FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Eriksen, HK Banday, AJ Gorski, KM Lilje, PB AF Eriksen, HK Banday, AJ Gorski, KM Lilje, PB TI The N-point correlation functions of the first-year Wilkinson Microwave Anisotropy Probe sky maps SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : observations; methods : statistical ID ANGULAR POWER SPECTRUM; WMAP OBSERVATIONS; NON-GAUSSIANITY; EMISSION; ASYMMETRIES AB We compute the two-, three- and four-point correlation functions from the Wilkinson Microwave Anisotropy Probe (WMAP) first-year data and compare these with a Monte Carlo ensemble of 5000 realizations based on the best-fit WMAP running-index spectrum of Gaussian fluctuations. The analysis is carried out in three steps, covering small (<72'), intermediate (<5 degrees), and large scales (up to 180 degrees). On the largest scales our results are consistent with the previously reported hemisphere power asymmetries: the northern ecliptic hemisphere is practically devoid of large-scale fluctuations, while the southern hemisphere shows relatively strong fluctuations. We also detect excess correlations in W-band difference maps as compared with the detailed noise simulations produced by the WMAP team, possibly indicative of unknown systematics. While unlikely to affect any temperature-based results, this effect could potentially be important for the upcoming polarization data. On intermediate angular scales we find hints of a similar anisotropic distribution of power as seen on the very largest scales, but not to the same extent. In general, the model is accepted on these scales. Finally, the same is also true on the smallest scales probed in this paper. C1 Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Max Planck Inst Astrophys, D-85741 Garching, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Warsaw Observ, PL-00478 Warsaw, Poland. Univ Oslo, Inst Theoret Astrophys, N-0315 Oslo, Norway. Univ Oslo, Ctr Math Appl, N-0316 Oslo, Norway. RP Eriksen, HK (reprint author), Univ Oslo, Inst Theoret Astrophys, POB 1029, N-0315 Oslo, Norway. EM h.k.k.eriksen@astro.uio.no; banday@mpa-garching.mpg.de; krzysztof.m.gorski@jpl.nasa.gov; per.lilje@astro.uio.no RI Lilje, Per/A-2699-2012; OI Lilje, Per/0000-0003-4324-7794 NR 30 TC 71 Z9 71 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 2005 VL 622 IS 1 BP 58 EP 71 DI 10.1086/427897 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TM UT WOS:000227740900005 ER PT J AU Mitchell, JL Keeton, CR Frieman, JA Sheth, RK AF Mitchell, JL Keeton, CR Frieman, JA Sheth, RK TI Improved cosmological constraints from gravitational lens statistics SO ASTROPHYSICAL JOURNAL LA English DT Review DE cosmological parameters; cosmology : observations; cosmology : theory; gravitational lensing ID EARLY-TYPE GALAXIES; ALL-SKY SURVEY; DARK-MATTER HALOES; HUBBLE-SPACE-TELESCOPE; VLA ASTROMETRIC SURVEY; LUMINOSITY FUNCTION; ELLIPTIC GALAXIES; REDSHIFT SURVEY; RADIO-SOURCES; EXTRAGALACTIC SURVEYS AB We combine the Cosmic Lens All-Sky Survey (CLASS) with new Sloan Digital Sky Survey (SDSS) data on the local velocity dispersion distribution function of E/S0 galaxies, phi(sigma), to derive lens statistics constraints on Omega(Lambda) and Omega(m). Previous studies of this kind relied on a combination of the E/S0 galaxy luminosity function and the Faber-Jackson relation to characterize the lens galaxy population. However, ignoring dispersion in the Faber-Jackson relation leads to a biased estimate of phi(sigma) and therefore biased and overconfident constraints on the cosmological parameters. The measured velocity dispersion function from a large sample of E/S0 galaxies provides a more reliable method for probing cosmology with strong lens statistics. Our new constraints are in good agreement with recent results from the redshift-magnitude relation of Type Ia supernovae. Adopting the traditional assumption that the E/S0 velocity function is constant in comoving units, we find a maximum likelihood estimate of Omega(Lambda) = 0.74- 0: 78 for a spatially flat universe (where the range reflects uncertainty in the number of E/S0 lenses in the CLASS sample) and a 95% confidence upper bound of Omega(Lambda) < 0.86. If phi(sigma) instead evolves in accord with the extended Press-Schechter theory, then the maximum likelihood estimate for Omega(Lambda) becomes 0.72-0.78, with the 95% confidence upper bound Omega(Lambda) < 0.89. Even without assuming flatness, lensing provides independent confirmation of the evidence from Type Ia supernovae for a nonzero dark energy component in the universe. C1 Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Chicago, Ctr Cosmol Phys, Chicago, IL 60637 USA. Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. RP Mitchell, JL (reprint author), Univ Chicago, Dept Astron & Astrophys, 5640 S Ellis Ave, Chicago, IL 60637 USA. NR 113 TC 86 Z9 86 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 MAR 20 PY 2005 VL 622 IS 1 BP 81 EP 98 DI 10.1086/427910 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TM UT WOS:000227740900007 ER PT J AU Piner, BG Edwards, PG AF Piner, BG Edwards, PG TI VLBA polarization observations of Markarian 421 after a gamma-ray high state SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : individual (Markarian 421); galaxies : active; galaxies : jets; radio continuum : galaxies ID ACTIVE GALACTIC NUCLEI; LINE ARRAY OBSERVATIONS; SCALE ROTATION MEASURES; EGRET-DETECTED QUASARS; BL LACERTAE OBJECTS; SIMULTANEOUS X-RAY; TEV BLAZARS; GALAXY MARKARIAN-421; INTERNAL SHOCKS; BRIGHT BLAZARS AB We present four high dynamic range, dual-circular polarization, Very Long Baseline Array (VLBA) observations at 22 GHz of Mrk 421, taken throughout the year following the source's unprecedented gamma-ray high state in early 2001. Previous VLBI observations of this source had shown only subluminal apparent motions in the parsec-scale jet and no apparent connection between jet components and gamma-ray flares, so we examined whether the larger gamma-ray flares of 2001 had produced a component that could be followed on the parsec-scale VLBA images. These four new VLBA observations are combined with data from our earlier 1999 paper and archival VLBA data sets that have become available since 1999 to produce a combined 28 epoch VLBA data set on Mrk 421 spanning 1994-2002. No new component associated with the 2001 flares was seen on the total intensity images, but the combined data set allowed precise measurements of the apparent speeds of the existing components. The peak measured apparent speed was for component C5, which has an apparent speed of 0.1c +/- 0.02c (H-0 = 71 km s(-1) Mpc(-1), Omega(m) = 0.27, and Omega(Lambda) = 0.73). No counterjet is seen with a limit on the jet to counterjet brightness ratio J > similar to 100. These observed VLBI properties of Mrk 421 are consistent with a jet with a bulk Lorentz factor Gamma similar to 2 and an angle to the line of sight theta similar to 1 degrees, suggesting a jet that decelerates between the gamma-ray producing region and the parsec scale. Although a limb-brightened structure is seen in some transverse slices across the jet, it is not seen consistently, inhibiting interpretation in terms of the fast-spine/slow-layer model that has been invoked for other sources. The VLBI core and inner jet (component C7) have fractional polarizations of similar to 5% and an electric vector position angle (EVPA) aligned with the jet axis. Component C5 (at 1.5 mas from the core) has a higher fractional polarization of similar to 15% and an EVPA nearly orthogonal to the jet axis. Significant variability is detected in the EVPA of component C6, which at two of the four epochs shows an EVPA aligned with the jet axis, possibly a sign of propagating disturbances that are only visible on the polarization images. If these propagating disturbances are linked to the 2001 gamma-ray high state, then their inferred apparent speed is between 1c and 3c. C1 Whittier Coll, Dept Phys & Astron, Whittier, CA 90608 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Japan Aerosp Explorat Agcy Yoshinodai, Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. RP Piner, BG (reprint author), Whittier Coll, Dept Phys & Astron, 13406 E Philadelphia St, Whittier, CA 90608 USA. EM gpiner@whittier.edu; pge@vsop.isas.jaxa.jp NR 42 TC 33 Z9 33 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 2005 VL 622 IS 1 BP 168 EP 177 DI 10.1086/428039 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TM UT WOS:000227740900015 ER PT J AU Temi, P Mathews, WG Brighenti, F AF Temi, P Mathews, WG Brighenti, F TI The ages of elliptical galaxies from mid-infrared emission SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : elliptical and lenticular, cD; galaxies : ISM; infrared : galaxies; infrared : ISM ID HUBBLE-SPACE-TELESCOPE; NEUTRAL-HYDROGEN OBSERVATIONS; KINEMATICALLY DISTINCT CORES; ACTIVE GALACTIC NUCLEI; CCD SURFACE PHOTOMETRY; DWARF SEYFERT NUCLEI; NGC-1316 FORNAX-A; STELLAR POPULATIONS; INTERMEDIATE-AGE; INTERSTELLAR MATTER AB The mid-infrared (10-20 mu m) luminosity of elliptical galaxies is dominated by the integrated emission from circumstellar dust in red giant stars. As a single stellar population evolves, the rate of dustymass loss from red giant stars decreases with time, so the mid-infrared luminosity should also decline with stellar age. To seek such a correlation, we have used archival Infrared Space Observatory (ISO) observations to determine surface brightness profiles and central fluxes at 15 mu m in 17 early-type galaxies for which stellar ages have been determined from optical spectral indices. The radial surface brightness distributions at 15 mu m generally follow the stellar de Vaucouleurs profile, as expected. We find that the surface brightness ratio mu(15 mu m)/mu(I band) is systematically higher in elliptical galaxies with ages less than or similar to 5 Gyr and in galaxies that exhibit evidence of recent mergers. Within the accuracy of our observations, mu(15 mu m)/mu(I band) shows no age dependence for ages greater than or similar to 5 Gyr. The corresponding flux ratios F-15 mu m/F-I band within apertures scaled to the effective radius (R-e/8) are proportional to the mu(15 mu m)/mu(I band) ratios at larger galactic radii, indicating that no 15 mu m emission is detected from central dust clouds visible in optical images in some of our sample galaxies. Emission at 15 mu m is observed in noncentral massive clouds of dust and cold gas in NGC1316, an elliptical galaxy that is thought to have had a recent merger. Recent Spitzer Space Telescope data also indicate the presence of polycyclic aromatic hydrocarbon (PAH) emission at 8 mu m. Several ellipticals have extended regions of 15 mu m emission that have no obvious counterparts at other frequencies. C1 NASA, Ames Res Ctr, Astrophys Branch, Moffett Field, CA 94035 USA. SETI Inst, Mountain View, CA 94043 USA. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Board Studies Astron & Astrophys, Santa Cruz, CA 95064 USA. Univ Bologna, Dipartimento Astron, I-40127 Bologna, Italy. RP Temi, P (reprint author), NASA, Ames Res Ctr, Astrophys Branch, MS 245-6, Moffett Field, CA 94035 USA. NR 74 TC 27 Z9 28 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 MAR 20 PY 2005 VL 622 IS 1 BP 235 EP 243 DI 10.1086/427867 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TM UT WOS:000227740900020 ER PT J AU Cotera, AS Colgan, SWJ Simpson, JP Rubin, RH AF Cotera, AS Colgan, SWJ Simpson, JP Rubin, RH TI The interaction of the Galactic center arches cluster and the thermal filaments SO ASTROPHYSICAL JOURNAL LA English DT Article DE Galaxy : center; infrared : ISM; open clusters and associations : individual (Arches) ID ELEMENTAL ABUNDANCE RATIOS; FINE-STRUCTURE LINES; H-II REGIONS; PHOTODISSOCIATION REGIONS; RADIO ARC; MASSIVE STARS; WAVELENGTH SPECTROMETER; HII-REGIONS; HOT STARS; EMISSION AB We present Infrared Space Observatory (ISO) measurements of the far-infrared (FIR) fine-structure lines [S IV] (10.5 mu m), [S III] (33.5 mu m), [O III] (51.8 and 88.4 mu m), [N III] (57.3 mu m), [N II] (121.9 mu m), [O I] (63.2 and 145.5 mu m), and [C II] (157.7 mu m) at five positions on the thermal "Arched'' Filaments in the Galactic center region in order to investigate the influence of the massive, young Arches cluster on the interstellar medium. Serendipitous measurements of OH (119.3 mu m) are also presented. Radio recombination line and ISO spectroscopic measurements provide strong evidence that the Arches cluster is responsible for the excitation of the Arched Filaments. The observations reported here were selected to provide measurements close to the Arches cluster and at uniformly increasing projected distances over the range 0-9 pc. Within the measurement uncertainties, the diagnostic line ratios most sensitive to excitation and least sensitive to density fluctuations, [O III]/[S III] and [S IV]/[S III], appear to decrease with projected distance from the Arches cluster. In agreement with other studies, this provides additional evidence that the cluster is the primary ionization source for the Arched Filaments. The total FIR luminosity also generally falls with projected distance from the Arches cluster. The best predictions from photoionization models for the rapid decrease in the measured line flux ratios with projected distance from the Arches cluster, however, are only accurate to a factor of 1.5, including allowance for additional offset along the line of sight. The measurements of lines formed predominantly in photodissociation regions are not well matched by current models. High-resolution spectra indicate gas moving at -70 km s(-1) only at the location of the Arches cluster, significantly different from the predominant -30 km s(-1) gas seen in the underlying molecular cloud. C1 SETI Inst, Mountain View, CA 94043 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Orion Enterprises, Moffett Field, CA USA. RP Cotera, AS (reprint author), SETI Inst, 2035 Landings Dr, Mountain View, CA 94043 USA. EM acotera@seti.org; sean.colgan@nasa.gov; simpson@cygnus.arc.nasa.gov; rubin@cygnus.arc.nasa.gov RI Colgan, Sean/M-4742-2014 NR 45 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 MAR 20 PY 2005 VL 622 IS 1 BP 333 EP 345 DI 10.1086/427794 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TM UT WOS:000227740900027 ER PT J AU Oegerle, WR Jenkins, EB Shelton, RL Bowen, DV Chayer, P AF Oegerle, WR Jenkins, EB Shelton, RL Bowen, DV Chayer, P TI A survey of OVI absorption in the local interstellar medium SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : general; ultraviolet : ISM ID DA WHITE-DWARFS; EXTREME-ULTRAVIOLET EXPLORER; O-VI ABSORPTION; SUPERNOVA-REMNANTS; FUSE OBSERVATIONS; 3-DIMENSIONAL STRUCTURE; SPATIAL VARIATIONS; DIFFUSE MEDIA; CORONAL GAS; HOT GAS AB We report the results of a survey of O VI lambda 1032 absorption along the lines of sight to 25 white dwarfs in the local interstellar medium (LISM) obtained with FUSE. We find that interstellar O VI absorption along all sight lines is generally weak, and in a number of cases, completely absent. No O VI absorption was detected with significance greater than 2 sigma for 12 of the 25 stars, where the 1 sigma uncertainty is similar to 4 m angstrom, equivalent to an O VI column density of similar to 3x10(12) cm(-2). Of the remaining stars, most have column densities N(O VI)<10(13) cm(-2), and no column densities exceed 1.7x10(13) cm(-2). For lines of sight to hot (T-eff>40,000 K) white dwarfs, there is some evidence that the O VI absorption may be at least partially photospheric or circumstellar in origin. We interpret the "patchy'' distribution of O VI absorption in terms of a model in which O VI is formed in evaporative interfaces between cool clouds and the hot, diffuse gas in the Local Bubble (LB). If the clouds contain tangled or tangential magnetic fields, then thermal conduction will be quenched over most of the cloud surface, and O VI will be formed only in local "patches'' where conduction is allowed to operate. We find an average O VI space density in the LISM of 2.4x10(-8) cm(-3), which is similar to, or slightly larger than, the value in the Galactic disk over kiloparsec scales. This local density implies an average O VI column density of similar to 7x10(12) cm(-2) over a path length of 100 pc within the LB. The O VI data presented here appear to be inconsistent with the model proposed by Breitschwerdt W Schmutzler, in which highly ionized gas at low kinetic temperature (similar to 50,000 K) permeates the LB. Our survey results are consistent with the supernova-driven cavity picture of Cox W Smith for the LB, and in particular, the recent model by Cox W Helenius for the creation of cool clouds in the LB by magnetic flux tubes and their subsequent magnetic shielding from conduction. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Univ Georgia, Dept Phys & Astron, Athens, GA 30602 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Victoria, Dept Phys & Astron, Victoria, BC V8W 3P6, Canada. RP Oegerle, WR (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 681, Greenbelt, MD 20771 USA. RI Oegerle, William/C-9070-2012; Jenkins, Edward/P-5684-2014 OI Jenkins, Edward/0000-0003-1892-4423 NR 73 TC 72 Z9 72 U1 0 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 2005 VL 622 IS 1 BP 377 EP 389 DI 10.1086/427792 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TM UT WOS:000227740900030 ER PT J AU Harker, DE Woodward, CE Wooden, DH Temi, P AF Harker, DE Woodward, CE Wooden, DH Temi, P TI The disk atmospheres of three Herbig Ae/Be stars SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : general ID COMET HALE-BOPP; INTERSTELLAR SILICATE MINERALOGY; SPECTRAL ENERGY-DISTRIBUTIONS; INTERMEDIATE-MASS STARS; CRYSTALLINE SILICATES; CIRCUMSTELLAR DISKS; T-TAURI; SOLAR NEBULA; HIGH-RESOLUTION; AE SYSTEMS AB We present infrared (IR) spectrophotometry (R similar or equal to 180) of three Herbig Ae/Be stars surrounded by possible protoplanetary disks: HD 150193, HD 100546, and HD 179218. We construct a mid-IR spectral energy distributions (SEDs) for each object by using 7.6-13.2 mu m HIFOGS spectra, 2.4-45 mu m spectrophotometry from the Infrared Space Observatory Short-Wavelength Spectrometer, the 12, 25, 60, and 100 mu m photometric points from IRAS, and for HD 179218, photometric bolometric data points from the Mount Lemmon Observing Facility. The SEDs are modeled by using an expanded version of the Chiang W Goldreich two-layer, radiative and hydrostatic equilibrium, passive disk. This expanded version includes the emission from Mg-pure crystalline olivine (forsterite) grains in the disk surface layer. Each of the three objects studied vary in the amount of crystals evident from their spectrophotometry. HD 150193 contains no crystals, while HD 100546 and HD 179218, respectively, show evidence of having crystalline silicates in the surface layers of their disks. We find that the inner region of HD 100546 has a 37% higher crystalline-to-amorphous silicate ratio in its inner disk region (<= 5 AU) than in the outer disk region, while the inner disk region of HD 179218 has a 84% higher crystalline-to-amorphous silicate ratio in its inner disk region (<= 5 AU) than in the outer region. All three objects are best fitted using a grain-size distribution power law that falls as a(-3.5). HD 150193 is best fitted by a small disk (similar to 5 AU in radius), while HD 100546 and HD 179218 are best fitted by larger disks (similar to 150 AU in radius). Furthermore, HD 100546's disk flares larger than those of HD 150193 (25% more at 5 AU) and HD 179218 (80% more at 5 AU). We discuss the implications of our results and compare them with other modeling efforts. C1 Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. Univ Minnesota, Sch Phys & Astron, Dept Astron, Minneapolis, MN 55455 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Harker, DE (reprint author), Univ Calif San Diego, Ctr Astrophys & Space Sci, 9500 Gilman Dr, La Jolla, CA 92093 USA. OI Harker, David/0000-0001-6397-9082 NR 51 TC 3 Z9 3 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 MAR 20 PY 2005 VL 622 IS 1 BP 430 EP 439 DI 10.1086/427968 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TM UT WOS:000227740900034 ER PT J AU Ling, JC Wheaton, WA AF Ling, JC Wheaton, WA TI Gamma-ray spectral state transitions of GRO J1719-24 SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; gamma rays : observations ID NOVA-OPHIUCHI 1993; CYGNUS X-1; BLACK-HOLES; VARIABILITY; BATSE; ACCRETION; NOVA-OPHIUCHI-1993; COMPTONIZATION; RADIO; FLOWS AB We report the results of an in-depth study of the long-term soft gamma-ray (30 keV to 1.7 MeV) flux and spectral variability of the transient source GRO J1719-24 that was first discovered by BATSE and SIGMA in the fall of 1993. Our results were obtained from the JPL BATSE-EBOP database covering a 1000 day period between 1993 January 13 and 1995 October 10. During this period, the source underwent a major outburst in the fall of 1993 when the 35-100 keV flux rose from a quiescent state of less than 16 mcrab before 1993 September 17 to a level of 1.5 crab on October 3. The source remained in this high-intensity state over the next similar to 70 days, during which the 35 100 keV flux decreased monotonically by similar to 33% to similar to 1 crab on December 12, then decreased sharply to the pre-transition quiescent level of similar to 44 mcrab on December 21, where it remained until 1994 September 5. During a 400 day period between 1994 September 5 and 1995 October 10, the source again underwent a series of five transitions when the 35-100 keV flux increased to low-intensity levels of similar to 200-400 mcrab, a factor of 4-7 times lower than what was observed in 1993. The low- and high-intensity states were characterized by two different spectral shapes. The low- state spectra are described by a power law with a spectral index of similar to 2. The high-state spectra, on the other hand, have two components: a thermal Comptonized shape below similar to 200 keV with electron temperature kT(e) of similar to 37 keV and optical depth tau similar to 2.8, and a soft power-law tail with photon index of similar to 3.4 above 200 keV that extends to similar to 500 keV. The softer high-intensity spectrum and the harder low- intensity spectrum intersect at similar to 400 keV. The nonthermal power-law gamma-ray component in both the high- and low-intensity spectra suggests that the persistent nonthermal emission source is coupled to the hot and variable thermal emission source in the system. Furthermore, the correlation of the spectral characteristics with the high- and low- intensity states resembles that seen in two other gamma-ray-emitting black hole candidates, GRO J0422+32 and Cygnus X-1, suggesting that perhaps similar system configurations and processes are occurring in these systems. Possible scenarios for interpreting these behaviors are discussed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. RP Ling, JC (reprint author), CALTECH, Jet Prop Lab, MS 169-327,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM james.c.ling@jpl.nasa.gov; waw@ipac.caltech.edu NR 32 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 MAR 20 PY 2005 VL 622 IS 1 BP 492 EP 502 DI 10.1086/428081 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TM UT WOS:000227740900039 ER PT J AU Harding, AK Usov, VV Muslimov, AG AF Harding, AK Usov, VV Muslimov, AG TI High-energy emission from millisecond pulsars SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : theory; pulsars : general; radiation mechanisms : nonthermal; stars : neutron ID GAMMA-RAY PULSARS; RADIATION PAIR FRONTS; X-RAY; SYNCHROTRON ABSORPTION; COMPTON-SCATTERING; MAGNETIC-FIELDS; CRAB-NEBULA; MAGNETOSPHERES; ELECTRONS; SPECTRA AB The X-ray and gamma-ray spectrum of rotation-powered millisecond pulsars is investigated in a model for acceleration and pair cascades on open field lines above the polar caps. Although these pulsars have low surface magnetic fields, their short periods allow them to have large magnetospheric potential drops, but the majority do not produce sufficient pairs to completely screen the accelerating electric field. In these sources, the primary and secondary electrons continue to accelerate to high altitude, and their Lorentz factors are limited by curvature and synchrotron radiation reaction. The accelerating particles maintain high Lorentz factors and undergo cyclotron resonant absorption of radio emission that produces and maintains a large pitch angle, resulting in a strong synchrotron component. The resulting spectra consist of several distinct components: curvature radiation from primary electrons dominating from 1 to 100 GeV, synchrotron radiation from primary and secondary electrons dominating up to about 100 MeV, and much weaker inverse Compton radiation from primary electrons at 0.1-1 TeV. We find that the relative size of these components depends on pulsar period, period derivative, and neutron star mass and radius, with the level of the synchrotron component also depending sensitively on the radio emission properties. This model is successful in describing the observed X-ray and gamma-ray spectrum of PSR J0218+4232 as synchrotron radiation, peaking around 100 MeV and extending up to a turnover around several GeV. The predicted curvature radiation components from a number of millisecond pulsars, as well as the collective emission from the millisecond pulsars in globular clusters, should be detectable with AGILE and GLAST. We also discuss a hidden population of X-ray-quiet and radio-quiet millisecond pulsars that have evolved below the pair death line, some of which may be detectable by telescopes sensitive above 1 GeV. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Weizmann Inst Sci, IL-76100 Rehovot, Israel. RP Harding, AK (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RI Harding, Alice/D-3160-2012 NR 42 TC 96 Z9 96 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 MAR 20 PY 2005 VL 622 IS 1 BP 531 EP 543 DI 10.1086/427840 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TM UT WOS:000227740900043 ER PT J AU Mukai, K Orio, M AF Mukai, K Orio, M TI X-ray observations of the bright old Nova V603 Aquilae SO ASTROPHYSICAL JOURNAL LA English DT Article DE novae, cataclysmic variables; stars : individual (V603 Aquilae); X-rays : binaries ID NONMAGNETIC CATACLYSMIC VARIABLES; TRANSMISSION GRATING SPECTROMETER; ACCRETION DISKS; CLASSICAL NOVAE; GALACTIC RIDGE; V603 AQUILAE; WHITE-DWARF; LIGHT-CURVE; SS-CYGNI; EMISSION AB We report on our Chandra and Rossi X-Ray Timing Explorer (RXTE) observations of the bright old nova V603 Aq1 performed in 2001 April and supplement it with our analysis of archival X-ray data on this object. We find that the RXTE data are contaminated by the Galactic ridge X-ray emission. After accounting for this effect, we find a high level of aperiodic variability in the RXTE data, at a level consistent with the uncontaminated Chandra data. The Chandra High Energy Transmission Grating spectrum clearly originates in a multitemperature plasma. We constrain the possible emission measure distribution of the plasma through a combination of global and local fits. The X-ray luminosity and the spectral shape of V603 Aq1 resemble those of SS Cyg when it is in transition between quiescence and outburst. The fact that the X-ray flux variability is only weakly energy dependent can be interpreted by supposing that the variability is due to changes in the maximum temperature of the plasma. The plasma density is likely to be high, and the emission region is likely to be compact. Finally, the apparent overabundance of Ne is consistent with V603 Aq1 being a young system. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Osserv Astron Torino, INAF, I-10025 Pino Torinese, Italy. Univ Space Res Assoc, Columbia, MD 21044 USA. Univ Wisconsin, Dept Astron, Madison, WI 53706 USA. RP Mukai, K (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 662, Greenbelt, MD 20771 USA. NR 57 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 MAR 20 PY 2005 VL 622 IS 1 BP 602 EP 612 DI 10.1086/427915 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TM UT WOS:000227740900051 ER PT J AU Liu, C Deng, N Liu, Y Falconer, D Goode, PR Denker, C Wang, HM AF Liu, C Deng, N Liu, Y Falconer, D Goode, PR Denker, C Wang, HM TI Rapid change of delta spot structure associated with seven major flares SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : activity; Sun : corona; Sun : flares; Sun : magnetic fields; sunspots ID X-CLASS FLARES; MICHELSON DOPPLER IMAGER; MAGNETIC-FIELD EVOLUTION; SOLAR-FLARES; TRANSITION REGION; CORONAL EXPLORER; NESTED SUNSPOTS; FLUX EMERGENCE; JULY 14; MODEL AB A large fraction of major flares occur in active regions that exhibit a delta configuration. The formation and disintegration of delta configurations is very important in understanding the evolution of photospheric magnetic fields. In this paper we study the relationship between the change in delta spot structures and associated major flares. We present a new observational result that part of penumbral segments in the outer delta spot structure decay rapidly after major flares; meanwhile, the neighboring umbral cores and/or inner penumbral regions become darker. Using white-light (WL) observations from the Transition Region and Coronal Explorer ( TRACE), we study the short-term evolution of delta spots associated with seven major flares, including six X-class flares and one M-class flare. The rapid changes, which can be identified in the time profiles of WL mean intensity are permanent, not transient, and thus are not due to flare emission. The co-aligned magnetic field observations obtained with the Michelson Doppler Imager (MDI) show substantial changes in the longitudinal magnetic field associated with the decaying penumbrae and darkened central areas. For two events for which vector magnetograms were available, we find that the transverse field associated with the penumbral decay areas decreased while it increased in the central darkened regions. Both events also show an increase in the magnetic shear after the flares. For all the events, we find that the locations of penumbral decay are related to flare emission and are connected by prominent TRACE postflare loops. To explain these observations, we propose a reconnection picture in which the two components of a delta spot become strongly connected after the flare. The penumbral fields change from a highly inclined to a more vertical configuration, which leads to penumbral decay. The umbral core and inner penumbral region become darker as a result of increasing longitudinal and transverse magnetic field components. C1 New Jersey Inst Technol, Ctr Solar Terr Res, Newark, NJ 07102 USA. Kyoto Univ, Kwasan Observ, Yamashina Ku, Kyoto 6078471, Japan. Kyoto Univ, Hida Observ, Yamashina Ku, Kyoto 6078471, Japan. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Liu, C (reprint author), New Jersey Inst Technol, Ctr Solar Terr Res, Univ Hts, Newark, NJ 07102 USA. EM cl45@njit.edu RI Liu, Yu/B-4833-2009; OI Liu, Yu/0000-0002-7694-2454; Liu, Chang/0000-0002-6178-7471 NR 53 TC 87 Z9 87 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 MAR 20 PY 2005 VL 622 IS 1 BP 722 EP 736 DI 10.1086/427868 PN 1 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TM UT WOS:000227740900060 ER PT J AU Galloway, DK Markwardt, CB Morgan, EH Chakrabarty, D Strohmayer, TE AF Galloway, DK Markwardt, CB Morgan, EH Chakrabarty, D Strohmayer, TE TI Discovery of the accretion-powered millisecond X-ray pulsar IGR J00291+5934 SO ASTROPHYSICAL JOURNAL LA English DT Article DE binaries : close; pulsars : individual (IGR J00291+5934); stars : low-mass, brown dwarfs; stars : neutron; X-rays : binaries ID SAX J1808.4-3658; NEUTRON-STARS; BINARY; ORBIT AB We report on observations of the sixth accretion-powered millisecond pulsar, IGR J00291 + 5934, with the Rossi X-Ray Timing Explorer. The source is a faint recurrent X-ray transient initially identified by the International Gamma-Ray Astrophysics Laboratory. The 599 Hz (1.67 ms) pulsation had a fractional rms amplitude of 8% in the 2-20 keV range, and its shape was approximately sinusoidal. The pulses show an energy-dependent phase delay, with the 6-9 keV pulses arriving up to 85 ms earlier than those at lower energies. No X-ray bursts, dips, or eclipses were detected. The neutron star is in a circular 2.46 hr orbit with a very low-mass donor, most likely a brown dwarf. The binary parameters of the system are similar to those of the first known accreting millisecond pulsar, SAX J1808.4 - 3658. Assuming that the mass transfer is driven by gravitational radiation and that the 2004 outburst fluence is typical, the 3 yr recurrence time implies a distance of at least 4 kpc. C1 MIT, Ctr Space Res, Cambridge, MA 02139 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. RP Galloway, DK (reprint author), MIT, Ctr Space Res, Cambridge, MA 02139 USA. EM duncan@space.mit.edu OI Galloway, Duncan/0000-0002-6558-5121 NR 39 TC 77 Z9 77 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 2005 VL 622 IS 1 BP L45 EP L48 DI 10.1086/429563 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TR UT WOS:000227741400012 ER PT J AU Sahai, R Le Mignant, D Contreras, CS Campbell, RD Chaffee, FH AF Sahai, R Le Mignant, D Contreras, CS Campbell, RD Chaffee, FH TI Sculpting a pre-planetary nebula with a precessing jet: IRAS 16342-3814 SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; ISM : jets and outflows; planetary nebulae : general; stars : AGB and post-AGB; stars : individual (IRAS 16342-3814); stars : mass loss ID PLANETARY-NEBULAE; MASS-LOSS; PROTOPLANETARY NEBULAE; IRAS 16342-3814; GIANT BRANCH; STAR; OH-231.8+4.2; TELESCOPE; HISTORY; SYSTEM AB We have imaged the bipolar pre-planetary nebula IRAS 16342-3814 with the Keck adaptive optics (AO) system in four near-infrared bands in the 1.6-4.7 mu m range. The lobes, which showed smoothly varying brightness distributions in previous optical images taken with the Hubble Space Telescope, have a limb-brightened appearance in the AO images, with a remarkable corkscrew structure inscribed on the lobe walls. A well-collimated, precessing jet with a diameter less than or similar to 100 AU and a precession period less than or similar to 50 yr, interacting with ambient circumstellar material, is most likely responsible for the corkscrew structure and the lobes, as indicated by a detailed comparison of our observations with published numerical simulations. The very red colors of the lobes in the near-infrared, coupled with their visibility at optical wavelengths, require that at least half, but not all, of the light of the central star be trapped by a compact circumstellar dust cloud heated to similar to 600-700 K and reradiated in the infrared. The lobes are thus illuminated both by the infrared light from this dust cloud as well as by the optical light from the central star. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. WM Keck Observ, Kamuela, HI 96743 USA. CALTECH, Pasadena, CA 91125 USA. RP Sahai, R (reprint author), CALTECH, Jet Prop Lab, MS 183-900, Pasadena, CA 91109 USA. EM raghvendra.sahai@jpl.nasa.gov RI Sanchez-Contreras, Carmen/N-3718-2015 OI Sanchez-Contreras, Carmen/0000-0002-6341-592X NR 25 TC 22 Z9 22 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 20 PY 2005 VL 622 IS 1 BP L53 EP L56 DI 10.1086/429586 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TR UT WOS:000227741400014 ER PT J AU Stiavelli, M Djorgovski, SG Pavlovsky, C Scarlata, C Stern, D Mahabal, A Thompson, D Dickinson, M Panagia, N Meylan, G AF Stiavelli, M Djorgovski, SG Pavlovsky, C Scarlata, C Stern, D Mahabal, A Thompson, D Dickinson, M Panagia, N Meylan, G TI Evidence of primordial clustering around the QSO SDSS J1030+0524 at z=6.281 SO ASTROPHYSICAL JOURNAL LA English DT Article DE early universe; galaxies : formation; galaxies : high-redshift ID LARGE-SCALE STRUCTURES; LYMAN-BREAK GALAXIES; ORIGINS DEEP SURVEY; HIGH-REDSHIFT; REIONIZATION; UNIVERSE; DISCOVERY; DENSITY; QUASAR; SPACE AB We present tentative evidence of primordial clustering, manifested as an excess of color-selected objects in the field of the QSO SDSS J1030 + 0524 at redshift z = 6.28. We have selected objects red in i(775) - z(850) on the basis of Hubble Space Telescope Advanced Camera for Surveys imaging of a field centered on the QSO. Compared to data at comparable depth obtained by the Great Observatories Origins Deep Survey, we find an excess of objects with i (775) - z(850) >= 1.5 in the QSO field. The significance of the detection is estimated to be similar to 97% on the basis of the counts alone and increases to 99.4% if one takes into account the color distribution. If confirmed, this would represent the highest redshift example of galaxy clustering and would have implications on models for the growth of structure. Bias-driven clustering of first luminous objects forming in the highest peaks of the primordial density field is expected in most models of early structure formation. The redshift of one of the candidates has been found to be z = 5.970 by our spectroscopy with the Keck I Low Resolution Imaging Spectrometer, confirming the validity of our color selection. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. ESA, Space Telescope Div, Baltimore, MD 21218 USA. Observ, Ecole Polytech Fed Lausanne, Astrophys Lab, CH-1290 Chavannes Des Bois, Switzerland. RP Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. EM mstiavel@stsci.edu; george@astro.caltech.edu; cherylp@stsci.edu; scarlata@phys.ethz.ch; stern@thisvi.jpl.nasa.gov; aam@astro.caltech.edu; djt@irastro.caltech.edu; med@noao.edu; panagia@stsci.edu; georges.meylan@epfl.ch NR 40 TC 48 Z9 48 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 MAR 20 PY 2005 VL 622 IS 1 BP L1 EP L4 DI 10.1086/429406 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 907TR UT WOS:000227741400001 ER PT J AU Bijl, H Carpenter, MH AF Bijl, H Carpenter, MH TI Iterative solution techniques for unsteady flow computations using higher order time integration schemes SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS LA English DT Article; Proceedings Paper CT 8th ICFD Conference on Numerical Methods for Fluid Dynamics CY 2004 CL Oxford Univ Comp Lab, Oxford, ENGLAND SP Inst Computat Fluid Dynam HO Oxford Univ Comp Lab DE unsteady flows; implicit time integration methods; iterative solvers ID NAVIER-STOKES EQUATIONS AB In this paper iterative techniques for unsteady flow computations with implicit higher order time integration methods at large time steps are investigated. It is shown that with a minimal coding effort the standard non-linear multigrid method can be combined with a Newton-Krylov method leading to speed-ups in the order of 30%. Copyright (c) 2005 John Wiley I Sons, Ltd. C1 Delft Univ Technol, Fac Aerosp Engn, NL-2629 HS Delft, Netherlands. NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23665 USA. RP Bijl, H (reprint author), Delft Univ Technol, Fac Aerosp Engn, Kluyverweg 1, NL-2629 HS Delft, Netherlands. EM h.bijl@lr.tudelft.nl NR 9 TC 10 Z9 10 U1 0 U2 3 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 0271-2091 J9 INT J NUMER METH FL JI Int. J. Numer. Methods Fluids PD MAR 20 PY 2005 VL 47 IS 8-9 BP 857 EP 862 DI 10.1002/fld.861 PG 6 WC Computer Science, Interdisciplinary Applications; Mathematics, Interdisciplinary Applications; Mechanics; Physics, Fluids & Plasmas SC Computer Science; Mathematics; Mechanics; Physics GA 909TH UT WOS:000227883100016 ER PT J AU Zhou, Z Colgren, R AF Zhou, Z Colgren, R TI A non-linear spacecraft attitude tracking controller for large non-constant rate commands SO INTERNATIONAL JOURNAL OF CONTROL LA English DT Article ID QUATERNION FEEDBACK; STABILIZATION AB A new non-linear tracking control algorithm based on an attitude error quaternion is studied in this paper. The control law developed here uses the commanded attitude rate without transformation into the body frame. The direct use of the commanded attitude rate simplifies the calculation of its derivative, which is used in the control law. The solutions and the equilibrium points of the closed-loop system, which is a time-varying non-linear system, are obtained in different scenarios. In order to analyse the stability of the system and the tracking performance, two different forms of perturbation dynamics with seven state variables are introduced. Local stability and performance analysis shows that the eigenvalues of the linearized perturbation dynamics are determined only by the gain matrices in the control algorithm and the inertia matrix. The existence of globally stable tracking control is proved using a Lyapunov function. Simulation results show that the spacecraft can track the commanded attitude and rate quickly for a non-zero acceleration rate command. C1 Titan Corp, NASA, Facil 4 & 5, Fairmont, WV 26554 USA. Univ Kansas, Dept Aerosp Engn, Lawrence, KS 66045 USA. RP Zhou, Z (reprint author), Titan Corp, NASA, Facil 4 & 5, Fairmont, WV 26554 USA. EM zhiqiang.zhou@ivv.nasa.gov NR 8 TC 5 Z9 5 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0020-7179 J9 INT J CONTROL JI Int. J. Control PD MAR 20 PY 2005 VL 78 IS 5 BP 311 EP 325 DI 10.1080/00207170500079779 PG 15 WC Automation & Control Systems SC Automation & Control Systems GA 936AQ UT WOS:000229825100001 ER PT J AU Lotsch, A Friedl, MA Anderson, BT Tucker, CJ AF Lotsch, A Friedl, MA Anderson, BT Tucker, CJ TI Response of terrestrial ecosystems to recent Northern Hemispheric drought SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CARBON SINK; CLIMATE; PRECIPITATION; VEGETATION; OCEAN; OSCILLATION; ATMOSPHERE; TIMESCALES; ATLANTIC; PATTERNS AB Satellite normalized difference vegetation index (NDVI) observations reveal large and geographically extensive decreases in vegetation activity in Eurasia and North America between 1999 and 2002. In 2001, 73% of central southwest Asia exhibited NDVI anomalies that were more than one standard deviation below 21-year average conditions, and in 2002, fully 95% of North America exhibited below-average NDVI. This episode of large-scale vegetation browning coincided with a prolonged period of below-normal precipitation in the Northern Hemisphere, which limited moisture availability for plant growth. Spatio-temporal dynamics of NDVI, precipitation, and sea surface temperature data reveal that synchronous patterns of ocean circulation anomalies in the Pacific, Atlantic, and Indo-Pacific are strongly correlated with observed joint variability in NDVI and precipitation in the Northern Hemisphere during this period. C1 World Bank, Dev Res Grp, Washington, DC 20433 USA. Boston Univ, Dept Geog, Ctr Remote Sensing, Boston, MA 02215 USA. NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. RP Lotsch, A (reprint author), World Bank, Dev Res Grp, 1818 H St NW, Washington, DC 20433 USA. EM alotsch@worldbank.org; friedl@bu.edu; brucea@bu.edu; compton@ltpmailx.gsfc.nasa.org NR 28 TC 56 Z9 59 U1 2 U2 14 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 19 PY 2005 VL 32 IS 6 AR L06705 DI 10.1029/2004GL022043 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 909QD UT WOS:000227874500003 ER PT J AU Petropavlovskikh, I Ahn, C Bhartia, PK Flynn, LE AF Petropavlovskikh, I Ahn, C Bhartia, PK Flynn, LE TI Comparison and covalidation of ozone anomalies and variability observed in SBUV(/2) and Umkehr northern midlatitude ozone profile estimates SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TRENDS AB This analysis presents comparisons of upper-stratosphere ozone information observed by two independent systems: the Solar Backscatter UltraViolet (SBUV and SBUV/2) satellite instruments, and ground-based Dobson spectrophotometers. Both the new SBUV Version 8 and the new UMK04 profile retrieval algorithms are optimized for studying long-term variability and trends in ozone. Trend analyses of the ozone time series from the SBUV(/2) data set are complex because of the multiple instruments involved, changes in the instruments' geolocation, and short periods of overlaps for inter-calibrations among different instruments. Three northern middle latitudes Dobson ground stations (Arosa, Boulder, and Tateno) are used in this analysis to validate the trend quality of the combined 25-year SBUV/2 time series, 1979 to 2003. Generally, differences between the satellite and ground-based data do not suggest any significant time-dependent shifts or trends. The shared features confirm the value of these data sets for studies of ozone variability. C1 NOAA, RARL, Boulder, CO 80305 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NOAA, Natl Environm Satellite Data & Informat Serv Head, Camp Springs, MD 20746 USA. RP Petropavlovskikh, I (reprint author), NOAA, RARL, 325 Broadway, Boulder, CO 80305 USA. EM irina.petro@noaa.gov RI Flynn, Lawrence/B-6321-2009; Bhartia, Pawan/A-4209-2016 OI Flynn, Lawrence/0000-0001-6856-2614; Bhartia, Pawan/0000-0001-8307-9137 NR 14 TC 16 Z9 16 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 19 PY 2005 VL 32 IS 6 AR L06805 DI 10.1029/2004GL022002 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 909QD UT WOS:000227874500002 ER PT J AU Eck, TF Holben, BN Dubovik, O Smirnov, A Goloub, P Chen, HB Chatenet, B Gomes, L Zhang, XY Tsay, SC Ji, Q Giles, D Slutsker, I AF Eck, TF Holben, BN Dubovik, O Smirnov, A Goloub, P Chen, HB Chatenet, B Gomes, L Zhang, XY Tsay, SC Ji, Q Giles, D Slutsker, I TI Columnar aerosol optical properties at AERONET sites in central eastern Asia and aerosol transport to the tropical mid-Pacific SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SKY RADIANCE MEASUREMENTS; SINGLE SCATTERING ALBEDO; ACE-ASIA; TROPOSPHERIC AEROSOLS; MAUNA-LOA; ANTHROPOGENIC EMISSIONS; WAVELENGTH DEPENDENCE; RADIATIVE PROPERTIES; SEASONAL-VARIATIONS; LIDAR MEASUREMENTS AB [1] The column-integrated optical properties of aerosol in the central eastern region of Asia and midtropical Pacific were investigated based on Sun/sky radiometer measurements made at Aerosol Robotic Network (AERONET) sites in these regions. Characterization of aerosol properties in the Asian region is important due to the rapid growth of both population and economic activity, with associated increases in fossil fuel combustion, and the possible regional and global climatic impacts of related aerosol emissions. Multiyear monitoring over the complete annual cycle at sites in China, Mongolia, South Korea, and Japan suggest spring and/or summer maximum in aerosol optical depth (tau(a)) and a winter minimum; however, more monitoring is needed to establish accurate climatologies. The annual cycle of Angstrom wavelength exponent (alpha) showed a springtime minimum associated with dust storm activity; however, the monthly mean alpha(440)-(870) was > 0.8 even for the peak dust season at eastern Asian sites suggesting that fine mode pollution aerosol emitted from population centers in eastern Asia dominates the monthly aerosol optical influence even in spring as pollution aerosol mixes with coarse mode dust originating in western source regions. Aerosol optical depth peaks in spring in the tropical mid-Pacific Ocean associated with seasonal shifts in atmospheric transport from Asia, and similar to 35% of the springtime tau(a500) enhancement occurs at altitudes above 3.4 km. For predominately fine mode aerosol pollution cases, the average midvisible (similar to 550 nm) single scattering albedo (omega(0)) at two continental urban sites in China averaged similar to 0.89, while it was significantly higher, similar to 0.93, at two relatively rural coastal sites in South Korea and Japan. Differences in fine mode absorption between these regions may result from a combination of factors including aerosol aging during transport, relative humidity differences, sea salt at coastal sites, and fuel type and combustion differences in the two regions. For cases where tau(a) was predominately coarse mode dust aerosol in the spring of 2001, the absorption was greater in eastern Asia compared to the source regions, with omega(0) at Dunhuang, China (near to the major Taklamakan dust source), similar to 0.04 higher than at Beijing at all wavelengths, and Anmyon, South Korea, showing an intermediate level of absorption. Possible reasons for differences in dust absorption magnitude include interactions between dust and fine mode pollution aerosol and also variability of dust optical properties from different source regions in China and Mongolia. C1 NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. Univ Paris, LISA, F-7583 Creteil, France. Chinese Acad Sci, Inst Atmospher Phys, Beijing 100029, Peoples R China. Univ Sci & Tech Lille Flandres Artois, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France. MNPCA, GMEI, CNRM, Meteo France,CNRS, F-31057 Toulouse, France. NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. Chinese Acad Sci, Inst Earth Environm, Xian 710075, Peoples R China. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP NASA, Goddard Space Flight Ctr, Biospher Sci Branch, Greenbelt, MD 20771 USA. EM teck@ltpmail.gsfc.nasa.gov RI Dubovik, Oleg/A-8235-2009; Smirnov, Alexander/C-2121-2009; ECK, THOMAS/D-7407-2012; Tsay, Si-Chee/J-1147-2014 OI Dubovik, Oleg/0000-0003-3482-6460; Smirnov, Alexander/0000-0002-8208-1304; NR 60 TC 239 Z9 251 U1 8 U2 39 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 MAR 18 PY 2005 VL 110 IS D6 AR D06202 DI 10.1029/2004JD005274 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 909QI UT WOS:000227875100003 ER PT J AU Michalsky, JJ Dolce, R Dutton, EG Haeffelin, M Jeffries, W Stoffel, T Hickey, J Los, A Mathias, D McArthur, LJB Nelson, D Philipona, R Reda, I Rutledge, K Zerlaut, G Forgan, B Kiedron, P Long, C Gueymard, C AF Michalsky, JJ Dolce, R Dutton, EG Haeffelin, M Jeffries, W Stoffel, T Hickey, J Los, A Mathias, D McArthur, LJB Nelson, D Philipona, R Reda, I Rutledge, K Zerlaut, G Forgan, B Kiedron, P Long, C Gueymard, C TI Toward the development of a diffuse horizontal shortwave irradiance working standard SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CLOUD-FREE SKIES; SOLAR IRRADIANCE; THERMAL OFFSET; SURFACE; PYRANOMETER AB [1] The first intensive observation period (IOP) to simultaneously measure diffuse horizontal shortwave irradiance (scattered solar radiation that falls on a horizontal surface) with a wide array of shaded pyranometers suggested that a consensus might be reached that would permit the establishment of a standard with a smaller uncertainty than previously achieved. A second IOP has been held to refine the first IOP measurements using a uniform calibration protocol, offset corrections for all instruments and validation of those corrections, improvements in some of the instruments, and better data acquisition. The venue for both IOPs was the Department of Energy's Atmospheric Radiation Measurement central facility in northern Oklahoma. The 9 days of measurements in October 2003 included a better mixture of clear and overcast conditions than during the first IOP and revealed considerable differences among the instruments' responses for different cloud conditions. Four of the 15 instruments were eliminated as candidates to be included in the standard because of noisy signals, inadequate offset correction, or instability with respect to the majority of the measurements. Eight pyranometers agreed to within +/- 2% for clear-sky conditions. Three others have a high bias on clear days relative to these eight, but all 11 agree within +/- 2% on overcast days. The differences and causes of this behavior under clear and cloudy skies are examined. C1 NOAA, Air Resources Lab, Surface Radiat Res Branch, RARL, Boulder, CO 80305 USA. Kipp & Zonen Inc, Bohemia, NY 11716 USA. NOAA, RECGI, Climate Monitoring & Diagnost Lab, Boulder, CO 80305 USA. Bur Meteorol, Australian Reg Instrument Ctr, Melbourne, Vic 3000, Australia. Solar Consulting Serv, New Smyrna Beach, FL 32816 USA. Ecole Polytech, IPSL, LMD, F-91128 Palaiseau, France. Eppley Lab Inc, Newport, RI 02840 USA. Yankee Environm Syst Inc, Turners Falls, MA 01376 USA. SUNY Albany, Atmospher Sci Res Ctr, Albany, NY 12203 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. Carter Scott Design, Brunswick, Vic 3056, Australia. Meteorol Serv Canada, Toronto, ON M3H 5T4, Canada. World Radiat Ctr, Phys Meterol Observ, CH-7260 Davos, Switzerland. Natl Renewable Energy Lab, Golden, CO 80401 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. EKO Instruments Co Ltd, Shibuya Ku, Tokyo 1510073, Japan. RP Michalsky, JJ (reprint author), NOAA, Air Resources Lab, Surface Radiat Res Branch, RARL, 325 Broadway, Boulder, CO 80305 USA. EM joseph.michalsky@noaa.gov NR 16 TC 14 Z9 16 U1 1 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 MAR 18 PY 2005 VL 110 IS D6 AR D06107 DI 10.1029/2004JD005265 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 909QI UT WOS:000227875100002 ER PT J AU Remsberg, EE Deaver, LE AF Remsberg, EE Deaver, LE TI Interannual, solar cycle, and trend terms in middle atmospheric temperature time series from HALOE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LONG-TERM; MESOSPHERIC TEMPERATURE; OCCULTATION EXPERIMENT; LOWER STRATOSPHERE; BIENNIAL OSCILLATION; UV VARIABILITY; OZONE; MODEL; QBO AB [1] Temperature versus pressure or T(p) time series from the Halogen Occultation Experiment (HALOE) have been generated and analyzed for the period of 1991-2004 and for the mesosphere and upper stratosphere for latitude zones from 40N to 40S. Multiple linear regression (MLR) techniques were used for the analysis of the seasonal and the significant interannual and solar cycle (or decadal-scale) terms. An 11-yr solar cycle (SC) term of amplitude 0.5 to 1.7 K was found for the middle to upper mesosphere; its phase was determined by a Fourier fit to the de-seasonalized residual. This SC term is largest and has a lag of several years for northern hemisphere middle latitudes of the middle mesosphere, perhaps due to the interfering effects of wintertime wave dissipation. The SC response from the MLR models is weaker but essentially in-phase at low latitudes and in the southern hemisphere. An in-phase SC response term is also significant near the tropical stratopause with an amplitude of about 0.4 to 0.6 K, which is somewhat less than predicted from models. Both sub-biennial (688-dy) and QBO (800-dy) terms are resolved for the mid to upper stratosphere along with a decadal-scale term that is presumed to have a 13.5-yr period due to their predicted modulation. This decadal-scale term is out-of-phase with the SC during 1991-2004. However, the true nature and source of this term is still uncertain, especially at 5 hPa. Significant linear cooling trends ranging from -0.3 K to -1.1 K per decade were found in the tropical upper stratosphere and subtropical mesosphere. Trends have not emerged so far for the tropical mesosphere, so it is concluded that the cooling rates that have been resolved for the subtropics are likely upper limits. As HALOE-like measurements continue and their time series lengthen, it is anticipated that better accuracy can be achieved for these interannual, SC, and trend terms. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP NASA, Langley Res Ctr, Mail Stop 401B, Hampton, VA 23681 USA. EM e.e.remsberg@larc.nasa.gov; l.e.deaver@larc.nasa.gov NR 37 TC 34 Z9 34 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 MAR 18 PY 2005 VL 110 IS D6 AR D06106 DI 10.1029/2004JD004905 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 909QI UT WOS:000227875100001 ER PT J AU Whang, YC Wang, YM Sheeley, NR Burlaga, LF AF Whang, YC Wang, YM Sheeley, NR Burlaga, LF TI Global structure of the out-of-ecliptic solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TERMINATION SHOCK; MAGNETIC-FIELD; SPEED; CYCLE; SCINTILLATION; HELIOSPHERE; EVOLUTION; VELOCITY; LATITUDE; MAXIMUM AB We use the observed photospheric field maps and the wind speed observed from Ulysses to study the out-of-ecliptic solar wind. The model calculates the wind speed from the rate of magnetic flux tube expansion factors using a conversion function that is determined by least squares fit of all currently available data from Ulysses. Using the best fit conversion function, we investigate the global solar wind covering a 36-year period from 1968 through 2003. The results complement and expand upon earlier studies conducted with interplanetary scintillation and other in situ spacecraft observations. The rotationally averaged wind speed is a function of two parameters: the heliolatitude and the phase of the solar cycle. The out-of-ecliptic solar wind has a recurrent stable structure, and the average wind speed varies like a sine square of latitude profile spanning more than 5 years during the declining phase and solar minimum in each solar cycle. Ulysses has observed this stable structure in its first polar orbit in 1992-1997. Near solar maximum the structure of the out-of-ecliptic solar wind is in a transient state lasting 2-3 years when the stable structure breaks down during the disappearance and reappearance of the polar coronal holes. C1 Catholic Univ Amer, Dept Mech Engn, Washington, DC 20064 USA. USN, Res Lab, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Catholic Univ Amer, Dept Mech Engn, Washington, DC 20064 USA. EM whang@cua.edu; ywang@yucca.nrl.navy.mil; sheeley@spruce.nrl.navy.mi; burlaga@lepvax.gsfc.nasa.gov NR 35 TC 18 Z9 18 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 18 PY 2005 VL 110 IS A3 AR A03101 DI 10.1029/2004JA010875 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 909SK UT WOS:000227880800001 ER PT J AU Wang, J Dyers, L Mason, R Amoyaw, P Bu, XR AF Wang, J Dyers, L Mason, R Amoyaw, P Bu, XR TI Highly efficient and direct heterocyclization of dipyridyl ketone to N,N-bidentate ligands SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID CATALYZED OXIDATIVE HETEROCYCLIZATION; ATMOSPHERIC OXYGEN; DERIVATIVES; COMPLEXES; LIGHT; IMIDAZO<1,5-A>PYRIDINES; TRIPHENYLAMINE; CHROMOPHORES; DEVICES; SYSTEMS AB Reaction of various aromatic aldehydes with 2,2'-dipyridyl ketone and ammonium acetate in hot acetic acid provides ready access to a series of substituted 1-pyridylimidazo[1,5-a]pyridines, a class of ligands possessing an N,N-bidentate feature, in good yields. C1 Clark Atlanta Univ, Dept Chem, Lab Electroopt Mat, Atlanta, GA 30314 USA. Clark Atlanta Univ, NASA, Ctr High Performance Polymers & Composites, Atlanta, GA 30314 USA. RP Bu, XR (reprint author), Clark Atlanta Univ, Dept Chem, Lab Electroopt Mat, Atlanta, GA 30314 USA. EM xbu@cau.edu FU NCRR NIH HHS [G12-RR03062] NR 36 TC 45 Z9 45 U1 2 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD MAR 18 PY 2005 VL 70 IS 6 BP 2353 EP 2356 DI 10.1021/jo047853k PG 4 WC Chemistry, Organic SC Chemistry GA 905KG UT WOS:000227566400057 PM 15760230 ER PT J AU Mohageg, M Savchenkov, A Strekalov, D Matsko, A Ilchenko, V Maleki, L AF Mohageg, M Savchenkov, A Strekalov, D Matsko, A Ilchenko, V Maleki, L TI Reconfigurable optical filter SO ELECTRONICS LETTERS LA English DT Article ID OPTOELECTRONIC MICROWAVE-OSCILLATOR AB A narrowband, widely tunable optical filter with a reconfigurable spectrum is proposed, and the critical component for the filter operation is demonstrated. The filter is based on a whispering gallery mode resonator made of domain engineered LiNbO3 crystal. The main feature of the filter is tunability of the spacing between some of the optical modes of the resonator. The spacing is electro-optically manipulated at 7 GHz in the linear regime with approximately 21 MHz/V tuning rate. The filter operates at 1.55 mu m wavelength, and is characterised with 10 MHz bandwidth, 5 dB fibre-to-fibre insertion loss and 20 ns tuning speed. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mohageg, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM andrey.matsko@jpl.nasa.gov RI Matsko, Andrey/A-1272-2007 NR 4 TC 5 Z9 5 U1 0 U2 1 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 MAR 17 PY 2005 VL 41 IS 6 BP 356 EP 358 DI 10.1049/el:20058050 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 910CC UT WOS:000227906000046 ER PT J AU Sadana, AK Liang, F Brinson, B Arepalli, S Farhat, S Hauge, RH Smalley, RE Billups, WE AF Sadana, AK Liang, F Brinson, B Arepalli, S Farhat, S Hauge, RH Smalley, RE Billups, WE TI Functionalization and extraction of large fullerenes and carbon-coated metal formed during the synthesis of single wall carbon nanotubes by laser oven, direct current arc, and high-pressure carbon monoxide production methods SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID HIPCO PROCESS; NOBLE-GASES; GROWTH; PHASE; SOOT AB Large fullerenes and carbon-coated metal nanoparticles that are formed during the synthesis of carbon nanotubes have been functionalized by the addition of alkyl radicals and isolated by extraction into chloroform. The soluble, functionalized fullerenes have been isolated from raw single-wall carbon nanotube (SWNT) material prepared by laser oven, direct current arc, and high-pressure carbon monoxide production methods. Analyses of the extracted large fullerenes were carried out by thermogravimetric analysis, UV-vis-near-IR, laser desorption ionization mass spectrometry, and high-resolution transmission electron microscopy. C1 Rice Univ, Dept Chem, Houston, TX 77005 USA. Rice Univ, Ctr Nanoscale Sci & Technol, Houston, TX 77005 USA. NASA, Johnson Space Ctr, GB Tech, Houston, TX 77058 USA. Univ Paris 13, F-93430 Villetaneuse, France. RP Billups, WE (reprint author), Rice Univ, Dept Chem, 6100 Main St, Houston, TX 77005 USA. EM billups@rice.edu RI Hauge, Robert/A-7008-2011; Arepalli, Sivaram/A-5372-2010 OI Hauge, Robert/0000-0002-3656-0152; NR 18 TC 24 Z9 24 U1 0 U2 0 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 MAR 17 PY 2005 VL 109 IS 10 BP 4416 EP 4418 DI 10.1021/jp045582b PG 3 WC Chemistry, Physical SC Chemistry GA 906GV UT WOS:000227629700019 PM 16851511 ER PT J AU Yang, CR Shapiro, BE Mjolsness, ED Hatfield, GW AF Yang, CR Shapiro, BE Mjolsness, ED Hatfield, GW TI An enzyme mechanism language for the mathematical modeling of metabolic pathways SO BIOINFORMATICS LA English DT Article ID ESCHERICHIA-COLI; SIMULATION; SYSTEM AB Motivation: As a first step toward the elucidation of the systems biology of complex biological systems, it was our goal to mathematically model common enzyme catalytic and regulatory mechanisms that repeatedly appear in biological processes such as signal transduction and metabolic pathways. Results: We describe kMech, a Cellerator language extension that describes a suite of enzyme mechanisms. Each enzyme mechanism is parsed by kMech into a set of fundamental association-dissociation reactions that are translated by Cellerator into ordinary differential equations that are numerically solved by Mathematica (TM). In addition, we present methods that use commonly available kinetic measurements to estimate rate constants required to solve these differential equations. C1 Univ Calif Irvine, Coll Med, Dept Microbiol & Mol Genet, Irvine, CA 92697 USA. Univ Calif Irvine, Sch Informat & Comp Sci, Irvine, CA 92697 USA. Univ Calif Irvine, Inst Genom & Bioinformat, Irvine, CA 92697 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Hatfield, GW (reprint author), Univ Calif Irvine, Coll Med, Dept Microbiol & Mol Genet, Irvine, CA 92697 USA. EM emj@uci.edu; gwhat-fie@uci.edu RI Infante, Diogenes/A-8444-2015 OI Infante, Diogenes/0000-0002-8312-2198 FU NIGMS NIH HHS [GM55073, GM68903]; NLM NIH HHS [T15 LM-07443] NR 21 TC 27 Z9 30 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD MAR 15 PY 2005 VL 21 IS 6 BP 774 EP 780 DI 10.1093/bioinformatics/bti068 PG 7 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Computer Science, Interdisciplinary Applications; Mathematical & Computational Biology; Statistics & Probability SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Computer Science; Mathematical & Computational Biology; Mathematics GA 905IQ UT WOS:000227562200009 PM 15509612 ER PT J AU Brandon, AD Humayun, M Puchtel, IS Zolensky, ME AF Brandon, AD Humayun, M Puchtel, IS Zolensky, ME TI Re-Os isotopic systematics and platinum group element composition of the Tagish Lake carbonaceous chondrite SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HIGHLY SIDEROPHILE ELEMENTS; EARLY CORE FORMATION; EARTHS UPPER-MANTLE; HF-W CHRONOMETRY; REFRACTORY INCLUSIONS; RE-187-OS-187 SYSTEMATICS; OS-186-OS-187 SYSTEMATICS; EARLY DIFFERENTIATION; TERRESTRIAL PLANETS; TRACE-ELEMENTS AB The Tagish Lake meteorite is a primitive C2 chondrite that has undergone aqueous alteration shortly after formation of its parent body. Previous work indicates that if this type of material was part of a late veneer during terrestrial planetary accretion, it could provide a link between atmophile elements such as H, C, N and noble gases, and highly siderophile element replenishment in the bulk silicate portions of terrestrial planets following core formation. The systematic Re-Os isotope and highly siderophile element measurements performed here on five separate fractions indicate that while Tagish Lake has amongst the highest Ru/Ir (1.63 +/- 0.08), Pd/Ir (1.19 +/- 0.06) and Os-187/Os-188 (0.12564-0.12802) of all carbonaceous chondrites, these characteristics still fall short of those necessary to explain the observed siderophile element systematics of the primitive upper mantles of Earth and Mars. Hence, a direct link between atmophile and highly siderophile elements remains elusive, and other sources for replenishment are required, unless an as yet poorly constrained process fractionated Re/Os, Ru/Ir, and Pd/Ir following late accretion on both the Earth and Mars mantles. The unique elevated Ru/Ir combined with elevated Os-187/Os-188 of Tagish Lake may be attributed to Ru and Re mobility during aqueous alteration very early in its parent body history. The Os, Ir, Pt, and Pd abundances of Tagish Lake are similar to Cl chondrites. The elevated Ru/Ir and the higher Re/Os and consequent Os-187/Os-188 in Tagish Lake, are balanced by a lower Ru/Ir and lower Re/Os and Os-187/Os-188 in CM-chondrites, relative to Cl chondrites. A model that links Tagish Lake with CI and CM chondrites in the same parent body may explain the observed systematics. In this scenario, CM chondrite material comprises the exterior, grading downward to Tagish Lake material, which grades to Cl material in the interior of the parent body. Aqueous alteration intensifies towards the interior with increasing temperature. Ruthenium and Re are mobilized from the CM layer into the Tagish Lake layer. This model may thus provide a potential direct parent body relationship between three separate groups of carbonaceous chondrites. Copyright (c) 2005 Elsevier Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. RP Brandon, AD (reprint author), NASA, Lyndon B Johnson Space Ctr, Mail Code SR, Houston, TX 77058 USA. EM alan.d.brandon1@jsc.nasa.gov OI Humayun, Munir/0000-0001-8516-9435 NR 80 TC 36 Z9 37 U1 1 U2 9 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 MAR 15 PY 2005 VL 69 IS 6 BP 1619 EP 1631 DI 10.1016/j.gca.2004.10.005 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 913CC UT WOS:000228126900018 ER PT J AU Ostgaard, N Tsyganenko, NA Mende, SB Frey, HU Immel, TJ Fillingim, M Frank, LA Sigwarth, JB AF Ostgaard, N Tsyganenko, NA Mende, SB Frey, HU Immel, TJ Fillingim, M Frank, LA Sigwarth, JB TI Observations and model predictions of substorm auroral asymmetries in the conjugate hemispheres SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; DAWN-DUSK ASYMMETRY; SOLAR-WIND; MAGNETOSPHERE; IMF; MAGNETOTAIL; IONOSPHERE; DEPENDENCE; COMPONENT; LOCATION AB Based on imaging data from the Polar VIS Earth camera and the IMAGE-FUV instruments we have documented how the IMF orientation and the dipole tilt angle act as the main and the secondary controlling factors of the relative displacement of the aurora in the conjugate hemispheres. Comparing our results with the asymmetries predicted by recent empirical magnetospheric models, we show that the assumed partial penetration of the IMF into the magnetosphere is clearly supported by observations, but the modeled conjugate shifts were found to be an order of magnitude smaller than the observed ones. C1 Univ Bergen, Dept Phys & Technol, Bergen, Norway. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Ostgaard, N (reprint author), Univ Norway, Dept Phys & Technol, Allegt 55, N-5007 Bergen, Norway. EM nikolai.ostgaard@ift.uib.no RI Tsyganenko, Nikolai/J-7377-2012 OI Tsyganenko, Nikolai/0000-0002-5938-1579 NR 27 TC 37 Z9 37 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 15 PY 2005 VL 32 IS 5 AR L05111 DI 10.1029/2004GL022166 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 909PY UT WOS:000227873900004 ER PT J AU Anilkumar, AV Grugel, RN Bhowmick, J Wang, TG AF Anilkumar, AV Grugel, RN Bhowmick, J Wang, TG TI Suppression of thermocapillary oscillations in sodium nitrate floating half-zones by high-frequency end-wall vibrations SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE thermocapillary convection; fluid flows; floating-zone technique; microgravity conditions ID LIQUID BRIDGE; CRYSTAL-GROWTH; TEMPERATURE-FLUCTUATIONS; CONVECTION; FLOW; SILICON; DRIVEN; MICROGRAVITY; INSTABILITY; SURFACE AB Experiments to suppress thermocapillary oscillations by using high-frequency end-wall vibrations were carried out in sodium nitrate floating half-zones. Such a half-zone is formed by melting one end of a vertically held sodium nitrate crystal rod in contact with a hot surface at the top. Thermocapillary convection occurs in the melt due to the imposed temperature gradient at the free surface. When this temperature gradient is large enough, steady thermocapillary convection becomes unstable, and thermocapillary oscillations occur. In such a context, the bottom end of the crystal rod was vibrated at a high frequency to generate a streaming flow in a direction opposite to that of thermocapillary convection. It is observed that by generating a sufficiently strong streaming flow, the thermocapillary oscillations can be quenched everywhere in the melt zone. (c) 2004 Elsevier B.V. All rights reserved. C1 Vanderbilt Univ, Nashville, TN 37235 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Anilkumar, AV (reprint author), Vanderbilt Univ, 1592-B, Nashville, TN 37235 USA. EM anil@vuse.vanderbilt.edu NR 21 TC 5 Z9 5 U1 0 U2 5 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 MAR 15 PY 2005 VL 276 IS 1-2 BP 194 EP 203 DI 10.1016/j.jcrysgro.2004.11.344 PG 10 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 914HL UT WOS:000228218300028 ER PT J AU Cooper, OR Stohl, A Eckhardt, S Parrish, DD Oltmans, SJ Johnson, BJ Nedelec, P Schmidlin, FJ Newchurch, MJ Kondo, Y Kita, K AF Cooper, OR Stohl, A Eckhardt, S Parrish, DD Oltmans, SJ Johnson, BJ Nedelec, P Schmidlin, FJ Newchurch, MJ Kondo, Y Kita, K TI A springtime comparison of tropospheric ozone and transport pathways on the east and west coasts of the United States SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AIR-POLLUTION TRANSPORT; INCREASING BACKGROUND OZONE; PARTICLE DISPERSION MODEL; NORTH-ATLANTIC; ASIAN EMISSIONS; PACIFIC; CLIMATOLOGY; AIRCRAFT; EPISODES; AMERICA AB We have conducted a study to determine the influence of Asian pollution plumes on free tropospheric ozone above the west coast of the United States during spring. We also explored the additional impact of North American emissions on east coast free tropospheric ozone. Long-term ozone monitoring sites in the United States are few, but we obtained ozonesonde profiles from Trinidad Head on the west coast, Huntsville, Alabama, in the southeast, and Wallops Island, Virginia, on the east coast. Additional east coast ozone profiles were measured by the MOZAIC commercial aircraft at Boston, New York City, and Philadelphia. Kilometer-averaged ozone was compared between Trinidad Head and the three east coast sites (MOZAIC, Wallops Island, and Huntsville). Only in the 0-1 km layer did the MOZAIC site have a statistically significant greater amount of ozone than Trinidad Head. Likewise only the 0-1 and 1-2 km layers had greater ozone at Wallops Island and Huntsville in comparison to Trinidad Head. While Wallops Island did show greater ozone than Trinidad Head at 6-9 km, this excess ozone was attributed to a dry air mass sampling bias. A particle dispersion model was used to determine the surface source regions for each case, and the amount of anthropogenic NOx tracer that would have been emitted into each air mass. Transport times were limited to 20 days to focus on the impact of direct transport of pollution plumes from the atmospheric boundary layer. As expected, the amount of NOx tracer emitted into the east coast profiles was much greater in the lower and mid troposphere than at the west coast. At various altitudes at both coasts there existed a significant positive correlation between ozone and the NOx tracer, but the explained variance was generally less than 30%. On the east coast, Wallops Island had the weakest relationship between ozone and the NOx tracer, while Huntsville had the strongest. During spring, differences in photochemistry and transport pathways in the lowest 2 km of the troposphere results in an extra 5-14 ppbv of ozone on the east coast in comparison to Trinidad Head. However, despite differing amounts of NOx tracer from Asia and North America in the free troposphere, we found no significant difference in free tropospheric ozone between the east and west coasts of the United States during spring. C1 NOAA, Aeron Lab, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Tech Univ Munich, Dept Ecol, D-8050 Freising Weihenstephan, Germany. NOAA, Climate Monitoring & Diagnost Lab, Boulder, CO 80303 USA. CNRS, OMP, Lab Aerol, Toulouse, France. NASA, Goddard Space Flight Ctr, Wallops Flight Facil, Wallops Isl, VA 23337 USA. Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35899 USA. Univ Tokyo, Adv Sci & Technol Res Ctr, Tokyo, Japan. RP NOAA, Aeron Lab, R-AL4,325 Broadway, Boulder, CO 80305 USA. EM owen.r.cooper@noaa.gov RI Stohl, Andreas/A-7535-2008; Parrish, David/E-8957-2010; Kondo, Yutaka/D-1459-2012; Cooper, Owen/H-4875-2013; Eckhardt, Sabine/I-4001-2012 OI Stohl, Andreas/0000-0002-2524-5755; Parrish, David/0000-0001-6312-2724; Eckhardt, Sabine/0000-0001-6958-5375 NR 46 TC 29 Z9 29 U1 1 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 15 PY 2005 VL 110 IS D5 AR D05S90 DI 10.1029/2004JD005183 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 909QG UT WOS:000227874800003 ER PT J AU Tsyganenko, NA Sitnov, MI AF Tsyganenko, NA Sitnov, MI TI Modeling the dynamics of the inner magnetosphere during strong geomagnetic storms SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ASYMMETRIC RING CURRENT; DAWN-DUSK ASYMMETRY; MAGNETIC STORMS; SOLAR-WIND; BIRKELAND CURRENTS; GROWTH-PHASE; FIELD; SUBSTORM; TAIL; DST AB [1] This work builds on and extends our previous effort (Tsyganenko et al., 2003) to develop a dynamical model of the storm-time geomagnetic field in the inner magnetosphere, using space magnetometer data taken during 37 major events in 1996-2000 and concurrent observations of the solar wind and interplanetary magnetic field (IMF). The essence of the approach is to derive from the data the temporal variation of all major current systems contributing to the distant geomagnetic field during the entire storm cycle, using a simple model of their growth and decay. Each principal source of the external magnetic field (magnetopause, cross-tail current sheet, axisymmetric and partial ring currents, and Birkeland current systems) is driven by a separate variable, calculated as a time integral of a combination of geoeffective parameters N-lambda V-beta B-s(gamma), where N, V, and B-s are the solar wind density, speed, and the magnitude of the southward component of the IMF, respectively. In this approach we assume that each source has its individual relaxation timescale and residual quiet-time strength, and its partial contribution to the total field depends on the entire history of the external driving of the magnetosphere during a storm. In addition, the magnitudes of the principal field sources were assumed to saturate during extremely large storms with abnormally strong external driving. All the parameters of the model field sources, including their magnitudes, geometrical characteristics, solar wind/IMF driving functions, decay timescales, and saturation thresholds, were treated as free variables, and their values were derived from the data. As an independent consistency test, we calculated the expected Dst variation on the basis of the model output at Earth's surface and compared it with the actual observed Dst. A good agreement (cumulative correlation coefficient R = 0.92) was found, in spite of the fact that similar to 90% of the spacecraft data used in the fitting were taken at synchronous orbit and beyond, while only 3.7% of those data came from distances 2.5 <= R <= 4 R-E. The obtained results demonstrate the possibility to develop a truly dynamical model of the magnetic field, based on magnetospheric and interplanetary data and allowing one to reproduce and forecast the entire process of a geomagnetic storm, as it unfolds in time and space. C1 NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Lab Solar & Space Phys, Greenbelt, MD 20771 USA. Univ Maryland, Inst Res Elect & Appl Phys, College Pk, MD 20742 USA. RP Tsyganenko, NA (reprint author), NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Code 612-3, Greenbelt, MD 20771 USA. EM nikolai.tsyganenko@gsfc.nasa.gov; sitnov@umd.edu RI Tsyganenko, Nikolai/J-7377-2012; Sitnov, Mikhail/H-2316-2016 OI Tsyganenko, Nikolai/0000-0002-5938-1579; NR 33 TC 377 Z9 379 U1 2 U2 23 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 MAR 15 PY 2005 VL 110 IS A3 AR A03208 DI 10.1029/2004JA010798 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 909SH UT WOS:000227880500007 ER PT J AU Siebe, C Arana-Salinas, L Abrams, M AF Siebe, C Arana-Salinas, L Abrams, M TI Geology and radiocarbon ages of Tlaloc, Tlacotenco, Cuauhtzin, Hijo del Cuauhtzin, Teuhtli, and Ocusacayo monogenetic volcanoes in the central part of the Sierra Chichinautzin, Mexico SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE Cuauhtzin; Ocusacayo; Teuhtli; Tlacotenco; Chichinautzin; monogenetic volcano; radiocarbon; trans-Mexican Volcanic Belt; volcanic hazards ID HOLOCENE PELADO; CINDER CONES; SCORIA CONES; TIME SCALE; CITY; CALIBRATION; GUESPALAPA; SOUTH; BC AB Tlaloc, Tlacotenco, Cuauhtzin, Hijo del Cuauhtzin, Teuhtli, and Ocusacayo monogenetic volcanoes located within the Sierra del Chichinautzin Volcanic Field (SCVF) at the southern margin of Mexico City were studied to further refine attendant volcanic hazards in this heavily populated region. Based on fieldwork and Landsat imagery interpretation, a geologic map was produced, morphometric parameters characterizing the cones and lava flows were determined, and the areal extent and volumes of erupted products were estimated. The longest lava flow was produced by Tlacotenco and reached 9.5 km from its source; total areas covered by lava flows from each eruption range between 12.8 km(2) (Tlacotenco) and 54.4 km(2) (Tlaloc); and total erupted volumes range between 0.26 and 1.36 km(3) per volcano. Radiocarbon measurements of a paleosol underneath an ash layer from the Tlaloc scoria cone yielded an age of 6200 years BP, while charcoal found within block-and-ash flow and lahar deposits from Cuauhtzin dome yielded ages of 7360 and 8225 years BP, respectively. The Tlacotenco dacite lava flow overlies Popocatepetl's Tutti Frutti Plinian pumice fall deposit dated at 14,000 years BP and is therefore younger than this prominent stratigraphic marker. On the other hand, Teuhtli and Hijo del Cuauhtzin scoria cones and the Ocusacayo andesite lava flows are overlain by the Tutti Frutti and therefore older than 14,000 years BP. These new dates together with other published dates for scoria cones in the SCVF imply that the previously determined recurrence interval during the Holocene for monogenetic eruptions in the SCVF of < 1700 years [Siebe, C., Rodriguez-Lara, V., Schaaf, P., Abrams, M., 2004a. Radiocarbon ages of Holocene Pelado, Guespalapa, and Chichinautzin scoria cones, south of Mexico_City: implications for archaeology and future hazards. Bull. Volcanol. 66, 203-225.] needs to be corrected to < 1250 years. This means that the time of quiescence since the last eruption of the SCVF (1670 years BP) exceeds that of the estimated recurrence interval during the Holocene. (c) 2004 Elsevier B.V. All rights reserved. C1 Univ Nacl Autonoma Mexico, Inst Geofis, Mexico City 04510, DF, Mexico. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Siebe, C (reprint author), Univ Nacl Autonoma Mexico, Inst Geofis, Ciudad Univ, Mexico City 04510, DF, Mexico. EM csiebe@tonatiuh.igeofcu.unam.mx OI Siebe, Claus/0000-0002-3959-9028 NR 30 TC 36 Z9 38 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD MAR 15 PY 2005 VL 141 IS 3-4 BP 225 EP 243 DI 10.1016/j.jvolgeores.2004.10.009 PG 19 WC Geosciences, Multidisciplinary SC Geology GA 907RJ UT WOS:000227735300003 ER PT J AU Asmar, SW Armstrong, JW Iess, L Tortora, P AF Asmar, SW Armstrong, JW Iess, L Tortora, P TI Spacecraft Doppler tracking: Noise budget and accuracy achievable in precision radio science observations SO RADIO SCIENCE LA English DT Article ID GRAVITATIONAL-RADIATION; PHASE SCINTILLATION; SOLAR-WIND; FLUCTUATIONS; SPECTRUM; LINKS; BAND AB We discuss noise in Doppler tracking of deep space probes and provide a detailed noise model for Doppler radio science experiments. The most sensitive current experiments achieve fractional frequency fluctuation noise of about 3 x 10(-15) at 1000-s integration time, corresponding to better than 1 micron per second velocity noise. Our noise model focuses primarily on the Fourier range approximate to 10(-4) -1 Hz, but we briefly discuss noise in lower-frequency observations. We indicate applications of the noise model to experiment planning, identify phenomena limiting current Doppler sensitivity, and discuss the prospects for significant sensitivity improvements. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Roma La Sapienza, Dipartimento Ingn Aerospaziale & Astronaut, I-00184 Rome, Italy. Univ Bologna, Facolta Ingn 2, I-47110 Forli, Italy. RP Asmar, SW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM sami.asmar@jpl.nasa.gov RI IESS, Luciano/F-4902-2011; Tortora, Paolo/J-6191-2012 OI IESS, Luciano/0000-0002-6230-5825; Tortora, Paolo/0000-0001-9259-7673 NR 34 TC 51 Z9 51 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0048-6604 EI 1944-799X J9 RADIO SCI JI Radio Sci. PD MAR 15 PY 2005 VL 40 IS 2 AR RS2001 DI 10.1029/2004RS003101 PG 9 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Remote Sensing; Telecommunications GA 909SP UT WOS:000227881300001 ER PT J AU Garcia, CAE Garcia, VMT McClain, CR AF Garcia, CAE Garcia, VMT McClain, CR TI Evaluation of SeaWiFS chlorophyll algorithms in the Southwestern Atlantic and Southern Oceans SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE ocean color; SeaWiFS; chlorophyll; Southwestern Atlantic Ocean; Southern Ocean ID ANTARCTIC PENINSULA WATERS; BIOOPTICAL PROPERTIES; COLOR ALGORITHMS; SEA; VALIDATION; SURFACE; VARIABILITY; AMERICA; BIOMASS; REGION AB Bio-optical measurements of spectral upwelling radiance and surface chlorophyll-a concentration have been conducted during 15 cruises between 1995 and 2004. The bio-optical data were divided into two sub-sets: the Southwestern Atlantic Ocean (SwAO), comprising a variety of biogeochemical provinces, from the oligotrophic waters in the South Atlantic gyre to the coastal waters influenced by La Plata River and Palos Lagoon discharge, and the Southern Ocean (SO) data set, comprising sampling stations south of the mean position of the Polar Front, with most stations being located in the vicinity of the Antarctic Peninsula. We derived regional chlorophyll algorithms for both regions and comparisons were made with the NASA's OC4v4 (operational algorithm) and OC2v4. For the Southwestern Atlantic region, the NASA OC4v4 algorithm presented a reasonable performance (r(2)=0.87, rmse-L=0.475, N=136) as compared to the revised algorithm for SwAO data (r(2)=0.89, rmse-L=0.426, N=136). A few stations under strong river plume influence were not considered in the analyses. These were detected by a higher reflectance at 670 nm, at low in situ chlorophyll concentration (< 2 mg m(-3)). These results show that empirical algorithms applied to in-situ radiance data have a limited ability to extract accurate chlorophyll estimates below a 30% uncertainty level. For Southern Ocean stations, a 2-band linear-type model was generated (r(2)=0.64, rmse-L=0.347, N=77), which significantly improved the bias (6.4%) as compared to NASA's OC4v4 algorithm (bias=-21.7%). An evaluation of some published high-latitude algorithms on our data set has shown a better performance by taxon-specific models, even from distant regions. A validation experiment of the normalized spectral water-leaving radiances and chlorophyll-a SeaWiFS products was also conducted using the FURG-SwAO/SO data set, through a match-up exercise. Despite the relatively low number of pairs of radiometric measurements, SeaWiFS estimations compare well with in situ data (0.77 < r(2)< 0.98, N=21), although the satellite estimate show a marked bias (-35.6%) in the blue band nL(w) (412). Regarding the chlorophyll-a concentration, an overall agreement was observed (r(2)=0.77, rmse-L=0.66, N=28), with a mean absolute percentage difference of 66%, which is above the goal generally accepted of 35% for satellite ocean color chlorophyll estimates. For the studied Southern Ocean area (mainly the Bransfield Strait), NASA's OC4v4 algorithm systematically underestimates chlorophyll above 0.2 mg m(-3), as previously demonstrated by other researchers. (c) 2005 Elsevier Inc. All rights reserved. C1 Univ Fed Rio Grande, Dept Oceanog, Rio Grande, Brazil. Univ Fed Rio Grande, Dept Phys, Rio Grande, Brazil. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Univ Fed Rio Grande, Dept Oceanog, Rio Grande, Brazil. EM dfsgar@furg.br; docvmtg@furg.br; Charles.R.McClain@nasa.gov RI Tavano, Virginia/C-5241-2013; Garcia, Carlos/K-7382-2012 OI Tavano, Virginia/0000-0003-0039-8111; NR 46 TC 64 Z9 66 U1 0 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0034-4257 EI 1879-0704 J9 REMOTE SENS ENVIRON JI Remote Sens. Environ. PD MAR 15 PY 2005 VL 95 IS 1 BP 125 EP 137 DI 10.1016/j.rse.2004.12.006 PG 13 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 905BJ UT WOS:000227542200010 ER PT J AU Reid, JS Eck, TF Christopher, SA Koppmann, R Dubovik, O Eleuterio, DP Holben, BN Reid, EA Zhang, J AF Reid, JS Eck, TF Christopher, SA Koppmann, R Dubovik, O Eleuterio, DP Holben, BN Reid, EA Zhang, J TI A review of biomass burning emissions part III: intensive optical properties of biomass burning particles SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Review ID SINGLE-SCATTERING ALBEDO; SKY RADIANCE MEASUREMENTS; AEROSOL LIGHT-ABSORPTION; GLOBAL RADIATION BUDGET; FOREST-FIRE AEROSOLS; AMAZON BASIN; SIZE DISTRIBUTION; SOUTHERN AFRICA; SMOKE AEROSOL; WAVELENGTH DEPENDENCE AB Because of its wide coverage over much of the globe, biomass burning has been widely studied in the context of direct radiative forcing. Such study is warranted as smoke particles scatter and at times absorb solar radiation efficiently. Further, as much of what is known about smoke transport and impacts is based on remote sensing measurements, the optical properties of smoke particles have far reaching effects into numerous aspects of biomass burning studies. Global estimates of direct forcing have been widely varying, ranging from near zero to -1W m(-2). A significant part of this difference can be traced to varying assumptions on the optical properties of smoke. This manuscript is the third part of four examining biomass-burning emissions. Here we review and discuss the literature concerning measurement and modeling of optical properties of biomass-burning particles. These include available data from published sensitivity studies, field campaigns, and inversions from the Aerosol Robotic Network (AERONET) of Sun photometer sites. As a whole, optical properties reported in the literature are varied, reflecting both the dynamic nature of fires, variations in smoke aging processes and differences in measurement technique. We find that forward modeling or "internal closure" studies ultimately are of little help in resolving outstanding measurement issues due to the high degree of degeneracy in solutions when using "reasonable" input parameters. This is particularly notable with respect to index of refraction and the treatment of black carbon. Consequently, previous claims of column closure may in fact be more ambiguous. Differences between in situ and retrieved omega(o) values have implications for estimates of mass scattering and mass absorption efficiencies. In this manuscript we review and discuss this community dataset. Strengths and lapses are pointed out, future research topics are prioritized, and best estimates and uncertainties of key smoke particle parameters are provided. C1 USN, Res Lab, Marine Meteorol Div, Monterey, CA USA. Univ Maryland Baltimore Cty, GEST Ctr, Baltimore, MD 21228 USA. Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35899 USA. Forschungszentrum Juelich, Int Troposphaere 2, Inst Chem & Dynam Geosphaere, Julich, Germany. USN, Postgrad Sch, Dept Meteorol, Monterey, CA 93943 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP USN, Res Lab, Marine Meteorol Div, Monterey, CA USA. EM reidj@nrlmry.navy.mil RI Dubovik, Oleg/A-8235-2009; Christopher, Sundar/E-6781-2011; ECK, THOMAS/D-7407-2012; Reid, Jeffrey/B-7633-2014 OI Dubovik, Oleg/0000-0003-3482-6460; Reid, Jeffrey/0000-0002-5147-7955 NR 92 TC 208 Z9 209 U1 16 U2 90 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 MAR 14 PY 2005 VL 5 BP 827 EP 849 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 906BO UT WOS:000227615700002 ER PT J AU Jensen, EJ Smith, JB Pfister, L Pittman, JV Weinstock, EM Sayres, DS Herman, RL Troy, RF Rosenlof, K Thompson, TL Fridlind, AM Hudson, PK Cziczo, DJ Heymsfield, AJ Schmitt, C Wilson, JC AF Jensen, EJ Smith, JB Pfister, L Pittman, JV Weinstock, EM Sayres, DS Herman, RL Troy, RF Rosenlof, K Thompson, TL Fridlind, AM Hudson, PK Cziczo, DJ Heymsfield, AJ Schmitt, C Wilson, JC TI Ice supersaturations exceeding 100% at the cold tropical tropopause: implications for cirrus formation and dehydration SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID AEROSOL CHAMBER AIDA; IN-SITU MEASUREMENTS; LOWER STRATOSPHERE; SUBVISIBLE CIRRUS; RELATIVE-HUMIDITY; PARTICLE-SIZE; CLOUDS; TROPOSPHERE; AIRCRAFT; NUCLEI AB Recent in situ measurements at tropical tropopause temperatures as low as 187K indicate supersaturations with respect to ice exceeding 100% with little or no ice present. In contrast, models used to simulate cloud formation near the tropopause assume a supersaturation threshold for ice nucleation of about 65% based on laboratory measurements of aqueous aerosol freezing. The high supersaturations reported here, along with cloud simulations assuming a plausible range of temperature histories in the sampled air mass, indicate that the vast majority of aerosols in the air sampled on this flight must have had supersaturation thresholds for ice nucleation exceeding 100%( i.e. near liquid water saturation at these temperatures). Possible explanations for this high threshold are that (1) the expressions used for calculating vapor pressure over supercooled water at low temperatures give values are at least 20% too low, (2) organic films on the aerosol surfaces reduce their accommodation coefficient for uptake of water, resulting in aerosols with more concentrated solutions when moderate-rapid cooling occurs and correspondingly inhibited homogeneous freezing, and (3) if surface freezing dominates, organic coatings may increase the surface energy of the ice embryo/vapor interface resulting in suppressed ice nucleation. Simulations of in situ cloud formation in the tropical tropopause layer (TTL) throughout the tropics indicate that if decreased accommodation coefficients and resulting high thresholds for ice nucleation prevailed throughout the tropics, then the calculated occurrence frequency and areal coverage of TTL cirrus would be significantly suppressed. However, the simulations also show that even if in situ TTL cirrus form only over a very small fraction of the tropics in the western Pacific, enough air passes through them due to rapid horizontal transport such that they can still effectively freeze-dry air entering the stratosphere. The TTL cirrus simulations show that even if very large supersaturations are required for ice nucleation, these large supersaturations should occur very rarely. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Harvard Univ, Cambridge, MA 02138 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Calif Los Angeles, Los Angeles, CA USA. Natl Oceanog & Atmospher Adm, Aeron Lab, Boulder, CO USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ Denver, Denver, CO USA. RP NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM ejensen@cirrus.arc.nasa.gov RI Rosenlof, Karen/B-5652-2008; Fridlind, Ann/E-1495-2012; Herman, Robert/H-9389-2012; Schmitt, Carl/P-5490-2015; Heymsfield, Andrew/E-7340-2011 OI Rosenlof, Karen/0000-0002-0903-8270; Herman, Robert/0000-0001-7063-6424; NR 48 TC 64 Z9 64 U1 1 U2 11 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 MAR 14 PY 2005 VL 5 BP 851 EP 862 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 906BO UT WOS:000227615700003 ER PT J AU Anderson, AJ Blair, RG Hick, SM Kaner, RB AF Anderson, AJ Blair, RG Hick, SM Kaner, RB TI Metathesis routes to binary and ternary silicon nitrides. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Calif NanoSyst Inst, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. EM art.anderson@honeywell.com 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 MAR 13 PY 2005 VL 229 MA 586-INOR BP U1052 EP U1052 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177707584 ER PT J AU Anhar, AD Williams, GA Marshall, L Arnold, GL Lyons, TW AF Anhar, AD Williams, GA Marshall, L Arnold, GL Lyons, TW TI Tracking changes in ocean oxygenation with molybdenum isotopes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Arizona State Univ, Dept Chem & Biochem, Tempe, AZ 85287 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. Univ Calif Riverside, Dept Earth Sci, Riverside, CA 92521 USA. EM anbar@asu.edu RI Arnold, Gail/A-5572-2010 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 MAR 13 PY 2005 VL 229 MA 059-GEOC BP U891 EP U891 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177706367 ER PT J AU Blair, RG Kaner, RB AF Blair, RG Kaner, RB TI Synthesis and structure of cubic CaSiN2. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90024 USA. Univ Calif Los Angeles, Calif NanoSyst Inst, Los Angeles, CA USA. EM Blair@chem.ucla.edu NR 0 TC 0 Z9 0 U1 4 U2 8 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 MAR 13 PY 2005 VL 229 MA 588-INOR BP U1052 EP U1053 PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177707586 ER PT J AU Blaney, DL AF Blaney, DL TI Mars chemistry: Water, salts, and the evolution of the martian surface. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 NASA, Jet Prop Lab, Pasadena, CA 91109 USA. EM Diana.Blaney@jpl.nasa.gov 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 MAR 13 PY 2005 VL 229 BP U1186 EP U1186 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 008UQ UT WOS:000235066605457 ER PT J AU Brothers, EN Kudin, KN Scuseria, GE Bauschlicher, C AF Brothers, EN Kudin, KN Scuseria, GE Bauschlicher, C TI Transverse polarizability of carbon nanotubes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Rice Univ, Dept Chem, Houston, TX 77005 USA. Princeton Univ, PRISM, Princeton, NJ 08544 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM enb@rice.edu RI Kudin, Konstantin/A-7723-2008 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 MAR 13 PY 2005 VL 229 MA 355-COMP BP U810 EP U810 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177705675 ER PT J AU Chaban, GM AF Chaban, GM TI Rare gases inserted into biological building blocks: A theoretical study of glycine - Rg compounds (Rg=Xe, Kr, Ar) SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA 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 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 MAR 13 PY 2005 VL 229 MA 219-COMP BP U789 EP U789 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177705542 ER PT J AU Chahan, GM AF Chahan, GM TI Hydrogen bonding and vibrational spectroscopy: A theoretical study. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA 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 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 MAR 13 PY 2005 VL 229 MA 464-PHYS BP U773 EP U773 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 008UQ UT WOS:000235066603463 ER PT J AU Chen, P Robichaud, D Okumura, M AF Chen, P Robichaud, D Okumura, M TI Application of cavity enhanced, optical heterodyne spectroscopy to tropospheric isotope chemistry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Div Chem & Chem Engn, Pasadena, CA 91125 USA. EM Pin.Chen@jpl.nasa.gov RI Chen, Pin/B-1112-2008 OI Chen, Pin/0000-0003-1195-9666 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 MAR 13 PY 2005 VL 229 MA 131-PHYS BP U722 EP U722 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 008UQ UT WOS:000235066603131 ER PT J AU Cohn, CA Mueller, S Wimmer, E Leifer, ND Greenbaum, SG Schoonen, M AF Cohn, CA Mueller, S Wimmer, E Leifer, ND Greenbaum, SG Schoonen, M TI Mineral-generated reactive oxygen species. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 SUNY Stony Brook, Dept Geosci, Ctr Environm Mol Sci, Stony Brook, NY 11794 USA. NASA, Astrobiol Inst, Stony Brook, NY 11794 USA. CUNY Hunter Coll, Dept Phys, New York, NY 10021 USA. EM ccohn@ic.sunysb.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 MAR 13 PY 2005 VL 229 MA 017-GEOC BP U884 EP U884 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177706325 ER PT J AU Ewing, SA Michalski, G Wu, J Amundson, RG Thiemens, M McKay, CP AF Ewing, SA Michalski, G Wu, J Amundson, RG Thiemens, M McKay, CP TI Limited biology preserves atmospheric N in Atacama Desert soils. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Univ Calif Berkeley, Ecosyst Sci Div, Berkeley, CA 94720 USA. Univ Calif San Diego, Dept Chem & Biochem, San Diego, CA 92103 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 1 U2 8 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 MAR 13 PY 2005 VL 229 MA 046-GEOC BP U889 EP U889 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177706354 ER PT J AU Feldman, JD Judd, LM Liang, ML AF Feldman, JD Judd, LM Liang, ML TI Synthesis and properties of zirconium carbide derived from a zirconia/carbon gel. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 NASA, Ames Res Ctr, ELORET Corp, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Educ Associates, Moffett Field, CA 94035 USA. EM jayfeldman@sbcglobal.net 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 MAR 13 PY 2005 VL 229 MA 011-INOR BP U961 EP U961 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177707011 ER PT J AU Grant, SB Ahn, JH DiGiacomo, P Nezlin, N Jiang, S Surbeck, C AF Grant, SB Ahn, JH DiGiacomo, P Nezlin, N Jiang, S Surbeck, C TI Impact of storm water runoff on coastal water quality. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Univ Calif Irvine, Irvine, CA 92697 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. EM sbgrant@uci.edu RI DiGiacomo, Paul/F-5584-2010; Jiang, Sunny/H-7702-2012; Grant, Stanley/K-8179-2016 OI DiGiacomo, Paul/0000-0003-4550-1899; Jiang, Sunny/0000-0002-4993-8038; Grant, Stanley/0000-0001-6221-7211 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 MAR 13 PY 2005 VL 229 MA 060-COLL BP U638 EP U638 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177704221 ER PT J AU Hergenrother, PM AF Hergenrother, PM TI Overview of quinoxaline polymers. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. EM p.m.hergenrother@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 MAR 13 PY 2005 VL 229 MA 146-PMSE BP U1125 EP U1125 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 008UQ UT WOS:000235066605146 ER PT J AU Hick, SM Tran, CN Blair, RG Kaner, RB AF Hick, SM Tran, CN Blair, RG Kaner, RB TI Rapid solid state synthesis of lanthanide doped nitride phosphors. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Univ Calif Los Angeles, Dept Chem & Biochem, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Calif NanoSyst Inst, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. EM shick@chem.ucla.edu 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 MAR 13 PY 2005 VL 229 MA 587-INOR BP U1052 EP U1052 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177707585 ER PT J AU Hurst, JB Knappman, KA Gorican, D AF Hurst, JB Knappman, KA Gorican, D TI Synthesis and separation of boron nitride nanotubes. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 NASA, Glenn Res Ctr, Div Mat, Ceram Branch, Cleveland, OH 44135 USA. Union Univ, Dept Chem, Jackson, TN 38305 USA. EM Janet.B.Hurst@grc.nasa.gov; s200000@uu.edu NR 0 TC 0 Z9 0 U1 1 U2 3 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 MAR 13 PY 2005 VL 229 MA 1105-CHED BP U525 EP U525 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177703524 ER PT J AU Ilhan, F AF Ilhan, F TI Synthesis and optical properties of highly substituted anthracene bisimide derivatives SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Ohio Aerosp Inst, Polymers Branch, Div Mat, Cleveland, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44142 USA. EM ulvi.f.ilhan@grc.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 MAR 13 PY 2005 VL 229 MA 223-ORGN BP U359 EP U360 PN 2 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 008UQ UT WOS:000235066601328 ER PT J AU Kojiro, DR Mancinelli, R Martin, J Holland, PM Stimac, RM Kaye, WJ AF Kojiro, DR Mancinelli, R Martin, J Holland, PM Stimac, RM Kaye, WJ TI Mars geochemical instrument (MARGI): An instrument for the analysis of the martian surface and the search for evidence of life. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 NASA, Ames Res Ctr, Div Space Sci, Exobiol Branch, Moffett Field, CA 94035 USA. EM Daniel.R.Kojiro@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 MAR 13 PY 2005 VL 229 MA 231-ANYL BP U126 EP U126 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177700564 ER PT J AU Lamb, A Moore, MH AF Lamb, A Moore, MH TI Cosmic radiation effects on solid methane SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Emory & Henry Coll, Dept Chem, Emory, VA 24327 USA. NASA, Goddard Space Flight Ctr, Astrochem Branch, Greenbelt, MD 20771 USA. EM alamb@ehc.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 MAR 13 PY 2005 VL 229 MA 400-CHED BP U400 EP U400 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177702426 ER PT J AU Luther, GW Nuzzio, DB Taillefert, M Glazer, BT Kraiya, C Waite, T Tsang, J Janzen, C Drusche, G AF Luther, GW Nuzzio, DB Taillefert, M Glazer, BT Kraiya, C Waite, T Tsang, J Janzen, C Drusche, G TI Exploring the chemistry of diverse marine environments using in situ voltammetry. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Univ Delaware, Coll Marine Studies, Lewes, DE 19958 USA. Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Univ Hawaii, NASA, Astrobiol Inst, Honolulu, HI 96822 USA. Susquehanna Univ, Dept Chem, Selinsgrove, PA USA. Univ Vermont, Dept Geol, Burlington, VT 05405 USA. EM luther@udel.edu RI Luther, III, George/A-6384-2008 OI Luther, III, George/0000-0002-0780-885X 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 MAR 13 PY 2005 VL 229 MA 397-ANYL BP U152 EP U152 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177700728 ER PT J AU McCoy, AB Francisco, JS Fry, JL Mollner, AK Wennberg, PO Sanders, SP Okumura, M AF McCoy, AB Francisco, JS Fry, JL Mollner, AK Wennberg, PO Sanders, SP Okumura, M TI Internal hydrogen bonding and the overtone action spectrum of cis-cis HOONO: A twisted tale. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Ohio State Univ, Dept Chem, Columbus, OH 43210 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. CALTECH, Div Chem & Chem Engn, Arthur Amos Noyes Lab Chem Phys, Pasadena, CA 91125 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91125 USA. EM mccoy@chemistry.ohio-state.edu; mo@its.caltech.edu RI Wennberg, Paul/A-5460-2012 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 MAR 13 PY 2005 VL 229 MA 593-PHYS BP U794 EP U794 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 008UQ UT WOS:000235066603591 ER PT J AU Meyyappan, M AF Meyyappan, M TI Carbon nanotubes in composites. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM meyya@orbit.arc.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 MAR 13 PY 2005 VL 229 MA 283-PMSE BP U1147 EP U1147 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 008UQ UT WOS:000235066605283 ER PT J AU Mulchandani, A Myung, N Chen, W Bangar, M Ramnathan, K Yun, MH AF Mulchandani, A Myung, N Chen, W Bangar, M Ramnathan, K Yun, MH TI Individually addressable nanowires immunosensor array. