer, G TI Coseismic and early post-seismic slip associated with the 1999 Izmit earthquake (Turkey), from SAR interferometry and tectonic field observations SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE Izmit earthquake slip; coseismic; post-seismic deformation; InSAR ID NORTH ANATOLIAN FAULT; RADAR INTERFEROMETRY; SURFACE RUPTURE; AUGUST 17; LANDERS EARTHQUAKE; DUZCE EARTHQUAKES; JOINT INVERSION; SEISMIC HAZARD; ACTIVE FAULTS; MARMARA SEA AB We use combined tectonic field observations and SAR data to determine an improved model of the slip associated with the 1999 Izmit earthquake, which ruptured the North Anatolian Fault at the eastern end of the Sea of Marmara. The leading goal is to understand the main features of the coseismic and post-seismic deformation, which are captured together in the SAR data. To achieve this, we make a critical analysis of the ERS1-2 SAR data, which allows atmospheric effects to be identified and removed. We also use detailed field mapping and measurements of the earthquake surface rupture. Dislocations in elastic half-space and a forward modelling strategy allow us to obtain a slip model by steps. A trial-and-error approach is combined with conventional inversion techniques to determine the slip in the different regions of the fault. The SAR data are well explained with three main zones of high slip along the fault, releasing a total moment of 2.3 x 10(20) N m (M-w = 7.6), which is higher than the seismological estimates (1.7-2.0 x 10(20) N m). The inhomogeneous slip distribution correlates with fault segments identified at the surface. The Izmit rupture appears to have extended 30 km west of the Hersek peninsula into the Sea of Marmara with slip tapering from 2 m to zero. The western end of the rupture is located 40 km SSE from Istanbul. We show that some features seen near to Mudurnu and Gevye and previously interpreted as slip on secondary faults are explained mostly as atmospheric effects correlated with the topography. Using our approach and the available GPS data we obtain a slip model that represents the coseismic slip alone, which suggests that the moment release during the main shock was 1.9 x 10(20) N m (M-w = 7.5), consistent with the seismological estimates. We conclude that the SAR data include the effects of 2 m of fast after-slip during the month following the main shock, within a zone of the fault located 1224 km below the epicentral region. Near the hypocentre at a depth of 18 km, the fault appears to have experienced dynamic slip of 1 m associated with the main shock, followed by 2 m of rapidly decelerating post-seismic shear during the following month. We suggest that the distribution of heterogeneous slip and loading along the different fault segments may be important factors controlling the propagation of large earthquake ruptures along the North Anatolian Fault. C1 ITU, Istanbul, Turkey. CNRS, IPGP, UMR 1578 7580, Paris, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cakir, Z (reprint author), Inst Phys Globe Strasbourg, F-67084 Strasbourg, France. EM cakirz@itu.edu.tr RI Cakir, Ziyadin/C-3594-2008; Armijo, Rolando/A-5715-2011; Meyer, Bertrand/E-6903-2011; de Chabalier, Jean-Bernard/F-1737-2017 OI Cakir, Ziyadin/0000-0003-3050-5619; de Chabalier, Jean-Bernard/0000-0002-5021-6702 NR 60 TC 76 Z9 79 U1 2 U2 7 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD OCT PY 2003 VL 155 IS 1 BP 93 EP 110 DI 10.1046/j.1365-246X.2003.02001.x PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 721ZH UT WOS:000185348000009 ER PT J AU Schuerger, AC Mancinelli, RL Kern, RG Rothschild, LJ McKay, CP AF Schuerger, AC Mancinelli, RL Kern, RG Rothschild, LJ McKay, CP TI Survival of endospores of Bacillus subtilis on spacecraft surfaces under simulated martian environments: implications for the forward contamination of Mars SO ICARUS LA English DT Article DE Mars; exobiology; spectroscopy; regoliths; ultraviolet observations ID HAWAIIAN PALAGONITIC SOIL; SOLAR-RADIATION; BACTERIAL-SPORES; TERRESTRIAL MICROORGANISMS; BIOLOGICAL CONTAMINATION; MICROBIOLOGICAL PROFILES; ULTRAVIOLET-IRRADIATION; MAGNETIC-PROPERTIES; VIKING SPACECRAFT; ATMOSPHERIC DUST AB Experiments were conducted in a Mars simulation chamber (MSC) to characterize the survival of endospores of Bacillus subtilis under high UV irradiation and simulated martian conditions. The MSC was used to create Mars surface environments in which pressure (8.5 mb), temperature (-80, -40, -10, or +23 degreesC, gas composition (Earth-normal N-2 /O-2 mix, pure N-2, pure CO2, or a Mars gas mix), and UV-VIS-NIR fluence rates (200-1200 nm) were maintained within tight limits. The Mars gas mix was composed of CO2 (95.3%), N-2 (2.7%), At (1.7%), O-2 (0.2%), and water vapor (0.03%). Experiments were conducted to measure the effects of pressure, gas composition, and temperature alone or in combination with Mars-normal UV-VIS-NIR light environments. Endospores of B. subtilis, were deposited on aluminum coupons as monolayers in which the average density applied to coupons was 2.47 x 10(6) bacteria per sample. Populations of B. subtilis placed on aluminum coupons and subjected to an Earth-normal temperature (23 degreesC, pressure (1013 mb), and gas mix (normal N-2/O-2 ratio) but illuminated with a Mars-normal UV-VIS-NIR spectrum were reduced by over 99.9% after 30 see exposure to Mars-normal UV fluence rates. However, it required at least 15 min of Mars-normal UV exposure to reduce bacterial populations on aluminum coupons to non-recoverable levels. These results were duplicated when bacteria were exposed to Mars-normal environments of temperature (-10 degreesC, pressure (8.5 mb), gas composition (pure CO2), and UV fluence rates. In other experiments, results indicated that the gas composition of the atmosphere and the temperature of the bacterial monolayers at the time of Mars UV exposure had no effects on the survival of bacterial endospores. But Mars-normal pressures (8.5 mb) were found to reduce survival by approximately 20-35% compared to Earth-normal pressures (1013 mb). The primary implications of these results are (a) that greater than 99.9% of bacterial populations on sun-exposed surfaces of spacecraft are likely to be inactivated within a few tens of seconds to a few minutes on the surface of Mars, and (b) that within a single Mars day under clear-sky conditions bacterial populations on sun-exposed surfaces of spacecraft will be sterilized. Furthermore, these results suggest that the high UV fluence rates on the martian surface can be an important resource in minimizing the forward contamination of Mars. (C) 2003 Elsevier Inc. All rights reserved. C1 Dynamac Corp, Kennedy Space Ctr, FL 32899 USA. NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. CALTECH, Jet Prop Lab, Mars Explorat Directorate, Pasadena, CA 91109 USA. NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Schuerger, AC (reprint author), Dynamac Corp, Mail Code DYN-3, Kennedy Space Ctr, FL 32899 USA. EM schueac@kscems.ksc.nasa.gov RI Mancinelli, Rocco/L-8971-2016 NR 86 TC 109 Z9 110 U1 2 U2 25 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 EI 1090-2643 J9 ICARUS JI Icarus PD OCT PY 2003 VL 165 IS 2 BP 253 EP 276 DI 10.1016/S0019-1035(03)00200-8 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 729BZ UT WOS:000185752300003 PM 14649627 ER PT J AU Catling, DC Moore, JA AF Catling, DC Moore, JA TI The nature of coarse-grained crystalline hematite and its implications for the early environment of Mars SO ICARUS LA English DT Review DE Mars; Mars; surface; geological processes; mineralogy; atmospheres; evolution ID BANDED IRON-FORMATION; GOETHITE ALPHA-FEOOH; LEPIDOCROCITE GAMMA-FEOOH; WESTERN-AUSTRALIA; FERROUS IRON; KIRUNA TYPE; EARLY EARTH; MAGNETITE GEOCHEMISTRY; HYDROTHERMAL ORIGIN; HAMERSLEY PROVINCE AB The Thermal Emission Spectrometer (TES) on the Mars Global Surveyor spacecraft has detected deposits of coarse-grained, gray crystalline hematite in Sinus Meridiani, Aram Chaos, and Vallis Marineris. We argue that the key to the origin of gray hematite is that it requires crystallization at temperatures in excess of about 100 degreesC. We discuss thermal crystallization (1) as diagenesis at a depth of a few kilometers of sediments originally formed in low-temperature waters, or (2) as precipitation from hydrothermal solution. In Aram Chaos, a combination of TES data, Mars Orbiter Camera images, and Mars Orbiter Laser Altimeter (MOLA) topography suggests that high concentrations of hematite were formed in planar strata and have since been exposed by erosion of an overlying light-toned, caprock. Lesser concentrations of hematite are found adjacent to these strata at lower elevations, which we interpret as perhaps due to accumulation from physical weathering. The topography and the collapsed nature of the chaotic terrain favor a hydrothermally charged aquifer as the original setting where the hematite formed. Concentration of iron into such an ore-like body would be chemically favored by saline, Cl-rich hydrothermal fluids. An alternative sedimentary origin requires post-depositional burial to a depth of similar to 3-5 km to induce thermally driven recrystallization of fine-grained iron oxides to coarse-grained hematite. This depth of burial and re-exposure is difficult to reconcile with commonly inferred martian geological processes. However, shallow burial accompanied by post-burial hydrothermal activity remains plausible. When the hematite regions originally formed, redox balance requires that much hydrogen must have been evolved to complement the extensive oxidation. Finally, we suggest that the coexistence of several factors required to form the gray hematite deposits would have produced a favorable environment for primitive life on early Mars, if it ever existed. These factors include liquid water, abundant electron donors in the form of H-2, and abundant electron acceptors in the form of Fe3+. (C) 2003 Elsevier Inc. All rights reserved. C1 Univ Washington, Astrobiol Program, Seattle, WA 98195 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 93035 USA. RP Catling, DC (reprint author), Univ Washington, Astrobiol Program, Box 351640, Seattle, WA 98195 USA. RI Catling, David/D-2082-2009; OI Catling, David/0000-0001-5646-120X NR 154 TC 80 Z9 80 U1 3 U2 16 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD OCT PY 2003 VL 165 IS 2 BP 277 EP 300 DI 10.1016/S0019-1035(03)00173-8 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 729BZ UT WOS:000185752300004 ER PT J AU Johnson, NM Fegley, B AF Johnson, NM Fegley, B TI Longevity of fluorine-bearing tremolite on Venus SO ICARUS LA English DT Article DE Venus; Venus; surface; tremolite; fluorine; mineralogy ID IMPACT CRATERS; ATMOSPHERE; CLIMATE; WATER; DECOMPOSITION; SILICATES; EVOLUTION; HCL; HF AB There is a general belief that hydrous minerals cannot exist on Venus under current surface conditions. This view was challenged when Johnson and Fegley (2000, Icarus 146, 301-306) showed that tremolite (Ca2Mg5Si8O22(OH)(2)), a hydrous mineral, is stable against thermal decomposition at current Venus surface temperatures, e.g., 50% decomposition in 4 Ga at 740 K. To further explore hydrous mineral thermal stability on Venus, we experimentally determined the thermal decomposition kinetics of fluorine-bearing tremolite. Fluor-tremolite is thermodynamically more stable than OH-tremolite and should decompose more slowly. However how much slower was unknown. We measured the decomposition rate of fluorine-bearing tremolite and show that its decomposition is several times to greater than ten times slower than that of OH-tremolite. We also show that F-bearing tremolite is depleted in fluorine after decomposition and that fluorine is lost as a volatile species such as HF gas. If tremolite ever formed on Venus, it would probably also contain fluorine. The exceptional stability of F-bearing tremolite strengthens our conclusions that if hydrous minerals ever formed on Venus, they could still be there today. (C) 2003 Elsevier Inc. All rights reserved. C1 Washington Univ, Planetary Chem Lab, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Johnson, NM (reprint author), Washington Univ, Planetary Chem Lab, Dept Earth & Planetary Sci, Campus box 1169, St Louis, MO 63130 USA. RI Johnson, Natasha/E-3093-2012 NR 42 TC 6 Z9 6 U1 1 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD OCT PY 2003 VL 165 IS 2 BP 340 EP 348 DI 10.1016/S0019-1035(03)00212-4 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 729BZ UT WOS:000185752300008 ER PT J AU Gibb, EL Mumma, MJ Dello Russo, N DiSanti, MA Magee-Sauer, K AF Gibb, EL Mumma, MJ Dello Russo, N DiSanti, MA Magee-Sauer, K TI Methane in Oort cloud comets SO ICARUS LA English DT Article DE comets, composition; infrared observations; spectroscopy ID O1 HALE-BOPP; C/1996 B2 HYAKUTAKE; DEEPLY EMBEDDED PROTOSTARS; INFRARED-SPECTROSCOPY; PROTOPLANETARY DISKS; CARBON-MONOXIDE; SOLAR NEBULA; ETHANE; DUST; ACCRETION AB We detected CH4 in eight Oort cloud comets using high-dispersion (lambda/Deltalambdasimilar to2x10(4)) infrared spectra acquired with CSHELL at NASA's IRTF and NIRSPEC at the W.M. Keck Observatory. The observed comets were C/1995 O1 (Hale-Bopp), C/1996 B2 (Hyakutake), C/1 999 H1 (Lee), C/1999 T1 (McNaught-Hartley), C/1999 S4 (LINEAR), C/2000 WM1 (LINEAR), C/2001 A2 (LINEAR), and 153/P Ikeya-Zhang (C/2002 C1). We detected the R0 and R1 lines of the v(3) vibrational band of CH4 near 3.3 mum in each comet, with the exception of McNaught-Hartley where only the R0 line was measured. In order to obtain production rates, a fluorescence model has been developed for this band of CH4.We report g-factors for the R0 and R1 transitions at several rotational temperatures typically found in comet comae and relevant to our observations. Using g-factors appropriate to Trot as determined from HCN, CO and/or H2O and C2H6, CH4 production rates and mixing ratios are presented. Abundances of CH4/H2O are compared among our existing sample of comets, in the context of establishing their place of origin. In addition, CH4 is compared to native CO, another hypervolatile species, and no correlation is found among the comets observed. (C) 2003 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, NAS,NRC, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Rowan Univ, Dept Chem & Phys, Glassboro, NJ 08028 USA. RP Gibb, EL (reprint author), NASA, Goddard Space Flight Ctr, NAS,NRC, Extraterr Phys Lab, Code 690, Greenbelt, MD 20771 USA. 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 50 TC 73 Z9 73 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 0019-1035 J9 ICARUS JI Icarus PD OCT PY 2003 VL 165 IS 2 BP 391 EP 406 DI 10.1016/S0019-1035(03)00201-X PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 729BZ UT WOS:000185752300013 ER PT J AU Lorenz, RD McKay, CP AF Lorenz, RD McKay, CP TI A simple expression for vertical convective fluxes in planetary atmospheres SO ICARUS LA English DT Article DE atmospheres; dynamics; radiative transfer; prebiotic environments ID ENTROPY PRODUCTION; THERMAL STRUCTURE; CLIMATE; TITAN; GREENHOUSE; MODELS AB We explore the vertical convective flux F-c in a radiative-convective grey atmosphere. An expression of the form F-c= F(s)tau(o)/(C + Dtau(o)) appears useful, where F-s is the shortwave flux absorbed at the base of an atmosphere with longwave optical depth T, and C and D are constants. We find excellent agreement with an idealized grey radiative-convective model with no shortwave absorption for D = 1 and C = 1 similar to 2 depending on the surface-atmosphere temperature contrast and on the imposed critical lapse rate. Where shortwave absorption is correlated with longwave opacity, as in the atmospheres of Earth and Titan, C = 2, D = 2 provides an excellent fit, validated against the present terrestrial situation and the results of a nongrey model of Titan's strongly antigreenhouse atmosphere under a wide range of conditions. The expression may be useful for studying the energetics of planetary climates through time where there is insufficient data to constrain more elaborate models. (C) 2003 Elsevier Inc. All rights reserved. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Lorenz, RD (reprint author), Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. RI Lorenz, Ralph/B-8759-2016 OI Lorenz, Ralph/0000-0001-8528-4644 NR 20 TC 17 Z9 17 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD OCT PY 2003 VL 165 IS 2 BP 407 EP 413 DI 10.1016/S0019-1035(03)00205-7 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 729BZ UT WOS:000185752300014 ER PT J AU Ponchak, GE Tentzeris, EM Papapolymerou, J AF Ponchak, GE Tentzeris, EM Papapolymerou, J TI Coupling between microstrip lines embedded in polyimide layers for 3D-MMICs on Si SO IEE PROCEEDINGS-MICROWAVES ANTENNAS AND PROPAGATION LA English DT Article ID CROSSTALK; PACKAGES AB Three-dimensional circuits built on multiple layers of polyimide are required for constructing Si/SiGe monolithic microwave/millimetre-wave integrated circuits on CMOS (low resistivity) Si wafers. However, the closely spaced transmission lines are susceptible to high levels of coupling, which degrade circuit performance. In this paper, finite difference time domain (FDTD) analysis and measured characteristics of novel shielding structures that significantly reduce coupling between embedded microstrip lines are presented. A discussion of the electric and magnetic field distributions for the coupled microstrip lines is presented to provide a physical rationale for the presented results. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. RP Ponchak, GE (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 12 TC 2 Z9 2 U1 0 U2 0 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 1350-2417 J9 IEE P-MICROW ANTEN P JI IEE Proc.-Microw. Antennas Propag. PD OCT PY 2003 VL 150 IS 5 BP 344 EP 350 DI 10.1049/ip-map:20030545 PG 7 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 750CM UT WOS:000186973800007 ER PT J AU Simons, RN AF Simons, RN TI Novel on-wafer radiation-pattern measurement technique for MEMS actuator-based reconfigurable patch antennas SO IEEE ANTENNAS AND PROPAGATION MAGAZINE LA English DT Article DE antenna measurements; microelectromechanical devices; wafer scale integration; instrumentation; antenna radiation patterns; microstrip antennas; automated test equipment; reconfigurable architectures AB The paper presents a novel, on-wafer, antenna far-field pattern-measurement technique for micro-electromechanical systems(MEMS) based reconfigurable patch antennas. The measurement technique significantly reduces the time and the cost associated with the characterization of printed antennas fabricated on a semiconductor wafer or dielectric substrate. To measure the radiation patterns, the RF probe station is modified to accommodate an open-ended rectangular waveguide as the rotating linearly polarized sampling antenna. The open-ended waveguide is attached through a coaxial rotary joint to a Plexiglas((TM)) arm, and is driven along an arc by a stepper motor. Thus, the spinning open-ended waveguide can sample the relative field intensity of the patch as a function of the angle from boresight. The experimental results include the measured linearly polarized and circularly polarized radiation patterns for MEMS-based frequency-reconfigurable rectangular and polarization-reconfigurable nearly square patch antennas, respectively. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Simons, RN (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,Mail Stop 54-5, Cleveland, OH 44135 USA. NR 16 TC 0 Z9 0 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1045-9243 J9 IEEE ANTENNAS PROPAG JI IEEE Antennas Propag. Mag. PD OCT PY 2003 VL 45 IS 5 BP 163 EP 168 PG 6 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 747YQ UT WOS:000186834300015 ER PT J AU Deshpande, MD AF Deshpande, MD TI Comments on "Analysis of elliptical microstrip patch antenna considering attachment mode" SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Editorial Material C1 NASA Langley Res Ctr, Hampton, VA 23681 USA. RP Deshpande, MD (reprint author), NASA Langley Res Ctr, Hampton, VA 23681 USA. NR 2 TC 0 Z9 0 U1 0 U2 0 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 OCT PY 2003 VL 51 IS 10 BP 3018 EP 3018 DI 10.1109/TAP.2003.818368 PN 2 PG 1 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 731AE UT WOS:000185861700037 ER PT J AU Chevalier, CT Kory, CL Wilson, JD Wintucky, EG Dayton, JA AF Chevalier, CT Kory, CL Wilson, JD Wintucky, EG Dayton, JA TI Traveling-wave tube cold-test circuit optimization using CST MICROWAVE STUDIO SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article DE cold test; MICROWAVE STUDIO; optimization; slow-wave circuit; traveling-wave tube AB The internal optimizer of CST MICROWAVE STUDIO (MWS) was used along with an application-specific Visual Basic for Applications (VBA) script to develop a method to optimize traveling-wave tube (TWT) cold-test circuit performance. The optimization procedure allows simultaneous optimization of circuit specifications including on-axis interaction impedance, bandwidth or geometric limitations. The application of MWS to TWT cold-test circuit optimization is described below. C1 NASA, Glenn Res Ctr, Analex Corp, Cleveland, OH 44135 USA. RP Chevalier, CT (reprint author), NASA, Glenn Res Ctr, Analex Corp, Cleveland, OH 44135 USA. NR 7 TC 12 Z9 14 U1 0 U2 4 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 OCT PY 2003 VL 50 IS 10 BP 2179 EP 2180 DI 10.1109/TED.2003.816109 PG 2 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA 725WP UT WOS:000185565600025 ER PT J AU Chandrasekar, V Bolen, SM Gorgucci, E AF Chandrasekar, V Bolen, SM Gorgucci, E TI Microphysical cross validation of spaceborne radar and ground polarimetric radar SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT 22nd International Geoscience and Remote Sensing Symposium CY JUN 24-28, 2002 CL TORONTO, CANADA DE polarimetric radar; precipitation; space-based radar; Tropical Rainfall Measuring Mission (TRMM) ID TRMM PRECIPITATION RADAR; RAINDROP SIZE DISTRIBUTION; SHAPE; POLARIZATIONS; METHODOLOGY; CLOUD; DROPS AB Ground-based polarimetric radar observations along the beam path of the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR), matched in resolution volume and aligned to PR measurements, are used to estimate the parameters of a gamma raindrop size distribution (RSD) model along the radar beam in the presence of rain. The PR operates at 13.8 GHz, and its signal returns can undergo significant attenuation due to rain, which requires compensation to adequately assess the rain rate. The current PR algorithm used for attenuation correction of the reflectivity is cross-validated using ground-based dual-polarization radar measurements. Data from the Texas and Florida Underflights (TEFLUN-B) campaign and TRMM Large-scale Biosphere Atmosphere (LBA) experiment are used in the analysis. The statistical behavior of the raindrop size distribution parameters are presented along the vertical profile through the rain layer, which is used to evaluate the PR attenuation correction and rainfall algorithms. The PR rain rate estimates are compared to ground radar estimates. The standard error of the difference between the rainfall estimates from PR and ground radar was within the error of the rainfall estimates from the two instruments. Though no systematic differences between PR attenuation-corrected reflectivity and ground radar reflectivity measurements are observed, there may exist some undercorrection and overcorrection on a beam-by-beam basis. Comparison of the normalized reflectivity versus rainfall relation between PR and ground polarimetric radar is also presented. C1 Colorado State Univ, Ft Collins, CO 80523 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Roma Tor Vergata, Ist Fis Atmosfera, CNR, Area Ric, I-00133 Rome, Italy. RP Chandrasekar, V (reprint author), Colorado State Univ, Ft Collins, CO 80523 USA. NR 29 TC 11 Z9 11 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD OCT PY 2003 VL 41 IS 10 BP 2153 EP 2165 DI 10.1109/TGRS.2003.817186 PN 1 PG 13 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 733MG UT WOS:000186003900003 ER PT J AU Hornbuckle, BK England, AW De Roo, RD Fischman, MA Boprie, DL AF Hornbuckle, BK England, AW De Roo, RD Fischman, MA Boprie, DL TI Vegetation canopy anisotropy at 1.4 GHz SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT 22nd International Geoscience and Remote Sensing Symposium CY JUN 24-28, 2002 CL TORONTO, CANADA DE anisotropy; microwave radiometry; soil moisture; vegetation; volume scattering ID SURFACE SOIL-MOISTURE; PASSIVE MICROWAVE MEASUREMENTS; WATER-CONTENT; FIELD-MEASUREMENTS; UNITED-STATES; CROP FIELDS; EMISSION; MODEL; CORN; RADIOMETER AB We investigate anisotropy in 1.4-GHz brightness induced by a field corn vegetation canopy. We find that both polarizations of brightness are isotropic in azimuth during most of the growing season. When the canopy is senescent, the brightness is a strong function of row direction. On the other hand, the 1.4-GHz brightness is anisotropic in elevation: an isotropic zero-order radiative transfer model could not reproduce the observed change in brightness with incidence angle. Significant scatter darkening was found. The consequence of unanticipated scatter darkening would be a wet bias in soil moisture retrievals through a combination of underestimation of soil brightness (at H-pol) and underestimation of vegetation biomass (at V-pol). A new zero-order parameterization was formulated by allowing the volume scattering coefficient to be a function of incidence angle and polarization. The small magnitude of the scattering coefficients allows the zero-order model to retain its limited physical significance. C1 Iowa State Univ Sci & Technol, Dept Agron, Ames, IA 50011 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Elect Engn & Comp Sci, Ann Arbor, MI 48109 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Michigan, Space Phys Res Lab, Ann Arbor, MI 48109 USA. RP Hornbuckle, BK (reprint author), Iowa State Univ Sci & Technol, Dept Agron, Ames, IA 50011 USA. RI De Roo, Roger/J-2208-2012 OI De Roo, Roger/0000-0001-8391-2950 NR 45 TC 33 Z9 33 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD OCT PY 2003 VL 41 IS 10 BP 2211 EP 2223 DI 10.1109/TGRS.2003.817192 PN 1 PG 13 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 733MG UT WOS:000186003900008 ER PT J AU Chattopadhyay, G Glenn, J Bock, JJ Rownd, BK Caldwell, M Griffin, MJ AF Chattopadhyay, G Glenn, J Bock, JJ Rownd, BK Caldwell, M Griffin, MJ TI Feed horn coupled bolometer arrays for SPIRE - Design, simulations, and measurements SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE feed horn coupled arrays; Fourier transform spectrometer (FTS); HFSS simulations; integrating cavities; photometer; spider-web bolometers ID ORTHO-MODE TRANSDUCER AB In this paper, we present the design, modeling, and measurements of feed horn coupled large bolometer arrays being developed for the Herschel Space Observatory's Spectral and Photometric Imaging REceiver (SPIRE) instrument. SPIRE has five arrays of feed horn coupled silicon-nitride micromesh "spider-web" bolometers in two instruments, a three-band photometer, and a two-band Fourier transform spectrometer, each covering the 430-GHz-1.5-THz band. The optical coupling efficiency, bandwidth, and crosstalk between adjacent pixels of the arrays were investigated with numerical electromagnetic-field simulators, and prototype arrays were measured extensively in a test facility. The measured results were found to be in good agreement with simulation predictions, and the simulation results were-used as a benchmark for the design goals of the instrument. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80303 USA. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Cardiff Univ, Dept Phys & Astron, Cardiff CF10 3XQ, S Glam, Wales. RP Chattopadhyay, G (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91125 USA. NR 16 TC 23 Z9 23 U1 0 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD OCT PY 2003 VL 51 IS 10 BP 2139 EP 2146 DI 10.1109/TMTT.2003.817428 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA 728MA UT WOS:000185719900013 ER PT J AU Jun, I AF Jun, I TI Benchmark study for energy deposition by energetic electrons in thick elemental slabs: Monte Carlo results and experiments SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE energy deposition; ITS; MCNP4C ID DISTRIBUTIONS; TRANSPORT; ABSORBERS; BEAMS; CODES; EGS4; MCNP AB The energy deposition profiles when electrons with 0.5 MeV to 2 MeV kinetic energies impinge on a slab of elemental targets are presented in this paper. The target materials studied were single elements with atomic numbers between 6 and 73, thus covering representative low to high Z materials. The energy deposition profiles were computed using TIGER, the 1-D module of the Integrated Tiger Series (ITS) version 3.0, and MCNP4C. The targets were divided into the scoring subzones of 0.025r(o) thickness in all Monte Carlo simulations, where r(o) is the continuous slowing down approximation (CSDA) range of the incident electrons. Then, the computed profiles were compared to available experimental values. The comparison showed that the MCNP4C results followed the experimental data more closely than TIGER, especially in the broad peak regions. In general, however, the agreement of the energy deposition profiles computed by either code with the measured data was acceptable within the combined uncertainties of experiments and calculations. The observed discrepancies between the MCNP and TIGER results were due to different energy-indexing algorithms employed in the two codes. However, it was also found that the MCNP results were dependent on the user selection of the scoring subzone thickness, thus the MCNP simulations are subjected to some arbitrariness. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jun, I (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 24 TC 5 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD OCT PY 2003 VL 50 IS 5 BP 1732 EP 1739 DI 10.1109/TNS.2003.818270 PN 3 PG 8 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA 732CD UT WOS:000185922500004 ER PT J AU Choi, KK Lin, CH Leung, KM Tamir, T Mao, J Tsui, DC Jhabvala, M AF Choi, KK Lin, CH Leung, KM Tamir, T Mao, J Tsui, DC Jhabvala, M TI Broadband and narrow band light coupling for QWIPs SO INFRARED PHYSICS & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Workshop on Quantum Well Infrared Photodetectors (QWIP 2002) CY OCT 13-17, 2002 CL TURIN, ITALY DE infrared detector; quantum well; light-coupling; FPA ID WELL INFRARED PHOTODETECTORS; PERFORMANCE; WAVELENGTH AB In this work, we will present a detailed study on the corrugated coupling scheme, which uses optical reflection at the angled sidewalls. In particular, we have investigated, both theoretically and experimentally, corrugated quantum well infrared photodetectors (QWIPs) with different cover materials over a wide range of spectral regime. We found that the coupling is insensitive to the wavelength but depends strongly on the optical properties of the cover material. We will also present the results of C-QWIP focal plane arrays (FPA) characterized so far. An important advantage of the corrugated coupling is its scalability to small pixel size. Based on one corrugation per pixel geometry, we have fabricated a 1024 x 1024 C-QWIP FPA with 99.5% connectivity. With the corrugated coupling geometry, many application restrictions on QWIPs can be eliminated. We will further show that the lack of normal incident absorption in QWIPs can actually be an advantage. It allows one to manipulate the absorption characteristics of QWIPs through different optical coupling structures and creates new detector functionality. The present example is an infrared spectrometer. It consists of a linear array of quantum grid infrared photodetector (QGIP) elements. Each QGIP element shares the same QWIP material but has different grid geometry. The QWIP is made of broadband materials such as the binary superlattices to give an extremely broadband (similar to10 mum) absorption. The structure of the grid, on the other hand, determines the specific wavelength to detect at each detector element in the array. In the QGIP spectrometer, detectors with different line widths will detect different wavelengths simultaneously, thus yielding the emission spectrum of an object. A collection of QGIP spectrometers can form an adaptive FPA. (C) 2003 Elsevier B.V. All rights reserved. C1 USN, Res Lab, Electroopt & Photon Div, Adelphi, MD 20783 USA. Polytech Univ, Dept Elect & Comp Engn, Brooklyn, NY 11201 USA. Princeton Univ, Dept Elect Engn, Princeton, NJ 08544 USA. Goddard Space Flight Ctr, Instrument Technol Ctr, Greenbelt, MD 20771 USA. RP Choi, KK (reprint author), USN, Res Lab, Electroopt & Photon Div, 2800 Powder Mill Rd, Adelphi, MD 20783 USA. RI Choi, Kwong-Kit/K-9205-2013 NR 12 TC 12 Z9 13 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1350-4495 J9 INFRARED PHYS TECHN JI Infrared Phys. Technol. PD OCT-DEC PY 2003 VL 44 IS 5-6 BP 309 EP 324 DI 10.1016/S1350-4495(03)00150-6 PG 16 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 736GT UT WOS:000186163600002 ER PT J AU Bandara, SV Gunapala, SD Liu, JK Rafol, SB Ting, DZ Mumolo, JM Chuang, RW Trinh, TQ Liu, JH Choi, KK Jhabvala, M Fastenau, JM Liu, WK AF Bandara, SV Gunapala, SD Liu, JK Rafol, SB Ting, DZ Mumolo, JM Chuang, RW Trinh, TQ Liu, JH Choi, KK Jhabvala, M Fastenau, JM Liu, WK TI Four-band quantum well infrared photodetector array SO INFRARED PHYSICS & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Workshop on Quantum Well Infrared Photodetectors (QWIP 2002) CY OCT 13-17, 2002 CL TURIN, ITALY ID BROAD-BAND; WAVELENGTH; PERFORMANCE AB A four-band quantum well infrared photodetector (QWIP) focal plane array (FPA) has been demonstrated by stacking different multi-quantum well structures, which are sensitive in 4-5.5, 8.5-10, 10-12, and 13-15.5 mum infrared bands. This 640 x 514 format FPA consists of four 640 x 128 pixel areas which are capable of acquiring images in these infrared bands. In this application, instead of quarter wevelength groove depth grating reflectors, three-quarter wavelength groove depth reflectors were used to couple radiation to each QWIP layer. This technique allows us to optimize the light coupling to each QWIP stack at corresponding pixels while keeping the pixel (or mesa) height at the same level, which will be essential for indium bump-bonding with the multiplexer. In addition to light coupling, these gratings serve as a contact to the active stack while shorting the unwanted stacks. Flexible QWIP design parameters, such as well width, barrier thickness, doping density, and the number of periods, were cleverly exploited to optimize the performance of each detector while accommodating requirements set by the deep groove light coupling gratings. For imaging, detector array is operated at temperature T = 45 K, and each detector shows a very high D* > 1 x 10(11) cm rootHz/W for 300 K background with f/2 optics. This initial array gave excellent images with 99.9% of the pixels working, demonstrating the high yield of GaAs technology. (C) 2003 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. USA, Res Lab, Adelphi, MD 20783 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. IQE Inc, Bethlehem, PA 18015 USA. RP Bandara, SV (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Liu, Wing/B-7599-2009 NR 16 TC 22 Z9 28 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1350-4495 J9 INFRARED PHYS TECHN JI Infrared Phys. Technol. PD OCT-DEC PY 2003 VL 44 IS 5-6 BP 369 EP 375 DI 10.1016/S1350-4495(03)00157-9 PG 7 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 736GT UT WOS:000186163600009 ER PT J AU Gunapala, SD Bandara, SV Liu, JK Rafol, SB Mumolo, JM Shott, CA Jones, R Woolaway, J Fastenau, JM Liu, AK Jhabvala, M Choi, KK AF Gunapala, SD Bandara, SV Liu, JK Rafol, SB Mumolo, JM Shott, CA Jones, R Woolaway, J Fastenau, JM Liu, AK Jhabvala, M Choi, KK TI 640 x 512 pixel narrow-band, four-band, and broad-band quantum well infrared photodetector focal plane arrays SO INFRARED PHYSICS & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Workshop on Quantum Well Infrared Photodetectors (QWIP 2002) CY OCT 13-17, 2002 CL TURIN, ITALY DE focal plane arrays; QWIPs; hyper-spectral; multi-spectral; broad-band; multi-band; long-wavelength infrared (LWIR); hand-held infrared camera ID CAMERA AB A 9 mum cutoff 640x512 pixel hand-held quantum well infrared photodetector (QWIP) camera has been demonstrated with excellent imagery. A noise equivalent differential temperature (NEDT) of 10.6 mK is expected at a 65 K operating temperature with f/2 optics at a 300 K background. This focal plane array has shown background limited performance at a 72 K operating temperature with the same optics and background conditions. In this paper, we discuss the development of this very sensitive long-wavelength infrared camera based on a GaAs/AlGaAs QWIP focal plane array and its performance in quantum efficiency, NEDT, uniformity, and operability. In the second section of this paper, we discuss the first demonstration of a monolithic spatially separated four-band 640 x 512 pixel QWIP focal plane array and its performance. The four spectral bands cover 4-5.5, 8.5-10, 10-12, and 13.5-15 mum spectral regions with 640 x 128 pixels in each band. In the last section, we discuss the array performance of a 640 x 512 pixel broad-band (10-16 mum full-width at half-maximum) QWIP focal plane. (C) 2003 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Indigo Syst Corp, Santa Barbara, CA 93111 USA. IQE Inc, Bethlehem, PA 18015 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USA, Res Lab, Adelphi, MD 20783 USA. RP Gunapala, SD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 9 TC 24 Z9 27 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1350-4495 J9 INFRARED PHYS TECHN JI Infrared Phys. Technol. PD OCT-DEC PY 2003 VL 44 IS 5-6 BP 411 EP 425 DI 10.1016/S1350-4495(03)00162-2 PG 15 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 736GT UT WOS:000186163600014 ER PT J AU Jhabvala, M Gunapala, S Reuter, D Choi, KK Bandara, S Liu, J La, A Banks, S Cho, J Hwang, T Tsay, S Rafol, D Huet, H Chauvet, N Huss, T AF Jhabvala, M Gunapala, S Reuter, D Choi, KK Bandara, S Liu, J La, A Banks, S Cho, J Hwang, T Tsay, S Rafol, D Huet, H Chauvet, N Huss, T TI Development of a 4-15 mu m infrared GaAs hyperspectral QWIP imager SO INFRARED PHYSICS & TECHNOLOGY LA English DT Article; Proceedings Paper CT International Workshop on Quantum Well Infrared Photodetectors (QWIP 2002) CY OCT 13-17, 2002 CL TURIN, ITALY AB In the on-going evolution of GaAs quantum well infrared photodetectors (QWIPs) we have developed a four band, 640 x 512, 23 mum x 23 mum pixel array which we have subsequently integrated with a linear variable etalon (LVE) filter providing over 200 spectral bands across the 4-15.4 mum wavelength region. This effort was a collaboration between NASA's Goddard Space Flight Center (GSFC), the Jet Propulsion Laboratory (JPL) and the Army Research Laboratory (ARL) sponsored by the Earth Science Technology Office of NASA. The QWIP array was fabricated by graded molecular beam epitaxial (MBE) growth that was specifically tailored to yield four distinct bands (FWHM): Band 1; 4.5-5.7 mum, Band 2; 8.5-10 mum, Band 3; 10-12 mum and Band 4; 13.3-14.8 mum. Each band occupies a swath that comprises 128 x 640 elements. The addition of the LVE (which is placed directly over the array) further divides the four "broad" bands into 209 separate spectral bands ranging in width from 0.02 mum at 5 mum to 0.05 mum at 15 mum. The detector is cooled by a mechanical cryocooler to 46 K. The camera system is a fully reflective, f/4.2, 3-mirror system with a 21degrees x 25degrees field of view. The project goals were: (1) develop the 4 band GaAs QWIP array; (2) develop the LVE and; (3) implement a mechanical cryocooler. This paper will describe the efforts and results of this undertaking with emphasis on the overall system characteristics. (C) 2003 Elsevier B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. USA, Res Lab, Adelphi, MD 20783 USA. Sigma Space Corp, Lanham, MD 20706 USA. RP Jhabvala, M (reprint author), NASA, Goddard Space Flight Ctr, Bldg 11,Rm E30, Greenbelt, MD 20771 USA. RI Tsay, Si-Chee/J-1147-2014 NR 7 TC 4 Z9 5 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1350-4495 J9 INFRARED PHYS TECHN JI Infrared Phys. Technol. PD OCT-DEC PY 2003 VL 44 IS 5-6 BP 445 EP 455 DI 10.1016/S1350-4495(03)00172-5 PG 11 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 736GT UT WOS:000186163600017 ER PT J AU Qin, ZM Librescu, L Hasanyan, D Ambur, DR AF Qin, ZM Librescu, L Hasanyan, D Ambur, DR TI Magnetoelastic modeling of circular cylindrical shells immersed in a magnetic field. Part I: Magnetoelastic loads considering finite dimensional effects SO INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE LA English DT Article AB Determination of magnetoelastic loads acting on a perfectly electro-conductive circular cylindrical shell immersed in a uniform applied magnetic field is addressed. The finite dimensional effects related to the finite length and finite thickness of the shell are taken into consideration. Fourier integral method is used to derive the singular integral equations governing the distributed magnetoelastic loads. As special cases, determination of magnetoelastic loads via discarding the thickness effect are obtained from the general formulation, and the magnetoelastic loads of infinitely long shells are derived. Magnetoelastic loads on plate strips or infinite plates are also reduced from the general formulation. To the best of the authors' knowledge, this represents the first work devoted to the analytical determination of magnetoelastic loads on circular cylindrical shells considering the finite length and thickness effects. (C) 2003 Elsevier Ltd. All rights reserved. C1 Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. NASA, Langley Res Ctr, Mech & Durabil Branch, Hampton, VA 23681 USA. RP Librescu, L (reprint author), Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Mail Cose 0219, Blacksburg, VA 24061 USA. NR 10 TC 12 Z9 16 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7225 J9 INT J ENG SCI JI Int. J. Eng. Sci. PD OCT PY 2003 VL 41 IS 17 BP 2005 EP 2022 DI 10.1016/S0020-7225(03)00134-4 PG 18 WC Engineering, Multidisciplinary SC Engineering GA 708LF UT WOS:000184568000005 ER PT J AU Qin, ZM Hasanyan, D Librescu, L Ambur, DR AF Qin, ZM Hasanyan, D Librescu, L Ambur, DR TI Magnetoelastic modeling of circular cylindrical shells immersed in a magnetic field - Part II: Implications of finite dimensional effects on the free vibrations SO INTERNATIONAL JOURNAL OF ENGINEERING SCIENCE LA English DT Article AB In the context of free vibration analysis of axi-symmetric perfectly electro-conductive circular cylindrical shells, four simplified magnetoelastic load models are investigated. Concerning the model of circular cylindrical shells, a linear theory based on Love-Kirchhoff hypothesis is adopted. Due to the high complexities involving singularity of integral equations, infinite integral domains and excessive time needed to evaluate some kernels, special treatments are designed toward achieving highly efficient and highly accurate numerical computation. The influence of applied magnetic field, thickness ratio and dimensionless radius on free vibrations of circular cylindrical shells are further investigated and pertinent conclusions are outlined. (C) 2003 Elsevier Ltd. All rights reserved. C1 Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. NASA, Langley Res Ctr, Mech & Durabil Branch, Hampton, VA 23681 USA. RP Librescu, L (reprint author), Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Mail Cose 0219, Blacksburg, VA 24061 USA. NR 20 TC 6 Z9 6 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7225 J9 INT J ENG SCI JI Int. J. Eng. Sci. PD OCT PY 2003 VL 41 IS 17 BP 2023 EP 2046 DI 10.1016/S0020-7225(03)00135-6 PG 24 WC Engineering, Multidisciplinary SC Engineering GA 708LF UT WOS:000184568000006 ER PT J AU Kim, HJ Kihm, KD Allen, JS AF Kim, HJ Kihm, KD Allen, JS TI Examination of ratiometric laser induced fluorescence thermometry for microscale spatial measurement resolution SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID PARTICLE IMAGE VELOCIMETRY; TEMPERATURE-MEASUREMENTS; EMISSION; FIELDS AB Ratiometric laser induced fluorescence (LIF) thermometry technique has been quantitatively examined for its capability for a microscale field-of-view. The goal of the study is to quantitatively examine the measurement accuracy of the ratiometric LIF technique at sub-millimeter and micron scales for its potential use as a microscale temperature mapping tool. Measurements have been made for the steady temperature fields established by thermal buoyancy inside 1-mm wide closed test cell with low Grashof-Prandtl numbers (86 < Gr(w)Pr < 301), and the detailed measured data have been compared with the well-known predictions. The smallest measurement resolution could be achieved being equivalent to the CCD pixel size of 4.7 mum in the present experiment, but with large data uncertainties. The measurement uncertainties show persistent improvement to better than +/-1degreesC when measurement resolution is equivalent to 76 mum. (C) 2003 Elsevier Ltd. All rights reserved. C1 Texas A&M Univ, Dept Mech Engn, College Stn, TX 77843 USA. Ajou Univ, Div Mech & Ind Engn, Suwon 442749, South Korea. NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. RP Kihm, KD (reprint author), Texas A&M Univ, Dept Mech Engn, College Stn, TX 77843 USA. NR 25 TC 61 Z9 61 U1 1 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD OCT PY 2003 VL 46 IS 21 BP 3967 EP 3974 DI 10.1016/S0017-9310(03)00243-6 PG 8 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA 709CM UT WOS:000184607200002 ER PT J AU Barnes, RA Clark, DK Esaias, WE Fargion, GS Feldman, GC McClain, CR AF Barnes, RA Clark, DK Esaias, WE Fargion, GS Feldman, GC McClain, CR TI Development of a consistent multi-sensor global ocean colour time series SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article; Proceedings Paper CT International Workshop on Geospatial Knowledge Processing for Natural Resource Management CY JUN, 2001 CL VARESE, ITALY ID AEROSOL OPTICAL-PROPERTIES; SKY RADIANCE MEASUREMENTS; ATMOSPHERIC CORRECTION; TEMPERATURE SCANNER; CALIBRATION; SEAWIFS; CHLOROPHYLL; ABSORPTION; INVERSION; RETRIEVAL AB The advent of a new generation of space-borne ocean colour sensors brings the prospect of global ocean measurements for decades into the future. These measurements will provide the basis for characterizing variability in the structure of the ocean's phytoplanktonic communities and the response of those communities to climatic change. In addition, the measurements will allow development of the scientific basis necessary to manage the sustainable resources of marine ecosystems. These studies will require a merged, long-term, multi-satellite ocean colour time series extending beyond the operational lifetimes of individual instruments. The Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project has been tasked to develop the tools required to create this time series. Among these tools are a comprehensive in situ (field collected) bio-optical dataset for validating ocean optics algorithms and associated models of oceanic properties; a programme to evaluate different atmospheric correction techniques; a programme to link the calibrations of individual satellite instruments; a programme to develop consistent calibration and validation datasets for satellite instruments; and a set of alternate methods to combine ocean colour measurements from different sources into a single time series. We report on the progress of this development work by the SIMBIOS Project. C1 Sci Applicat Int Corp, Beltsville, MD 20705 USA. NASA, SIMBIOS Project, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, Natl Environm Satellite Data & Informat Serv, Camp Springs, MD USA. NASA, Oceans & Ice Branch, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, SeaWiFS Project, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Off Global Carbon Studies, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Barnes, RA (reprint author), Sci Applicat Int Corp, Beltsville, MD 20705 USA. NR 58 TC 18 Z9 19 U1 1 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 OCT PY 2003 VL 24 IS 20 BP 4047 EP 4064 DI 10.1080/0143116031000103862 PG 18 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 730HE UT WOS:000185823000012 ER PT J AU Nicholson, SE Some, B McCollum, J Nelkin, E Klotter, D Berte, Y Diallo, BM Gaye, I Kpabeba, G Ndiaye, O Noukpozounkou, JN Tanu, MM Thiam, A Toure, AA Traore, AK AF Nicholson, SE Some, B McCollum, J Nelkin, E Klotter, D Berte, Y Diallo, BM Gaye, I Kpabeba, G Ndiaye, O Noukpozounkou, JN Tanu, MM Thiam, A Toure, AA Traore, AK TI Validation of TRMM and other rainfall estimates with a high-density gauge dataset for West Africa. Part I: Validation of GPCC rainfall product and pre-TRMM satellite and blended products SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID PRECIPITATION CLIMATOLOGY PROJECT; GLOBAL PRECIPITATION; VARIABILITY AB Gauge data over North Africa are used to provide an assessment of satellite and blended rainfall products for 1988-94 and for 1998. A comparison is also made with the Global Precipitation Climatology Center (GPCC) gauge dataset. For the 1988-94 period, mean fields and latitudinal transects for the June-July-August season are presented, based on a 515-station gauge dataset, the GPCC gauge data, the Global Precipitation Climatology Project (GPCP) blended data, the infrared-based Geostationary Operational Environmental Satellite precipitation index (GPI), and the Special Sensor Microwave Imager (SSM/I) microwave estimates. Error calculations are also presented. The mean fields derived from the dense gauge network, the GPCC gauge-only analysis, and the GPCP are remarkably similar. The bias, with reference to the seasonal rainfall field based on the denser network, is about 3%-4% for either GPCC or GPCP. Agreement is relatively good, even in individual years. The rms error associated with these datasets is 12% for seasonal rainfall totals; thus, the error is largely random. In contrast, there are large systematic errors in the satellite-only analyses of GPI and SSM/I, with biases of 20% and 40% for the mean rain field as a whole and much larger biases in individual years. The rms errors are nearly 2 times as great. For 1998, a 920-station gauge dataset was available for a smaller section of West Africa. The comparison confirmed the superior performance of GPCP and demonstrated the lower level of performance of both GPCP and GPCC at the monthly scale as compared with the seasonal scale. Overall, the results of this study underscore the continued need for extensive gauge networks to describe adequately the large-scale precipitation field over Africa. C1 Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Serv Meteorol Natl, Ouagadougou, Burkina Faso. Ctr Reg AGRHYMET, Niamey, Niger. NOAA, NESDIS, ORA, Camp Springs, MD USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. SODEXAM, Direct Meteorol Natl, Abidjan, Cote Ivoire. Direct Natl Meteorol, Conakry, Guinea. Dept Water Resources, Banjul, Gambia. Direct Meteorol Natl, Lome, Togo. Direct Natl Meteorol, Dakar, Senegal. Direct Meteorol Natl, Cotonou, Benin. Meteorol Serv Dept, Legon, Ghana. Univ Arizona, Arizona Remote Sensing Ctr, Off Arid Lands Studies, Tucson, AZ USA. Direct Natl Meteorol, Bamako, Mali. Direct Meteorol Natl, Serv Climatol, Niamey, Niger. RP Nicholson, SE (reprint author), Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. NR 34 TC 85 Z9 87 U1 1 U2 14 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD OCT PY 2003 VL 42 IS 10 BP 1337 EP 1354 DI 10.1175/1520-0450(2003)042<1337:VOTAOR>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 727NP UT WOS:000185665200001 ER PT J AU Nicholson, SE Some, B McCollum, J Nelkin, E Klotter, D Berte, Y Diallo, BM Gaye, I Kpabeba, G Ndiaye, O Noukpozounkou, JN Tanu, MM Thiam, A Toure, AA Traore, AK AF Nicholson, SE Some, B McCollum, J Nelkin, E Klotter, D Berte, Y Diallo, BM Gaye, I Kpabeba, G Ndiaye, O Noukpozounkou, JN Tanu, MM Thiam, A Toure, AA Traore, AK TI Validation of TRMM and other rainfall estimates with a high-density gauge dataset for West Africa. Part II: Validation of TRMM rainfall products SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID GLOBAL PRECIPITATION; SATELLITE; INFORMATION; MICROWAVE; ORBIT AB Gauge data from a West African network of 920 stations are used to assess Tropical Rainfall Measuring Mission (TRMM) satellite and blended rainfall products for 1998. In this study, mean fields, scattergrams, and latitudinal transects for the months of May-September and for the 5-month season are presented. Error statistics are also calculated. This study demonstrates that both the TRMM-adjusted Geostationary Observational Environmental Satellite precipitation index (AGPI) and TRMM-merged rainfall products show excellent agreement with gauge data over West Africa on monthly-to-seasonal timescales and 2.5degrees x 2.5degrees latitude/longitude space scales. The root-mean-square error of both is on the order of 0.6 mm day(-1) at seasonal resolution and 1 mm day(-1) at monthly resolution. The bias of the AGPI is only 0.2 mm day(-1), whereas the TRMM-merged product shows no bias over West Africa. Performance at 1.0degrees x 1.0degrees latitude/longitude resolution is also excellent at the seasonal scale and good for the monthly scale. A comparison with standard rainfall products that predate TRMM shows that AGPI and the TRMM-merged product perform as well as, or better than, those products. The AGPI shows marked improvement when compared with the GPI, in reducing the bias and in the scatter of the estimates. The TRMM satellite-only products from the precipitation radar and the TRMM Microwave Imager do not perform well over West Africa. Both tend to overestimate gauge measurements. C1 Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Serv Meteorol Natl, Ouagadougou, Burkina Faso. Ctr Reg AGRHYMET, Niamey, Niger. NOAA, NESDIS, ORA, Camp Springs, MD USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Direct Meteorol Natl, SODEXAM, Abidjan, Cote Ivoire. Direct Natl Meteorol, Conakry, Guinea. Dept Water Resources, Banjul, Gambia. Direct Meteorol Natl, Lome, Togo. Direct Natl Meteorol, Dakar, Senegal. Direct Meteorol Natl, Cotonou, Benin. Meteorol Serv Dept, Legon, Ghana. Univ Arizona, Arizona Remote Sensing Ctr, Off Arid Lands Studies, Tucson, AZ USA. Direct Natl Meteorol, Bamako, Mali. Direct Meteorol Natl, Serv Climatol, Niamey, Niger. RP Nicholson, SE (reprint author), Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. NR 18 TC 135 Z9 139 U1 2 U2 20 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD OCT PY 2003 VL 42 IS 10 BP 1355 EP 1368 DI 10.1175/1520-0450(2003)042<1355:VOTAOR>2.0.CO;2 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 727NP UT WOS:000185665200002 ER PT J AU Heymsfield, AJ Matrosov, S Baum, B AF Heymsfield, AJ Matrosov, S Baum, B TI Ice water path-optical depth relationships for cirrus and deep stratiform ice cloud layers SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID CRYSTAL SIZE DISTRIBUTIONS; IN-SITU DATA; RADIATIVE PROPERTIES; MICROPHYSICAL PROPERTIES; RADAR MEASUREMENTS; TROPICAL CIRRUS; CLIMATE MODELS; DOPPLER RADAR; FIRE-II; PARAMETERIZATION AB Particle size distribution (PSD) and particle shape information collected during Lagrangian spiral descents and balloon ascents through 13 midlatitude and 6 tropical ice clouds are analyzed to investigate the relationship between cloud optical depth in visible wavelengths (tau(v)) and the ice water path (IWP). Although this sample size is small, it is far larger than the number of samples used in earlier studies and has the added benefit that it contains data from the top to the bottom of cloud layers, averaging 3 km in geometrical thickness. Furthermore, the observed particle shape and habit information are used directly in the investigation, rather than assuming that the habits are one of a number of pristine types. These observations apply to midlatitude clouds in the temperature range from -65degrees to -20degreesC, with tau(v) between 0.5 and 7, and estimated radar reflectivities primarily in the range from -20 to 5 dBZ(e) (at a frequency of 35 GHz), with some observations extending down to -45 dBZ(e). The tropical observations apply to clouds in the temperature range from -50degrees to -0degreesC, with tau(v) in the range 20-30, and radar reflectivities primarily between -5 and 25 dBZ(e) (at a frequency of 35 GHz). Quantitative relationships between tau(v) and IWP that depend on the cloud thickness, midcloud temperature, slope of the particle size distribution, median mass diameter, and effective radius are explored and developed. The underlying basis of these relationships is the correlation between the slope of the particle size distribution and cloud temperature or thickness. The slope of the particle size distribution tends to decrease with increasing cloud thickness ( beginning from cloud top) and temperature. This tendency toward a flatter spectral slope, with increasing penetration into the cloud layer, leads to a monotonic decrease in the extinction coefficient relative to the ice water content downward from the cloud top to base. Relationships between tau(v) and IWP as a function of the effective radius (r(e)) and the median mass diameter (D-m) are found from these observations, and are compared with those found in earlier studies. Given a value of the IWP and a known value of r(e), the earlier studies provide estimates of the tau(v) that are comparable to the results of this study. Several means of estimating r(e) and D-m indirectly, to circumvent the need to know the values of these variables directly from measurements, are developed. First, relationships are developed between r(e) and IWP. Second, relationships are developed to retrieve these variables from vertically pointing Doppler radar observations. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO USA. NOAA, Environm Technol Lab, Boulder, CO USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Heymsfield, AJ (reprint author), 3450 Mitchell Lane, Boulder, CO 80301 USA. RI Baum, Bryan/B-7670-2011; Heymsfield, Andrew/E-7340-2011 OI Baum, Bryan/0000-0002-7193-2767; NR 44 TC 57 Z9 57 U1 1 U2 6 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD OCT PY 2003 VL 42 IS 10 BP 1369 EP 1390 DI 10.1175/1520-0450(2003)042<1369:IWPDRF>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 727NP UT WOS:000185665200003 ER PT J AU Sohn, BJ Smith, EA AF Sohn, BJ Smith, EA TI Explaining sources of discrepancy in SSM/I water vapor algorithms SO JOURNAL OF CLIMATE LA English DT Article ID UPPER-TROPOSPHERIC HUMIDITY; SENSOR MICROWAVE IMAGER; GENERAL-CIRCULATION MODELS; CLOUD LIQUID WATER; GLOBAL OCEANS; PRECIPITABLE WATER; WIND-SPEED; BRIGHTNESS TEMPERATURES; SATELLITE-OBSERVATIONS; BOUNDARY-LAYER AB This study examines a mix of seven statistical and physical Special Sensor Microwave Imager (SSM/I) passive microwave algorithms that were designed for retrieval of over-ocean precipitable water (PW). The aim is to understand and explain why the algorithms exhibit a range of discrepancies with respect to measured PWs and with respect to each other, particularly systematic regional discrepancies that would produce substantive uncertainties in water vapor transports and radiative cooling in the context of climate dynamics. Data analysis is used to explore the nature of the algorithm differences, while radiative transfer analysis is used to explore the influence of several environmental variables (referred to as tangential environmental factors) that affect the PW retrievals. These are sea surface temperature (SST), surface wind speed (U-s), cloud liquid water path (LWP), and vertical profile structure of water vapor [q(z)]. The main datasets include the Wentz matched radiosonde SSM/I point database consisting of 42 months of globally distributed oceanic radiosonde profiles paired with coincident SSM/ I brightness temperatures, and globally compiled instantaneous orbit-swath maps of SSM/I brightness temperatures for January and July 1990. Results demonstrate that the seemingly good agreement found in past studies and herein, within the conventional framework of scatter diagram analysis that ignores regional classification, gives way to poor agreement in the framework of monthly and zonally averaged differences. It is shown how much of the disagreement inherent to statistical algorithms is due to disjoint training datasets used in deriving algorithm regression coefficients. The investigation also explores how tangential environmental factors composed of variations in SST, U-s, cloud LWP, and q(z) structure impart dissimilar errors to retrieved PWs, according to the design of the retrieval algorithms. A discussion on implications of the discrepancies vis-a-vis the Global Energy and Water Cycle Experiment program is given, with suggestions on mitigating discrepancies in algorithm designs. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Seoul Natl Univ, Sch Earth & Environm Sci, Seoul, South Korea. RP Smith, EA (reprint author), NASA, Goddard Space Flight Ctr, Code 912-1, Greenbelt, MD 20771 USA. NR 80 TC 23 Z9 24 U1 0 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 OCT PY 2003 VL 16 IS 20 BP 3229 EP 3255 DI 10.1175/1520-0442(2003)016<3229:ESODII>2.0.CO;2 PG 27 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 732LB UT WOS:000185945600001 ER PT J AU Chou, SH Nelkin, E Ardizzone, J Atlas, RM Shie, CL AF Chou, SH Nelkin, E Ardizzone, J Atlas, RM Shie, CL TI Surface turbulent heat and momentum fluxes over global oceans based on the Goddard Satellite retrievals, version 2 (GSSTF2) SO JOURNAL OF CLIMATE LA English DT Article ID SENSOR MICROWAVE IMAGER; AIR-SEA FLUXES; ATMOSPHERE RESPONSE EXPERIMENT; BULK AERODYNAMIC ALGORITHMS; WIND STRESS MEASUREMENTS; PACIFIC WARM POOL; TOGA COARE; EQUATORIAL PACIFIC; NCEP REANALYSES; BOUNDARY-LAYER AB Information on the turbulent fluxes of momentum, latent heat, and sensible heat at the air-sea interface is essential in improving model simulations of climate variations and in climate studies. A 13.5-yr (July 1987 December 2000) dataset of daily surface turbulent fluxes over global oceans has been derived from the Special Sensor Microwave Imager (SSM/I) radiance measurements. This dataset, Goddard Satellite-based Surface Turbulent Fluxes, version 2 (GSSTF2), has a spatial resolution of 1degrees X 1degrees latitude-longitude and a temporal resolution of 1 day. Turbulent fluxes are derived from the SSM/I surface winds and surface air humidity, as well as the 2-m air and sea surface temperatures (SST) of the NCEP-NCAR reanalysis, using a bulk aerodynamic algorithm based on the surface layer similarity theory. The GSSTF2 bulk flux model is validated by comparing hourly turbulent fluxes computed from ship data using the model with those observed fluxes of 10 field experiments over the tropical and midlatitude oceans during 1991-99. In addition, the GSSTF2 daily wind stress, latent heat flux, wind speed, surface air humidity, and SST compare reasonably well with those of the collocated measurements of the field experiments. The global distributions of 1988-2000 annual- and seasonal-mean turbulent fluxes show reasonable patterns related to the atmospheric general circulation and seasonal variations. Zonal averages of latent heat fluxes and input parameters over global oceans during 1992-93 have been compared among several flux datasets: GSSTF1 (version 1), GSSTF2, the Hamburg Ocean-Atmosphere Parameters and Fluxes from Satellite Data (HOAPS), NCEP-NCAR reanalysis, and one based on the Comprehensive Ocean-Atmosphere Data Set (COADS). Significant differences are found among the five. These analyses suggest that the GSSTF2 latent heat flux, surface air humidity, and winds are likely to be more realistic than the other four flux datasets examined, although those of GSSTF2 are still subject to regional biases. The GSSTF2 is useful for climate studies and has been submitted to the sea surface turbulent flux project (SEAFLUX) for intercomparison studies. C1 NASA, Atmospheres Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. Sci Applicat Int Corp, Laurel, MD USA. NASA, UMBC Goddard Earth & Sci Technol Ctr, Goddard Space Flight Ctr, Greenbelt, MD USA. RP Chou, SH (reprint author), NASA, Atmospheres Lab, Goddard Space Flight Ctr, Code 912, Greenbelt, MD 20771 USA. RI Atlas, Robert/A-5963-2011 OI Atlas, Robert/0000-0002-0706-3560 NR 47 TC 108 Z9 118 U1 3 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 OCT PY 2003 VL 16 IS 20 BP 3256 EP 3273 DI 10.1175/1520-0442(2003)016<3256:STHAMF>2.0.CO;2 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 732LB UT WOS:000185945600002 ER PT J AU Reeder, JR AF Reeder, JR TI Refinements to the mixed-mode bending test for delamination toughness SO JOURNAL OF COMPOSITES TECHNOLOGY & RESEARCH LA English DT Article DE delamination; composite; fracture toughness; mixed-mode; MMB; testing ID INTERLAMINAR FRACTURE; COMPOSITE-MATERIALS AB The mixed-mode bending (MMB) test for delamination toughness was first introduced in 1988. This simple test is a combination of the standard Mode I (opening) test and a Mode II (sliding) test. This MMB test has become widely used in the United States and around the world for mixed-mode toughness measurements. Because of the widespread use of this test method, it has been standardized by ASTM Committee D30 as ASTM Standard Test Method D6671. During the standardization process a round robin test activity was conducted that led to several modifications to the test protocol. These modifications included a new method for calculating toughness from the measured test quantities, a more accurate way of setting the mixed-mode ratio to be tested, and the inclusion of a new alignment criterion for improved consistency in measured values. The rational for these modifications, which were included in the test protocol before standardization, are discussed in this paper. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Reeder, JR (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 11 TC 22 Z9 22 U1 0 U2 3 PU AMER SOC TESTING MATERIALS PI W CONSHOHOCKEN PA 100 BARR HARBOR DR, W CONSHOHOCKEN, PA 19428-2959 USA SN 0884-6804 J9 J COMPOS TECH RES JI J. Compos. Technol. Res. PD OCT PY 2003 VL 25 IS 4 BP 191 EP 195 PG 5 WC Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA 751KA UT WOS:000187064600001 ER PT J AU Qiu, YM Uhl, D AF Qiu, YM Uhl, D TI Effect of thin GaAs interface layer on InAs quantum dots grown on InGaAs/InP using metalorganic vapor phase epitaxy SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE nanostructures; metalorganic vapor phase epitaxy; semiconductoring III-V materials ID DASH LASERS; WAVELENGTH; INP AB InAs self-assembled quantum dots (QDs) embedded within an InGaAs quantum well have been grown on InP substrate by low-pressure metalorganic vapor phase epitaxy. We find out that the underlying InGaAs layer could affect the dot growth dramatically in terms of size distribution and luminescence efficiency. After inserting a thin GaAs interface layer between the underlying InGaAs and the InAs QD layer, improved dot size uniformity and strong room temperature photoluminescence (PL) up to 2 mum were observed. In the case of InAs QDs with no GaAs layer, one has to reduce InAs QD layer thickness in order to obtain room temperature PL. These results suggest that InAs from the underlying InGaAs layer contribute to the InAs QD formation, and cause the InAs QDs to be non-uniform, but a thin GaAs interface layer could effectively block the migration of In atoms from the InGaAs layer toward InAs QDs, and therefore lead to more uniform QD formation with better luminescence efficiency. (C) 2003 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Qiu, YM (reprint author), CALTECH, Jet Prop Lab, MS 302-306,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 20 Z9 20 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 OCT PY 2003 VL 257 IS 3-4 BP 225 EP 230 DI 10.1016/S0022-0248(03)01456-8 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 722ZF UT WOS:000185407400002 ER PT J AU Yang, SL Siow, YK Teo, CY Tacina, RR Iannetti, AC Penko, PF AF Yang, SL Siow, YK Teo, CY Tacina, RR Iannetti, AC Penko, PF TI Numerical study of lean-direct injection combustor with discrete-jet swirlers using Reynolds stress model SO JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME LA English DT Article ID TURBULENCE AB The flowfield in a lean-direct injection (LDI) combustor with discrete-jet swirlers is described and analyzed using a computational fluid dynamics (CFD) code with a Reynolds stress turbulence model (RSTM). The results from the RSTM are compared to time-averaged laser-Doppler velocimetry (LDV) data, as well as results from the National Combustion Code (NCC) that has a cubic nonlinear kappa-epsilon turbulence model, and from the KIVA code using the standard kappa-epsilon model. The comparisons of results indicate that the RSTM accurately describes the flow details and resolves recirculation zones and high velocity gradients while the kappa-epsilon models are unable to capture most flow structures. This confirms that, within the Reynolds averaging approach, the higher-order RSTM is preferred for simulating complex flowfields where separations, strong anisotropy, and high swirl are present. C1 Michigan Technol Univ, Dept Mech Engn Engn Mech, Houghton, MI 49931 USA. NASA, Combust Technol Branch, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Yang, SL (reprint author), Michigan Technol Univ, Dept Mech Engn Engn Mech, Houghton, MI 49931 USA. NR 16 TC 2 Z9 4 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0742-4795 J9 J ENG GAS TURB POWER JI J. Eng. Gas. Turbines Power-Trans. ASME PD OCT PY 2003 VL 125 IS 4 BP 1059 EP 1065 DI 10.1115/1.1610012 PG 7 WC Engineering, Mechanical SC Engineering GA 753HR UT WOS:000187226400026 ER PT J AU Harik, VM AF Harik, VM TI Control of damage in composite laminates by ply-stacking designs: Characteristic failure signatures and safety criteria SO JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB Structural designs for composite laminated systems can be optimized for a fail-safe in-service performance by introducing the built-in cumulative-damage-indicators for the progressive degradation of material properties. This design methodology is based on the concepts of the characteristic failure signature (CFS), cumulative-damage states and a load-drop sequence that characterize the stress-strain response and progressive accumulation of damage. The cumulative damage mechanics is based on the three-dimensional laminate analysis that is used to predict nonlinear response of composites, accumulation of damage and failure behavior. An earlier-developed nonlinear analysis involves an incremental formulation that couples the three-dimensional laminate analysis with a progressive ply-failure methodology, which has been tested in the World-Wide Exercise on Composites Failure Theories. The failure signatures are shown to have unique "safety features" that depend on the ply stacking sequence and predominant loading. To refine the analysis of micromechanical damage a model for the macro-to-micro coupling is introduced. Various examples of failure envelopes, characteristic failure signatures, a safety criterion and the "safe" CFSs that lead to the desired controlled failures are discussed for symmetric balanced laminates. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Harik, VM (reprint author), Univ Delaware, Ctr Composite Mat, ARL Grp, Newark, DE 19716 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0094-4289 J9 J ENG MATER-T ASME JI J. Eng. Mater. Technol.-Trans. ASME PD OCT PY 2003 VL 125 IS 4 BP 385 EP 393 DI 10.1115/1.1605771 PG 9 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 732FF UT WOS:000185929600008 ER PT J AU Wu, SC Remington, RW AF Wu, SC Remington, RW TI Characteristics of covert and overt visual orienting: Evidence from attentional and oculomotor capture SO JOURNAL OF EXPERIMENTAL PSYCHOLOGY-HUMAN PERCEPTION AND PERFORMANCE LA English DT Article; Proceedings Paper CT 42nd Annual Meeting of the Psychonomic-Society CY NOV 15-19, 2001 CL ORLANDO, FLORIDA SP Psychon Soc ID SACCADE TARGET SELECTION; LATERAL INTRAPARIETAL AREA; OVERLAPPING NEURAL SYSTEMS; POSTERIOR PARIETAL CORTEX; FRONTAL EYE FIELD; SUPERIOR COLLICULUS; CONTROL SETTINGS; CEREBRAL-CORTEX; ABRUPT ONSETS; MOVEMENTS AB Five visual search experiments found oculomotor and attentional capture consistent with predictions of contingent orienting, contrary to claims that oculomotor. capture is purely stimulus driven. Separate saccade and attend-only conditions contained a color target appearing either singly, with an onset or color distractor, or both. In singleton mode, onsets produced oculomotor and attentional capture. In feature mode,:capture was absent or greatly reduced, providing evidence for top-down modulation of both types of capture. Although attentional capture by color distractors was present throughout, oculomotor capture by color occurred only when accompanied by transient change, providing evidence for a dissociation between oculomotor and attentional capture. Oculomotor and attentional capture appear to be mediated by top-down attentional control settings, but transient change may be necessary for oculomotor capture. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Wu, SC (reprint author), NASA, Ames Res Ctr, Mail Stop 262-4, Moffett Field, CA 94035 USA. NR 62 TC 47 Z9 48 U1 0 U2 2 PU AMER PSYCHOLOGICAL ASSOC PI WASHINGTON PA 750 FIRST ST NE, WASHINGTON, DC 20002-4242 USA SN 0096-1523 J9 J EXP PSYCHOL HUMAN JI J. Exp. Psychol.-Hum. Percept. Perform. PD OCT PY 2003 VL 29 IS 5 BP 1050 EP 1067 DI 10.1037/0096-1523.29.5.1050 PG 18 WC Psychology; Psychology, Experimental SC Psychology GA 737ZB UT WOS:000186261300015 PM 14585022 ER PT J AU Molod, A Salmun, H Waugh, DW AF Molod, A Salmun, H Waugh, DW TI A new look at modeling surface heterogeneity: Extending its influence in the vertical SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID GENERAL-CIRCULATION MODELS; BOUNDARY-LAYER; NUMERICAL-MODELS; SCALE; PARAMETERIZATION; CLIMATOLOGY; FLUXES; PRECIPITATION; IMPACT; SIB AB Heterogeneities in the land surface exist on a wide range of spatial scales and make the coupling between the land surface and the overlying boundary layer complex. This study investigates the vertical extent to which the surface heterogeneities affect the boundary layer turbulence. A technique called "extended mosaic'' is presented. It models the coupling between the heterogeneous land surface and the atmosphere by allowing the impact of the subgrid-scale variability to extend throughout the vertical extent of the planetary boundary layer. Simulations with extended mosaic show that there is a GCM level at which the distinct character of the turbulence over different land scene types is homogenized, which the authors call the model blending height. The behavior of the model blending height is an indicator of the mechanism by which the surface heterogeneities extend their direct influence upward into the boundary layer and exert their influence on the climate system. Results are presented that show the behavior of the model blending height and the relationships to atmospheric and surface conditions. The model blending height is generally one-third to one-half of the planetary boundary layer height, although the exact ratio varies with local conditions and the distribution of the underlying vegetation. The model blending height also increases with canopy temperature and sensible heat flux and is influenced by the amount of variability in the surface vegetation and the presence of deciduous trees. C1 Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 20218 USA. CUNY Hunter Coll, Dept Geog, New York, NY 10021 USA. NASA, Goddard Space Flight Ctr, Data Assimilat Off, Greenbelt, MD 20771 USA. RP Molod, A (reprint author), Johns Hopkins Univ, Dept Earth & Planetary Sci, 3400 N Charles St, Baltimore, MD 20218 USA. RI Waugh, Darryn/K-3688-2016 OI Waugh, Darryn/0000-0001-7692-2798 NR 34 TC 19 Z9 20 U1 0 U2 8 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 1525-755X J9 J HYDROMETEOROL JI J. Hydrometeorol. PD OCT PY 2003 VL 4 IS 5 BP 810 EP 825 DI 10.1175/1525-7541(2003)004<0810:ANLAMS>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 732KX UT WOS:000185945200004 ER PT J AU Provenzano, V Li, J King, T Canavan, E Shirron, P DiPirro, M Shull, RD AF Provenzano, V Li, J King, T Canavan, E Shirron, P DiPirro, M Shull, RD TI Enhanced magnetocaloric effects in R-3(Ga1-xFex)(5)O-12 (R = Gd, Dy, Ho; 0 < x < 1) nanocomposites SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article; Proceedings Paper CT 4th International Conference on Fine Particle Magnetism (ICFPM) CY AUG 14-16, 2002 CL PITTSBURGH, PENNSYLVANIA DE magnetocaloric effect; magnetic cooling; nanocomposite garnets; paramagnetic; superparamagnetic AB A series of R-3(Ga1-xFex)(5)O-12 (R=Gd, Dy, Ho; 0 1 Hz) sulfur dioxide (SO2) measurements were obtained using an atmospheric pressure ionization mass spectrometer with isotopically labeled internal standard on the NASA Wallops P-3B during the NASA Transport and Chemical Evolution Over the Pacific ( TRACE-P) field experiment. The high time resolution for SO2 allowed a view into the dynamics of SO2 transport, including the effects of clouds. Two missions along 124.5degreesE from the vicinity of Taiwan to the northern Yellow Sea near the Korean peninsula were flown on consecutive days with quite different weather conditions. Although the winds on both flights were westerly to northwesterly, the SO2 concentrations were markedly different in vertical and horizontal distributions. Together with turbulence measurements and other high rate data on the P-3B, we have assessed how cloud processing and atmospheric dynamics may have caused the differences in the SO2 distributions. Below 2 km, SO2 layers of a few hundred meters depth were often isolated from the mixed layer. The relatively slow process of entrainment limited loss of SO2 to the marine mixed layer. When compared to 3-D model results of SO2 along the flight track, the in situ SO2 data showed that the model poorly represented the SO2 distribution along the flight track for the cloudy day, while the model gave a reasonably good representation of the in situ data during the clear air flight. On the clear air flight day, the model achieved a closer representation of the SO2 distribution, but it overestimated the SO2 concentrations just above the well-mixed boundary layer. The deviations between the observations and the model appear to be related the treatment of the boundary layer dynamics. C1 Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA. Univ Iowa, Ctr Global & Reg Environm Res, Iowa City, IA 52242 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA. EM fhtu@drexel.edu; thorntdc@drexel.edu; alan.bandy@drexel.edu; gcarmich@engineering.uiowa.edu; ytang@cgrer.uiowa.edu; k.l.thornhill@larc.nasa.gov RI Tang, Youhua/D-5205-2016 OI Tang, Youhua/0000-0001-7089-7915 NR 31 TC 16 Z9 16 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 18 PY 2003 VL 108 IS D20 AR 8790 DI 10.1029/2002JD003227 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 724FM UT WOS:000185477600002 ER PT J AU Gaucher, EA Thomson, JM Burgan, MF Benner, SA AF Gaucher, EA Thomson, JM Burgan, MF Benner, SA TI Inferring the palaeoenvironment of ancient bacteria on the basis of resurrected proteins SO NATURE LA English DT Article ID ELONGATION-FACTOR TU; COMMON ANCESTOR; EVOLUTION; THERMOSTABILITY; RIBONUCLEASE; DIVERSITY; SEQUENCES; LIFE AB Features of the physical environment surrounding an ancestral organism can be inferred by reconstructing sequences(1-9) of ancient proteins made by those organisms, resurrecting these proteins in the laboratory, and measuring their properties. Here, we resurrect candidate sequences for elongation factors of the Tu family (EF-Tu) found at ancient nodes in the bacterial evolutionary tree, and measure their activities as a function of temperature. The ancient EF-Tu proteins have temperature optima of 55-65degreesC. This value seems to be robust with respect to uncertainties in the ancestral reconstruction. This suggests that the ancient bacteria that hosted these particular genes were thermophiles, and neither hyperthermophiles nor mesophiles. This conclusion can be compared and contrasted with inferences drawn from an analysis of the lengths of branches in trees joining proteins from contemporary bacteria(10), the distribution of thermophily in derived bacterial lineages(11), the inferred G+C content of ancient ribosomal RNA(12), and the geological record combined with assumptions concerning molecular clocks(13). The study illustrates the use of experimental palaeobiochemistry and assumptions about deep phylogenetic relationships between bacteria to explore the character of ancient life. C1 Univ Florida, NASA, Astrobiol Inst, Gainesville, FL 32611 USA. Univ Florida, Coll Med, Dept Anat & Cell Biol, Gainesville, FL 32611 USA. Univ Florida, Dept Chem, Gainesville, FL 32611 USA. RP Gaucher, EA (reprint author), Univ Florida, NASA, Astrobiol Inst, Gainesville, FL 32611 USA. RI Gaucher, Eric/I-7313-2013 NR 30 TC 128 Z9 133 U1 2 U2 33 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 18 PY 2003 VL 425 IS 6955 BP 285 EP 288 DI 10.1038/nature01977 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 722JA UT WOS:000185370900042 PM 13679914 ER PT J AU Bramstedt, K Gleason, J Loyola, D Thomas, W Bracher, A Weber, M Burrows, JP AF Bramstedt, K Gleason, J Loyola, D Thomas, W Bracher, A Weber, M Burrows, JP TI Comparison of total ozone from the satellite instruments GOME and TOMS with measurements from the Dobson network 1996-2000 SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID RADIATIVE-TRANSFER MODEL; RETRIEVAL; ACCURACY AB Over the last 3 decades, satellite data have been used to monitor long-term global changes in stratospheric ozone. The TOMS series (1978-present) and GOME (1995-present) are two very important instruments in this context. In this paper, TOMS total ozone and three approaches to derive total ozone from GOME measurements are validated with ground-based Dobson network data. Beyond the operational products of both instruments, e. g. TOMS version 7 and GOME Data Processor version 2.7, total ozone is calculated by integrating FURM ozone profiles and by applying the TOMS algorithm to the GOME spectra. All algorithms show in general good agreement with ground-based measurements. The operational GOME total ozone shows seasonal variations, most likely introduced by difficulties in the derivation of airmass factors, which convert measured slant columns into vertical columns. The TOMS algorithm estimates on average 2% higher total ozone in the southern hemisphere than in the northern for both instruments as compared to the ground-based data, indicating that the source of the observed hemispheric differences is in the TOMS algorithm. Both instruments show aging effects in 2000, leading to enhanced variability in the ozone column differences with respect to Dobson data. In addition, the integrated GOME ozone profiles and the TOMS algorithm applied to GOME data show larger mean deviations in 2000. C1 Univ Bremen, Inst Environm Phys, Bremen, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. DLR, Remote Sensing Technol Inst, IMF, Wessling, Germany. RP Bramstedt, K (reprint author), Univ Bremen, Inst Environm Phys, Bremen, Germany. RI Weber, Mark/F-1409-2011; Gleason, James/E-1421-2012; Bracher, Astrid/B-7805-2013; OI Weber, Mark/0000-0001-8217-5450; Bracher, Astrid/0000-0003-3025-5517; Loyola R., Diego G./0000-0002-8547-9350; Burrows, John Philip/0000-0002-6821-5580 NR 38 TC 34 Z9 36 U1 0 U2 0 PU EUROPEAN GEOPHYSICAL SOC PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD SEP 17 PY 2003 VL 3 BP 1409 EP 1419 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 726VP UT WOS:000185622100001 ER PT J AU Hou, TH Costen, RC AF Hou, TH Costen, RC TI Behavior of volatile depletion for LaRc (TM)-PETI-5 amide acid/N-methylpyrrolidinone solution SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article DE polyimide; polyimide composite; votalile management; LaRC (TM)-PETI-5 ID DIELECTRIC ANALYSIS; COMPOSITES; CURE AB The fabrication of composites from polyimide precursors (polyamide acids) that involve condensation reactions requires the removal of volatiles (solvent and reaction by-products) prior to consolidation in order to achieve a void-free laminate. Volatile removal is commonly accomplished with a B-stage processing step. In this study, a PETAA/NMP (phenylethynyl terminated amide acid in N-methylpyrrolidinone) solution and prepreg were characterized using therogravimetric analysis (TGA) and microdielectrometry. A master weight loss profile was constructed by superimposing measurements at various heating rates. The TGA results correlated well with the dielectric ionic conductivities. Under the same thermal conditions, volatiles were depleted at slower rates from the wet prepreg than the neat resin solution. Dielectric properties were more sensitive to the residual volatile contents than the TGA measurements in both the neat resin and wet prepreg. Dielectric sensing technology was demonstrated to be a feasible tool for future volatile management in the fabrication of PETI composites. This study demonstrates that the combination of TGA and dielectrometry provides useful information to develop proper processing conditions for composite fabrication from prepregs containing volatiles. (C) 2003 Wiley Periodicals, Inc. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Hou, TH (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 13 TC 2 Z9 2 U1 0 U2 1 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD SEP 17 PY 2003 VL 90 IS 7 BP 1906 EP 1916 DI 10.1002/app.12865 PG 11 WC Polymer Science SC Polymer Science GA 726PF UT WOS:000185607500025 ER PT J AU Yang, P Mlynczak, MG Wei, H Kratz, DP Baum, BA Hu, YX Wiscombe, WJ Heidinger, A Mishchenko, MI AF Yang, P Mlynczak, MG Wei, H Kratz, DP Baum, BA Hu, YX Wiscombe, WJ Heidinger, A Mishchenko, MI TI Spectral signature of ice clouds in the far-infrared region: Single-scattering calculations and radiative sensitivity study SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE far-infrared; cirrus cloud; ice crystal ID DIFFERENCE TIME-DOMAIN; CIRRUS CLOUDS; LIGHT-SCATTERING; MU-M; ACCURATE PARAMETERIZATION; EXTINCTION EFFICIENCY; OPTICAL-PROPERTIES; CLIMATE MODELS; T-MATRIX; ABSORPTION AB [1] We investigate the spectral signature of ice clouds in the far-infrared (far-IR) spectral region from 100 to 667 cm(-1) (15 - 100 mum). Individual particle scattering properties ( extinction efficiency, absorption efficiency, and the asymmetry factor of the scattering phase function) are calculated for small particles using circular cylinders and for large crystals using hexagonal columns. The scattering properties are computed for particle sizes over a size range from 1 to 10,000 mm in maximum dimension from a combination of the T-matrix method, the Lorenz-Mie theory, and an improved geometric optics method. Bulk scattering properties are derived subsequently for 30 particle size distributions, with effective particle sizes ranging from 15 to 150 mm, obtained from various field campaigns for midlatitude and tropical cirrus clouds. Furthermore, a parameterization of the bulk scattering properties is developed. The radiative properties of ice clouds and the clear-sky optical thickness computed from the line-by-line method are input to a radiative transfer model to simulate the upwelling spectral radiance in the far-IR spectral region at the research aircraft height ( 20 km). On the basis of the simulations, we investigate the sensitivity of far-IR spectra to ice cloud optical thickness and effective particle size. The brightness temperature difference (BTD) between 250 and 559.5 cm(-1) is shown to be sensitive to optical thickness for optically thin clouds ( visible optical thickness tau < 2). At the other extreme, for optically thick ice clouds (tau > 8), the BTD between 250 and 410.2 cm(-1) is shown to be sensitive to the effective particle size up to a limit of 100 mum. C1 Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Madison, WI 53706 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Texas A&M Univ, Dept Atmospher Sci, TAMU 3150, College Stn, TX 77843 USA. EM pyang@ariel.met.tamu.edu RI Heidinger, Andrew/F-5591-2010; Yang, Ping/B-4590-2011; Baum, Bryan/B-7670-2011; Mlynczak, Martin/K-3396-2012; Wiscombe, Warren/D-4665-2012; Hu, Yongxiang/K-4426-2012; Mishchenko, Michael/D-4426-2012 OI Heidinger, Andrew/0000-0001-7631-109X; Baum, Bryan/0000-0002-7193-2767; Wiscombe, Warren/0000-0001-6844-9849; NR 49 TC 28 Z9 28 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 17 PY 2003 VL 108 IS D18 AR 4569 DI 10.1029/2002JD003291 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 754HV UT WOS:000187310800003 ER PT J AU Yang, RQ Hill, CJ Yang, BH Liu, JK AF Yang, RQ Hill, CJ Yang, BH Liu, JK TI Room-temperature type-II interband cascade lasers near 4.1 mu m SO APPLIED PHYSICS LETTERS LA English DT Article AB Operation of type-II interband cascade lasers has been demonstrated in pulsed mode at room temperatures at wavelengths near 4.1 mum. These lasers fabricated with 150 mum wide mesa stripes also operated in cw mode at temperatures up to 145 K. Threshold current densities as low as 9 A/cm(2) and output powers exceeding 100 mW/f have been achieved in cw mode at 80 K. (C) 2003 American Institute of Physics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Yang, RQ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 27 Z9 28 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 SEP 15 PY 2003 VL 83 IS 11 BP 2109 EP 2111 DI 10.1063/1.1611260 PG 3 WC Physics, Applied SC Physics GA 719XU UT WOS:000185231000007 ER PT J AU Cruden, BA Cassell, AM Ye, Q Meyyappan, M AF Cruden, BA Cassell, AM Ye, Q Meyyappan, M TI Reactor design considerations in the hot filament/direct current plasma synthesis of carbon nanofibers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; FIELD-EMISSION; DC PLASMA; NANOTUBES; GROWTH; ARRAYS; ALIGNMENT; DIAMOND AB A combined hot filament/direct current (dc) plasma approach to chemical vapor deposition of carbon nanofibers (CNFs) using an acetylene/ammonia feedstock has been explored. As a part of the study, the impact of filament usage and substrate holder design has been examined by scanning electron microscopy imaging of deposition products and monitoring of downstream products by residual gas analysis (RGA). It is demonstrated that the filament wire is important primarily in the pretreatment of the substrate, improving CNF growth quality. However, the filament has a more minor impact when combined with the dc plasma, increasing growth rate but reducing growth quality. The substrate holder is modified by introducing a graphite spacer into the electrode. By varying the size of the spacer, the effective surface area of the cathode is modified, allowing control over the power input to the reactor while holding the voltage constant. This allows for some independent control of physicochemical processes that are typically inseparable in plasma processing, including gas phase chemistry, substrate heating and etching by ion bombardment, and growth alignment effects due to the electric field. This work demonstrates how separating these processes allows for better control over the desired growth product. (C) 2003 American Institute of Physics. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. Eloret Corp, Sunnyvale, CA 94087 USA. RP Cruden, BA (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. NR 26 TC 93 Z9 96 U1 2 U2 18 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 2003 VL 94 IS 6 BP 4070 EP 4078 DI 10.1063/1.1601293 PG 9 WC Physics, Applied SC Physics GA 723EN UT WOS:000185419600059 ER PT J AU Sun, S Hansen, JE AF Sun, S Hansen, JE TI Climate simulations for 1951-2050 with a coupled atmosphere-ocean model SO JOURNAL OF CLIMATE LA English DT Article ID SURFACE AIR-TEMPERATURE; THERMOHALINE CIRCULATION; NORTH-ATLANTIC; GODDARD-INSTITUTE; UNITED-STATES; WORLD OCEAN; HEAT UPTAKE; CO2; GCM; PARAMETERIZATION AB The authors simulate climate change for 1951 - 2050 using the GISS SI2000 atmospheric model coupled to HYCOM, a quasi-isopycnal ocean model ("ocean E''), and contrast the results with those obtained using the same atmosphere coupled to a passive Q-flux ocean model ("ocean B'') and the same atmosphere driven by observed SST ("ocean A''). All of the models give reasonable agreement with observed global temperature change during 1951 - 2000, but the quasi-isopycnal ocean E mixes heat more deeply and hence sequesters heat more effectively on the century timescale. Global surface warming in the next 50 yr is only 0.3degrees - 0.4degreesC with this ocean in simulations driven by an "alternative scenario'' climate forcing (1.1 W m(-2) in the next 50 yr), only half as much as with ocean B. From the different models the authors estimate that the earth was out of radiation balance by about 0.18 W m(-2) in 1951 and is now out of balance by about 0.75 W m(-2). This energy imbalance, or residual climate forcing, a consequence of deep ocean mixing of heat anomalies and the history of climate forcings, is a crucial measure of the state of the climate system that should be precisely monitored with full-ocean temperature measurements. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Sun, S (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM ssun@giss.nasa.gov RI Sun, Shan/H-2318-2015 NR 63 TC 33 Z9 34 U1 1 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP 15 PY 2003 VL 16 IS 17 BP 2807 EP 2826 DI 10.1175/1520-0442(2003)016<2807:CSFWAC>2.0.CO;2 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 715KA UT WOS:000184969600003 ER PT J AU Raj, SV AF Raj, SV TI Tensile creep of polycrystalline near-stoichiometric NiAl SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE NiAl; tensile creep; high temperature deformation; activation energy; primary creep ID SOLID-SOLUTION ALLOYS; THERMALLY ACTIVATED DEFORMATION; PLASTIC-FLOW PROPERTIES; STEADY-STATE CREEP; SINGLE-CRYSTALS; DEGREES C; ATOMISTIC SIMULATION; VISCOUS GLIDE; POINT-DEFECTS; GRAIN-SIZE AB Long term tensile creep studies were conducted on binary NiAl in the temperature range 700-1200 K with the objectives of characterizing and understanding the creep mechanisms. Inverse and normal primary creep curves were observed depending on stress and temperature. It is concluded that the primary creep of NiAl is limited by dislocation mobility. The stress exponent for creep, n, decreased from 13.9 at 700 K to 5.5 at 1200 K. The true activation energy for creep, Q(c), was constant and equal to about 400 kJ mol(-1) between 20 and 50 MPa but decreased to a constant value of 250 kJ mol(-1) between 50 and 110 MPa. The activation energy was observed to be stress dependent above 110 MPa. The tensile creep results reported in this investigation were compared with compression creep data reported in the literature. A detailed discussion of the probable dislocation creep mechanisms governing compressive and tensile creep of NiAl is presented. It is concluded that the non-conservative motion of jogs on screw dislocations influenced the nature of the primary creep curves, where the climb of these jogs involves either the next nearest neighbor or the six-jump cycle vacancy diffusion mechanism. A phenomenological model discusses the nature of the atom-vacancy exchange process likely to lead to the climb of these jogs. (C) 2003 Elsevier Science B.V. All rights reserved. C1 NASA, Glenn Res Ctr, Div Mat, Cleveland, OH 44135 USA. RP Raj, SV (reprint author), NASA, Glenn Res Ctr, Div Mat, MS 106-5,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 57 TC 9 Z9 9 U1 1 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 15 PY 2003 VL 356 IS 1-2 BP 283 EP 297 DI 10.1016/S0921-5093(03)00137-0 PG 15 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 705MN UT WOS:000184399000034 ER PT J AU Mingo, N AF Mingo, N TI Calculation of Si nanowire thermal conductivity using complete phonon dispersion relations SO PHYSICAL REVIEW B LA English DT Article ID LOW-TEMPERATURES; CRYSTALS; WIRES AB The lattice thermal conductivity of crystalline Si nanowires is calculated. The calculation uses complete phonon dispersions, and does not require any externally imposed frequency cutoffs. No adjustment to nanowire thermal conductivity measurements is required. Good agreement with experimental results for nanowires wider than 35 nm is obtained. A formulation in terms of the transmission function is given. Also, the use of a simpler, nondispersive "Callaway formula," is discussed from the complete dispersions perspective. C1 NASA, Ames Res Ctr, Eloret Corp, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, Eloret Corp, Moffett Field, CA 94035 USA. NR 19 TC 281 Z9 281 U1 5 U2 63 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2003 VL 68 IS 11 AR 113308 DI 10.1103/PhysRevB.68.113308 PG 4 WC Physics, Condensed Matter SC Physics GA 730KE UT WOS:000185829300017 ER PT J AU Sandu, T Klimeck, G Kirk, WP AF Sandu, T Klimeck, G Kirk, WP TI Off-center electron transport in resonant tunneling diodes due to incoherent scattering SO PHYSICAL REVIEW B LA English DT Article ID CURRENT-VOLTAGE CALCULATIONS; INTERFACE ROUGHNESS; DEVICES AB Coherent transport through resonant tunneling diodes at high bias is determined by the transfer of carriers described by momentum and energy from a bath in the emitter through a central resonance to the collector. Simplified treatments of coherent carrier transport assume the transverse carrier dispersions to be identical and parabolic in the emitter and central device. This results in a carrier transport that is dominated by carriers at the Gamma zone center. Other work has shown that more realistic dispersions result in off-zone center current flow. Incoherent scattering adds more degrees of freedom to match the emitter energy and momentum (E-em,k(em)) with the resonance energy and momentum (E-res,k(res)) with (DeltaE(scatt),Deltak(scatt)). It is shown analytically and numerically that this additional degree of freedom redirects carriers in energy and momentum space resulting in an off-zone center current for large voltage regions. Interface roughness, polar optical phonon, and acoustic phonon scatterings are explicitly considered. C1 Univ Texas, Dept Elect Engn, NanoFAB Ctr, Arlington, TX 76019 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Arizona, Tempe, AZ 85287 USA. RP Sandu, T (reprint author), Univ Texas, Dept Elect Engn, NanoFAB Ctr, Arlington, TX 76019 USA. RI Sandu, Titus/A-5285-2012; Klimeck, Gerhard/A-1414-2012 OI Sandu, Titus/0000-0003-0667-1115; Klimeck, Gerhard/0000-0001-7128-773X NR 29 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2003 VL 68 IS 11 AR 115320 DI 10.1103/PhysRevB.68.115320 PG 9 WC Physics, Condensed Matter SC Physics GA 730KE UT WOS:000185829300072 ER PT J AU Estabrook, FB Armstrong, JW Tinto, M Folkner, W AF Estabrook, FB Armstrong, JW Tinto, M Folkner, W TI SyZyGy: A straight interferometric spacecraft system for gravity wave observations SO PHYSICAL REVIEW D LA English DT Article ID GRAVITATIONAL-WAVES AB We consider a spaceborne gravitational wave (GW) detector formed by three spacecraft in a linear array, coherently exchanging laser beams and using the data combinations of time-delay interferometry (TDI). We previously showed how the measured time series of Doppler shifts in the six one-way laser links between spacecraft pairs in a general unequal-arm triangular configuration can be combined, using TDI, to exactly cancel the otherwise overwhelming phase noise of the lasers while retaining sensitivity to GWs. Here we apply TDI, unfolding the general triangular configuration, to the special case of a linear array of three spacecraft. We show that such an array ("SyZyGy") has, compared with an equilateral triangle GW detector of the same scale, a degraded (but non-zero) sensitivity at low frequencies [f1 ppbv only in the top 1% sample population. During TRACE- P, NH4+ dominated, followed by SO42-, Cl-, Na+, NO3-, Ca2+, and K+, in decreasing order of importance. In addition to a sea-salt origin, Cl- showed a source in urban emissions possibly related to biofuel combustion. Both sea salt and dust contributed to Mg2+. In both experiments, NH4+, SO42-, NO3-, and CO were strongly correlated, indicating that combustion was the dominant source of these species and that NH3 and other alkaline materials were in sufficient supply to neutralize H2SO4. The [NH4+] to ([NO3-] + 2[SO42-]) ratio was similar to0.70 in the two campaigns, with deviations found only in volcano plumes, whereby SO42- was found to correlate with SO2. Charge balance of the ions showed both positive and negative deviations whose magnitudes, similar to30%, provide estimates of the lower limits of unmeasured ions. Elevated NO3- and Ca2+ coexist mainly under polluted conditions, suggesting the importance of sequestering HNO3 by mineral dust. C1 Brookhaven Natl Lab, Div Atmospher Sci, Upton, NY 11973 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Acad Sinica, Environm Change Res Project, Taipei 11529, Taiwan. Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA. RP Lee, YN (reprint author), Brookhaven Natl Lab, Div Atmospher Sci, Upton, NY 11973 USA. EM ynlee@bnl.gov NR 20 TC 40 Z9 42 U1 3 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 13 PY 2003 VL 108 IS D23 AR 8646 DI 10.1029/2002JD003265 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 775AG UT WOS:000189018100001 ER PT J AU Singh, HB Salas, L Herlth, D Kolyer, R Czech, E Viezee, W Li, Q Jacob, DJ Blake, D Sachse, G Harward, CN Fuelberg, H Kiley, CM Zhao, Y Kondo, Y AF Singh, HB Salas, L Herlth, D Kolyer, R Czech, E Viezee, W Li, Q Jacob, DJ Blake, D Sachse, G Harward, CN Fuelberg, H Kiley, CM Zhao, Y Kondo, Y TI In situ measurements of HCN and CH3CN over the Pacific Ocean: Sources, sinks, and budgets SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE oxygenated organics; PAN; acetone; methanol; biogenic emissions; troposphere ID TRACE GAS MEASUREMENTS; SOLAR SPECTROSCOPIC MEASUREMENTS; TRANSFORM INFRARED-SPECTROSCOPY; VERTICAL COLUMN ABUNDANCES; HYDROGEN-CYANIDE HCN; FREE TROPOSPHERIC CO; ATMOSPHERIC CHEMISTRY; SEASONAL-VARIATIONS; NORTHERN JAPAN; INDIAN-OCEAN AB [1] We report the first in situ measurements of hydrogen cyanide (HCN) and methyl cyanide (CH3CN, acetonitrile) from the Pacific troposphere ( 0-12 km) obtained during the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) airborne mission ( February-April 2001). Mean HCN and CH3CN mixing ratios of 243 +/- 118 ( median 218) ppt and 149 +/- 56 ( median 138) ppt, respectively, were measured. These in situ observations correspond to a mean tropospheric HCN column of 4.2 x 10(15) molecules cm(-2) and a CH3CN column of 2.5 x 10(15) molecules cm(-2). This is in good agreement with the 0-12 km HCN column of 4.4 (+/- 0.6) x 10(15) molecules cm(-2) derived from infrared solar spectroscopic observations over Japan. Mixing ratios of HCN and CH3CN were greatly enhanced in pollution outflow from Asia and were well correlated with each other as well as with known tracers of biomass combustion ( e. g., CH3Cl, CO). Volumetric enhancement ( or emission) ratios (ERs) relative to CO in free tropospheric plumes, likely originating from fires, were 0.34% for HCN and 0.17% for CH3CN. ERs with respect to CH3Cl and CO in selected biomass burning ( BB) plumes in the free troposphere and in boundary layer pollution episodes are used to estimate a global BB source of 0.8 +/- 0.4 Tg (N) yr(-1) for HCN and 0.4 +/- 0.1 Tg ( N) yr(-1) for CH3CN. In comparison, emissions from industry and fossil fuel combustion are quite small (< 0.05 Tg (N) yr(-1)). The vertical structure of HCN and CH3CN indicated reduced mixing ratios in the marine boundary layer (MBL). Using a simple box model, the observed gradients across the top of the MBL are used to derive an oceanic loss rate of 8.8 x 10(-15) g (N) cm(-2) s(-1) for HCN and 3.4 x 10(-15) g ( N) cm(-2) s(-1) for CH3CN. An air-sea exchange model is used to conclude that this flux can be maintained if the oceans are undersaturated in HCN and CH3CN by 27% and 6%, respectively. These observations also correspond to an open ocean mean deposition velocity (v(d)) of 0.12 cm s(-1) for HCN and 0.06 cm s(-1) for CH3CN. It is inferred that oceanic loss is a dominant sink for these cyanides and that they deposit some 1.4 Tg ( N) of nitrogen annually to the oceans. Assuming loss to the oceans and reaction with OH radicals as the major removal processes, a mean atmospheric residence time of 5.0 months for HCN and 6.6 months for CH3CN is calculated. A global budget analysis shows that the sources and sinks of HCN and CH3CN are roughly in balance but large uncertainties remain in part due to a lack of observational data from the atmosphere and the oceans. Pathways leading to the oceanic ( and soil) degradation of these cyanides are poorly known but are expected to be biological in nature. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. MIT, Dept Earth & Planetary Sci, Cambridge, MA 02139 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92717 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Univ Calif Davis, Dept Mech & Aeronaut Engn, Davis, CA 95616 USA. Univ Tokyo, Ctr Adv Sci & Technol, Meguro Ku, Tokyo 1538904, Japan. RP NASA, Ames Res Ctr, Mail Stop 245-5,21 Langley Blvd, Moffett Field, CA 94035 USA. EM hanwant.B.Singh@nasa.gov; qli@io.harvard.edu; djj@io.harvard.edu; drblake@uci.edu; g.w.sachse@larc.nasa.gov; fuelberg@met.fsu.edu; yzhao@mae.ucdavis.edu; kondo@atmos.rcast.u-tokyo.ac.jp RI Kondo, Yutaka/D-1459-2012 NR 67 TC 91 Z9 92 U1 7 U2 27 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 13 PY 2003 VL 108 IS D20 AR 8795 DI 10.1029/2002JD003006 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 775AD UT WOS:000189017800001 ER PT J AU Davies, AG AF Davies, AG TI Volcanism on Io: Estimation of eruption parameters from Galileo NIMS data SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE Io; volcanism; Galilean satellites; lava; thermal; remote sensing ID INFRARED MAPPING SPECTROMETER; LANDSAT THEMATIC MAPPER; HAWAIIAN LAVA FLOWS; JUPITERS MOON IO; KILAUEA VOLCANO; SILICATE VOLCANISM; HOT-SPOTS; THERMAL EMISSION; ACTIVE VOLCANISM; LASCAR VOLCANO AB [1] Galileo Near Infrared Mapping Spectrometer (NIMS) data of volcanic thermal emission are analyzed to determine the power output of a number of Ionian volcanoes, from which are calculated volumetric eruption rates. A two-temperature model is used to determine surface temperatures and power output. Portions of Prometheus and six other volcanoes are found to be in excess of 1100 K: areas of Prometheus are at temperatures close to 1500 K. These are minimum eruption temperatures and are consistent with basaltic silicate volcanism. For the 14 volcanoes in G1INNSPEC01, volumetric eruption rates ( E) are constrained between 3 and 300 m(3)/s for basaltic and ultramafic compositions. Actual E values lie between these limits. The small crack fractions ( hot area to warm area ratio) implied from these fits are indicative of a relatively quiescent eruption style, such as the emplacement of a pahoehoe or a-a flow field. The volumetric eruption rates derived from the NIMS data are greater than those observed in similar styles of volcanism on Earth. It is apparent that for similar eruption styles, the areal extent of activity is greater on Io than on Earth. Derived flow thicknesses range from 0.1 to 13 m. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Davies, AG (reprint author), CALTECH, Jet Prop Lab, MS 183-501,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Ashley.Davies@jpl.nasa.gov NR 73 TC 22 Z9 22 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-PLANET JI J. Geophys. Res.-Planets PD SEP 13 PY 2003 VL 108 IS E9 AR 5106 DI 10.1029/2001JE001509 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 775AY UT WOS:000189019600001 ER PT J AU Ieda, A Shue, JH Liou, K Ohtani, SI Meng, CI Fairfield, DH Mukai, T Saito, Y Machida, S Nagai, T Parks, GK AF Ieda, A Shue, JH Liou, K Ohtani, SI Meng, CI Fairfield, DH Mukai, T Saito, Y Machida, S Nagai, T Parks, GK TI Quiet time magnetotail plasma flow: Coordinated Polar ultraviolet images and Geotail observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE fast flows; aurora; quiet time; plasma sheet; magnetotail ID SHEET BOUNDARY-LAYER; AURORAL BRIGHTENINGS; ION DISTRIBUTIONS; MAGNETIC ACTIVITY; NEUTRAL LINE; AVERAGE; MODEL; RECONNECTION; DYNAMICS; BURSTS AB [ 1] A search for fast flows in the plasma sheet during quiet times was conducted in order to further test the previously found close association between fast flows and auroral brightenings. We first identified "quiet intervals'' of at least 30-min duration in the Polar ultraviolet global images of auroras. During 16 months of Polar observations from January 1997 through April 1998, 41 quiet intervals were identified when Geotail was between 8 and 31 RE down the tail and within 10 RE of the midnight meridian. Fast flows were more rare during the quiet intervals than at other times. For 4 of the 41 intervals identified, Geotail detected flows faster than 300 km s(-1) in the plasma sheet. All the four flows were earthward parallel flows accompanied by northward magnetic field beyond 20 RE, and there were no perpendicular flows faster than 300 km s(-1). To understand the nature of the fast ( but not perpendicular) flows during the quiet intervals, an earthward flow at 21 RE down the tail was studied in detail. The plasma beta was higher than unity during the earthward flow, but the fastest ion velocity moments consisted of the two counterstreaming components flowing along the magnetic field, a characteristic known to define the plasma sheet boundary layer. Our results further support the close association between auroral brightenings and clear fast flows as seen in previous studies, because no perpendicular fast flows were found during quiet intervals. Since some perpendicular flows slower than 300 km s(-1) were found beyond -20 R-E down the tail, a velocity of -300 km s(-1) appears to statistically make a difference in the geoeffectiveness of perpendicular flows. C1 Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Kyoto Univ, Dept Geophys, Kyoto 60601, Japan. Tokyo Inst Technol, Dept Earth & Planetary Sci, Tokyo 1528551, Japan. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RP Ieda, A (reprint author), Nagoya Univ, Solar Terr Environm Lab, 3-13 Honohara, Aichi 4428507, Japan. EM ieda@stelab.nagoya-u.ac.jp RI Ohtani, Shinichi/E-3914-2016; Liou, Kan/C-2089-2016 OI Ohtani, Shinichi/0000-0002-9565-6840; Liou, Kan/0000-0001-5277-7688 NR 25 TC 6 Z9 6 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD SEP 13 PY 2003 VL 108 IS A9 AR 1345 DI 10.1029/2002JA009739 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 775BQ UT WOS:000189021200001 ER PT J AU Egbert, GD Ray, RD AF Egbert, GD Ray, RD TI Semi-diurnal and diurnal tidal dissipation from TOPEX/Poseidon altimetry SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INTERNAL TIDES; OCEAN TIDE; DEEP-OCEAN; ENERGY; MODEL; FLUX AB [1] Tidal energy dissipation is estimated for eight semi-diurnal and diurnal constituents using a global inverse solution constrained by TOPEX/Poseidon altimeter data. Very similar spatial patterns are obtained for all semi-diurnal constituents, with about one third of the total dissipation occurring in the deep ocean over rough topography. Maps for diurnal constituents are also similar amongst themselves, but quite different from the semi-diurnal results. For diurnals a smaller fraction of dissipation, roughly 10%, occurs in the deep ocean. Much of the difference can be explained by the very different spatial pattern of diurnal and semi-diurnal tidal currents. The lack of free internal waves at frequencies poleward of 30degrees at diurnal frequencies also probably plays a role, limiting the effectiveness of baroclinic conversion as an energy sink for barotropic diurnal tides. C1 Oregon State Univ, Coll Ocean & Atmospher Sci, Corvallis, OR 97331 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Egbert, GD (reprint author), Oregon State Univ, Coll Ocean & Atmospher Sci, Ocean Adm Bldg 104, Corvallis, OR 97331 USA. EM egbert@oce.orst.edu; richard.ray@gsfc.nasa.gov RI Ray, Richard/D-1034-2012 NR 17 TC 79 Z9 80 U1 0 U2 17 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 12 PY 2003 VL 30 IS 17 AR 1907 DI 10.1029/2003GL017676 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 774ZL UT WOS:000189016200004 ER PT J AU Kortz, KM Grosfils, EB Sakimoto, SEH AF Kortz, KM Grosfils, EB Sakimoto, SEH TI Emplacement of long lava flows within a graben network in Radunitsa Labyrinthus, Carson quadrangle, Venus SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANALOG EXPERIMENTS; FLOOD-BASALT; MORPHOLOGY; PREDICTIONS; RHEOLOGY; CANALI; FIELDS; MODEL; MAGMA; TUBES AB [1] Radar bright lava flows in the Radunitsa Labyrinthus region of the Carson quadrangle on Venus traveled up to 200 km within a network of orthogonal grabens. Using a cooling model for basalt to evaluate the graben-channelized lava flow emplacement process, we demonstrate that the lava flows would need to either be very thin (<5 m) or have a very low effusion rate (<50 m(3)s(-1)) in order to cease flow within the observed 200 km solely by cooling. Neither condition is likely given our mapping observations and what is known about long lava flow emplacement on Earth, leading us to conclude that lava flow emplacement in Radunitsa Labyrinthus was probably supply-rather than cooling-limited. C1 Pomona Coll, Dept Geol, Claremont, CA 91711 USA. NASA, Goddard Space Flight Ctr, Geodynam Branch, GEST, Greenbelt, MD 20771 USA. RP Kortz, KM (reprint author), Community Coll Rhode Isl, Dept Phys, Lincoln, RI 02865 USA. EM kkortz@ccri.edu NR 27 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 12 PY 2003 VL 30 IS 17 AR 1908 DI 10.1029/2003GL017471 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 774ZL UT WOS:000189016200003 ER PT J AU O'Neill, NT Eck, TF Smirnov, A Holben, BN Thulasiraman, S AF O'Neill, NT Eck, TF Smirnov, A Holben, BN Thulasiraman, S TI Spectral discrimination of coarse and fine mode optical depth SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE Sun photometry; aerosol; optical depth; fine mode; coarse mode; cloud screening ID SIZE DISTRIBUTION; AEROSOL; RETRIEVAL; AERONET AB [1] The recognition that the aerosol particle size distribution (PSD) is effectively bimodal permits the extraction of the fine and coarse mode optical depths (tau(f) and tau(c)) from the spectral shape of the total aerosol optical depth (tau(a) = tau(f) + tau(c)). This purely optical technique avoids intermediate computations of the PSD and yields a direct optical output that is commensurate in complexity with the spectral information content of tau(a). The separation into tau(f) and tau(c) is a robust process and yields aerosol optical statistics, which are more intrinsic than those, obtained from a generic analysis of tau(a). Partial (optical) validation is provided by ( 1) demonstrating the physical coherence of the simple model employed, ( 2) demonstrating that tau(c) variation is coherent with photographic evidence of thin cloud events and that tau(f) variation is coherent with photographic evidence of clear sky and haze events, and ( 3) showing that the retrieved values of tau(f) and tau(c) are well-correlated, if weakly biased, relative to formal inversions of combined solar extinction and sky radiance data. The spectral inversion technique permitted a closer scrutiny of a standard ( temporally based) cloud-screening algorithm. Perturbations of monthly or longer-term statistics associated with passive or active shortcomings of operational cloud screening were inferred to be small to occasionally moderate over a sampling of cases. Diurnal illustrations were given where it was clear that such shortcomings can have a significant impact on the interpretation of specific events; ( 1) commission errors in tau(f) due to the exclusion of excessively high-frequency fine mode events and ( 2) omission errors in tau(c) due to the inclusion of insufficiently high-frequency thin homogeneous cloud events. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Univ Sherbrooke, Ctr Applicat & Rech Teledetect, 2500 Bd Univ, Sherbrooke, PQ J1K 2R1, Canada. EM noneill@courrier.usherb.ca; teck@ltpmail.gsfc.nasa.gov; asmirnov@ltpmail.gsfc.nasa.gov; brent@aeronet.gsfc.nasa.gov; Thulasiraman.Srinivasan@Usherbrooke.Ca RI Smirnov, Alexander/C-2121-2009; ECK, THOMAS/D-7407-2012 OI Smirnov, Alexander/0000-0002-8208-1304; NR 11 TC 233 Z9 242 U1 0 U2 20 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 12 PY 2003 VL 108 IS D17 AR 4559 DI 10.1029/2002JD002975 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 774ZV UT WOS:000189017000001 ER PT J AU Potter, C Klooster, S Steinbach, M Tan, P Kumar, V Shekhar, S Nemani, R Myneni, R AF Potter, C Klooster, S Steinbach, M Tan, P Kumar, V Shekhar, S Nemani, R Myneni, R TI Global teleconnections of climate to terrestrial carbon flux SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE carbon flux; global model; ENSO ID SEA-SURFACE TEMPERATURE; NET PRIMARY PRODUCTION; NORTH-ATLANTIC OSCILLATION; NINO-SOUTHERN-OSCILLATION; BRAZILIAN AMAZON REGION; INTERANNUAL VARIABILITY; DIOXIDE FLUXES; LEAF-AREA; PRECIPITATION; SATELLITE AB [1] We have applied association analysis to 17 years of climate index observations and predicted net ecosystem production on land to infer short-term ( monthly to yearly) teleconnections between atmosphere-ocean climate forcing and terrestrial carbon cycles. The analysis suggests that on a global level, climate indices can be significantly correlated to net ecosystem carbon fluxes over more than 58% of the nondesert/ice-covered land surface, commonly with a lead period of 2-6 months. The Southern Oscillation ( SO) and Arctic Oscillation (AO) indices explain nearly equal portions of these significantly correlated area carbon fluxes. These significant teleconnections detected between surface climate and seasonal carbon gain or loss in terrestrial vegetation offer important capabilities for making inferences about the variability in the terrestrial carbon cycle of natural and agricultural ecosystems worldwide. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Calif State Univ Monterey Bay, Earth Syst Sci & Policy Inst, Seaside, CA 93955 USA. Univ Minnesota, Dept Comp Sci & Engn, Minneapolis, MN 55455 USA. Boston Univ, Dept Geog, Boston, MA 02215 USA. Univ Montana, Sch Forestry, Missoula, MT 59812 USA. RP Potter, C (reprint author), NASA, Ames Res Ctr, Mail Stop 242-4, Moffett Field, CA 94035 USA. EM potter@gaia.arc.nasa.gov RI Myneni, Ranga/F-5129-2012 NR 54 TC 30 Z9 30 U1 0 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 12 PY 2003 VL 108 IS D17 AR 4556 DI 10.1029/2002JD002979 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 774ZV UT WOS:000189017000002 ER PT J AU Vay, SA Woo, JH Anderson, BE Thornhill, KL Blake, DR Westberg, DJ Kiley, CM Avery, MA Sachse, GW Streets, DG Tsutsumi, Y Nolf, SR AF Vay, SA Woo, JH Anderson, BE Thornhill, KL Blake, DR Westberg, DJ Kiley, CM Avery, MA Sachse, GW Streets, DG Tsutsumi, Y Nolf, SR TI Influence of regional-scale anthropogenic emissions on CO2 distributions over the western North Pacific SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE carbon dioxide; Asian emissions; CO2 flux ID TROPOSPHERIC CARBON-DIOXIDE; LONG-RANGE TRANSPORT; PEM-WEST; ATMOSPHERIC CO2; AIRBORNE OBSERVATIONS; HYDROCARBON RATIOS; AIR MASSES; JAPAN; ASIA; BASIN AB [ 1] We report here airborne measurements of atmospheric CO2 over the western North Pacific during the March-April 2001 Transport and Chemical Evolution over the Pacific ( TRACE-P) mission. The CO2 spatial distributions were notably influenced by cyclogenesis-triggered transport of regionally polluted continental air masses. Examination of the CO2 to C2H2/CO ratio indicated rapid outflow of combustion-related emissions in the free troposphere below 8 km. Although the highest CO2 mixing ratios were measured within the Pacific Rim region, enhancements were also observed further east over the open ocean at locations far removed from surface sources. Near the Asian continent, discrete plumes encountered within the planetary boundary layer contained up to 393 ppmv of CO2. Coincident enhancements in the mixing ratios of C2Cl4, C2H2, and C2H4 measured concurrently revealed combustion and industrial sources. To elucidate the source distributions of CO2, an emissions database for Asia was examined in conjunction with the chemistry and 5-day backward trajectories that revealed the WNW/W sector of northeast Asia was a major contributor to these pollution events. Comparisons of NOAA/CMDL and JMA surface data with measurements obtained aloft showed a strong latitudinal gradient that peaked between 35degrees and 40degreesN. We estimated a net CO2 flux from the Asian continent of approximately 13.93 Tg C day(-1) for late winter/early spring with the majority of the export ( 79%) occurring in the lower free troposphere ( 2-8 km). The apportionment of the flux between anthropogenic and biospheric sources was estimated at 6.37 Tg C day(-1) and 7.56 Tg C day(-1), respectively. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Iowa, Ctr Global & Reg Environm Res, Iowa City, IA 52242 USA. Sci Applicat Int Corp, Hampton, VA 23666 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Argonne Natl Lab, Decis & Informat Sci Div, Argonne, IL 60439 USA. Japan Meteorol Agcy, Div Atmospher Environm, Chiyoda Ku, Tokyo 1008122, Japan. Comp Sci Corp, Hampton, VA 23666 USA. RP NASA, Langley Res Ctr, MS 483, Hampton, VA 23681 USA. EM a.vay@larc.nasa.gov; woojh21@cgrer.uiowa.edu; b.e.anderson@larc.nasa.gov; k.l.thornhill@larc.nasa.gov; dblake@orion.oac.uci.edu; d.j.westberg@larc.nasa.gov; ckiley@met.fsu.edu; m.a.avery@larc.nasa.gov; g.w.sachse@larc.nasa.gov; dstreets@anl.gov; y-tsutsumi@met.kishou.go.jp; snolf@csc.com NR 47 TC 44 Z9 44 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 12 PY 2003 VL 108 IS D20 AR 8801 DI 10.1029/2002JD003094 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 775AC UT WOS:000189017700001 ER PT J AU Jones, GH Balogh, A Smith, EJ AF Jones, GH Balogh, A Smith, EJ TI Solar magnetic field reversal as seen at Ulysses SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HELIOSPHERIC CURRENT SHEET; SECTOR STRUCTURE; WIND; MAXIMUM; EVOLUTION; ROTATION AB The rapid motion of the Ulysses spacecraft from high southern to high northern latitudes in 2000-2001 provided an excellent opportunity to make inferences regarding the solar magnetic dipole's behaviour around solar maximum. A simple dipole model is fitted to Ulysses measurements of the polarity of the heliospheric magnetic field mapped back to the solar wind source surface. Although higher order components of the field are ignored, the gradual reversal in orientation of the dipole field component can be followed during solar maximum, with the dipole axis crossing the solar equator during early 2000-early 2001. The dipole appears to exhibit a rotation at a slower rate than the Carrington frame of reference, similar to previous measurements made around solar maximum in the solar equatorial regions. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Space & Atmospher Phys Grp, London SW7 2BW, England. RP Jones, GH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM g.h.jones@imperial.ac.uk RI Jones, Geraint/C-1682-2008; OI Jones, Geraint/0000-0002-5859-1136 NR 19 TC 29 Z9 29 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 11 PY 2003 VL 30 IS 19 AR 8028 DI 10.1029/2003GL017204 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 774ZN UT WOS:000189016400004 ER PT J AU Lin, NG Kellogg, PJ MacDowall, RJ McComas, DJ Balogh, A AF Lin, NG Kellogg, PJ MacDowall, RJ McComas, DJ Balogh, A TI VLF wave activity in the solar wind and the photoelectron effect in electric field measurements: Ulysses observations SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID HEAT-FLUX AB We present observations of very low frequency (VLF) waves (0.2 to 448 Hz) made by Ulysses during the solar maximum and compare the observations with those obtained when the solar activity was approaching a minimum. The occurrences and properties of the waves are found to be similar during the solar maximum and solar minimum periods for slow and intermediate speed solar wind. The maximum intensities of the electromagnetic waves for the two solar cycle periods are comparable. These similarities suggest that the plasma conditions for the waves' excitation are similar for the slow and intermediate solar wind in both solar maximum and minimum phases. It is also found that the electric field noise detected in the low band channels, which are measuring less than 10 Hz signals, is contaminated by the spin modulation of the electric field caused by the photoelectron cloud around the spacecraft, especially when the ambient plasma density is low. This effect enhances with increasing solar aspect angle. C1 Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. SW Res Inst, San Antonio, TX 78228 USA. RP Lin, NG (reprint author), Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. RI MacDowall, Robert/D-2773-2012 NR 9 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 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 11 PY 2003 VL 30 IS 19 AR 8029 DI 10.1029/2003GL017244 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 774ZN UT WOS:000189016400005 ER PT J AU Reisenfeld, DB Gosling, JT Forsyth, RJ Riley, P St Cyr, OC AF Reisenfeld, DB Gosling, JT Forsyth, RJ Riley, P St Cyr, OC TI Properties of high-latitude CME-driven disturbances during Ulysses second northern polar passage SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CORONAL MASS EJECTIONS; SOLAR-WIND; MISSION; SHOCK AB Ulysses observed five coronal mass ejections (CMEs) and their associated disturbances while the spacecraft was immersed in the polar coronal hole (CH) flow above 70degrees N in late 2001. Of these CMEs, two were very fast (>850 km s(-1)) driving strong shocks in the wind ahead, and two others were over-expanding. The two fast CMEs were observed leaving the Sun by LASCO/SOHO, and were observed in the ecliptic by Genesis and ACE. These were large events, spanning at least from the northern heliospheric pole to the ecliptic. One-dimensional hydrodynamic simulations indicate that these could be described as overpressured CMEs launched from the Sun at speeds initially faster than ambient, but then decelerating to the ambient solar wind speed as they propagated outward. The two over-expanding CMEs mark their first occurrence since Ulysses' first orbit when such CMEs were only observed in polar CH flow. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Imperial Coll Space & Atmospher Phys, Blackett Lab, London SW7 2BW, England. Sci Applicat Int Corp, San Diego, CA 92121 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20770 USA. RP Reisenfeld, DB (reprint author), Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. RI Reisenfeld, Daniel/F-7614-2015 NR 16 TC 29 Z9 29 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 11 PY 2003 VL 30 IS 19 AR 8031 DI 10.1029/2003GL017155 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 774ZN UT WOS:000189016400003 ER PT J AU Bean, BD Mollner, AK Nizkorodov, SA Nair, G Okumura, M Sander, SP Peterson, KA Francisco, JS AF Bean, BD Mollner, AK Nizkorodov, SA Nair, G Okumura, M Sander, SP Peterson, KA Francisco, JS TI Cavity ringdown spectroscopy of cis-cis HOONO and the HOONO/HONO2 branching ratio in the reaction OH+NO2+M SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID LASER-INDUCED FLUORESCENCE; QUADRATIC CONFIGURATION-INTERACTION; VOLATILE ORGANIC-COMPOUNDS; PEROXYNITROUS ACID HOONO; PHASE CHEMICAL MECHANISM; POTENTIAL-ENERGY SURFACE; HIGH-PRESSURE FLOW; GAS-PHASE; NITRIC-ACID; AB-INITIO AB The termolecular association reaction OH + NO2 + M was studied in a low-pressure discharge flow reactor, and both HONO2 and HOONO products were detected by infrared cavity ringdown spectroscopy (IR-CRDS). The absorption spectrum of the fundamental nu(1) band of the cis-cis isomer of HOONO (pernitrous or peroxynitrous acid) was observed at 3306 cm(-1), in good agreement with matrix isolation studies and ab initio predictions. The rotational contour of this band was partially resolved at I cm-1 resolution and matched the profile predicted by ab initio calculations. The integrated absorbances of the nu(1) bands of the cis-cis HOONO and HONO2 products were measured as a function of temperature and pressure. These were converted to product branching ratios by scaling the experimentally observed absorbances with ab initio integrated cross sections for HOONO and HONO2 computed at the CCSD(T)/cc-pVTZ level. The product branching ratio for cis-cis HOONO to HONO, was 0.075 +/- 0.020(2sigma) at room temperature in a 20 Torr mixture of He/Ar/N, buffer gas. The largest contribution to the uncertainty is from the ab initio ratio of the absorption cross sections, computed in the double harmonic approximation, which is estimated to be accurate to within 20%. The branching ratio decreased slightly with temperature over the range 270 to 360 K at 20 Torr. Although trans-perp HOONO was not observed, its energy was computed at the CCSD(T)/cc-pVTZ level to be E-0 = +3.4 kcal/mol relative to the cis-cis isomer. Statistical rate calculations showed that the conformers of HOONO should reach equilibrium on the time scale of this exeriment. These results suggested that essentially all isomers had converted to cis-cis HOONO; thus, the reported branching ratio is a lower bound for and may represent the entire HOONO yield. C1 CALTECH, Arthur Amos Noyes Lab Chem Phys, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, NASA, Pasadena, CA 91109 USA. Washington State Univ, Dept Chem, Pullman, WA 99164 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. RP Okumura, M (reprint author), CALTECH, Arthur Amos Noyes Lab Chem Phys, MC 127-72, Pasadena, CA 91125 USA. RI Okumura, Mitchio/I-3326-2013; Nizkorodov, Sergey/I-4120-2014 OI Okumura, Mitchio/0000-0001-6874-1137; Nizkorodov, Sergey/0000-0003-0891-0052 NR 85 TC 42 Z9 42 U1 1 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD SEP 11 PY 2003 VL 107 IS 36 BP 6974 EP 6985 DI 10.1021/jp034407c PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 719YV UT WOS:000185233400010 ER PT J AU Gutsev, GL Bauschlicher, CW AF Gutsev, GL Bauschlicher, CW TI Electron affinities, ionization energies, and fragmentation energies of Fe-n clusters (n=2-6): A density functional theory study SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID SMALL IRON CLUSTERS; TRANSITION-METAL CLUSTERS; COLLISION-INDUCED DISSOCIATION; CARBON NANOTUBE PRODUCTION; GAUSSIAN-BASIS SETS; PHOTOELECTRON-SPECTROSCOPY; MAGNETIC-PROPERTIES; GROUND-STATE; FERROMAGNETIC CLUSTERS; BINDING-ENERGIES AB The electronic and geometrical structures of the ground and exited states of Fe-n, Fe-n(-), and Fe-n(+) are computed by density functional theory. Because the assignment of the ground states of Fe-3, Fe-3(-), Fe-4, and Fe-4(-) is controversial, these systems are studied using several different functionals. It appears that the LSDA and B3LYP methods do not work well for iron clusters and should be avoided. The number of unpaired electrons in the neutral ground states is 6(Fe-2), 10(Fe-4) 14(Fe-4), 16(Fe-5), and 20(Fe-6). The number of unpaired electrons in the ground states of the anions and cations differ by one from the corresponding neutral, except for Fe-4(+), which has three fewer unpaired electrons than Fe-4. The computed DFT adiabatic electron affinities and ionization potentials of the neutral clusters are in good agreement with experiment. Fragmentation energies are in qualitative agreement with experiment, where the error is about 1 eV for the dissociation energy of the iron dimer. The natural bond analysis allows one to qualitatively understand the nature of high local magnetic moments at iron sites and their evolution from Fe-2 to Fe-6. C1 NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Space Technol Div, Moffett Field, CA 94035 USA. RP Gutsev, GL (reprint author), NASA, Ames Res Ctr, ELORET Corp, Mail Stop 230-3, Moffett Field, CA 94035 USA. EM ggutsev@mail.arc.nasa.gov NR 83 TC 127 Z9 130 U1 2 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD SEP 11 PY 2003 VL 107 IS 36 BP 7013 EP 7023 DI 10.1021/jp030288p PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 719YV UT WOS:000185233400014 ER PT J AU Barstow, MA Good, SA Burleigh, MR Hubeny, I Holberg, JB Levan, AJ AF Barstow, MA Good, SA Burleigh, MR Hubeny, I Holberg, JB Levan, AJ TI A comparison of DA white dwarf temperatures and gravities from FUSE Lyman line and ground-based Balmer line observations SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars : atmospheres; white dwarfs; ultraviolet : stars ID ULTRAVIOLET EXPLORER SURVEY; ALL-SKY SURVEY; MASS-DISTRIBUTION; LUMINOSITY FUNCTION; ROSAT; EVOLUTION; SPECTROSCOPY; SPECTROGRAPH; ABUNDANCES; SAMPLE AB The observation of the strengths and profiles of the hydrogen Balmer absorption series is an established technique for determining the effective temperature and surface gravity of hot H-rich white dwarf stars. In principle, the Lyman series lines should be equally useful but, lying in the far-ultraviolet (FUV), are only accessible from space. Nevertheless, there are situations (for example, where the optical white dwarf spectrum is highly contaminated by the presence of a companion) in which use of the Lyman series may be essential. Therefore, it is important to establish whether or not the Lyman lines provide an equally valid means of measurement. We have already made a first attempt to study this problem, comparing Lyman line measurements from a variety of FUV instruments with ground-based Balmer line studies. Within the measurement uncertainties, we found the results from each line series to be broadly in agreement. However, we noted a number of potential systematic effects that could bias either measurement. With the availability of the Far Ultraviolet Spectroscopic Explorer (FUSE) data archive and observations from our own Guest Observer programmes, we now have an opportunity to examine the use of the Lyman series in more detail from observations of 16 DA white dwarfs. Here we have data produced by a single instrument and processed with a uniform data reduction pipeline, eliminating some of the possible systematic differences between observations of the same or different stars. We have also examined the scatter in values derived from multiple observations of the same star, which is significant. The new results partially reproduce the earlier study, showing that Balmer and Lyman line determined temperatures are in good agreement up to similar to50 000 K. However, above this value there is an increasing systematic difference between the Lyman and Balmer line results, the former yielding the higher temperature. At the moment, there is no clear explanation of this effect but we think that it is most likely associated with deficiencies in the detailed physics incorporated into the stellar model atmosphere calculations. Even so, the data do demonstrate that, for temperatures below 50 000 K, the Lyman lines give reliable results. Furthermore, for the hotter stars, a useful empirical calibration of the relationship between the Lyman and Balmer measurements has been obtained, which can be applied to other FUSE observations. C1 Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20711 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. RP Barstow, MA (reprint author), Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England. NR 37 TC 38 Z9 38 U1 0 U2 0 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 11 PY 2003 VL 344 IS 2 BP 562 EP 574 DI 10.1046/j.1365-8711.2003.06838.x PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 719EP UT WOS:000185190900026 ER PT J AU Bolotnikov, AE Chen, CMH Cook, WR Harrison, FA Kuvvetli, I Schindler, SM Stahle, CM Parker, BH AF Bolotnikov, AE Chen, CMH Cook, WR Harrison, FA Kuvvetli, I Schindler, SM Stahle, CM Parker, BH TI The effect of cathode bias (field effect) on the surface leakage current of CdZnTe detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE CdZnTe; field-effect; pixel detectors ID PIXEL DETECTORS; CONTACTS; PASSIVATION AB Surface resistivity is an important parameter of multi-electrode CZT detectors such as coplanar-grid, strip, or pixel detectors. Low surface resistivity results in a high leakage current and affects the charge collection efficiency in the areas near contacts. Thus, it is always desirable to have the surface resistivity of the detector as high as possible. In the past the most significant efforts were concentrated to develop passivation techniques for CZT detectors. However, as we found, the field-effect caused by a bias applied on the cathode can significantly reduce the surface resistivity even though the detector surface was carefully passivated. In this paper we illustrate that the field-effect is a common feature of the CZT multi-electrode detectors, and discuss how to take advantage of this effect to improve the surface resistivity of CZT detectors. (C) 2003 Published by Elsevier Science B.V. C1 CALTECH, Pasadena, CA 91125 USA. Danish Space Res Inst, Copenhagen, Denmark. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Chen, CMH (reprint author), CALTECH, Pasadena, CA 91125 USA. NR 15 TC 16 Z9 16 U1 0 U2 14 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 SEP 11 PY 2003 VL 510 IS 3 BP 300 EP 308 DI 10.1016/S0168-9002(03)01730-3 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 718TR UT WOS:000185163000011 ER PT J AU Luhman, ML Satyapal, S Fischer, J Wolfire, MG Sturm, E Dudley, CC Lutz, D Genzel, R AF Luhman, ML Satyapal, S Fischer, J Wolfire, MG Sturm, E Dudley, CC Lutz, D Genzel, R TI The [C II] 158 micron line deficit in ultraluminous infrared galaxies revisited SO ASTROPHYSICAL JOURNAL LA English DT Review DE galaxies : high-redshift; galaxies : ISM; galaxies : starburst; infrared : galaxies; ISM : lines and bands ID POLYCYCLIC AROMATIC-HYDROCARBONS; SPACE-OBSERVATORY MEASUREMENTS; LONG-WAVELENGTH SPECTROMETER; ACTIVE GALACTIC NUCLEI; ISO-LWS SPECTROSCOPY; INTERSTELLAR-MEDIUM; PHOTODISSOCIATION REGIONS; PHYSICAL CONDITIONS; LUMINOUS GALAXIES; IRAS OBSERVATIONS AB We present a study of the [ C II] 157.74 mum fine- structure line in a sample of 15 ultraluminous infrared ( IR) galaxies ( IR luminosity L-IR greater than or equal to 10(12) L.; ULIRGs) using the Long Wavelength Spectrometer ( LWS) on the Infrared Space Observatory ( ISO). We confirm the observed order of magnitude deficit ( compared to normal and starburst galaxies) in the strength of the [ C ii] line relative to the far- infrared ( FIR) dust continuum emission found in our initial report, but here with a sample that is twice as large. This result suggests that the deficit is a general phenomenon affecting 4 out of 5 ULIRGs. We present an analysis using observations of generally acknowledged photodissociation region ( PDR) tracers ([ C ii], [ O i] 63 and 145 mum, and FIR continuum emission), which suggests that a high ultraviolet flux G(0) incident on a moderate density n PDR could explain the deficit. However, comparisons with other ULIRG observations, including CO ( 1 - 0), [ C i] ( 1 - 0), and 6.2 mum polycyclic aromatic hydrocarbon ( PAH) emission, suggest that high G(0) = n PDRs alone cannot produce a self- consistent solution that is compatible with all of the observations. We propose that non- PDR contributions to the FIR continuum can explain the apparent [ C ii] deficiency. Here, unusually high G(0) and/ or n physical conditions in ULIRGs as compared to those in normal and starburst galaxies are not required to explain the [ C ii] deficit. Dust- bounded photoionization regions, which generate much of the FIR emission but do not contribute significant [ C ii] emission, offer one possible physical origin for this additional nonPDR component. Such environments may also contribute to the observed suppression of FIR fine- structure emission from ionized gas and PAHs, as well as the warmer FIR colors found in ULIRGs. The implications for observations at higher redshifts are also revisited. C1 USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. RP Luhman, ML (reprint author), Inst Def Anal, 4850 Mark Ctr Dr, Alexandria, VA 22311 USA. NR 103 TC 126 Z9 126 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2003 VL 594 IS 2 BP 758 EP 775 DI 10.1086/376965 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 720JL UT WOS:000185257600009 ER PT J AU Becker, W Swartz, DA Pavlov, GG Elsner, RF Grindlay, J Mignani, R Tennant, AF Backer, D Pulone, L Testa, V Weisskopf, MC AF Becker, W Swartz, DA Pavlov, GG Elsner, RF Grindlay, J Mignani, R Tennant, AF Backer, D Pulone, L Testa, V Weisskopf, MC TI Chandra X-ray observatory observations of the globular cluster M28 and its millisecond pulsar PSR B1821-24 SO ASTROPHYSICAL JOURNAL LA English DT Article DE globular clusters : individual (M28); pulsars : general; stars : neutron; X-rays : stars ID ACCRETING NEUTRON-STARS; CATACLYSMIC VARIABLES; EMISSION; NGC-6397; QUIESCENCE; DISCOVERY; GALAXY; CORE; ATMOSPHERES; PHOTOMETRY AB We report here the results of the first Chandra X- Ray Observatory observations of the globular cluster M28 ( NGC 6626). We detect 46 X- ray sources, of which 12 lie within 1 core radius of the center. We show that the apparently extended X- ray core emission seen with the ROSAT HRI is due to the superposition of multiple discrete sources, for which we determine the X- ray luminosity function down to a limit of about 6 x 1030 ergs s(-1). We measure the radial distribution of the X- ray sources and fit it to a King profile finding a core radius of r(c), x approximate to 1 1". We measure for the first time the unconfused phase- averaged X- ray spectrum of the 3.05 ms pulsar B1821 - 24 and find that it is best described by a power law with photon index Gamma similar or equal to 1.2. We find marginal evidence of an emission line centered at 3.3 keV in the pulsar spectrum, which could be interpreted as cyclotron emission from a corona above the pulsar's polar cap if the magnetic field is strongly different from a centered dipole. The unabsorbed pulsar flux in the 0.5 - 8.0 keV band is approximate to 3. 5 x 10(-13) ergs s(-1) cm(-2). We present spectral analyses of the five brightest unidentified sources. Based on the spectral parameters of the brightest of these sources, we suggest that it is a transiently accreting neutron star in a low- mass X- ray binary, in quiescence. Fitting its spectrum with a hydrogen neutron star atmosphere model yields the effective temperature T-eff(infinity) = 90(-10)(+30) eV and the radius R-NS(infinity) = 14.5(-3.8)(+6.9) km. In addition to the resolved sources, we detect fainter, unresolved X- ray emission from the central core. Using the Chandra- derived positions, we also report on the result of searching archival Hubble Space Telescope data for possible optical counterparts. C1 Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. NASA, USRA, Dept Space Sci, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Penn State Univ, Davey Lab 525, University Pk, PA 16802 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. European So Observ, D-85740 Garching, Germany. Univ Calif Berkeley, Berkeley, CA 94720 USA. Osserv Astron Roma, INAF, I-00040 Monte Porzio Catone, Italy. RP Becker, W (reprint author), Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. OI Pulone, Luigi/0000-0002-5285-998X; Testa, Vincenzo/0000-0003-1033-1340 NR 52 TC 74 Z9 74 U1 0 U2 5 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2003 VL 594 IS 2 BP 798 EP 811 DI 10.1086/376967 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 720JL UT WOS:000185257600011 ER PT J AU Freyer, T Hensler, G Yorke, HW AF Freyer, T Hensler, G Yorke, HW TI Massive stars and the energy balance of the interstellar medium. I. The impact of an isolated 60 M-circle dot star SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; HII regions; hydrodynamics; instabilities; ISM : bubbles; ISM : structure ID WIND-BLOWN BUBBLES; WOLF-RAYET STARS; STRONG DENSITY GRADIENTS; TWO-DIMENSIONAL MODELS; SELF-SIMILAR EVOLUTION; STELLAR WIND; PLANETARY-NEBULAE; DIFFUSE NEBULAE; DYNAMICAL EVOLUTION; PROTOSTELLAR DISKS AB We present results of numerical simulations carried out with a two- dimensional radiation hydrodynamics code in order to study the impact of massive stars on their surrounding interstellar medium. This first paper deals with the evolution of the circumstellar gas around an isolated 60 M. star. The interaction of the photoionized H ii region with the stellar wind bubble forms a variety of interesting structures like shells, clouds, fingers, and spokes. These results demonstrate that complex structures found in H ii regions are not necessarily relics from the time before the gas became ionized but may result from dynamical processes during the course of the H ii region evolution. We have also analyzed the transfer and deposit of the stellar wind and radiation energy into the circumstellar medium until the star explodes as a supernova. Although the total mechanical wind energy supplied by the star is negligible compared to the accumulated energy of the Lyman continuum photons, the kinetic energy imparted to the circumstellar gas over the star's lifetime is 4 times higher than for a comparable windless simulation. Furthermore, the thermal energy of warm photoionized gas is lower by some 55%. Our results document the necessity to consider both ionizing radiation and stellar winds for an appropriate description of the interaction of OB stars with their circumstellar environment. C1 Univ Kiel, Inst Theoret Phys & Astrophys, D-24098 Kiel, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Freyer, T (reprint author), Univ Kiel, Inst Theoret Phys & Astrophys, Olshaussenstr 40, D-24098 Kiel, Germany. NR 76 TC 101 Z9 102 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2003 VL 594 IS 2 BP 888 EP 910 DI 10.1086/376937 PN 1 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 720JL UT WOS:000185257600018 ER PT J AU Hubeny, I Burrows, A Sudarsky, D AF Hubeny, I Burrows, A Sudarsky, D TI A possible bifurcation in atmospheres of strongly irradiated stars and planets SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : general; planetary systems; planets and satellites : general; radiative transfer; stars : atmospheres; stars : low-mass, brown dwarfs ID COLLISION-INDUCED ABSORPTION; STELLAR ATMOSPHERES; INFRARED-ABSORPTION; MODEL ATMOSPHERES; GIANT PLANETS; BROWN DWARFS; H-2 PAIRS; TEMPERATURES; SPECTRA; LINES AB We show that under certain circumstances the differences between the absorption mean and Planck mean opacities can lead to multiple solutions for an LTE atmospheric structure. Since the absorption and Planck mean opacities are not expected to differ significantly in the usual case of radiative equilibrium, nonirradiated atmospheres, the most interesting situations in which the effect may play a role are strongly irradiated stars and planets, and also possibly structures in which there is a significant deposition of mechanical energy, such as stellar chromospheres and accretion disks. We have presented an illustrative example of a strongly irradiated giant planet in which the bifurcation effect is predicted to occur for a certain range of distances from the star. C1 Natl Opt Astron Observ, Tucson, AZ 85726 USA. NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Arizona, Dept Astron, Tucson, AZ 85721 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RP Hubeny, I (reprint author), Natl Opt Astron Observ, POB 26732,950 N Cherry, Tucson, AZ 85726 USA. NR 35 TC 180 Z9 181 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2003 VL 594 IS 2 BP 1011 EP 1018 DI 10.1086/377080 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 720JL UT WOS:000185257600029 ER PT J AU Fixsen, DJ AF Fixsen, DJ TI The spectrum of the cosmic microwave background anisotropy from the combined COBE FIRAS and WMAP observations SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : observations ID INSTRUMENT AB The cosmic microwave background (CMB) anisotropy data from the COBE Far Infrared Absolute Spectrophotometer (FIRAS) is reanalyzed in light of the Wilkinson Microwave Anisotropy Probe (WMAP) observations. The frequency spectrum of the FIRAS signal that has the spatial distribution seen by WMAP is shown to be consistent with CMB temperature fluctuations well into the Wien region of the spectrum. The consistency of these data, from very different instruments with very different observing strategies, provides compelling support for the interpretation that the signal seen by WMAP is temperature anisotropy of cosmological origin. The data also limit rms fluctuations in the Compton y parameter, observable via the Sunyaev-Zeldovich effect, to Deltay < 3 x 10(-6) (95% confidence level) on &SIM;5&DEG; angular scales. C1 NASA, Goddard Space Flight Ctr, SSAI, Greenbelt, MD 20771 USA. RP Fixsen, DJ (reprint author), NASA, Goddard Space Flight Ctr, SSAI, Code 685, Greenbelt, MD 20771 USA. NR 15 TC 11 Z9 11 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2003 VL 594 IS 2 BP L67 EP L70 DI 10.1086/378667 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 720JM UT WOS:000185257700001 ER PT J AU Ness, JU Starrfield, S Burwitz, V Wichmann, R Hauschildt, P Drake, JJ Wagner, RM Bond, HE Krautter, J Orio, M Hernanz, M Gehrz, RD Woodward, CE Butt, Y Mukai, K Balman, S Truran, JW AF Ness, JU Starrfield, S Burwitz, V Wichmann, R Hauschildt, P Drake, JJ Wagner, RM Bond, HE Krautter, J Orio, M Hernanz, M Gehrz, RD Woodward, CE Butt, Y Mukai, K Balman, S Truran, JW TI A Chandra low energy transmission grating spectrometer observation of V4743 Sagittarii: A supersoft X-ray source and a violently variable light curve SO ASTROPHYSICAL JOURNAL LA English DT Article DE novae, cataclysmic variables; stars : individual (V4743 Sagittarii); stars : oscillations; white dwarfs; X-rays : binaries ID NOVAE; DISCOVERY; EMISSION; ROSAT AB V4743 Sagittarii ( Nova Sgr 2002 No. 3) was discovered on 2002 September 20. We obtained a 5 ks ACIS-S spectrum in 2002 November and found that the nova was faint in X-rays. We then obtained a 25 ks Chandra Low Energy Transmission Grating Spectrometer (LETGS) observation on 2003 March 19. By this time, it had evolved into the supersoft X-ray phase exhibiting a continuous spectrum with deep absorption features. The light curve from the observation showed large-amplitude oscillations with a period of 1325 s ( 22 minutes) followed by a decline in the total count rate after similar to13 ks of observations. The count rate dropped from similar to 40 counts s(-1) to practically zero within similar to 6 ks and stayed low for the rest of the observation (similar to 6 ks). The spectral hardness ratio changed from maxima to minima in correlation with the oscillations and then became significantly softer during the decay. Strong H-like and He-like lines of oxygen, nitrogen, and carbon were found in absorption during the bright phase, indicating temperatures between 1 and 2 MK, but they were shifted in wavelength corresponding to a Doppler velocity of - 2400 km s(-1). The spectrum obtained after the decline in count rate showed emission lines of C vi, N vi, and N VII, suggesting that we were seeing expanding gas ejected during the outburst, probably originating from CNO-cycled material. An XMM-Newton Target of Opportunity observation, obtained on 2002 April 4 and a later LETGS observation from 2003 July 18 also showed oscillations, but with smaller amplitudes. C1 Hamburger Sternwarte, D-21029 Hamburg, Germany. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Max Planck Inst Extraterr Phys, D-85741 Garching, Germany. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Large Binocular Telescope Observ, Tucson, AZ 85721 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Heidelberg Konigstuhl Landessternwarte, D-69117 Heidelberg, Germany. INAF Turin Observ, I-10025 Pino Torinese, Italy. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. CSIC, Inst Ciencias Espacio, E-08034 Barcelona, Spain. Inst Estudis Espacials Catalunya, E-08034 Barcelona, Spain. Univ Minnesota, Dept Astron, Minneapolis, MN 55455 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Middle E Tech Univ, Dept Phys, TR-06531 Ankara, Turkey. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Ness, JU (reprint author), Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg, Germany. RI Hernanz, Margarita/K-1770-2014 OI Hernanz, Margarita/0000-0002-8651-7910 NR 16 TC 75 Z9 75 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2003 VL 594 IS 2 BP L127 EP L130 DI 10.1086/378664 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 720JM UT WOS:000185257700016 ER PT J AU Nyquist, LE Reese, Y Wiesmann, H Shih, CY Takeda, H AF Nyquist, LE Reese, Y Wiesmann, H Shih, CY Takeda, H TI Fossil Al-26 and Mn-53 in the Asuka 881394 eucrite: evidence of the earliest crust on asteroid 4 Vesta SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE eucrites; chronology; Al-26 heating; Al-16 timescale; Mn-53 timescale ID EARLY SOLAR-SYSTEM; ISOTOPIC ABUNDANCE RATIOS; ANGRA-DOS-REIS; ATOMIC WEIGHT; PIPLIA-KALAN; PARENT BODY; PLANETESIMALS; CHONDRULES; CHROMIUM; MODEL AB Asuka 881394 is a unique magnesian eucrite with pyroxenes that are Mg-rich like those of cumulate eucrites, but with a granulitic texture unlike the textures of cumulate eucrites. Plagioclase compositions are similar toAn(98), and are even more calcic than those in cumulate eucrites. Pyroxene does not show pigeonite-to-orthopyroxene inversion textures, suggesting different crystallization conditions than those of cumulate eucrites. Mn-Cr isotopic analyses determined initial Mn-53/Mn-55 = (4.6 +/- 1.7) x 10(-6) and initial epsilon(Cr-53)(1) = 0.25 +/- 0.17 in A881394. This initial Mn-53 abundance corresponds to a formation interval Deltat(LEW) = -6 +/- 2 Ma relative to the LEW86010 angrite, implying an 'absolute' age of 4564 +/- 2 Ma. Both the initial Mn-53 abundance and the initial epsilon(Cr-53), value for A881394 are identical to those previously determined for the HED parent body at the time of its differentiation. Al-Mg isotopic analyses determined initial Al-26/Al-27 = (1.18 +/- 0.14) x 10(-6), from which a formation interval Deltat(CAI) = 3.95 +/- 0.13 Ma is calculated relative to the canonical value Al-26/Al-27 = 5 x 10(-5) for CAI. Combining this formation interval with a recently reported Pb-Pb age of 4567.2 +/- 0.6 Ma for CAI gives 4563.2 +/- 0.6 Ma as the age of A881394, in excellent agreement with the age based on the Mn-Cr formation interval. Alternatively, the Mn-53 and Al-26 formation intervals of A881394 allow the Mn-Cr and Al-Mg timescales to be intercalibrated, suggesting that an 'absolute' CAI age of 4568 Ma is most consistent with the 4558 Ma Pb-Pb age of LEW86010. The initial Al-26 abundance existing in A881394 would have been insufficient to cause global melting in the HED parent body (probably asteroid 4 Vesta). Nevertheless, it could have been derived by radioactive decay over only similar to2 Ma from an abundance that would have been sufficient to cause global melting. The higher value of molar Mg/(Mg+Fe) = 0.57 for A881394 than those of the ordinary (basaltic) eucrites (Mg/(Mg+Fe) = 0.30-0.42) suggests additional factors may have been important for magma genesis on the parent body. If Al-26 were the only heat source, partial melting would have been the major process in the interior of the parent body, and Mg/(Mg+Fe) would be lower in the melts than in the primordial source material. Late-stage accretion could have supplied relatively magnesian primordial material to the surface of the parent body, thereby increasing Mg/(Mg+Fe) in a shallow magma ocean from which A881394 crystallized, and also may have augmented Al-26 heating. The granulitic texture of A881394 may have been produced during residence in the thin, earliest, crust, kept hot by the magma beneath it. If Al-26 was, nevertheless, the major heat source for asteroidal melting, it may account for declining post-accretion heating of main belt asteroids with increasing heliocentric distance. (C) 2003 Elsevier B.V. All rights reserved. C1 NASA, Lyndon B Johnson Space Ctr, SR, Houston, TX 77058 USA. Lockheed Martin Space Mission Syst & Serv Co, MC 23, Houston, TX 77058 USA. Chiba Inst Technol, Inst Res, Narashino, Chiba 2750016, Japan. RP Nyquist, LE (reprint author), NASA, Lyndon B Johnson Space Ctr, SR, 2101 NASA Rd 1, Houston, TX 77058 USA. NR 52 TC 44 Z9 45 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD SEP 10 PY 2003 VL 214 IS 1-2 BP 11 EP 25 DI 10.1016/S0012-821X(03)00371-6 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 721PU UT WOS:000185325400002 ER PT J AU Giglio, L Justice, CO AF Giglio, L Justice, CO TI Effect of wavelength selection on characterization of fire size and temperature SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article ID EOS-MODIS; IDENTIFICATION AB Over the past two decades, Dozier's 1981 retrieval method has been used with observations from various moderate-resolution (similar to1 km) spaceborne sensors to estimate the instantaneous sub-pixel area and temperature of wildfires. The method requires simultaneous observations at two different wavelengths. Traditionally these wavelengths have resided in the middle- and long-wave infrared regions, for example the 4 and 11 mum channels of the NOAA Advanced Very High Resolution Radiometer (AVHRR). Development of recent and upcoming sensors, including the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Visible/Infrared Imager/Radiometer Suite (VIIRS), have spawned interest in using other wavelength combinations, particularly in the short-wave infrared, for sub-pixel active fire characterization. We demonstrate that for realistic wildfires, which are composed of both flaming and smouldering components, the location of these two wavelengths can cause large differences in the fire temperatures and areas that are retrieved using Dozier's method. In the worst case considered, differences of 250 K in temperature and 80% in area were observed. C1 NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. Univ Maryland, Dept Geog, College Pk, MD 20742 USA. RP Giglio, L (reprint author), NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Code 923, Greenbelt, MD 20771 USA. NR 9 TC 42 Z9 42 U1 1 U2 8 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD SEP 10 PY 2003 VL 24 IS 17 BP 3515 EP 3520 DI 10.1080/0143116031000117056 PG 6 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA 701TA UT WOS:000184184000012 ER PT J AU Blake, NJ Blake, DR Simpson, IJ Meinardi, S Swanson, AL Lopez, JP Katzenstein, AS Barletta, B Shirai, T Atlas, E Sachse, G Avery, M Vay, S Fuelberg, HE Kiley, CM Kita, K Rowland, FS AF Blake, NJ Blake, DR Simpson, IJ Meinardi, S Swanson, AL Lopez, JP Katzenstein, AS Barletta, B Shirai, T Atlas, E Sachse, G Avery, M Vay, S Fuelberg, HE Kiley, CM Kita, K Rowland, FS TI NMHCs and halocarbons in Asian continental outflow during the Transport and Chemical Evolution over the Pacific (TRACE-P) Field Campaign: Comparison with PEM-West B SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE NMHCs; halocarbons; methyl bromide; methyl chloride; Halon-1211 ID INTERCOMPARISON EXPERIMENT NOMHICE; PAST 2 DECADES; NONMETHANE HYDROCARBONS; ALKYL NITRATES; FEBRUARY-MARCH; METHYL HALIDES; PHASE B; TRENDS; DISTRIBUTIONS; TROPOSPHERE AB [1] We present an overview of the spatial distributions of nonmethane hydrocarbons ( NMHCs) and halocarbons observed over the western north Pacific as part of the NASA GTE Transport and Chemical Evolution over the Pacific (TRACE-P) airborne field campaign ( February-April 2001). The TRACE-P data are compared with earlier measurements from the Pacific Rim during the Pacific Exploratory Mission-West B ( PEM-West B), which took place in February-March 1994, and with emission inventory data for 2000. Despite the limited spatial and temporal data coverage inherent to airborne sampling, mean levels of the longer-lived NMHCs ( including ethane, ethyne, and benzene) were remarkably similar to our results during the PEM-West B campaign. By comparison, mixing ratios of the fire extinguisher Halon-1211 (CF2ClBr) increased by about 50% in the period between 1994 and 2001. Southern China ( south of 35degreesN), and particularly the Shanghai region, appears to have been a substantial source of Halon-1211 during TRACE-P. Our previous analysis of the PEM-West B data employed methyl chloroform ( CH3CCl3) as a useful industrial tracer. However, regulations have reduced its emissions to the extent that its mixing ratio during TRACE-P was only one-third of that measured in 1994. Methyl chloroform mixing ratio "hot spots,'' indicating regions downwind of continuing emissions, included outflow from the vicinity of Shanghai, China, but particularly high emission ratios relative to CO were observed close to Japan and Korea. Tetrachloroethene ( C2Cl4) levels have also decreased significantly, especially north of 25degreesN, but this gas still remains a useful indicator of northern industrial emissions. Methyl bromide ( CH3Br) levels were systematically 1-2 pptv lower from 1994 to 2001, in accord with recent reports. However, air masses that had been advected over Japan and/or South Korean port cities typically exhibited elevated levels of CH3Br. As a consequence, emissions of CH3Br from Japan and Korea calculated employing CH3Br/CO ratios and scaled to CO emission inventory estimates, were almost as large as for all of south China ( south of 35degreesN). Total east Asian emissions of CH3Br and CH3Cl were estimated to be roughly 4.7 Gg/yr and 167 Gg/yr, respectively, in 2001. C1 Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. Natl Space Dev Agcy Japan, Earth Observat Res Ctr, Chuo Ku, Tokyo 1040023, Japan. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80305 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Ibaraki Univ, Fac Sci, Dept Environm Sci, Ibaraki 3108512, Japan. RP Blake, NJ (reprint author), Univ Calif Irvine, Dept Chem, 516 Rowland Hall, Irvine, CA 92697 USA. EM nblake@uci.edu; drblake@uci.edu; isimpson@uci.edu; smeinard@uci.edu; aswanson@ucar.edu; jlopez@mail.arc.nasa.gov; akatzens@uci.edu; bbarlett@uci.edu; shirai@eorc.nasda.go.jp; atlas@ucar.edu; g.w.sachse@larc.nasa.gov; m.a.avery@larc.nasa.gov; s.a.vay@larc.nasa.gov; fuelberg@huey.met.fsu.edu; ckiley@huey.met.fsu.edu; kita@mx.ibaraki.ac.jp; rowland@uci.edu RI Atlas, Elliot/J-8171-2015 NR 67 TC 114 Z9 116 U1 3 U2 20 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 10 PY 2003 VL 108 IS D20 AR 8806 DI 10.1029/2002JD003367 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 775AA UT WOS:000189017500002 ER PT J AU Peterson, WT Schwing, FB AF Peterson, WT Schwing, FB TI A new climate regime in northeast pacific ecosystems SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CALIFORNIA CURRENT; EL-NINO; OCEAN; ZOOPLANKTON; SHIFTS; EVOLUTION; SARDINES; EVENTS AB Following a strong El Nino, the climate of the North Pacific underwent a rapid and striking transition in late 1998. Upwelling-favorable winds strengthened over the California Current (CC), and winds weakened in the Gulf of Alaska (GOA). Coastal waters of the CC and GOA cooled by several degrees, and the Pacific Decadal Oscillation (PDO) reversed sign and remained negative through summer 2002. Zooplankton biomass in the northern CC doubled and switched from warm to cold water species dominance, coho and chinook salmon stocks rebounded, and anchovy and osmeriids increased. Persistent changes in atmosphere and upper ocean fields and ecosystem structure suggest a climate regime shift has occurred, similar (opposite) to shifts observed in 1947 (1925 and 1976). If the 1998 regime shift in the northern CC is completely analogous to earlier shifts, then ecosystem structure should have changed in the GOA. Recent surveys indicate this ecosystem has transformed as well. C1 Oregon State Univ, Hatfield Marine Sci Ctr, NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Newport, OR 97365 USA. SW Fisheries Sci Ctr, Natl Marine Fisheries Serv, Pacific Grove, CA 93950 USA. RP Peterson, WT (reprint author), Oregon State Univ, Hatfield Marine Sci Ctr, NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, 2030 S Marine Sci Dr, Newport, OR 97365 USA. EM bill.peterson@noaa.gov; fschwing@pfeg.noaa.gov NR 31 TC 285 Z9 292 U1 1 U2 68 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD SEP 9 PY 2003 VL 30 IS 17 AR 1896 DI 10.1029/2003GL017528 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 774ZJ UT WOS:000189016000002 ER PT J AU Eisele, FL Mauldin, L Cantrell, C Zondlo, M Apel, E Fried, A Walega, J Shetter, R Lefer, B Flocke, F Weinheimer, A Avery, M Vay, S Sachse, G Podolske, J Diskin, G Barrick, JD Singh, HB Brune, W Harder, H Martinez, M Bandy, A Thornton, D Heikes, B Kondo, Y Riemer, D Sandholm, S Tan, D Talbot, R Dibb, J AF Eisele, FL Mauldin, L Cantrell, C Zondlo, M Apel, E Fried, A Walega, J Shetter, R Lefer, B Flocke, F Weinheimer, A Avery, M Vay, S Sachse, G Podolske, J Diskin, G Barrick, JD Singh, HB Brune, W Harder, H Martinez, M Bandy, A Thornton, D Heikes, B Kondo, Y Riemer, D Sandholm, S Tan, D Talbot, R Dibb, J TI Summary of measurement intercomparisons during TRACE-P SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aircraft measurement intercomparison; chemistry instruments ID AIRBORNE INSTRUMENT INTERCOMPARISONS; PEM-TROPICS-B; CARBON-MONOXIDE; CENTRAL PACIFIC; SULFUR-DIOXIDE; TROPOSPHERE; FATE AB [1] The NASA DC-8 and P-3B aircraft flew within about a kilometer or less of each other on three occasions during the Transport and Chemical Evolution Over the Pacific (TRACE-P) campaign in order to intercompare similar measurements on the two aircraft. The first and last intercomparisons were in relatively remote marine environments during transits to and from Asia. The first began with a boundary layer measurement followed by an ascent to 3 km. The second set of intercomparisons was at a fixed altitude of about 5.2 km off the coast of Japan, also in relatively clean air. Finally, the third measurement began at 5.3 km and then descended into the boundary layer. A number of measurements were compared with the best agreement observed for the most abundant compounds such as CO2 and CH4 and with very good agreement for CO, O-3, and j values. Other comparisons, including measurements of the same compounds on both aircraft and measurements of the same compound by two different instruments on the DC-8, varied over a wide range from quite good for PAN, NO, HNO3, H2O; to reasonable agreement for OH, HO2 CH2O, acetone, and methylethylketone; and to generally poor for NO2, SO2, PPN, acetaldehyde, and methanol. The comparison results, particularly those for the fast 1-s CO and O-3 measurements, suggest that credible intercomparisons can be made using two aircraft in close proximity for relatively long lifetime and stable compounds. Much new understanding can also be gained from measurements of more reactive and generally shorter lifetime compounds, but additional improvements are needed to make such studies as meaningful as those of longer lifetime compounds. Comparisons such as these, made as a component of a larger field campaign, have the advantage that they test the actual instrument configuration used during the field study and they require no additional instrument installation and testing. C1 Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80303 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA. Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, Tokyo 1538904, Japan. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. Univ New Hampshire, Climate Change Res Ctr, Durham, NH 03824 USA. RP Eisele, FL (reprint author), Natl Ctr Atmospher Res, Div Atmospher Chem, 1850 Table Mesa Dr, Boulder, CO 80303 USA. EM eisele@ucar.edu; cantrell@ucar.edu; apel@ucar.edu; walega@ucar.edu; shetter@ucar.edu; ffl@acd.ucar.edu; s.a.vay@larc.nasa.gov; podolske@nasa.gov; j.d.barrick@larc.nasa.gov; hsingh@mail.arc.nasa.gov; brune@ems.psu.edu; alan.bandy@drexel.edu; kondo@atmos.rcast.u-tokyo.ac.jp; d.riemer@miami.edu; ss27@prism.gatech.edu; dtan@eas.gatech.edu; robert.talbot@unh.edu RI Kondo, Yutaka/D-1459-2012; Harder, Hartwig/L-2511-2014; Lefer, Barry/B-5417-2012; Zondlo, Mark/R-6173-2016 OI Harder, Hartwig/0000-0002-6868-714X; Lefer, Barry/0000-0001-9520-5495; Zondlo, Mark/0000-0003-2302-9554 NR 32 TC 40 Z9 40 U1 0 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 SEP 9 PY 2003 VL 108 IS D20 AR 8791 DI 10.1029/2002JD003167 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 774ZZ UT WOS:000189017400001 ER PT J AU Okojie, RS Holzheu, T Huang, XR Dudley, M AF Okojie, RS Holzheu, T Huang, XR Dudley, M TI X-ray diffraction measurement of doping induced lattice mismatch in n-type 4H-SiC epilayers grown on p-type substrates SO APPLIED PHYSICS LETTERS LA English DT Article ID SIC EPITAXIAL LAYERS AB High-resolution x-ray diffractometry was used to measure the lattice mismatch and misorientation in n-type 4H-SiC epilayers grown homoepitaxially on p-type 4H-SiC as function of different nitrogen doping levels. The spatially averaged lattice mismatch increased from 1.0x10(-5) to 4.0x10(-5), 6.3x10(-5), 8.8x10(-5), and 11.6x10(-5) in epilayers doped 4.1x10(17) cm(-3), 2.6x10(18) cm(-3), 1.7x10(19) cm(-3), 2.2x10(19), and 4x10(19), respectively. The resolved multiple subsidiary peaks in the rocking curve of the epilayers doped 2.2x10(19) and 4x10(19) cm(-3) are likely due to high density of domain boundaries. The increase in mismatch with doping, is attributed to the substitutional nitrogen incorporated preferentially in the host carbon sites of the 4H-SiC epilayer. (C) 2003 American Institute of Physics. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. CAMET Res Inc, Goleta, CA 93117 USA. SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. RP Okojie, RS (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,M-S 77-1, Cleveland, OH 44135 USA. NR 5 TC 20 Z9 22 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 SEP 8 PY 2003 VL 83 IS 10 BP 1971 EP 1973 DI 10.1063/1.1606497 PG 3 WC Physics, Applied SC Physics GA 717LJ UT WOS:000185089800022 ER PT J AU Leon, JF Tanre, D Pelon, J Kaufman, YJ Haywood, JM Chatenet, B AF Leon, JF Tanre, D Pelon, J Kaufman, YJ Haywood, JM Chatenet, B TI Profiling of a Saharan dust outbreak based on a synergy between active and passive remote sensing SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosols; lidar; Saharan dust ID AEROSOL OPTICAL-PROPERTIES; MICROPHYSICAL PARTICLE PARAMETERS; BACKSCATTER LIDAR DATA; IMAGING SPECTRORADIOMETER; TROPOSPHERIC AEROSOL; RADIATIVE PROPERTIES; SPECTRAL RADIANCES; INVERSION; OCEAN; EXTINCTION AB [1] Spaceborne lidars will give a new view of the vertical distribution of atmospheric aerosols and clouds. CALIPSO will be launched in the fall of 2004 and will provide, for the first time, a global picture of the profile of atmospheric scattering layers using an onboard lidar radiated at 0.532 and 1.064 mum. CALIPSO will fly in an orbital formation with passive radiometers, such as the Moderate resolution Imaging Spectrometer ( MODIS) and the Polarization and Directionality of Earth's Reflectance ( POLDER) instruments, that monitor Earth's atmosphere. The purpose of this paper is to analyze the improvement in retrieval capabilities of profiles of aerosol optical properties using a synergy between passive and active ( lidar) remote sensing techniques. Aerosol properties derived from the MODIS spectroradiometer are used to constrain the inversion of the lidar signal in terms of aerosol optical thickness and effective radius. We use the lidar spectral backscattering coefficient between 0.532 and 1.064 mm to determine the profile of backscatter-to-extinction ratio. The effective radius of an assumed bimodal aerosol size distribution is then retrieved as a function of the altitude. A sensitivity analysis demonstrates the robustness of the inversion procedure in case of noise detection and calibration error. The algorithm has been tested during the Saharan dust experiment, which took place in the northeastern tropical Atlantic in September 2000. The vertical profile of extinction compares well with in situ measurements of the aerosol extinction. Profiles derived from lidar measurements on 25 September highlight the presence of the Saharan air layer located between 2.2 and 4.5 km with particle effective radii of 1.19 +/- 0.6 mm. Another dust layer within the sub-Saharan transition layer over the marine boundary layer is also observed, with particle radii significantly smaller than within the Saharan air layer. C1 Univ Lille 1, Opt Atmospher Lab, CNRS, F-59655 Villeneuve Dascq, France. Univ Paris 06, CNRS, Inst Pierre Simon Laplace, Serv Aeron, F-75252 Paris, France. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Paris 12, CNRS, Lab Interuniv Syst Atmospher, Paris, France. RP Leon, JF (reprint author), Univ Lille 1, Opt Atmospher Lab, CNRS, F-59655 Villeneuve Dascq, France. EM leon@loa.univ-lille1.fr; tanre@loa.univ-lille1.fr; jacques.pelon@aero.jussieu.fr; kaufman@climate.gsfc.nasa.gov; jmhaywood@metoffice.com; chatenet@lisa.univ-paris12.fr NR 41 TC 39 Z9 39 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 8 PY 2003 VL 108 IS D18 AR 8575 DI 10.1029/2002JD002774 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 774ZX UT WOS:000189017200001 ER PT J AU Huang, NE Wu, MLC Long, SR Shen, SSP Qu, WD Gloersen, P Fan, KL AF Huang, NE Wu, MLC Long, SR Shen, SSP Qu, WD Gloersen, P Fan, KL TI A confidence limit for the empirical mode decomposition and Hilbert spectral analysis SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article DE empirical mode decomposition; EMD/HSA; Hilbert spectral analysis; Hilbert-Huang transform (HHT); nonlinear data analysis; non-steady data analysis ID EARTH-ORIENTATION MEASUREMENTS; INDICIAL RESPONSE; STEP HYPOXIA; COMBINATIONS; OSCILLATION; SERIES; WAVE AB The confidence limit is a standard measure of the accuracy of the result in any statistical analysis. Most of the confidence limits are derived as follows. The data are first divided into subsections and then, under the ergodic assumption, the temporal mean is substituted for the ensemble mean. Next, the confidence limit is defined as a range of standard deviations from this mean. However, such a confidence limit is valid only for linear and stationary processes. Furthermore, in order for the ergodic assumption to be valid, the subsections have to be statistically independent. For non-stationary and nonlinear processes, such an analysis is no longer valid. The confidence limit of the method here termed EMD/HSA (for empirical mode decomposition/Hilbert spectral analysis) is introduced by using various adjustable stopping criteria in the sifting processes of the EMD step to generate a sample set of intrinsic mode functions (IMFs). The EMD technique acts as a pre-processor for HSA on the original data, producing a set of components (IMFs) from the original data that equal the original data when added back together. Each IMF represents a scale in the data, from smallest to largest. The ensemble mean and standard deviation of the IMF sample sets obtained with different stopping criteria are calculated, and these form a simple random sample set. The confidence limit for EMD/HSA is then defined as a range of standard deviations from the ensemble mean. Without evoking the ergodic assumption, subdivision of the data stream into short sections is unnecessary; hence, the results and the confidence limit retain the full-frequency resolution of the full dataset. This new confidence limit can be applied to the analysis of nonlinear and non-stationary processes by these new techniques. Data from length-of-day measurements and a particularly violent recent earthquake are used to demonstrate how the confidence limit is obtained and applied. By providing a confidence limit for this new approach, a stable range of stopping criteria for the decomposition or sifting phase (EMD) has been established, making the results of the final processing with HSA, and the entire EMD/HSA method, more definitive. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. Univ Alberta, Dept Math Sci, Edmonton, AB T6G 2G1, Canada. CALTECH, Pasadena, CA 91125 USA. Natl Taiwan Univ, Inst Oceanog, Taipei 106, Taiwan. RP Huang, NE (reprint author), NASA, Goddard Space Flight Ctr, Code 971, Greenbelt, MD 20771 USA. EM norden.e.huang@nasa.gov RI Long, Steven/D-7248-2012 NR 22 TC 533 Z9 665 U1 11 U2 91 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-5021 EI 1471-2946 J9 P ROY SOC A-MATH PHY JI Proc. R. Soc. A-Math. Phys. Eng. Sci. PD SEP 8 PY 2003 VL 459 IS 2037 BP 2317 EP 2345 DI 10.1098/rspa.2003.1123 PG 29 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 720VU UT WOS:000185281200010 ER PT J AU Astone, P Babusci, D Bassan, M Borkowski, KM Coccia, E D'Antonio, S Fafone, V Giordano, G Jaranowski, P Krolak, A Marini, A Minenkov, Y Modena, I Modestino, G Moleti, A Pallottino, GV Pietka, M Pizzella, G Quintieri, L Rocchi, A Ronga, F Terenzi, R Visco, M AF Astone, P Babusci, D Bassan, M Borkowski, KM Coccia, E D'Antonio, S Fafone, V Giordano, G Jaranowski, P Krolak, A Marini, A Minenkov, Y Modena, I Modestino, G Moleti, A Pallottino, GV Pietka, M Pizzella, G Quintieri, L Rocchi, A Ronga, F Terenzi, R Visco, M TI All-sky upper limit for gravitational radiation from spinning neutron stars SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article; Proceedings Paper CT 7th Gravitational Wave Data Analysis Workshop (GWDAW2002) CY DEC 17-19, 2002 CL INT INST ADV STUDIES, KYOTO, JAPAN HO INT INST ADV STUDIES AB We present results of the all-sky search for gravitational-wave signals from spinning neutron stars in the data of the EXPLORER resonant bar detector. Our data analysis technique was based on the maximum likelihood detection method. We briefly describe the theoretical methods that we used in our search. The main result of our analysis is an upper limit of 2 x 10(-23) for the dimensionless amplitude of the continuous gravitational-wave signals coming from any direction in the sky and in the narrow frequency band from 921.00 Hz to 921.76 Hz. C1 Ist Nazl Fis Nucl, Rome, Italy. Ist Nazl Fis Nucl, Frascati, Italy. Univ Roma Tor Vergata, Rome, Italy. Nicholas Copernicus Univ, Ctr Astron, Torun, Poland. Univ Bialystok, Inst Theoret Phys, Bialystok, Poland. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. CNR, IFSI, Rome, Italy. RP Astone, P (reprint author), Ist Nazl Fis Nucl, Rome, Italy. RI Bassan, Massimo/J-1652-2012; Borkowski, Kazimierz/E-6716-2014; Rocchi, Alessio/O-9499-2015; Moleti, Arturo/P-6812-2016 OI Rocchi, Alessio/0000-0002-1382-9016; Moleti, Arturo/0000-0002-2465-8849 NR 7 TC 15 Z9 15 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD SEP 7 PY 2003 VL 20 IS 17 SI SI BP S665 EP S676 AR PII S0264-9381(03)62484-6 DI 10.1088/0264-9381/20/17/310 PG 12 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 725RV UT WOS:000185556900011 ER PT J AU Fuelberg, HE Kiley, CM Hannan, JR Westberg, DJ Avery, MA Newell, RE AF Fuelberg, HE Kiley, CM Hannan, JR Westberg, DJ Avery, MA Newell, RE TI Meteorological conditions and transport pathways during the Transport and Chemical Evolution over the Pacific (TRACE-P) experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE TRACE-P meteorology; atmospheric transport; Asian outflow; trajectories ID EXPLORATORY MISSION-WEST; PEM-TROPICS-B; MARCH-APRIL 1999; SOUTHERN OSCILLATION; NORTH PACIFIC; EAST-ASIA; PHASE B; CLIMATOLOGY; TRAJECTORIES; TROPOSPHERE AB [1] The Transport and Chemical Evolution over the Pacific (TRACE-P) experiment was conducted between February and April 2001. It included extensive chemical sampling by two aircraft based primarily in Hong Kong and Yokota Air Base, Japan. TRACE-P examined pathways for the outflow of chemically and radiatively important gases and aerosols and their precursors from eastern Asia to the western Pacific and explored the chemical evolution of Asian outflow. This paper describes meteorological conditions and transport pathways over the Pacific Basin during TRACE-P. Meteorological conditions changed rapidly during the period due to the seasonal winter to spring transition and the decay of prolonged ENSO cold phase (La Nina) conditions. To document these changes, TRACE-P was divided into two halves, and mean flow patterns during each half are presented and discussed. Important circulation features are the semipermanent Siberian anticyclone and transient middle latitude cyclones that form near eastern Asia and then move eastward over the northern Pacific. Five-day backward trajectories from the various flight tracks show that air sampled by the aircraft had been transported from a variety of locations. Some parcels remained over the tropical western North Pacific during the entire period, while other important origins were Southeast Asia, Africa, and central Asia. Specifically, lower tropospheric flight segments out of Hong Kong sampled both prefrontal maritime air as well as postfrontal air from the Asian continent. Conversely, low-level flight segments out of Yokota, Japan mostly sampled postfrontal Asian air. Southern portions of middle and upper tropospheric flight segments from Hong Kong sampled air previously in the deep tropics, while the more northerly flight segments sampled air that originated from the west ( e. g., passing over central Africa and India). Most upper level flight segments from Yokota sampled air arriving from the west. Patterns of satellite-derived precipitation and lightning are described. TRACE-P occurs during a neutral to weak La Nina period of relatively cold sea surface temperatures in the tropical Pacific. Compared with climatology, the TRACE-P period exhibits deep convection located west of its typical position; however, tropospheric flow patterns do not exhibit a strong La Nina signal. Circulation patterns during TRACE-P are found to be generally similar to those during NASA's PEM WEST-B mission that occurred in the same region during February - March 1994. C1 Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. NASA, Langley Res Ctr, Hampton, VA USA. Sci Applicat Int Corp, Hampton, VA USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA USA. RP Fuelberg, HE (reprint author), Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. EM fuelberg@met.fsu.edu; ckiley@met.fsu.edu; hannan@met.fsu.edu; d.j.westberg@larc.nasa.gov; m.a.avery@larc.nasa.gov NR 46 TC 52 Z9 55 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 6 PY 2003 VL 108 IS D20 AR 8782 DI 10.1029/2002JD003092 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 722EJ UT WOS:000185362200001 ER PT J AU Sano, I Mukai, S Okada, Y Holben, BN Ohta, S Takamura, T AF Sano, I Mukai, S Okada, Y Holben, BN Ohta, S Takamura, T TI Optical properties of aerosols during APEX and ACE-Asia experiments SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosol optical thickness; Asian dust; AERONET; ACE-Asia; APEX ID SKY RADIANCE MEASUREMENTS; RETRIEVAL; SUN; ALGORITHM; AERONET; NETWORK; CLOUD AB [1] Sun/sky photometry and polarimetry of atmospheric light have been undertaken by multispectral photometers (CE- 318-1 and - 2, Cimel Electronique, France) and a polarimeter (PSR- 1000, Opto Research, Japan) over Amami, Noto, and Shirahama, Japan, during APEX-E1, - E2, and ACE-Asia field campaigns. Radiometers provide us with the optical thickness of aerosols and Angstrom exponent. Other aerosol characteristics, e. g., size distribution, refractive index, etc., are retrieved based on each inversion method corresponding each equipment. The former takes a standard AERONET processing, and the latter is according to our own procedure to analyze the polarimetry with PSR- 1000. After several aerosol parameters are derived, the HYSPLIT4 backward trajectory analysis is adopted to search the origin of aerosols. It is shown from these ground measurements that aerosol optical thickness, Angstrom exponent, and refractive index are classified into two typical categories as a background type detected in winter, and a soil dust type appeared in Asian dust events in spring. Further, it is found that the obtained size distribution of Asian dust indicates the dominance of large particles. C1 Kinki Univ, Fac Sci & Technol, Osaka 5778502, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Hokkaido Univ, Grad Sch Engn, Sapporo, Hokkaido 0600808, Japan. Chiba Univ, Ctr Environm Remote Sensing, Inage Ku, Chiba 2638522, Japan. RP Sano, I (reprint author), Kinki Univ, Fac Sci & Technol, Kowakae 3-4-1, Osaka 5778502, Japan. EM sano@info.kindai.ac.jp; mukai@info.kindai.ac.jp; yo372@io.im.kindai.ac.jp; brent@aeronet.gsfc.nasa.gov; ohta@eng.hokudai.ac.jp; takamura@cr.chiba-u.ac.jp NR 20 TC 30 Z9 30 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 6 PY 2003 VL 108 IS D23 AR 8649 DI 10.1029/2002JD003263 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 722EM UT WOS:000185362500001 ER PT J AU Birn, J Schindler, K Hesse, M AF Birn, J Schindler, K Hesse, M TI Formation of thin current sheets in the magnetotail: Effects of propagating boundary deformations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE current sheet formation; substorm growth phase; substorm trigger ID DRIFT-KINK INSTABILITY; NEAR-EARTH MAGNETOTAIL; SUBSTORM GROWTH-PHASE; CURRENT DISRUPTION; MAGNETOSPHERIC SUBSTORMS; MAGNETIC-FIELD; NEUTRAL SHEET; LINEAR-THEORY; MECHANISM; ONSET AB [1] Observations and simulations have demonstrated the important role of thin current sheet formation in the course of substorms. Previously, using two-dimensional magnetohydrostatic equilibrium theory together with magnetic flux, entropy, and topology conservation, we demonstrated that a finite boundary deformation of magnetotail equilibria can lead to a loss of equilibrium; that is, equilibrium configurations that satisfy the constraints cease to exist when the boundary deformation exceeds a critical value. When the critical threshold is approached, locally the current density becomes infinite; that is, a thin current sheet is formed. Using time-dependent MHD simulations, we confirm the basic theoretical results. We further extend this work to study the effects of tailward propagating boundary perturbations, corresponding to the rise and subsequent reduction of a duskward electric field (rise and subsequent northward turning of southward IMF B-z). We demonstrate that these boundary conditions again can lead to thin current sheet formation and the possible loss of equilibrium (catastrophe) or onset of instability. Finite perturbations of magnitudes consistent with those observed can produce a strong local increase of the current density and a local reduction of the magnetic field component B-z in the center of the plasma sheet, so that kinetic instabilities and a dynamic evolution may be triggered. The current sheet formation is influenced not only by the magnitude and the duration of the applied electric field but also by the temporal profile: A sudden decrease of the driving electric field following a more gradual increase is more effective than a gradual decrease following a sudden increase. This may provide a clue for the apparent substorm triggering by sudden northward turning of the IMF. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Ruhr Univ Bochum, Inst Theoret Phys 4, D-44780 Bochum, Germany. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Birn, J (reprint author), Los Alamos Natl Lab, MS D466, Los Alamos, NM 87545 USA. RI Hesse, Michael/D-2031-2012 NR 34 TC 14 Z9 15 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 SEP 6 PY 2003 VL 108 IS A9 AR 1337 DI 10.1029/2002JA009641 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 722FP UT WOS:000185365000001 ER PT J AU Mueller, CH Croke, ET Alterovitz, SA AF Mueller, CH Croke, ET Alterovitz, SA TI High electron mobility in SiGe/Si n-MODFET structures on sapphire substrates SO ELECTRONICS LETTERS LA English DT Article ID SILICON-ON-SAPPHIRE AB For the first time, SiGe/Si n-modulation doped field effect transistor (n-MODFET) structures have been grown on sapphire substrates. A room temperature electron mobility value of 1271 cm(2) /V-s at an electron carrier density (n(e)) of 1.6 x 10(12) cm(-2) was obtained. At 250 mK, the mobility increases to 13 313 cm(2)/V-s (n(e) = 1.33 x 10(12) cm(-2)) and Shubnikov-de Haas oscillations appear, showing excellent confinement of the two-dimensional electron gas. C1 Analex Corp, Cleveland, OH 44135 USA. HRL Labs, LLC, Malibu, CA USA. NASA, Glenn Res Ctr, Cleveland, OH USA. RP Mueller, CH (reprint author), Analex Corp, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 8 TC 6 Z9 6 U1 1 U2 2 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD SG1 2AY, ENGLAND SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD SEP 4 PY 2003 VL 39 IS 18 BP 1353 EP 1354 DI 10.1049/el:20030871 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA 724HX UT WOS:000185483100038 ER PT J AU Arola, A Kaurola, J Koskinen, L Tanskanen, A Tikkanen, T Taalas, P Herman, JR Krotkov, N Fioletov, V AF Arola, A Kaurola, J Koskinen, L Tanskanen, A Tikkanen, T Taalas, P Herman, JR Krotkov, N Fioletov, V TI A new approach to estimating the albedo for snow-covered surfaces in the satellite UV method SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ultraviolet radiation; snow albedo; satellite; estimates of UV irradiance; reflectivity ID SPECTRAL ALBEDO; IRRADIANCE; ULTRAVIOLET; RADIATION; CLOUDS AB [1] This paper describes a new method for estimating snow albedo for satellite retrieval of surface UV irradiance and daily UV doses over snow-covered terrains. The method is based on combining satellite and meteorological analysis data. The satellite data exploited in this work are the measured reflectivities of the Total Ozone Mapping Spectrometer/ Nimbus 7 instrument that coincides with the European Centre for Medium-Range Weather Forecasts ERA-15 reanalyzed meteorological data. We compared satellite-retrieved UV daily doses to the ground-based measurements of two Finnish and five Canadian sites. The comparison clearly showed that the new snow albedo approach improves the accuracy of the satellite-retrieved UV doses. C1 Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Meteorol Serv Canada, Toronto, ON M3H 5T4, Canada. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Arola, A (reprint author), Finnish Meteorol Inst, POB 503,Vuorikatu 19, FIN-00101 Helsinki, Finland. EM antti.arola@fmi.fi RI Krotkov, Nickolay/E-1541-2012 OI Krotkov, Nickolay/0000-0001-6170-6750 NR 16 TC 16 Z9 16 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 4 PY 2003 VL 108 IS D17 AR 4531 DI 10.1029/2003JD003492 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 722EB UT WOS:000185361500008 ER PT J AU Bernhard, G Booth, CR McPeters, RD AF Bernhard, G Booth, CR McPeters, RD TI Calculation of total column ozone from global UV spectra at high latitudes SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE total column ozone; ozone profile; ultraviolet radiation measurements ID NETWORK AB [1] A new algorithm to retrieve total column ozone from global spectral UV irradiance measurements is presented, and its accuracy is assessed. The expanded uncertainty ( coverage factor 2) of the resulting ozone values varies between 2% and 3.5% for solar zenith angles (SZA) smaller than 75degrees and clear skies. For larger SZA the uncertainty becomes dominated by the sensitivity of the method to the atmospheric ozone distribution. Using this algorithm, ozone values were calculated from UV spectra measured by the National Science Foundation's SUV-100 spectroradiometer at Barrow, Alaska, between 1996 and 2001. Special attention was given to March - April 2001, the period when the campaign "Total Ozone Measurements by Satellites, Sondes, and Spectrometers at Fairbanks'' ( TOMS 3 F) took place. The data set was compared with observations by NASA's Earth Probe Total Ozone Mapping Spectrometer ( TOMS) and a Dobson spectrophotometer operated by NOAA's Climate Monitoring and Diagnostics Laboratory ( CMDL) at Barrow. On average, the new algorithm generates ozone values in spring 2.2% lower than TOMS observations and 1.8% higher than Dobson measurements. From the uncertainty budget and the comparison with TOMS and Dobson it can be concluded that ozone values retrieved from global UV spectra have a similar accuracy as observations with standard instrumentation used for ozone monitoring. The new data set can therefore be used for validation of other ozone data. C1 Biospher Inc, San Diego, CA 92110 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Bernhard, G (reprint author), Biospher Inc, 5340 Riley St, San Diego, CA 92110 USA. EM bernhard@biospherical.com RI McPeters, Richard/G-4955-2013 OI McPeters, Richard/0000-0002-8926-8462 NR 8 TC 21 Z9 21 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 4 PY 2003 VL 108 IS D17 AR 4532 DI 10.1029/2003JD003450 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 722EB UT WOS:000185361500006 ER PT J AU Ginoux, P Torres, O AF Ginoux, P Torres, O TI Empirical TOMS index for dust aerosol: Applications to model validation and source characterization SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE dust sources; dust modeling; TOMS satellite ID SAHARAN DUST; ULTRAVIOLET-RADIATION; PARTICLE DEPOSITION; MINERAL AEROSOL; GLOBAL-MODEL; DESERT; OZONE; AIR; TROPOSPHERE; VARIABILITY AB [1] An empirical relation is developed to express the Total Ozone Mapping Spectrometer ( TOMS) aerosol index ( AI) for the case of dust plumes, as an explicit function of four physical quantities: the single scattering albedo, optical thickness, altitude of the plume and surface pressure. This relation allows sensitivity analysis of the TOMS AI with physical properties, quantitative comparison with dust model results and physical analysis of dust sources, without the necessity of cumbersome radiative calculation. Two applications are presented: ( 1) the case study of a dust storm over the North Atlantic in March 1988, and ( 2) the characterization of 13 major dust sources. The first application shows that simulated dust distribution can be quantitatively compared to TOMS AI on a daily basis and over regions where dust is the dominant aerosol. The second application necessitates to further parameterize the relation by replacing the optical thickness and the altitude of the plume by meteorological variables. The advantage is that surface meteorological fields are easily available globally and for decades but the formulation only applies to dust sources. The daily, seasonal and interannual variability of the parameterized index over major dust sources reproduces correctly the variability of the observed TOMS AI. The correlation between these two indices is used to determine the surface characteristics and physical properties of dust aerosol over the sources. C1 Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP NOAA, Geophys Fluid Dynam Lab, Forrestal Campus,POB 308, Princeton, NJ 08542 USA. EM paul.ginoux@noaa.gov; torres@tparty.gsfc.nasa.gov RI Ginoux, Paul/C-2326-2008; Torres, Omar/G-4929-2013 OI Ginoux, Paul/0000-0003-3642-2988; NR 43 TC 43 Z9 43 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 4 PY 2003 VL 108 IS D17 AR 4534 DI 10.1029/2003JD003470 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 722EB UT WOS:000185361500007 ER PT J AU Gostowski, R AF Gostowski, R TI Isothermal calorimetric observations of the effect of welding on compatibility of stainless steels with high-test hydrogen peroxide propellant SO THERMOCHIMICA ACTA LA English DT Article DE isothermal microcalorimetry; hydrogen peroxide; stainless steel; compatibility; welding AB Welding of stainless steels (CRES 316L and CRES 304L) was found to increase surface roughness and more importantly to decrease their compatibility with high-test hydrogen peroxide (HTP). Compatibility was determined by isothermal microcalorimeter (IMC) measurements. Omission of a purge gas enhances welding effects. Previous literature indicated welding causes segregation of chromium and iron in the heat affected zone (HAZ) and in the weld bead itself. It is likely that these surface modifications are responsible for the diminished compatibility, however a direct correlation was not established. (C) 2003 Elsevier Science B.V. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Gostowski, R (reprint author), NASA, George C Marshall Space Flight Ctr, TD40, Huntsville, AL 35812 USA. NR 6 TC 4 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-6031 J9 THERMOCHIM ACTA JI Thermochim. Acta PD SEP 4 PY 2003 VL 404 IS 1-2 BP 279 EP 281 DI 10.1016/S0040-6031(03)00121-7 PG 3 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA 723TU UT WOS:000185448300033 ER PT J AU Bozzolo, G Noebe, RD AF Bozzolo, G Noebe, RD TI Analysis of surface and bulk behavior in Ni-Pd alloys SO ACTA MATERIALIA LA English DT Article DE surface segregation; modeling; nickel alloys; platinum group; ordering ID THERMODYNAMIC PROPERTIES; SEGREGATION PROFILE; SOLID-SOLUTIONS; CU-AG; REACTIVITY; METAL; NI50PD50(100); HYDROGENATION; ORDER; AU AB The most salient features of the surface structure and bulk behavior of Ni-Pd alloys have been studied using the Bozzolo-Ferrante-Smith (BFS) method for alloys. Large-scale atomistic simulations were performed to investigate surface segregation profiles as a function of temperature, crystal face, and composition. Pd enrichment of the first layer was observed in (1 1 1) and (1 0 0) surfaces, and enrichment of the top two layers occurred for (1 1 0) surfaces. In all cases, the segregation profile shows alternated planes enriched and depleted in Pd. In addition, the phase structure of bulk Ni-Pd alloys as a function of temperature and composition was studied. A weak ordering tendency was observed at low temperatures, which helps to explain the compositional oscillations in the segregation profiles. Finally, based on atom-by-atom static energy calculations, a comprehensive explanation for the observed surface and bulk features will be presented in terms of competing chemical and strain energy effects. (C) 2003 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Cleveland, OH 44142 USA. RP Bozzolo, G (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd,Mail Stop 23-2, Cleveland, OH 44135 USA. NR 33 TC 12 Z9 14 U1 1 U2 4 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 SEP 3 PY 2003 VL 51 IS 15 BP 4395 EP 4409 DI 10.1016/S1359-6465(03)00275-1 PG 15 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 715FX UT WOS:000184961400003 ER PT J AU Grenfell, JL Shindell, DT Grewe, V AF Grenfell, JL Shindell, DT Grewe, V TI Sensitivity studies of oxidative changes in the troposphere in 2100 using the GISS GCM SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID GENERAL-CIRCULATION MODEL; CHEMISTRY-CLIMATE INTERACTIONS; OH CONCENTRATIONS; FUTURE CHANGES; OZONE; IMPACT; SIMULATION; NOX; ATMOSPHERE; EMISSIONS AB We examine the relative importance of chemical precursor emissions affecting ozone (O-3) and hydroxyl (OH) for the year 2100. Runs were developed from the Comparison of Tropospheric Oxidants (Ox_Comp) modeling workshop year 2100 A2p emissions scenario, part of the Intergovernmental Panel on Climate Change (IPCC) third assessment report (TAR). While TAR examined only cumulative change, we examine individual components (NOx, CH4, CO, etc.). Also, since there will be climate changes in 2100 (not accounted for by TAR), we investigate the effect of changing our fixed SSTs/ocean ice from present day to 2100 conditions, as projected by a coupled ocean-atmosphere model with doubled CO2. Unlike TAR we perform multiannual integrations and we include interactive lightning. Largest changes arose from the run with 2100 industrial NOx (O-3=+16.9%, OH=+29.4% in July) and the run with 2100 methane (O-3=+17.4%, OH=-19.1% in July). In the latter run, large ozone increases in the NH upper troposphere appeared to repartition HO2 into OH to such an extent that the lowering in OH associated with increased methane was overwhelmed in that region. Incorporating all changes collectively led to the July tropospheric ozone burden increasing from 426 to 601 Tg (+41.1%) and the July OH concentration increasing from 13.6 to 15.2 x 10(5) molecules/cm(3) (+11.8%). C1 Columbia Univ, Ctr Climate Syst Res, New York, NY USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Grenfell, JL (reprint author), Free Univ Berlin, Inst Meteorol, Stratospharengrp, D-1000 Berlin, Germany. RI Shindell, Drew/D-4636-2012; Grewe, Volker/A-6147-2011 OI Grewe, Volker/0000-0002-8012-6783 NR 38 TC 13 Z9 14 U1 0 U2 1 PU EUROPEAN GEOPHYSICAL SOC PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD SEP 3 PY 2003 VL 3 BP 1267 EP 1283 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 718JH UT WOS:000185141100001 ER PT J AU Bertucci, C Mazelle, C Slavin, JA Russell, CT Acuna, MH AF Bertucci, C Mazelle, C Slavin, JA Russell, CT Acuna, MH TI Magnetic field draping enhancement at Venus: Evidence for a magnetic pileup boundary SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND INTERACTION; MARS GLOBAL SURVEYOR; PLASMA OBSERVATIONS; UP BOUNDARY; MAGNETOSPHERE; MAGNETOTAIL; SIMULATION; HALLEY AB [1] The absence of a global-scale dynamo-generated magnetic field and the existence of an ionosphere at Venus and Mars caused many to predict that their solar wind interaction would be similar. After Pioneer Venus Orbiter (PVO) observations, it was concluded that the global aspects of the Venusian interaction could be well described by single-fluid models. According to these models, the magnetic field draping should develop progressively from the shock down to the ionopause. A recent study at Mars, where a "Venus-like'' interaction was expected, showed that draping is prominent only inside the magnetic pileup boundary (MPB), a well-defined plasma boundary located between the shock and the ionopause first reported at comets, but never at Venus. From an identical analysis on PVO magnetometer data, we report a dramatic enhancement of draping on the dayside of Venus. Then, we deduce the existence of a Venusian counterpart of the Martian and cometary MPB. C1 CESR, F-31028 Toulouse 4, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. RP Bertucci, C (reprint author), CESR, 9 Ave Colonel Roche, F-31028 Toulouse 4, France. RI Slavin, James/H-3170-2012 OI Slavin, James/0000-0002-9206-724X NR 22 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 SEP 3 PY 2003 VL 30 IS 17 AR 1876 DI 10.1029/2003GL017271 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 722DT UT WOS:000185360700001 ER PT J AU Browell, EV Fenn, MA Butler, CF Grant, WB Brackett, VG Hair, JW Avery, MA Newell, RE Hu, YL Fuelberg, HE Jacob, DJ Anderson, BE Atlas, EL Blake, DR Brune, WH Dibb, JE Fried, A Heikes, BG Sachse, GW Sandholm, ST Singh, HB Talbot, RW Vay, SA Weber, RJ Bartlett, KB AF Browell, EV Fenn, MA Butler, CF Grant, WB Brackett, VG Hair, JW Avery, MA Newell, RE Hu, YL Fuelberg, HE Jacob, DJ Anderson, BE Atlas, EL Blake, DR Brune, WH Dibb, JE Fried, A Heikes, BG Sachse, GW Sandholm, ST Singh, HB Talbot, RW Vay, SA Weber, RJ Bartlett, KB TI Large-scale ozone and aerosol distributions, air mass characteristics, and ozone fluxes over the western Pacific Ocean in late winter/early spring SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ozone; aerosols; fluxes; air mass characteristics; western Pacific; TRACE-P ID LONG-RANGE TRANSPORT; EXPLORATORY MISSION-WEST; EAST-ASIA; NORTH-AMERICA; PEM-WEST; CHEMICAL CHARACTERISTICS; CONTINENTAL OUTFLOW; TROPOSPHERIC OZONE; DIAL MEASUREMENTS; CARBON-MONOXIDE AB [1] Large-scale measurements of ozone (O-3) and aerosol distributions were made from the NASA DC-8 aircraft during the Transport and Chemical Evolution over the Pacific (TRACE-P) field experiment conducted in February-April 2001. Remote measurements were made with an airborne lidar to provide O-3 and multiple-wavelength aerosol backscatter profiles from near the surface to above the tropopause along the flight track. In situ measurements of O-3, aerosols, and a wide range of trace gases were made onboard the DC-8. Five-day backward trajectories were used in conjunction with the O-3 and aerosol distributions on each flight to indicate the possible origin of observed air masses, such as from biomass burning regions, continental pollution, desert regions, and oceanic regions. Average latitudinal O-3 and aerosol scattering ratio distributions were derived from all flights west of 150degreesE, and these distributions showed the average latitude and altitude dependence of different dynamical and chemical processes in determining the atmospheric composition over the western Pacific. TRACE-P (TP) showed an increase in the average latitudinal distributions of both O-3 and aerosols compared to PEM-West B (PWB), which was conducted in February-March 1994. O-3, aerosol, and potential vorticity levels were used to identify nine air mass types and quantify their frequency of occurrence as a function of altitude. This paper discusses the characteristics of the different air mass types encountered during TP and compares them to PWB. These results confirmed that most of the O-3 increase in TP was due to photochemistry. The average latitudinal eastward O-3 flux in the western Pacific during TP was found to peak near 32degreesN with a total average O-3 flux between 14 and 46degreesN of 5.2 Tg/day. The eastward total CO flux was calculated to be 2.2 Tg-C/day with -6% estimated from Asia. The Asian flux of CO2 and CH4 was estimated at 4.9 and 0.06 Tg-C/day. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Sci Applicat Int Corp, Hampton, VA USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA USA. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80307 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92717 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Univ New Hampshire, Inst Study Earth Oceans & Space, Durham, NH 03824 USA. Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. Georgia Inst Technol, Dept Earth & Atmospher Sci, Atlanta, GA 30332 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP NASA, Langley Res Ctr, MS-410A, Hampton, VA 23681 USA. EM Edward.V.Browell@nasa.gov RI Grant, William/B-8311-2009; Atlas, Elliot/J-8171-2015 OI Grant, William/0000-0002-1439-3285; NR 45 TC 37 Z9 37 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 3 PY 2003 VL 108 IS D20 AR 8805 DI 10.1029/2002JD003290 PG 26 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 722EE UT WOS:000185361800002 ER PT J AU Miyazaki, Y Kondo, Y Koike, M Fuelberg, HE Kiley, CM Kita, K Takegawa, N Sachse, GW Flocke, F Weinheimer, AJ Singh, HB Eisele, FL Zondlo, M Talbot, RW Sandholm, ST Avery, MA Blake, DR AF Miyazaki, Y Kondo, Y Koike, M Fuelberg, HE Kiley, CM Kita, K Takegawa, N Sachse, GW Flocke, F Weinheimer, AJ Singh, HB Eisele, FL Zondlo, M Talbot, RW Sandholm, ST Avery, MA Blake, DR TI Synoptic-scale transport of reactive nitrogen over the western Pacific in spring SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE warm conveyor belts; convection; reactive nitrogen; TRACE-P; western Pacific ID NORTH-ATLANTIC OCEAN; BIOMASS BURNING EMISSIONS; TRACE GAS-COMPOSITION; FREE TROPOSPHERE; BOUNDARY-LAYER; MIDLATITUDE CYCLONES; EAST-ASIA; OZONE; DISTRIBUTIONS; IMPACT AB [1] Pathways of synoptic-scale uplifted transport of pollutants from East Asia and their effects on chemical distributions of NOy species are investigated based on a subset of the aircraft data obtained during the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) experiment, conducted in February-April 2001. Meteorological and chemical analyses indicate that 73% of the uplifted transport was associated with warm conveyor belts (WCBs) and convective outflow (COF), which transported air masses strongly impacted by biomass burning over Southeast Asia. The rest (27%) of the uplifted air masses originated over coastal regions of northeast China, where fossil fuel combustion was a dominant source of pollutants. Both WCB associated with a midlatitude cyclone and COF associated with a stationary front over southeast China are examined in detail for the April 4 case. During the TRACE-P period, low NOx(= NO + NO2)/ NOy ratios in the WCB and COF indicate that a significant part of the NOx was oxidized to nitric acid (HNO3) and peroxyacetyl nitrate (PAN) during transport. Low HNO3/NOy ratios in the WCB and COF airstreams indicate that a large amount of HNO3 was removed during transport on timescales within 1-3 days. PAN was found to be the dominant form of NOy in air masses transported by the WCB and COF, likely due to the production of PAN in regions of biomass burning and industrial emissions, as well as due to the rapid removal of HNO3 during transport. For emissions that were transported to the free troposphere by WCBs and COF, about 10-20% of the NOy remained after transport to the free troposphere, and 30% of the NOy surviving in the boundary layer in limited cases. The results indicate that the WCB and COF provide both an efficient sink for HNO(3 a)nd an efficient mechanism for the transport of PAN from the boundary layer to the free troposphere over the western Pacific. C1 Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, Tokyo 1538904, Japan. Univ Tokyo, Grad Sch Sci, Tokyo 1130033, Japan. Florida State Univ, Dept Meteorol, Tallahassee, FL 32306 USA. Ibaraki Univ, Dept Environm Sci, Ibaraki 3108512, Japan. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Natl Ctr Atmospher Res, Div Atmospher Chem, Boulder, CO 80303 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ New Hampshire, Durham, NH 03820 USA. Georgia Inst Technol, Atlanta, GA 30332 USA. Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. RP Univ Tokyo, Adv Sci & Technol Res Ctr, Meguro Ku, 4-6-1 Komaba, Tokyo 1538904, Japan. EM yuzom@atmos.rcast.u-tokyo.ac.jp; kondo@atmos.rcast.u-tokyo.ac.jp; koike@eps.s.u-tokyo.ac.jp; fuelberg@huey.met.fsu.edu; ckiley@met.fsu.edu; kita@env.sci.ibaraki.ac.jp; takegawa@atmos.rcast.u-tokyo.ac.jp; g.w.sachse@larc.nasa.gov; ffl@acd.ucar.edu; wein@ucar.edu; hsingh@mail.arc.nasa.gov; eisele@ncar.ucar.edu; zondlo@ucar.edu; robert.talbot@unh.edu; scott.sandholm@eas.gatech.edu; m.a.avery@larc.nasa.gov; drblake@uci.edu RI Koike, Makoto/F-4366-2011; Kondo, Yutaka/D-1459-2012; Miyazaki, Yuzo/C-6920-2010; Zondlo, Mark/R-6173-2016 OI Zondlo, Mark/0000-0003-2302-9554 NR 51 TC 54 Z9 53 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 3 PY 2003 VL 108 IS D20 AR 8788 DI 10.1029/2002JD003248 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 722EE UT WOS:000185361800001 ER PT J AU Comstock, RL Bills, BG AF Comstock, RL Bills, BG TI A solar system survey of forced librations in longitude SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE librations; moments of inertia; spin states; synchronous; resonant; nonresonant ID INTERNAL STRUCTURE; GRAVITY-FIELD; INTERIOR STRUCTURE; PHYSICAL LIBRATIONS; MOLTEN CORE; THERMAL EVOLUTION; MARS PATHFINDER; MAGNETIC-FIELD; PLANET MERCURY; VENUS GRAVITY AB Forced librations are periodic rotational rate variations due to gravitational interactions with an orbital partner. We have developed an analytic theory capable of calculating expected amplitudes of forced librations for nonresonant rotators as well as for bodies existing in a spin-orbit resonance. The theory has been applied to 34 solar system bodies, including terrestrial planets, planetary satellites, and the asteroid Eros. Parameters governing libration amplitude are the body's orbital eccentricity, moment difference, and the ratio of its spin rate to its orbital rate. In each case the largest libration amplitude is associated with the forcing frequency 2 (p - 1) n, where n is the orbital mean motion and p is the spin/orbit rate ratio. This dominant frequency is simply semidiurnal as seen from the position of the torquing body. The maximum libration angular amplitude is 1.3 x 10(-2) radians for Thebe, and the maximum mean equatorial displacement is 1.4 km for Mimas. C1 Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Comstock, RL (reprint author), Univ Calif San Diego, Scripps Inst Oceanog, 9500 Gilman Dr, La Jolla, CA 92093 USA. RI Bills, Bruce/C-1156-2008 NR 74 TC 26 Z9 26 U1 2 U2 16 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD SEP 3 PY 2003 VL 108 IS E9 AR 5100 DI 10.1029/2003JE002100 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 722FD UT WOS:000185364000003 ER PT J AU Asano, S Fan, W Zhou, CW Ng, HT Han, J Meyyapan, M AF Asano, S Fan, W Zhou, CW Ng, HT Han, J Meyyapan, M TI Synthesis and CV studies of new dithiol-terminated metal-terpyridine complexes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NY SP Amer Chem Soc C1 NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA. Univ So Calif, Dept Elect Engn Electrophys, Los Angeles, CA 90089 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 423-INOR BP U738 EP U738 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JF UT WOS:000187062403532 ER PT J AU Chaban, GM AF Chaban, GM TI Theoretical studies of chemical reactions following electronic excitation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NEW YORK SP Amer Chem Soc C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM chaban@nas.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 202-PHYS BP U300 EP U300 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JG UT WOS:000187062501490 ER PT J AU Chen, B Ng, HT Li, J Meyyapan, M AF Chen, B Ng, HT Li, J Meyyapan, M TI Optical spectroscopy study of ZnO and other nanowires. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NY SP Amer Chem Soc C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM bchen@mail.arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 574-INOR BP U762 EP U762 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JF UT WOS:000187062403682 ER PT J AU Chipara, M Zaleski, JM Banks, BA Dever, J De Groh, K Balascuta, S AF Chipara, M Zaleski, JM Banks, BA Dever, J De Groh, K Balascuta, S TI ESR investigations of proton irradiation effects in polyimides. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NEW YORK SP Amer Chem Soc C1 Indiana Univ, Cyclotron Facil, Bloomington, IN 47408 USA. Indiana Univ, Dept Chem, Bloomington, IN 47408 USA. Indiana Univ, Dept Phys, Bloomington, IN 47405 USA. NASA, Glenn Res Ctr, Electrophys Branch, Brookpark, OH USA. EM mchipara@iucf.indiana.edu RI Chipara, Mircea/B-2849-2009; Balascuta, Septimiu/J-7679-2015; Chipara, Mircea/F-1552-2011 OI Balascuta, Septimiu/0000-0003-2331-294X; Chipara, Mircea/0000-0003-3584-4863 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 251-PMSE BP U497 EP U498 PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 751JG UT WOS:000187062502586 ER PT J AU Clark, RN Swayze, G Hoefen, T Livo, E Sutley, S Meeker, G Plumlee, G Brownfield, I Lamothe, PJ Gent, C Morath, L Taggart, J Theodorakos, P Adams, M Green, R Pavri, B Sarture, C Vance, S Boardman, J AF Clark, RN Swayze, G Hoefen, T Livo, E Sutley, S Meeker, G Plumlee, G Brownfield, I Lamothe, PJ Gent, C Morath, L Taggart, J Theodorakos, P Adams, M Green, R Pavri, B Sarture, C Vance, S Boardman, J TI Environmental mapping with imaging spectroscopy of the World Trade Center area after the September 11, 2001 attack. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NY SP Amer Chem Soc C1 US Geol Survey, Denver Fed Ctr, Denver, CO 80225 USA. Jet Propuls Lab, Pasadena, CA 91109 USA. US EPA, Washington, DC 20460 USA. EM rclark@usgs.gov NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 110-ENVR BP U485 EP U485 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JF UT WOS:000187062402312 ER PT J AU Dean, DR Ganguli, S Abdalla, M Campbell, S Vaia, R Jose, M AF Dean, DR Ganguli, S Abdalla, M Campbell, S Vaia, R Jose, M TI High temperature thermoset nanocomposites. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NEW YORK SP Amer Chem Soc C1 Tuskegee Univ, TCAM, Tuskegee, AL 36088 USA. NASA, Glenn Res Ctr, Brookpark, OH USA. USAF, Res Lab, Mat & Mfg Directorate, Washington, DC USA. EM deand@acd.tusk.edu NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 433-PMSE BP U526 EP U526 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JG UT WOS:000187062502767 ER PT J AU Fletcher, GD AF Fletcher, GD TI Parallel multiconfigurational self-consistent field. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NEW YORK SP Amer Chem Soc C1 Eloret Corp, NASA, Ames Res Ctr, NAS Div,Computat Chem Grp, Moffett Field, CA 94035 USA. EM gfletcher@arc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 439-PHYS BP U336 EP U336 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JG UT WOS:000187062501721 ER PT J AU Huang, C Zhang, QM Xia, F Wang, Q Su, J AF Huang, C Zhang, QM Xia, F Wang, Q Su, J TI New avenues to achieve high dielectric constant and high electromechanical response in electroactive polymers SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NEW YORK SP Amer Chem Soc C1 Penn State Univ, Dept Elect Engn, University Pk, PA 16802 USA. Penn State Univ, Mat Res Inst, University Pk, PA 16802 USA. Penn State Univ, Mat Sci & Engn Dept, University Pk, PA 16802 USA. NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA USA. EM cxh57@psu.edu NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 561-POLY BP U441 EP U441 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JG UT WOS:000187062502323 ER PT J AU Koehne, J Li, J Chen, H Cassell, A Ng, HT Fan, W Li, Q Han, J Mayyappan, M AF Koehne, J Li, J Chen, H Cassell, A Ng, HT Fan, W Li, Q Han, J Mayyappan, M TI Carbon nanotube nanoelectrode array for ultrasensitive DNA detection. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NY SP Amer Chem Soc C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM jkoehne@mail.arc.nasa.gov NR 0 TC 1 Z9 1 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 121-ANYL BP U119 EP U120 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 751JF UT WOS:000187062400510 ER PT J AU Lombardi, RA Cao, XL Kim, SS Dukor, RK Nafie, LA AF Lombardi, RA Cao, XL Kim, SS Dukor, RK Nafie, LA TI Detection of chirality in solid-state amino acids using Fourier-transform vibrational circular dichroism. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NY SP Amer Chem Soc C1 Syracuse Univ, Dept Chem, Ctr Sci & Technol 1 014, Syracuse, NY 13244 USA. Jet Prop Lab, Pasadena, CA 91109 USA. EM ralombar@syr.edu NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 195-BIOL BP U183 EP U183 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JF UT WOS:000187062400784 ER PT J AU MacDougall, PJ Henze, CE AF MacDougall, PJ Henze, CE TI Fleshing-out pharmacophores with volume rendering of molecular charge densities and hyperwall visualization technology. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NY SP Amer Chem Soc C1 Middle Tennessee State Univ, Dept Chem, Murfreesboro, TN 37132 USA. NASA, Ames Res Ctr, Data Anal Grp, Ames, IA USA. EM pmacdougall@mtsu.edu RI MacDougall, Preston/N-2515-2016 OI MacDougall, Preston/0000-0002-0403-000X NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 054-COMP BP U431 EP U431 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JF UT WOS:000187062402003 ER PT J AU Shindell, D AF Shindell, D TI Chemistry - Climate interactions in the atmosphere. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NY SP Amer Chem Soc C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. EM dshindell@giss.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 016-PRES BP U23 EP U23 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JF UT WOS:000187062400016 ER PT J AU Vander Wal, RL Tomasek, AJ AF Vander Wal, RL Tomasek, AJ TI Nanostructure effects upon soot oxidation. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NY SP Amer Chem Soc C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 3 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 121-FUEL BP U564 EP U564 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JF UT WOS:000187062402661 ER PT J AU Williams, MK Weiser, ES Grimsley, BW Nelson, GL Brenner, JR AF Williams, MK Weiser, ES Grimsley, BW Nelson, GL Brenner, JR TI Density effects in high performance polyimide foam materials. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NEW YORK SP Amer Chem Soc C1 NASA, Testbed Technol Branch, Kennedy Space Ctr, FL 32899 USA. NASA, Langley Res Ctr, Hampton, VA USA. Florida Inst Technol, Melbourne, FL 32901 USA. EM martha.williams-1@ksc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 491-PMSE BP U535 EP U535 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JG UT WOS:000187062502825 ER PT J AU Xia, F Xu, TB Huang, C Tadigadapa, S Zhang, QM AF Xia, F Xu, TB Huang, C Tadigadapa, S Zhang, QM TI Poly(vinylidene fluoroethylene-trifluoroethylene) based high performance electroactive polymers for BioMEMs. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 226th National Meeting of the American-Chemical-Society CY SEP 07-11, 2003 CL NEW YORK, NEW YORK SP Amer Chem Soc C1 Penn State Univ, Mat Res Inst, University Pk, PA 16802 USA. Penn State Univ, Dept Elect Engn, University Pk, PA 16802 USA. NASA, LaRC, Hampton, VA USA. EM fxx2@psu.edu NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD SEP PY 2003 VL 226 MA 187-POLY BP U383 EP U383 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 751JG UT WOS:000187062501955 ER PT J AU Bednarcyk, BA Arnold, SM AF Bednarcyk, BA Arnold, SM TI Micromechanics-based modeling of woven polymer matrix composites SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 42nd Structures, Structural Dynamics, and Materials Conference CY APR 16-19, 2001 CL SEATTLE, WASHINGTON SP Amer Inst Aeronaut & Astronaut, ASME, ASCE, AHS, ASC ID FABRIC COMPOSITES; CARBON/COPPER COMPOSITE; INELASTIC RESPONSE; ELASTIC PROPERTIES; MODULI; CELLS AB A novel approach is combined with the generalized method of cells (GMC) to predict the elastic properties of plain-weave polymer matrix composites (PMCs). The traditional one-step three-dimensional homogenization procedure that has been used in conjunction with GMC for modeling woven composites in the past is inaccurate due to the lack of shear coupling inherent in the model. However, by performing a two-step homogenization procedure in which the woven composite repeating unit cell is homogenized independently in the through-the-thickness direction prior to homogenization in the plane of the weave, GMC can now accurately model woven PMCs. This two-step procedure is outlined and implemented, and predictions are compared with results from the traditional one-step approach as well as other model and experimental results from the literature. Full coupling of this two-step technique within the recently developed Micromechanics Analysis Code with GMC software package will result in a widely applicable, efficient, and accurate tool for the design and analysis of woven composite materials and structures. C1 Univ Virginia, Dept Civil Engn, Charlottesville, VA 22904 USA. NASA, John H Glenn Res Ctr Lewis Field, Struct Div, Life Predict Branch, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Brookpark, OH 44142 USA. RP Bednarcyk, BA (reprint author), Univ Virginia, Dept Civil Engn, Charlottesville, VA 22904 USA. NR 23 TC 17 Z9 17 U1 0 U2 7 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD SEP PY 2003 VL 41 IS 9 BP 1788 EP 1796 DI 10.2514/2.7297 PG 9 WC Engineering, Aerospace SC Engineering GA 716CF UT WOS:000185010700017 ER PT J AU Morris, PJ Farassat, E AF Morris, PJ Farassat, E TI Comment on "Acoustic analogy and alternative theories for jet noise prediction" - Reply by the authors to C. K. W. Tam SO AIAA JOURNAL LA English DT Editorial Material ID SOUND C1 Penn State Univ, Dept Aerosp Engn, University Pk, PA 16802 USA. NASA, Langley Res Ctr, Aeroacoust Branch, Hampton, VA 23681 USA. RP Morris, PJ (reprint author), Penn State Univ, Dept Aerosp Engn, University Pk, PA 16802 USA. NR 13 TC 4 Z9 5 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD SEP PY 2003 VL 41 IS 9 BP 1845 EP 1847 DI 10.2514/2.7309 PG 3 WC Engineering, Aerospace SC Engineering GA 716CF UT WOS:000185010700028 ER PT J AU Koh, CG Tan, W Zhao, MQ Ricco, AJ Fan, ZH AF Koh, CG Tan, W Zhao, MQ Ricco, AJ Fan, ZH TI Integrating polymerase chain reaction, valving, and electrophoresis in a plastic device for bacterial detection SO ANALYTICAL CHEMISTRY LA English DT Article ID DNA ANALYSIS DEVICE; CAPILLARY-ELECTROPHORESIS; MICROFLUIDIC DEVICES; PCR AMPLIFICATION; ESCHERICHIA-COLI; IDENTIFICATION; SYSTEM; CHIP; FLOW; OPTIMIZATION AB An integrated plastic microfluidic device was designed and fabricated for bacterial detection and identification. The device, made from poly(cyclic olefin) with integrated graphite ink electrodes and photopatterned gel domains, accomplishes DNA amplification, microfluidic valving, sample injection, on-column labeling, and separation. Polymerase chain reaction (PCR) is conducted in a channel reactor containing a volume as small as 29 nL; thermal cycling utilizes screen-printed graphite ink resistors. In situ gel polymerization was employed to form local microfluidic valves that minimize convective flow of the PCR mixture into other regions. After PCR, amplicons (products) are electrokinetically injected through the gel valve, followed by on-chip electrophoretic separation. An intercalating dye is admixed to label the amplicons; they are detected using laser-induced fluorescence. Two model bacteria, Escherichia coli O157 and Salmonella typhimurium, were chosen to demonstrate bacterial detection and identification based on amplification of several of their unique DNA sequences. The limit of detection is about six copies of target DNA. C1 ACLARRA Biosci Inc, Mountain View, CA 94043 USA. RP Ricco, AJ (reprint author), NASA, Ames Res Ctr, Mountain View, CA 94035 USA. RI Fan, Z./A-5886-2008; Ricco, Antonio/A-5273-2010; OI Fan, Z./0000-0002-1812-8016; Ricco, Antonio/0000-0002-2355-4984 NR 45 TC 143 Z9 148 U1 1 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 2003 VL 75 IS 17 BP 4591 EP 4598 DI 10.1021/ac0343836 PG 8 WC Chemistry, Analytical SC Chemistry GA 719FE UT WOS:000185192300042 PM 14632069 ER PT J AU Woodcraft, AL Sudiwala, RV Ade, PAR Griffin, MJ Wakui, E Bhatia, RS Lange, AE Bock, JJ Turner, AD Yun, MH Beeman, JW AF Woodcraft, AL Sudiwala, RV Ade, PAR Griffin, MJ Wakui, E Bhatia, RS Lange, AE Bock, JJ Turner, AD Yun, MH Beeman, JW TI Predicting the response of a submillimeter bolometer to cosmic rays SO APPLIED OPTICS LA English DT Article ID SEMICONDUCTOR BOLOMETERS AB Bolometers designed to detect. submillimeter radiation also respond to cosmic, gamma, and x rays. Because detectors cannot be fully shielded from such energy sources, it is necessary to understand the effect of a photon or cosmic-ray particle being absorbed. The resulting signal (known as a glitch) can then be removed from raw data. We present measurements using an Americium-241 gamma radiation source to irradiate a prototype bolometer for the High Frequency Instrument in the Planck Surveyor satellite. Our measurements showed no variation in response depending on where the radiation was absorbed, demonstrating that the bolometer absorber and thermistor thermalize quickly. The bolometer has previously been fully characterized both electrically and optically. We find that using optically measured time constants underestimates the time taken for the detector to recover from a radiation absorption event. However, a full thermal model for the bolometer, with parameters taken from electrical and optical measurements, provides accurate time constants. Slight deviations from the model were seen at high energies; these can be accounted for by use of an extended model. (C) 2003 Optical Society of America. C1 Cardiff Univ, Dept Phys & Astron, Cardiff CF24 3YB, S Glam, Wales. Queen Mary Univ London, Dept Phys, London E1 4NS, England. CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Woodcraft, AL (reprint author), Cardiff Univ, Dept Phys & Astron, POB 913, Cardiff CF24 3YB, S Glam, Wales. EM adam.woodcraft@physics.org NR 11 TC 7 Z9 7 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 2003 VL 42 IS 25 BP 5009 EP 5016 DI 10.1364/AO.42.005009 PG 8 WC Optics SC Optics GA 715GQ UT WOS:000184963200002 PM 12962375 ER PT J AU Wu, MC Rogowski, RS AF Wu, MC Rogowski, RS TI Fabrication of self-apodized short-length fiber Bragg gratings SO APPLIED OPTICS LA English DT Article ID OPTICAL-FIBER; STRAIN AB A new technique for writing extremely short-length Bragg gratings in optical fibers is demonstrated. A physical model describes the diffraction effects on the spatial and wavelength spectra of the Bragg gratings. Selection of appropriate diffraction patterns and related parameters permits self-apodized Bragg gratings with a typical spatial length of several hundred micrometers and a bandwidth of several nanometers to be obtained. These gratings with well-defined spectra are suitable for use as miniature distributed strain sensors and other applications requiring small physical dimensions and broadband spectra. (C) 2003 Optical Society of America. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Wu, MC (reprint author), NASA, Langley Res Ctr, Mail Stop 231, Hampton, VA 23681 USA. EM m.c.wu@larc.nasa.gov NR 13 TC 6 Z9 6 U1 4 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 2003 VL 42 IS 25 BP 5017 EP 5023 DI 10.1364/AO.42.005017 PG 7 WC Optics SC Optics GA 715GQ UT WOS:000184963200003 PM 12962376 ER PT J AU Benford, DJ Gaidis, MC Kooi, JW AF Benford, DJ Gaidis, MC Kooi, JW TI Optical properties of Zitex in the infrared to submillimeter SO APPLIED OPTICS LA English DT Article ID POLYSTYRENE; CONSTANTS AB The results of measurements of the refractive index and power attenuation coefficient of Zitex at 290, 77, and 4 K in the spectral region from 1 to 1000 mum are presented. Zitex is a porous Teflon sheet with a filling factor of similar to50% and is manufactured in several varieties as a filter paper. Zitex is found to be an effective IR block, with thin (200-mum) sheets transmitting less than 1% in the 1-50-mum range while attenuating less than or similar to10% at wavelengths longer than 200 mum. Some variation in the cutoff wavelength is seen, tending to be a shorter-wavelength cutoff for a smaller pore size. In addition, the thermal conductivity of Zitex at cryogenic temperatures has been measured and is found to be roughly one half that of bulk Teflon. Finally, its dielectric constant has been measured in the submillimeter as n = 1.20, resulting in extremely low dielectric reflection losses. As a result, Zitex is particularly useful as an IR blocking filter in low-noise heterodyne receivers; in the millimeter-wave range (lambda greater than or similar to 850 mum or nu less than or equal to 350 GHz) the attenuation of alpha less than or equal to 0.01 cm(-1) for a 3.5-mm thickness filter of Zitex G125 would raise receiver noise temperatures by <1 K. (C) 2003 Optical Society of America. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. IBM Corp, ZIP 33F, Hopewell Jct, NY 12533 USA. CALTECH, Pasadena, CA 91125 USA. RP Benford, DJ (reprint author), NASA, Goddard Space Flight Ctr, Code 685, Greenbelt, MD 20771 USA. EM dominic.benford@gsfc.nasa.gov RI Benford, Dominic/D-4760-2012; Gaidis, Michael/D-3327-2013 OI Benford, Dominic/0000-0002-9884-4206; NR 16 TC 33 Z9 34 U1 0 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 2003 VL 42 IS 25 BP 5118 EP 5122 DI 10.1364/AO.42.005118 PG 5 WC Optics SC Optics GA 715GQ UT WOS:000184963200017 PM 12962390 ER PT J AU Qiu, YM Uhl, D Chacon, R Yang, RQ AF Qiu, YM Uhl, D Chacon, R Yang, RQ TI Lasing characteristics of InAs quantum-dot lasers on (001) InP substrate SO APPLIED PHYSICS LETTERS LA English DT Article ID DASH LASERS; MU-M; WAVELENGTH AB Single-stack InAs self-assembled quantum-dot (QD) lasers based on (001) InP substrates have been grown by metalorganic vapor-phase epitaxy. The narrow ridge waveguide lasers lased up to 260 K in continuous-wave operation, and near room temperature in pulsed mode, with emission wavelengths between 1.59 to 1.74 mum. Above 200 K, a very low wavelength temperature sensitivity of 0.09 nm/K was observed. Lasing spectra at different temperatures suggests that the ground states and the excited states almost overlap, and form a quasicontinuous band due to the large size of the InAs dots and their inhomogeneous broadening. These results will provide guidance for further development of long wavelength InAs QD lasers based on InP substrates. (C) 2003 American Institute of Physics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Qiu, YM (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 10 TC 50 Z9 50 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 SEP 1 PY 2003 VL 83 IS 9 BP 1704 EP 1706 DI 10.1063/1.1606501 PG 3 WC Physics, Applied SC Physics GA 715VB UT WOS:000184992000006 ER PT J AU Rodriguez, P Trivedi, S Jin, F Wang, CC Stepanov, S Elliott, G Meyers, JF Lee, J Khurgin, J AF Rodriguez, P Trivedi, S Jin, F Wang, CC Stepanov, S Elliott, G Meyers, JF Lee, J Khurgin, J TI Pulsed-laser vibrometer using photoelectromotive-force sensors SO APPLIED PHYSICS LETTERS LA English DT Article ID ADAPTIVE PHOTODETECTORS AB We demonstrate experimentally significant improvement in the sensitivity of photoelectromotive-force (photo-EMF) laser vibrometers using pulsed-light sources. The vibrating surface is discretely sampled by individual laser pulses and recorded by the photo-EMF sensor via the generation of photocurrent pulses whose magnitudes are proportional to the instantaneous surface displacements. With a sufficiently high sampling rate, reconstruction of the vibration wave form can be achieved by conducting envelope (or peak) detection of the resultant series of photocurrent pulses. Significantly higher peak optical power levels of the probe laser pulses, which can be orders of magnitude greater than those of continuous-wave interrogation lasers with the same average power, lead to proportional enhancement in the photo-EMF response and remarkable improvement in detection sensitivity when the photodetection process is initially amplifier noise current limited. (C) 2003 American Institute of Physics. C1 Brimrose Corp Amer, Baltimore, MD 21236 USA. Inst Nacl Astrofis Opt & Elect, Puebla, Mexico. Univ Illinois, Dept Aeronaut & Astronaut Engn, Urbana, IL 61801 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Johns Hopkins Univ, Dept Elect & Comp Engn, Baltimore, MD 21218 USA. RP Rodriguez, P (reprint author), Brimrose Corp Amer, 7720 Belair Rd, Baltimore, MD 21236 USA. RI khurgin, Jacob/A-3278-2010 NR 8 TC 14 Z9 14 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 1 PY 2003 VL 83 IS 9 BP 1893 EP 1895 DI 10.1063/1.1606882 PG 3 WC Physics, Applied SC Physics GA 715VB UT WOS:000184992000069 ER PT J AU Blumberg, BS AF Blumberg, BS TI The NASA astrobiology institute: Early history and organization SO ASTROBIOLOGY LA English DT Article DE NASA Astrobiology Institute; astrobiology; organization; collaboration; history AB The NASA Astrobiology Institute WAD was established as a means to advance the field of astrobiology by providing a multidisciplinary, multi-institution, science-directed program, executed by universities, research institutes, and NASA and other government laboratories. The scientific community and NASA defined the science content at several workshops as summarized in the NASA Astrobiology Roadmap. Teams were chosen nationwide, following the recommendations of external review groups, and the research program began in 1998. There are now 16 national Teams and five international affiliated and associated astrobiology institutions. The NAI has attracted an outstanding group of scientific groups and individuals. The Institute facilitates the involvement of the scientists in its scientific and management vision. Its goal is to support basic research and allow the scientists the freedom to select their projects and alter them as indicated by new research. Additional missions include the education of the public, the involvement of students who will be the astrobiologists of future generations, and the development of a culture of collaboration in NAI, a "virtual institute," spread across many sites nationally and internationally. C1 Fox Chase Canc Ctr, NASA, Philadelphia, PA 19111 USA. RP Blumberg, BS (reprint author), Fox Chase Canc Ctr, NASA, 7701 Burholme Ave, Philadelphia, PA 19111 USA. NR 9 TC 11 Z9 11 U1 1 U2 8 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD FAL PY 2003 VL 3 IS 3 BP 463 EP 470 DI 10.1089/153110703322610573 PG 8 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 752HT UT WOS:000187155600001 PM 14678657 ER PT J AU Pilcher, CB AF Pilcher, CB TI Biosignatures of early earths SO ASTROBIOLOGY LA English DT Article DE early life; biosignatures; extrasolar planets; exoplanets ID METHYLATED SULFUR-COMPOUNDS; MICROBIAL MATS; DIMETHYL SULFIDE; OXYGENIC PHOTOSYNTHESIS; ORGANOSULFUR COMPOUNDS; EXTRASOLAR PLANETS; ATMOSPHERIC OXYGEN; CARBON-DIOXIDE; LIFE; SEDIMENTS AB A major goal of NASA's Origins Program is to find habitable planets around other stars and determine which might harbor life. Determining whether or not an extrasolar planet harbors life requires an understanding of what spectral features (i.e., biosignatures) might result from life's presence. Consideration of potential biosignatures has tended to focus,on spectral features of gases in Earth's modem atmosphere, particularly ozone, the photolytic, product of biogenically produced molecular oxygen. But life existed on Earth for about 11/2 billion years before the-buildup of atmospheric oxygen. Inferred characteristics of Earth's earliest biosphere and studies of modem microbial ecosystems that share some of those characteristics suggest that organosulfur compounds, particularly methanethiol (CH3SH the sulfur analog of methanol), may have been biogenic products on early Earth. Similar production could take place on extrasolar Earth-like planets whose biota share functional chemical characteristics with Earth life. Since methanethiol and related organosulfur compounds (as Well as carbon dioxide) a absorb at wavelengths near or overlapping the 9.6-mum band of ozone, there is potential ambig ity in interpreting a feature around this wavelength in an extrasolar planet spectrum. C1 NASA, Off Space Sci, Div Astron & Phys, Washington, DC 20546 USA. RP Pilcher, CB (reprint author), NASA, Off Space Sci, Div Astron & Phys, NASA Headquarters, Washington, DC 20546 USA. NR 88 TC 31 Z9 32 U1 1 U2 15 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD FAL PY 2003 VL 3 IS 3 BP 471 EP 486 DI 10.1089/153110703322610582 PG 16 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 752HT UT WOS:000187155600002 PM 14678658 ER PT J AU Dalton, JB Mogul, R Kagawa, HK Chan, SL Jamieson, CS AF Dalton, JB Mogul, R Kagawa, HK Chan, SL Jamieson, CS TI Near-infrared detection of potential evidence for microscopic organisms on Europa SO ASTROBIOLOGY LA English DT Review DE extraterrestrial life; Europa; infrared spectroscopy; extremophiles ID OUTER SOLAR-SYSTEM; DEINOCOCCUS-RADIODURANS; GALILEAN SATELLITES; WATER ICE; MAPPING SPECTROMETER; REFLECTANCE SPECTRA; SURFACE-COMPOSITION; LOW-TEMPERATURES; ABSORPTION-BAND; LIQUID WATER AB The possibility of an ocean within the icy shell of Jupiter's moon Europa has established that world as a primary candidate in the search for extraterrestrial life within our. Solar System. This paper evaluates the potential to detect evidence for microbial life by comparing laboratory studies of terrestrial microorganisms with measurements from the Galileo Near Infrared Imaging Spectrometer (NIMS). If the interior of Europa at one time harbored life, some evidence may remain in the surface materials. Examination of laboratory spectra of terrestrial extremophiles measured at cryogenic temperatures reveals distorted, asymmetric near-infrared absorption features due to water of hydration. The band centers, widths, and shapes of these features closely match those observed in the Europa spectra. These features are strongest in reddish-brown, disrupted terrains such as linea and chaos regions. Narrow spectral features due to amide bonds in the microbe proteins provide a means of constraining the abundances of such materials using the NIMS data. The NIMS data of disrupted terrains exhibit distorted, asymmetric near-infrared absorption features consistent with the presence of water ice, sulfuric acid octahydrate, hydrated salts, and possibly as much as 0.2 Mg cm(-3) of carbonaceous material that could be of biological origin. However, inherent noise in the observations and limitations of spectral sampling must be taken into account when discussing these findings. C1 SETI Inst, Mountain View, CA USA. Florida Atlantic Univ, Wilkes Honor Coll, Jupiter, FL USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. RP Dalton, JB (reprint author), NASA, Ames Res Ctr, SETI Inst, MS 245-3, Moffett Field, CA 94035 USA. NR 110 TC 32 Z9 32 U1 5 U2 29 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD FAL PY 2003 VL 3 IS 3 BP 505 EP 529 DI 10.1089/153110703322610618 PG 25 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 752HT UT WOS:000187155600005 PM 14678661 ER PT J AU Grasby, SE Allen, CC Longazo, TG Lisle, JT Griffin, DW Beauchamp, B AF Grasby, SE Allen, CC Longazo, TG Lisle, JT Griffin, DW Beauchamp, B TI Supraglacial sulfur springs and associated biological activity in the Canadian high arctic - Signs of life beneath the ice SO ASTROBIOLOGY LA English DT Article; Proceedings Paper CT Annual Meeting of the Geological-Society-of-America CY NOV 01-10, 2001 CL BOSTON, MASSACHUSETTS SP Geol Soc Amer DE sulfur springs; subglacial; bacteria; arctic ID BACTERIUM DESULFOVIBRIO-OXYCLINAE; ANTARCTIC SEA-ICE; SP STRAIN MB; SULFATE REDUCTION; WATER; METABOLISM; GLACIER; ISOTOPE; BIODEGRADATION; IDENTIFICATION AB Unique springs, discharging from the surface of an arctic glacier, release H2S and deposit native sulfur, gypsum, and calcite. The presence of sulfur in three oxidation states indicates a complex series of redox reactions. Physical and chemical conditions of the spring water and surrounding environment, as well as mineralogical and isotopic signatures, suggest biologically mediated reactions. Cell counts and DNA analyses confirm bacteria are present in the spring system, and a limited number of sequenced isolates suggests that complex communities of bacteria live within the glacial system. C1 Geol Survey Canada, Nat Resources Canada, Calgary, AB T2L 2A7, Canada. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Hernandez Engn, Houston, TX USA. US Geol Survey, Ctr Coastal & Watershed Res, St Petersburg, FL USA. RP Grasby, SE (reprint author), Geol Survey Canada, Nat Resources Canada, 3303 33Rd St Nw, Calgary, AB T2L 2A7, Canada. OI Grasby, Stephen/0000-0002-3910-4443 NR 52 TC 46 Z9 47 U1 2 U2 12 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD FAL PY 2003 VL 3 IS 3 BP 583 EP 596 DI 10.1089/153110703322610672 PG 14 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 752HT UT WOS:000187155600011 PM 14678667 ER PT J AU Keel, WC Borne, KD AF Keel, WC Borne, KD TI Massive star clusters in ongoing galaxy interactions: Clues to cluster formation SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 5752, NGC 5754, NGC 6621, NGC 6622); galaxies : interactions; galaxies : star clusters ID SPIRAL GALAXIES; LUMINOSITY FUNCTION; STELLAR PHOTOMETRY; DISK; WFPC2; ANTENNAE; REGIONS; PAIRS; TAILS AB We present HST WFPC2 observations, supplemented by ground-based Halpha data, of the star-cluster populations in two pairs of interacting galaxies selected for being in very different kinds of encounters seen at different stages. Dynamical information and n-body simulations provide the details of encounter geometry, mass ratio, and timing. In NGC 5752/4 we are seeing a weak encounter, well past closest approach, after about 2.5 x 10(8) yr. The large spiral NGC 5754 has a normal population of disk clusters, while the fainter companion NGC 5752 exhibits a rich population of luminous clusters with a flatter luminosity function. The strong, ongoing encounter in NGC 6621/2, seen about 1.0 x 10(8) yr past closest approach between roughly equal-mass galaxies, has produced an extensive population of luminous clusters, particularly young and luminous in a small region between the two nuclei. This region is dynamically interesting, with such a strong perturbation in the velocity field that the rotation curve reverses sign. From these results, in comparison with other strongly interacting systems discussed in the literature, cluster formation requires a threshold level of perturbation, with stage of the interaction a less important factor. The location of the most active star formation in NGC 6621/2 draws attention to a possible role for the Toomre stability threshold in shaping star formation in interacting galaxies. The rich cluster populations in NGC 5752 and NGC 6621 show that direct contact between gas-rich galaxy disks is not a requirement to form luminous clusters and that they can be triggered by processes happening within a single galaxy disk ( albeit triggered by external perturbations). C1 Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA. Raytheon Co, Inst Sci & Technol, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Keel, WC (reprint author), Univ Alabama, Dept Phys & Astron, Box 870324, Tuscaloosa, AL 35487 USA. OI Keel, William/0000-0002-6131-9539 NR 48 TC 16 Z9 17 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2003 VL 126 IS 3 BP 1257 EP 1275 DI 10.1086/377482 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 718EJ UT WOS:000185131900010 ER PT J AU Pritzl, BJ Smith, HA Stetson, PB Catelan, M Sweigart, AV Layden, AC Rich, RM AF Pritzl, BJ Smith, HA Stetson, PB Catelan, M Sweigart, AV Layden, AC Rich, RM TI Hubble Space Telescope snapshot study of variable stars in globular clusters: The inner region of NGC 6441 SO ASTRONOMICAL JOURNAL LA English DT Article DE globular clusters : individual (NGC 6441); RR Lyrae variable ID RR-LYRAE STARS; HORIZONTAL-BRANCH STARS; POPULATION-II CEPHEIDS; PERIOD-LUMINOSITY RELATION; AGE-METALLICITY RELATION; COLOR-MAGNITUDE DIAGRAM; METAL-RICH; GALACTIC HALO; 2ND-PARAMETER PHENOMENON; INTEGRATED LIGHT AB We present the results of a Hubble Space Telescope snapshot program to survey the inner region of the metal-rich globular cluster NGC 6441 for its variable stars. A total of 57 variable stars were found, including 38 RR Lyrae stars, six Population II Cepheids, and 12 long-period variables. Twenty-four of the RR Lyrae stars and all of the Population II Cepheids were previously undiscovered in ground-based surveys. Of the RR Lyrae stars observed in this survey, 26 are pulsating in the fundamental mode with a mean period of 0.753 days and 12 are first-overtone-mode pulsators with a mean period of 0.365 days. These values match up very well with those found in ground- based surveys. Combining all the available data for NGC 6441, we find mean periods of 0.759 and 0.375 days for the RRab and RRc stars, respectively. We also find that the RR Lyrae stars in this survey are located in the same regions of a period-amplitude diagram as those found in ground- based surveys. The overall ratio of RRc to total RR Lyrae stars is 0.33. Although NGC 6441 is a metal-rich globular cluster and would, on that ground, be expected either to have few RR Lyrae stars or to be an Oosterho. type I system, its RR Lyrae stars more closely resemble those in Oosterho. type II globular clusters. However, even compared with typical Oosterho. type II systems, the mean period of its RRab stars is unusually long. We also derived I-band period-luminosity relations for the RR Lyrae stars. Of the six Population II Cepheids, five are of W Virginis type and one is a BL Herculis variable star. This makes NGC 6441, along with NGC 6388, the most metal-rich globular cluster known to contain these types of variable stars. Another variable, V118, may also be a Population II Cepheid, given its long period and its separation in magnitude from the RR Lyrae stars. We examine the period-luminosity relation for these Population II Cepheids and compare it with those in other globular clusters and in the Large Magellanic Cloud. We argue that there does not appear to be a change in the period-luminosity relation slope between the BL Herculis and W Virginis stars, but that a change of slope does occur when the RV Tauri stars are added to the period-luminosity relation. C1 Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. Natl Res Council Canada, Herzberg Inst Astrophys, Dominion Astrophys Observ, Victoria, BC V9E 2E7, Canada. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago, Chile. NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Bowling Green State Univ, Dept Phys & Astron, Bowling Green, OH 43403 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Pritzl, BJ (reprint author), Natl Opt Astron Observ, POB 26732, Tucson, AZ 85726 USA. NR 93 TC 55 Z9 56 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2003 VL 126 IS 3 BP 1381 EP 1401 DI 10.1086/377024 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 718EJ UT WOS:000185131900019 ER PT J AU Chiar, JE Adamson, AJ Whittet, DCB Pendleton, YJ AF Chiar, J. E. Adamson, A. J. Whittet, D. C. B. Pendleton, Y. J. TI Spectroscopy of Hydrocarbon Grains toward the Galactic Center and Quintuplet Cluster SO ASTRONOMISCHE NACHRICHTEN LA English DT Article DE extinction; interstellar medium dust and molecules; circumstellar dust AB Our view of the Galactic center (GC) is affected by extinction from both diffuse interstellar medium (ISM) dust and dense molecular clouds along the line of sight. The enormous visual extinction present toward the center of our Galaxy (similar to 31 magnitudes) necessitates a study of the interstellar dust properties as well as an investigation into the distribution of the different dust components. We have built upon the historic spectroscopy of Willner et al. (1979), Butchart et al. (1986), and McFadzean et al. (1989) in order to investigate the distribution of these dust components across the GC field. Specifically, we employ spectroscopy in the 3 mu m region to investigate absorption features at 3.0 mu m and 3.4 mu m in lines of sight toward the GC central cluster and the Quintuplet cluster to the northeast. The 3.4 mu m feature is one of the primary spectral signatures of the organic component of interstellar dust and is, to date, only observed in the cold diffuse interstellar medium. The 3.0 mu m ice feature is carried by dense molecular cloud material, and can therefore be used to loosely trace the distribution of such material across the GC field. By obtaining spectra for multiple sightlines we have been able to deconvolve the diffuse ISM and dense molecular cloud components. Our study shows that differences exist in the spectra of relatively nearby lines of sight in the Galactic center central cluster. The depth of the 3.0 mu m water-ice feature varies by a factor of almost 5 across a 2 parsec (in projection) region, perhaps reflecting the clumpy nature of the dense clouds. In addition, we found that the 3.4 mu m hydrocarbon feature varies in depth across the areas studied toward the central cluster, whereas the depth is relatively constant toward the Quintuplet cluster. This is likely a reflection of the distribution of extinction from the foreground diffuse ISM. Our ground-based and space-based spectroscopy reveals differences in absorption features in the 3 and 6 mu m regions between sightlines toward the GC central cluster and those toward the Quintuplet cluster. While the 3 mu m spectra of both regions show a broad absorption feature blueward of the 3.4 mu m absorption, only the Quintuplet spectra show a distinct absorption feature at 3.28 mu m. This feature is indicative of the presence of polycyclic aromatic hydrocarbons (PAHs) along the line of sight. The Quintuplet-proper sources have 6 mu m spectra that are markedly different than that of GC IRS 7 in the central cluster, and instead strongly resemble the spectra seen toward dusty late-type carbon-class (WC) Wolf-Rayet stars. This is the first hint of some spectroscopic similarity between the Quintuplet sources and dusty WC stars. C1 [Chiar, J. E.; Pendleton, Y. J.] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Chiar, J. E.] SETI Inst, Mountain View, CA 94043 USA. [Adamson, A. J.] Joint Astron Ctr, Hilo, HI 96720 USA. [Whittet, D. C. B.] Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. RP Chiar, JE (reprint author), NASA, Ames Res Ctr, Mail Stop 245-3, Moffett Field, CA 94035 USA. EM chiar@misty.arc.nasa.gov OI Whittet, Douglas/0000-0001-8539-3891; adamson, andrew/0000-0003-1120-5178 NR 36 TC 0 Z9 0 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY SN 0004-6337 J9 ASTRON NACHR JI Astro. Nachr. PD SEP PY 2003 VL 324 SU 1 BP 109 EP 115 DI 10.1002/asna.200385056 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA V23UK UT WOS:000208367500016 ER PT J AU Novak, G Chuss, DT Dotson, JL Griffin, GS Loewenstein, RF Newcomb, MG Pernic, D Peterson, JB Renbarger, T AF Novak, G. Chuss, D. T. Dotson, J. L. Griffin, G. S. Loewenstein, R. F. Newcomb, M. G. Pernic, D. Peterson, J. B. Renbarger, T. TI Observation of Toroidal Magnetic Fields on 100 pc Scales in the Galactic Center SO ASTRONOMISCHE NACHRICHTEN LA English DT Article DE Magnetic Fields; Galactic Center; Submillimeter Polarimetry; Interstellar Dust AB We present new submillimeter polarimetric observations of the Galactic center region, made using the SPARO polarimeter that operates at the South Pole. Compared with previous submillimeter polarimetry of this region, our measurements cover much more sky area, and they imply that the molecular gas in the central few hundred pc is threaded by a large scale toroidal magnetic field. We consider this result together with radio observations that show evidence for poloidal fields in the Galactic center, and with Faraday rotation observations. We compare all of these observations with a magnetodynamic model for the Galactic center. C1 [Novak, G.] Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. [Chuss, D. T.] NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. [Dotson, J. L.] NASA, Ames Res Ctr, Washington, DC USA. [Griffin, G. S.; Peterson, J. B.] Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. [Loewenstein, R. F.; Newcomb, M. G.; Pernic, D.] Univ Chicago, Yerkes Observ, Chicago, IL 60637 USA. [Renbarger, T.] Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. RP Novak, G (reprint author), Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. EM g-novak@northwestern.edu NR 11 TC 0 Z9 0 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY SN 0004-6337 J9 ASTRON NACHR JI Astro. Nachr. PD SEP PY 2003 VL 324 SU 1 BP 133 EP 137 DI 10.1002/asna.200385078 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA V23UK UT WOS:000208367500019 ER PT J AU Chuss, DT Novak, G Davidson, JA Dotson, JL Dowell, CD Hildebrand, RH Vaillancourt, JE AF Chuss, David T. Novak, Giles Davidson, Jacqueline A. Dotson, Jessie L. Dowell, C. Darren Hildebrand, Roger H. Vaillancourt, John E. TI Mapping Magnetic Fields in the Cold Dust at the Galactic Center SO ASTRONOMISCHE NACHRICHTEN LA English DT Article DE Magnetic Fields; Galactic Center; Submillimeter Polarimetry; Dust AB We report the measurement of 158 new 350 mu m polarimetry vectors in the central 30 parsecs of the Galactic center. These data were obtained at the Caltech Submillimeter Observatory using Hertz. Morphologically, these results show a consistency with previously published far-infrared and submillimeter results. We find that the angle of the magnetic field inferred from these observations is related to the 350 mu m flux as obtained by SHARC/CSO in the following way. At low fluxes, the magnetic field angle is consistent with that of a poloidal field as seen in nearby features such as the Galactic Center Radio Arc and the Northern and Southern Threads. At high fluxes, the magnetic field is oriented parallel to the plane of the Galaxy. This relationship suggests a model in which an initially poloidal field is sheared out in dense regions which are dominated by gravity. If this model is correct, it implies a characteristic field strength for the region of 3 mG. C1 [Chuss, David T.] NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. [Novak, Giles] Northwestern Univ, Evanston, IL 60208 USA. [Dotson, Jessie L.] NASA, Ames Res Ctr, Washington, DC USA. [Dowell, C. Darren] CALTECH, Pasadena, CA 91125 USA. [Hildebrand, Roger H.] Univ Chicago, Chicago, IL 60637 USA. [Vaillancourt, John E.] Univ Wisconsin, Madison, WI 53706 USA. RP Chuss, DT (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM chuss@stars.gsfc.nasa.gov NR 16 TC 1 Z9 1 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY SN 0004-6337 J9 ASTRON NACHR JI Astro. Nachr. PD SEP PY 2003 VL 324 SU 1 BP 173 EP 179 DI 10.1002/asna.200385099 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA V23UK UT WOS:000208367500026 ER PT J AU Maeda, Y Itoh, K Baganoff, FK Bautz, MW Brandt, WN Burrows, DN Doty, JP Feigelson, ED Garmire, GP Morris, M Muno, MP Park, S Pravdo, SH Ricker, GR Townsley, LK AF Maeda, Y. Itoh, K. Baganoff, F. K. Bautz, M. W. Brandt, W. N. Burrows, D. N. Doty, J. P. Feigelson, E. D. Garmire, G. P. Morris, M. Muno, M. P. Park, S. Pravdo, S. H. Ricker, G. R. Townsley, L. K. TI Chandra ACIS Imaging Spectroscopy of Sgr A East SO ASTRONOMISCHE NACHRICHTEN LA English DT Article DE Galaxy: center; ISM: clouds; X-rays: individual (Sagittarius A East); X-rays: ISM AB We report on the X-ray emission from the shell-like, non-thermal radio source Sgr A East located in the inner few parsecs of the Galaxy based on observations made with the ACIS detector on board the Chandra X-ray Observatory. The X-ray emission from Sgr A East is concentrated within the central similar or equal to 2 pc of the larger radio shell. The spectrum shows strong K alpha lines from highly ionized ions of S, Ar, Ca, and Fe. A simple isothermal plasma model gives electron temperature similar to 2 keV, absorption column similar to 1 x 10(23) H cm(-2) luminosity similar to 8 x 10(34) ergs s(-1) in the 2-10 keV band, and gas mass similar to 2n1/2 M-circle dot with a filling factor n. The plasma appears to be rich in heavy elements, over-abundant by roughly a factor of four with respect to solar abundances. Accompanied with filamentary or blob-like structures, the plasma shows a spatial gradient of elemental abundance: the spatial distribution of iron is more compact than that of the lighter elements. These Chandra results strongly support the long-standing hypothesis that Sgr A East is a supernova remnant (SNR). Since Sgr A East surrounds Sgr A* in projection, it is possible that the dust ridge compressed by the forward shock of Sgr A East hit Sgr A* in the past, and the passage of the ridge may have supplied material to accrete onto the black hole in the past, and may have removed material from the black hole vicinity, leading to its present quiescent state. C1 [Maeda, Y.; Itoh, K.] Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Sagamihara, Kanagawa 2298510, Japan. [Baganoff, F. K.; Bautz, M. W.; Doty, J. P.; Muno, M. P.; Ricker, G. R.] MIT, Ctr Space Res, Cambridge, MA 02139 USA. [Brandt, W. N.; Burrows, D. N.; Feigelson, E. D.; Garmire, G. P.; Park, S.; Townsley, L. K.] Penn State Univ, Davey Lab 525, University Pk, PA 16802 USA. [Morris, M.] Univ Calif Los Angeles, Los Angeles, CA 90095 USA. [Pravdo, S. H.] CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Maeda, Y (reprint author), Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 2298510, Japan. EM ymaeda@astro.isas.ac.jp RI Brandt, William/N-2844-2015 OI Brandt, William/0000-0002-0167-2453 NR 10 TC 0 Z9 0 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY SN 0004-6337 J9 ASTRON NACHR JI Astro. Nachr. PD SEP PY 2003 VL 324 SU 1 BP 205 EP 210 DI 10.1002/asna.200385107 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA V23UK UT WOS:000208367500030 ER PT J AU Adamson, A Mason, R Macdonald, E Wright, G Chiar, J Pendleton, Y Kerr, T Bowey, J Whittet, D Rawlings, M AF Adamson, Andy Mason, Rachel Macdonald, Emily Wright, Gillian Chiar, Jean Pendleton, Yvonne Kerr, Tom Bowey, Janet Whittet, Doug Rawlings, Mark TI A Census of Dust Absorption at the Galactic Centre SO ASTRONOMISCHE NACHRICHTEN LA English DT Article DE Interstellar: dust; molecules; extinction AB The Galactic Centre offers a uniquely valuable line of sight for studies of the nature of dust in the ISM, but the long-held assumption that the line of sight samples only the diffuse ISM has been subverted by ground-based and ISO observations demonstrating the presence of absorption bands due to solid-phase volatile ices in the field. Spatial variability of the observed features suggests a patchy distribution of even the foreground diffuse-medium absorption. To map this clumpy distribution and to produce an inventory of the dust components, we are carrying out a narrow-band imaging survey over a field which extends from the Galactic Centre to beyond the circumnuclear ring, using both IRCAM3 and Michelle on UKIRT to cover the 3 mu m water ice, 3.3 mu m PAH, 3.4 mu m hydrocarbon and 9.7 mu m silicate absorption features. This paper presents the rationale for this programme and reports on progress with analysis of the survey data. C1 [Adamson, Andy; Kerr, Tom] Joint Astron Ctr, Hilo, HI 96720 USA. [Mason, Rachel; Wright, Gillian] Royal Observ, Edinburgh EH9 3HJ, Midlothian, Scotland. [Macdonald, Emily] Univ Oxford, Dept Astrophys, Oxford OX1 3RH, England. [Chiar, Jean; Pendleton, Yvonne] NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. [Bowey, Janet] UCL, Dept Phys & Astron, London WC1E 6BT, England. [Whittet, Doug] Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. [Rawlings, Mark] Univ Helsinki, FIN-00014 Helsinki, Finland. RP Adamson, A (reprint author), Joint Astron Ctr, 665 Komohana St, Hilo, HI 96720 USA. EM a.adamson@jach.hawaii.edu OI Whittet, Douglas/0000-0001-8539-3891 NR 15 TC 0 Z9 0 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY SN 0004-6337 J9 ASTRON NACHR JI Astro. Nachr. PD SEP PY 2003 VL 324 SU 1 BP 211 EP 215 DI 10.1002/asna.200385097 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA V23UK UT WOS:000208367500031 ER PT J AU Blum, RD Ramirez, SV Sellgren, K Olsen, K AF Blum, Robert D. Ramirez, Solange V. Sellgren, Kristen Olsen, Knut TI Really Cool Stars and the Star Formation History at the Galactic Center SO ASTRONOMISCHE NACHRICHTEN LA English DT Article DE Galactic Center; AGB Stars; Star Formation AB We present lambda/Delta lambda = 550 to 1200 near infrared H and K spectra for a magnitude limited sample of 79 asymptotic giant branch and cool supergiant stars in the central approximate to 5 pc (diameter) of the Galaxy. Using a set of similar spectra obtained for solar neighborhood stars with the same range in T-eff and M-bol for the Galactic center (GC) sample as calibrators, we construct the Hertzsprung-Russell diagram for the GC sample. Using an automated maximum likelihood routine, we derive a coarse star formation history of the GC. We find that roughly 75 % of the stars that have formed in the central few pc are older than 5 Gyr. In particular, the best fitting star formation history yields star formation rates in four age bins of 0.01 to 0.10 Gyr, 0.10 to 1.0 Gyr, 1.0 to 5.0 Gyr, and 5 Gyr to 12 Gyr, of 39.5 +/- 11 x 10(-4) M-circle dot yr(-1), 3.6 +/- 2 x 10(-4) M-circle dot yr(-1), 5.7 +/- 2 x 10(-4) M-circle dot yr(-1) , and 13.4 +/- 5 x 10(-4) M-circle dot yr(-1), respectively. The GC has been forming stars over the last 100 Myr at a rate roughly four times higher than the average rate over 12 Gyr, though the total mass formed in this recent epoch is less than three percent of the total mass formed over all times. C1 [Blum, Robert D.; Olsen, Knut] Cerro Tololo Interamer Observ, La Serena, Chile. [Ramirez, Solange V.] CALTECH, JPL, SIRTF Sci Ctr, Pasadena, CA 91125 USA. [Sellgren, Kristen] Ohio State Univ, Dept Astron, Columbus, OH 43210 USA. RP Blum, RD (reprint author), Cerro Tololo Interamer Observ, Cassila 603, La Serena, Chile. EM rblum@ctio.noao.edu; solange@astro.caltech.edu; sellgren@astronomy.ohio-state.edu; kolsen@ctio.noao.edu NR 33 TC 0 Z9 0 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY SN 0004-6337 J9 ASTRON NACHR JI Astro. Nachr. PD SEP PY 2003 VL 324 SU 1 BP 247 EP 253 DI 10.1002/asna.200385054 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA V23UK UT WOS:000208367500037 ER PT J AU Gezari, D Dwek, E Varosi, F AF Gezari, Dan Dwek, Eli Varosi, Frank TI Physical Conditions in the Central Parsec Modeled from Mid-Infrared Imaging Photometry SO ASTRONOMISCHE NACHRICHTEN LA English DT Article DE infrared; imaging; galactic center AB We have made array camera images of the central parsec with 1 arcsec resolution at eight mid-infrared wavelengths between 4.8 and 20.0 mu m. The images are used to model the temperature, opacity and bolometric luminosity distributions of the emitting dust in the central parsec, as well as the dust extinction in the line of sight. Several new results emerge from the model calculations: 1) The compact IRS sources are all local peaks in the emitting dust temperature distribution. 2) The IRS source positions are local minima in the emitting dust opacity distribution. 3) The opacity and temperature distributions are generally complementary. 4) The compact IRS sources are very luminous, particularly the IRS3 and IRS1 (L similar to 3x10(5) L-circle dot), and they make a significant contribution to the energy budget of infrared complex. C1 [Gezari, Dan; Dwek, Eli] NASA, Goddard Space Flight Ctr, Infrared Astrophys Branch, Greenbelt, MD 20771 USA. [Varosi, Frank] Univ Florida, Dept Astron, Gainesville, FL 32611 USA. RP Gezari, D (reprint author), NASA, Goddard Space Flight Ctr, Infrared Astrophys Branch, Code 685, Greenbelt, MD 20771 USA. EM gezari@stars.gsfc.nasa.gov NR 10 TC 0 Z9 0 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY SN 0004-6337 J9 ASTRON NACHR JI Astro. Nachr. PD SEP PY 2003 VL 324 SU 1 BP 573 EP 576 DI 10.1002/asna.200385102 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA V23UK UT WOS:000208367500086 ER PT J AU Porquet, D Reeves, JN AF Porquet, D Reeves, JN TI An intense and broad FeK alpha line observed in the X-ray luminous quasar Q0056-363 with XMM-Newton SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : active; X-rays : galaxies; accretion discs; quasars : individual : Q0056-363 ID BLACK-HOLE; GRATING SPECTROMETER; SEYFERT-1 GALAXIES; ACCRETION DISKS; EMISSION-LINE; IRON LINE; MCG-6-30-15; REFLECTION; SAMPLE; ENERGY AB We present an XMM-Newton observation of the radio-quiet quasar Q0056-363 (z = 0.162). This is the first time that this quasar is observed in the hard X-ray range (above 2 keV). We find that Q0056-363 is a powerful X-ray quasar, with a 0.3-12 keV unabsorbed luminosity of about 1.2 x 10(45) erg s(-1) with the largest part (similar to67%) emitted below 2 keV. The spectrum reveals a large featureless soft X-ray excess below 2 keV and a strong broad FeKalpha line at 6.4 keV (in the quasar frame). The FeKalpha line is due to low to moderate ionization states of iron (i.e., < Fe X VII), with an equivalent width of about 250 eV and a velocity width of about 25 000 km s(-1). Q0056-363 is presently the most luminous AGN known to exhibit such a broad and intense FeKα line profile from near neutral iron. The line can be fitted with a relativistic profile from an accretion disc around either a Schwarzschild (non-rotating) or a Kerr (rotating) black hole. A combination of two thermal Comptonization components and a disc reflection model is favored to explain both the continuum over the energy range 0.3-12 keV and the FeKα line. A patchy corona covering a large part of the inner disc surface is needed in order to be compatible with the accretion rate inferred from the spectral energy distribution of Q0056-363, unless the mass of the black hole is much higher than about 5 x 10(8) M.. 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, Columbia, MD 21044 USA. RP Porquet, D (reprint author), Max Planck Inst Extraterr Phys, Postfach 1312, D-85741 Garching, Germany. NR 43 TC 16 Z9 16 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2003 VL 408 IS 1 BP 119 EP 125 DI 10.1051/0004-6361:20030950 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 715ZX UT WOS:000185005300016 ER PT J AU Richard, D AF Richard, D TI On non-linear hydrodynamic instability and enhanced transport in differentially rotating flows SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE hydrodynamics; instabilities; turbulence ID ACCRETION DISKS; TURBULENCE; VISCOSITY; STABILITY AB In this paper we argue that differential rotation can possibly sustain hydrodynamic turbulence in the absence of a magnetic field. We explain why the non-linearities of the hydrodynamic equations (i.e. turbulent diffusion) should not be neglected, either as a simplifying approximation or based on boundary counditions (Hawley et al. 1999). The consequences of lifting this hypothesis are studied for the flow stability and the enhanced turbulent transport. We develop a simple general model for the energetics of turbulent fluctuations in differentially rotating flows. By taking into account the non-linearities of the equations of motions, we give constraints on the mean flow properties for the possible development of shear instability. The results from recent laboratory experiments on rotating flows show - in agreement with the model - that the pertinent parameter for stability appears to be the Rossby number Ro. The laboratory experiments seem to be compatible with Ro < -1/2 and Ro > 1 in the inviscid or high rotation rates limit. Our results, taken in the inviscid limit, are coherent with the classical linear stability analysis, in the sense that the critical perturbation equals zero on the marginal linear stability curve. We also propose a prescription for turbulent viscosity which generalize the beta-prescription derived in Richard Zahn (1999). C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Observ Paris, LUTH, F-92190 Meudon, France. CEA, GIT, SPEC, F-91190 Gif Sur Yvette, France. RP Richard, D (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. NR 19 TC 18 Z9 18 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2003 VL 408 IS 2 BP 409 EP U2 DI 10.1051/0004-6361:20031010 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 716AM UT WOS:000185006700002 ER PT J AU Valesecchi, GB Milani, A Gronchi, GF Chesley, SR AF Valesecchi, GB Milani, A Gronchi, GF Chesley, SR TI Resonant returns to close approaches: Analytical theory SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE minor planets, asteroids; Solar system : general ID ASTEROID IDENTIFICATION PROBLEM; ENCOUNTERS; PERTURBATIONS; EARTH AB We extend Opik's theory of close encounters of a small body (either an asteroid or a comet) by explicitly introducing the nodal distance and a time coordinate. Assuming that the heliocentric motion between consecutive close encounters is Keplerian, or given by an explicit propagator, we can compute the initial conditions for an encounter as functions of the outcomes of a previous one; in this way it is possible to obtain a completely analytical theory of resonant returns. It is found that the initial conditions of a close encounter that lead to a resonant return must lie close to easily computable circles on the b-plane of the first encounter. By further assuming that the nodal distance varies uniformly with time, due to secular perturbations, and considering the derivatives of the coordinates on the b-plane of the second encounter with respect to those on the b-plane of the first encounter, we compute in the latter the location, shape and size of collision keyholes. C1 Ist Astrofis Spaziale & Fis Cosm, I-00133 Rome, Italy. Univ Pisa, Dipartimento Matemat, I-56127 Pisa, Italy. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Ist Astrofis Spaziale & Fis Cosm, Via Fosso Cavaliere 100, I-00133 Rome, Italy. EM giovanni@rm.iasf.cnr.it; milani@dm.unipi.it; gronchi@dm.unipi.it; steve.chesley@jpl.nasa.gov OI Valsecchi, Giovanni/0000-0002-2915-1465 NR 23 TC 56 Z9 59 U1 0 U2 1 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2003 VL 408 IS 3 BP 1179 EP + DI 10.1051/0004-6361:20031039 PG 28 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 719PQ UT WOS:000185212600037 ER PT J AU Kudrya, YN Karachentseva, VE Karachentsev, ID Mitronova, SN Jarrett, TH Huchtmeier, WK AF Kudrya, YN Karachentseva, VE Karachentsev, ID Mitronova, SN Jarrett, TH Huchtmeier, WK TI The bulk motion of flat edge-on galaxies based on 2MASS photometry SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : spiral; galaxies : fundamental parameters ID TULLY-FISHER RELATION; VELOCITY-WIDTH RELATION; PECULIAR VELOCITIES; ROTATION CURVES; DISTANCE SCALE; SPIRAL GALAXIES; SKY SURVEY; CLUSTER; CATALOG; FIELD AB We report the results of applying the 2MASS Tully-Fisher (TF) relations to study galaxy bulk flows. For 1141 all-sky distributed flat RFGC galaxies we construct J, H, K-s TF relations and find that Kron J(fe) magnitudes show the smallest dispersion on the TF diagram. For the sample of 971 RFGC galaxies with V-3K<18000 km s(-1) we find a dispersion σ(TF)=0.42(m) and an amplitude of bulk flow V=199&PLUSMN;61 km s(-1), directed towards l=301&DEG;&PLUSMN;18&DEG;, b=-2&DEG;&PLUSMN;15&DEG;. Our determination of low-amplitude coherent flow is in good agreement with a set of recent data derived from EFAR, PSCz and SCI/SCII samples. The resultant two-dimensional smoothed peculiar velocity field traces well the large-scale density variations in the galaxy distributions. The regions of large positive peculiar velocities lie in the direction of the Great Attractor and Shapley concentration. A significant negative peculiar velocity is seen in the direction of Bootes and in the direction of the Local void. A small positive peculiar velocity (100-150 km s(-1)) is seen towards the Pisces-Perseus supercluster, as well as the Hercules-Coma-Corona Borealis supercluster regions. C1 Russian Acad Sci, Special Astrophys Observ, N Arkhyz 369167, KChR, Russia. Taras Shevchenko Natl Univ, Astron Observ Kiev, UA-04053 Kiev, Ukraine. CALTECH, Ctr Infrared Proc & Anal, Jet Propuls Lab, Pasadena, CA 91125 USA. Max Planck Inst Radioastron, D-53121 Bonn, Germany. Isaac Newton Inst Chile, SAO Branch, St Petersburg, Russia. RP Mitronova, SN (reprint author), Russian Acad Sci, Special Astrophys Observ, N Arkhyz 369167, KChR, Russia. NR 42 TC 16 Z9 18 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2003 VL 407 IS 3 BP 889 EP 898 DI 10.1051/0004-6361:20030857 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 710FD UT WOS:000184669400015 ER PT J AU Jean, P Nnodlseder, J Lonjou, V Allain, M Roques, JP Skinner, GK Teegarden, BJ Vedrenne, G von Ballmoos, P Cordier, B Caraveo, P Diehl, R Durouchoux, P Mandrou, P Matteson, J Gehrels, N Schonfelder, V Strong, AW Ubertini, P Weidenspointner, G Winkler, C AF Jean, P Nnodlseder, J Lonjou, V Allain, M Roques, JP Skinner, GK Teegarden, BJ Vedrenne, G von Ballmoos, P Cordier, B Caraveo, P Diehl, R Durouchoux, P Mandrou, P Matteson, J Gehrels, N Schonfelder, V Strong, AW Ubertini, P Weidenspointner, G Winkler, C TI Early SPI/INTEGRAL measurements of 511 keV line emission from the 4th quadrant of the Galaxy SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma rays : observations; line : profiles; Galaxy : center ID GALACTIC-CENTER REGION; POSITRON-ANNIHILATION RADIATION; CENTER DIRECTION; SPECTRUM; SPECTROMETER AB We report the first measurements of the 511 keV line emission from the Galactic Centre (GC) region performed with the spectrometer SPI on the space observatory INTEGRAL (International Gamma-Ray Astrophysics Laboratory). Taking into account the range of spatial distribution models which are consistent with the data, we derive a flux of 9.9(-2.1)(+4.7) x 10(-4) ph cm(-2) s(-1) and an intrinsic line width of 2.95(-0.51)(+0.45) keV (FWHM). The results are consistent with other high-spectroscopy measurements, though the width is found to be at the upper bound of previously reported values. C1 Univ Toulouse 3, CESR, CNRS, F-31028 Toulouse 4, France. NASA, LHEA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. ESA, Estec, RSSD, NL-2201 AZ Noordwijk, Netherlands. CNR, IAS, I-00133 Rome, Italy. CEA Saclay, DSM, DAPNIA, SAp, F-91191 Gif Sur Yvette, France. Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. CNR G Occhialini, IFC, I-20133 Milan, Italy. RP Jean, P (reprint author), Univ Toulouse 3, CESR, CNRS, BP 4346, F-31028 Toulouse 4, France. RI Gehrels, Neil/D-2971-2012 NR 19 TC 225 Z9 228 U1 0 U2 2 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD SEP PY 2003 VL 407 IS 3 BP L55 EP L58 DI 10.1051/0004-6361:20031056 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 710FD UT WOS:000184669400003 ER PT J AU Crenshaw, DM Kraemer, SB Gabel, JR Kaastra, JS Steenbrugge, KC Brinkman, AC Dunn, JP George, IM Liedahl, DA Paerels, FBS Turner, TJ Yaqoob, T AF Crenshaw, DM Kraemer, SB Gabel, JR Kaastra, JS Steenbrugge, KC Brinkman, AC Dunn, JP George, IM Liedahl, DA Paerels, FBS Turner, TJ Yaqoob, T TI Simultaneous ultraviolet and X-ray spectroscopy of the Seyfert 1 galaxy NGC 5548. I. Physical conditions in the ultraviolet absorbers SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : individual (NGC 5548); galaxies : Seyfert; ultraviolet : galaxies ID ACTIVE GALACTIC NUCLEI; INTRINSIC ABSORPTION-LINES; IONIZED-GAS; EXPLORER OBSERVATIONS; GRATING SPECTROSCOPY; SPACE-TELESCOPE; SPECTRA; CHANDRA; REGION; NGC-3783 AB We present new UV spectra of the nucleus of the Seyfert 1 galaxy NGC 5548, which we obtained with the Space Telescope Imaging Spectrograph at high spectral resolution, in conjunction with simultaneous Chandra X-Ray Observatory spectra. Taking advantage of the low UV continuum and broad emission-line fluxes, we have determined that the deepest UV absorption component covers at least a portion of the inner, high-ionization narrow-line region (NLR). We find nonunity covering factors in the cores of several kinematic components, which increase the column density measurements of N v and C iv by factors of 1.2 - 1.9 over the full-covering case; however, the revised columns have only a minor effect on the parameters derived from our photoionization models. For the first time, we have simultaneous N v and C iv columns for component 1 ( at - 1040 km s(-1)) and find that this component cannot be an X-ray warm absorber, contrary to our previous claim based on nonsimultaneous observations. We find that models of the absorbers based on solar abundances severely overpredict the O vi columns previously obtained with the Far Ultraviolet Spectroscopic Explorer and present arguments that this is not likely due to variability. However, models that include either enhanced nitrogen ( twice solar) or dust, with strong depletion of carbon in either case, are successful in matching all of the observed ionic columns. These models result in substantially lower ionization parameters and total column densities compared to dust-free solar-abundance models and produce little O VII or O VIII, indicating that none of the UV absorbers are X-ray warm absorbers. C1 Georgia State Univ, Dept Phys & Astron, Astron Off, Atlanta, GA 30303 USA. Catholic Univ Amer, Greenbelt, MD 20771 USA. NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. SRON, Natl Inst Space Res, NL-3584 CA Utrecht, Netherlands. Univ Maryland Baltimore Cty, Joint Ctr Astrophys, Baltimore, MD 21250 USA. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Lawrence Livermore Natl Lab, Dept Phys, Livermore, CA 94550 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. RP Crenshaw, DM (reprint author), Georgia State Univ, Dept Phys & Astron, Astron Off, 1 Pk Pl S SE,Suite 700, Atlanta, GA 30303 USA. NR 39 TC 43 Z9 43 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2003 VL 594 IS 1 BP 116 EP 127 DI 10.1086/376792 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 717KJ UT WOS:000185087400010 ER PT J AU Turner, TJ Kraemer, SB Mushotzky, RF George, IM Gabel, JR AF Turner, TJ Kraemer, SB Mushotzky, RF George, IM Gabel, JR TI Elemental abundances in NGC 3516 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : abundances; galaxies : active; galaxies : individual (NGC 3516); galaxies : nuclei; galaxies : Seyfert ID NARROW-LINE REGION; REFLECTION GRATING SPECTROMETER; HELIUM-LIKE IONS; WARM ABSORBER; XMM-NEWTON; PHYSICAL CONDITIONS; GALAXY NGC-3516; EMISSION-LINES; NGC 3516; ABSORPTION AB We present Reflection Grating Spectrometer data from an XMM-Newton observation of the Seyfert 1 galaxy NGC 3516, taken while the continuum source was in an extremely low flux state. This observation offers a rare opportunity for a detailed study of emission from a Seyfert 1 galaxy, as these are usually dominated by high nuclear continuum levels and heavy absorption. The spectrum shows numerous narrow emission lines (FWHM less than or similar to 1300 km s(-1)) in the 0.3 - 2 keV range, including the H-like lines of C, N, and O and the He-like lines of N, O, and Ne. The emission-line ratios and the narrow width of the radiative recombination continuum of C vi indicate that the gas is photoionized and of fairly low temperature (kT less than or similar to 0.01 keV). The availability of emission lines from different elements for two isoelectronic sequences allows us to constrain the element abundances. These data show that the N lines are far stronger than would be expected from gas of solar abundances. Based on our photoionization models, we find that nitrogen is overabundant in the central regions of the galaxy, compared to carbon, oxygen, and neon, by at least a factor of 2.5. We suggest that this is the result of secondary production of nitrogen in intermediate-mass stars and indicative of the history of star formation in NGC 3516. C1 Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Catholic Univ Amer, NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Turner, TJ (reprint author), Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, 1000 Hilltop Circle, Baltimore, MD 21250 USA. NR 32 TC 15 Z9 15 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2003 VL 594 IS 1 BP 128 EP 135 DI 10.1086/376901 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 717KJ UT WOS:000185087400011 ER PT J AU Mukai, K Still, M Ringwald, FA AF Mukai, K Still, M Ringwald, FA TI The origin of soft X-rays in DQ herculis SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : eclipsing; novae, cataclysmic variables; stars : individual (DQ Herculis); X-rays : stars ID NOVA OY CARINAE; CATACLYSMIC VARIABLES; ACCRETION DISKS; CLASSICAL NOVAE; SUPEROUTBURST; BINARY; STARS; SPECTROSCOPY; OSCILLATION; QUIESCENCE AB DQ Herculis (Nova Herculis 1934) is a deeply eclipsing cataclysmic variable containing a magnetic white dwarf primary. The accretion disk is thought to block our line of sight to the white dwarf at all orbital phases because of its extreme inclination angle. Nevertheless, soft X-rays were detected from DQ Her with the ROSAT PSPC. To probe the origin of these soft X-rays, we have performed Chandra ACIS observations. We confirm that DQ Her is an X-ray source. The bulk of the X-rays are from a pointlike source and exhibit a shallow partial eclipse. We interpret this as being due to scattering of the unseen central X-ray source, probably in an accretion disk wind. At the same time, we observe what appear to be weak extended X-ray features around DQ Her, which we interpret as an X-ray-emitting knot in the nova shell. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Calif State Univ Fresno, Dept Phys, Fresno, CA 93740 USA. RP Mukai, K (reprint author), Columbia Univ, Columbia Astrophys Lab, 550 W 120th St, New York, NY 10027 USA. NR 36 TC 17 Z9 17 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2003 VL 594 IS 1 BP 428 EP 434 DI 10.1086/376752 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 717KJ UT WOS:000185087400033 ER PT J AU Orio, M Hartmann, W Still, M Greiner, J AF Orio, M Hartmann, W Still, M Greiner, J TI An XMM-Newton observation of Nova LMC 1995: A bright supersoft X-ray source SO ASTROPHYSICAL JOURNAL LA English DT Article DE novae,cataclysmic variables; stars : individual (Nova LMC 1995); X-rays : stars ID BLANKETED MODEL ATMOSPHERES; CLASSICAL NOVAE; WHITE-DWARFS; HOT STARS; EMISSION; EVOLUTION; OUTBURST; J0925.7-4758; BEPPOSAX; DECLINE AB Nova LMC 1995, previously detected during 1995-1998 with ROSAT, was observed again as a luminous supersoft X-ray source with XMM-Newton in 2000 December. This nova offers the possibility to observe the spectrum of a hot white dwarf, burning hydrogen in a shell and not obscured by a wind or nebular emission as in other supersoft X-ray sources. Notwithstanding uncertainties in the calibration of the European Photon Imaging Camera (EPIC) instruments at energy E < 0.5 keV, using atmospheric models in nonlocal thermonuclear equilibrium we derived an effective temperature in the range 400,000-450,000 K, a bolometric luminosity L-bol similar or equal to 2.3 x 10(37) ergs s(-1), and verified that the abundance of carbon is not significantly enhanced in the X-ray's emitting shell. The reflection grating spectrometer's grating spectra do not show emission lines ( originated in a nebula or a wind) observed for some other supersoft X-ray sources. The crowded atmospheric absorption lines of the white dwarf cannot be resolved. There is no hard component (expected from a wind, a surrounding nebula, or an accretion disk), with no counts above the background at E > 0.6 keV and an upper limit F-X,F-hard = 10(-14) ergs s(-)(1) cm(-2) to the X-ray flux above this energy. The background-corrected count rate measured by the EPIC instruments was variable on timescales of minutes and hours but without the flares or sudden obscuration observed for other novae. The power spectrum shows a peak at 5.25 hr, possibly because of a modulation with the orbital period. We also briefly discuss the scenarios in which this nova may become a Type Ia supernova progenitor. C1 INAF Turin Astron Observ, I-10025 Pino Torinese, Italy. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. SRON, Space Res Lab, NL-3584 Utrecht, Netherlands. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Space Res Assoc, Columbia, MD USA. Max Planck Inst Extraterr Phys, D-37075 Garching, Germany. RP INAF Turin Astron Observ, Strada Osservatorio 20, I-10025 Pino Torinese, Italy. EM orio@cow.physics.wisc.edu NR 41 TC 21 Z9 21 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 SEP 1 PY 2003 VL 594 IS 1 BP 435 EP 442 DI 10.1086/376828 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 717KJ UT WOS:000185087400034 ER PT J AU Gansicke, BT Szkody, P De Martino, D Beuermann, K Long, KS Sion, EM Knigge, C Marsh, T Hubeny, I AF Gansicke, BT Szkody, P De Martino, D Beuermann, K Long, KS Sion, EM Knigge, C Marsh, T Hubeny, I TI Anomalous ultraviolet line flux ratios in the cataclysmic variables 1RXS J232953.9+062814, CE 315, BZ Ursae Majoris, and EY Cygni, observed with the Hubble Space Telescope space telescope imaging spectrograph SO ASTROPHYSICAL JOURNAL LA English DT Article DE line : formation; novae, cataclysmic variables; stars : individual (1RXS J232953.9+062814, BZ Ursae Majoris, CE 315, EY Cygni) white dwarfs ID DWARF NOVA; CHEMICAL EVOLUTION; IUE OBSERVATIONS; SECONDARY STARS; ORBITAL PERIOD; UV SPECTRUM; WHITE-DWARF; BINARIES; SPECTROSCOPY; OUTBURSTS AB Brief Hubble Space Telescope Space Telescope Imaging Spectrograph spectroscopic snapshot exposures of the cataclysmic variables 1RXS J232953.9+062814, CE 315, BZ UMa, and EY Cyg reveal very large N v/C IV line flux ratios, similar to those observed in AE Aqr. Such anomalous line flux ratios have so far been observed in 10 systems and presumably reflect a different composition of the accreted material compared to the majority of cataclysmic variables. We discuss the properties of this small sample in the context of the recent proposal by Schenker et al. that a significant fraction of the present-day population of cataclysmic variables may have passed through a phase of thermal timescale mass transfer. C1 Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. Univ Washington, Dept Astron, Seattle, WA 98195 USA. Osservatorio Capodimonte, I-80131 Naples, Italy. Univ Sternwarte, D-37083 Gottingen, Germany. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Villanova Univ, Dept Astron & Astrophys, Villanova, PA 19085 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20711 USA. RP Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England. EM btg@astro.soton.ac.uk; szkody@astro.washington.edu; demartino@astrna.na.astro.it; beuermann@uni-sw.gwdg.de; long@stsci.edu; emsion@ast.villanova.edu; christian@astro.soton.ac.uk; trm@astro.soton.ac.uk; hubeny@tlusty.gsfc.nasa.gov RI Gaensicke, Boris/A-9421-2012; OI Gaensicke, Boris/0000-0002-2761-3005; de Martino, Domitilla/0000-0002-5069-4202 NR 30 TC 72 Z9 72 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 SEP 1 PY 2003 VL 594 IS 1 BP 443 EP 448 DI 10.1086/376902 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 717KJ UT WOS:000185087400035 ER PT J AU Sloan, GC Kraemer, KE Goebel, JH Price, SD AF Sloan, GC Kraemer, KE Goebel, JH Price, SD TI Guilt by association: The 13 micron dust emission feature and its correlation to other gas and dust features SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; dust, extinction; infrared : stars; stars : AGB and post-AGB ID CRYSTALLINE SILICATE DUST; ASYMPTOTIC GIANT BRANCH; RICH CIRCUMSTELLAR DUST; LOW-RESOLUTION SPECTRA; SOUTH-GALACTIC-CAP; ISO-SWS SPECTRA; MU-M FEATURE; SEMIREGULAR VARIABLES; EVOLVED STARS; AGB STARS AB A study of all full-scan spectra of optically thin oxygen-rich circumstellar dust shells in the database produced by the Short Wavelength Spectrometer on ISO reveals that the strength of several infrared spectral features correlates with the strength of the 13 mum dust feature. These correlated features include dust features at 19.8 and 28.1 mum and the bands produced by warm carbon dioxide molecules (the strongest of which are at 13.9, 15.0, and 16.2 mum). The database does not provide any evidence for a correlation of the 13 mum feature with a dust feature at 32 mum, and it is more likely that a weak emission feature at 16.8 mum arises from carbon dioxide gas rather than dust. The correlated dust features at 13, 20, and 28 mum tend to be stronger with respect to the total dust emission in semiregular and irregular variables associated with the asymptotic giant branch than in Mira variables or supergiants. This family of dust features also tends to be stronger in systems with lower infrared excesses and thus lower mass-loss rates. We hypothesize that the dust features arise from crystalline forms of alumina (13 mum) and silicates (20 and 28 mum). C1 Cornell Univ, Infrared Spectrog Sci Ctr, Ithaca, NY 14853 USA. USAF, Res Lab, Space Vehicles Directorate, Bedford, MA 01731 USA. Boston Univ, Inst Astrophys Res, Boston, MA 02215 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Sloan, GC (reprint author), Cornell Univ, Infrared Spectrog Sci Ctr, Ithaca, NY 14853 USA. OI Kraemer, Kathleen/0000-0002-2626-7155 NR 50 TC 57 Z9 57 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2003 VL 594 IS 1 BP 483 EP 495 DI 10.1086/376857 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 717KJ UT WOS:000185087400039 ER PT J AU Slocum, PL Stone, EC Leske, RA Christian, ER Cohen, CMS Cummings, AC Desai, MI Dwyer, JR Mason, GM Mazur, JE Mewaldt, RA von Rosenvinge, TT Wiedenbeck, ME AF Slocum, PL Stone, EC Leske, RA Christian, ER Cohen, CMS Cummings, AC Desai, MI Dwyer, JR Mason, GM Mazur, JE Mewaldt, RA von Rosenvinge, TT Wiedenbeck, ME TI Elemental fractionation in small solar energetic particle events SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : flares; Sun : particle emission ID ADVANCED COMPOSITION EXPLORER; ISOTOPE SPECTROMETER; HE-3-RICH EVENTS; FLARES; ACCELERATION; HE-3; ABUNDANCES; WIND; IONS; SPACECRAFT AB Using the Solar Isotope Spectrometer on the Advanced Composition Explorer ( ACE), we have measured the 11.0 - 21.8 MeV nucleon(-1) heavy (Z greater than or equal to 6) element abundances of 39 small solar energetic particle (SEP) events that occurred between 1998 April 3 and 2002 February 26. Using He isotope data from the Ultra Low-Energy Isotope Spectrometer on ACE, we have classified the events according to their 0.5 - 2.0 MeV nucleon(-1 3)He/He-4 ratios. We find that their average heavy-element composition is similar to that of either large gradual events or He-3-rich events, depending on their He-3/He-4 ratio. As seen in recent studies of small SEP events, we find that the heavy-element intensities relative to C increase with the He-3/He-4 ratios. The dependence of the heavy-element abundances on first ionization potential (FIP) has been derived, using a model consisting of a power law in Q/M (and Z) times a step function in FIP. We report the magnitude of the FIP factor in each event and find that it varies from similar to2 to 7 with no clear dependence on the He-3/He-4 ratio. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Aerosp Corp, Los Angeles, CA 90009 USA. CALTECH, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Florida Inst Technol, Dept Phys & Space Sci, Melbourne, FL 32901 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Christian, Eric/D-4974-2012 OI Christian, Eric/0000-0003-2134-3937 NR 49 TC 15 Z9 15 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2003 VL 594 IS 1 BP 592 EP 604 DI 10.1086/376755 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 717KJ UT WOS:000185087400049 ER PT J AU Dulick, M Bauschlicher, CW Burrows, A Sharp, CM Ram, RS Bernath, P AF Dulick, M Bauschlicher, CW Burrows, A Sharp, CM Ram, RS Bernath, P TI Line intensities and molecular opacities of the FeHF (4)Delta(i)-X (4)Delta(i) transition SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : stars; line : identification; molecular data; stars : atmospheres; stars : fundamental parameters; stars : low-mass, brown dwarfs ID NEAR-INFRARED SPECTRA; WING-FORD BAND; ALL-SKY SURVEY; BASIS-SETS; SOLAR IDENTIFICATION; METAL-HYDRIDES; IRON HYDRIDE; GROUND-STATE; L-DWARFS; ATOMS AB We calculate new line lists and opacities for the F (4)Delta(i) - X (4)Delta(i) transition of FeH. The 0 - 0 band of this transition is responsible for the Wing-Ford band seen in M-type stars, sunspots, and brown dwarfs. The new Einstein A-values for each line are based on a high-level ab initio calculation of the electronic transition dipole moment. The necessary rotational line strength factors (Honl-London factors) are derived for both the Hund's case ( a) and (b) coupling limits. A new set of spectroscopic constants was derived from the existing FeH term values for v = 0, 1, and 2 levels of the X and F states. Using these constants, extrapolated term values were generated for v = 3 and 4 and for J-values up to 50.5. The line lists ( including Einstein A-values) for the 25 vibrational bands with v less than or equal to 4 were generated using a merged list of experimental and extrapolated term values. The FeH line lists were used to compute the molecular opacities for a range of temperatures and pressures encountered in L and M dwarf atmospheres. Good agreement was found between the computed and observed spectral energy distribution of the L5 dwarf 2MASS-1507. C1 Natl Solar Observ, Tucson, AZ 85726 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Arizona, Dept Astron, Tucson, AZ 85721 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. RP Dulick, M (reprint author), Natl Solar Observ, 950 N Cherry Ave,POB 26732, Tucson, AZ 85726 USA. RI Bernath, Peter/B-6567-2012 OI Bernath, Peter/0000-0002-1255-396X NR 51 TC 90 Z9 90 U1 0 U2 4 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2003 VL 594 IS 1 BP 651 EP 663 DI 10.1086/376791 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 717KJ UT WOS:000185087400055 ER PT J AU Georganopoulos, M Kazanas, D AF Georganopoulos, M Kazanas, D TI Decelerating flows in TeV blazars: A resolution to the BL Lacertae-FR I unification problem SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; quasars : general; radiation mechanisms : nonthermal; X-rays : galaxies ID HIGH-ENERGY PHOTONS; PARSEC-SCALE JET; RADIO GALAXIES; GAMMA-RAYS; LUMINOSITY FUNCTIONS; MARKARIAN-501; ABSORPTION; OBJECTS; MODEL; RADIATION AB TeV emission from BL Lacertae (BL) objects is commonly modeled as synchrotron self-Compton radiation from relativistically moving homogeneous plasma blobs. In the context of these models, the blob Lorentz factors needed to reproduce the TeV emission corrected for absorption by the diffuse infrared background are large (delta greater than or similar to 50). The main reason for this is that stronger beaming eases the problem of the lack of similar toIR-UV synchrotron seed photons needed to produce the deabsorbed similar tofew TeV peak of the spectral energy distribution. However, such high Doppler factors are in strong disagreement with the unified scheme, according to which BLs are FR I radio galaxies with their jets closely aligned to the line of sight. Here, motivated by the detection of subluminal velocities in the subparsec-scale jets of the best studied TeV blazars, Mrk 421 and Mrk 501, we examine the possibility that the relativistic flows in the TeV BLs decelerate. In this case, the problem of the missing seed photons is solved because of upstream Compton scattering, a process in which the upstream energetic electrons from the fast base of the flow "see" the synchrotron seed photons produced in the slow part of the flow relativistically beamed. Modest Lorentz factors (Gamma similar to 15), decelerating down to values compatible with the recent radio interferometric observations, reproduce the similar tofew TeV peak energy of these sources. Furthermore, such decelerating flows are shown to be in agreement with the BL-FR I unification, naturally reproducing the observed BL/FR I broadband luminosity ratios. C1 NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Georganopoulos, M (reprint author), NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 25 TC 129 Z9 129 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2003 VL 594 IS 1 BP L27 EP L30 DI 10.1086/378557 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 717KM UT WOS:000185087700007 ER PT J AU Bennett, CL Halpern, M Hinshaw, G Jarosik, N Kogut, A Limon, M Meyer, SS Page, L Spergel, DN Tucker, GS Wollack, E Wright, EL Barnes, C Greason, MR Hill, RS Komatsu, E Nolta, MR Odegard, N Peiris, HV Verde, L Weiland, JL AF Bennett, CL Halpern, M Hinshaw, G Jarosik, N Kogut, A Limon, M Meyer, SS Page, L Spergel, DN Tucker, GS Wollack, E Wright, EL Barnes, C Greason, MR Hill, RS Komatsu, E Nolta, MR Odegard, N Peiris, HV Verde, L Weiland, JL TI First-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: Preliminary maps and basic results SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE cosmicmicrowave background; cosmology : observations; dark matter; early universe; instrumentation : detectors; space vehicles : instruments ID ANGULAR POWER SPECTRUM; BACKGROUND-RADIATION ANISOTROPY; SYSTEMATIC-ERROR ANALYSIS; GALAXY REDSHIFT SURVEY; SMALL-SCALE ANISOTROPY; SKY MAPS; COBE DMR; DARK-MATTER; UNIVERSE; EMISSION AB We present full-sky microwave maps in five frequency bands (23-94 GHz) from the Wilkinson Microwave Anisotropy Probe (WMAP) first-year sky survey. Calibration errors are less than 0.5%, and the low systematic error level is well specified. The cosmic microwave background (CMB) is separated from the foregrounds using multifrequency data. The sky maps are consistent with the 7degrees FWHM Cosmic Background Explorer (COBE) maps. We report more precise, but consistent, dipole and quadrupole values. The CMB anisotropy obeys Gaussian statistics with -5820 agree well with the signal predicted solely from the temperature power spectra, with no additional free parameters. We detect excess power on large angular scales (theta>10degrees) compared to predictions based on the temperature power spectra alone. The excess power is well described by reionization at redshift 11=-1). The combination of WMAP and 2dFGRS data constrains the energy density in stable neutrinos: Omega(nu)h(2)<0.0072 (95% confidence limit). For three degenerate neutrino species, this limit implies that their mass is less than 0.23 eV (95% confidence limit). The WMAP detection of early reionization rules out warm dark matter. C1 Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Dept Phys, Princeton, NJ 08544 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Dept EFI, Chicago, IL 60637 USA. Univ Chicago, Dept CfCP, Chicago, IL 60637 USA. Brown Univ, Dept Phys, Providence, RI 02912 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. Univ Calif Los Angeles, Dept Astron, Los Angeles, CA 90095 USA. RP Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. RI Kogut, Alan/D-6293-2012; Komatsu, Eiichiro/A-4361-2011; Spergel, David/A-4410-2011; Wollack, Edward/D-4467-2012; OI Wollack, Edward/0000-0002-7567-4451; Verde, Licia/0000-0003-2601-8770; Limon, Michele/0000-0002-5900-2698 NR 134 TC 7305 Z9 7346 U1 52 U2 336 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 EI 1538-4365 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2003 VL 148 IS 1 BP 175 EP 194 DI 10.1086/377226 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 715BR UT WOS:000184951100010 ER PT J AU Verde, L Peiris, HV Spergel, DN Nolta, MR Bennett, CL Halpern, M Hinshaw, G Jarosik, N Kogut, A Limon, M Meyer, SS Page, L Tucker, GS Wollack, E Wright, EL AF Verde, L Peiris, HV Spergel, DN Nolta, MR Bennett, CL Halpern, M Hinshaw, G Jarosik, N Kogut, A Limon, M Meyer, SS Page, L Tucker, GS Wollack, E Wright, EL TI First-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: Parameter estimation methodology SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE cosmic microwave background; cosmological parameters; cosmology : observations; methods : data analysis; methods : statistical ID GALAXY REDSHIFT SURVEY; LY-ALPHA FOREST; ANGULAR-CORRELATION FUNCTION; SPACE POWER SPECTRUM; COSMOLOGICAL CONSTANT; BACKGROUND ANISOTROPIES; ACCELERATING UNIVERSE; REAL-SPACE; DENSITY; MORPHOLOGY AB We describe our methodology for comparing the Wilkinson-Microwave Anisotropy Probe (WMAP) measurements of the cosmic microwave background (CMB) and other complementary data sets to theoretical models. The unprecedented quality of the WMAP data and the tight constraints on cosmological parameters that are derived require a rigorous analysis so that the approximations made in the modeling do not lead to significant biases. We describe our use of the likelihood function to characterize the statistical properties of the microwave background sky. We outline the use of the Monte Carlo Markov Chains to explore the likelihood of the data given a model to determine the best-fit cosmological parameters and their uncertainties. We add to the WMAP data the lgreater than or similar to700 Cosmic Background Imager (CBI) and Arcminute Cosmology Bolometer Array Receiver (ACBAR) measurements of the CMB, the galaxy power spectrum at zsimilar to0 obtained from the Two-Degree Field Galaxy Redshift Survey (2dFGRS), and the matter power spectrum at zsimilar to3 as measured with the Lyalpha forest. These last two data sets complement the CMB measurements by probing the matter power spectrum of the nearby universe. Combining CMB and 2dFGRS requires that we include in our analysis a model for galaxy bias, redshift distortions, and the nonlinear growth of structure. We show how the statistical and systematic uncertainties in the model and the data are propagated through the full analysis. C1 Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Dept EFI, Chicago, IL 60637 USA. Univ Chicago, Dept CfCP, Chicago, IL 60637 USA. Brown Univ, Dept Phys, Providence, RI 02912 USA. Univ Calif Los Angeles, Dept Astron, Los Angeles, CA 90095 USA. RP Princeton Univ, Dept Astrophys Sci, Peyton Hall, Princeton, NJ 08544 USA. EM lverde@astro.princeton.edu RI Kogut, Alan/D-6293-2012; Spergel, David/A-4410-2011; Wollack, Edward/D-4467-2012; OI Wollack, Edward/0000-0002-7567-4451; Verde, Licia/0000-0003-2601-8770; Limon, Michele/0000-0002-5900-2698 NR 88 TC 425 Z9 425 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 EI 1538-4365 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2003 VL 148 IS 1 BP 195 EP 211 DI 10.1086/377335 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 715BR UT WOS:000184951100011 ER PT J AU Peiris, HV Komatsu, E Verde, L Spergel, DN Bennett, CL Halpern, M Hinshaw, G Jarosik, N Kogut, A Limon, M Meyer, SS Page, L Tucker, GS Wollack, E Wright, EL AF Peiris, HV Komatsu, E Verde, L Spergel, DN Bennett, CL Halpern, M Hinshaw, G Jarosik, N Kogut, A Limon, M Meyer, SS Page, L Tucker, GS Wollack, E Wright, EL TI First-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: Implications for inflation SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE cosmic microwave background; cosmology : observations; early universe ID COSMIC STRUCTURE FORMATION; ANGULAR POWER SPECTRUM; COSMOLOGICAL PERTURBATIONS; BACKGROUND ANISOTROPIES; DENSITY PERTURBATIONS; GRAVITATIONAL-WAVES; UNIVERSE SCENARIO; ANALYTIC APPROACH; PHASE-TRANSITION; MACHS PRINCIPLE AB We confront predictions of inflationary scenarios with the Wilkinson Microwave Anisotropy Probe (WMAP) data, in combination with complementary small-scale cosmic microwave background (CMB) measurements and large-scale structure data. The WMAP detection of a large-angle anticorrelation in the temperature-polarization cross-power spectrum is the signature of adiabatic superhorizon fluctuations at the time of decoupling. The WMAP data are described by pure adiabatic fluctuations: we place an upper limit on a correlated cold dark matter (CDM) isocurvature component. Using WMAP constraints on the shape of the scalar power spectrum and the amplitude of gravity waves, we explore the parameter space of inflationary models that is consistent with the data. We place limits on inflationary models; for example, a minimally coupled lambdaphi(4) is disfavored at more than 3 sigma using WMAP data in combination with smaller scale CMB and large-scale structure survey data. The limits on the primordial parameters using WMAP data alone are n(s)(k(0)=0.002 Mpc(-1))=1.20(-0.11)(+0.12), dn(s)/d ln k=-0.077(-0.052)(+0.050), A(k(0)=0.002 Mpc(-1))=0.71(-0.11)(+0.10) (68% CL), and r(k(0)=0.002 Mpc(-1))<1.28 (95% CL). C1 Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Dept EFI, Chicago, IL 60637 USA. Univ Chicago, Dept CfCP, Chicago, IL 60637 USA. Brown Univ, Dept Phys, Providence, RI 02912 USA. Univ Calif Los Angeles, Dept Astron, Los Angeles, CA 90095 USA. RP Peiris, HV (reprint author), Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. EM hiranya@astro.princeton.edu RI Kogut, Alan/D-6293-2012; Komatsu, Eiichiro/A-4361-2011; Spergel, David/A-4410-2011; Wollack, Edward/D-4467-2012; OI Wollack, Edward/0000-0002-7567-4451; Verde, Licia/0000-0003-2601-8770; Limon, Michele/0000-0002-5900-2698 NR 86 TC 871 Z9 873 U1 1 U2 11 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2003 VL 148 IS 1 BP 213 EP 231 DI 10.1086/377228 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 715BR UT WOS:000184951100012 ER PT J AU Page, L Nolta, MR Barnes, C Bennett, CL Halpern, M Hinshaw, G Jarosik, N Kogut, A Limon, M Meyer, SS Peiris, HV Spergel, DN Tucker, GS Wollack, E Wright, EL AF Page, L Nolta, MR Barnes, C Bennett, CL Halpern, M Hinshaw, G Jarosik, N Kogut, A Limon, M Meyer, SS Peiris, HV Spergel, DN Tucker, GS Wollack, E Wright, EL TI First-year Wilkinson Microwave Anisotropy Probe (WMAP) observations: Interpretation of the TT and TE angular power spectrum peaks SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE cosmic microwave background; cosmological parameters; cosmology : observations; large-scale structure of universe ID BACKGROUND ANISOTROPIES; COSMOLOGICAL PARAMETERS; ANALYTIC APPROACH; UNIVERSE; CONSTRAINTS; CONSTANT; PERTURBATIONS; RADIATION; LOCATION; DESIGN AB The CMB has distinct peaks in both its temperature angular power spectrum (TT) and temperature-polarization cross-power spectrum (TE). From the WMAP data we find the first peak in the temperature spectrum at l=220.1+/-0.8 with an amplitude of 74.7+/-0.5 muK; the first trough at l=411.7+/-3.5 with an amplitude of 41.0+/-0.5 muK; and the second peak at l+546+/-10 with an amplitude of 48.8+/-0.9 muK. The TE spectrum has an antipeak at l=137+/-9 with a cross-power of -35+/-9 muK(2), and a peak at l=329+/-19 with cross-power 105+/-18 muK(2). All uncertainties are 1 sigma and include calibration and beam errors. An intuition for how the data determine the cosmological parameters may be gained by limiting one's attention to a subset of parameters and their effects on the peak characteristics. We interpret the peaks in the context of a. at adiabatic LambdaCDM model with the goal of showing how the cosmic baryon density, Omega(b)h(2), matter density, Omega(m)h(2), scalar index, n(s), and age of the universe are encoded in their positions and amplitudes. To this end, we introduce a new scaling relation for the TE antipeak-to-peak amplitude ratio and recompute known related scaling relations for the TT spectrum in light of the WMAP data. From the scaling relations, we show that WMAP's tight bound on Omega(b)h(2) is intimately linked to its robust detection of the first and second peaks of the TT spectrum. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Dept EFI, Chicago, IL 60637 USA. Univ Chicago, Dept CfCP, Chicago, IL 60637 USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Brown Univ, Dept Phys, Providence, RI 02912 USA. Univ Calif Los Angeles, Dept Astron, Los Angeles, CA 90095 USA. RP Page, L (reprint author), Princeton Univ, Dept Phys, Jadwin Hall, Princeton, NJ 08544 USA. RI Kogut, Alan/D-6293-2012; Spergel, David/A-4410-2011; Wollack, Edward/D-4467-2012; OI Wollack, Edward/0000-0002-7567-4451; Limon, Michele/0000-0002-5900-2698 NR 61 TC 232 Z9 235 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD SEP PY 2003 VL 148 IS 1 BP 233 EP 241 DI 10.1086/377224 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 715BR UT WOS:000184951100013 ER PT J AU Bhatia, AK Doschek, GA AF Bhatia, AK Doschek, GA TI Atomic data and spectral line intensities for Fe XVII SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Article ID TRANSMISSION GRATING SPECTROMETER; ELECTRON-IMPACT EXCITATION; X-RAY-LINES; EXTREME-ULTRAVIOLET; RESONANCE LINES; CROSS-SECTIONS; RATIOS; PLASMAS; IONS AB Electron impact collision strengths and spontaneous radiative decay rates are calculated for Fe XVII. The data pertain to the 73 levels of the configurations, 2s(2)2p(6), 2s(2)2p(5)3s, 2s(2)2p(5)3p 2s(2)2p(5)3d, 2s2p(6)3s, 2s2p(6)3p, 2s2p(6)3d, 2s(2)2p(5)4s, 2s(2)2p(5)4p, 2s(2)2p(5)4d, 2s2p(6)4s, 2s2p(6)4p, and 2s2p(6)4d. Collision strengths are calculated at 11 incident electron energies: 58.5, 65.0, 70.0, 76.0, 85.0 127.51 170.0, 212.5, 255.0, 340.0, and 425.0 Ry. This work is an improvement over our earlier work on Fe XVII in two respects: (1) configurations involving 4s, 4p, and 4d electrons have been added and (2) a broader range of incident electron energies is used in the computation of collision strengths and excitation rate coefficients. Relative spectral line intensities are calculated for astrophysically important transitions. These are obtained by computing the excitation rate coefficients (cm(3) s(-1)), i.e., the collision strengths integrated over a Maxwellian electron distribution, and then solving the equations of detailed balance for the populations of the 73 energy levels, assuming a collisional excitation model and an electron temperature of 4 x 10(6) K. This temperature is typical for Fe XVII when formed in equilibrium by collisional ionization and recombination. Using the excitation rate coefficients and the radiative decay rates, level populations are computed for five electron densities and are given in this paper. (C) 2003 Elsevier Inc. All rights reserved. C1 USN, Res Lab, EO Hulburst Ctr Space Res, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Lab Astron & Solar Phys, Greenbelt, MD 20771 USA. RP Doschek, GA (reprint author), USN, Res Lab, EO Hulburst Ctr Space Res, Washington, DC 20375 USA. NR 30 TC 7 Z9 7 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 0092-640X J9 ATOM DATA NUCL DATA JI Atom. Data Nucl. Data Tables PD SEP PY 2003 VL 85 IS 1 BP 1 EP 45 DI 10.1016/S0092-640X(02)00018-9 PG 45 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA 722BT UT WOS:000185355800001 ER PT J AU Bhatia, AK Landi, E AF Bhatia, AK Landi, E TI Atomic data and spectral line intensities for S IX SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Article ID EXTREME-ULTRAVIOLET SPECTRA; EMISSION-LINES; RATE COEFFICIENTS; RESONANCE LINES; IONIZED SULFUR; CROSS-SECTIONS; WAVELENGTHS; CHIANTI; IONS; ANGSTROMS AB Electron impact collision strengths, energy levels, oscillator strengths, and spontaneous radiative decay rates are calculated for the O-like ion S IX. The configurations used are 2s(2)2p(4) 2s2p5, 2p(6), 2s(2)2p(3)3s, 2s(2)2p(3)3p, and 2s(2)2p(3)3d giving rise to 86 fine-structure levels in intermediate coupling. Collision strengths are calculated at five incident energies, 25, 50, 75, 100, and 125 Ry. Excitation rate coefficients are calculated by assuming a Maxwellian electron velocity distribution at several electron temperatures in the 5.6 less than or equal to log T-e (K) less than or equal to 6.2 range, where S IX is formed. Using the excitation rate coefficients and the radiative transition rates, statistical equilibrium equations for level populations are solved at electron densities covering the range of 10(8)-10(14) cm(-3). Relative spectral line intensities are calculated. Proton excitation rates among the lowest three levels have been included in the statistical equilibrium equations. The predicted S IX line intensities are compared with SUMER (SOHO) observations of the quiet Sun. (C) 2003 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. USN, Res Lab, ARTEP Inc, Washington, DC 20375 USA. RP Bhatia, AK (reprint author), NASA, Goddard Space Flight Ctr, Code 681, Greenbelt, MD 20771 USA. RI Landi, Enrico/H-4493-2011 NR 30 TC 6 Z9 6 U1 1 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0092-640X J9 ATOM DATA NUCL DATA JI Atom. Data Nucl. Data Tables PD SEP PY 2003 VL 85 IS 1 BP 169 EP 253 DI 10.1016/S0092-640X(03)00057-3 PG 85 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA 722BT UT WOS:000185355800005 ER PT J AU Kaciuba-Uscilko, H Smorawinski, J Nazar, K Adrian, J Greenleaf, FE AF Kaciuba-Uscilko, H Smorawinski, J Nazar, K Adrian, J Greenleaf, FE TI Catecholamine responses to environmental stressors in trained and untrained men after 3-day bed rest SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE norepinephrine; epinephrine; endurance athletes; power/strength athletes; glucose load; orthostatic stand test; cold pressor test; maximal exercise ID SYMPATHETIC-NERVE ACTIVITY; NITRIC-OXIDE RELEASE; SIMULATED MICROGRAVITY; PLASMA NOREPINEPHRINE; ORTHOSTATIC INTOLERANCE; COLD PRESSOR; HUMANS; EXERCISE; DOPAMINE; NORADRENALINE AB Introduction: The effect of decreased physical activity with reduced gravitational stress on activity, sensitivity, and reactivity of the sympathetic nervous system (SNS) is not fully recognized. We hypothesized that the effect is most pronounced in physically active subjects. Thus, basal plasma norepinephrine [NE] and epinephrine [E], and catechol amine responses to physiological stimuli were determined after 3 d of horizontal bed rest (BR) in subjects differing in level and kind of habitual activity. Methods: Before and after BR, 11 untrained students, 8 endurance athletes, and 10 power/strength athletes were submitted to oral glucose tolerance test (OGTT) and orthostatic stand test (OST). Another 32 men (12 untrained, 10 endurance athletes, and 10 power/strength athletes) underwent cold pressor test (CPT) and graded exercise test (GET) performed until volitional exhaustion. Results: After BR, basal [NE] was decreased only in athletes (p < 0.01). Increases in both catecholamines during OGTT were diminished (p < 0.05), particularly in endurance athletes. Plasma [NE] response to standing was not affected by BR in individual groups, but it was diminished in the whole group (p < 0.05). Bed rest did not affect the increases in catecholamines induced by CPT and GET. Heart rate response to OST, and BP responses to OST, CPT, and glucose ingestion were enhanced. Conclusions: Basal sympathetic activity is diminished after 3 d of BR in physically active men. Although catecholamine responses to glucose load and standing were reduced, the general reactivity and sensitivity of SNS were not attenuated since catecholamine responses to the most (exercise) and least (CPT) powerful stimuli were unchanged. C1 Polish Acad Sci, Dept Appl Physiol, Med Res Ctr, PL-02106 Warsaw, Poland. Acad Phys Educ, Dept Sport Med, Poznan, Poland. NASA, Ames Res Ctr, Lab Human Environm Physiol, Moffett Field, CA 94035 USA. RP Kaciuba-Uscilko, H (reprint author), Polish Acad Sci, Dept Appl Physiol, Med Res Ctr, 5 Pawinskiego Str, PL-02106 Warsaw, Poland. NR 36 TC 4 Z9 4 U1 2 U2 2 PU AEROSPACE MEDICAL ASSOC PI ALEXANDRIA PA 320 S HENRY ST, ALEXANDRIA, VA 22314-3579 USA SN 0095-6562 J9 AVIAT SPACE ENVIR MD JI Aviat. Space Environ. Med. PD SEP PY 2003 VL 74 IS 9 BP 928 EP 936 PG 9 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 719DT UT WOS:000185188900002 PM 14503670 ER PT J AU Tonui, E Eggleton, T Taylor, G AF Tonui, E Eggleton, T Taylor, G TI Micromorphology and chemical weathering of a K-rich trachyandesite and an associated sedimentary cover (Parkes, SE Australia) SO CATENA LA English DT Article DE micromorphology; chemical weathering; residual/transported regolith; profile microsystems ID FELDSPAR; MECHANISM; SOILS; SAPROLITE; ANDESITE AB The micromorphology, composition and sequential formation of weathering products of a K-rich trachyandesite and an associated sedimentary cover at Parkes, SE Australia are described. This has been achieved using a combination of mineralogical (optical, X-ray microdiffraction and SEM-EDXA microanalysis) and chemical (X-ray Fluorescence) techniques. The weathering profiles have developed in a low-altitude, relatively flat landscape setting. The following processes are dominant: (a) weathering of primary minerals notably feldspars and micas to transient 'poorly crystalline' oxyhydroxide patches, smectite and ultimately kaolinite; (b) weathering of sediments in a zone of intense solution activity and redox reactions resulting in development of mottles and ferruginous nodules; and (c) greater thickness (up to 350 cm) and compositional differences between the soil over weathered sediments and in situ weathered bedrock. The dominant profile microsystems evolved under a past humid climate later modified by the prevailing semi-arid to and conditions. (C) 2003 Elsevier Science B.V. All rights reserved. C1 Univ Canberra Geosci Australia, CRC LEME, Canberra, ACT 2601, Australia. Australian Natl Univ, Dept Geol, CRC LEME, Canberra, ACT 0200, Australia. Univ Canberra, CRC LEME, Canberra, ACT 2601, Australia. RP Tonui, E (reprint author), CALTECH, Jet Prop Lab, Div Geol & Planetary Sci, Mail Code 170-25, Pasadena, CA 91125 USA. NR 48 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0341-8162 J9 CATENA JI Catena PD SEP 1 PY 2003 VL 53 IS 2 BP 181 EP 207 DI 10.1016/S0341-8162(03)00200-X PG 27 WC Geosciences, Multidisciplinary; Soil Science; Water Resources SC Geology; Agriculture; Water Resources GA 703YP UT WOS:000184311000005 ER PT J AU Zolensky, M Ivanov, A AF Zolensky, M Ivanov, A TI The Kaidun microbreccia meteorite: A harvest from the inner and outer asteroid belt SO CHEMIE DER ERDE-GEOCHEMISTRY LA English DT Review DE Kaidun; asteroids; carbonaceous chondrites; enstatite chondrites; R chondrites; oxygen isotopes ID ENSTATITE CHONDRITE BRECCIA; NEW-SOUTH-WALES; CARBONACEOUS CHONDRITES; AQUEOUS ALTERATION; COMPUTER-SIMULATIONS; MINERAL ASSEMBLAGES; INTERPLANETARY DUST; TAGISH LAKE; FE-NI; INCLUSIONS AB We summarize the results of two decades of research into the complex Kaidun microbrecccia meteorite. This meteorite contains an unprecedented accumulation of materials from many different asteroids, principally carbonaceous and enstatite chondrites, but also many other frequently strange materials. The following well-known meteorite types are definitely present in Kaidun: EH3-5, EL3, CV3, CM1-2, and R chondrites. Also present in Kaidun are new C1 and C2 type lithologies, unique alkaline-enriched clasts, impact melt products, phosphide-bearing clasts, vein- and cavity-filling materials, new enstatite-bearing clasts, and Ca-rich achondrite materials. Many further materials have yet to be characterized. Obviously, the Kaidun parent object accumulated material's from across the entire main asteroid belt. Many of these materials were subjected to varying levels of physical processing, heating, shock, melting, and aqueous alteration. Kaidun is important because it contains many asteroidal materials we have not seen before, providing a more complete view of the diversity of materials in the asteroid belt than has been provided by other meteorites. This is possible because of the small, generally sub-millimeter-size of the component clasts in Kaidun - it is far easier for these smaller objects to scatter throughout the solar system than it is for larger, conventionally-sized meteorites. We suggest that the final parent object where Kaidun was assembled was a large body with a C-type asteroid signature - possible asteroid 1-Ceres or the martian moon Phobos. C1 NASA, Lyndon B Johnson Space Ctr, Astromat Res & Explorat Sci, Houston, TX 77058 USA. Vernadsky Inst, Moscow, Russia. RP Zolensky, M (reprint author), NASA, Lyndon B Johnson Space Ctr, Astromat Res & Explorat Sci, Houston, TX 77058 USA. NR 127 TC 61 Z9 61 U1 4 U2 8 PU URBAN & FISCHER VERLAG PI JENA PA BRANCH OFFICE JENA, P O BOX 100537, D-07705 JENA, GERMANY SN 0009-2819 J9 CHEM ERDE-GEOCHEM JI Chem Erde-Geochem. PD SEP PY 2003 VL 63 IS 3 BP 185 EP 246 DI 10.1078/0009-2819-00038 PG 62 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 758KE UT WOS:000187632900001 ER PT J AU Sun, YC Xu, CK He, XT AF Sun, YC Xu, CK He, XT TI A new 2MASS/2df selected sample of pairs of galaxies and calibration of merging rate in the local universe SO CHINESE PHYSICS LETTERS LA English DT Article ID REDSHIFT SURVEY; MERGER RATE; FIELD GALAXIES; MINOR MERGERS; CLOSE PAIRS; EVOLUTION; STARBURSTS AB We present a new sample of 37 close major-merger galaxy pairs, selected from the 2-degree field redshift survey of the two-micron all-sky survey (2MASS) galaxies. The selection criteria for our near-infrared pairs are more closely related to galaxy mass (a very important parameter in galaxy evolution models) than those for optical selected samples. Our sample benefits enormously from the high homogeneity and accuracy of the 2MASS database, and false matchings are minimized by the essentially three-dimensional selection procedure. Taking into account the biases, we find that 1.96 (+/-0.4)% of galaxies are in close major-merger pairs. This indicates a local merging rate of 1.0%, in good agreement with the results in recent studies of optical selected pairs in the local universe. The results derived with our sample have high confidence. C1 Beijing Normal Univ, Dept Astron, Beijing 100875, Peoples R China. CALTECH, Jet Prop Lab, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. RP Sun, YC (reprint author), Beijing Normal Univ, Dept Astron, Beijing 100875, Peoples R China. NR 29 TC 0 Z9 2 U1 0 U2 0 PU CHINESE PHYSICAL SOC PI BEIJING PA P O BOX 603, BEIJING 100080, PEOPLES R CHINA SN 0256-307X J9 CHINESE PHYS LETT JI Chin. Phys. Lett. PD SEP PY 2003 VL 20 IS 9 BP 1652 EP 1655 DI 10.1088/0256-307X/20/9/370 PG 4 WC Physics, Multidisciplinary SC Physics GA 726UC UT WOS:000185617700070 ER PT J AU Cruikshank, DP Roush, TL Poulet, F AF Cruikshank, DP Roush, TL Poulet, F TI Quantitative modeling of the spectral reflectance of Kuiper Belt objects and Centaurs SO COMPTES RENDUS PHYSIQUE LA English DT Article DE Kuiper Belt; Centaur objects; light scattering; spectroscopy ID COMMON GEOLOGIC MINERALS; MULTIPLE-SCATTERING; PLANETARY SURFACE; WATER ICE; SPECTROSCOPY; PARTICLES; CONSTANTS; LIGHT AB Reflectance spectroscopy of Solar System bodies provides a rich source of information on their compositions (minerals, ices, metals, and macromolecular carbon-bearing materials). Models calculated with radiative transfer theories for the spectral distribution of diffusely scattered sunlight from planetary surfaces yield information on the compositions, abundances, physical states, layering, and particle microstructure of those surfaces. We discuss and evaluate the scattering theories of Hapke and Shkuratov that are widely used for modeling the reflectance spectra and color data for Kuiper Belt objects, Centaur objects, and other airless bodies in the Solar System. Both theories yield good models of the reflectance spectrum of Centaur 5145 Pholus using five components (ices, carbon, a silicate mineral, and a complex organic material), although the derived abundances differ widely. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Paris 11, IAS, F-91405 Orsay, France. RP Cruikshank, DP (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM dcruikshank@mail.arc.nasa.gov NR 33 TC 10 Z9 10 U1 0 U2 4 PU ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS PA 23 RUE LINOIS, 75724 PARIS, FRANCE SN 1631-0705 J9 CR PHYS JI C. R. Phys. PD SEP PY 2003 VL 4 IS 7 BP 783 EP 789 DI 10.1016/j.crhy.2003.10.007 PG 7 WC Astronomy & Astrophysics; Physics, Multidisciplinary SC Astronomy & Astrophysics; Physics GA 769CB UT WOS:000188607900007 ER PT J AU Strazzulla, G Cooper, JF Christian, ER Johnson, RE AF Strazzulla, G Cooper, JF Christian, ER Johnson, RE TI Ion irradiation of TNOs: from the fluxes measured in space to the laboratory experiments SO COMPTES RENDUS PHYSIQUE LA English DT Article DE Trans-Neptunian objects; TNO colors; weathering; TNO chemistry; Ion irradiation; Ion fluxes; Ion populations; anomalous cosmic rays ID ANOMALOUS COSMIC-RAYS; KUIPER-BELT OBJECTS; CARBONACEOUS MATERIAL; COLOR DIVERSITY; CARBONIC-ACID; WATER ICE; SURFACE; COMETARY; TRITON; PLUTO AB Cosmic ion irradiation is believed to be one of the processes driving the evolution of the surface materials on TNOs. We review the laboratory simulations of radiation effects induced in likely TNO materials. In particular the production of new molecular species, the formation of refractory organics, and the spectral changes induced in icy targets and in natural bitumens are described. In order to establish if the effects seen in the laboratory are in fact responsible for the surface properties of the TNOs, the present knowledge of the ion fluxes is reviewed. For objects at selected solar distances, dosage time is given versus depth into the material. As suggested by recent experiments, the contribution of the electronic energy loss and that due to knockon collisions are given separately. The relevance of ion-irradiation for the physico-chemical properties of TNOs is demonstrated, and the need for future investigations is outlined. C1 Osserv Astrofis Catania, INAF, I-95123 Catania, Italy. NASA, Goddard Space Flight Ctr, Raytheon Tech Serv Co, LLC,SSDOO Project, Greenbelt, MD 20771 USA. NASA Headquarters, Off Space Sci, Washington, DC 20546 USA. Univ Virginia, Charlottesville, VA 22903 USA. RP Strazzulla, G (reprint author), Osserv Astrofis Catania, INAF, Via S Sofia 78, I-95123 Catania, Italy. EM gianni@ct.astro.it RI Cooper, John/D-4709-2012; Christian, Eric/D-4974-2012 OI Christian, Eric/0000-0003-2134-3937 NR 48 TC 32 Z9 32 U1 0 U2 2 PU ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER PI PARIS PA 23 RUE LINOIS, 75724 PARIS, FRANCE SN 1631-0705 J9 CR PHYS JI C. R. Phys. PD SEP PY 2003 VL 4 IS 7 BP 791 EP 801 DI 10.1016/j.crhy.2003.10.009 PG 11 WC Astronomy & Astrophysics; Physics, Multidisciplinary SC Astronomy & Astrophysics; Physics GA 769CB UT WOS:000188607900008 ER PT J AU Nurge, MA Youngquist, R Walters, D AF Nurge, MA Youngquist, R Walters, D TI Capacitance based mass metering for cryogenic fluids SO CRYOGENICS LA English DT Article DE hydrogen; nitrogen; oxygen; dielectric properties; instrumentation AB This paper describes a method for measuring the mass of cryogenic fluids in on-board rocket propellant tanks or ground storage tanks. Linear approximations to the Clausius-Mossotti relationship serve as the foundation for a capacitance based mass sensor, regardless of fluid density stratification or tank shape. Sensor design considerations are presented along with the experimental results for a capacitance based mass gage tested in liquid nitrogen. This test data is shown to be consistent with theory resulting in a demonstrated mass measurement accuracy of +/-0.75% and a deviation from linearity of less than +/-0.30% of full scale mass. Theoretical accuracies are also shown to be +/-0.73% for hydrogen and +/-1.39% for oxygen for a select range of pressures and temperatures. Published by Elsevier Ltd. C1 NASA, Kennedy Space Ctr, FL 32899 USA. Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA. RP Nurge, MA (reprint author), NASA, YA-C3-E, Kennedy Space Ctr, FL 32899 USA. NR 4 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD SEP PY 2003 VL 43 IS 9 BP 501 EP 506 DI 10.1016/S0011-2275(03)00127-9 PG 6 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA 715PE UT WOS:000184980300002 ER PT J AU Tunyi, I Guba, P Roth, LE Timko, M AF Tunyi, I Guba, P Roth, LE Timko, M TI Electric discharges in the protoplanetary nebula as a source of impulse magnetic fields to promote dust aggregation SO EARTH MOON AND PLANETS LA English DT Article DE dust grain aggregates; impulse magnetic fields; origin of planetary systems; planetesimals ID CHONDRULES AB Lightning discharge generated in the protoplanetary nebula is viewed as a temporally isolated surge in the flow of electrically charged particles, similar to that of terrestrial lightning. If the current is intense enough, a powerful circular impulse magnetic field is generated around the instantaneous virtual electric conductor. Such magnetic field is capable of magnetizing dust grains containing ferromagnetic components present in its vicinity to their saturation levels. As a result, dust grains attract one another, forming the aggregates. This magnetically driven attraction suggests an important process possibly operational at an early stage of the planetary accretion. Based on both a classical model for electric conductor, and the theory of Lienard-Wiechert electromagnetic potentials, our calculations show that the magnetic impulse due to a discharge channel of a few cm in diameter transferring a charge of about 10(4) electrons reaches as high as 10 T. At these magnetic fields, the ferromagnetic dust grains, and possibly the already-formed larger aggregates as well, are easily magnetized to the saturation levels, producing compact clusters exhibiting permanent magnetic moments. C1 Slovak Acad Sci, Inst Geophys, Bratislava, Slovakia. Comenius Univ, Fac Math Phys & Informat, Dept Geophys, Bratislava, Slovakia. CALTECH, Jet Prop Lab, Pasadena, CA USA. Slovak Acad Sci, Inst Expt Phys, Kosice 04353, Slovakia. RP Tunyi, I (reprint author), Dubravska Cesta 9, Bratislava 84528, Slovakia. EM geoftuny@savba.sk NR 42 TC 3 Z9 3 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0167-9295 J9 EARTH MOON PLANETS JI Earth Moon Planets PD SEP PY 2003 VL 93 IS 1 BP 65 EP 74 DI 10.1023/B:MOON.0000034502.21911.22 PG 10 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA 837CF UT WOS:000222604100004 ER PT J AU Maranchi, JP Hepp, AF Kumta, PN AF Maranchi, JP Hepp, AF Kumta, PN TI High capacity, reversible silicon thin-film anodes for lithium-ion batteries SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID PITCH-POLYSILANE BLENDS; AMORPHOUS-SILICON; LI; NANOCOMPOSITES; TEMPERATURE; ELECTRODES; SYSTEM; TIN AB The properties of amorphous 250 nm and 1 mum silicon films deposited by radio-frequency (rf) magnetron sputtering on copper foil are investigated using X-ray diffraction, scanning electron microscopy (SEM), and electrochemical methods. Galvanostatic half-cell electrochemical measurements conducted between 0.02 and 1.2 V using a lithium counter electrode have shown that the 250 nm Si thin films exhibit an excellent reversible specific capacity of nearly 3500 mAh/g when tested for 30 cycles. The high reversible capacity and excellent cyclability of the 250 nm sputtered silicon thin films suggest excellent adhesion between Si and Cu leading to high capacity retention. SEM analysis conducted on the 250 nm Si films after the 30th charge suggests the good adhesion of the similar to2 mum diam "plates" of silicon to the copper substrate. (C) 2003 The Electrochemical Society. C1 Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. NASA, Glenn Res Ctr, Photovolta & Space Environm Branch, Cleveland, OH 44135 USA. RP Maranchi, JP (reprint author), Carnegie Mellon Univ, Dept Mat Sci & Engn, Pittsburgh, PA 15213 USA. NR 23 TC 255 Z9 268 U1 24 U2 208 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD SEP PY 2003 VL 6 IS 9 BP A198 EP A201 DI 10.1149/1.1596918 PG 4 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 706RX UT WOS:000184469400009 ER PT J AU Xu, XH Shi, Y Liu, SH Wang, HP Chang, SG Fisher, JW Pisharody, S Moran, M Wignarajah, K AF Xu, XH Shi, Y Liu, SH Wang, HP Chang, SG Fisher, JW Pisharody, S Moran, M Wignarajah, K TI Method for the control of NOx emissions in long-range space travel SO ENERGY & FUELS LA English DT Article ID ACTIVATED CARBON-FIBERS; FLUE-GAS; NITRIC-OXIDE; SULFUR-DIOXIDE; ELEMENTAL SULFUR; COMBINED REMOVAL; SO2; REDUCTION; OXIDATION; ABSORPTION AB The wheat straw, an inedible biomass that can be continuously produced in a space vehicle has been used to produce activated carbon for effective control of NO, emissions from the incineration of wastes. The optimal carbonization temperature of wheat straw was found to be around 600degreesC when a burnoff of 67% was observed. The BET surface area of the activated carbon produced from the wheat straw reached as high as 300 m(2)/g. The presence of oxygen in flue gas is essential for effective adsorption of NO by activated carbon. On the contrary, water vapor inhibits the adsorption efficiency of NO. Consequently, water vapor in flue gas should be removed by drying agents before adsorption to ensure high NO adsorption efficiency. All of the NO in the flue gas was removed for more than 2 h by the activated carbons when 10% oxygen was present and the ratio of carbon weight to the flue gas flow rate (W/F) was 30 g.min/L, with a contact time of 10.2 s. All of NO was reduced to N-2 by the activated carbon at 450degreesC with a W/F ratio of 15 g.min/L and a contact time of 5.1 s. Reduction of the adsorbed NO also regenerated the activated carbon, and the regenerated activated carbon exhibited an improved NO adsorption efficiency. However, the reduction of the adsorbed NO resulted in a loss of carbon which was determined to be about 0.99% of the activated carbon per cycle of regeneration. The sufficiency of the amount of wheat straw in providing the activated carbon based on a six-person crew, such as the mission planned for Mars, has been determined. This novel approach for the control of NO, emissions is sustainable in a closed system such as the case in space travel. It is simple to operate and is functional under microgravity environment. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Astrobiol Technol Branch, Moffett Field, CA 94035 USA. RP Chang, SG (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. RI Liu, Shou-Heng/B-3391-2008 OI Liu, Shou-Heng/0000-0002-4852-874X NR 50 TC 3 Z9 4 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 2003 VL 17 IS 5 BP 1303 EP 1310 DI 10.1021/ef0300803 PG 8 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 723ZU UT WOS:000185462200023 PM 14672086 ER PT J AU Tseng, KK Tinker, ML Lassiter, JO Peairs, DM AF Tseng, KK Tinker, ML Lassiter, JO Peairs, DM TI Temperature dependency of impedance-based nondestructive testing SO EXPERIMENTAL TECHNIQUES LA English DT Article DE smart material; NDT; NDE; impedance; piezoceramics; PZT C1 Vanderbilt Univ, Dept Civil & Environm Engn, Nashville, TN 37235 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Virginia Tech, Dept Mech Engn, Blacksburg, VA USA. RP Tseng, KK (reprint author), Vanderbilt Univ, Dept Civil & Environm Engn, Nashville, TN 37235 USA. NR 10 TC 8 Z9 8 U1 0 U2 2 PU SOC EXPERIMENTAL MECHANICS PI BETHEL PA 7 SCHOOL STREET, BETHEL, CT 06801 USA SN 0732-8818 J9 EXP TECHNIQUES JI Exp. Tech. PD SEP-OCT PY 2003 VL 27 IS 5 BP 33 EP 36 DI 10.1111/j.1747-1567.2003.tb00127.x PG 4 WC Engineering, Mechanical; Mechanics; Materials Science, Characterization & Testing SC Engineering; Mechanics; Materials Science GA 731FX UT WOS:000185874800009 ER PT J AU Armendariz-Picon, C Greene, PB AF Armendariz-Picon, C Greene, PB TI Spinors, inflation, and non-singular cyclic cosmologies SO GENERAL RELATIVITY AND GRAVITATION LA English DT Article DE cosmology; spinor field; inflation ID SELF-CONSISTENT SOLUTIONS; PERFECT FLUID; FIELDS; SUPERCONDUCTIVITY; QUANTIZATION; DRIVEN AB We consider toy cosmological models in which a classical, homogeneous, spinor field provides a dominant or sub-dominant contribution to the energy-momentum tensor of a flat Friedmann-Robertson-Walker universe. We find that, if such a field were to exist, appropriate choices of the spinor self-interaction would generate a rich variety of behaviors, quite different from their widely studied scalar field counterparts. We first discuss solutions that incorporate a stage of cosmic inflation and estimate the primordial spectrum of density perturbations seeded during such a stage. Inflation driven by a spinor field turns out to be unappealing as it leads to a blue spectrum of perturbations and requires considerable fine-tuning of parameters. We next find that, for simple, quartic spinor self-interactions, non-singular cyclic cosmologies exist with reasonable parameter choices. These solutions might eventually be incorporated into a successful past- and future-eternal cosmological model free of singularities. In an Appendix, we discuss the classical treatment of spinors and argue that certain quantum systems might be approximated in terms of such fields. C1 Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. NASA, Fermilab Astrophys Grp, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. EM armen@oddjob.uchicago.edu OI Armendariz Picon, Cristian/0000-0001-9480-3282 NR 44 TC 87 Z9 88 U1 0 U2 1 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0001-7701 EI 1572-9532 J9 GEN RELAT GRAVIT JI Gen. Relativ. Gravit. PD SEP PY 2003 VL 35 IS 9 BP 1637 EP 1658 DI 10.1023/A:1025783118888 PG 22 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 722ZE UT WOS:000185407300009 ER PT J AU Borg, LE Nyquist, LE Wiesmann, H Shih, CY Reese, Y AF Borg, LE Nyquist, LE Wiesmann, H Shih, CY Reese, Y TI The age of Dar al Gani 476 and the differentiation history of the martian meteorites inferred from their radiogenic isotopic systematics SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID MANTLE-CRUST SYSTEM; TI MARE BASALTS; DAR AL GANI-476; RB-SR; SM-ND; SNC METEORITES; TERRESTRIAL PLANETS; RAPID ACCRETION; OXYGEN FUGACITY; PB SYSTEMATICS AB Samarium-neodymium isotopic analysis of the martian meteorite Dar al Gani 476 yields a crystallization age of 474 +/- 11 Ma and an initial epsilon(ND)(143) value of +36.6 +/- 0.8. Although the Rb-Sr isotopic system has been disturbed by terrestrial weathering, and therefore yields no age information, an initial Sr-87/Sr-86 ratio of 0.701249 +/- 33 has been estimated using the Rb-Sr isotopic composition of the maskelynite mineral fraction and the Sm-Nd age. The Sr and Nd isotopic systematics of Dar al Gani 476, like those of the basaltic shergottite QUE94201, are consistent with derivation from a source region that was strongly depleted in incompatible elements early in the history of the solar system. Nevertheless, Dar al Gani 476 is derived from a source region that has a slightly greater incompatible enrichment than the QUE94201 source region. This is not consistent with the fact that the parental magma of Dar al Gani 476 is significantly more mafic than the parental magma of QUE94201, and underscores a decoupling between the major element and trace element-isotopic systematics observed in the martian meteorite suite. Combining the epsilon(ND)(142)-epsilon(ND)(143) isotopic systematics of the martian meteorites yields a model age for planetary differentiation of 4.513(+0.033)(-0.027) Ga. Using this age, the parent/daughter ratios of martian mantle sources are calculated assuming a two-stage evolutionary history. The calculated sources have very large ranges of parent/daughter ratios (Rb-87/Sr-86 = 0.037-0.374; Sm-147/Nd-144 = 0.182-0.285; Lu-176/Hf-177 = 0.028-0.048). These ranges exceed the ranges estimated for terrestrial basalt source regions, but are very similar to those estimated for the sources of lunar mare basalts. In fact, the range of parent/daughter ratios calculated for the martian meteorite sources can be produced by mixing between end-members with compositions similar to lunar mare basalt sources. Two of the sources have compositions that are similar to olivine and pyroxene-rich mafic cumulates with variable proportions of a Rb-enriched phase, such as amphibole, whereas the third source has the composition of liquid trapped in the cumulate pile (i.e. similar to KREEP) after similar to99% crystallization. Correlation between the proportion of trapped liquid in the meteorite source regions and estimates of f(O2), suggest that the KREEP-like component may be hydrous. The success of these models in reproducing the martian meteorite source compositions suggests that the variations in trace element and isotopic compositions observed in the martian meteorites primarily reflect melting of the crystallization products of an ancient magma ocean, and that assimilation of evolved crust by mantle derived magmas is not required. Furthermore, the decoupling of major element and trace element-isotopic systematics in the martian meteorite suite may reflect the fact that trace element and isotopic systematics are inherited from the magma source regions, whereas the major element abundances are limited by eutectic melting processes at the time of magma formation. Differences in major element abundances of parental magma, therefore, result primarily from fractional crystallization after leaving their source regions. Copyright (C) 2003 Elsevier Ltd. C1 Univ New Mexico, Inst Meteorit, Albuquerque, NM 87131 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Lockheed Engn & Sci Co, Houston, TX 77258 USA. RP Univ New Mexico, Inst Meteorit, Albuquerque, NM 87131 USA. EM lborg@unm.edu NR 89 TC 106 Z9 106 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 2003 VL 67 IS 18 BP 3519 EP 3536 DI 10.1016/S0016-7037(00)00094-2 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 723PT UT WOS:000185441300014 ER PT J AU Burbine, TH O'Brien, KM Buchanan, PC AF Burbine, TH O'Brien, KM Buchanan, PC TI Chondritic building blocks of Vesta SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 Natl Inst Polar Res, Itabashi Ku, Tokyo 1738515, Japan. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. EM tburbine@lepvax.gsfc.nasa.gov; kobrien@socal.rr.com; buchanan@nipr.ac.jp NR 1 TC 0 Z9 0 U1 0 U2 1 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A49 EP A49 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600094 ER PT J AU Fries, MD Hall, JA Toporski, J Hedgecock, J Bar-Cohen, Y Wainwright, N Avci, R Lynch, K Steele, A AF Fries, MD Hall, JA Toporski, J Hedgecock, J Bar-Cohen, Y Wainwright, N Avci, R Lynch, K Steele, A TI A novel portable simulated rover platform (SimRP) for astrobiology exploration rover development SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 NASA, Lyndon B Johnson Space Ctr, JSC Astrobiol Inst, Houston, TX 77058 USA. Montana State Univ, ICAL, Bozeman, MT 59717 USA. Marine Biol Lab, Woods Hole, MA 02543 USA. NASA, Jet Prop Lab, Pasadena, CA USA. Oceaneering Space Syst, Houston, TX USA. Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. EM m.fries@gl.ciw.edu NR 0 TC 0 Z9 0 U1 0 U2 0 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A105 EP A105 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600203 ER PT J AU Hudon, P Martignole, J Gauthier, G AF Hudon, P Martignole, J Gauthier, G TI Mantle signature of trace element-poor zircon from the Cabonga Nepheline Syenite Complex (Grenville Province, Western Quebec) SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Montreal, Dept Geol, Montreal, PQ H3C 3J7, Canada. EM pierre.hudon1@jsc.nasa.gov; jacques.g.martignole@umontreal.ca; gilles.gauthier@umontreal.ca NR 1 TC 0 Z9 0 U1 0 U2 1 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A162 EP A162 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600317 ER PT J AU Jones, JH AF Jones, JH TI Young volcanism from depleted source regions: A SNC paradox SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 NASA, Lyndon B Johnson Space Ctr, SR, Houston, TX 77058 USA. EM jones2@ems.jsc.nasa.gov NR 5 TC 0 Z9 0 U1 0 U2 0 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A191 EP A191 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600376 ER PT J AU Koizumi, E Mikouchi, T McKay, G Monkawa, A Le, L Miyamoto, M AF Koizumi, E Mikouchi, T McKay, G Monkawa, A Le, L Miyamoto, M TI Porphyritic texture in linear cooling experiments: Implications for the origins of porphyritic grains in basaltic rocks SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 Univ Tokyo, Dept Earth & Planetary Sci, Tokyo, Japan. Univ Tokyo, Univ Musium, Tokyo, Japan. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Lockheed Maertin, Houston, TX USA. EM koi@space.eps.s.u-tokyo.ac.jp NR 2 TC 1 Z9 1 U1 0 U2 1 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A227 EP A227 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600447 ER PT J AU Kondo, Y Chen, G Hudman, R Jacob, D Koike, M Nakamura, K Takegawa, N Kita, K Miyazaki, Y Blake, DR Shirai, T Kawakami, S Takigawa, M Akimoto, H Ogawa, T AF Kondo, Y Chen, G Hudman, R Jacob, D Koike, M Nakamura, K Takegawa, N Kita, K Miyazaki, Y Blake, DR Shirai, T Kawakami, S Takigawa, M Akimoto, H Ogawa, T TI Photochemistry of ozone over the Western Pacific in Winter and Spring SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 Univ Tokyo, Adv Sci & Technol Res Ctr, Tokyo, Japan. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Harvard Univ, Dept Earth & Planetary Sci, Cambridge, MA 02138 USA. Univ Tokyo, Dept Earth & Planetary Sci, Tokyo, Japan. Ibaraki Univ, Dept Environm Sci, Ibaraki, Japan. Univ Calif Irvine, Dept Environm, Irvine, CA USA. EM kondo@atmos.rcast.u-tokyo.ac.jp RI Hudman, Rynda/C-6118-2009; Koike, Makoto/F-4366-2011; Kondo, Yutaka/D-1459-2012 NR 0 TC 0 Z9 0 U1 0 U2 0 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A232 EP A232 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600456 ER PT J AU McKay, G Le, L Mikouchi, T Koizumi, E AF McKay, G Le, L Mikouchi, T Koizumi, E TI Can the Eu oxygen barometer be applied to QUE 94201? SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN ID UPPER-MANTLE; PETROGENESIS; CONSTRAINTS; STATE; MARS C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Lockheed Martin, Houston, TX 77058 USA. Univ Tokyo, Dept Earth & Planetary Sci, Tokyo 1130033, Japan. EM Gordon.Mckay@jsc.nasa.gov NR 4 TC 0 Z9 0 U1 0 U2 0 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A285 EP A285 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600560 ER PT J AU Messenger, S Keller, LP AF Messenger, S Keller, LP TI Silicate stardust from comets SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN ID INTERPLANETARY DUST; GRAINS C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM scott.r.messenger@nasa.gov; lindsay.p.keller@nasa.gov NR 6 TC 0 Z9 0 U1 0 U2 0 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A288 EP A288 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600566 ER PT J AU Mikouchi, T McKay, G AF Mikouchi, T McKay, G TI Mineralogy and petrogenesis of quenched angrite meteorites SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Tokyo, Grad Sch Sci, Dept Earth & Planetary Sci, Tokyo 1130033, Japan. EM mikouchi@eps.s.u-tokyo.ac.jp; Gordon.McKay@jsc.nasa.gov NR 1 TC 0 Z9 0 U1 0 U2 3 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A291 EP A291 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600572 ER PT J AU Misawa, K Shih, CY Wiesmann, H Nyquist, LE Noguchi, T AF Misawa, K Shih, CY Wiesmann, H Nyquist, LE Noguchi, T TI When did aqueous alteration occur on the Martian surface? SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN ID METEORITE C1 NIPR, Tokyo, Japan. Lockheed Martin Co, Houston, TX USA. NASA, Lyndon B Johnson Space Ctr, SR, Houston, TX 77058 USA. Ibaraki Univ, Ibaraki, Japan. EM misawa@nipr.ac.jp; yu.shih1@jsc.nasa.gov; l.nyquist@jsc.nasa.gov; tngc@mx.ibaraki.ac.jp NR 4 TC 0 Z9 0 U1 0 U2 0 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A294 EP A294 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600578 ER PT J AU Nakamura, K Nakashima, S Tomita, S Zolensky, ME Keller, LP Tomeoka, K AF Nakamura, K Nakashima, S Tomita, S Zolensky, ME Keller, LP Tomeoka, K TI Hollow organic globules in the Tagish Lake meteorite as possible products of primitive organic reactions SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Tokyo Inst Technol, Interact Res Ctr Sci, Tokyo 1528551, Japan. Inst Phys & Chem Res, Nanomat Proc Lab, Wako, Saitama 3510198, Japan. Kobe Univ, Kobe, Hyogo 6578501, Japan. EM keiko.nakamural@jsc.nasa.gov RI Tomita, Satoshi/A-4008-2011 OI Tomita, Satoshi/0000-0002-2514-9675 NR 3 TC 1 Z9 1 U1 1 U2 4 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A325 EP A325 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600640 ER PT J AU Nemchin, AA Meyer, C Pidgeon, RT AF Nemchin, AA Meyer, C Pidgeon, RT TI The early evolution of the Earth and Moon: Comparative chronology SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN ID DETRITAL ZIRCONS; ISOTOPES; CRUST; AGES C1 Curtin Univ Technol, Perth, WA 6001, Australia. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM rnemchin@alpha2.curtin.edu.au; charles_meyer-1@nasa.gov NR 5 TC 1 Z9 1 U1 0 U2 2 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A333 EP A333 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600655 ER PT J AU Nyquist, LE Shih, CY AF Nyquist, LE Shih, CY TI Searching for the crustal component in Martian meteorites SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 NASA, Lyndon B Johnson Space Ctr, SR, Houston, TX 77058 USA. Lockheed Martin Co, Houston, TX USA. EM laurence.e.nyquist1@jsc.nasa.gov; chi-yu.shih1@jsc.nasa.gov NR 6 TC 0 Z9 0 U1 0 U2 0 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A343 EP A343 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600676 ER PT J AU Ono, S Rumble, D Pavlov, A Eigenbrode, J Kasting, J Lindsay, J Freeman, K AF Ono, S Rumble, D Pavlov, A Eigenbrode, J Kasting, J Lindsay, J Freeman, K TI Mass-independent sulfur isotope records from the Hamersley Basin, Austrlaia SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. Univ Colorado, LASP, Boulder, CO 80309 USA. Penn State Univ, Astrobiol Res Ctr, University Pk, PA 16802 USA. Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM s.ono@gl.ciw.edu RI Freeman, Katherine/H-5140-2011; Eigenbrode, Jennifer/D-4651-2012 OI Freeman, Katherine/0000-0002-3350-7671; NR 1 TC 1 Z9 1 U1 0 U2 3 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A362 EP A362 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600714 ER PT J AU Ootsubo, T Onaka, T Yamamura, I Ishihara, D Tanabe, T Roellig, TL AF Ootsubo, T Onaka, T Yamamura, I Ishihara, D Tanabe, T Roellig, TL TI Mid-infrared observation of the zodiacal light - Crystalline silicates in interplanetary space SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 Natl Astron Observ Japan, Mitaka, Tokyo, Japan. Univ Tokyo, Bunkyo Ku, Tokyo 113, Japan. Inst Space & Astronaut Sci, Sagamihara, Kanagawa 229, Japan. Univ Tokyo, Inst Astron, Mitaka, Tokyo 181, Japan. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM ootsbotk@cc.nao.ac.jp; onaka@astron.s.u-tokyo.ac.jp; yamamura@ir.isas.ac.jp; ishihara@astron.s.u-tokyo.ac.jp; ttanabe@ioa.s.u-tokyo.ac.jp; Thomas.L.Roellig@nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A363 EP A363 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600716 ER PT J AU Runnegar, B Coath, CD Lyons, JR McKeegan, KD Mojzsis, SJ AF Runnegar, B Coath, CD Lyons, JR McKeegan, KD Mojzsis, SJ TI Mass-dependent and mass-independent sulfur isotopic effects in Archean and Paleoproterozoic sulfides and sulfates SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 NASA, Ames Res Ctr, Astrobiol Inst, Moffett Field, CA 94035 USA. Univ Bristol, Dept Earth Sci, Bristol BS8 1RJ, Avon, England. Univ Calif Los Angeles, IGPP Ctr Astrobiol, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Univ Colorado, Dept Geosci, Boulder, CO 80303 USA. EM bruce.runnegar@nasa.gov; Chris.Coath@bristol.ac.uk; jrl@ess.ucla.edu; kdm@ess.ucla.edu; mojzsis@colorado.edu RI McKeegan, Kevin/A-4107-2008 OI McKeegan, Kevin/0000-0002-1827-729X NR 1 TC 0 Z9 0 U1 0 U2 1 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A404 EP A404 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600796 ER PT J AU Runnegar, B AF Runnegar, B TI Oxygenating a planet: Astrobiological implications SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 NASA, Ames Res Ctr, Astrobiol Inst, Moffett Field, CA 94035 USA. EM bruce.runnegar@nasa.gov RI McKeegan, Kevin/A-4107-2008 OI McKeegan, Kevin/0000-0002-1827-729X NR 0 TC 0 Z9 0 U1 0 U2 1 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A404 EP A404 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517600795 ER PT J AU Zahnle, K Sleep, N Nimmo, F AF Zahnle, K Sleep, N Nimmo, F TI Heat flow and helium and argon degassing in whole mantle convection SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 NASA, Ames Res Ctr, Ames, IA USA. UCL, London, England. EM Kevin.J.Zahnle@nasa.gov NR 0 TC 0 Z9 0 U1 1 U2 2 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A574 EP A574 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517601130 ER PT J AU Zahnle, K AF Zahnle, K TI Hadean Earth SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Meeting Abstract CT 13th Annual VM Goldschmidt Conference CY SEP 07-12, 2003 CL KURASHIKI, JAPAN C1 NASA, Ames Res Ctr, Ames, IA USA. EM Kevin.J.Zahnle@nasa.gov NR 0 TC 0 Z9 0 U1 1 U2 2 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 SEP PY 2003 VL 67 IS 18 SU 1 BP A574 EP A574 PG 1 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 724ZF UT WOS:000185517601129 ER PT J AU Tesfaye, S Harding, DJ Kusky, TM AF Tesfaye, S Harding, DJ Kusky, TM TI Early continental breakup boundary and migration of the Afar triple junction, Ethiopia SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article DE Africa; rift; structural geology; remote sensing; tectonics; triple junction ID AFRICAN RIFT SYSTEM; SOMALIA PLATE BOUNDARY; RED-SEA; HYDROCARBON EXPLORATION; EXTENSIONAL TECTONICS; GEOLOGICAL EVOLUTION; DANAKIL-BLOCK; MANTLE PLUME; EAST-AFRICA; GULF AB Megascale accommodation zones mark the early continental breakup boundary of the Afro-Arabian plateau in Ethiopia. Motion along these megascale accommodation zones enabled the different arms of the Afar RRR (rift-rift-rift) triple junction to join together. An arcuate accommodation zone similar to45 km wide and similar to60 km long marks the transition from the N25degreesW-striking Southern Red Sea Rift trend in the western Afar margin to the N25degreesE-striking Main Ethiopian Rift. Another accommodation zone similar to80 km long marks the transition between the northeast- to north-northeast-trending Main Ethiopian Rift and the nearly east-trending Gulf of Aden. The positions of accommodation zones where rift orientations change by similar to50degrees suggest that they served as soft linking points between the kinematically "misaligned" arms of the triple junction during the initial breakup of the Afro-Arabian dome. We use structural features to infer the present location of the triple junction in the Lake Abbe area. On the basis of the location of the paleo-triple junction, deduced from the position of accommodation zones and geomorphic considerations, it is estimated that the Afar triple junction has migrated similar to1.5degrees (similar to160 km) in a north-northeast direction with respect to the African (Nubian) plate. The estimated amount of migration of the Afar triple junction is less than the 200 kin migration expected from plate-kinematic. analysis. This discrepancy suggests either a slower rate of spreading than the current similar to1.6 cm/yr (Africa-Arabia) during the early phase of rifting or a later early Miocene rather than Oligocene-Miocene age for the initiation of tectonic activity in the triple junction. C1 St Louis Univ, Dept Earth & Atmospher Sci, St Louis, MO 63103 USA. NASA, Goddard Space Flight Ctr, Geodynam Branch, Greenbelt, MD 20771 USA. RP Kusky, TM (reprint author), St Louis Univ, Dept Earth & Atmospher Sci, St Louis, MO 63103 USA. RI Kusky, Timothy/E-6016-2010; OI Kusky, Timothy/0000-0002-4553-620X NR 96 TC 43 Z9 43 U1 0 U2 11 PU ASSOC ENGINEERING GEOLOGISTS GEOLOGICAL SOCIETY AMER PI DENVER PA 720 S COLORADO BLVD, STE 960-S, DENVER, CO 80246 USA SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD SEP PY 2003 VL 115 IS 9 BP 1053 EP 1067 DI 10.1130/B25149.1 PG 15 WC Geosciences, Multidisciplinary SC Geology GA 717EX UT WOS:000185074100003 ER PT J AU Nealson, K Berelson, W AF Nealson, K Berelson, W TI Layered microbial communities and the search for life in the universe SO GEOMICROBIOLOGY JOURNAL LA English DT Article DE geochemical gradients; layered microbial communities; life detection; organic carbon burial efficiency; sediment diagenesis ID LAKE-MICHIGAN SEDIMENT; DEEP-SEA; DIAGENESIS; PHOTOSYNTHESIS; BORDERLAND; FLUXES; OXYGEN; MATTER; WATER; PH AB Searching for life when we do not know what it is like is at best a difficult task, and at worst, an exercise fraught with frustration and potential failure. In developing methods that will have general applicability, one must ascertain first what the general,features of life might be that, when present, would provide strong inference of the presence of active lift. We propose here that the tendency of life to be associated with energetic gradients, in fact to create its own gradients via the catalytic consumption of nutrients and oxidants, and the production of waste products, is one of the general features of active extant life. As life seeks out and creates such gradients, layered microbial communities, or LMCs, result that are in their own way; prima facie biosignatures. These LMCs are abundant, perhaps ubiquitous in physically stratified environments on our own planet. If energy flows through a given system, and if life has developed efficient catalytic methods to utilize this energy; then LMCs are predicted to be present. Here we discuss the general issues of what can be gleaned from the study of LMCs in terms of energy flow, carbon flow, and carbon storage in earthly ecosystems, as well as the philosophy of using LMCs as biosignatures in the search for life on Earth, and perhaps, lit extraterrestrial sites. C1 Univ So Calif, Dept Earth Sci, Los Angeles, CA 90089 USA. Jet Prop Lab, Ctr Life Detect, Pasadena, CA USA. RP Nealson, K (reprint author), Univ So Calif, Dept Earth Sci, Los Angeles, CA 90089 USA. EM knealson@usc.edu NR 22 TC 12 Z9 14 U1 0 U2 6 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0149-0451 J9 GEOMICROBIOL J JI Geomicrobiol. J. PD SEP-OCT PY 2003 VL 20 IS 5 BP 451 EP 462 DI 10.1080/01490450390236950 PG 12 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA 729HC UT WOS:000185766800004 ER PT J AU Delozier, DM Orwoll, RA Cahoon, JF Ladislaw, JS Smith, JG Connell, JW AF Delozier, DM Orwoll, RA Cahoon, JF Ladislaw, JS Smith, JG Connell, JW TI Polyimide nanocomposites prepared with a novel aromatic surfactant SO HIGH PERFORMANCE POLYMERS LA English DT Article DE polyimide; nanocomposite; organoclay ID SMECTIC CLAY/POLY(METHYL METHACRYLATE); MECHANICAL-PROPERTIES; CLAY NANOCOMPOSITES; THERMAL-STABILITY; HIGH-TEMPERATURE; MONTMORILLONITE; ORIENTATION; ORGANOCLAY; POLYMER AB Montmorillonite clays modified with 1,5-bis(3-aminophenoxy)-3-oxapentane dihydrochloride (BAOD) were used in the preparation of polyimide/organoclay hybrid films. Organoclays with varying surface charge based upon BAOD were prepared and examined for their dispersion behavior in the polymer matrix. Initial evaluation was performed by preparing high molecular weight poly(amide acid) solutions in the presence of the organoclays at a 3 wt% loading. Films were cast and subsequently heated to 300 degreesC to cause imidization. The resulting nanocomposite films were characterized by transmission electron microscopy and x-ray diffraction. It was found that the clay's cation exchange capacity (CEC) played a key role in determining the extent of dispersion in the polyimide matrix. Considerable dispersion was observed in nanocomposite films prepared from organoclays possessing medium and high CECs. One organoclay that dispersed well was further evaluated in nanocomposite films at weight loadings of 5 and 8%. The nanocomposite films were characterized by transmission electron microscopy, x-ray diffraction, and thin-film tensile testing. High levels of clay dispersion were achieved even at the higher clay loadings. Mechanical testing of these films showed that the moduli of the materials increased with increasing clay concentration, but the strength and elongation were generally adversely affected. C1 NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. Coll William & Mary, Dept Appl Sci, Williamsburg, VA 23187 USA. Coll William & Mary, Dept Chem, Williamsburg, VA 23187 USA. RP Connell, JW (reprint author), NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. NR 23 TC 5 Z9 5 U1 1 U2 3 PU SAGE PUBLICATIONS LTD PI LONDON PA 6 BONHILL STREET, LONDON EC2A 4PU, ENGLAND SN 0954-0083 J9 HIGH PERFORM POLYM JI High Perform. Polym. PD SEP PY 2003 VL 15 IS 3 BP 329 EP 346 DI 10.1177/0954008303015003009 PG 18 WC Polymer Science SC Polymer Science GA 722NH UT WOS:000185382100009 ER PT J AU Lunine, JI Chambers, J Morbidelli, A Leshin, LA AF Lunine, JI Chambers, J Morbidelli, A Leshin, LA TI The origin of water on Mars SO ICARUS LA English DT Article DE origin, solar system; Mars, interior; Mars, atmosphere; planetesimals ID HF-W CHRONOMETRY; TERRESTRIAL PLANETS; MARTIAN METEORITE; ASTEROID BELT; SOLAR-SYSTEM; EARTH; RESERVOIRS; ATMOSPHERE; VOLATILES; EVOLUTION AB This paper considers the origin of water on Mars, in the context of a dynamical model that accounts for most of the Earth's water as a product of collisions between the growing Earth and planet-sized "embryos" from the asteroid belt. Mars' history is found to be different; to explain the present mass of Mars requires that it suffer essentially no giant collisions and the bulk of its growth is through addition of smaller bodies. Asteroids and comets from beyond 2.5 AU provide the source of Mars' water, which totals 6-27% of the Earth's present ocean (I Earth ocean equivalent to 1.5 x 10(21) kg), equivalent to 600-2700-m depth on the martian surface. The D/H ratio of this material is 1.2-1.6 times Standard Mean Ocean Water, the smaller value obtaining for the larger amount of water accreted. The upper half of the range of total water accreted, while many times less than that acquired by the Earth, is consistent with geological data on Mars, and the D/H value is that derived for martian magmatic water from SNC meteorites. Both together are consistent with published interpretations of the high D/H in present-day martian atmospheric water in terms of water loss through atmospheric escape. (C) 2003 Elsevier Inc. All rights reserved. C1 Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. SETI Inst, Mountain View, CA 94043 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Observ Cote Azur, F-06304 Nice 4, France. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. RP Lunine, JI (reprint author), Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. NR 40 TC 91 Z9 90 U1 1 U2 15 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD SEP PY 2003 VL 165 IS 1 BP 1 EP 8 DI 10.1016/S0019-1035(03)00172-6 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 721VB UT WOS:000185338200001 ER PT J AU Fairen, AG Dohm, JM Baker, VR de Pablo, MA Ruiz, J Ferris, JC Anderson, RC AF Fairen, AG Dohm, JM Baker, VR de Pablo, MA Ruiz, J Ferris, JC Anderson, RC TI Episodic flood inundations of the northern plains of Mars SO ICARUS LA English DT Review DE Mars; Tharsis floods; oceans; lakes ID PATHFINDER LANDING SITE; MARTIAN IMPACT CRATERS; COLD-CLIMATE FEATURES; ALTIMETER MOLA DATA; HEMISPHERIC DICHOTOMY; CHAOTIC OBLIQUITY; TECTONIC ACTIVITY; OUTFLOW CHANNELS; THAUMASIA REGION; FLUVIAL VALLEYS AB Throughout the recorded history of Mars, liquid water has distinctly shaped its landscape, including the prominent circum-Chryse and the northwestern slope valleys outflow channel systems, and the extremely flat northern plains topography at the distal reaches of these outflow channel systems. Paleotopographic reconstructions of the Tharsis magmatic complex reveal the existence of an Europe-sized Noachian drainage basin and subsequent aquifer system in eastern Tharsis. This basin is proposed to have sourced outburst floodwaters that sculpted the outflow channels, and ponded to form various hypothesized oceans, seas, and lakes episodically through time. These floodwaters decreased in volume with time due to inadequate groundwater recharge of the Tharsis aquifer system. Martian topography, as observed from the Mars Orbiter Laser Altimeter, corresponds well to these ancient flood inundations, including the approximated shorelines that have been proposed for the northern plains. Stratigraphy, geomorphology. and topography record at least one great Noachian-Early Hesperian northern plains ocean. a Late Hesperian sea inset within the margin of the high water marks of the previous ocean, and a number of widely distributed minor lakes that may represent a reduced Late Hesperian sea, or ponded waters in the deepest reaches of the northern plains related to minor Tharsis- and Elysium-induced Amazonian flooding. (C) 2003 Elsevier Inc. All rights reserved. C1 Univ Autonoma Madrid, CSIC, CBM, E-28049 Madrid, Spain. Univ Complutense Madrid, Seminar Planetary Sci, E-28040 Madrid, Spain. Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ Rey Juan Carlos, ESCET, Madrid 28933, Spain. Univ Complutense Madrid, Dept Geodinam, E-28040 Madrid, Spain. US Geol Survey, Denver, CO 80225 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Fairen, AG (reprint author), Univ Autonoma Madrid, CSIC, CBM, E-28049 Madrid, Spain. RI Dohm, James/A-3831-2014; de Pablo, Miguel Angel/J-6442-2014; Ruiz, Javier/P-3975-2015 OI de Pablo, Miguel Angel/0000-0002-4496-2741; Ruiz, Javier/0000-0002-3937-8380 NR 132 TC 117 Z9 118 U1 2 U2 20 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD SEP PY 2003 VL 165 IS 1 BP 53 EP 67 DI 10.1016/S0019-1035(03)00144-1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 721VB UT WOS:000185338200005 ER PT J AU Hofstadter, MD Butler, BJ AF Hofstadter, MD Butler, BJ TI Seasonal change in the deep atmosphere of Uranus SO ICARUS LA English DT Article DE Uranus; giant planet; microwave ID THERMAL STRUCTURE; INFRARED OBSERVATIONS; JOVIAN PLANETS; ENERGY-BALANCE; URANIAN SYSTEM; GIANT PLANETS; TEMPERATURE; MODEL; VARIABILITY; AMMONIA AB We present high-resolution radio maps of Uranus, made from data collected in 1994 at wavelengths of 2 and 6 cm, which show large-scale changes occurring deep and rapidly in the troposphere. Brightness features in these maps are significantly different from those observed throughout the 1980's. These differences are not due to the changing viewing geometry, but result from atmospheric changes in the 5 to 50 bar region. All the observations show strong latitudinal variations in absorber abundance and/or temperature, causing the South Pole to appear brighter than lower latitudes. The transition between bright pole and darker latitudes is always near -45degrees, but between 1989 and 1994 the contrast between the regions increased significantly. This suggests that the large-scale circulation in the upper 50 bars of the uranian Southern Hemisphere changed. Older, disk-averaged microwave observations have suggested that seasonal variability occurs, but these new maps are the first to provide detailed timing and location information which can be used to test dynamical models. (C) 2003 Elsevier Inc. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. RP Hofstadter, MD (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,Mail Stop 169-237, Pasadena, CA 91109 USA. NR 51 TC 19 Z9 19 U1 1 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD SEP PY 2003 VL 165 IS 1 BP 168 EP 180 DI 10.1016/S0019-1035(03)00174-X PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 721VB UT WOS:000185338200013 ER PT J AU Kelley, MS Vilas, F Gaffey, MJ Abell, PA AF Kelley, MS Vilas, F Gaffey, MJ Abell, PA TI Quantified mineralogical evidence for a common origin of 1929 Kollaa with 4 Vesta and the HED meteorites SO ICARUS LA English DT Article DE asteroids; Vesta; surfaces; asteroids; asteroids, composition; spectroscopy ID ASTEROID FAMILIES; PARENT BODY; SPECTRA; EUCRITE AB In this paper, we present the first correlation of derived mineral abundances of V-class Asteroid 1929 Kollaa, 4 Vesta, and the HED meteorites. We demonstrate that 1929 Kollaa has a basaltic composition consistent with an origin within the crustal layer of 4 Vesta, and show a plausible genetic connection between Kollaa and the cumulate eucrite meteorites. These data support the proposed delivery mechanism of HED meteorites to the Earth from Vesta, and provide the first mineralogical constraint derived from the observation of a small V-class, Vesta family asteroid on the crustal thickness of 4 Vesta. (C) 2003 Elsevier Inc. All rights reserved. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ N Dakota, Dept Space Studies, Grand Forks, ND 58202 USA. Rensselaer Polytech Inst, Dept Earth & Environm Sci, Troy, NY 12180 USA. RP Kelley, MS (reprint author), Georgia So Univ, Dept Geog & Geol, Statesboro, GA 30460 USA. NR 25 TC 27 Z9 27 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD SEP PY 2003 VL 165 IS 1 BP 215 EP 218 DI 10.1016/S0019-1035(03)00149-0 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 721VB UT WOS:000185338200016 ER PT J AU Dempsey, PJ Handschuh, RF Afjeh, AA AF Dempsey, PJ Handschuh, RF Afjeh, AA TI Decision fusion analysis detects spiral bevel gear damage SO IEEE AEROSPACE AND ELECTRONIC SYSTEMS MAGAZINE LA English DT Article AB A diagnostic tool for detecting damage to spiral bevel gears was developed. Two different monitoring technologies - oil debris analysis and vibration - were integrated using data fusion into a health monitoring system for detecting surface fatigue pitting damage on gears. This integrated system showed improved detection and decision-making capabilities as compared to using individual monitoring technologies. This diagnostic tool was evaluated by collecting vibration and oil debris data from fatigue tests performed in the NASA Glenn Spiral Bevel Gear Fatigue Rigs. Data was collected during experiments performed in this test rig when pitting damage occurred. Results show that combining the vibration and oil debris measurement technologies improves the detection of pitting damage on spiral bevel gears. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. USA, Res Lab, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Toledo, Toledo, OH 43606 USA. RP Dempsey, PJ (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 17 TC 2 Z9 2 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0885-8985 J9 IEEE AERO EL SYS MAG JI IEEE Aerosp. Electron. Syst. Mag. PD SEP PY 2003 VL 18 IS 9 BP 11 EP 17 DI 10.1109/MAES.2003.1232154 PG 7 WC Engineering, Aerospace; Engineering, Electrical & Electronic SC Engineering GA 718DR UT WOS:000185130300002 ER PT J AU Lux, J AF Lux, J TI Comparison of relative energies and powers SO IEEE INSTRUMENTATION & MEASUREMENT MAGAZINE LA English DT Editorial Material C1 Jet Prop Lab, Spacecraft Telecommun Sect, Pasadena, CA 91125 USA. RP Lux, J (reprint author), Jet Prop Lab, Spacecraft Telecommun Sect, Pasadena, CA 91125 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1094-6969 J9 IEEE INSTRU MEAS MAG JI IEEE Instrum. Meas. Mag. PD SEP PY 2003 VL 6 IS 3 BP 66 EP 68 DI 10.1109/MIM.2003.1238359 PG 3 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 723FQ UT WOS:000185422200010 ER PT J AU Filman, RE AF Filman, RE TI End-to-end over interplanetary networks SO IEEE INTERNET COMPUTING LA English DT Editorial Material ID ARGUMENTS C1 NASA, Res Inst Adv Comp Sci, Ames, IA USA. RP Filman, RE (reprint author), NASA, Res Inst Adv Comp Sci, Ames, IA USA. NR 3 TC 10 Z9 10 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1089-7801 J9 IEEE INTERNET COMPUT JI IEEE Internet Comput. PD SEP-OCT PY 2003 VL 7 IS 5 BP 4 EP 5 PG 2 WC Computer Science, Software Engineering SC Computer Science GA 721KB UT WOS:000185314600001 ER PT J AU Simon, MK Alouini, MS AF Simon, MK Alouini, MS TI Probability of error for noncoherent M-ary orthogonal FSK with postdetection switched combining SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article DE M-ary frequency shift keying; M-ary noncoherent orthogonal modulation; postdetection diversity; switched combining ID DIVERSITY SYSTEMS; SELECTION DIVERSITY; CHANNELS AB This letter extends the notion of postdetection switched combining previously introduced by the authors to M-ary orthogonal modulation and proceeds to analyze and evaluate its average bit-error rate performance for. the dual-branch case. The particular variation chosen for the switching strategy uses a different model than that previously used for the binary case and although it results in a slightly poorer performance, it nevertheless outperforms conventional (predetection) switched combining for all values of M. Results are obtained for a variety of popular channel models including Rayleigh, Rician, and Nakagami-m fading. Because, of its relative simplicity of implementation, the proposed scheme once again offers a very attractive low-complexity solution for mitigating the deleterious effects of multipath fading. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. RP Simon, MK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 16 Z9 16 U1 1 U2 2 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 SEP PY 2003 VL 51 IS 9 BP 1456 EP 1462 DI 10.1109/TCOMM.2003.816968 PG 7 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 723EB UT WOS:000185418500010 ER PT J AU Alouini, MS Simon, MK AF Alouini, MS Simon, MK TI Postdetection switched combining - A simple diversity scheme with improved BER performance SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article; Proceedings Paper CT 36th Annual Conference on Information Sciences and Systems (CISS) CY MAR, 2002 CL PRINCETON, NEW JERSEY DE diversity combining; fading channels; postdetection diversity and switched combining ID SELECTION DIVERSITY; FADING CHANNELS; SYSTEMS AB This paper develops, analyzes, and optimizes a simpler form of dual-branch switch-and-stay combining (SSC), namely, one that relies on the output signal plus noise rather than the instantaneous signal-to-noise ratio (SNR) to trigger the switching between the diversity branches. Analysis supported by numerical results show that the newly proposed postdetection SSC scheme outperforms predetection SSC and this performance gain increases as the channel conditions improve in terms of average SNR and/or severity of fading. In brief, when simplicity of implementation is of primary concern, as is the case, for example, in mobile units, the proposed scheme offers an attractive low-complexity solution to mitigate the deleterious effects of multipath fading. C1 Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Alouini, MS (reprint author), Univ Minnesota, Dept Elect & Comp Engn, Minneapolis, MN 55455 USA. NR 19 TC 29 Z9 29 U1 1 U2 2 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 SEP PY 2003 VL 51 IS 9 BP 1591 EP 1602 DI 10.1109/TCOMM.2003.816952 PG 12 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 723EB UT WOS:000185418500024 ER PT J AU Brandon, EJ Wesseling, EE Chang, V Kuhn, WB AF Brandon, EJ Wesseling, EE Chang, V Kuhn, WB TI Printed microinductors on flexible substrates for power applications SO IEEE TRANSACTIONS ON COMPONENTS AND PACKAGING TECHNOLOGIES LA English DT Article DE inductor; integrated passive components; power electronics; printed electronics ID FERRITE COMPOSITE-MATERIALS; COMPLEX PERMEABILITY; FREQUENCY DISPERSION; ZN FERRITE; RUBBER COMPOSITE; PLANAR INDUCTORS; LOW-TEMPERATURE; FABRICATION; PERMITTIVITY; CORE AB A low-profile microinductor was fabricated on a copper-clad polyimide substrate where the current carrying coils were patterned from the existing metallization layer and the magnetic core was printed using a magnetic ceramic-polymer composite material. Highly loaded ferrite-polymer composite materials were formulated, yielding adherent films with 4piM(s) approximate to 3900 G at +5000 Oe applied dc field. These composite magnetic films combine many of the superior properties of high temperature ceramic magnetic materials with the inherent processibility of polymer thick films. Processing temperatures for the printed films were between 100 degreesC and 130 degreesC, facilitating integration with a wide range of substrates and components. The quality factor of the microinductor was found to peak at Q = 18.5 near 10 MHz, within the optimal frequency range for power applications. A flat, nearly frequency independent inductance of 1.33 muH was measured throughout this frequency range for a 5 mm x 5 mm component, with a dc resistance of 2.6 Omega and a resonant frequency of 124 MHz. The combination of printed ceramic composites with organic/polymer substrates enables new methods for embedding passive components and ultimately the integration of high Q inductors with standard integrated circuits for low profile power electronics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Kansas State Univ, Manhattan, KS 66506 USA. RP Brandon, EJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 43 TC 25 Z9 26 U1 0 U2 9 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1521-3331 J9 IEEE T COMPON PACK T JI IEEE Trans. Compon. Packaging Technol. PD SEP PY 2003 VL 26 IS 3 BP 517 EP 523 DI 10.1109/TCAPT.2003.817641 PG 7 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA 729BY UT WOS:000185752200003 ER PT J AU Durden, SL AF Durden, SL TI Airborne polarimetric radar measurements of rainfall profiles SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE differential phase; ku-band radar; polarization; precipitation; reflectivity ID SIZE DISTRIBUTION; PRECIPITATION; RETRIEVAL AB This work reports airborne Ku-band dual-polarization measurements of precipitation, acquired in three hurricanes during the Third Convection and Moisture Experiment (CAMEX-3) in 1998. Dual-polarization signatures in intense convective rain are seen at incidence angles as small as 20degrees off nadir. Dual-polarization rain estimates using the specific propagation differential phase shift are compared with single-polarization rain profiling algorithm results. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Durden, SL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 12 TC 2 Z9 2 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD SEP PY 2003 VL 41 IS 9 BP 2125 EP 2127 DI 10.1109/TGRS.2003.817208 PN 2 PG 3 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 723EL UT WOS:000185419400003 ER PT J AU Hernandez-Pajares, M Zornoza, JMJ Subirana, JS Colombo, OL AF Hernandez-Pajares, M Zornoza, JMJ Subirana, JS Colombo, OL TI Feasibility of wide-area subdecimeter navigation with GALILEO and modernized GPS SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE ambiguity resolution; carrier-phase; differential global positioning system (DGPS); GALILEO; global navigation satellite system (GNSS); kinematic global positioning system; navigation; wide area ID IONOSPHERIC DETERMINATION AB Precise corrections with, A three-dimensional voxel model of the ionosphere based on global navigation satellite system (GNSS) data from a wide-area network of ground receivers can help resolve differential cairrier-phase ambiguities over very long baselines of hundreds of kilometers in present two-frequency systems [global positioning system (GPS) and global orbiting navigation satellite system (GLONASS)] or in planned three-frequency systems (GALILEO, Modernized GPS). A study based on simulated three-frequency data from A modified GNSS signal generator indicates that all the Phase Ambiguities could be resolved successfully more than 90% of the time. This' should be useful in surveying large areas with instruments that require Very precise geolocation (e.g;, radar or Lidar altimetry, interferometric synthetic aperture radar, interferometric sonar, etc.). C1 Univ Politecn Catalunya, Res Grp Astron & Geomat, Barcelona, Spain. NASA, Goddard Space Flight Ctr, Goddard Earth & Space Technol Ctr, Greenbelt, MD 20771 USA. RP Hernandez-Pajares, M (reprint author), Univ Politecn Catalunya, Res Grp Astron & Geomat, Barcelona, Spain. RI Sanz Subirana, Jaume/C-1265-2014; Juan Zornoza, Jose Miguel/S-6224-2016 OI Sanz Subirana, Jaume/0000-0001-8880-7084; Juan Zornoza, Jose Miguel/0000-0003-1126-2367 NR 13 TC 14 Z9 14 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD SEP PY 2003 VL 41 IS 9 BP 2128 EP 2131 DI 10.1109/TGRS.2003.817209 PN 2 PG 4 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 723EL UT WOS:000185419400004 ER PT J AU Holliday, J Steinke, R Agrawal, D El Abbadi, A AF Holliday, J Steinke, R Agrawal, D El Abbadi, A TI Epidemic algorithms for replicated databases SO IEEE TRANSACTIONS ON KNOWLEDGE AND DATA ENGINEERING LA English DT Article DE database replication; distributed databases; epidemic communication ID SYSTEM AB We present a family of epidemic algorithms for maintaining replicated database systems. The algorithms are based on the causal delivery of log records where each record corresponds to one transaction instead of one operation. The first algorithm in this family is a pessimistic protocol that ensures serializability and guarantees strict executions. Since we expect the epidemic algorithms to be used in environments with low probability of conflicts among transactions, we develop a variant of the pessimistic algorithm which is optimistic in that transactions commit as soon as they terminate locally and inconsistencies are detected asynchronously as the effects of committed transactions propagate through the system. The last member of the family of epidemic algorithms is pessimistic and uses voting with quorums to resolve conflicts and improve transaction response time. A simulation study evaluates the performance of the protocols. C1 Santa Clara Univ, Dept Comp Engn, Santa Clara, CA 95053 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Santa Barbara, Dept Comp Sci, Santa Barbara, CA 93106 USA. RP Holliday, J (reprint author), Santa Clara Univ, Dept Comp Engn, Santa Clara, CA 95053 USA. NR 35 TC 26 Z9 27 U1 0 U2 2 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1041-4347 J9 IEEE T KNOWL DATA EN JI IEEE Trans. Knowl. Data Eng. PD SEP-OCT PY 2003 VL 15 IS 5 BP 1218 EP 1238 DI 10.1109/TKDE.2003.1232274 PG 21 WC Computer Science, Artificial Intelligence; Computer Science, Information Systems; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 716TY UT WOS:000185046300012 ER PT J AU Weller, RA Ryle, WT Newton, AT McMahon, MD Miller, TM Magruder, RH AF Weller, RA Ryle, WT Newton, AT McMahon, MD Miller, TM Magruder, RH TI A technique for producing ordered arrays of metallic nanoclusters by electroless deposition in focused ion beam patterns SO IEEE TRANSACTIONS ON NANOTECHNOLOGY LA English DT Article DE electroless deposition; focused ion beam; nanocrystal arrays; nanotechnology ID NANOPARTICLES; GOLD AB Ordered arrays of An nanoclusters have been prepared on Si substrates using a combination of focused ion beam (FIB) surface processing and electroless deposition. Particles varying in size from approximately 30 to 100 nm have been produced in regular grid patterns whose geometry is controlled to high precision by the FIB. Potential applications range from engineering of the surface plasmon resonance for numerous optical applications to building structures for tethering organic molecules in specific geometric arrangements. C1 Vanderbilt Univ, Dept Elect Engn & Comp Sci, Nashville, TN 37235 USA. Western Kentucky Univ, Bowling Green, KY 42101 USA. Vanderbilt Univ, Dept Biomed Engn, Nashville, TN 37235 USA. Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA. Vanderbilt Univ, Dept Mech Engn, Nashville, TN 37235 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Belmont Univ, Dept Phys, Nashville, TN 37212 USA. RP Weller, RA (reprint author), Vanderbilt Univ, Dept Elect Engn & Comp Sci, 221 Kirkland Hall, Nashville, TN 37235 USA. RI McMahon, Matthew/F-2986-2013 NR 17 TC 10 Z9 10 U1 0 U2 8 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1536-125X J9 IEEE T NANOTECHNOL JI IEEE Trans. Nanotechnol. PD SEP PY 2003 VL 2 IS 3 BP 154 EP 157 DI 10.1109/TNANO.2003.817528 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Science & Technology - Other Topics; Materials Science; Physics GA 719TA UT WOS:000185219600006 ER PT J AU Huntsberger, T Pirjanian, P Trebi-Ollennu, A Das Nayar, H Aghazarian, H Ganino, AJ Garrett, M Joshi, SS Schenker, PS AF Huntsberger, T Pirjanian, P Trebi-Ollennu, A Das Nayar, H Aghazarian, H Ganino, AJ Garrett, M Joshi, SS Schenker, PS TI CAMPOUT: A control architecture for tightly coupled coordination of multirobot systems for planetary surface exploration SO IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART A-SYSTEMS AND HUMANS LA English DT Article DE distributed control architecture; multiple mobile robots; robot outposts; tight coordination ID BEHAVIOR-BASED CONTROL; ROBOT NAVIGATION; MOBILE ROBOT; COOPERATION AB Exploration of high risk terrain areas such as cliff faces and site construction operations by autonomous robotic systems on Mars requires a control architecture that is able to autonomously adapt to uncertainties in knowledge of the environment. We report on the development of a software/hardware framework for cooperating multiple robots performing such tightly coordinated tasks. This work builds on our earlier research into autonomous planetary rovers and robot arms. Here, we seek to closely coordinate the mobility and manipulation of multiple robots to perform examples of a cliff traverse for science data acquisition, and site construction operations including grasping, hoisting, and transport of extended objects such as large array sensors over natural, unpredictable terrain. In support of this work we have developed an enabling distributed control architecture called control architecture for multirobot planetary outposts (CAMPOUT) wherein integrated multirobot mobility and control mechanisms are derived as group compositions and coordination of more basic behaviors under a task-level multiagent planner. CAMPOUT includes the necessary group behaviors and communication mechanisms for coordinated/cooperative control of heterogeneous robotic platforms. In this paper, we describe CAMPOUT, and its application to ongoing physical experiments with multirobot systems at the Jet Propulsion Laboratory in Pasadena, CA, for exploration of cliff faces and deployment of extended payloads. C1 Jet Propuls Lab, Pasadena, CA 91109 USA. Evolut Robot Inc, Pasadena, CA 91103 USA. OphirTech, Altadena, CA 91003 USA. Univ Calif Davis, Dept Mech & Aeronaut Engn, Davis, CA 95616 USA. RP Jet Propuls Lab, Pasadena, CA 91109 USA. EM Terry.Huntsberger@jpl.nasa.gov; paolo@evolution.com; hafi@ophirtech.com; maejoshi@uc-davis.edu NR 62 TC 68 Z9 70 U1 0 U2 28 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1083-4427 EI 1558-2426 J9 IEEE T SYST MAN CY A JI IEEE Trans. Syst. Man Cybern. Paart A-Syst. Hum. PD SEP PY 2003 VL 33 IS 5 BP 550 EP 559 DI 10.1109/TSMCA.2003.817398 PG 10 WC Computer Science, Cybernetics; Computer Science, Theory & Methods SC Computer Science GA 744GC UT WOS:000186618700002 ER PT J AU Bao, XQ Bar-Cohen, Y Chang, ZS Dolgin, BP Sherrit, S Pal, DS Du, S Peterson, T AF Bao, XQ Bar-Cohen, Y Chang, ZS Dolgin, BP Sherrit, S Pal, DS Du, S Peterson, T TI Modeling and computer simulation of ultrasonic/sonic driller/corer (USDC) SO IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL LA English DT Article AB Simulation and analytical models for the ultrasonic/sonic drill/corer (USDC) are described in this paper. The USDC was developed as a tool for in-situ rock sampling and analysis in support of the NASA planetary exploration program. The USDC uses a novel drive mechanism, which transfers ultrasonic vibrations of a piezoelectric actuator into larger oscillations of a free-flying mass (free-mass). The free-mass impact on the drill bit creates a stress pulse at the drill tip/rock interface causing fracture in the rock. The main parts of the device (transducer, free-mass, bit, and rock) and the interactions between them were analyzed and numerically modeled to explore the drive mechanism. Each of these interactions is normally described by a time-dependent 2- or 3-D model involving slowly converging solutions, which makes the conventional approach unsuitable for USDC optimization studies. A simplified integrated model using tabulated data was developed to simulate the operation of the USDC on desktop PC and successfully predicted the characteristics of the device under a variety of conditions. The simulated results of the model and the experimental data used to verify the model are presented. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Cyberson Inc, Erie, PA 16510 USA. RP Bao, XQ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 8 TC 63 Z9 72 U1 2 U2 20 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0885-3010 J9 IEEE T ULTRASON FERR JI IEEE Trans. Ultrason. Ferroelectr. Freq. Control PD SEP PY 2003 VL 50 IS 9 BP 1147 EP 1160 DI 10.1109/TUFFC.2003.1235326 PG 14 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA 724ZX UT WOS:000185519100007 PM 14561031 ER PT J AU Simon, MK Alouini, MS AF Simon, MK Alouini, MS TI Some new results for integrals involving the generalized marcum Q function and their application to performance evaluation over fading channels (vol 2, pg 611, 2003) SO IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS LA English DT Correction C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Minnesota, Dept Elect Engn, Minneapolis, MN 55455 USA. RP Simon, MK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 2 TC 0 Z9 0 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1536-1276 J9 IEEE T WIREL COMMUN JI IEEE Trans. Wirel. Commun. PD SEP PY 2003 VL 2 IS 5 BP 1108 EP 1108 DI 10.1109/TWC.2003.817580 PG 1 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 721JF UT WOS:000185312700026 ER PT J AU Osmundson, JS Michael, JB Machniak, MJ Grossman, MA AF Osmundson, JS Michael, JB Machniak, MJ Grossman, MA TI Quality management metrics for software development SO INFORMATION & MANAGEMENT LA English DT Article DE metrics; software management; software process AB It can be argued that the quality of software management has an effect on the degree of success or failure of a software development program. We have developed a metric for measuring the quality of software management along four dimensions: requirements management, estimation/planning management, people management, and risk management. The quality management metric (QMM) for a software development program manager is a composite score obtained using a questionnaire administered to both the program manager and a sample of his or her peers. The QMM is intended to both characterize the quality of software management and serve as a template for improving software management performance. We administered the questionnaire to measure the performance of managers responsible for large software development programs within the US Department of Defense (DOD). Informal verification and validation of the metric compared the QMM score to an overall program-success score for the entire program; this resulted in a positive correlation. (C) 2002 Elsevier Science B.V. All rights reserved. C1 USN, Postgrad Sch, Dept Comp Sci, CS MJ, Monterey, CA 93943 USA. USN, Postgrad Sch, Dept Informat Sci, CC OS, Monterey, CA 93943 USA. Space & Naval Warfare Syst Ctr, San Diego, CA 92152 USA. NASA, Dryden Flight Res Ctr, Edwards AFB, CA 93523 USA. RP Michael, JB (reprint author), USN, Postgrad Sch, Dept Comp Sci, CS MJ, 833 Dyer Rd, Monterey, CA 93943 USA. NR 25 TC 21 Z9 24 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-7206 J9 INFORM MANAGE-AMSTER JI Inf. Manage. PD SEP PY 2003 VL 40 IS 8 BP 799 EP 812 AR PII S0378-7206(02)00114-3 DI 10.1016/S0378-7206(02)00114-3 PG 14 WC Computer Science, Information Systems; Information Science & Library Science; Management SC Computer Science; Information Science & Library Science; Business & Economics GA 716WW UT WOS:000185053400007 ER PT J AU Chattopadhyay, G Maiwald, F Schlecht, E Dengler, RJ Pearson, JC Mehdi, I AF Chattopadhyay, G Maiwald, F Schlecht, E Dengler, RJ Pearson, JC Mehdi, I TI Spurious signal response of broadband solid-state frequency multipliers at millimeter and submillimeter wavelengths SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article DE spurious signals; frequency multipliers; millimeter and submillimeter wavelengths ID THZ; MIXERS AB Heterodyne instruments at millimeter and submillimeter wavelengths often use wideband fixed-tuned frequency multipliers, in conjunction with broadband power amplifiers driven by frequency synthesizers, as the local oscillator (LO) source. At these frequencies the multipliers use Gallium Arsenide (GaAs) based Schottky varactor diodes as the nonlinear element, and like most other harmonic generators are susceptible to spurious signal interference. The state-of-the-art LO sources at these wavelengths use high power MMIC amplifiers at the initial stages, and are used to drive the subsequent multiplier stages to have enough LO power to pump the mixers. Because of the high input power environment and the presence of noise in the system, the multipliers become vulnerable to spurious signal interference. As the spurious signals propagate through the receiver system, they generate inter-modulation products which might fall in the passband of the heterodyne instrument and seriously degrade its performance. In this paper spurious signal response of solid-state frequency multipliers at millimeter and submillimeter wavelengths is investigated. Results of numerical harmonic balance simulations and laboratory experiments, which were found to show good agreement, are presented here. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. RP Chattopadhyay, G (reprint author), CALTECH, Jet Prop Lab, 329-47 Caltech, Pasadena, CA 91125 USA. NR 22 TC 3 Z9 3 U1 0 U2 1 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-9271 J9 INT J INFRARED MILLI JI Int. J. Infrared Millimeter Waves PD SEP PY 2003 VL 24 IS 9 BP 1485 EP 1498 DI 10.1023/A:1025587825833 PG 14 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 717QH UT WOS:000185100500007 ER PT J AU Pandey, RB Gettrust, JF Seyfarth, R Cueva-Parra, LA AF Pandey, RB Gettrust, JF Seyfarth, R Cueva-Parra, LA TI Self-organized phase segregation in a driven flow of dissimilar particles mixtures SO INTERNATIONAL JOURNAL OF MODERN PHYSICS C LA English DT Article DE self-organized pattern; layering; phase separation; lattice gas ID SYSTEMS AB Self-organized patterns in an immiscible fluid mixture of dissimilar particles driven from a source at the bottom are examined as a function of hydrostatic pressure bias by a Monte Carlo computer simulation. As the upward pressure bias competes with sedimentation due to gravity, a multi-phase system emerges: a dissociating solid phase from the source is separated from a migrating gas phase towards the top by an interface of mixed (bicontinuous) phase. Scaling of solid-to-gas phase with the altitude is nonuniversal and depends on both the range of the height/depth and the magnitude of the pressure bias. Onset of phase separation and layering is pronounced at low bias range. C1 USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. Univ So Mississippi, Dept Phys & Astron, Hattiesburg, MS 39406 USA. Univ So Mississippi, Dept Comp Sci & Stat, Hattiesburg, MS 39406 USA. RP Pandey, RB (reprint author), USN, Res Lab, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. NR 23 TC 8 Z9 8 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0129-1831 J9 INT J MOD PHYS C JI Int. J. Mod. Phys. C PD SEP PY 2003 VL 14 IS 7 BP 955 EP 962 DI 10.1142/S0129183103005108 PG 8 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 763CV UT WOS:000188055400009 ER PT J AU Pikuta, EV Hoover, RB Bej, AK Marsic, D Whitman, WB Cleland, D Krader, P AF Pikuta, EV Hoover, RB Bej, AK Marsic, D Whitman, WB Cleland, D Krader, P TI Desulfonatronum thiodismutans sp nov., a novel alkaliphilic, sulfate-reducing bacterium capable of lithoautotrophic growth SO INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY LA English DT Article ID RENATURATION RATES; METABOLISM; LAKE; DNA AB A novel alkaliphilic, sulfate-reducing bacterium, strain MLF1(T), was isolated from sediments of soda Mono Lake, California. Gram-negative vibrio-shaped cells were observed, which were 0.6-0.7 x 1.2-2.7 mum in size, motile by a single polar flagellum and occurred singly, in pairs or as short spirilla. Growth was observed at 15-48 degreesC (optimum, 37 degreesC) > 1-7 % NaCl, w/v (optimum, 3 %) and pH 8.0-10.0 (optimum, 9.5). The novel isolate is strictly alkaliphilic, requires a high concentration of carbonate in the growth medium and is obligately anaerobic and catalasenegative. As electron donors, strain MLIF1(T) uses hydrogen, formate and ethanol. Sulfate, sulfite and thiosulfate (but not sulfur or nitrate) can be used as electron acceptors. The novel isolate is a lithoheterotroph and a facultative lithoautotroph that is able to grow on hydrogen without an organic source of carbon. Strain MLF1(T) is resistant to kanamycin and gentamicin, but sensitive to chloramphenicol and tetracycline. The DNA G + C content is 63.0 mol% (HPLC). DNA-DNA hybridization with the most closely related species, Desulfonatronum lacustre Z-7951(T), exhibited 51 % homology. Also, the genome size (11.6 x 109 Da) and T-m value of the genomic DNA (71 +/- 2 degreesC) for strain MLF1(T) were significantly different from the genome size (2.1 x 109 Da) and T-m value (63 +/- 2 degreesC) for Desulfonatronum lacustre Z-7951(T). On the basis of physiological and molecular properties, the isolate was considered to be a novel species of the genus Desulfonatronum, for which the name Desulfonatronum thiodismutans sp. nov. is proposed (the type strain is MLF1(T) =ATCC BAA-395(T) = DSM 14708(T)). C1 NASA, NSSTC, Astrobiol Lab, Huntsville, AL 35805 USA. Univ Alabama, Dept Biol, Birmingham, AL 35294 USA. Univ Alabama, Dept Biol Sci, MSB, Huntsville, AL 35899 USA. Univ Alabama, Struct Biol Lab, MSB, Huntsville, AL 35899 USA. Univ Georgia, Dept Microbiol, Athens, GA 30602 USA. Amer Type Culture Collect, Manassas, VA 20110 USA. RP Pikuta, EV (reprint author), NASA, NSSTC, Astrobiol Lab, 320 Sparkman Dr, Huntsville, AL 35805 USA. RI Marsic, Damien/A-1087-2009 OI Marsic, Damien/0000-0003-0847-8095 NR 27 TC 60 Z9 65 U1 0 U2 7 PU SOC GENERAL MICROBIOLOGY PI READING PA MARLBOROUGH HOUSE, BASINGSTOKE RD, SPENCERS WOODS, READING RG7 1AG, BERKS, ENGLAND SN 1466-5026 J9 INT J SYST EVOL MICR JI Int. J. Syst. Evol. Microbiol. PD SEP PY 2003 VL 53 BP 1327 EP 1332 DI 10.1099/ijs.0.02598-0 PN 5 PG 6 WC Microbiology SC Microbiology GA 725PG UT WOS:000185551100016 PM 13130014 ER PT J AU Pikuta, E Cleland, D Tang, J AF Pikuta, E Cleland, D Tang, J TI Aerobic growth of Anoxybacillus pushchinoensis K1(T) : Emended descriptions of A-pushchinoensis and the genus Anoxybacillus SO INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY LA English DT Article AB In this work, corrections are made to the descriptions of the species Anoxybacillus pushchinoensis corrig. and the genus Anoxybacillus. Experiments to determine the relationship of A. pushchinoensis K1(T) to oxygen showed that it was capable of aerobic growth, but preferred to grow anaerobically. During aerobic growth, the redox indicator resazurin was reduced as a result of hydrogen gas production. The facultatively anaerobic nature of K1(T) was ascertained by cultivation in aerobic liquid medium, where growth began at the bottom of the tube. The anaerobic nature of K1(T) was also indicated by a negative catalase reaction. This work is submitted to correct the description of the species A. pushchinoensis from obligate anaerobe to aerotolerant anaerobe and to emend the description of the genus Anoxybacillus from obligate anaerobes or facultative anaerobes to aerotolerant anaerobes or facultative anaerobes. C1 NASA, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. Amer Type Culture Collect, Manassas, VA 20110 USA. RP Pikuta, E (reprint author), NASA, Natl Space Sci & Technol Ctr, SD-50,320 Sparkman Dr, Huntsville, AL 35805 USA. NR 3 TC 30 Z9 30 U1 0 U2 3 PU SOC GENERAL MICROBIOLOGY PI READING PA MARLBOROUGH HOUSE, BASINGSTOKE RD, SPENCERS WOODS, READING RG7 1AG, BERKS, ENGLAND SN 1466-5026 J9 INT J SYST EVOL MICR JI Int. J. Syst. Evol. Microbiol. PD SEP PY 2003 VL 53 BP 1561 EP 1562 DI 10.1099/ijs.0.02643-0 PN 5 PG 2 WC Microbiology SC Microbiology GA 725PG UT WOS:000185551100050 PM 13130048 ER PT J AU Zak, M AF Zak, M TI Quantum algorithms in Hilbert database SO INTERNATIONAL JOURNAL OF THEORETICAL PHYSICS LA English DT Article DE quantum algorithms; Hilbert database AB A fast quantum algorithm for a search and pattern recognition in a Hilbert space memory structure is proposed. All the memory information is mapped onto a unitary operator acting upon a quantum state which represents a piece of information to be retrieved. As a result of only one quantum measurement, the address of the required information encoded in a number of the corresponding row of the unitary matrix is determined. By combining direct and dot products, the dimensionality of the memory space can be made exponentially large, using only linear resources. However, since the preprocessing, i.e., mapping the memory information into a Hilbert space can appear to be exponentially expensive, the proposed algorithm will be effective for NASA applications when the preprocessing is implemented on the ground, while the memory search is performed on remote objects. C1 CALTECH, Jet Prop Lab, Ultracomp Grp, Pasadena, CA 91125 USA. Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN USA. RP Zak, M (reprint author), CALTECH, Jet Prop Lab, Ultracomp Grp, Pasadena, CA 91125 USA. NR 2 TC 1 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0020-7748 J9 INT J THEOR PHYS JI Int. J. Theor. Phys. PD SEP PY 2003 VL 42 IS 9 BP 2061 EP 2068 DI 10.1023/A:1027339220458 PG 8 WC Physics, Multidisciplinary SC Physics GA 740AZ UT WOS:000186379800010 ER PT J AU Gilat, A Goldberg, RK Roberts, GD AF Gilat, A Goldberg, RK Roberts, GD TI High strain rate response of epoxy in tensile and shear loading SO JOURNAL DE PHYSIQUE IV LA English DT Article; Proceedings Paper CT 7th Internatioanl Conference on Mechanical and Physical Behaviour of Materials Under Dynamic Loading CY SEP 08-12, 2003 CL OPORTO, PORTUGAL AB Epoxy type E-862 has been tested in tension and shear over a wide range of strain rates from 10(-4) to 700 s(-1). Experiments at strain rates of up to 2 s(-1) have been conducted with a hydraulic testing machine, and tests at strain rates above 300 s(-1) have been conducted using the split Hopkinson bar technique. The results show that the epoxy is very sensitive to the rate of deformation. A stiffer material response (increase in modulus) is observed with increasing strain rate in both tension and shear loadings. The maximum stress also increases with increasing strain rate. The maximum shear stress at a strain rate of 700 s(-1) is roughly twice the maximum stress at a strain rate of 10(-4) s(-1). In the tensile tests a smaller increase in the maximum stress is observed. This, however, might be due to the existence of a hydrostatic stress component that causes a premature fracture of the specimens. C1 Ohio State Univ, Dept Mech Engn, Columbus, OH 43210 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Gilat, A (reprint author), Ohio State Univ, Dept Mech Engn, 206 W 18th Ave, Columbus, OH 43210 USA. NR 6 TC 9 Z9 9 U1 1 U2 2 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 1155-4339 J9 J PHYS IV JI J. Phys. IV PD SEP PY 2003 VL 110 BP 123 EP 127 DI 10.1051/jp4:20030681 PG 5 WC Physics, Multidisciplinary SC Physics GA 725NZ UT WOS:000185550400022 ER PT J AU Cole, SR Noll, TE Perry, B AF Cole, SR Noll, TE Perry, B TI Transonic dynamics tunnel aeroelastic testing in support of aircraft development SO JOURNAL OF AIRCRAFT LA English DT Article C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Cole, SR (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 40 TC 5 Z9 6 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD SEP-OCT PY 2003 VL 40 IS 5 BP 820 EP 831 DI 10.2514/2.6873 PG 12 WC Engineering, Aerospace SC Engineering GA 730WN UT WOS:000185853300003 ER PT J AU Schuster, DM Liu, DD Huttsell, LJ AF Schuster, DM Liu, DD Huttsell, LJ TI Computational aeroelasticity: Success, progress, challenge SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA Dynamics Specialists Conference CY APR, 2003 CL NORFOLK, VIRGINIA SP Amer Inst Aeronaut & Astronaut ID EULER EQUATIONS; FIGHTER C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Arizona State Univ, Tempe, AZ 85287 USA. USAF, Res Lab, Wright Patterson AFB, OH 45433 USA. RP Schuster, DM (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 54 TC 39 Z9 49 U1 0 U2 6 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD SEP-OCT PY 2003 VL 40 IS 5 BP 843 EP 856 DI 10.2514/2.6875 PG 14 WC Engineering, Aerospace SC Engineering GA 730WN UT WOS:000185853300005 ER PT J AU Dowell, E Edwards, J Strganac, T AF Dowell, E Edwards, J Strganac, T TI Nonlinear aeroelasticity SO JOURNAL OF AIRCRAFT LA English DT Review ID LIMIT-CYCLE OSCILLATIONS; ANGLE-OF-ATTACK; UNSTEADY AERODYNAMICS; TYPICAL SECTION; ACTIVE CONTROL; WING SECTION; FLUTTER; AIRFOIL; STABILITY; BEHAVIOR C1 Duke Univ, Durham, NC 27708 USA. NASA, Langley Res Ctr, Langley, VA 23681 USA. Texas A&M Univ, College Stn, TX 77843 USA. RP Dowell, E (reprint author), Duke Univ, Durham, NC 27708 USA. NR 116 TC 140 Z9 157 U1 6 U2 29 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD SEP-OCT PY 2003 VL 40 IS 5 BP 857 EP 874 DI 10.2514/2.6876 PG 18 WC Engineering, Aerospace SC Engineering GA 730WN UT WOS:000185853300006 ER PT J AU Levy, DW Zickuhr, T Wahls, RA Pirzadeh, S Hemsch, MJ AF Levy, DW Zickuhr, T Wahls, RA Pirzadeh, S Hemsch, MJ TI Data summary from the first AIAA Computational Fluid Dynamics Drag Prediction Workshop SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA 40th Aerospace Sciences Meeting CY JAN 14-18, 2002 CL RENO, NEVADA SP Amer Inst Aeronaut & Astronaut AB The results from the first AIAA Computational Fluid Dynamics (CFD) Drag Prediction Workshop are summarized. The workshop was designed specifically to assess the state of the art of CFD methods for force and moment prediction. An impartial forum was provided to evaluate the effectiveness of existing computer codes and modeling techniques and to identify areas needing additional research and development. The subject of the study was the German Aerospace Research Center DLR-F4 wing-body configuration, which is representative of transport aircraft designed for transonic flight. Specific test cases were required so that valid comparisons could be made. Optional test cases included constant C-L drag-rise predictions, typically used in airplane design by industry. Results are compared to experimental data from three wind-tunnel tests. A total of 18 international participants using 14 different codes submitted data to the workshop. No particular grid type or turbulence model was more accurate, when compared to each other, or to wind tunnel data. Most of the results overpredicted C-L0 and C-D0, but induced drag (dC(D)/dC(L)(2)) agreed fairly well. Drag rise at high Mach number was underpredicted, however, especially at high CL. On average, the drag data were fairly accurate, but the scatter was greater than desired. The results show that well-validated Reynolds averaged Navier-Stokes CFD methods are sufficiently accurate to make design decisions based on predicted drag. C1 Cessna Aircraft Co, Wichita, KS 67215 USA. Boeing Co, Long Beach, CA 92647 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Levy, DW (reprint author), Cessna Aircraft Co, Wichita, KS 67215 USA. NR 8 TC 28 Z9 32 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD SEP-OCT PY 2003 VL 40 IS 5 BP 875 EP 882 DI 10.2514/2.6877 PG 8 WC Engineering, Aerospace SC Engineering GA 730WN UT WOS:000185853300007 ER PT J AU Taylor, DM Lin, KY AF Taylor, DM Lin, KY TI Aging effects on the interlaminar shear strength of high-performance composites SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 42nd Structures, Structural Dynamics, and Materials Conference CY APR 16-19, 2001 CL SEATTLE, WASHINGTON SP Amer Inst Aeronaut & Astronaut, ASME, ASCE, AHS, ASC AB The effect of isothermal aging on interlaminar shear strengths of quasi-isotropic composites laminates were evaluated by using ASTM D 3846-94, Standard Test Method for In-Plane Shear Strength of Reinforced Plastics. Thermoset bismaleimide (IM7/5260) and thermoplastic polyimide (IM7/K3B) were investigated to determine the aging degradation in different matrix materials. The laminates were 24 plies and had a lay up of [-45/90/45/0]3S. Aging temperatures were 300,350, and 400degreesF and aging time varied from a few hours to 28 months. Nonaged specimens were also tested for baseline values. Significant differences were noted between these two different matrices. Isothermal aging for IM7/5260 initially caused postcuring effects prior to an overall decrease in interlaminar shear strength. Strength degradation was directly dependent on both aging temperatures and times. In addition, accelerated aging effects at 400degreesF were observed. For the IM7/K3B specimens no postcure effects were observed. The interlaminar shear strength decreased for longer aging times, but showed little variation for different temperatures. Aging at 400degreesF did not show any accelerated aging effects. The interlaminar shear strength results were compared with previously obtained compression after impact data. Similar trends in strength degradation were observed. C1 Univ Washington, Seattle, WA 98195 USA. RP Taylor, DM (reprint author), NASA, Lyndon B Johnson Space Ctr, M-C ES2, Houston, TX 77058 USA. NR 7 TC 3 Z9 3 U1 2 U2 4 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0021-8669 J9 J AIRCRAFT JI J. Aircr. PD SEP-OCT PY 2003 VL 40 IS 5 BP 971 EP 976 DI 10.2514/2.6882 PG 6 WC Engineering, Aerospace SC Engineering GA 730WN UT WOS:000185853300019 ER PT J AU Graves, SS Burner, AW Edwards, JW Schuster, DM AF Graves, SS Burner, AW Edwards, JW Schuster, DM TI Dynamic deformation measurements of an aeroelastic semispan model SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA 19th Applied Aerodynamics Conference CY JUN 11-14, 2001 CL ANAHEIM, CALIFORNIA SP Amer Inst Aeronaut & Astronaut ID FIGHTER AB The techniques used to acquire, reduce, and analyze dynamic deformation measurements of an aeroelastic semispan wind-tunnel model are presented. Single-camera, single-view video photogrammetry (also referred to as videogrammetric model deformation) was used to determine dynamic aeroelastic deformation of the semispan "models for aeroelastic validation research involving computation" model in the Transonic Dynamics Tunnel at NASA Langley Research Center. Dynamic deformation was determined from optical retroreflective tape targets at five semispan locations located on the wing from the root to the tip. Digitized video images from a charge-coupled device camera were recorded and processed to determine automatically target image plane locations that were then corrected for instrumentation errors. Videogrammetric dynamic data were acquired at a 60-Hz rate for time records of up to 6 s during portions of a flutter/limit-cycle oscillation test at Mach numbers from 0.3 to 0.96. Spectral analysis of the deformation data were used to identify dominant frequencies in the wing motion. The dynamic data will be used in future studies to separate aerodynamic and structural effects and to provide time history deflection data for computational aeroelasticity code evaluation and validation. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Graves, SS (reprint author), NASA, Langley Res Ctr, Mail Stop 236, Hampton, VA 23681 USA. NR 8 TC 9 Z9 10 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 SEP-OCT PY 2003 VL 40 IS 5 BP 977 EP 984 DI 10.2514/2.6883 PG 8 WC Engineering, Aerospace SC Engineering GA 730WN UT WOS:000185853300020 ER PT J AU Jensen, MP Del Genio, AD AF Jensen, MP Del Genio, AD TI Radiative and microphysical characteristics of deep convective systems in the tropical western Pacific SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID RADAR REFLECTIVITY; CLOUD CLUSTERS; CIRRUS CLOUDS; ATMOSPHERIC RADIATION; HEATING RATES; WARM POOL; THUNDERSTORM; SCATTERING; RAINFALL; CLIMATE AB The radiative and microphysical characteristics of 17 precipitating systems observed by the Tropical Rainfall Measuring Mission (TRMM) satellite over Manus, Papua New Guinea, and Nauru Island are modeled. These cases represent both deep and midlevel convection. Reflectivity data from the TRMM precipitation radar and Geostationary Meteorological Satellite infrared radiometer measurements are used to parameterize the three-dimensional cloud microphysics of each precipitating cloud system. These parameterized cloud properties are used as input for a two-stream radiative transfer model. Comparisons with measurements of broadband radiative fluxes at the top of atmosphere and the surface show agreement to within 20%. In cases in which the convective available potential energy (CAPE) is large, deep convective clouds with extended anvil decks form, containing layers of ice crystals that are too small to be detected by the TRMM radar but have a large optical thickness. This results in maximum shortwave heating and longwave cooling near cloud top at heights of 12-14 km. When CAPE is small, convective clouds extend only to midlevels (4-7 km), and there are no cloud layers below the detectability limit of the TRMM radar. Radiative heating and cooling in these cases are maximum near the freezing level. A sensitivity analysis suggests that the small ice crystals near the cloud top and larger precipitation-sized particles play equally significant roles in producing the high albedos of tropical anvil clouds. A comparison of the radiative heating profiles calculated in this study with latent heating profiles from previous studies shows that for cases of mature deep convection near local solar noon, the maximum radiative heating is 10%-30% of the magnitude of the maximum latent heating. C1 Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Jensen, MP (reprint author), Columbia Univ, NASA, Goddard Inst Space Studies, Armstrong Hall,2880 Broadway, New York, NY 10025 USA. RI Del Genio, Anthony/D-4663-2012 OI Del Genio, Anthony/0000-0001-7450-1359 NR 33 TC 17 Z9 18 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD SEP PY 2003 VL 42 IS 9 BP 1234 EP 1254 DI 10.1175/1520-0450(2003)042<1234:RAMCOD>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 717KR UT WOS:000185088100004 ER PT J AU Holley, DC DeRoshia, CW Moran, MM Wade, CE AF Holley, DC DeRoshia, CW Moran, MM Wade, CE TI Chronic centrifugation (hypergravity) disrupts the circadian system of the rat SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE circadian rhythm; body temperature; locomotor activity; rhythm splitting ID SUPRACHIASMATIC NUCLEI; BODY-TEMPERATURE; THERMOREGULATORY RESPONSES; BIOLOGICAL RHYTHMS; CLOCK; LIGHT; PERFORMANCE; MONKEYS AB The present study was conducted to evaluate the response of rat deep body temperature (DBT) and gross locomotor activity (LMA) circadian rhythms to acute hypergravity onset and adaptation to chronic ( 14 day) hypergravity exposure over three gravity intensities (1.25, 1.5, and 2 G). Centrifugation of unanesthetized naive animals resulted in a dramatic acute decrease in DBT (-1.45, -2.40, and -3.09 degreesC for the 1.25, 1.5, and 2.0 G groups, respectively). LMA was suppressed for the duration of centrifugation ( vs. control period); the percent decrease for each group on days 12 - 14, respectively, was 1.0 G, - 15.2%, P = not significant; 1.25 G, - 26.9%, P < 0.02; 1.5 G, - 44.5%, P < 0.01; and 2.0 G, - 63.1%, P < 0.002. The time required for DBT and LMA circadian rhythmic adaptation and stabilization to hypergravity onset increased from 1.25 to 2.0 G in all circadian metrics except daily means. Periodicity analysis detected the phenomenon of circadian rhythm splitting, which has not been reported previously in response to chronic hypergravity exposure. Our analysis documents the disruptive and dose-dependent effects of hypergravity on circadian rhythmicity and the time course of adaptation to 14-day chronic centrifugation exposure. C1 San Jose State Univ, Dept Biol Sci, San Jose, CA 95192 USA. NASA, Div Life Sci, Ames Res Ctr, Moffett Field, CA 94035 USA. RP San Jose State Univ, Dept Biol Sci, 1 Washington Sq, San Jose, CA 95192 USA. EM dholley@email.sjsu.edu NR 55 TC 12 Z9 14 U1 0 U2 1 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 EI 1522-1601 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD SEP PY 2003 VL 95 IS 3 BP 1266 EP 1278 DI 10.1152/japplphysiol.00707.2002 PG 13 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 711HP UT WOS:000184733800045 PM 12794036 ER PT J AU Gillette, JM Globus, R Nielsen-Preiss, SM AF Gillette, JM Globus, R Nielsen-Preiss, SM TI Annexin 2 and lipid raft involvement in osteoblastic mineralization. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract CT 25th Annual Meeting of the American-Society-for-Bone-and-Mineral-Research CY SEP 19-23, 2003 CL MINNEAPOLIS, MINNESOTA SP Amer Soc Bone Mineral Res C1 Univ Colorado, Ctr Hlth Sci, Denver, CO USA. NASA Ames Res Ctr, Gravitat Res Branch, Moffett Field, CA USA. Univ Colorado, Hlth Sci Ctr, Denver, CO USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2003 VL 18 SU 2 BP S228 EP S228 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 734WG UT WOS:000186080500903 ER PT J AU Globus, RK Amblard, D Nishimura, Y Litzenberger, J Corcoran, ML Almeida, EAC Wade, CE Morey-Holton, E Damsky, CD Kim, JB Wronski, TJ Iwaniec, UT van der Meulen, MCH AF Globus, RK Amblard, D Nishimura, Y Litzenberger, J Corcoran, ML Almeida, EAC Wade, CE Morey-Holton, E Damsky, CD Kim, JB Wronski, TJ Iwaniec, UT van der Meulen, MCH TI Skeletal responses to altered loading of growing transgenic mice that express a function-perturbing form of beta-1 integrin in osteoblasts. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract CT 25th Annual Meeting of the American-Society-for-Bone-and-Mineral-Research CY SEP 19-23, 2003 CL MINNEAPOLIS, MINNESOTA SP Amer Soc Bone Mineral Res C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. Univ Florida, Gainesville, FL USA. Cornell Univ, Ithaca, NY USA. RI van der Meulen, Marjolein/D-1549-2010 OI van der Meulen, Marjolein/0000-0001-6637-9808 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2003 VL 18 SU 2 BP S134 EP S134 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 734WG UT WOS:000186080500523 ER PT J AU Morey-Holton, EM Garetto, LP Doty, SB Halloran, BP Turner, RT AF Morey-Holton, EM Garetto, LP Doty, SB Halloran, BP Turner, RT TI Is animal age a factor in the response of bone to spaceflight? SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract CT 25th Annual Meeting of the American-Society-for-Bone-and-Mineral-Research CY SEP 19-23, 2003 CL MINNEAPOLIS, MINNESOTA SP Amer Soc Bone Mineral Res C1 NASA Ames Res Ctr, Moffett Field, CA USA. Indiana Univ, Sch Dent, Indianapolis, IN USA. Indiana Univ, Sch Med, Indianapolis, IN USA. Hosp Special Surg, New York, NY USA. Univ Calif San Francisco, Vet Affairs Med Ctr, San Francisco, CA 94143 USA. Mayo Fdn, Rochester, MN USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2003 VL 18 SU 2 BP S219 EP S219 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 734WG UT WOS:000186080500869 ER PT J AU Parra, M Vercoutere, W Roden, C Banerjee, I Krauser, W Holton, E Searby, N Globus, R Almeida, E AF Parra, M Vercoutere, W Roden, C Banerjee, I Krauser, W Holton, E Searby, N Globus, R Almeida, E TI Hypergravity stimulates the extracellular Matrix/Integrin-Signaling axis and proliferation in primary osteoblasts. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract CT 25th Annual Meeting of the American-Society-for-Bone-and-Mineral-Research CY SEP 19-23, 2003 CL MINNEAPOLIS, MINNESOTA SP Amer Soc Bone Mineral Res C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, Astrobiol Inst, Moffett Field, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2003 VL 18 SU 2 BP S133 EP S133 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 734WG UT WOS:000186080500519 ER PT J AU Venton, LL Evans, G Holton, E Hill, E Turner, R Wronski, T Bikle, D Halloran, BP AF Venton, LL Evans, G Holton, E Hill, E Turner, R Wronski, T Bikle, D Halloran, BP TI The effectiveness of osmotic mini-pumps to deliver fluorochrome labels in rats. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract CT 25th Annual Meeting of the American-Society-for-Bone-and-Mineral-Research CY SEP 19-23, 2003 CL MINNEAPOLIS, MINNESOTA SP Amer Soc Bone Mineral Res C1 Vet Affairs Med Ctr, Div Endocrinol, San Francisco, CA USA. Mayo Clin & Mayo Fdn, Rochester, MN 55905 USA. NASA, Ames Res Ctr, Moffett Field, CA USA. Lockheed Martin Space Operat, Moffett Field, CA USA. Univ Florida, Dept Physiol Sci, Gainesville, FL USA. Univ Calif San Francisco, Vet Affairs Med Ctr, Dept Med, San Francisco, CA 94143 USA. Univ Calif San Francisco, Vet Affairs Med Ctr, Dept Physiol, Div Endocrinol, San Francisco, CA 94143 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2003 VL 18 SU 2 BP S220 EP S220 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 734WG UT WOS:000186080500871 ER PT J AU Perlwitz, J Harnik, N AF Perlwitz, J Harnik, N TI Observational evidence of a stratospheric influence on the troposphere by planetary wave reflection SO JOURNAL OF CLIMATE LA English DT Article ID NORTHERN-HEMISPHERE WINTER; ARCTIC OSCILLATION; CLIMATE VARIABILITY; GEOPOTENTIAL HEIGHT; GREENHOUSE-GAS; ANNULAR MODES; PROPAGATION; WEATHER; OZONE; CIRCULATION AB Recent studies have pointed out the impact of the stratosphere on the troposphere by dynamic coupling. In the present paper, observational evidence for an effect of downward planetary wave reflection in the stratosphere on Northern Hemisphere tropospheric waves is given by combining statistical and dynamical diagnostics. A time-lagged singular value decomposition analysis is applied to daily tropospheric and stratospheric height fields recomposed for a single zonal wavenumber. A wave geometry diagnostic for wave propagation characteristics that separates the index of refraction into vertical and meridional components is used to diagnose the occurrence of reflecting surfaces. For zonal wavenumber 1, this study suggests that there is one characteristic configuration of the stratospheric jet that reflects waves back into the troposphere - when the polar night jet peaks in the high-latitude midstratosphere. This configuration is related to the formation of a reflecting surface for vertical propagation at around 5 hPa as a result of the vertical curvature of the zonal-mean wind and a clear meridional waveguide in the lower to middle stratosphere that channels the reflected wave activity to the high-latitude troposphere. C1 Columbia Univ, NASA, Goddard Inst Space Studies, Ctr Climate Syst Res, New York, NY 10025 USA. Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY USA. RP Perlwitz, J (reprint author), Columbia Univ, NASA, Goddard Inst Space Studies, Ctr Climate Syst Res, 2880 Broadway, New York, NY 10025 USA. RI Perlwitz, Judith/B-7201-2008 OI Perlwitz, Judith/0000-0003-4061-2442 NR 43 TC 115 Z9 124 U1 1 U2 16 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0894-8755 J9 J CLIMATE JI J. Clim. PD SEP PY 2003 VL 16 IS 18 BP 3011 EP 3026 DI 10.1175/1520-0442(2003)016<3011:OEOASI>2.0.CO;2 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 720BV UT WOS:000185241900005 ER PT J AU Cronin, MF Xie, SP Hashizume, H AF Cronin, MF Xie, SP Hashizume, H TI Barometric pressure variations associated with Eastern Pacific tropical instability waves SO JOURNAL OF CLIMATE LA English DT Article ID SEA-SURFACE TEMPERATURE; ATMOSPHERIC BOUNDARY-LAYER; EQUATORIAL PACIFIC; OCEAN; FRONT; VARIABILITY; WIND; CLOUDINESS; DYNAMICS; CURRENTS AB Barometric pressure, surface temperature, and wind time series in the eastern equatorial Pacific are analyzed to determine if oceanic tropical instability wave (TIW) sea surface temperature variations cause barometric pressure gradients large enough to influence the atmospheric boundary layer. During the study period from April 2001 to September 2002, 11 TIWs propagated westward past 110degreesW, causing a spectral peak at 20 - 30 days in the sea surface temperature (SST) meridional difference between 2degreesN, 110degreesW and 0degrees, 110degreesW. Likewise, the meridional pressure difference also had a spectral peak in the 20 - 30- day TIW band. Cross-spectral analysis shows that within the TIW band, SST-induced pressure variations were roughly -0.1 hPa degreesC(-1) in magnitude. The resulting pressure gradient force is comparable in magnitude to other terms in the meridional momentum balance. Implications about the role of the boundary layer capping in the adjustment to SST forcing are discussed. C1 NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Hawaii Manoa, Int Pacific Res Ctr, Honolulu, HI 96822 USA. Univ Hawaii Manoa, Dept Meteorol, Honolulu, HI 96822 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. RP Cronin, MF (reprint author), NOAA, Pacific Marine Environm Lab, 7600 Sand Point Way NE, Seattle, WA 98115 USA. RI Xie, Shang-Ping/C-1254-2009 OI Xie, Shang-Ping/0000-0002-3676-1325 NR 28 TC 36 Z9 36 U1 0 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 SEP PY 2003 VL 16 IS 18 BP 3050 EP 3057 DI 10.1175/1520-0442(2003)016<3050:BPVAWE>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 720BV UT WOS:000185241900008 ER PT J AU Sarabia, SF Sipes, WE Putcha, L AF Sarabia, SF Sipes, WE Putcha, L TI Validation of a handheld computer-based performance test battery for pharmacodynamic assessment of neuro-active drugs SO JOURNAL OF CLINICAL PHARMACOLOGY LA English DT Meeting Abstract CT 32nd Annual Meeting of the American-College-of-Clinical-Pharmacology CY SEP 21-23, 2003 CL TAMPA, FLORIDA SP Amer Coll Clin Pharmacol C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Wyle Labs Life Sci Syst & Serv Div, Houston, TX USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 0091-2700 J9 J CLIN PHARMACOL JI J. Clin. Pharmacol. PD SEP PY 2003 VL 43 IS 9 MA 98 BP 1037 EP 1037 PG 1 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 714PA UT WOS:000184921600092 ER PT J AU Park, HG Zak, M AF Park, HG Zak, M TI Gray-box approach for fault detection of dynamical system SO JOURNAL OF DYNAMIC SYSTEMS MEASUREMENT AND CONTROL-TRANSACTIONS OF THE ASME LA English DT Article AB We present a fault detection method called the gray-box. The term "gray-box" refers to the approach wherein a deterministic model of system, i.e., "white box, " is used to filter the data and generate a residual, while a stochastic model, i.e., "black-box" is used to describe the residual. The residual is described by a three-tier stochastic model. An auto-regressive process, and a time-delay feed-forward neural network describe the linear and nonlinear components of the residual, respectively. The last component, the noise, is characterized by its moments. Faults are detected by monitoring the parameters of the auto-regressive model, the weights of the neural network, and the moments of noise. This method is demonstrated on a simulated system of a gas turbine with time delay feedback actuator. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Park, HG (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 5 Z9 5 U1 0 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0022-0434 J9 J DYN SYST-T ASME JI J. Dyn. Syst. Meas. Control-Trans. ASME PD SEP PY 2003 VL 125 IS 3 BP 451 EP 454 DI 10.1115/1.1589032 PG 4 WC Automation & Control Systems; Instruments & Instrumentation SC Automation & Control Systems; Instruments & Instrumentation GA 728JP UT WOS:000185714300020 ER PT J AU Einstein, GO McDaniel, MA Williford, CL Pagan, JL Dismukes, RK AF Einstein, GO McDaniel, MA Williford, CL Pagan, JL Dismukes, RK TI Forgetting of intentions in demanding situations is rapid SO JOURNAL OF EXPERIMENTAL PSYCHOLOGY-APPLIED LA English DT Article ID SHORT-TERM-MEMORY; ADULT AGE-DIFFERENCES; WORKING-MEMORY; IMPLEMENTATION INTENTIONS; CAPACITY; RETENTION; REHEARSAL; INTERRUPTION; PERFORMANCE; ACTIVATION AB Demanding work settings often require the deferral of intended actions. In 3 experiments, participants were to withhold a response until they encountered a task change (which occurred 5, 15, or 40 s later). To approximate highly demanding settings, the experimenters sometimes divided attention during the delay period. During some of the delays the experimenters interrupted the participants with an additional task (Experiment 1). Demanding conditions as well as interruptions revealed rapid forgetting of intentions at levels that would be considered significant in applied settings. Experiments 2 and 3 showed that this rapid forgetting was not reduced by strategic rehearsal and implementation intention strategies. The results suggest that maintaining intentions over brief delays is not a trivial task for the human cognitive system. C1 Furman Univ, Dept Psychol, Greenville, SC 29613 USA. Univ New Mexico, Dept Psychol, Albuquerque, NM 87131 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Einstein, GO (reprint author), Furman Univ, Dept Psychol, Greenville, SC 29613 USA. NR 59 TC 93 Z9 95 U1 0 U2 11 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 SEP PY 2003 VL 9 IS 3 BP 147 EP 162 DI 10.1037/1076-898X.9.3.147 PG 16 WC Psychology, Applied SC Psychology GA 734CN UT WOS:000186037800001 PM 14570509 ER PT J AU Dansby, MY Bovell-Benjamin, AC AF Dansby, MY Bovell-Benjamin, AC TI Physical properties and sixth graders' acceptance of an extruded ready-to-eat sweetpotato breakfast cereal SO JOURNAL OF FOOD SCIENCE LA English DT Article DE bulk density; expansion ratio; water absorption index; consumer testing; extruded sweetpotato breakfast cereal ID EXTRUSION PROCESS PARAMETERS; SINGLE-SCREW EXTRUSION; PROXIMATE COMPOSITION; YOUNG-CHILDREN; SOY FLOUR; QUALITY; MOISTURE; STORAGE; PREFERENCES; ATTRIBUTES AB Extruded ready-to-eat breakfast cereals (RTEBCs) were made from varying levels of sweetpotato flour (SPF), whole-wheat bran (WWB), and extrusion cooking. Moisture, protein, and ash contents were lower in the 100% SPF than the 100% WWB. Carbohydrate, beta-carotene, and ascorbic acid contents were higher in the 100% SPF. Fat, thiamin, riboflavin contents, bulk densities, and the water absorption index were similar for the cereals. However, the expansion ratio was highest in the 100% SPF cereal. The 100% WWB had the lightest color and most fibrous morphology. Extruded RTEBC containing 100% SPF and 75%/25% SPF/WWB were well-liked and acceptable to sixth graders attending an elementary school in Auburn, Alabama, but the 100% WWB was unacceptable. C1 Tuskegee Univ, NASA, Tuskegee Ctr Environm Syst & Human Explorat Space, Dept Nutr & Food Sci, Tuskegee, AL 36088 USA. S Carolina State Univ, Orangeburg, SC 29117 USA. RP Bovell-Benjamin, AC (reprint author), Tuskegee Univ, NASA, Tuskegee Ctr Environm Syst & Human Explorat Space, Dept Nutr & Food Sci, Tuskegee, AL 36088 USA. NR 45 TC 8 Z9 9 U1 1 U2 4 PU INST FOOD TECHNOLOGISTS PI CHICAGO PA 525 WEST VAN BUREN, STE 1000, CHICAGO, IL 60607-3814 USA SN 0022-1147 J9 J FOOD SCI JI J. Food Sci. PD SEP PY 2003 VL 68 IS 8 BP 2607 EP 2612 DI 10.1111/j.1365-2621.2003.tb07069.x PG 6 WC Food Science & Technology SC Food Science & Technology GA 739ZV UT WOS:000186377100035 PM 14719527 ER PT J AU Mukhopadhyay, V AF Mukhopadhyay, V TI Historical perspective on analysis and control of aeroelastic responses SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Review ID ACTIVE CONTROL TECHNOLOGY; INTEGRATED AEROSERVOELASTIC OPTIMIZATION; FLEXIBLE WING PROGRAM; CONSTRAINED OPTIMIZATION; FLUTTER SUPPRESSION; CONTROL SURFACES; SPECIAL SECTION; STORE FLUTTER; TUNNEL MODEL; FLIGHT C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Mukhopadhyay, V (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 162 TC 71 Z9 83 U1 3 U2 14 PU AMER INST AERONAUTICS ASTRONAUTICS PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0731-5090 EI 1533-3884 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD SEP-OCT PY 2003 VL 26 IS 5 BP 673 EP 684 DI 10.2514/2.5108 PG 12 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 721EZ UT WOS:000185305200001 ER PT J AU Park, SY Mazanek, DD AF Park, SY Mazanek, DD TI Mission functionality for deflecting earth-crossing asteroids/comets SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article AB A detailed optimization problem is formulated to calculate optimal impulses for deflecting Earth-crossing asteroids/comets,using nonlinear programming. The constrained optimization problem is based on a three-dimensional patched conic method to include the Earth's gravitational effects and the asteroid/comet's orbital inclination. The magnitudes and impulse angles of optimal DeltaV are accurately computed at various points on the asteroid/comet's orbit to provide a given target separation distance. Interceptor mass (or energy) is estimated for various deflection strategies such as high-thrust engine, kinetic deflection, nuclear detonation, and laser ablation. The potential ability of each mitigation scheme, in conjunction with several future spacecraft concepts, is also described. The optimal DeltaV and deflection strategy are dependent on the size and the orbital elements of the asteroid/comet, as well as the amount of warning time. C1 Yonsei Univ, Ctr Astrodynam & Space Technol, Dept Astron, Seoul 120749, South Korea. NASA, Langley Res Ctr, Spacecraft & Sensors Branch, Hampton, VA 23681 USA. RP Park, SY (reprint author), Yonsei Univ, Ctr Astrodynam & Space Technol, Dept Astron, Seoul 120749, South Korea. RI Park, Sang-Young/F-5989-2013 NR 21 TC 11 Z9 11 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD SEP-OCT PY 2003 VL 26 IS 5 BP 734 EP 742 DI 10.2514/2.5128 PG 9 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 721EZ UT WOS:000185305200008 ER PT J AU Myung, NV Park, DY Yoo, BY Sumodjo, PTA AF Myung, NV Park, DY Yoo, BY Sumodjo, PTA TI Development of electroplated magnetic materials for MEMS SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE magnetic films; electrodeposition; soft magnetic materials; hard magnetic materials; co-based alloys; MEMS/NEMS ID THIN-FILMS; ELECTRODEPOSITION; MICROACTUATION; ANISOTROPY; COERCIVITY AB Permalloy (19%Ni-81%Fe alloy) and nickel have thus far found the most utility in magnetic-Micro Electro Mechanical Systems (MEMS), because the technologies necessary for depositing and micromachining them have been well-developed previously by the data storage industry. However, other high performance soft magnetic materials and hard magnetic materials have unique advantages that are driving their integration with MEMS/NEMS. These include enhanced magnetic properties, corrosion resistance, electrical resistivity, and reduced films stress. The primary issues associated with the integration of these magnetic materials in MEMS/NEMS are discussed. (C) 2003 Elsevier Science B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, MEMS Technol Grp, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Chem Engn, Los Angeles, CA 90095 USA. RP Myung, NV (reprint author), CALTECH, Jet Prop Lab, MEMS Technol Grp, 4800 Oak Grove,Mail Stop 302-306, Pasadena, CA 91109 USA. RI Sumodjo, Paulo Teng An/F-2049-2014; Institute of Chemistry - USP, Dept. of Chemistry/B-8988-2012 NR 33 TC 123 Z9 127 U1 4 U2 33 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 SEP PY 2003 VL 265 IS 2 BP 189 EP 198 DI 10.1016/S0304-8853(03)00264-6 PG 10 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 717ZF UT WOS:000185120100013 ER PT J AU Guo, G Yang, P Hu, YX Winker, D Hostetler, CA Baum, BA Reichardt, J AF Guo, G Yang, P Hu, YX Winker, D Hostetler, CA Baum, BA Reichardt, J TI Manifestations of interference fluctuations of phase functions and backscattering cross sections for ice crystals with specific orientations SO JOURNAL OF OPTICS A-PURE AND APPLIED OPTICS LA English DT Article DE phase interference; scattering; ice crystals ID DIFFERENCE TIME-DOMAIN; LIGHT-SCATTERING; OPTICAL-PROPERTIES; CIRRUS CLOUDS; T-MATRIX; PARTICLES; DIFFRACTION; CYLINDERS AB The ray-by-ray integration technique is applied to investigate the effect of the phase interference between rays on the scattering phase functions and backscattering cross sections of pristine hexagonal ice plates and columns with specific orientations. Numerical computations are carried but at 0.532 and 1.064 mum wavelengths. The results demonstrate that strong fluctuations of the phase function as a function of scattering angle are inherent for oriented particles. In addition, constructive fluctuation patterns are noted for particle backscattering cross sections, and are a function of particle size. These fluctuations, which are absent from the conventional ray-tracing computations, are caused by phase interference. C1 Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Maryland, Joint Ctr Earth Syst Technol, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Yang, P (reprint author), Texas A&M Univ, Dept Atmospher Sci, TAMU 3150, College Stn, TX 77843 USA. RI Yang, Ping/B-4590-2011; Baum, Bryan/B-7670-2011; Hu, Yongxiang/K-4426-2012 OI Baum, Bryan/0000-0002-7193-2767; NR 32 TC 2 Z9 2 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 1464-4258 J9 J OPT A-PURE APPL OP JI J. Opt. A-Pure Appl. Opt. PD SEP PY 2003 VL 5 IS 5 BP 520 EP 527 AR PII S1464-4258(03)60867-6 DI 10.1088/1464-4258/5/5/314 PG 8 WC Optics SC Optics GA 729GJ UT WOS:000185764600015 ER PT J AU Chernov, AA AF Chernov, AA TI Step bunching and solution flow SO JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS LA English DT Article; Proceedings Paper CT Romanian Conference on Advanced Materials (ROCAM 2003) CY SEP 15-18, 2003 CL CONSTANTA, ROMANIA SP Minist Educ, Res & Youth, Romanian Acad, Univ Bucharest, Fac Phys & Credis Dept, Ovidius Univ, Constanta, Romanian Mat Sci, Crystal Growth Soc, Natl Inst Mat Phys, Bucharest, Natl Inst R&D Optoelect, Bucharest, ICPE DE crystal growth; step bunching; defects; turbulent solution flow ID PHASE-SHIFTING INTERFEROMETRY; CRYSTAL-GROWTH; VICINAL FACE; MORPHOLOGICAL STABILITY; SURFACES; KINETICS; KDP; INSTABILITIES; MACROSTEPS; MOTION AB Some general unresolved problems of crystal growth from solution are briefly mentioned in Secs 1 and 2. Sec 3 presents the basic physical reasons for step bunching on a growing vicinal crystal surface in presence of solution flow. In Sec 4, influence of turbulent solution flow on an average steady state bunch width is discussed. The model takes into account the fact that solution flowing over a step bunch is depleted because of higher step density within the bunch. The solution depleted by this denser step train is dragged by the flow and simultaneously expands due to turbulent diffusion into the viscous sublayer adjacent to the growing crystal surface up to the boundary between the sublayer and bulk turbulent flow. Time required for this diffusion multiplied by the solution rate at the sublayer external boundary provides an estimate for the limiting length Lambda over which a step density perturbation influences solution concentration down the stream. Thus, finite thickness of the viscous sublayer determines typical bunch width Lambda, similar to nu/u(tau) along the solution flow, where nu is solution viscosity and u(tau) is friction velocity of the turbulent flow. This estimate is in reasonable agreement with the experiment, but full scale solution is still a challenge. C1 NASA, George C Marshall Space Flight Ctr, BAE Syst N Amer, Huntsville, AL 35812 USA. RP Chernov, AA (reprint author), NASA, George C Marshall Space Flight Ctr, BAE Syst N Amer, Mail Code SD46,MSFC, Huntsville, AL 35812 USA. NR 48 TC 7 Z9 9 U1 0 U2 2 PU NATL INST OPTOELECTRONICS PI BUCHAREST-MAGURELE PA 1 ATOMISTILOR ST, PO BOX MG-5, BUCHAREST-MAGURELE 76900, ROMANIA SN 1454-4164 J9 J OPTOELECTRON ADV M JI J. Optoelectron. Adv. Mater. PD SEP PY 2003 VL 5 IS 3 BP 575 EP 587 PG 13 WC Materials Science, Multidisciplinary; Optics; Physics, Applied SC Materials Science; Optics; Physics GA 722TH UT WOS:000185392400005 ER PT J AU Tew, RC Ibrahim, MB AF Tew, RC Ibrahim, MB TI Two-dimensional compressible non-acoustic modeling of stirling machine-type components SO JOURNAL OF PROPULSION AND POWER LA English DT Article AB Starting with an existing two-dimensional incompressible flow computer code, a two-dimensional code was developed for modeling enclosed gas volumes with oscillating boundaries. The incompressible code was modified to use compressible nonacoustic Navier-Stokes equations. The devices modeled have low Mach numbers and are sufficiently small that the time required for acoustics to propagate across the interiors is small compared to the cycle period. Therefore, acoustics were excluded to minimize computing time. The compressible nonacoustic assumptions are discussed. The governing equations are presented in transport equation format. The numerical methods are briefly described. Code predictions are compared with experimental data. Compressible nonacoustic predictions of gas spring losses agreed well with 10-rpm test data, and similar to50- and 500-rpm calculated and experimental pressure-volume diagrams agreed well. For a heat-exchanger/piston-cylinder test rig, calculations of heat exchanger heat fluxes at various axial locations over the cycle agreed well qualitatively with the data, but quantitative agreement was not good. C1 NASA, John H Glenn Res Ctr Lewis Field, Thermo Mech Syst Branch, Cleveland, OH 44135 USA. Cleveland State Univ, Fenn Coll Engn, Dept Mech Engn, Cleveland, OH 44115 USA. RP Tew, RC (reprint author), NASA, John H Glenn Res Ctr Lewis Field, Thermo Mech Syst Branch, Mail Stop 301-2,21000 Brookpark Rd, Cleveland, OH 44135 USA. NR 27 TC 2 Z9 2 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD SEP-OCT PY 2003 VL 19 IS 5 BP 922 EP 929 DI 10.2514/2.6185 PG 8 WC Engineering, Aerospace SC Engineering GA 726YU UT WOS:000185629800022 ER PT J AU Landis, GA Colozza, A LaMarre, CM AF Landis, GA Colozza, A LaMarre, CM TI Atmospheric flight on venus: A conceptual design SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article; Proceedings Paper CT AIAA 40th Aerospace Sciences Meeting CY JAN 14-18, 2002 CL RENO, NEVADA SP Amer Inst Aeronaut & Astronaut AB A solar-powered aircraft system is proposed for the exploration of Venus. The atmosphere of Venus provides several advantages for flying a solar-powered, aircraft. At the top of the cloud level, the solar intensity is comparable to or greater than terrestrial solar intensities. The atmospheric pressure makes flight much easier than on planets such as Mars. Also, the slow rotation of Venus allows an airplane to be designed for flight within continuous sunlight, eliminating the need for energy storage for nighttime flight. These factors make Venus a prime choice for a long-duration solar-powered aircraft. Fleets of solar-powered aircraft could provide an architecture for efficient and low-cost comprehensive coverage for a variety of scientific missions. C1 NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Illinois, Dept Aeronaut Engn, Champaign, IL 61820 USA. RP Landis, GA (reprint author), NASA, John H Glenn Res Ctr, Lewis Field,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 16 TC 12 Z9 12 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2003 VL 40 IS 5 BP 672 EP 677 DI 10.2514/2.6916 PG 6 WC Engineering, Aerospace SC Engineering GA 730XA UT WOS:000185854400009 ER PT J AU MacCormack, RW AF MacCormack, RW TI The effect of viscosity in hypervelocity impact cratering (Reprinted from AlAA Paper 69-354, 1969) SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Reprint AB A numerical method, of second order in both time and space, for the solution of the time-dependent compressible Navier-Stokes equations is presented. Conditions for stability are discussed. The method has been applied to calculate an axisymmetric flow field produced by hypervelocity impact. Results are given for impacts of aluminum cylinders (having diameters of 0.16, 0.32, and 0.64 cm) into aluminum targets. Viscosities of zero and 10(4) poise were assumed. Both plates and semi-infinite targets are considered at an impact speed of 10 km/sec. It is concluded that viscous effects become increasingly important as projectile size diminishes and cannot be neglected during the initial stages of crater formation for projectiles smaller than 0.5 cm in diameter. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP MacCormack, RW (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 18 TC 20 Z9 22 U1 2 U2 14 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2003 VL 40 IS 5 BP 757 EP 763 DI 10.2514/2.6901 PG 7 WC Engineering, Aerospace SC Engineering GA 730XA UT WOS:000185854400020 ER PT J AU Rakich, JV Cleary, JW AF Rakich, JV Cleary, JW TI Theoretical and experimental around inclined study of supersonic steady flow bodies of revolution (Reprinted from AIAA Journal, Vol. 8, No. 3, 1970, pp. 511-518) SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Reprint AB A three-dimensional method of characteristics is described and numerical results are critically assessed by comparison with the results of hypersonic wind-tunnel experiments. Calculations for a 15degrees half-angle sphere-cone have been performed for angles of attack up to alpha = 20degrees, and have been carried downstream 44 nose radii for alpha = 10degrees. Comparisons with pointed-cone calculations show that effects of bluntness persist at this distance. Pitot pressure distributions in the flowfield are in good agreement with experiment except on the leeward side of the body far from the nose, where low-energy, viscous fluid accumulates. The present calculations for 20degrees angle of attack indicate the formation of an embedded shock on the leeward side of the 15degrees sphere cone. Theoretical upwash angles around a Sears-Haack body are compared with classical slender body theory, indicating nonlinearities due to Mach number which may reduce the interference lift of wing-body combinations. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Rakich, JV (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 25 TC 0 Z9 0 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2003 VL 40 IS 5 BP 764 EP 771 DI 10.2514/2.6903 PG 8 WC Engineering, Aerospace SC Engineering GA 730XA UT WOS:000185854400021 ER PT J AU Marvin, JG AF Marvin, JG TI Turbulence Modeling for computational aerodynamics (Reprinted from AIAA Journal, Vol. 21, No. 7, 1983, pp. 941-955) SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Reprint ID BOUNDARY-LAYER INTERACTION; 3-DIMENSIONAL SHOCK-WAVE; HIGH REYNOLDS-NUMBER; TRANSONIC FLOW; CORNER C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Marvin, JG (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 115 TC 0 Z9 0 U1 0 U2 0 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 SEP-OCT PY 2003 VL 40 IS 5 BP 772 EP 786 DI 10.2514/2.6904 PG 15 WC Engineering, Aerospace SC Engineering GA 730XA UT WOS:000185854400022 ER PT J AU Moss, JN Bird, GA AF Moss, JN Bird, GA TI Direct simulation of transitional flow for hypersonic reentry conditions (Reprinted from AIAA paper 84-0223, Jan. 1984) SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Reprint ID MONTE-CARLO SIMULATION AB This paper presents results of flowfield calculations for typical hypersonic reentry conditions encountered by the nose region of the Space Shuttle Orbiter. Most of the transitional flow regime is covered by the altitude range of 150 to 92 km. Calculations were made with the Direct Simulation Monte Carlo (DSMC) method that accounts for translational, rotational, vibrational, and chemical nonequilibrium effects. Comparison of the DSMC heating results with both Shuttle flight data and continuum predictions showed good agreement at the lowest altitude considered. However, as the altitude increased, the continuum predictions, which did not include slip effects, departed rapidly from the DSMC results by overpredicting both heating and drag., The results demonstrate the effects of rarefaction on the shock and the shock layer, along with the extent of the slip and temperature jump at the surface. Also, the sensitivity of the flow structure to the gas-surface interaction model, thermal accommodation, and surface catalysis are studied. C1 NASA, Langley Res Ctr, Hampton, VA 23665 USA. Univ Sydney, Sydney, NSW 2006, Australia. RP Moss, JN (reprint author), NASA, Langley Res Ctr, Hampton, VA 23665 USA. NR 20 TC 1 Z9 1 U1 0 U2 3 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2003 VL 40 IS 5 BP 830 EP 843 DI 10.2514/2.6909 PG 14 WC Engineering, Aerospace SC Engineering GA 730XA UT WOS:000185854400027 ER PT J AU Smith, DD Chang, HR Fuller, KA AF Smith, DD Chang, HR Fuller, KA TI Whispering-gallery mode splitting in coupled microresonators SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID OPTICAL WAVE-GUIDE; THRESHOLD CONDITIONS; RING-RESONATOR; PROPAGATION; RESONANCES; BISPHERES AB Using iterative methods we demonstrate that, for a structure consisting of N-coupled microspheres or ring resonators, the morphology-dependent resonances split into N higher-Q modes, in direct analogy with other types of oscillators. Moreover, for odd numbers of identical lossless coupled rings, the circulating intensity in the innermost ring increases exponentially with N when there is strong coupling to even-numbered rings and weak coupling to odd-numbered rings. (C) 2003 Optical Society of America. C1 NASA, George C Marshall Space Flight Ctr, Sci Directorate, Huntsville, AL 35812 USA. Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. RP Smith, DD (reprint author), NASA, George C Marshall Space Flight Ctr, Sci Directorate, Huntsville, AL 35812 USA. NR 16 TC 56 Z9 58 U1 4 U2 19 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD SEP PY 2003 VL 20 IS 9 BP 1967 EP 1974 DI 10.1364/JOSAB.20.001967 PG 8 WC Optics SC Optics GA 719AX UT WOS:000185182000022 ER PT J AU Smith, JG Connell, JW Hergenrother, PM Ford, LA Criss, JM AF Smith, JG Connell, JW Hergenrother, PM Ford, LA Criss, JM TI Transfer molding imide resins based on 2,3,3 ',4 '-biphenyltetracarboxylic dianhydride SO MACROMOLECULAR SYMPOSIA LA English DT Article; Proceedings Paper CT 4th International Symposium on Polycondensates CY SEP 15-18, 2002 CL HAMBURG, GERMANY DE a-BPDA; high temperature polymers; PETI-330; polyimides; resin transfer molding ID TERMINAL PHENYLETHYNYL GROUPS; COMPOSITE PROPERTIES; POLYIMIDE OLIGOMERS; ADHESIVE PROPERTIES; TEMPERATURE; PENDENT; ANHYDRIDES; BLENDS; DESIGN; ACID AB Phenylethynyl containing imide oligomers have been under investigation as part of an effort to develop resins for non-autoclave composite fabrication processes such as resin transfer molding (RTM). These high performance/high temperature composites are potentially useful on advanced aerospace vehicles such as reusable launch vehicles (RLVs). New phenylethynyl terminated imide oligomers (PETI) based upon 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA) were prepared and characterized primarily by rheological behavior and cured glass transition temperature (Tg). In comparison to resins from the symmetrical isomer (3,3',4,4'-biphenyltetracarboxylic dianhydride, s-BPDA), a-BPDA afforded corresponding resins with lower melt viscosities and upon curing, higher Tgs. Several resins exhibited an attractive combination of proper-ties such as low and stable melt viscosities required for RTM composite fabrication, high cured Tgs, and moderate toughness. One resin (P10) was used to fabricate flat, void free laminates by RTM. The laminates exhibited high mechanical properties at temperatures to 288degreesC. The chemistry and physical properties of these new PETIs and the laminate properties of one composition are discussed. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. NASA, Natl Res Council Res Assoc, Hampton, VA 23681 USA. M&P Technol Inc, Marietta, GA 30677 USA. RP Smith, JG (reprint author), NASA, Langley Res Ctr, Hampton, VA 23681 USA. NR 55 TC 26 Z9 31 U1 1 U2 15 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 1022-1360 J9 MACROMOL SYMP JI Macromol. Symp. PD SEP PY 2003 VL 199 BP 401 EP 418 DI 10.1002/masy.200350934 PG 18 WC Polymer Science SC Polymer Science GA 739MJ UT WOS:000186350400035 ER PT J AU Fertl, D Jefferson, TA Moreno, IB Zerbini, AN Mullin, KD AF Fertl, D Jefferson, TA Moreno, IB Zerbini, AN Mullin, KD TI Distribution of the Clymene dolphin Stenella clymene SO MAMMAL REVIEW LA English DT Review DE Atlantic Ocean; cetacean; habitat preference; marine mammal; sighting; stranding ID GULF-OF-MEXICO; ATLANTIC; CETACEA AB 1. The Clymene dolphin Stenella clymene is found in tropical and warm temperate waters of both the North and South Atlantic Oceans. Confusion surrounding the identifying characteristics of this species has contributed to a general lack of knowledge of this species. 2. We collected and verified a total of 195 records ( 109 sightings, 67 strandings, and 19 captures) of Clymene dolphins. Twenty-five per cent (n = 49) of these records were previously unpublished. Rejected records are discussed in order to clarify the literature. 3. The northernmost locations for the Clymene dolphin are 39degrees17 'N, 74degrees35 'W ( NJ, USA) and 19degrees 1.9'N, 16degrees13.5'W (113 km north of Nouakchott, Mauritania). The southernmost locations are 29degrees 58'S, 50degrees07'W (Tramandai, Rio Grande do Sul, Brazil) and 3degrees 40'S, 18degrees5'W ( off Ascension Island). 4. Clymene dolphins were found in waters with bottom depths ranging from 44 to 4500 m ( mean = 1870 m; SE = 110 m; median = 1675 m; n = 94). A single sighting reported at a location with a bottom depth of 44 m is considered to be atypical, as this species has an otherwise exclusively oceanic distribution. 5. Group sizes ranged from at least one individual in a mixed-species school of spinner dolphins Stenella longirostris to a group of an estimated 1000 animals (mean = 76.1; SE = 11; median = 47; n = 105). Stranding group size ranged from 1 to 46 individuals ( n = 67), with single individuals being most common ( n = 60). There is information available for seven mass strandings, all of which occurred in the south-eastern USA. C1 GeoMarine Inc, Plano, TX 75074 USA. Natl Marine Fisheries Serv, SW Fisheries Sci Ctr, La Jolla, CA 92038 USA. GEMARS CECLIMAR, BR-90440150 Porto Alegre, RS, Brazil. Univ Washington, Sch Aquat & Fishery Sci, Seattle, WA 98195 USA. SE Fisheries Sci Ctr, Natl Marine Fisheries Serv, Pascagoula, MS 39567 USA. RP Fertl, D (reprint author), GeoMarine Inc, 550 E 15th St, Plano, TX 75074 USA. RI Moreno, Ignacio/I-3235-2012; Zerbini, Alexandre/G-4138-2012 OI Moreno, Ignacio/0000-0001-9854-6033; NR 72 TC 16 Z9 17 U1 0 U2 4 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0305-1838 J9 MAMMAL REV JI Mammal Rev. PD SEP-DEC PY 2003 VL 33 IS 3-4 BP 253 EP 271 DI 10.1046/j.1365-2907.2003.00033.x PG 19 WC Zoology SC Zoology GA 726JP UT WOS:000185596200004 ER PT J AU O' Keefe, S AF O' Keefe, S TI Facing the challenges of an Integrated Ocean Observing System SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Editorial Material C1 NASA, Washington, DC 20546 USA. RP O' Keefe, S (reprint author), NASA, Washington, DC 20546 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU MARINE TECHNOLOGY SOC INC PI COLUMBIA PA 5565 STERRETT PLACE, STE 108, COLUMBIA, MD 21044 USA SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD FAL PY 2003 VL 37 IS 3 BP 12 EP 14 PG 3 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 755KV UT WOS:000187402800003 ER PT J AU Hankin, S Bernard, L Cornillon, P Grassle, F Legler, D Lever, J Worley, S AF Hankin, S Bernard, L Cornillon, P Grassle, F Legler, D Lever, J Worley, S TI Designing the data and communications infrastructure for the US Integrated Ocean Observing System SO MARINE TECHNOLOGY SOCIETY JOURNAL LA English DT Article AB Central to the vision of the U.S. Integrated Ocean Observing System (IOOS) is a data management infrastructure that joins Federal, regional, state, municipal, academic, and commercial partners in a seamless data-sharing framework. The Data Management and Communications (DMAQ Subsystem of IOOS must be capable of integrating the full spectrum of marine data types and products. The design of the DMAC Subsystem is made particularly challenging by three competing factors: 1) Me data types to be integrated are heterogeneous and have complex structure; 2) Me holdings are physically distributed, with some individual partners contributing petabytes; and 3) IOOS is a loose federation of many organizations, large and small, without a corporate management hierarchy. Designing the DMAC Subsystem goes beyond solving problems of software engineering; the most demanding aspects of the solution lie in community behavior. A plan for the subsystem is described. C1 NOAA, Pacific Marine Environm Lab, Washington, DC USA. NOAA, Natl Data Buoy Ctr, Washington, DC USA. Univ Rhode Isl, Grad Sch Oceanog, Kingston, RI 02881 USA. Rutgers State Univ, Inst Marine & Coastal Sci, Piscataway, NJ 08855 USA. USN, Naval Oceanog Off, Stennis Space Ctr, Washington, DC USA. RP Hankin, S (reprint author), NOAA, Pacific Marine Environm Lab, Washington, DC USA. NR 1 TC 1 Z9 1 U1 0 U2 1 PU MARINE TECHNOLOGY SOC INC PI COLUMBIA PA 5565 STERRETT PLACE, STE 108, COLUMBIA, MD 21044 USA SN 0025-3324 J9 MAR TECHNOL SOC J JI Mar. Technol. Soc. J. PD FAL PY 2003 VL 37 IS 3 BP 51 EP 54 PG 4 WC Engineering, Ocean; Oceanography SC Engineering; Oceanography GA 755KV UT WOS:000187402800011 ER PT J AU Cosgriff, LM Baaklini, GY AF Cosgriff, LM Baaklini, GY TI Ultrasonic spectroscopy of composite rings for space station flywheel rotors SO MATERIALS EVALUATION LA English DT Article DE ultrasonic spectroscopy; resonance; polymer matrix composite material; flywheel rotors; nondestructive testing AB Flywheel energy storage devices consisting of multiple layered composite materials are being studied extensively for utilization in the International Space Station. These composite material systems were investigated with a recently developed ultrasonic spectroscopy technique. The system employs a swept frequency approach and performs a fast Fourier transform on the frequency spectrum of the response signal. In addition, the system allows for equalization of the frequency spectrum, providing all frequencies with equal amounts of energy to excite higher order resonant harmonics. Interpretation of the second fast Fourier transform, along with equalization of the frequency spectrum, offers greater assurance in acquiring and analyzing the fundamental frequency or spectrum resonance spacing. The system can sweep a range of frequencies from an audible range up to 8 MHz, depending on the material and geometry of the component. Single and multiple layered material samples, with and without known discontinuities, were tested to determine how the constituents of a composite material ring system affect the resonant frequency. C1 Cleveland State Univ, NASA, Glenn Res Ctr, Cleveland, OH 44115 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Cosgriff, LM (reprint author), Cleveland State Univ, NASA, Glenn Res Ctr, 21000 Brookpk Rd,MS 6-1, Cleveland, OH 44115 USA. NR 7 TC 0 Z9 0 U1 0 U2 2 PU AMER SOC NON-DESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD SEP PY 2003 VL 61 IS 9 BP 1013 EP 1019 PG 7 WC Materials Science, Characterization & Testing SC Materials Science GA 720CL UT WOS:000185243900005 ER PT J AU Kojima, J Ikeda, Y Nakajima, T AF Kojima, J Ikeda, Y Nakajima, T TI Multi-point time-series observation of optical emissions for flame-front motion analysis SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE combustion; turbulent premixed flames; OH chemiluminescence; flame-front motion; flame velocity; Cassegrain optics; PIV ID PREMIXED TURBULENT COMBUSTION; LASER-INDUCED FLUORESCENCE; LAMINAR; OH; CHEMILUMINESCENCE; VELOCITIES; SYSTEM; ABEL AB A simple optical diagnostic technique to analyse flame-front movement is proposed. Time-series, multi-point optical emission measurements using an aberration-free Cassegrain probe coupled with multiple fibres were performed successfully in turbulent premixed flames. The spatial resolution of the Cassegrain optics was examined using a CCD camera in free space and also in turbulent flame conditions. Spatial intensity distributions of OH*, CH* and C-2* chemiluminescence measured in a two-dimensional laminar flame were Compared with the numerical calculation of one-dimensional profiles of these species, demonstrating the ability of the present optical technique to detect a flame front. The probability density of the instantaneous speed and orientation angle of flame-front displacement were determined locally through a geometric motion analysis of simultaneous, time-evolutional OH* signals at three points. Flow fields measured by PIV were compared with the flame-front velocities to examine differences between gas flow and flame-front dynamics. Errors due to flame curvature, thermal density change and inclined propagation were also estimated. C1 Kobe Univ, Dept Engn Mech, Kobe, Hyogo 6578501, Japan. RP NASA Glenn Res Ctr, Combust Branch 5830, MS OAI,22800 Cedar Point Rd, Cleveland, OH 44142 USA. EM Jun.Kojima@grc.nasa.gov NR 42 TC 14 Z9 14 U1 1 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD SEP PY 2003 VL 14 IS 9 BP 1714 EP 1724 AR PII S0957-0233(03)61877-1 DI 10.1088/0957-0233/14/9/324 PG 11 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 728DF UT WOS:000185699400025 ER PT J AU Keller, JW AF Keller, JW TI Optimization code for an electrostatic mirror charged-particle optical system SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE charged-particle analysers; computer optimization; geophysics; space plasmas ID ENERGY ANALYZER; DESIGN AB Electrostatic mirrors can be formed by two closely spaced metallic grids with an electric potential between them. By shaping the grids, charged-particle optical systems analogous to light optics mirror systems can be developed and conventional optical software tools can be employed to determine the optimal shape and location of the mirrors. However, ray tracing calculations of charged-particle systems that use electrostatic mirrors must account for the penetration of the particles between the grids that make up the mirror. Conventional optimization programs for light optic mirrors do not account for this aberration. We report on a computer code that optimizes the shape and location of electrostatic mirrors. The code uses a first-order solution for the reflection of a charged particle from an electrostatic mirror to rapidly evaluate the path of the rays through the system. C1 Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20715 USA. RP Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20715 USA. EM john.w.keller@nasa.gov RI Keller, John/I-5097-2013 NR 11 TC 1 Z9 1 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-0233 EI 1361-6501 J9 MEAS SCI TECHNOL JI Meas. Sci. Technol. PD SEP PY 2003 VL 14 IS 9 BP N64 EP N68 AR PII S0957-0233(03)61875-8 DI 10.1088/0957-0233/14/9/403 PG 5 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 728DF UT WOS:000185699400030 ER PT J AU Erbe, EF Rango, A Foster, J Josberger, EG Pooley, C Wergin, WP AF Erbe, EF Rango, A Foster, J Josberger, EG Pooley, C Wergin, WP TI Collecting, shipping, storing, and imaging snow crystals and ice grains with low-temperature scanning electron mircoscopy SO MICROSCOPY RESEARCH AND TECHNIQUE LA English DT Article DE snow crystal; ice grain; glacier ice; low-temperature scanning electron microscopy; SEM ID MICROSCOPY; BOUNDARIES; GRAUPEL; FIELD; RIME AB Methods to collect, transport, and store samples of snow and ice have been developed that enable detailed observations of these samples with a technique known as low-temperature scanning electron microscopy (LTSEM). This technique increases the resolution and ease with which samples of snow and ice can be observed, studied, and photographed. Samples are easily collected in the field and have been shipped to the electron microscopy laboratory by common air carrier from distances as far as 5,000 miles. Delicate specimens of snow crystals and ice grains survive the shipment procedures and have been stored for as long as 3 years without undergoing any structural changes. The samples are not subjected to the melting or sublimation artifacts. LTSEM allows individual crystals to be observed for several hours with no detectable changes. Furthermore, the instrument permits recording of photographs containing the parallax information necessary for three-dimensional imaging of the true shapes of snowflakes, snow crystals, snow clusters, ice grains, and interspersed air spaces. This study presents detailed descriptions of the procedures that have been used successfully in the field and the laboratory to collect, ship, store, and image snow crystals and ice grains. Published 2003 Wiley-Liss. Inc. C1 USDA ARS, Beltsville Agr Res Ctr, Soybean Genom & Improvement Lab, Electron Microscopy Unit, Beltsville, MD 20705 USA. New Mexico State Univ, USDA ARS, Jornada Expt Range, Las Cruces, NM 88003 USA. NASA, Goddard Space Flight Ctr, Lab Hydrol Sci, Greenbelt, MD 20771 USA. US Geol Survey, Tacoma, WA 98416 USA. RP Wergin, WP (reprint author), USDA ARS, Beltsville Agr Res Ctr, Soybean Genom & Improvement Lab, Electron Microscopy Unit, Bldg 177B, Beltsville, MD 20705 USA. NR 52 TC 27 Z9 28 U1 1 U2 7 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 1059-910X J9 MICROSC RES TECHNIQ JI Microsc. Res. Tech. PD SEP 1 PY 2003 VL 62 IS 1 BP 19 EP 32 DI 10.1002/jemt.10383 PG 14 WC Anatomy & Morphology; Biology; Microscopy SC Anatomy & Morphology; Life Sciences & Biomedicine - Other Topics; Microscopy GA 713YV UT WOS:000184886300003 PM 12938115 ER PT J AU Malek, CK Hartley, FT Neogi, J AF Malek, CK Hartley, FT Neogi, J TI Fast prototyping of high-aspect ratio, high-resolution X-ray masks by gas-assisted focused ion beam SO MICROSYSTEM TECHNOLOGIES-MICRO-AND NANOSYSTEMS-INFORMATION STORAGE AND PROCESSING SYSTEMS LA English DT Article; Proceedings Paper CT 4th International Workshop on High Aspect Ratio Micro Structure Technology (HARMST 01) CY JUN 17-19, 2001 CL BADEN BADEN, GERMANY ID INDUCED DEPOSITION; FABRICATION; LITHOGRAPHY; TECHNOLOGY AB The capacity of chemically-assisted focused ion beam (FIB) etching systems to undertake direct and highly anisotropic erosion of thin and thick gold (or other high atomic number {Z}) coatings on X-ray mask membranes/substrates provides new levels of precision, flexibility, simplification and rapidity in the manufacture of mask absorber patterns, allowing for fast prototyping of high-aspect ratio, high-resolution masks for deep X-ray lithography for the LIGA process. In preliminary demonstrations, an automated FIB system operating at 30 keV with a gallium liquid metal source and an iodine gas injection system was used for direct milling into a few micrometer thick gold of microstructures into the sub-hundred nanometer regime. Three-dimensional micromachining in bulk diamond is also reported to illustrate the capability of the technique. C1 CNRS, Lab Spect Atom & Ion, UMR8624, F-75700 Paris, France. Univ Paris 11, Lab Utilisat Rayonnement Electromagnet, F-91405 Orsay, France. Louisiana State Univ, Ctr Adv Microstruct & Devices, Baton Rouge, LA 70806 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Norsam Technol, Hillsboro, OR 97124 USA. RP Malek, CK (reprint author), CNRS, Lab Spect Atom & Ion, UMR8624, Bat 350, F-75700 Paris, France. NR 22 TC 8 Z9 8 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0946-7076 J9 MICROSYST TECHNOL JI Microsyst. Technol. PD SEP PY 2003 VL 9 IS 6-7 BP 409 EP 412 DI 10.1007/s00542-002-0215-5 PG 4 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Science & Technology - Other Topics; Materials Science; Physics GA 734DB UT WOS:000186039000006 ER PT J AU Davis, CJ Smith, MD Stern, L Kerr, TH Chiar, JE AF Davis, CJ Smith, MD Stern, L Kerr, TH Chiar, JE TI Near-infrared spectroscopy of (proto)-planetary nebulae: molecular hydrogen excitation as an evolutionary tracer SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE circumstellar matter; ISM : jets and outflows; ISM : kinematics and dynamics; ISM : lines and bands; infrared : stars ID HUBBLE-SPACE-TELESCOPE; PLANETARY-NEBULAE; PROTOPLANETARY NEBULAE; LINE EMISSION; PHOTODISSOCIATION REGIONS; BIPOLAR NEBULAE; IRAS 18062+2410; EGG NEBULA; BOW SHOCKS; HB 5 AB We present an in-depth analysis of molecular excitation in 11 H-2-bright planetary and protoplanetary nebulae (PN and PPN). From newly acquired K-band observations, we extract a number of spectra at positions across each source. H-2 line intensities are plotted on 'column density ratio' diagrams so that we may examine the excitation in and across each region. To achieve this, we combine the shock models of Smith, Khanzadyan & Davis with the photodissociation region (PDR) models of Black & van Dishoeck to yield a shock-plus-fluorescence fit to each data set. Although the combined shock + fluorescence model is needed to explain the low- and high-energy H-2 lines in most of the sources observed (fluorescence accounts for much of the emission from the higher-energy H-2 lines), the relative importance of shocks over fluorescence does seem to change with evolutionary status. We find that shock excitation may well be the dominant excitation mechanism in the least evolved PPN (CRL 2688 - in both the bipolar lobes and in the equatorial plane) and in the most evolved PN considered (NGC 7048). Fluorescence, on the other hand, becomes more important at intermediate evolutionary stages (i.e. in 'young' PN), particularly in the inner core regions and along the inner edges of the expanding post-asymptotic giant branch (AGB) envelope. Since H-2 line emission seems to be produced in almost all stages of post-AGB evolution, H-2 excitation may prove to be a useful probe of the evolutionary status of PPN and PN alike. Moreover, shocks may play an important role in the molecular gas excitation in (P) PN, in addition to the low- and/or high-density fluorescence usually attributed to the excitation in these sources. C1 Joint Astron Ctr, Hilo, HI 96720 USA. Armagh Observ, Armagh BT61 9DG, North Ireland. Univ Victoria, Dept Phys, Victoria, BC V8W 3P6, Canada. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. SETI Inst, Mountain View, CA 94043 USA. RP Davis, CJ (reprint author), Joint Astron Ctr, 660 N Ohoku Pl,Univ Pk, Hilo, HI 96720 USA. NR 83 TC 36 Z9 36 U1 0 U2 2 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP PY 2003 VL 344 IS 1 BP 262 EP 282 DI 10.1046/j.1365-8711.2003.06820.x PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 717KZ UT WOS:000185088800031 ER PT J AU Zhu, YQ Todling, R Guo, J Cohn, SE Navon, IM Yang, Y AF Zhu, YQ Todling, R Guo, J Cohn, SE Navon, IM Yang, Y TI The GEOS-3 retrospective data assimilation system: The 6-hour lag case SO MONTHLY WEATHER REVIEW LA English DT Article ID VARIATIONAL DATA ASSIMILATION; KALMAN SMOOTHER; DIGITAL-FILTER; WEAK CONSTRAINT; IMPLEMENTATION; MODEL; INITIALIZATION; FORMULATION; ALGORITHMS; DYNAMICS AB The fixed-lag Kalman smoother (FLKS) has been proposed as a framework to construct data assimilation procedures capable of producing high-quality climate research datasets. FLKS-based systems, referred to as retrospective data assimilation systems, are an extension to three-dimensional filtering procedures with the added capability of incorporating observations not only in the past and present time of the estimate, but also at future times. A variety of simplifications are necessary to render retrospective assimilation procedures practical. In this article, an FLKS-based retrospective data assimilation system implementation for the Goddard Earth Observing System Data Assimilation System is presented. The practicality of this implementation comes from the practicality of its underlying ( filter) analysis system, that is, the physical-space statistical analysis system (PSAS). The behavior of two schemes is studied here. The first retrospective analysis ( RA) scheme is designed simply to update the regular PSAS analyses with observations available at times ahead of the regular analysis times. Results are presented for when observations 6-h ahead of the analysis time are used to update the PSAS analyses and thereby to calculate the so-called lag-1 retrospective analyses. Consistency tests for this RA scheme show that the lag-1 retrospective analyses indeed have better 6-h predictive skill than the predictions from the regular analyses. This motivates the introduction of the second retrospective analysis scheme, which, at each analysis time, uses the 6-h retrospective analysis to create a new forecast to replace the forecast normally used in the PSAS analysis, and therefore allows the calculation of a revised ( filter) PSAS analysis. This procedure is referred to as the retrospective-based iterated analysis (RIA) scheme. Results from the RIA scheme indicate its potential for improving the overall quality of the assimilation. C1 NASA, Data Assimilat Off, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Zhu, YQ (reprint author), NASA, Data Assimilat Off, Goddard Space Flight Ctr, Code 910-3, Greenbelt, MD 20771 USA. RI Navon, Ionel/A-5173-2008; Cohn, Stephen/K-1954-2012 OI Navon, Ionel/0000-0001-7830-7094; Cohn, Stephen/0000-0001-8506-9354 NR 47 TC 11 Z9 11 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD SEP PY 2003 VL 131 IS 9 BP 2129 EP 2150 DI 10.1175/1520-0493(2003)131<2129:TGRDAS>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 715BY UT WOS:000184951700011 ER PT J AU Park, S Srivastava, D Cho, K AF Park, S Srivastava, D Cho, K TI Generalized chemical reactivity of curved surfaces: Carbon nanotubes SO NANO LETTERS LA English DT Article ID TOTAL-ENERGY CALCULATIONS; SIDEWALL FUNCTIONALIZATION; CHEMISTRY; STRAIN AB We have developed a model to predict the chemical reactivity of carbon nanotubes (CNTs) quantitatively from their initial structures. The parameters, universal for each reaction, of the model can be obtained from a graphene sheet analysis. The chemical reactivity of hydrogenation, hydroxylation, and fluorination were predicted within 0.1-0.3 eV errors, compared with first principle simulation results. The model also predicted the enhanced chemical reactivity of mechanically bent CNTs. The predictions can be applied to the controlled functionalization of CNTs. C1 Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. NASA, Ames Res Ctr, CSC, NAS, Moffett Field, CA 94035 USA. RP Cho, K (reprint author), Stanford Univ, Dept Mech Engn, Stanford, CA 94305 USA. EM kjcho@stanford.edu NR 21 TC 114 Z9 115 U1 1 U2 43 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 SEP PY 2003 VL 3 IS 9 BP 1273 EP 1277 DI 10.1021/nl0342747 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 721RQ UT WOS:000185330700020 ER PT J AU Bozzolo, G Garces, JE Noebe, RD Farias, D AF Bozzolo, G Garces, JE Noebe, RD Farias, D TI Atomistic modelling of nanostructures via the Bozzolo-Ferrante-Smith quantum approximate method SO NANOTECHNOLOGY LA English DT Article ID SURFACE SEGREGATION; TERNARY ALLOYS; CU(111); SYSTEMS; GROWTH; BFS; CO; CU; TI AB Ideally, computational modelling techniques for nanoscopic physics would be able to perform free of limitations on the type and number of elements, while providing comparable accuracy when dealing with bulk or surface problems. Computational efficiency is also desirable, if not mandatory, for properly dealing with the complexity of typical nanostructured systems. A quantum approximate technique, the Bozzolo-Ferrante-Smith method for alloys, which attempts to meet these demands, is introduced for calculation of the energetics of nanostructures. The versatility of the technique is demonstrated through analysis of diverse systems, including multiphase precipitation in a five-element Ni-Al-Ti-Cr-Cu alloy and the formation of mixed composition Co-Cu islands on a metallic Cu(111) substrate. C1 OAI, Cleveland, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Ctr Atom Bariloche, RA-8400 San Carlos De Bariloche, Rio Negro, Argentina. Univ Autonoma Madrid, Dept Fis Mat Condensada, E-28049 Madrid, Spain. RP Bozzolo, G (reprint author), OAI, 22800 Cedar Point Rd, Cleveland, OH 44142 USA. EM Guillermo.H.Bozzolo@grc.nasa.gov RI Farias, Daniel/L-2435-2013 OI Farias, Daniel/0000-0002-8537-8074 NR 20 TC 9 Z9 9 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 EI 1361-6528 J9 NANOTECHNOLOGY JI Nanotechnology PD SEP PY 2003 VL 14 IS 9 BP 939 EP 945 AR PII S0957-4484(03)58772-4 DI 10.1088/0957-4484/14/9/301 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 730QN UT WOS:000185841600003 ER PT J AU Park, C Crooks, RE Siochi, EJ Harrison, JS Evans, N Kenik, E AF Park, C Crooks, RE Siochi, EJ Harrison, JS Evans, N Kenik, E TI Adhesion study of polyimide to single-wall carbon nanotube bundles by energy-filtered transmission electron microscopy SO NANOTECHNOLOGY LA English DT Article AB High-re solution electron microscopy and energy-filtered imaging methods were used to examine single-wall carbon nanotubes and nanotube reinforced polyimide composites. The nanotubes were studied alone, in a polyimide matrix composite, and after deposition of composite material previously dissolved in a solvent. Energy-filtered images based on nitrogen core loss excitations were used to discern the presence of polyimide. Elemental maps of nanotubes extracted from the composite revealed good wetting of the nanotube surfaces by the polyimide. C1 Natl Inst Aerosp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Park, C (reprint author), Natl Inst Aerosp, 144 Res Dr, Hampton, VA 23666 USA. RI Evans, Neal/F-5955-2011 NR 11 TC 31 Z9 31 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD SEP PY 2003 VL 14 IS 9 BP L11 EP L14 DI 10.1088/0957-4484/14/9/101 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 730QN UT WOS:000185841600002 ER PT J AU Kimes, D Nelson, R Levine, E Timmins, S Weiss, S Bollinger, ME Blaisdell, C AF Kimes, D Nelson, R Levine, E Timmins, S Weiss, S Bollinger, ME Blaisdell, C TI Predicting paediatric asthma hospital admissions and ED visits SO NEURAL COMPUTING & APPLICATIONS LA English DT Article DE asthma; Baltimore Maryland; pediatric hospital ID AIR-POLLUTION; CHILDREN AB Historical data for hospital admissions and Emergency Department (ED) visits in Baltimore City contain information concerning temporal patterns of paediatric asthma service utilisation (e.g. number of peaks and troughs, timing, relative magnitudes, steepness of rise and fall of the endemic cycles, etc.). This historical information can be captured by linear and neural network models to accurately predict the level of asthma admissions for the next few days or one week. Using 14 years of data, the best neural network models explained over 80% of the variations in admissions data with root mean square errors of 5-7 admissions per week. Models developed to predict asthma admissions can aid in identifying future peak periods of asthma admissions, alerting and educating individual asthmatic patients to periods of increased risk, and mitigating asthma events that lead to ED and/or hospital admissions. It is believed that these modelling techniques using historical data can be applied to any city or region with similar accuracies. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Decis Syst Technol, Greenbelt, MD USA. Univ Maryland, Sch Pharm, Ctr Drugs & Publ Policy, Baltimore, MD 21201 USA. Univ Maryland, Sch Med, Dept Epidemiol & Prevent Med, Baltimore, MD 21201 USA. Univ Maryland, Sch Med, Div Pediat Pulmonol & Allergy, Baltimore, MD 21201 USA. RP Kimes, D (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NR 21 TC 1 Z9 1 U1 0 U2 2 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0941-0643 J9 NEURAL COMPUT APPL JI Neural Comput. Appl. PD SEP PY 2003 VL 12 IS 1 BP 10 EP 17 DI 10.1007/s00521-003-0366-z PG 8 WC Computer Science, Artificial Intelligence SC Computer Science GA 734DH UT WOS:000186039600002 ER PT J AU Lulla, K AF Lulla, K TI Nighttime urban imagery from international space station: Potential applications for urban analyses and modeling SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77059 USA. RP Lulla, K (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77059 USA. NR 3 TC 2 Z9 2 U1 0 U2 0 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 SEP PY 2003 VL 69 IS 9 BP 941 EP 942 PG 2 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 817RG UT WOS:000221194000002 ER PT J AU Lo, CP Quattrochi, DA AF Lo, CP Quattrochi, DA TI Land-use and land-cover change, urban heat island phenomenon, and health implications: A remote sensing approach SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID SURFACE-TEMPERATURE; VEGETATION INDEX; ATLANTA; ASTHMA; OZONE; IMAGES AB Land-use and land-cover maps of Atlanta Metropolitan Area in Georgia were produced from Landsat MSS and TM images for 1973, 1979, 1983, 1987, 1992, and 1997, spanning a period of 25 years. Dramatic changes in land use and land cover have occurred, with loss of forest and cropland to urban use. In particular, low-density urban use, which includes largely residential use, has increased by over 119 percent between 1973 and 1997. These land-use and land-cover changes have drastically altered the land surface characteristics. An analysis of Landsot images revealed an increase in surface temperature and a decline in NDVI from 1973 to 1997. These changes have forced the development of a significant urban heat island effect at both the urban canopy and urban boundary layers as well as an increase in ground level ozone production to such an extent that Atlanta has violated EPA's ozone level standard in recent years. Using canonical correlation analysis, surface temperatures and NDVI, extracted from Landsat TM images, were found to correlate strongly with volatile organic compounds (VOC) and nitrogen oxides (NOx) emissions, the two ingredients that form ozone by reacting with sunlight, but only weakly with the rates of cardiovascular and chronic lower respiratory diseases, which also did not exhibit strong correlation with VOC and NOx emissions, possibly because other factors such as demographic and socio-economic may also be involved. Further research is therefore needed to understand the health geography and its relationship to land-use and land-cover change. This paper illustrates the usefulness of a remote sensing approach for this purpose. C1 Univ Georgia, Dept Geog, Athens, GA 30602 USA. NASA, Marshall Space Flight Ctr, Dept Earth Sci, Huntsville, AL 35812 USA. RP Lo, CP (reprint author), Univ Georgia, Dept Geog, Athens, GA 30602 USA. EM chpanglo@uga.edu; dale.quattrochi@nasa.gov NR 37 TC 89 Z9 96 U1 4 U2 42 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 SEP PY 2003 VL 69 IS 9 BP 1053 EP 1063 PG 11 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA 817RG UT WOS:000221194000014 ER PT J AU Oyafuso, F Klimeck, G von Allmen, P Boykin, T Bowen, RC AF Oyafuso, F Klimeck, G von Allmen, P Boykin, T Bowen, RC TI Strain effects in large-scale atomistic quantum dot simulations SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 4th Motorola Workshop on Computational Materials and Electronics CY NOV 14-15, 2002 CL TEMPE, ARIZONA ID ENERGY AB Atomistic computations of electronic properties for nanostructures with strain (such as self-assembled quantum dots) typically consist of two components - a calculation of the individual atomic positions and the eigenstates of interest in the resulting Hamiltonian. Such simulations ultimately require artificial boundary conditions either through a truncation of the simulation domain or by the imposition of periodic boundary conditions, which necessarily introduce inaccuracies in both components of the computation. In simulations that include up to about 20 million atoms, it is demonstrated that the simulation domain truncation has little impact on the direct computation of the electronic energies but causes considerable inaccuracies in the calculation of the atomic positions unless the simulation domain is made much larger than the central quantum dot structure. The long-range nature of the lattice distortions induced by lattice mismatch is consequently expected to significantly alter the electronic structure of nearby quantum dots. (C) 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Alabama, Dept Elect & Comp Engn, Huntsville, AL 35899 USA. RP Oyafuso, F (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 169-315, Pasadena, CA 91109 USA. RI Klimeck, Gerhard/A-1414-2012 OI Klimeck, Gerhard/0000-0001-7128-773X NR 15 TC 12 Z9 12 U1 0 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 SEP PY 2003 VL 239 IS 1 BP 71 EP 79 DI 10.1002/pssb.200303238 PG 9 WC Physics, Condensed Matter SC Physics GA 720YF UT WOS:000185289700009 ER PT J AU Bell, NF Sawyer, RF Volkas, RR Wong, YYY AF Bell, NF Sawyer, RF Volkas, RR Wong, YYY TI State permutations from manipulation of near-level-crossings SO PHYSICAL REVIEW A LA English DT Article ID PARADOX AB We discuss some systematic methods for implementing state manipulations in systems formally similar to chains of a few spins with nearest-neighbor interactions, arranged such that there are strong and weak scales of coupling links. States are permuted by means of bias potentials applied to a few selected sites. This generic structure is then related to an atoms-in-a-cavity model that has been proposed in the literature as a way of achieving a decoherence-free subspace. A method using adiabatically varying laser detuning to implement a controlled NOT gate in this model is proposed. C1 NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Univ Melbourne, Sch Phys, High Energy Phys Res Ctr, Parkville, Vic 3010, Australia. Univ Delaware, Dept Phys & Astron, Newark, DE 19716 USA. RP Bell, NF (reprint author), NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD SEP PY 2003 VL 68 IS 3 AR 032307 DI 10.1103/PhysRevA.68.032307 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 728KQ UT WOS:000185716700025 ER PT J AU Penanen, K Packard, RE AF Penanen, K Packard, RE TI Velocity-dependent effective inertial mass in superfluid He-3 SO PHYSICAL REVIEW B LA English DT Article ID DEPRESSION; TRANSITION; DENSITY AB We show that a solid body moving in superfluid He-3 acquires a velocity-dependent effective mass. The effect is a consequence of the suppression of the superfluid density associated with depairing in a flowing BCS fluid. The counterflow associated with the body's motion is greater than for a simple inviscid fluid. To leading order, the mass increase is quadratic in velocity. We show that this effect leads to nonlinearities in the motion of a simple system such as a solid object subject to a linear restoring force. Our model may explain some of the nonlinear behavior seen in vibrating wire oscillators at very low temperatures. The depairing term will also contribute to the low-velocity counterflow mass increase in excess to what is expected from the ideal fluid model. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Penanen, K (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 11 TC 0 Z9 0 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD SEP 1 PY 2003 VL 68 IS 9 AR 092504 DI 10.1103/PhysRevB.68.092504 PG 4 WC Physics, Condensed Matter SC Physics GA 728LA UT WOS:000185717600022 ER PT J AU Lallemand, P Luo, LS AF Lallemand, P Luo, LS TI Theory of the lattice Boltzmann method: Acoustic and thermal properties in two and three dimensions SO PHYSICAL REVIEW E LA English DT Article ID RAYLEIGH-BENARD CONVECTION; NAVIER-STOKES EQUATIONS; MACH NUMBER COMBUSTION; COMPRESSIBLE FLOWS; BGK MODELS; SCHEME; SIMULATIONS; STABILITY; GAS; DISSIPATION AB The focus of the present work is to provide an analysis for the acoustic and thermal properties of the energy-conserving lattice Boltzmann models, and a solution to the numerical defects and instability associated with these models in two and three dimensions. We discover that a spurious algebraic coupling between the shear and energy modes of the linearized evolution operator is a defect universal to the energy-conserving Boltzmann models in two and three dimensions. This spurious mode coupling is highly anisotropic and may occur at small values of wave number k along certain directions, and it is a direct consequence of the following key features of the lattice Boltzmann equation: (1) its simple spatial-temporal dynamics, (2) the linearity of the relaxation modeling for collision operator, and (3) the energy-conservation constraint. To eliminate the spurious mode coupling, we propose a hybrid thermal lattice Boltzmann equation (HTLBE) in which the mass and momentum conservation equations are solved by using the multiple-relaxation-time model due to d'Humieres, whereas the diffusion-advection equation for the temperature is solved separately by using finite-difference technique (or other means). Through the Chapman-Enskog analysis we show that the hydrodynamic equations derived from the proposed HTLBE model include the equivalent effect of gamma=C-P/C-V in both the speed and attenuation of sound. Appropriate coupling between the energy and velocity field is introduced to attain correct acoustics in the model. The numerical stability of the HTLBE scheme is analyzed by solving the dispersion equation of the linearized collision operator. We find that the numerical stability of the lattice Boltzmann scheme improves drastically once the spurious mode coupling is removed. It is shown that the HTLBE scheme is far superior to the existing thermal LBE schemes in terms of numerical stability, flexibility, and possible generalization for complex fluids. We also present the simulation results of the convective flow in a rectangular cavity with different temperatures on two opposite vertical walls and under the influence of gravity. Our numerical results agree well with the pseudospectral result. C1 Univ Paris 11, Lab ASCI, F-91405 Orsay, France. NASA, ICASE, Langley Res Ctr, Hampton, VA 23681 USA. RP Univ Paris 11, Lab ASCI, Batiment 506, F-91405 Orsay, France. EM lalleman@asci.fr; luo@NIAnet.org RI Luo, Li-Shi/A-4561-2011 OI Luo, Li-Shi/0000-0003-1215-7892 NR 70 TC 221 Z9 228 U1 5 U2 59 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0045 EI 2470-0053 J9 PHYS REV E JI Phys. Rev. E PD SEP PY 2003 VL 68 IS 3 AR 036706 DI 10.1103/PhysRevE.68.036706 PN 2 PG 25 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 729DK UT WOS:000185756400109 PM 14524925 ER PT J AU Grady, CA Proffitt, CR Malumuth, E Woodgate, BE Gull, TR Bowers, CW Heap, SR Kimble, RA Lindler, D Plait, P Weinberger, A AF Grady, CA Proffitt, CR Malumuth, E Woodgate, BE Gull, TR Bowers, CW Heap, SR Kimble, RA Lindler, D Plait, P Weinberger, A TI Coronagraphic imaging with the Hubble Space Telescope and the space telescope imaging spectrograph SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID HERBIG AE STAR; CIRCUMSTELLAR DISK; ENVIRONMENT; HD-100546; AURIGAE AB The unfiltered Space Telescope Imaging Spectrograph (STIS) CCD in tandem with focal plane wedges and a Lyot stop provides a simple white-light coronagraph with a bandpass of 0.2-1.0 mum, which has been used since late 1998 to image nebulosity around stars in the ranges 0.34 less than or equal to V less than or equal to 14 and -0.03 less than or equal to B-V less than or equal to 1.65. The residual starlight seen in STIS coronagraphic images includes diffraction spikes due to the Hubble Space Telescope (HST) secondary support structure, lacks distinct Airy rings, and varies smoothly with radius from the star. The point-spread function (PSF) shape is a strong function of the source spectral energy distribution: we find that the PSF template needs to differ from the occulted source color by Delta(B-V) less than or equal to 0.08 mag. Optimal PSF removal is achieved for contemporary template observations matched to HST orbital phase of the science observations. Use of noncontemporary PSF templates can degrade the limiting contrast by up to a factor of 10-12 at r less than or equal to 2". These systematic effects are negligible when the nebular surface brightness is comparable to the residual starlight, and they become progressively more important as surface brightness decreases. STIS has been used to detect circumstellar envelopes and protoplanetary disks with surface brightnesses spanning 10(-4) to 10(-7) per HST resolution element per F-star at 2" from the star, debris disks with F-IR/F-star greater than or equal to 0.001, and emission-line nebulosity associated with bipolar outflows. The limiting contrast for single- orbit integrations with the star placed at a location where the coronagraphic wedge is 1".0 wide is 10(-8) per HST resolution element per F-star for 6 less than or equal to V less than or equal to 8 stars. Deeper imagery can be obtained by placing the star off the active detector area. When the star is 5" from the detector, a limiting contrast for a single-orbit integration of 2.5 x 10(-10) per HST resolution element per F-star is reached. At this contrast level, background objects and the stellar color variability prevent further improvement by co-adding data from multiple orbits. C1 NASA, Goddard Space Flight Ctr, NOAO STIS, Greenbelt, MD 20771 USA. Eureka Sci, Oakland, CA 94602 USA. Comp Sci Corp, Sci Programs, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. Catholic Univ Amer, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Sigma Res & Engn, Lanham, MD 20706 USA. Sonoma State Univ, Dept Phys & Astron, Rohnert Pk, CA 94928 USA. Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. RP Grady, CA (reprint author), NASA, Goddard Space Flight Ctr, NOAO STIS, Code 681, Greenbelt, MD 20771 USA. RI Gull, Theodore/D-2753-2012; Woodgate, Bruce/D-2970-2012; Kimble, Randy/D-5317-2012; heap, sara/E-2237-2012 OI Gull, Theodore/0000-0002-6851-5380; NR 21 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 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD SEP PY 2003 VL 115 IS 811 BP 1036 EP 1049 DI 10.1086/377083 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 714GA UT WOS:000184902900002 ER PT J AU Vrtilek, SD Raymond, JC Boroson, B McCray, R Smale, A Kallman, T Nagase, F AF Vrtilek, SD Raymond, JC Boroson, B McCray, R Smale, A Kallman, T Nagase, F TI Simultaneous ASCA and Hubble Space Telescope GHRS observations of Cygnus X-2/V1341 Cygni SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF THE PACIFIC LA English DT Article ID X-RAY BINARIES; MULTIWAVELENGTH CAMPAIGN; EMISSION-LINES; X-2; SPECTRUM; IUE; HERCULES-X-1; SPECTROMETER; SCORPIUS-X-1; PERIODICITY AB We present results from ultraviolet and X-ray observations of the low-mass X-ray binary Cygnus X-2. The simultaneous Hubble Space Telescope/GHRS and ASCA observations took place during the low state of an 82 day cycle. We compare our observations as well as archival IUE and RXTE data with models that predict ultraviolet and optical continuum emission from an X-ray-heated disk and a Roche lobe-filling star. The model predictions are consistent with observed optical, ultraviolet, and X-ray variations over both orbital and long-term periods. The X-ray spectral state, the luminosities implied by fits to the X-ray data, the ultraviolet continuum and line fluxes, and the mass accretion rates obtained from fits to the ultraviolet continuum are consistent with location of our observations on the normal and horizontal branches of the Z-shaped X-ray color- color diagram. A combination of changes to mass accretion rate and obstruction by a warped disk can be invoked as a possible explanation for the motion of the "Z" in the color- color plane. The GHRS/G160M measurements concentrated on N v (lambda1238.8; lambda1242.8) and He II (lambda1640.5). The low-resolution (GHRS/G140L) observations captured Si IV (lambda1393.8; lambda1402.8), N IVv (lambda1486.5), and C IV (lambda1548); absorption lines detected in the spectra are interstellar. Although the relative line fluxes are consistent with emission from an X-ray-heated accretion disk corona, predictions from models of line emission from simple disks do not fit the observed emission-line profiles. The lack of double peaks suggests that most of the line emission is from the surface of the companion and the radial velocities (80-130 km s(-1)) are consistent with emission from the optical star at the orbital phase (0.70-0.74) of our observations. C1 Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. MIT, Cambridge, MA 02138 USA. Univ Colorado, JILA, Boulder, CO 80309 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20177 USA. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. RP Vrtilek, SD (reprint author), Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA. NR 44 TC 11 Z9 11 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6280 J9 PUBL ASTRON SOC PAC JI Publ. Astron. Soc. Pac. PD SEP PY 2003 VL 115 IS 811 BP 1124 EP 1134 DI 10.1086/377089 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 714GA UT WOS:000184902900008 ER PT J AU Decker, KLM Boerner, REJ AF Decker, KLM Boerner, REJ TI Elevation and vegetation influences on soil properties in Chilean Nothofagus forests SO REVISTA CHILENA DE HISTORIA NATURAL LA English DT Article DE Chilean Andes; leaf lifespan; nitrogen mineralization; nitrification; Nothofagus; soil carbon ID OLD-GROWTH FOREST; NITROGEN MINERALIZATION; DYNAMICS; PHOSPHORUS; EVERGREEN; PATTERNS; CARBON AB We measured net nitrogen mineralization, not nitrification, proportional nitrification, and total inorganic nitrogen, available phosphorus, and soil organic carbon in five Andean forested stands in an attempt to resolve the relative influence of elevation and forest canopy composition on soil organic matter and nutrient dynamics in this ecosystem type. Our five forested study sites were within a contiguous Nothofagus forest that ranged from 1,280 to 1,700 m elevation in the central Chilean Andes. The five sites consisted of three single species stands, one each of the low elevation deciduous N. obliqua, the evergreen N. dombeyi, or the high elevation deciduous N. pumilio, as well as two mixed evergreen-deciduous stands. There was no statistically significant relationship of nitrogen mineralization or phosphorus with elevation. In contrast, there were statistically significant, though weak, negative relationships between elevation and net nitrification, proportional nitrification, soil pH and organic carbon. In general, soils from the N. obliqua stand had higher levels/rates of nitrification, soil organic carbon content, soil pH, and plant available phosphorus than soils form the other single species stands. In contrast, the N. dombeyi and N. pumilio stands had lower rates of nitrification and soil pH than did the N. obliqua stand. The evergreen-deciduous mixed stands tended to be intermediate in soil properties. These results demonstrate that vegetation, particularly the balance of evergreen and deciduous species, exerts stronger control over soil chemical and biochemical properties than the climate variations induced by 350 m in elevation, even where the evergreen and deciduous species are closely-related angiosperms. C1 Ohio State Univ, Dept Ecol Evolut & Organismal Biol, Columbus, OH 43210 USA. RP Decker, KLM (reprint author), NASA, Ames Res Ctr, Ecosyst Sci & Technol Branch, Mail Stop 242-4, Moffett Field, CA 94035 USA. RI Decker, Kelly/J-1831-2012 NR 24 TC 6 Z9 8 U1 0 U2 6 PU SOCIEDAD BIOLGIA CHILE PI SANTIAGO PA CASILLA 16164, SANTIAGO 9, CHILE SN 0716-078X J9 REV CHIL HIST NAT JI Rev. Chil. Hist. Nat. PD SEP PY 2003 VL 76 IS 3 BP 371 EP 381 PG 11 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA 719DE UT WOS:000185187700003 ER PT J AU Kemp, PS Gilvear, DJ Armstrong, JD AF Kemp, PS Gilvear, DJ Armstrong, JD TI Do juvenile Atlantic salmon parr track local changes in water velocity? SO RIVER RESEARCH AND APPLICATIONS LA English DT Article; Proceedings Paper CT Joint Meeting on Environmental Flows for River Systems/4th International Ecohydraulics Symposium CY MAR, 2002 CL CAPE TOWN, SOUTH AFRICA DE discharge; velocity; flume; optimal foraging; behaviour; Salmo salar; parr; instream flow models ID IDEAL FREE DISTRIBUTION; BROWN TROUT; PERCEPTUAL CONSTRAINTS; ARTIFICIAL STREAM; STEELHEAD TROUT; SALAR L; HABITAT; SELECTION; WILD; FLOW AB When given a choice of two flows and constant food availability, salmon parr should choose the lower flow if they are to optimize their net energy gain. In a two-choice test carried out in a recirculating flume, there was no significant selection for ranges of naturally occurring high (mean mid-column velocities of 19.5-25.2 cm s(-1)) or low (7.2-10.0 cm s(-1)) summer flows. To test whether this result might indicate that only a proportion of the population chose optimal flows, the positions of the flows were reversed. All fish that initially chose low flow remained site-attached when the flows were reversed. A significant proportion of the fish that initially chose high flow moved when the flows were reversed. Hence, there is no evidence that salmon can integrate energy costs and gains to optimize their feeding positions. However, the behaviour of some individual fish was consistent with a,rule of thumb' of following high flows, which may improve foraging efficiency in natural streams above random in the long but not short term. The findings show that only a fraction of the parr in a population redistribute themselves in response to changes in discharge and therefore a fundamental assumption of some instream flow models is questioned. (C) Crown Copyright 2003. Reproduced with the permission of her majesty's stationery office. Published by John Wiley Sons, Ltd. C1 Univ Stirling, Fac Nat Sci, Stirling FK9 4LA, Scotland. RP Kemp, PS (reprint author), NW Fisheries Sci Ctr, Natl Marine Fisheries Serv, 3305 E Commerce St, Pasco, WA 99301 USA. EM paul.kemp@noaa.gov OI Gilvear, David/0000-0003-3859-8290 NR 37 TC 18 Z9 20 U1 3 U2 7 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1535-1459 EI 1535-1467 J9 RIVER RES APPL JI River Res. Appl. PD SEP-DEC PY 2003 VL 19 IS 5-6 BP 569 EP 575 DI 10.1002/rra.727 PG 7 WC Environmental Sciences; Water Resources SC Environmental Sciences & Ecology; Water Resources GA 736MJ UT WOS:000186174300013 ER PT J AU Mitrofanov, IG Litvak, ML Kozyrev, AS Sanin, AB Tret'yakov, VI Boynton, WV Shinohara, C Hamara, D Saunders, S Drake, DM AF Mitrofanov, IG Litvak, ML Kozyrev, AS Sanin, AB Tret'yakov, VI Boynton, WV Shinohara, C Hamara, D Saunders, S Drake, DM TI Search for water in Martian soil using global neutron mapping by the Russian HEND instrument onboard the US 2001 Mars Odyssey spacecraft SO SOLAR SYSTEM RESEARCH LA English DT Article ID THERMAL EMISSION SPECTROMETER; NEAR-SURFACE; GROUND ICE; HYDROGEN; DEPOSITS AB We present the first results of the global neutron mapping of Mars by the Russian High-Energy Neutron Detector (HEND) onboard the US 2001 Mars Odyssey spacecraft. Global neutron maps of Mars in various spectral ranges allow the content of water ice and adsorbed and bound water in a near-surface layer of the planet I to 2 in in thickness to be estimated. Huge regions of permafrost with a high (several tens of percent by weight) content of water ice are shown to be present in the north and the south of Mars. The continuous observations of Mars for 12 months, from February 18, 2002, through February 8, 2003, are indicative of significant seasonal variations on Mars where the transition from northern winter to northern summer occurred. C1 Russian Acad Sci, Inst Space Res, Moscow 117997, Russia. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Jet Prop Lab, Pasadena, CA 91109 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mitrofanov, IG (reprint author), Russian Acad Sci, Inst Space Res, Profsoyuznaya 84-32, Moscow 117997, Russia. NR 26 TC 18 Z9 18 U1 0 U2 4 PU MAIK NAUKA/INTERPERIODICA/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0038-0946 J9 SOLAR SYST RES+ JI Solar Syst. Res. PD SEP-OCT PY 2003 VL 37 IS 5 BP 366 EP 377 DI 10.1023/A:1026018811877 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 735UQ UT WOS:000186133300002 ER PT J AU Litvak, ML Mitrofanov, IG Kozyrev, AS Sanin, AB Tret'yakov, VI Boynton, WV Shinohara, C Hamara, D Saunders, S Drake, DM Zuber, MT Smith, DE AF Litvak, ML Mitrofanov, IG Kozyrev, AS Sanin, AB Tret'yakov, VI Boynton, WV Shinohara, C Hamara, D Saunders, S Drake, DM Zuber, MT Smith, DE TI Seasonal neutron-flux variations in the polar caps of Mars as revealed by the Russian HEND instrument onboard the NASA 2001 Mars Odyssey spacecraft SO SOLAR SYSTEM RESEARCH LA English DT Article ID SURFACE; HYDROGEN AB We analyze the flux of epithermal neutrons from the Martian surface recorded by the Russian Highy Energy Neutron Detector (HEND) from February 19 through December 19, 2002. The HEND was installed onboard the NASA 2001 Mars Odyssey spacecraft and is designed to measure neutron fluxes with energies above I eV. Over the period of observations, statistically significant variations in the flux of epithermal (10-100 keV) neutrons were found in the northern and southern polar caps. The largest neutron-flux variations were found at subpolar latitudes, where the relative difference between the summer and winter values can reach severalfold. This correlation becomes weaker with increasing distance from the poles. Thus, the relative chan-e in the neutron flux near the 60degrees parallel is slightly more than 10%. We assume that the detected variations result from the global circulation of atmospheric carbon dioxide in subpolar Martian regions. To additionally test this assumption, we compared the HEND neutron measurements onboard 2001 Mars Odyssey and the seasonal variations in the CO(2)-layer thickness as observed by the Mars Orbital Laser Altimeter (MOLA) onboard Mars Global Surveyor (MGS). C1 Russian Acad Sci, Inst Space Res, Moscow 117997, Russia. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Jet Prop Lab, Pasadena, CA 91109 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. MIT, Cambridge, MA 02139 USA. RP Litvak, ML (reprint author), Russian Acad Sci, Inst Space Res, Profsoyuznaya 84-32, Moscow 117997, Russia. NR 12 TC 6 Z9 6 U1 0 U2 1 PU MAIK NAUKA/INTERPERIODICA/SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0038-0946 J9 SOLAR SYST RES+ JI Solar Syst. Res. PD SEP-OCT PY 2003 VL 37 IS 5 BP 378 EP 386 DI 10.1023/A:1026070828716 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 735UQ UT WOS:000186133300003 ER PT J AU Basilevsky, AT Litvak, ML Mitrofanov, IG Boynton, WV Saunders, RS Head, JW AF Basilevsky, AT Litvak, ML Mitrofanov, IG Boynton, WV Saunders, RS Head, JW TI Search for traces of chemically bound water in the Martian surface layer based on HEND measurements onboard the 2001 Mars Odyssey spacecraft SO SOLAR SYSTEM RESEARCH LA English DT Article ID THERMAL EMISSION SPECTROMETER; NEAR-SURFACE; GROUND ICE; DEPOSITS; STABILITY; BEHAVIOR; HYDROGEN; INERTIA AB Analysis of the distribution of the epithermal and fast neutron fluxes from the Martian surface within the +/-60degrees latitude zone measured by the High-Energy Neutron Detector (HEND) from mid-February through mid-June 2002 has revealed regional neutron-flux variations outside the zones of climatic effects, which appear to be attributable to the presence of chemically bound water. With the exception of the epithermal neutron fluxes in Arabia and southwest of Olympus Mons (Medusae Fossae), these variations show no correlation with the geologic structure of the terrain at the level of global geologic maps. The lack of such a correlation probably implies that to the formation depth of the epithermal neutron flux (1-2 m), let alone the fast neutron flux (20-30 cm), much of Mars is covered by a surface material that bears little relation in composition to local bedrocks. Clearly, this is an aeolian cover whose fine-grain component was mixed by dust storms in the geologic time on the scale of large re-ions. The decrease in the flux of epithermal neutrons in Arabia and southwest of Olympus Mons (Medusae Fossae) appears to be attributable to an enhanced concentration of materials containing chemically bound water (clay minerals, palagonite, hydroxides, and hydrosalts) in the surface layers of these regions. C1 Russian Acad Sci, Vernadsky Inst Geochem & Analyt Chem, Moscow 119991, Russia. Russian Acad Sci, Inst Space Res, Moscow 117997, Russia. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Jet Prop Lab, Pasadena, CA 91109 USA. Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. RP Basilevsky, AT (reprint author), Russian Acad Sci, Vernadsky Inst Geochem & Analyt Chem, Ul Kosygina 19, Moscow 119991, Russia. NR 37 TC 8 Z9 8 U1 0 U2 1 PU MAIK NAUKA/INTERPERIODICA PI NEW YORK PA C/O KLUWER ACADEMIC-PLENUM PUBLISHERS, 233 SPRING ST, NEW YORK, NY 10013-1578 USA SN 0038-0946 J9 SOLAR SYST RES+ JI Solar Syst. Res. PD SEP-OCT PY 2003 VL 37 IS 5 BP 387 EP 396 DI 10.1023/A:1026022912786 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 735UQ UT WOS:000186133300004 ER PT J AU Vandooren, A Cristoloveanu, S Conley, JF Mojarradi, M Kolawa, E AF Vandooren, A Cristoloveanu, S Conley, JF Mojarradi, M Kolawa, E TI A systematic investigation of the degradation mechanisms in SOI n-channel LD-MOSFETs SO SOLID-STATE ELECTRONICS LA English DT Article DE LD-MOSFET; SOI; irradiation; hot-carrier degradation; low temperature; breakdown voltage; series resistance ID GATE AB The operation and degradation mechanisms in silicon on insulator LD-MOSFETs are governed by the series resistance which is back-gate bias dependent. The influence of the back-gate bias during degradation and subsequent testing is investigated and modeled. The damage formation and overall loss in LD-MOSFETs performance induced by irradiation, hot-carrier injection, or low temperature are complex and remarkably different from the more usual case of low-voltage CMOS transistors. The series resistance can change by a factor of 4 according to the back-gate bias and radiation dose. The degradation processes are clearly identified and the main parameters (oxide charges, traps at the front and back interfaces, series resistances) are extracted using a simple model of the LD-MOSFET, which accounts for the modification of the drift region resistance. (C) 2003 Elsevier Science Ltd. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. ENSERG, IMEP, URA CNRS & INPG, F-38016 Grenoble 1, France. RP Vandooren, A (reprint author), Motorola Inc, Adv Prod Res & Dev Lab, Digital DNA Labs, 3501 Ed Bluestein Blvd,MD-K10, Austin, TX 78721 USA. NR 15 TC 2 Z9 3 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD SEP PY 2003 VL 47 IS 9 BP 1419 EP 1427 DI 10.1016/S0038-1101(03)00101-1 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 698TK UT WOS:000184014700001 ER PT J AU Nigam, S Kim, J Luo, B Ren, F Chung, GY Shenai, K Neudeck, PG Pearton, SJ Williams, JR AF Nigam, S Kim, J Luo, B Ren, F Chung, GY Shenai, K Neudeck, PG Pearton, SJ Williams, JR TI Role of device area, mesa length and metal overlap distance on breakdown voltage of 4H-SiC p-i-n rectifiers SO SOLID-STATE ELECTRONICS LA English DT Article ID DESIGN CONSIDERATIONS; DIODES; SCHOTTKY; TERMINATION; STATE AB The reverse breakdown voltage (V-B) of p-i-n rectifiers fabricated on 4H-SiC was measured as a function of device active area, mesa length and metal overlap distance for diodes with SiO2 passivated mesa edge termination. V-B was inversely dependent on device area for the range 0.01-0.36 mm(2), decreasing from similar to-1030 to similar to-730 V. The breakdown voltage was not dependent on mesa length and was maximized at similar to5 mum metal overlap distance. The on/off ratio was similar to10(4) at 3.5/-1000 V, with the power figure-of-merit V-B(2)/R-ON reaching values as high as 84.5 MW cm(-2). (C) 2003 Elsevier Science Ltd. All rights reserved. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Sterling Semicond, Tampa, FL 33619 USA. Univ Illinois, Dept Elect Engn & Comp Sci, Chicago, IL 60607 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Auburn Univ, Dept Phys, Auburn, AL 36849 USA. RP Ren, F (reprint author), Univ Florida, Dept Chem Engn, POB 116005, Gainesville, FL 32611 USA. RI Kim, Jihyun/F-6940-2013 NR 17 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD SEP PY 2003 VL 47 IS 9 BP 1461 EP 1464 DI 10.1016/S0038-1101(03)00072-8 PG 4 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 698TK UT WOS:000184014700007 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 An atomistic model for the simulation of acoustic phonons, strain distribution, and Gruneisen coefficients in zinc-blende semiconductors SO SUPERLATTICES AND MICROSTRUCTURES LA English DT Article; Proceedings Paper CT 6th International Conference on New Phenomena in Mesoscopic Structures/4th International Conference on Surfaces and Interfaces of Mesoscopic Devices CY DEC 01-05, 2003 CL Maui, HI DE anharmonicity; phonons; strain; Gruneisen coefficient; InAs; GaAs ID DIAMOND-STRUCTURE; CRYSTALS AB An accurate modeling of phonons, strain distributions, and Grimeisen coefficients is essential for the qualitative and quantitative design of modern nanoelectronic and nanooptoelectronic devices. The challenge is the development of a model that fits within an atomistic representation of the overall crystal yet remains computationally tractable. A simple model for introducing the anharmonicity of the interatomic potential into the Keating two-parameter valence-force-field model is developed. The new method is used for the calculation of acoustic phonon and strain effects in zinc-blende semiconductors. The model is fitted to the Gruneisen coefficients for long-wavelength acoustic phonons and reproduces the response to strain throughout the Brillouin zone in reasonable agreement with experiment. (C) 2004 Published by Elsevier Ltd. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Purdue Univ, Sch Elect Engn, Network Computat Nanotechnol, W Lafayette, IN 47906 USA. RP Lazarenkova, OL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 169-315, 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 6 TC 11 Z9 11 U1 0 U2 3 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0749-6036 J9 SUPERLATTICE MICROST JI Superlattices Microstruct. PD SEP-DEC PY 2003 VL 34 IS 3-6 BP 553 EP 556 DI 10.1016/j.spmi.2004.03.057 PG 4 WC Physics, Condensed Matter SC Physics GA 849WG UT WOS:000223571600065 ER PT J AU Wagner, CT Lu, IY Trent, JD Connor, J AF Wagner, CT Lu, IY Trent, JD Connor, J TI Interaction of cytosolic chaperonin with the erythrocyte cytoskeleton during storage SO TRANSFUSION LA English DT Meeting Abstract CT 56th Annual Meeting of the American-Association-of-Blood-Banks CY NOV 01-14, 2003 CL SAN DIEGO, CALIFORNIA SP Amer Assoc Blood Banks C1 LifeCell Corp, Branchberg, NJ USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER ASSOC BLOOD BANKS PI BETHESDA PA 8101 GLENBROOK RD, BETHESDA, MD 20814-2749 USA SN 0041-1132 J9 TRANSFUSION JI Transfusion PD SEP PY 2003 VL 43 IS 9 SU S BP 66A EP 67A PG 2 WC Hematology SC Hematology GA 716TT UT WOS:000185045700226 ER PT J AU Redemann, J Masonis, SJ Schmid, B Anderson, TL Russell, PB Livingston, JM Dubovik, O Clarke, AD AF Redemann, J Masonis, SJ Schmid, B Anderson, TL Russell, PB Livingston, JM Dubovik, O Clarke, AD TI Clear-column closure studies of aerosols and water vapor aboard the NCAR C-130 during ACE-Asia, 2001 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE aerosol; water vapor; closure ID MID-ATLANTIC COAST; SUN PHOTOMETER MEASUREMENTS; LOWER TROPOSPHERIC AEROSOL; GROUND-BASED MEASUREMENTS; SINGLE-SCATTERING ALBEDO; OPTICAL-DEPTH SPECTRA; AIRBORNE IN-SITU; UNITED-STATES; LIGHT-ABSORPTION; SIZE DISTRIBUTIONS AB [1] Column closure studies are a tool to assess whether in situ and remote measurements of aerosol optical properties on a given aircraft are mutually consistent. In this paper we describe aerosol and water vapor column closure studies on the basis of instrumentation flown aboard the NCAR C-130 aircraft in the ACE-Asia field experiment in March - May 2001. For in situ observations, aerosol particles were sampled through a newly designed low-turbulence inlet (LTI). In 28 profiles extending to altitudes of up to 8 km, the in situ observations of scattering and absorption were compared to measurements with the six-channel NASA Ames Airborne Tracking Sun photometer (AATS-6). The comparison of Sun photometer and in situ-derived layer aerosol optical depth (AOD) at 550 nm showed agreement ( closure) within the measurement uncertainties in 25 out of 28 case studies. The average difference in layer AOD derived from the two methods was 0.03, corresponding to an average difference of 11.5%. The uncertainties in AATS-6-derived layer AOD ranged between 5 and 59% ( with a mean of 22%), and for the first time included an estimate for the uncertainty in layer AOD caused by possible horizontal variability in AOD encountered in the vertical profile. The average uncertainty in AATS-6-derived layer AOD due to possible horizontal variability alone was 19%. The uncertainties in in situ-derived layer AOD were between 10 and 55% ( with a mean of 19%). Stratification of the extinction closure data by ambient relative humidity ( RH) revealed that in situ-derived aerosol extinction at low ambient relative humidity (< 20% RH) tended to be slightly less than Sun photometer-derived aerosol extinction, while in situ-derived aerosol extinction at higher relative humidity was slightly greater than the Sun photometer-derived values. Stratification of the extinction closure data by the fine mode fraction of scattering indicated a modest enhancement of coarse mode extinction in the combined LTI/plumbing system. Analogous closure studies for layer water vapor and water vapor density showed that AATS-6 measured these quantities with very high accuracy, with correlation coefficients of 0.989 and 0.955 (rms differences of 10% and 33%), respectively. C1 Bay Area Environm Res Inst, Sonoma, CA 95476 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NASA, Goddard Earth Sci & Technol Ctr, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA. SRI Int, Menlo Pk, CA 94025 USA. RP Redemann, J (reprint author), Bay Area Environm Res Inst, 560 3rd St W, Sonoma, CA 95476 USA. EM jredemann@mail.arc.nasa.gov; sarahd@atmos.washington.edu; bschmid@mail.arc.nasa.gov; tadand@atmos.washington.edu; prussell@mail.arc.nasa.gov; jlivingston@mail.arc.nasa.gov; dubovik@aeronet.gsfc.nasa.gov; tclarke@soest.hawaii.edu RI Dubovik, Oleg/A-8235-2009; Doherty, Sarah/D-5592-2015 OI Dubovik, Oleg/0000-0003-3482-6460; Doherty, Sarah/0000-0002-7796-6968 NR 37 TC 46 Z9 47 U1 0 U2 2 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 AUG 30 PY 2003 VL 108 IS D23 AR 8655 DI 10.1029/2003JD003442 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 720GJ UT WOS:000185252800001 ER PT J AU Romanov, P Tarpley, D Gutman, G Carroll, T AF Romanov, P Tarpley, D Gutman, G Carroll, T TI Mapping and monitoring of the snow cover fraction over North America SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE fractional snow cover; satellite remote sensing ID CANOPY REFLECTANCE; WATER EQUIVALENT; LAND SURFACES; AVHRR DATA; ALBEDO; RESOLUTION; MODEL; ICE; RADIATION; PRODUCTS AB Automated snow maps over North America have been produced at the National Environmental Satellite Data and Information Service (NESDIS) of the National Oceanic and Atmospheric Administration (NOAA) since 1999. The developed snow-mapping system is based on observations in the visible, middle infrared, infrared, and microwave spectral bands from operational geostationary and polar orbiting meteorological satellites and generates daily maps of snow cover at a spatial resolution of 4 km. Recently, the existing snow-mapping technique was extended to derive the fractional snow cover. To obtain snow fraction, we use measurements of the Imager instrument on board Geostationary Operational Environmental Satellite (GOES). The algorithm treats every cloud-clear image pixel as a "mixed scene" consisting of a combination of snow-covered and snow-free land surface. To determine the portion of the pixel that is covered with snow, we employ a linear mixture approach, which relies on the Imager measurements in the visible spectral band. The estimated accuracy of subpixel snow fraction retrievals is about 10%. In this paper, we present a description of the snow cover and snow fraction mapping algorithms. Application of the developed algorithms over North America for three winter seasons from 1999-2000 to 2001-2002 has shown that the spatial distribution of the fractional snow cover over areas affected by seasonal snow closely corresponds to the distribution of the forest cover. The fraction of snow in the middle of the winter season generally varied from 100% over croplands, grasslands, and other nonforested areas to 20-30% over dense boreal forests. The snow fraction over dense boreal forests exhibited a slight intraseason variability; however, no obvious correlation of these changes with snowfalls was noticed. Over areas with no or sparse tree vegetation cover ( croplands, grasslands), snow fraction showed a noticeable correlation with snow depth for snow depths up to 35-40 cm. C1 NOAA, Off Res & Applicat, Natl Environm Satellite Data & Informat Serv, Camp Springs, MD 20746 USA. Colorado State Univ, Cooperat Inst Res Atmosphere, Ft Collins, CO 80523 USA. NASA Headquarters, Washington, DC 20546 USA. NOAA, Natl Operat Hydrol Remote Sensing Ctr, Natl Weather Serv, Chanhassen, MN 55317 USA. RP Romanov, P (reprint author), NOAA, Off Res & Applicat, Natl Environm Satellite Data & Informat Serv, World Weather Bldg,5200 Auth Rd,Room 712, Camp Springs, MD 20746 USA. EM peter.romanov@noaa.gov; dan.tarpley@noaa.gov; ggutman@nasa.gov; tc@nws.gov RI Romanov, Peter/F-5622-2010 OI Romanov, Peter/0000-0002-2153-8307 NR 46 TC 34 Z9 36 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 30 PY 2003 VL 108 IS D16 AR 8619 DI 10.1029/2002JD003142 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 720GA UT WOS:000185252000001 ER PT J AU Wang, J Christopher, SA Brechtel, F Kim, J Schmid, B Redemann, J Russell, PB Quinn, P Holben, BN AF Wang, J Christopher, SA Brechtel, F Kim, J Schmid, B Redemann, J Russell, PB Quinn, P Holben, BN TI Geostationary satellite retrievals of aerosol optical thickness during ACE-Asia SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ACE-Asia; GMS; geostationary satellites; aerosol retrieval; aerosol optical thickness; dynamic aerosol model ID SUN PHOTOMETER MEASUREMENTS; SKY RADIANCE MEASUREMENTS; GOES-8 IMAGER; SIZE DISTRIBUTION; ANTHROPOGENIC AEROSOLS; TROPOSPHERIC AEROSOL; ABSORBING AEROSOLS; RADIATIVE-TRANSFER; SULFATE AEROSOLS; COLUMN CLOSURE AB [1] Using 30 days of hourly geostationary satellite (GMS5 imager) data and discrete ordinate radiative transfer (DISORT) calculations, aerosol optical thickness (AOT) at 0.67 mum was retrieved over the west Pacific Ocean (20 degreesN - 45 degreesN, 110 degreesE - 150 degreesE) during the Aerosol Characterization Experiment (ACE-Asia) intensive observation period in April 2001. Different from previous one-channel retrieval algorithms, we have developed a strategy that utilizes in situ and ground measurements to characterize aerosol properties that vary both in space and time. Using Mie calculations and bilognormal size distribution parameters inferred from measurements, the relationship between Angstrom exponent ( a) and the ratio of two volume lognormal modes (gamma) was obtained. On the basis of spectral AOT values inferred from the Aerosol Robotic Network (AERONET) sites, NASA Ames Airborne Sun photometers (AATS6 and AATS14) and a Sun photometer on board a ship, a successive correction method (SCM) was used to infer the spatial distribution of a in the study area. Comparisons between the satellite-retrieved AOT and AERONET values over four sites show good agreement with linear coefficients ( R) of 0.86, 0.85, 0.86, and 0.87. The satellite-derived AOTs are also in good agreement with aircraft (R = 0.87) and ship measurements (R = 0.98). The average uncertainty in our AOT retrievals is about 0.08 with a maximum value of 0.15 mainly due to the assumptions in calibration (+/- 0.05), surface reflectance (+/- 0.01 - +/- 0.03), imaginary part of refractive index (+/- 0.05), and SCM-derived a values (+/- 0.02). The monthly mean AOT spatial distribution from GMS5 retrievals in April 2001 clearly shows the transport pattern of aerosols with high AOT near the coast of east Asia and low AOT over the open ocean. Using high temporal resolution satellite data, this paper demonstrates that the diurnal variation in AOT can be retrieved by current generations of geostationary satellites. The next generation of geostationary satellites with better spectral, spatial and radiometric resolution will significantly improve our ability to monitor aerosols and quantify their effects on regional climate. C1 Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35805 USA. Brechtel Mfg Inc, Hayward, CA 94544 USA. Meteorol Res Inst, Chungnam 357961, South Korea. Bay Area Environm Res Inst, Sonoma, CA 95476 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Wang, J (reprint author), Univ Alabama, Dept Atmospher Sci, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM wangjun@nsstc.uah.edu; sundar@nsstc.uah.edu; fredb@bnl.gov; jykim@metri.re.kr; bschmid@mail.arc.nasa.gov; jredemann@mail.arc.nasa.gov; prussell@mail.arc.nasa.gov; quinn@pmel.noaa.gov; brent@spamer.gsfc.nasa.gov RI Christopher, Sundar/E-6781-2011; Quinn, Patricia/R-1493-2016; Wang, Jun/A-2977-2008 OI Quinn, Patricia/0000-0003-0337-4895; Wang, Jun/0000-0002-7334-0490 NR 78 TC 24 Z9 24 U1 3 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 30 PY 2003 VL 108 IS D23 AR 8657 DI 10.1029/2003JD003580 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 720GJ UT WOS:000185252800002 ER PT J AU Markus, T Cavalieri, DJ Tschudi, MA Ivanoff, A AF Markus, T Cavalieri, DJ Tschudi, MA Ivanoff, A TI Comparison of aerial video and Landsat 7 data over ponded sea ice SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE aerial video; Landsat 7; ponded sea ice ID SURFACE ALBEDO; MELT PONDS; PARAMETERIZATION; DEPTH AB The development of melt ponds on Arctic sea ice during spring and summer is of great importance to the Arctic climate system as it accelerates the decay of the sea ice and greatly reduces the albedo. Both melt pond development and its spatial distribution are needed to understand the surface energy balance in summer. Previously, a technique was developed for classifying summer sea ice characteristics, including the amount of open water, white (snow-covered) ice, wet ice, and melt ponds using Landsat 7 Enhanced Thematic Mapper Plus (ETM+) spectral information. In this paper, we refine this technique through the use of airborne video data coincident with Landsat ETM+ imagery obtained over Baffin Bay on June 27, 2000. The video images, having a resolution of about 1.5 m at an aircraft altitude of 1.4 km, are classified into open water, ponded or wet ice, and unponded sea ice. Comparison of the video and Landsat imagery shows that many of the melt ponds are too small to cover an entire Landsat pixel (resolution of 30 in) so that the Landsat classification scheme would underestimate melt pond fraction. Thirteen high-resolution video images are classified to develop a method to calculate fractions of open water, ponded or wet ice, and unponded ice from Landsat 7 data. A comparison between these classified video images and Landsat retrievals yields a correlation coefficient of 0.95 with rms errors of less than 9% for the two ice types and 2% for open water. Comparisons of Landsat and video analyses not used in the development of the algorithm yield correlation coefficients of 0.87 for open water, 0.68 for ponded ice, and 0.78 for unponded ice. The rms differences are 10%, 8%, and 11 %, respectively. (C) 2003 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. Natl Ctr Atmospher Res, Atmospher Technol Div, Boulder, CO 80307 USA. Sci Syst & Applicat Inc, Lanham, MD USA. RP Markus, T (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Code 975, Greenbelt, MD 20771 USA. RI Markus, Thorsten/D-5365-2012 NR 18 TC 21 Z9 22 U1 0 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD AUG 30 PY 2003 VL 86 IS 4 BP 458 EP 469 DI 10.1016/S0034-4257(03)00124-X PG 12 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 711NW UT WOS:000184748800003 ER PT J AU Corp, LA McMurtrey, JE Middleton, EM Mulchi, CL Chappelle, EW Daughtry, CST AF Corp, LA McMurtrey, JE Middleton, EM Mulchi, CL Chappelle, EW Daughtry, CST TI Fluorescence sensing systems: In vivo detection of biophysical variations in field corn due to nitrogen supply SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE fluorescence imaging; carbon; nitrogen; precision agriculture; Zea mays L. ID LASER-INDUCED FLUORESCENCE; BLUE-GREEN FLUORESCENCE; CHLOROPHYLL-A FLUORESCENCE; REFLECTANCE MEASUREMENTS; NUTRIENT DEFICIENCIES; VEGETATION CANOPIES; EMISSION-SPECTRA; IMAGING-SYSTEM; PLANT-LEAVES; PHOTOSYNTHESIS AB Leaf and canopy fluorescence properties of field corn (Zea mays L.) grown under varying levels of nitrogen (N) fertilization were characterized to provide an improved N sensing capability which may assist growers in site-specific N management decisions. In vivo fluorescence emissions can occur in the wavelength region from 300 to 800 nm and are dependent on the wavelength of illumination. These light emissions have been grouped into five primary bands with maxima most frequently received from corn at 320 mn (UV), 450 nm (blue), 530 mn (green), 685 nm (red), and 740 nm (far-red). Two active fluorescence sensing systems have been custom developed; a leaf level Fluorescence Imaging System (FIS), and a canopy level Laser Induced Fluorescence Imaging System (LIFIS). FIS sequentially acquires high-resolution images of fluorescence emission bands under darkened laboratory conditions, while LIFIS simultaneously acquires four band images of plant canopies greater than or equal to1 m(2) under ambient sunlit conditions. Fluorescence emissions induced by these systems along with additional biophysical measures of crop condition; namely, chlorophyll content, N/C ratio, leaf area index (LAI), and grain yield, exhibited similar curvilinear responses to levels of supplied N. A number of significant linear correlations were found among band emissions and several band ratios versus measures of crop condition. Significant differences were obtained for several fluorescence band ratios with respect to the level of supplied N. Leaf adaxial versus abaxial surface emissions exhibited opposing trends with respect to the level of supplied N. Evidence supports that this confounding effect could be removed in part by the green/blue and green/red ratio images. The FIS and LIFIS active fluorescence sensor systems yielded results which support the underlying hypothesis that leaf and canopy fluorescence emissions are associated with other biophysical attributes of crop growth and this information could potentially assist in the site-specific management of variable-rate N fertilization programs. (C) 2003 Elsevier Inc. All rights reserved. C1 ARS, USDA, Hydrol & Remote Sensing Lab, Beltsville, MD 20705 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Univ Maryland, Dept Nat Resource Sci, College Pk, MD 20742 USA. RP Corp, LA (reprint author), ARS, USDA, Hydrol & Remote Sensing Lab, BARC W,Bldg 007,Room 104,10300 Baltimore Ave, Beltsville, MD 20705 USA. NR 35 TC 45 Z9 50 U1 4 U2 23 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD AUG 30 PY 2003 VL 86 IS 4 BP 470 EP 479 DI 10.1016/S0034-4257(03)00125-1 PG 10 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 711NW UT WOS:000184748800004 ER PT J AU Hall, DK Bayr, KJ Schoner, W Bindschadler, RA Chien, JYL AF Hall, DK Bayr, KJ Schoner, W Bindschadler, RA Chien, JYL TI Consideration of the errors inherent in mapping historical glacier positions in Austria from the ground and space (1893-2001) SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE mapping; glacier; Austria ID MASS-BALANCE; ICELAND; SCALE; ALPS AB The historical record of in situ measurements of the terminus positions of the Pasterze and Kleines Fleisskees glaciers in the eastern Alps of Austria is used to assess uncertainties in the measurement of decadal scale changes using satellite data. Topographic maps beginning in 1893, and satellite data from 1976 to 2001, were studied in concert with ground measurements to measure glacier changes. Ground measurements show that the tongue of the Pasterze Glacier receded similar to 1150 m from 1893 to 2001, while satellite-derived measurements, using August 2001 Landsat Enhanced Thematic Mapper Plus (ETM+) data registered to an 1893 topographic map, show a recession of 1300-1800 m, with an unknown error. The measurement accuracy depends on the registration technique and the pixel resolution of the sensor when two satellite images are used. When using topographic maps, an additional source of error is the accuracy of the glacier position shown on the map. Between 1976 and 2001, Landsat-derived measurements show a recession of the terminus of the Pasterze Glacier of 479 136 m (at an average rate of 19.1 m a(-1)) while measurements from the ground showed a recession of 428 m (at an average rate of 17.1 m a(-1)). Four-meter resolution Ikonos satellite images from 2000 and 2001 reveal a shrinkage of 22,096 +/- 46 m(2) in the Pasterze tongue. The nearby Kleines Fleisskees glacier lost 30% of its area between 1984 and 2001, and the area of exposed ice increased by 0.44 +/- 0.0023 km(2), according to Landsat satellite measurements. As more recent satellite images are utilized, especially data that are geocoded, the uncertainty associated with measuring glacier changes has decreased. It is not possible to assess the uncertainty when an old topographic map and a satellite image are coregistered. (C) 2003 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Keene State Coll, Dept Geog, Keene, NH 03435 USA. Cent Inst Meteorol & Geodynam, ZAMG, Klimaabt, A-1190 Vienna, Austria. Gen Sci Corp, Laurel, MD 20707 USA. RP Hall, DK (reprint author), NASA, Goddard Space Flight Ctr, Code 974, Greenbelt, MD 20771 USA. RI Hall, Dorothy/D-5562-2012; OI Schoner, Wolfgang/0000-0001-6546-0639 NR 30 TC 103 Z9 142 U1 7 U2 23 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD AUG 30 PY 2003 VL 86 IS 4 BP 566 EP 577 DI 10.1016/S0034-4257(03)00134-2 PG 12 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 711NW UT WOS:000184748800012 ER PT J AU Chandler, MO Moore, TE AF Chandler, MO Moore, TE TI Observations of the geopause at the equatorial magnetopause: Density and temperature SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PLASMASPHERIC MATERIAL; MODEL AB [1] Magnetic flux tubes containing plasmaspheric ion density and composition have been observed in the region between the classical plasmapause and the magnetopause. New observations show that these ion distributions exist at the equatorial, post-noon magnetopause. Comparison to observations of similar distributions at geosynchronous orbit and to simulations leads to the conclusion that these ions are convected from these regions to the magnetopause. This represents an extension of the geopause to the outer edge of the magnetosphere on the dayside. The presence of ion densities > 10 cm(-3) in this region must have profound impact on the nature of plasma processes that occur there. C1 NASA, MSFC, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. NASA, Goddard Space Flight Ctr, Interplanetary Phys Branch, LEP, Greenbelt, MD 20771 USA. RP Chandler, MO (reprint author), NASA, MSFC, Natl Space Sci & Technol Ctr, Code SD50, Huntsville, AL 35805 USA. RI Moore, Thomas/D-4675-2012 OI Moore, Thomas/0000-0002-3150-1137 NR 13 TC 18 Z9 18 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 29 PY 2003 VL 30 IS 16 AR 1869 DI 10.1029/2003GL017611 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 720FJ UT WOS:000185250500004 ER PT J AU Murayama, T Masonis, SJ Redemann, J Anderson, TL Schmid, B Livingston, JM Russell, PB Huebert, B Howell, SG McNaughton, CS Clarke, A Abo, M Shimizu, A Sugimoto, N Yabuki, M Kuze, H Fukagawa, S Maxwell-Meier, K Weber, RJ Orsini, DA Blomquist, B Bandy, A Thornton, D AF Murayama, T Masonis, SJ Redemann, J Anderson, TL Schmid, B Livingston, JM Russell, PB Huebert, B Howell, SG McNaughton, CS Clarke, A Abo, M Shimizu, A Sugimoto, N Yabuki, M Kuze, H Fukagawa, S Maxwell-Meier, K Weber, RJ Orsini, DA Blomquist, B Bandy, A Thornton, D TI An intercomparison of lidar-derived aerosol optical properties with airborne measurements near Tokyo during ACE-Asia SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE polarization and Raman lidar; airborne measurement; Asian dust ID TO-BACKSCATTER RATIO; RAMAN LIDAR; IN-SITU; AIRCRAFT MEASUREMENTS; TROPOSPHERIC AEROSOL; 180-DEGREES BACKSCATTER; MULTIWAVELENGTH LIDAR; POLARIZATION LIDAR; VERTICAL STRUCTURE; INDIAN-OCEAN AB During the ACE-Asia intensive observation period (IOP), an intercomparison experiment with ground-based lidars and aircraft observations was conducted near Tokyo. On 23 April 2001, four Mie backscatter lidars were simultaneously operated in the Tokyo region, while the National Center for Atmospheric Research C-130 aircraft flew a stepped-ascent profile between the surface and 6 km over Sagami Bay southwest of Tokyo. The C-130 observation package included a tracking Sun photometer and in situ packages measuring aerosol optical properties, aerosol size distribution, aerosol ionic composition, and SO2 concentration. The three polarization lidars suggested that the observed modest concentrations of Asian dust in the free troposphere extended up to an altitude of 8 km. We found a good agreement in the backscattering coefficient at 532 nm among lidars and in situ 180degrees backscatter nephelometer observations. The intercomparison indicated that the aerosol layer between 1.6 and 3.5 km was a remarkably stable and homogenous in mesoscale. We also found reasonable agreement between the aerosol extinction coefficients (sigma(a) similar to 0.03 km(-1)) derived from the airborne tracking Sun photometer, in situ optical instruments, and those estimated from the lidars above the planetary boundary layer (PBL). We also found considerable vertical variation of the aerosol depolarization ratio (delta(a)) and a negative correlation between delta(a) and the backscattering coefficient (delta(a)) below 3.5 km. Airborne measurements of size-dependent optical parameters (e.g., the fine mode fraction of scattering) and of aerosol ionic compositions suggests that the mixing ratio of the accumulation-mode and coarse-mode ( dust) aerosols was primarily responsible for the observed variation of delta(a). Aerosol observations during the intercomparison period captured the following three types of layers in the atmosphere: a PBL ( surface to 1.2-1.5 km) where fine (mainly sulfate) particles with a low delta(a) (< 10%) dominated; an intermediate layer (between the top of the PBL and 3.5 km) where fine particles and dust particles were moderately externally mixed, giving moderate delta(a); and an upper layer (above similar to 3.5 km) where dust dominated, giving a high delta(a) (30%). A substantial dust layer between 4.5 and 6.5 km was observed just west of Japan by the airborne instruments and found to have a lidar ratio of 50.4 +/- 9.4 sr. This agrees well with nighttime Raman lidar measurements made later on this same dust layer as it passed over Tokyo, which found a lidar ratio of 46.5 +/- 10.5 sr. C1 Tokyo Univ Mercantile Marine, Tokyo 1358533, Japan. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Bay Area Environm Res Inst, Sonoma, CA 95476 USA. SRI Int, Menlo Pk, CA 94025 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA. Tokyo Metropolitan Univ, Dept Elect Engn, Tokyo 1920397, Japan. Natl Inst Environm Studies, Div Atmospher Environm, Tsukuba, Ibaraki 3058506, Japan. Chiba Univ, Ctr Environm Remote Sensing, Inage Ku, Chiba 2638522, Japan. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA. RP Tokyo Univ Mercantile Marine, 2-1-6 Etchujima, Tokyo 1358533, Japan. EM murayama@ipc.tosho-u.ac.jp; sarahd@atmos.washington.edu; jredemann@mail.arc.nasa.gov; tadand@atmos.washington.edu; bschmid@mail.arc.nasa.gov; jlivingston@mail.arc.nasa.gov; prussell@mail.arc.nasa.gov; huebert@hawaii.edu; showell@soest.hawaii.edu; cameronm@soest.hawaii.edu; tclarke@soest.hawaii.edu; abo@eei.metro-u.ac.jp; shimizua@nies.go.jp; nsugimot@nies.go.jp; yabuki@pmg.nipr.ac.jp; hkuze@ceres.cr.chiba-u.ac.jp; shun@ceres.cr.chiba-u.ac.jp; kmaxwell@eas.gatech.edu; rweber@eas.gatech.edu; douglas.orsini@eas.gatech.edu; blomquis@hawaii.edu; bandyar@drexel.edu; dct@drexel.edu RI Shimizu, Atsushi/C-2810-2009; Doherty, Sarah/D-5592-2015 OI Shimizu, Atsushi/0000-0002-7306-7412; Doherty, Sarah/0000-0002-7796-6968 NR 57 TC 50 Z9 51 U1 1 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 29 PY 2003 VL 108 IS D23 AR 8651 DI 10.1029/2002JD003259 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 720GH UT WOS:000185252700001 ER PT J AU Li, JZ Ning, CZ AF Li, JZ Ning, CZ TI Interplay of collective excitations in quantum-well intersubband resonances SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRON-GAS; TRANSITIONS; EXCHANGE; TEMPERATURE; DENSITY AB Intersubband resonances in a semiconductor quantum well (QW) display fascinating features involving various collective excitations such as Fermi-edge singularity (FES) and intersubband plasmon (ISP). Using a density matrix approach, we treated many-body effects such as depolarization, vertex correction, and self-energy consistently for a two-subband system. We found a systematic change in resonance spectra from FES- to ISP-dominated features, as QW width or electron density is varied. Such an interplay between FES and ISP significantly changes both line shape and peak position of the absorption spectrum. We found that a cancellation of FES and ISP undresses the resonant responses and recovers the single-particle features of absorption for semiconductors with a strong nonparabolicity such as InAs, leading to a dramatic broadening of the absorption spectrum. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Li, JZ (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Mail Stop N229-1, Moffett Field, CA 94035 USA. RI Ning, C. Z./D-4699-2009 OI Ning, C. Z./0000-0003-4583-8889 NR 26 TC 45 Z9 46 U1 0 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 AUG 29 PY 2003 VL 91 IS 9 AR 097401 DI 10.1103/PhysRevLett.91.097401 PG 4 WC Physics, Multidisciplinary SC Physics GA 719ZJ UT WOS:000185235000047 PM 14525208 ER PT J AU Singh, HB Tabazadeh, A Evans, MJ Field, BD Jacob, DJ Sachse, G Crawford, JH Shetter, R Brune, WH AF Singh, HB Tabazadeh, A Evans, MJ Field, BD Jacob, DJ Sachse, G Crawford, JH Shetter, R Brune, WH TI Oxygenated volatile organic chemicals in the oceans: Inferences and implications based on atmospheric observations and air-sea exchange models SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TROPOSPHERE AB [1] Airborne measurements of oxygenated volatile organic chemicals (OVOC), OH free radicals, and tracers of pollution were performed over the Pacific during Winter/ Spring of 2001. We interpret atmospheric observations of acetaldehyde, propanal, methanol, and acetone with the help of a global 3-D model and an air-sea exchange model to assess their oceanic budgets. We infer that surface waters of the Pacific are greatly supersaturated with acetaldehyde and propanal. Bulk surface seawater concentration of 7 nM (10(-9) mol L-1) and 2 nM and net fluxes of 1.1 x 10(-12) g cm(-2) s(-1) and 0.4 x 10(-12) g cm(-2) s(-1) are calculated for acetaldehyde and propanal, respectively. Large surface seawater concentrations are also estimated for methanol ( 100 nM) and acetone ( 10 nM) corresponding to an undersaturation of 6% and 14%, and a deposition velocity of 0.08 cm s(-1) and 0.10 cm s(-1), respectively. These data imply a large oceanic source for acetaldehyde and propanal, and a modest sink for methanol and acetone. Assuming a 50 - 100 meter mixed layer, an extremely large oceanic reservoir of OVOC, exceeding the atmospheric reservoir by an order of magnitude, can be inferred to be present. Available seawater data are both preliminary and extremely limited but indicate rather low bulk OVOC concentrations and provide no support for the existence of a large oceanic reservoir. We speculate on the causes and implications of these findings. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Harvard Univ, Cambridge, MA 02138 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Penn State Univ, University Pk, PA 16802 USA. RP Singh, HB (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RI Crawford, James/L-6632-2013; Evans, Mathew/A-3886-2012 OI Crawford, James/0000-0002-6982-0934; Evans, Mathew/0000-0003-4775-032X NR 19 TC 57 Z9 57 U1 3 U2 15 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD AUG 28 PY 2003 VL 30 IS 16 AR 1862 DI 10.1029/2003GL017933 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 720FF UT WOS:000185250200004 ER PT J AU Chin, M Ginoux, P Lucchesi, R Huebert, B Weber, R Anderson, T Masonis, S Blomquist, B Bandy, A Thornton, D AF Chin, M Ginoux, P Lucchesi, R Huebert, B Weber, R Anderson, T Masonis, S Blomquist, B Bandy, A Thornton, D TI A global aerosol model forecast for the ACE-Asia field experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE ACE-Asia; forecast; global model ID GOCART MODEL; DUST AEROSOL; SATELLITE AB We present the results of aerosol forecast during the ACE-Asia field experiment in spring 2001, using the Georgia Tech/Goddard Global Ozone Chemistry Aerosol Radiation and Transport ( GOCART) model and the meteorological forecast fields from the Goddard Earth Observing System Data Assimilation System (GEOS DAS). The model provides direct information on aerosol optical thickness and concentrations for effective flight planning, while feedbacks from measurements constantly evaluate the model for successful model improvements. We verify the model forecast skill by comparing model-predicted aerosol quantities and meteorological variables with those measured by the C-130 aircraft. The GEOS DAS meteorological forecast system shows excellent skills in predicting winds, relative humidity, and temperature, with skill scores usually in the range of 0.7-0.99. The model is also skillful in forecasting pollution aerosols, with most scores above 0.5. The model correctly predicted the dust outbreak events and their trans-Pacific transport, but it constantly missed the high dust concentrations observed in the boundary layer. We attribute this "missing" dust source to desertification regions in the Inner Mongolia Province in China, which have developed in recent years but were not included in the model during forecasting. After incorporating the desertification sources, the model is able to reproduce the observed boundary layer high dust concentrations over the Yellow Sea. We demonstrate that our global model can not only account for the large-scale intercontinental transport but also produce the small-scale spatial and temporal variations that are adequate for aircraft measurements planning. C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. Sci Applicat Int Corp, Beltsville, MD USA. NASA, Data Assimilat Off, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA. Univ Washington, Dept Atmospher Sci, Seattle, WA 98195 USA. Drexel Univ, Dept Chem, Philadelphia, PA 19104 USA. RP NASA, Atmospher Chem & Dynam Branch, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA. EM chin@rondo.gsfc.nasa.gov; pag@gfdl.noaa.gov; rlucchesi@dao.gsfc.nasa.gov; huebert@hawaii.edu; rweber@eas.gatech.edu; tadand@atmos.washington.edu; sarahd@atmos.washington.edu; blomquis@hawaii.edu; bandyar@drexel.edu; dct@drexel.edu RI Ginoux, Paul/C-2326-2008; Chin, Mian/J-8354-2012; Doherty, Sarah/D-5592-2015 OI Ginoux, Paul/0000-0003-3642-2988; Doherty, Sarah/0000-0002-7796-6968 NR 25 TC 62 Z9 62 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 28 PY 2003 VL 108 IS D23 AR 8654 DI 10.1029/2003JD003642 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 720GG UT WOS:000185252600001 ER PT J AU Kanzawa, H Sugita, T Nakajima, H Bodeker, GE Oelhaf, H Stowasser, M Wetzel, G Engel, A Schmidt, U Levin, I Toon, GC Sen, B Blavier, JF Aoki, S Nakazawa, T Jucks, KW Johnson, DG Traub, WA Camy-Peyret, C Payan, S Jeseck, P Murata, I Fukunishi, H von Konig, M Bremer, H Kullmann, H Park, JH Pan, LL Yokota, T Suzuki, M Shiotani, M Sasano, Y AF Kanzawa, H Sugita, T Nakajima, H Bodeker, GE Oelhaf, H Stowasser, M Wetzel, G Engel, A Schmidt, U Levin, I Toon, GC Sen, B Blavier, JF Aoki, S Nakazawa, T Jucks, KW Johnson, DG Traub, WA Camy-Peyret, C Payan, S Jeseck, P Murata, I Fukunishi, H von Konig, M Bremer, H Kullmann, H Park, JH Pan, LL Yokota, T Suzuki, M Shiotani, M Sasano, Y TI Validation and data characteristics of nitrous oxide and methane profiles observed by the Improved Limb Atmospheric Spectrometer (ILAS) and processed with the Version 5.20 algorithm SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE nitrous oxide; methane; polar stratosphere; validation; satellite sensor; Improved Limb Atmospheric Spectrometer (ILAS) ID TUNABLE DIODE-LASER; TRACE GAS OBSERVATIONS; POLAR VORTEX; LOWER STRATOSPHERE; HETERODYNE SPECTROMETER; RETRIEVAL ALGORITHM; POTENTIAL VORTICITY; UPPER TROPOSPHERE; CH4 MEASUREMENTS; ARCTIC VORTEX AB Vertical profiles of nitrous oxide and methane at high latitudes (57-72degreesN; 64-89degreesS) were observed by the Improved Limb Atmospheric Spectrometer (ILAS) solar occultation sensor aboard Advanced Earth Observing Satellite. These measurements were made continuously from November 1996 through June 1997 with some additional periods in September-October 1996. A validation study of the nitrous oxide and methane data processed with the Version 5.20 ILAS retrieval algorithm is presented in this paper. Comparisons are made with (1) nitrous oxide and methane obtained by the ILAS validation balloon campaigns at Kiruna, Sweden, and at Fairbanks, Alaska, in the Arctic; (2) nitrous oxide and methane by the Photochemistry of Ozone Loss in the Arctic Region in Summer aircraft campaign in the Arctic; (3) nitrous oxide by the ground-based spectroscopic measurements and by the aircraft-based remote sensing measurements in the Arctic; and (4) methane by satellite measurements of the Version 19 Halogen Occultation Experiment in the Arctic and Antarctic. Comparisons of ILAS nitrous oxide and methane with Upper Atmosphere Research Satellite Reference Atmosphere data are also made. The results of the comparisons and additional ILAS internal consistency analyses are as follows: (1) the uncertainty of ILAS nitrous oxide is better than 10% over 10-30 km in altitude, and is larger than 50% over 30-40 km, which is comparable to the expected total errors of the ILAS measurements; (2) the uncertainty of ILAS methane is better than 10% over 10-50 km, except for 15-30 km in winter with positive biases exceeding 20%, which is smaller than or comparable to the expected total errors of the ILAS measurements (the quality of ILAS methane in the polar lower stratosphere is better in summer than in winter). In summary, the characteristics of ILAS measurements, i.e., high sampling frequency in polar latitudes with high vertical resolution, along with the good quality of ILAS Version 5.20 nitrous oxide for 10-40 km and the good quality of ILAS Version 5.20 methane for 10-50 km except for 15-30 km in winter, make the ILAS nitrous oxide and methane data set valuable for scientific study of various polar stratospheric phenomena. C1 Natl Inst Environm Studies, Tsukuba, Ibaraki 3050053, Japan. Natl Inst Water & Atmospher Res, Lauder, New Zealand. Univ Karlsruhe, Forschungszentrum Karlsruhe, Inst Meteorol & Klimaforsch, D-76021 Karlsruhe, Germany. Univ Frankfurt, Inst Meteorol, D-60054 Frankfurt, Germany. Univ Heidelberg, Inst Umweltphys, D-69120 Heidelberg, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Tohoku Univ, Grad Sch Sci, Ctr Atmospher & Ocean Studies, Sendai, Miyagi 9808578, Japan. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Paris 06, CNRS, Lab Phys Mol & Applicat, F-75252 Paris 05, France. Tohoku Univ, Grad Sch Sci, Dept Geophys, Sendai, Miyagi 9808578, Japan. Univ Bremen, Inst Umweltphys, D-28359 Bremen, Germany. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Hokkaido Univ, Grad Sch Environm Earth Sci, Sapporo, Hokkaido 060, Japan. RP Kanzawa, H (reprint author), Nagoya Univ, Grad Sch Environm Studies, Dept Hydrospher Atmospher Sci, Div Earth & Environm Sci,Chikusa Ku, Furo Cho, Nagoya, Aichi 4648601, Japan. EM kanzawa@ihas.nagoya-u.ac.jp; tsugita@nies.go.jp; hide@nies.go.jp; g.bodeker@niwa.co.nz; hermann.oelhaf@imk.fzk.de; markus.stowasser@imk.fzk.de; gerald.wetzel@imk.fzk.de; an.engel@meteor.uni-frankfurt.de; u.schmidt@meteor.uni-frankfurt.de; ingeborg.levin@iup.uni-heidelberg.de; aoki@mail.cc.tohoku.ac.jp; nakazawa@mail.cc.tohoku.ac.jp; kjucks@cfa.harvard.edu; d.g.johnson@larc.nasa.gov; wtraub@cfa.harvard.edu; murata@pat.geophys.tohoku.ac.jp; fuku@pat.geophys.tohoku.ac.jp; miriam@florian.physik.uni-bremen.de; bremer@florian.physik.uni-bremen.de; hkuell@uni-bremen.de; j.h.park@larc.nasa.gov; liwen@ucar.edu; yoko@nies.go.jp; suzuki@eorc.nasda.go.jp; shiotani@kurasc.kyoto-u.ac.jp; sasano@nies.go.jp RI Pan, Laura/A-9296-2008; Sasano, Yasuhiro/C-2927-2009; Wetzel, Gerald/A-7065-2013; Sinnhuber, Miriam/A-7252-2013; Oelhaf, Hermann/A-7895-2013; Engel, Andreas/E-3100-2014 OI Pan, Laura/0000-0001-7377-2114; Sasano, Yasuhiro/0000-0001-7470-5642; Engel, Andreas/0000-0003-0557-3935 NR 68 TC 20 Z9 20 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 AUG 28 PY 2003 VL 108 IS D16 AR 8003 DI 10.1029/2002JD002458 PG 35 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 720FV UT WOS:000185251500001 ER PT J AU Parthiban, S Lee, TJ Guha, S Francisco, JS AF Parthiban, S Lee, TJ Guha, S Francisco, JS TI Theoretical study of chlorine nitrates: Implications for stratospheric chlorine chemistry SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID GAUSSIAN-BASIS SETS; VIBRATIONAL-SPECTRA; MICROWAVE-SPECTRUM; TEMPERATURE-DEPENDENCE; MOLECULAR CALCULATIONS; THERMAL-DECOMPOSITION; RELATIVE STABILITIES; ELECTRONIC-STRUCTURE; BROMINE CHEMISTRY; COUPLED-CLUSTER AB Reported here is a theoretical study of possible stratospheric chlorine reservoir species including isomers of chemical formula ClNO4 and ClNO5, in addition to the well-known ClONO2 reservoir species. Density functional theory (DFT) in conjunction with large one-particle basis sets has been used to determine equilibrium structures, dipole moments, rotational constants, harmonic vibrational frequencies, and infrared intensities. The B3LYP functional was used since it has previously been shown to perform well for similar compounds. The equilibrium geometry and vibrational spectra of ClONO2 are shown to be in good agreement with the experimental data and also with high-level coupled-cluster calculations reported previously. Three stable isomers have been identified for each ClNO4 and ClNO5. The vibrational spectrum of O2ClONO2 has been compared with the available experimental data and found to be in good agreement. The relative energetics of the ClNO4 and ClNO5 isomers have been determined using large atomic natural orbital (ANO) basis sets in conjunction with the singles and doubles coupled-cluster method that includes a perturbational correction for triple excitations, denoted CCSD(T). Accurate heats of formation have been evaluated by computing energies for isodesmic reactions involving the ClNO4 and ClNO5 isomers. The stability of these molecules with respect to thermal dissociation is examined. The present study suggests that isomers of ClNO4 and ClNO5 may have no atmospheric chemical relevance because the atmospheric concentrations of the necessary reactants are insufficent, but it is also found that under laboratory conditions the formation of O2ClONO2 cannot be ignored. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. RP Lee, TJ (reprint author), NASA, Ames Res Ctr, MST27B-1, Moffett Field, CA 94035 USA. RI Lee, Timothy/K-2838-2012 NR 66 TC 3 Z9 4 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD AUG 27 PY 2003 VL 125 IS 34 BP 10446 EP 10458 DI 10.1021/ja010297g PG 13 WC Chemistry, Multidisciplinary SC Chemistry GA 714ND UT WOS:000184919600053 PM 12926970 ER PT J AU Ciftcioglu, N McKay, DS Kajander, EO AF Ciftcioglu, N McKay, DS Kajander, EO TI Association between nanobacteria and periodontal disease SO CIRCULATION LA English DT Letter C1 NASA, Johnson Space Ctr, Univ Space Res Assoc, Houston, TX 77058 USA. Univ Kuopio, Dept Biochem, FIN-70211 Kuopio, Finland. RP Ciftcioglu, N (reprint author), NASA, Johnson Space Ctr, Univ Space Res Assoc, Houston, TX 77058 USA. NR 5 TC 12 Z9 13 U1 0 U2 2 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0009-7322 J9 CIRCULATION JI Circulation PD AUG 26 PY 2003 VL 108 IS 8 BP E58 EP E58 DI 10.1161/01.CIR.0000086781.16968.2D PG 1 WC Cardiac & Cardiovascular Systems; Peripheral Vascular Disease SC Cardiovascular System & Cardiology GA 715DH UT WOS:000184954900028 PM 12939248 ER PT J AU Cho, JYN Newell, RE Anderson, BE Barrick, JDW Thornhill, KL AF Cho, JYN Newell, RE Anderson, BE Barrick, JDW Thornhill, KL TI Characterizations of tropospheric turbulence and stability layers from aircraft observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE clear air turbulence; stable layers; tracer mixing; shear instability; convective instability ID MARINE BOUNDARY-LAYER; ATMOSPHERE; STRATOSPHERE; TEMPERATURE; POLLUTION; SHEETS; WAVES; RADAR AB [1] Velocity, temperature, and specific humidity data collected by aircraft at 20-Hz resolution are analyzed for stability and turbulence parameters. Over 100 vertical profiles ( mostly over the ocean) with a total of over 300 km in vertical airspace sampled are used. The compiled statistics show that anisotropy in the velocity fluctuations prevail down to the smallest spatial separations measured. A partitioning of convective versus dynamical instability indicates that in the free troposphere, the ratio of shear-produced turbulence to convectively produced turbulence increases from roughly 2: 1 for weak turbulence (epsilon < 10(-4) m(2) s(-3)) to perhaps 3: 1 for strong turbulence (epsilon > 10(-4) m(2) s(-3)). For the boundary layer, this ratio is close to 1: 1 for weak turbulence and roughly 2: 1 for strong turbulence. There is also a correlation between the strength of the vertical shear in horizontal winds and the turbulence intensity. In the free troposphere the turbulence intensity is independent of the degree of static stability, whereas in the boundary layer the turbulence intensity increases with a fall in static stability. Vertical humidity gradients correlate with static stability for strong humidity gradients, which supports the basic notion that stable layers impede vertical mixing of trace gases and aerosols. Vertical shear correlates with vertical humidity gradient, so it appears that the effect of differential advection creating tracer gradients dominates the effect of differential advection destroying tracer gradients through shear-induced turbulence. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. RP Cho, JYN (reprint author), MIT, Lincoln Lab, 244 Wood St, Lexington, MA 02420 USA. EM jync@mit.edu; renewell@mit.edu; b.e.anderson@larc.nasa.gov; j.d.barrick@larc.nasa.gov; k.l.thornhill@larc.nasa.gov NR 26 TC 28 Z9 28 U1 0 U2 4 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 AUG 26 PY 2003 VL 108 IS D20 AR 8784 DI 10.1029/2002JD002820 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 720GB UT WOS:000185252100001 ER PT J AU Kolokolov, KI Ning, CZ AF Kolokolov, KI Ning, CZ TI Doping-induced type-II to type-I transition and interband optical gain in InAs/AlSb quantum wells SO APPLIED PHYSICS LETTERS LA English DT Article ID PHOTOLUMINESCENCE; HETEROSTRUCTURES AB We show that proper doping of the barrier regions can convert the well-known type-II InAs/AlSb quantum wells (QWs) to type I, producing strong interband transitions comparable to regular type-I QWs. The interband gain for TM mode is as high as 4000 1/cm, thus providing an important alternative material system in the midinfrared wavelength range. We also study the TE and TM gain as functions of doping level and intrinsic electron-hole density. (C) 2003 American Institute of Physics. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Ning, CZ (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, MS N229-1, Moffett Field, CA 94035 USA. RI Ning, C. Z./D-4699-2009 OI Ning, C. Z./0000-0003-4583-8889 NR 12 TC 2 Z9 2 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 25 PY 2003 VL 83 IS 8 BP 1581 EP 1583 DI 10.1063/1.1605236 PG 3 WC Physics, Applied SC Physics GA 713EN UT WOS:000184844100029 ER PT J AU Andriotis, AN Srivastava, D Menon, M AF Andriotis, AN Srivastava, D Menon, M TI Comment on "Intrinsic electron transport properties of carbon nanotube Y-junctions" [Appl. Phys. Lett. 81, 5234 (2002)] SO APPLIED PHYSICS LETTERS LA English DT Editorial Material ID DEVICES C1 Fdn Res & Technol Hellas, Inst Elect Struct & Laser, Iraklion 71110, Crete, Greece. NASA, Ames Res Ctr, CSC, Moffett Field, CA 94035 USA. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. Univ Kentucky, Ctr Computat Sci, Lexington, KY 40506 USA. RP Andriotis, AN (reprint author), Fdn Res & Technol Hellas, Inst Elect Struct & Laser, POB 1527, Iraklion 71110, Crete, Greece. EM andriot@iesl.forth.gr; deepak@nas.nasa.gov; super250@pop.uky.edu RI Andriotis, Antonios/A-2848-2014; OI Zacharia, Thomas/0000-0001-6463-5425 NR 25 TC 9 Z9 9 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD AUG 25 PY 2003 VL 83 IS 8 BP 1674 EP 1675 DI 10.1063/1.1604948 PG 2 WC Physics, Applied SC Physics GA 713EN UT WOS:000184844100060 ER PT J AU Sumwalt, RL Thomas, RJ Dismukes, K AF Sumwalt, RL Thomas, RJ Dismukes, K TI New last line of defense against aviation accidents SO AVIATION WEEK & SPACE TECHNOLOGY LA English DT Editorial Material C1 Air Line Pilots Assn, Human Factors & Training Grp, Herndon, VA 20170 USA. US Airways Corp, Flight Training & Stand, Washington, DC 20001 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Sumwalt, RL (reprint author), Air Line Pilots Assn, Human Factors & Training Grp, Herndon, VA 20170 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MCGRAW HILL INC PI NEW YORK PA 1221 AVENUE OF THE AMERICAS, NEW YORK, NY 10020 USA SN 0005-2175 J9 AVIAT WEEK SPACE TEC JI Aviat. Week Space Technol. PD AUG 25 PY 2003 VL 159 IS 8 BP 66 EP 66 PG 1 WC Engineering, Aerospace SC Engineering GA 715TD UT WOS:000184987600026 ER PT J AU Fahay, MP Nielsen, JG AF Fahay, MP Nielsen, JG TI Ontogenetic evidence supporting a relationship between Brotulotaenia and Lamprogrammus (Ophidiiformes : Ophidiidae) based on the morphology of exterilium and rubaniform larvae SO ICHTHYOLOGICAL RESEARCH LA English DT Article DE Ophidiidae; Brotulaenia; Lamprogrammus; larvae ID FISH; ATLANTIC; PISCES AB Analysis of the "Dana" collection of larval fishes yielded 36 exterilium larvae and 17 rubaniform larvae, referable to the Ophidiidae. Both larval types reach large sizes before transformation and are characterized by an exterilium gut, although it is less strongly expressed in rubaniform larvae. Both have early-forming, elongate, descending processes of the coracoid that serve to support the trailing intestines. Both have a greatly reduced pelvic girdle attached to a stalklike cartilaginous structure, resulting in a pelvic fin origin well posterior to the cleithral symphysis, a position that is without precedent in the family Ophidiidae. Both of these larval types also strongly display an anterior to posterior developmental sequence, lose the pelvic fin rays at transformation, and have extraordinarily elongate proximal radials supporting their dorsal and anal fins and modified proximal radials supporting the anterior dorsal fin rays. After examination of these larvae and reference to 5 previously described exterilium larvae and I previously described rubaniform larva. we conclude that they belong to Lamprogrammus (three species) and Brotulotaenia (four species), respectively. The most recent classification of the Ophidiidae places Brotulotaenia in the monotypic subfamily Brotulotaeniinae, and Lamprogrammus in the subfamily Neobythitinae along with 37 other genera. The latter subfamily is an unwieldy assemblage for which monophyly has never been established. Ontogenetic evidence suggests a closer relationship between Brotulotaenia and Lamprogrammus, and the most economical reorganization of the ophidiids would involve incorporating the latter genus into the Brotulotaeniinae. C1 NOAA, Natl Marine Fisheries Serv, NE Fishery Sci Ctr, Sandy Hook Lab, Highlands, NJ 07732 USA. Univ Copenhagen, Zool Museum, DK-2100 Copenhagen, Denmark. RP Fahay, MP (reprint author), NOAA, Natl Marine Fisheries Serv, NE Fishery Sci Ctr, Sandy Hook Lab, Highlands, NJ 07732 USA. NR 32 TC 8 Z9 12 U1 0 U2 0 PU SPRINGER-VERLAG TOKYO PI TOKYO PA 3-3-13, HONGO, BUNKYO-KU, TOKYO, 113-0033, JAPAN SN 1341-8998 J9 ICHTHYOL RES JI Ichthyol. Res. PD AUG 25 PY 2003 VL 50 IS 3 BP 209 EP 220 DI 10.1007/s10228-003-0159-5 PG 12 WC Zoology SC Zoology GA 719KQ UT WOS:000185202600001 ER PT J AU Anderson, JD Mashhoon, B AF Anderson, JD Mashhoon, B TI Pioneer anomaly and the helicity-rotation coupling SO PHYSICS LETTERS A LA English DT Article DE pioneer anomaly; helcity-rotation coupling AB The modification of the Doppler effect due to the coupling of the helicity of the radiation with the rotation of the source/receiver is considered in the case of the Pioneer 10/11 spacecraft. We explain why the Pioneer anomaly is not influenced by the helicity-rotation coupling. (C) 2003 Elsevier B.V. All rights reserved. C1 Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mashhoon, B (reprint author), Univ Missouri, Dept Phys & Astron, Columbia, MO 65211 USA. NR 7 TC 20 Z9 20 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD AUG 25 PY 2003 VL 315 IS 3-4 BP 199 EP 202 DI 10.1016/S0375-9601(03)01040-5 PG 4 WC Physics, Multidisciplinary SC Physics GA 716BG UT WOS:000185008500007 ER PT J AU Newchurch, MJ Yang, ES Cunnold, DM Reinsel, GC Zawodny, JM Russell, JM AF Newchurch, MJ Yang, ES Cunnold, DM Reinsel, GC Zawodny, JM Russell, JM TI Evidence for slowdown in stratospheric ozone loss: First stage of ozone recovery SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article DE stratospheric ozone trends; CFCs; Montreal Protocol ID HALOGEN OCCULTATION EXPERIMENT; LOWER MESOSPHERE; MIDDLE ATMOSPHERE; WATER-VAPOR; GLOBAL QBO; UARS DATA; TRENDS; CHLORINE; MODEL; O-3 AB Global ozone trends derived from the Stratospheric Aerosol and Gas Experiment I and II (SAGE I/II) combined with the more recent Halogen Occultation Experiment (HALOE) observations provide evidence of a slowdown in stratospheric ozone losses since 1997. This evidence is quantified by the cumulative sum of residual differences from the predicted linear trend. The cumulative residuals indicate that the rate of ozone loss at 35 45 km altitudes globally has diminished. These changes in loss rates are consistent with the slowdown of total stratospheric chlorine increases characterized by HALOE HCl measurements. These changes in the ozone loss rates in the upper stratosphere are significant and constitute the first stage of a recovery of the ozone layer. C1 Univ Alabama, NSSTC, Dept Atmospher Sci, Huntsville, AL 35805 USA. Georgia Inst Technol, Dept Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Wisconsin, Dept Stat, Madison, WI 53706 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. RP Univ Alabama, NSSTC, Dept Atmospher Sci, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM mike@nsstc.uah.edu; yes@eas.gatech.edu; cunnold@eas.gatech.edu; reinsel@stat.wisc.edu; j.m.zawodny@larc.nasa.gov NR 64 TC 147 Z9 152 U1 1 U2 18 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD AUG 23 PY 2003 VL 108 IS D16 AR 4507 DI 10.1029/2003JD003471 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 715XH UT WOS:000184999200003 ER PT J AU Anderson, JLB Schultz, PH Heineck, JT AF Anderson, JLB Schultz, PH Heineck, JT TI Asymmetry of ejecta flow during oblique impacts using three-dimensional particle image velocimetry SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article DE oblique impacts; ejecta flow; particle image velocimetry; Ames Vertical Gun Range; experimental impacts ID HYPERVELOCITY IMPACT; VELOCITY DISTRIBUTIONS; SAND; PROJECTILE; CHICXULUB; TARGETS AB Three-dimensional particle image velocimetry (3D PIV) applied to impact cratering experiments allows the direct measurement of ejecta particle positions and velocities within the ejecta curtain as the crater grows. Laboratory experiments were performed at the NASA Ames Vertical Gun Range with impact velocities near 1 km/s (6.35-mm diameter aluminum spheres) into a medium-grained (0.5 mm) particulate sand target in a vacuum at 90degrees and 30degrees from the horizontal. This study examines the first 50% of crater growth, during which the crater has grown to one half its final radius. From the 3D PIV data, the ballistic trajectories of the ejecta particles are extrapolated back to the target surface to determine ejection velocities, angles, and positions. For vertical impacts these ejection parameters remain constant in all directions (azimuths) around the crater center. The 30degrees impacts exhibit asymmetries with respect to azimuth that persist well into the excavation-stage flow. These asymmetries indicate that a single stationary point source is not adequate to describe the subsurface flow field during an oblique impact. C1 Brown Univ, Providence, RI 02912 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Anderson, JLB (reprint author), Brown Univ, 324 Brook St, Providence, RI 02912 USA. EM Jennifer_Anderson@brown.edu NR 34 TC 54 Z9 54 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD AUG 23 PY 2003 VL 108 IS E8 AR 5094 DI 10.1029/2003JE002075 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 715XV UT WOS:000185000500001 ER PT J AU Pulkkinen, TI Tanskanen, EI Wiltberger, M Slavin, JA Nagai, T Reeves, GD Frank, LA Sigwarth, JB AF Pulkkinen, TI Tanskanen, EI Wiltberger, M Slavin, JA Nagai, T Reeves, GD Frank, LA Sigwarth, JB TI Magnetotail flows can consume as much solar wind energy as a substorm SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article DE magnetotail; substorm; MHD-simulation; flow bursts ID INTERPLANETARY MAGNETIC-FIELD; PLASMA SHEET; EARTHS MAGNETOSPHERE; POLAR-CAP; GEOMAGNETIC STORMS; MHD SIMULATIONS; CONVECTION; SPACECRAFT; MODEL; TAIL AB We examine an event on 17 December 1997, during which the Wind and ACE spacecraft measured an extended period of southward interplanetary magnetic field. The high values of the epsilon parameter were interpreted as strong energy input into the magnetotail. Despite this energy input, the polar cap potential and area remained constant over a period of several hours, the inner magnetotail was very quiet, and there were no substorm signatures either in the magnetotail or in the ionosphere. Comparison of data and MHD simulation results show that the energy input to the magnetosphere was enhanced and that this event was not a case where the solar wind monitor would have trouble predicting the interplanetary field reaching the Earth orbit. Both Geotail observations in the tail and the MHD simulations show that a substantial amount of energy was being consumed in the tail flow activity during this period. Order of magnitude estimates indicate that the flows indeed were sufficient to consume the incoming energy in a quasi-continuous even if bursty manner. Observations from the IMAGE meridional magnetometer network reveal that the substorm that followed several hours later was relatively small, and its size was proportional to the energy input after the substorm onset, not to the total energy input since the southward turning of the interplanetary field. It is argued that the continuous flow activity disturbed the formation of the thin current sheet in the inner magnetotail, which led to the delay in the substorm development. However, the controlling factor which finally led to the global instability remains an open issue. C1 Finnish Meteorol Inst, FIN-00101 Helsinki, Finland. Dartmouth Coll, Dept Phys & Astron, Hanover, NH 03755 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Tokyo Inst Technol, Dept Earth & Planetary Sci, Tokyo 152, Japan. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. RP Pulkkinen, TI (reprint author), Finnish Meteorol Inst, POB 503, FIN-00101 Helsinki, Finland. RI Wiltberger, Michael/B-8781-2008; Slavin, James/H-3170-2012; Reeves, Geoffrey/E-8101-2011; Pulkkinen, Tuija/D-8403-2012 OI Wiltberger, Michael/0000-0002-4844-3148; Slavin, James/0000-0002-9206-724X; Reeves, Geoffrey/0000-0002-7985-8098; Pulkkinen, Tuija/0000-0002-6317-381X NR 57 TC 3 Z9 3 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 AUG 23 PY 2003 VL 108 IS A8 AR 1326 DI 10.1029/2001JA009132 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 715YA UT WOS:000185001000001 ER PT J AU Bindschadler, RA King, MA Alley, RB Anandakrishnan, S Padman, L AF Bindschadler, RA King, MA Alley, RB Anandakrishnan, S Padman, L TI Tidally controlled stick-slip discharge of a West Antarctic ice stream SO SCIENCE LA English DT Article ID MASS-BALANCE; AMUNDSEN SEA; GLACIER; BENEATH; ALASKA; INLAND; SHEAR; SPOTS; SHELF; SPEED AB A major West Antarctic ice stream discharges by sudden and brief periods of very rapid motion paced by oceanic tidal oscillations of about 1 meter. Acceleration to speeds greater than 1 meter per hour and deceleration back to a stationary state occur in minutes or less. Slip propagates at approximately 88 meters per second, suggestive of a shear wave traveling within the subglacial till. A model of an episodically slipping friction-locked fault reproduces the observed quasi-periodic event timing, demonstrating an ice stream's ability to change speed rapidly and its extreme sensitivity to subglacial conditions and variations in sea level. C1 NASA, Goddard Space Flight Ctr, Ocean & Ice Branch, Greenbelt, MD 20771 USA. Univ Newcastle Upon Tyne, Sch Civil Engn & Geosci, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England. Penn State Univ, Dept Geosci, University Pk, PA 16802 USA. Penn State Univ, EMS Environm Inst, University Pk, PA 16802 USA. Earth & Space Res, Seattle, WA 98102 USA. RP Bindschadler, RA (reprint author), NASA, Goddard Space Flight Ctr, Ocean & Ice Branch, Greenbelt, MD 20771 USA. RI King, Matt/B-4622-2008 OI King, Matt/0000-0001-5611-9498 NR 30 TC 137 Z9 138 U1 1 U2 17 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD AUG 22 PY 2003 VL 301 IS 5636 BP 1087 EP 1089 DI 10.1126/science.1087231 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 713RP UT WOS:000184872400037 PM 12934005 ER PT J AU Ng, HT Chen, B Koehne, JE Cassell, AM Li, J Han, J Meyyappan, M AF Ng, HT Chen, B Koehne, JE Cassell, AM Li, J Han, J Meyyappan, M TI Growth of carbon nanotubes: A combinatorial method to study the effects of catalysts and underlayers SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MULTILAYERED METAL-CATALYSTS AB With their interesting electrical, structural, and physical properties, carbon nanotubes (CNTs) are envisioned to impact future nanoelectronics, nanosensors, and nanophotonics. Current research and development efforts in the growth of CNTs rely on the time-consuming one-parameter-at-a-time approach, whereby marginal variations in growth conditions from run-to-run experiments could result in substantially different outcomes. Here we report a highly efficient combinatorial approach to study the effects of catalysts and underlying metals for the generation of a comprehensive discovery library of CNTs. Shadow masking and sequential ion-beam deposition are used to construct an ensemble of catalysts and underlying metals on a generic addressable platform, whereby upon chemical vapor deposition, the CNT library can be assayed efficiently and conveniently to reveal a host of interesting phenomena. The approach could, in principle, be adapted and used for combinatorial investigations of other nanostructures. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. ELORET Corp, Sunnyvale, CA 94087 USA. RP Ng, HT (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RI Li, Jun/H-7771-2013 OI Li, Jun/0000-0002-3689-8946 NR 17 TC 70 Z9 70 U1 2 U2 12 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 AUG 21 PY 2003 VL 107 IS 33 BP 8484 EP 8489 DI 10.1021/jp034198w PG 6 WC Chemistry, Physical SC Chemistry GA 713KB UT WOS:000184855700035 ER EF