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Univ Calif Riverside, Dept Environm Chem & Engn, Riverside, CA 92521 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. EM adani@engr.ucr.edu RI Mulchandani, Ashok/B-9692-2016 OI Mulchandani, Ashok/0000-0002-2831-4154 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 MAR 13 PY 2005 VL 229 MA 193-IEC BP U940 EP U940 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177706634 ER PT J AU Qu, LW Lin, Y Hill, D Zhou, B Wang, W Kitaygorodskiy, A Sun, XF Suarez, M Connell, JW Allard, LF Sun, YP AF Qu, LW Lin, Y Hill, D Zhou, B Wang, W Kitaygorodskiy, A Sun, XF Suarez, M Connell, JW Allard, LF Sun, YP TI Polyimide-functionalized carbon nanotubes for nanocomposite thin films. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Clemson Univ, Dept Chem, HOward L Hunter Chem Lab, Clemson, SC 29634 USA. NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23665 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. EM qliangw@CLEMSON.EDU; syaping@clemson.edu NR 0 TC 0 Z9 0 U1 1 U2 3 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 MAR 13 PY 2005 VL 229 MA 114-POLY BP U923 EP U923 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 008UQ UT WOS:000235066604114 ER PT J AU Ricco, AJ AF Ricco, AJ TI In-situ gene expression on nanosatellites (ISGEN): Autonomous genetic assay system to characterize biological consequences of space travel. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 NASA, Ames Res Ctr, Astrobion Program, Stanford, CA 94305 USA. EM ajricco@alum.mit.edu RI Ricco, Antonio/A-5273-2010 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 MAR 13 PY 2005 VL 229 MA 412-ANYL BP U155 EP U155 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177700743 ER PT J AU Southward, RE Thompson, DS Davis, LM Scott, JL Broadwater, MST Thompson, DW AF Southward, RE Thompson, DS Davis, LM Scott, JL Broadwater, MST Thompson, DW TI Macromolecular matrix mediated metallization of fluorinated and traditional polyimides yielding highly reflective silvered membranes at low metal concentrations. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 NASA, Adv Mat & Proc Branch, Hampton, VA 23681 USA. Coll William & Mary, Dept Chem, Williamsburg, VA 23185 USA. Coll William & Mary, Dept Biol, Williamsburg, VA 23185 USA. 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 MAR 13 PY 2005 VL 229 MA 250-PMSE BP U1142 EP U1142 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 008UQ UT WOS:000235066605250 ER PT J AU Thomson, DL Bryant, RG Keller, P Topping, CC AF Thomson, DL Bryant, RG Keller, P Topping, CC TI Position control of a viscoelastic liquid crystal elastomer actuator. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. Inst Curie, CNRS, Lab Physicochim Curie, UMR 168,Sect Rech, F-75231 Paris, France. EM d.l.thomsen@nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 3 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 MAR 13 PY 2005 VL 229 MA 530-POLY BP U984 EP U984 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 008UQ UT WOS:000235066604527 ER PT J AU Tyson, DS AF Tyson, DS TI Synthesis and chemosensory behavior of anthracene bisimide derivatives SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 Ohio Aerosp Inst, Div Mat, Polymers Branch, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. EM Daniel.S.Tyson@grc.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 MAR 13 PY 2005 VL 229 MA 222-ORGN BP U359 EP U359 PN 2 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 008UQ UT WOS:000235066601327 ER PT J AU Warren-Rhodes, KA Rhodes, KL Pointing, SB Ewing, S Lacap, DC Gomez-Silva, B Amundson, R Friedmann, EI McKay, CP AF Warren-Rhodes, KA Rhodes, KL Pointing, SB Ewing, S Lacap, DC Gomez-Silva, B Amundson, R Friedmann, EI McKay, CP TI Aridity-induced limit to photosynthesis and primary production in the Atacama Desert. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract CT 229th National Meeting of the American-Chemical-Society CY MAR 13-17, 2005 CL San Diego, CA SP Amer Chem Soc C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Hong Kong, Dept Ecol & Biodivers, Hong Kong, Hong Kong, Peoples R China. Univ Calif Berkeley, Dept Environm Sci Policy & Management, Ecosyst Sci Div, Berkeley, CA 94720 USA. Univ Antofagasta, Dept Biomed, Antofagasta, Chile. Univ Antofagasta, Inst Desierto, Antofagasta, Chile. RI Amundson, Ronald /E-2654-2015 NR 0 TC 0 Z9 0 U1 0 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 MAR 13 PY 2005 VL 229 MA 047-GEOC BP U889 EP U889 PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA 913TZ UT WOS:000228177706355 ER PT J AU Mizuno, T Kamae, T Ng, JST Tajima, H Mitchell, JW Streitmatter, R Fernholz, RC Groth, E Fukazawa, Y AF Mizuno, T Kamae, T Ng, JST Tajima, H Mitchell, JW Streitmatter, R Fernholz, RC Groth, E Fukazawa, Y TI Beam test of a prototype detector array for the PoGO astronomical hard X-ray/soft gamma-ray polarimeter SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE polarimetry; balloon; gamma-ray; Monte Carlo ID CRAB-NEBULA; EGS4 CODE; POLARIZATION; SCATTERING; EMISSION; PHOTON; IMPLEMENTATION; COMPTON; PHYSICS; PULSAR AB Polarization measurements in the X-ray and gamma-ray energy range can provide crucial information on massive compact objects such as black holes and neutron stars. The Polarized Gamma-ray Observer (PoGO) is a new balloon-borne instrument designed to measure polarization from astrophysical objects in the 30-100keV range, under development by an international collaboration with members from United States, Japan, Sweden and France. To examine PoGO's capability, a beam test of a simplified prototype detector array was conducted at the Argonne National Laboratory Advanced Photon Source. The detector array consisted of seven plastic scintillators, and was irradiated by polarized photon beams at 60, 73 and 83 keV. The data showed a clear polarization signal, with a measured modulation factor of 0.42 +/- 0.01. This was successfully reproduced at the 1.0% level by the computer simulation package Geant4 after modifications to its implementation of polarized Compton/Rayleigh scattering. Details of the beam test and the validation of the Geant4 simulations are presented. (c) 2004 Elsevier B.V. All rights reserved. C1 Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Princeton Univ, Princeton, NJ 08544 USA. Hiroshima Univ, Hiroshima 7398526, Japan. RP Mizuno, T (reprint author), Stanford Linear Accelerator Ctr, Menlo Pk, CA 94025 USA. EM mizuno@SLAC.Stanford.EDU NR 32 TC 32 Z9 32 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAR 11 PY 2005 VL 540 IS 1 BP 158 EP 168 DI 10.1016/j.nima.2004.11.009 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 909YL UT WOS:000227896500011 ER PT J AU Smelyanskiy, VN Luchinsky, DG Stefanovska, A McClintock, PVE AF Smelyanskiy, VN Luchinsky, DG Stefanovska, A McClintock, PVE TI Inference of a nonlinear stochastic model of the cardiorespiratory interaction SO PHYSICAL REVIEW LETTERS LA English DT Article ID RESPIRATORY SINUS ARRHYTHMIA; HEART-RATE; CARDIOVASCULAR-SYSTEM; VARIABILITY; HUMANS; MECHANISMS AB We reconstruct a nonlinear stochastic model of the cardiorespiratory interaction in terms of a set of polynomial basis functions representing the nonlinear force governing system oscillations. The strength and direction of coupling and noise intensity are simultaneously inferred from a univariate blood pressure signal. Our new inference technique does not require extensive global optimization, and it is applicable to a wide range of complex dynamical systems subject to noise. C1 NASA, Ames Res Ctr, Mission Crit Technol Inc, Moffett Field, CA 94035 USA. Univ Lancaster, Dept Phys, Lancaster LA1 4YB, England. Univ Ljubljana, Fac Elect Engn, Ljubljana 1000, Slovenia. RP Smelyanskiy, VN (reprint author), NASA, Ames Res Ctr, Mission Crit Technol Inc, MS 269-2, Moffett Field, CA 94035 USA. RI Luchinsky, Dmitry/N-4177-2014 NR 33 TC 41 Z9 41 U1 0 U2 9 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 MAR 11 PY 2005 VL 94 IS 9 AR 098101 DI 10.1103/PhysRevLett.94.098101 PG 4 WC Physics, Multidisciplinary SC Physics GA 905KC UT WOS:000227566000061 PM 15784004 ER PT J AU Arvidson, RE Poulet, F Bibring, JP Wolff, M Gendrin, A Morris, RV Freeman, JJ Langevin, Y Mangold, N Bellucci, G AF Arvidson, RE Poulet, F Bibring, JP Wolff, M Gendrin, A Morris, RV Freeman, JJ Langevin, Y Mangold, N Bellucci, G TI Spectral reflectance and morphologic correlations in eastern Terra Meridiani, Mars SO SCIENCE LA English DT Article ID OPPORTUNITY ROVER; PLANUM; SPECTROMETER; WATER AB The Mars Express Observatoire pour la Mineralogie, l'Eau, les Glaces, et l'Activite (OMEGA) hyperspectral image data covering eastern Terra Meridiani indicate the ubiquitous presence of molecular water in etched terrain materials that disconformabty overlie heavily cratered terrains and underlie the hematite-bearing plains explored by the Opportunity rover. Identification of crystalline water in kieserite (MgSO4.H2O) is linked to materials exposed in a valley and plateau to the north of hematite-bearing plains. The mineralogical similarities between the etched terrain deposits examined with OMEGA data and the layered rocks examined by Opportunity imply that the ancient aqueous environments inferred from analyses of the rover data extend over regional scales. C1 Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. Inst Astrophys Spatiale, F-91405 Orsay, France. Space Sci Inst, Boulder, CO 80301 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Ist Fis Spazio Interplanetario, Ist Nazl Astrofis, I-00133 Rome, Italy. RP Arvidson, RE (reprint author), Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. EM arvidson@wunder.wustl.edu OI Bellucci, Giancarlo/0000-0003-0867-8679 NR 24 TC 125 Z9 128 U1 3 U2 17 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD MAR 11 PY 2005 VL 307 IS 5715 BP 1591 EP 1594 DI 10.1126/science.1109509 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 906ED UT WOS:000227622400038 PM 15718425 ER PT J AU Rhoads, JE Panagia, N Windhorst, RA Malhotra, S Pirzkal, N Xu, C Strolger, LG Bergeron, LE Daddi, E Ferguson, H Gardner, JP Gronwall, C Haiman, Z Koekemoer, A Kummel, M Moustakas, LA Pasquali, A Riess, A Alighieri, SD Stiavelli, M Tsvetanov, Z Vernet, J Walsh, J Yan, HJ AF Rhoads, JE Panagia, N Windhorst, RA Malhotra, S Pirzkal, N Xu, C Strolger, LG Bergeron, LE Daddi, E Ferguson, H Gardner, JP Gronwall, C Haiman, Z Koekemoer, A Kummel, M Moustakas, LA Pasquali, A Riess, A Alighieri, SD Stiavelli, M Tsvetanov, Z Vernet, J Walsh, J Yan, HJ TI A redshift z approximate to 5.4 Ly alpha emitting galaxy with linear morphology in the GRAPES/Hubble Ultra Deep Field SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : formation; galaxies : high-redshift; galaxies : individual (UDF 5225); galaxies : interactions; galaxies : starburst ID HUBBLE-SPACE-TELESCOPE; LY-ALPHA EMITTERS; HOST GALAXY; SPECTROSCOPY; EMISSION; UNIVERSE; CAMERA AB We have discovered an extended Ly alpha plume ( UDF 5225) associated with a compact source at redshift z approximate to 5.4 in slitless spectroscopic data from the Grism ACS Program for Extragalactic Science ( GRAPES) project. The spatial extent of the emission is about 6 x 1.5 kpc (1" x 0."25). Combining our grism data and the broadband images from the Hubble Ultra Deep Field ( UDF) images, we find a Ly alpha line flux of similar to 2.2 x 10(-17) ergs cm(-2) s(-1) and surface brightness similar to 7 x 10(-17) ergs cm(-2) s(-1) arcsec(-2). The UDF images show diffuse continuum emission associated with UDF 5225, including three embedded knots. The morphology of UDF 5225 is highly suggestive of a galaxy in assembly. It is possible that the prominent Ly alpha emission from this object is due to an active nucleus, and that we are seeing the simultaneous growth through accretion of a galaxy and its central black hole. Follow- up observations at higher spectral resolution could test this hypothesis. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. European Space Agcy, ESTEC, Space Telescope Div, NL-2200 AG Noordwijk, Netherlands. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. European So Observ, D-85748 Garching, Germany. NASA, Astron & Solar Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Penn State Univ, Davey Lab 525, University Pk, PA 16802 USA. Columbia Univ, Dept Astron, Pupin Phys Labs 1328, New York, NY 10027 USA. Space Telescope European Coordinating Facil, D-85748 Garching, Germany. ETH Hoenggerberg, Inst Astron, CH-8093 Zurich, Switzerland. Osserv Astrofis Arcetri, I-50125 Florence, Italy. NASA Headquarters, Washington, DC 20546 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. RP Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. EM rhoads@stsci.edu RI Daddi, Emanuele/D-1649-2012; di Serego Alighieri, Sperello/E-4067-2010; OI Daddi, Emanuele/0000-0002-3331-9590; di Serego Alighieri, Sperello/0000-0001-8769-2692; Koekemoer, Anton/0000-0002-6610-2048 NR 27 TC 22 Z9 22 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD MAR 10 PY 2005 VL 621 IS 2 BP 582 EP 586 DI 10.1086/427622 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905CM UT WOS:000227545300003 ER PT J AU Homeier, NL Demarco, R Rosati, P Postman, M Blakeslee, JP Bouwens, RJ Bradley, LD Ford, HC Goto, T Gronwall, C Holden, B Jee, MJ Martel, AR Mei, S Menanteau, F Zirm, A Clampin, M Hartig, GF Illingworth, GD Ardila, DR Bartko, F Benitez, N Broadhurst, TJ Brown, RA Burrows, CJ Cheng, ES Cross, NJG Feldman, PD Franx, M Golimowski, DA Infante, L Kimble, RA Krist, JE Lesser, MP Meurer, GR Miley, GK Motta, V Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W AF Homeier, NL Demarco, R Rosati, P Postman, M Blakeslee, JP Bouwens, RJ Bradley, LD Ford, HC Goto, T Gronwall, C Holden, B Jee, MJ Martel, AR Mei, S Menanteau, F Zirm, A Clampin, M Hartig, GF Illingworth, GD Ardila, DR Bartko, F Benitez, N Broadhurst, TJ Brown, RA Burrows, CJ Cheng, ES Cross, NJG Feldman, PD Franx, M Golimowski, DA Infante, L Kimble, RA Krist, JE Lesser, MP Meurer, GR Miley, GK Motta, V Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W TI The transformation of cluster galaxies at intermediate redshift SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : clusters : general; galaxies : clusters : individual (Cl 0152-1357); galaxies : evolution; galaxies : high-redshift; galaxies : interactions ID DWARF ELLIPTIC GALAXIES; HUBBLE-SPACE-TELESCOPE; STAR-FORMATION RATES; PASSIVE SPIRAL GALAXIES; VIRGO CLUSTER; LENSING CLUSTER; ADVANCED CAMERA; O-II; INTRACLUSTER MEDIUM; DISK GALAXIES AB We combine imaging data from the Advanced Camera for Surveys ( ACS) with VLT/ FORS optical spectroscopy to study the properties of star- forming galaxies in the z = 0: 837 cluster Cl 0152 - 1357. We have morphological information for 24 star- forming cluster galaxies, which range in morphology from late- type and irregular to compact early- type galaxies. We find that while most star- forming galaxies have r(625) - i(775) colors bluer than 1.0, eight are in the red cluster sequence. Among the star- forming cluster population, we find five compact early- type galaxies that have properties consistent with their identification as progenitors of dwarf elliptical galaxies. The spatial distribution of the star- forming cluster members is nonuniform. We find none within R similar to 500 Mpc of the cluster center, which is highly suggestive of an intracluster medium interaction. We derive star formation rates from [ O II] lambda 3727 line fluxes and use these to compare the global star formation rate of Cl 0152 - 1357 to other clusters at low and intermediate redshifts. We find a tentative correlation between integrated star formation rates and T-X, in the sense that hotter clusters have lower integrated star formation rates. Additional data from clusters with low X- ray temperatures are needed to confirm this trend. We do not find a significant correlation with redshift, suggesting that evolution is either weak or absent between z = 0: 2 and 0.8. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. European So Observ, D-85748 Garching, Germany. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Leiden Observ, NL-2300 RA Leiden, Netherlands. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Bartko Sci & Technol, Brighton, CO 80602 USA. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Conceptual Analyt LLC, Glenn Dale, MD 20769 USA. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. WM Keck Observ, Kamuela, HI 96743 USA. RP Homeier, NL (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. RI White, Richard/A-8143-2012; Clampin, mark/D-2738-2012; Kimble, Randy/D-5317-2012; OI tran, hien/0000-0001-7548-6664; Menanteau, Felipe/0000-0002-1372-2534; Benitez, Narciso/0000-0002-0403-7455; Blakeslee, John/0000-0002-5213-3548 NR 81 TC 41 Z9 41 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 MAR 10 PY 2005 VL 621 IS 2 BP 651 EP 662 DI 10.1086/427549 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905CM UT WOS:000227545300009 ER PT J AU Bregman, J Temi, P AF Bregman, J Temi, P TI Variations of the mid-infrared emission spectrum in reflection nebulae SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared : ISM; ISM : lines and bands; ISM : molecules; reflection nebulae ID POLYCYCLIC AROMATIC-HYDROCARBONS; UNIDENTIFIED INFRARED-EMISSION; PAH MOLECULES; BANDS; NGC-1333; ABSORPTION; EXCITATION; EVOLUTION; GALAXIES; FEATURES AB Using spatial-spectral data cubes of reflection nebulae obtained by ISOCAM, we have observed a shift in the central wavelength of the 7.7 mu m band within several reflection nebulae. This band, composed of components at 7.85 and 7.65 mu m, shows a centroid shift from 7.75 mu m near the edge of the nebulae to 7.65 mu m toward the center of the nebulae as the shorter wavelength component becomes relatively stronger. The behavior of the 7.7 mu m band center can be explained by assuming either that anions are the origin of the 7.85 mu m band and cations the 7.65 mu m band, or that the band center wavelength depends on the chemical nature of the polycyclic aromatic hydrocarbons (PAHs). The ratio of the 11.3/ 7.7 mu m bands also changes with distance from the central star, first rising from the center toward the edge of the nebula, then falling at the largest distances from the star, consistent with the 11.3/7.7 mu m band ratio being controlled by the PAH ionization state. C1 NASA, Astrophys Branch, Ames Res Ctr, Moffett Field, CA 94035 USA. SETI Inst, Mountain View, CA 94043 USA. RP NASA, Astrophys Branch, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. NR 40 TC 42 Z9 42 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 MAR 10 PY 2005 VL 621 IS 2 BP 831 EP 838 DI 10.1086/427738 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905CM UT WOS:000227545300024 ER PT J AU Sandell, G Goss, WM Wright, M AF Sandell, G Goss, WM Wright, M TI Protostars and outflows in the NGC 7538 IRS 9 cloud core SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; ISM : individual (IRS 9, NGC 7538); ISM : molecules; radio lines : ISM; stars : formation; stars : pre-main sequence ID MASSIVE STAR-FORMATION; YOUNG STELLAR OBJECTS; SUBMILLIMETER CONTINUUM OBSERVATIONS; MOLECULAR CLOUDS; METHANOL MASERS; FORMING REGIONS; HII-REGIONS; PROTOSTELLAR COLLAPSE; DYNAMICAL COLLAPSE; MULTIPLE OUTFLOWS AB New high-resolution observations of HCO+ J = 1 --> 0, (HCN)-C-13 J = 1 --> 0, SO (2(2) --> 1(1)), and continuum with BIMA at 3.4 mm show that the NGC 7538 IRS 9 cloud core is a site of active, ongoing star formation. Our observations reveal at least three young bipolar molecular outflows, all similar to 10,000 - 20,000 yr old. IRS 9 drives a bipolar extreme high-velocity outflow observed nearly pole-on. South of IRS 9 we find a cold protostellar condensation with a size of similar to 14 '' x 6 '' and a mass of more than 250 M-.. This is the center of one of the outflows and shows deep redshifted self-absorption in HCO+, suggesting that there is a protostar embedded in the core, still in a phase of active accretion. This source is not detected in the far-infrared, suggesting that the luminosity is less than 10(4) L-.; yet, the mass of the outflow is similar to 60 M-.. The redshifted HCO+ self-absorption profiles observed toward the southern protostar and IRS 9 predict accretion rates of a few times 10(-4) to 10(-3) M-. yr(-1). Deep VLA continuum observations at 3.6 cm show that IRS 9 coincides with a faint thermal VLA source, but no other young star in the IRS 9 region has any detectable free-free emission at a level of similar to 60 mu Jy at 3.6 cm. The HCO+ abundance is significantly enhanced in the hot IRS 9 outflow. A direct comparison of mass estimates from HCO+ and CO for the well-characterized redshifted IRS 9 outflow predicts an HCO+ enhancement of more than a factor of 30, or [HCO+/H-2] >= 6 x 10(-8). C1 NASA, SOFIA USRA, Ames Res Ctr, Moffett Field, CA 94035 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Univ Calif Berkeley, Radio Astron Lab, Berkeley, CA 94720 USA. RP NASA, SOFIA USRA, Ames Res Ctr, MS N211-3, Moffett Field, CA 94035 USA. EM gsandell@mail.arc.nasa.gov NR 69 TC 19 Z9 19 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 MAR 10 PY 2005 VL 621 IS 2 BP 839 EP 852 DI 10.1086/427625 PN 1 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905CM UT WOS:000227545300025 ER PT J AU Butler, NR Sakamoto, T Suzuki, M Kawai, N Lamb, DQ Graziani, C Donaghy, TQ Dullighan, A Vanderspek, R Crew, GB Ford, P Ricker, G Atteia, JL Yoshida, A Shirasaki, Y Tamagawa, T Torii, K Matsuoka, M Fenimore, EE Galassi, M Doty, J Villasenor, J Prigozhin, G Jernigan, JG Barraud, C Boer, M Dezalay, JP Olive, JF Hurley, K Levine, A Martel, F Morgan, E Woosley, SE Cline, T Braga, J Manchanda, R Pizzichini, G AF Butler, NR Sakamoto, T Suzuki, M Kawai, N Lamb, DQ Graziani, C Donaghy, TQ Dullighan, A Vanderspek, R Crew, GB Ford, P Ricker, G Atteia, JL Yoshida, A Shirasaki, Y Tamagawa, T Torii, K Matsuoka, M Fenimore, EE Galassi, M Doty, J Villasenor, J Prigozhin, G Jernigan, JG Barraud, C Boer, M Dezalay, JP Olive, JF Hurley, K Levine, A Martel, F Morgan, E Woosley, SE Cline, T Braga, J Manchanda, R Pizzichini, G TI High-energy observations of XRF 030723: Evidence for an off-axis gamma-ray burst? SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : bursts; supernovae : general; X-rays : general ID PEAK ENERGY; SPECTRAL CHARACTERISTICS; LOW-LUMINOSITY; AFTERGLOWS; FLASH; GRB-031203; EMISSION; BEPPOSAX; MODELS; PERFORMANCE AB We report High Energy Transient Explorer 2 (HETE-2) Wide Field X-ray Monitor (WXM) and French Gamma Telescope observations of XRF 030723 along with observations of the XRF afterglow made using the 6.5 m Magellan Clay telescope and Chandra. The observed peak energy E-pk(obs) of the nu F-nu burst spectrum is found to lie within (or below) the WXM2 - 25 keV passband at 98.5% confidence, and no counts are detected above 30 keV. Our best-fit value is E-pk(obs) = 8.4(-3.4)(+3.5) keV. The ratio of X-ray to gamma-ray flux for the burst follows a correlation found for GRBs observed with HETE-2, and the duration of the burst is similar to that typical of long-duration GRBs. If we require that the burst isotropic equivalent energy E-iso and E-pk satisfy the relation discovered by Amati et al. (2002), a redshift of z = 0.38(-0.18)(+0.36) can be determined, in agreement with constraints determined from optical observations. We are able to fit the X-ray afterglow spectrum and to measure its temporal fade. Although the best-fit fade is shallower than the concurrent fade in the optical, the spectral similarity between the two bands indicates that the X-ray fade may actually trace the optical fade. If this is the case, the late-time rebrightening observed in the optical cannot be due to a supernova bump. We interpret the prompt and afterglow X-ray emission as arising from a jetted GRB observed off-axis and possibly viewed through a complex circumburst medium that is due to a progenitor wind. C1 MIT, Ctr Space Res, Cambridge, MA 02139 USA. Tokyo Inst Technol, Dept Phys, Meguro Ku, Tokyo 1528551, Japan. RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. Univ Chicago, Ctr Astron & Astrophys, Chicago, IL 60637 USA. Observ Midi Pyrenees, Astrophys Lab, F-31400 Toulouse, France. Aoyama Gakuin Univ, Dept Phys, Setagaya Ku, Tokyo 1578572, Japan. Natl Astron Observ, Tokyo 1818588, Japan. Osaka Univ, Grad Sch Sci, Dept Earth & Space Sci, Osaka 5600043, Japan. Natl Space Dev Agcy Japan, Tsukuba Space Ctr, Tsukuba, Ibaraki 3058505, Japan. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. UPS, CNRS, Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France. Univ Calif Santa Cruz, Dept Astron & Astrophys, Santa Cruz, CA 95064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Nacl Pesquisas Espaciais, BR-12227010 Sao Jose Dos Campos, Brazil. Tata Inst Fundamental Res, Dept Astron & Astrophys, Bombay 400005, Maharashtra, India. CNR, IASF, I-40129 Bologna, Italy. RP MIT, Ctr Space Res, 70 Vassar St, Cambridge, MA 02139 USA. OI Boer, Michel/0000-0001-9157-4349 NR 60 TC 20 Z9 20 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 MAR 10 PY 2005 VL 621 IS 2 BP 884 EP 893 DI 10.1086/427746 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905CM UT WOS:000227545300028 ER PT J AU Martin, S Drucker, R Kwok, R Holt, B AF Martin, S Drucker, R Kwok, R Holt, B TI Improvements in the estimates of ice thickness and production in the Chukchi Sea polynyas derived from AMSR-E SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID COASTAL POLYNYAS; SHELF; WATER AB For January-March 2003, we use 12.5-km resolution Advanced Microwave Scanning Radiometer (AMSR) data for the first time in a comparison with Synthetic Aperture Radar (SAR) and Special Sensor Microwave/Imager (SSM/I) data to study two Chukchi coast polynyas, one consisting of many, the other of only a few 25-km SSM/I pixels. Within these polynyas, the ice thicknesses are derived separately from the SMM/I 37-GHz and AMSR 36-GHz channels; the heat fluxes are derived by combining thicknesses with meteorological data. Comparison with ScanSAR data shows that for the large polynya, because AMSR provides better resolution of the surrounding coastline and first-year ice, the AMSR heat losses are greater than the SSM/I; for the small polynya, AMSR measures its variability even when its area is order of a single SSM/I pixel. This means that AMSR permits more accurate calculation of polynya heat losses, yielding the potential of improved estimates of Arctic polynya productivity. C1 Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Martin, S (reprint author), Univ Washington, Sch Oceanog, Box 357940, Seattle, WA 98195 USA. EM seelye@ocean.washington.edu RI Kwok, Ron/A-9762-2008; OI Kwok, Ron/0000-0003-4051-5896; Haberland, Christian/0000-0002-2981-7087 NR 9 TC 35 Z9 37 U1 0 U2 6 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 MAR 10 PY 2005 VL 32 IS 5 AR L05505 DI 10.1029/2004GL022013 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 906KZ UT WOS:000227641000007 ER PT J AU Goldstein, ME AF Goldstein, ME TI On identifying the true sources of aerodynamic sound SO JOURNAL OF FLUID MECHANICS LA English DT Article ID TURBULENCE AB A space-time filtering approach is used to divide an unbounded turbulent flow into its radiating and non-radiating components. The result is used to investigate the possibility of identifying the true Sources of the sound generated by this flow. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Goldstein, ME (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 20 TC 31 Z9 32 U1 0 U2 6 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD MAR 10 PY 2005 VL 526 BP 337 EP 347 DI 10.1017/S0022112004002885 PG 11 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 912MG UT WOS:000228082000013 ER PT J AU Marinova, MM McKay, CP Hashimoto, H AF Marinova, MM McKay, CP Hashimoto, H TI Radiative-convective model of warming Mars with artificial greenhouse gases SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID CLIMATE; ATMOSPHERES; CO2; CHLOROFLUOROCARBONS; INTENSITIES AB Artificial greenhouse gases could be used to warm Mars in order to make it habitable. Here we present new laboratory measurements of the thermal infrared absorption spectra of seven artificial greenhouse gases (CF4, C2F6, C3F8, SF6, CF3Cl, CF3Br, CF2Cl2) at concentrations from 10(-7) up to unity. We used a radiative-convective multilayer model to compute the warming caused by a mixture of the four fluorine-based greenhouse gases. The results show that for current Mars, C3F8 produces the largest warming: 0.56 K and 33.5 K for partial pressures of 10(-3) Pa and 1 Pa, respectively. Averaged over partial pressures from 0.01 to 1 Pa, the range of most interest for planetary ecosynthesis, CF4, C2F6, and SF6 were 17%, 49%, and 48% as effective as C3F8, respectively. The optimal mixture of the four fluorine-based greenhouse gases, taking into account the overlapping of their absorption bands, was 16% more effective than pure C3F8, averaged over the range 0.01 Pa to 1 Pa. Energy balance calculations suggest that the addition of similar to 0.2 Pa of the best greenhouse gases mixture or similar to 0.4 Pa of C3F8 would shift the equilibrium to the extent that CO2 would no longer be stable at the Martian poles and a runaway greenhouse effect would result. C1 Univ Tsukuba, Inst Engn Mech & Syst, Tsukuba, Ibaraki 3058573, Japan. CALTECH, Pasadena, CA 91125 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Univ Tsukuba, Inst Engn Mech & Syst, Tsukuba, Ibaraki 3058573, Japan. EM mmm@caltech.edu; cmckay@arc.nasa.gov; hhashi@kz.tsukuba.ac.jp NR 29 TC 3 Z9 3 U1 1 U2 7 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 MAR 10 PY 2005 VL 110 IS E3 AR E03002 DI 10.1029/2004JE002306 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 906LM UT WOS:000227642600002 ER PT J AU Richardson, MI Mischna, MA AF Richardson, MI Mischna, MA TI Long-term evolution of transient liquid water on Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID GENERAL-CIRCULATION MODEL; MARTIAN ATMOSPHERE; CHAOTIC OBLIQUITY; CLIMATE MODEL; THERMAL TIDES; NEAR-SURFACE; CO2; SUBSURFACE; DEPOSITS; ICE AB Liquid water is not currently stable on the surface of Mars; however, transient liquid water (ice melt) may occur if the surface temperature is between the melting and boiling points. Such conditions are met on Mars with current surface pressures and obliquity due to the large diurnal range of surface temperatures. This yields the potential for transient, nonequilibrium liquid water. A general circulation model is used to undertake an initial exploration of the variation of this "transient liquid water potential'' (TLWP) for different obliquities and over a range of increased pressures representing progressively earlier phases of Martian geological history. At higher obliquities and slightly higher surface pressures (< 50 mbar), TLWP conditions are met over a very large fraction of the planet. As the surface pressure is increased above about 50-100 mbar, however, increased atmospheric thermal blanketing reduces the diurnal surface temperature range, essentially eliminating the possibility of even transient liquid water. At high enough pressures, the mean temperature is sufficiently elevated to allow stable liquid water. Thus the potential for liquid water on Mars has not decreased monotonically over planetary history as the atmosphere was lost. Instead, a distinct minimum in TLWP ( the "dead zone'') will have occurred during the extended period for which pressures were in the middle range between about 0.1 and 1 bar. This has direct and restrictive implications for chemical weathering and life. The fundamental conclusion of this study is largely insensitive to invocation of brines and to more detailed treatment of atmospheric radiative processes. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RP Richardson, MI (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM mir@gps.caltech.edu NR 48 TC 43 Z9 43 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 MAR 10 PY 2005 VL 110 IS E3 AR E03003 DI 10.1029/2004JE002367 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 906LM UT WOS:000227642600003 ER PT J AU Porco, CC Baker, E Barbara, J Beurle, K Brahic, A Burns, JA Charnoz, S Cooper, N Dawson, DD Del Genio, AD Denk, T Dones, L Dyudina, U Evans, MW Fussner, S Giese, B Grazier, K Helfenstein, P Ingersoll, AP Jacobson, RA Johnson, TV McEwen, A Murray, CD Neukum, G Owen, WM Perry, J Roatsch, T Spitale, J Squyres, S Thomas, P Tiscareno, M Turtle, EP Vasavada, AR Veverka, J Wagner, R West, R AF Porco, CC Baker, E Barbara, J Beurle, K Brahic, A Burns, JA Charnoz, S Cooper, N Dawson, DD Del Genio, AD Denk, T Dones, L Dyudina, U Evans, MW Fussner, S Giese, B Grazier, K Helfenstein, P Ingersoll, AP Jacobson, RA Johnson, TV McEwen, A Murray, CD Neukum, G Owen, WM Perry, J Roatsch, T Spitale, J Squyres, S Thomas, P Tiscareno, M Turtle, EP Vasavada, AR Veverka, J Wagner, R West, R TI Imaging of Titan from the Cassini spacecraft SO NATURE LA English DT Article ID TROPOSPHERIC CLOUDS; GRAVITY-WAVES; ATMOSPHERE; SURFACE; IMAGES; VENUS; SUPERROTATION; SIMULATIONS; TEMPERATURE; OCCULTATION AB Titan, the largest moon of Saturn, is the only satellite in the Solar System with a substantial atmosphere. The atmosphere is poorly understood and obscures the surface, leading to intense speculation about Titan's nature. Here we present observations of Titan from the imaging science experiment onboard the Cassini spacecraft that address some of these issues. The images reveal intricate surface albedo features that suggest aeolian, tectonic and fluvial processes; they also show a few circular features that could be impact structures. These observations imply that substantial surface modification has occurred over Titan's history. We have not directly detected liquids on the surface to date. Convective clouds are found to be common near the south pole, and the motion of mid-latitude clouds consistently indicates eastward winds, from which we infer that the troposphere is rotating faster than the surface. A detached haze at an altitude of 500 km is 150 - 200 km higher than that observed by Voyager, and more tenuous haze layers are also resolved. C1 Space Sci Inst, Cassini Imaging Cent Lab Operat, Boulder, CO 80301 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Univ London, Queen Mary, Astron Unit, London E1 4NS, England. Univ Paris 07, CE Saclay, F-91191 Gif Sur Yvette, France. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Free Univ Berlin, Inst Geol Wissensch, D-12249 Berlin, Germany. SW Res Inst, Dept Space Sci, Boulder, CO 80302 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. German Aerosp Ctr, Inst Planetary Res, D-12489 Berlin, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Porco, CC (reprint author), Space Sci Inst, Cassini Imaging Cent Lab Operat, 4750 Walnut St,Suite 205, Boulder, CO 80301 USA. EM carolyn@ciclops.org RI Tiscareno, Matthew/D-6963-2011; Del Genio, Anthony/D-4663-2012; Turtle, Elizabeth/K-8673-2012 OI Del Genio, Anthony/0000-0001-7450-1359; Turtle, Elizabeth/0000-0003-1423-5751 NR 45 TC 253 Z9 255 U1 2 U2 34 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAR 10 PY 2005 VL 434 IS 7030 BP 159 EP 168 DI 10.1038/nature03436 PG 10 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 904JU UT WOS:000227494500034 PM 15758990 ER PT J AU Watson, KA Ghose, S Delozier, DM Smith, JG Connell, JW AF Watson, KA Ghose, S Delozier, DM Smith, JG Connell, JW TI Transparent, flexible, conductive carbon nanotube coatings for electrostatic charge mitigation SO POLYMER LA English DT Article DE low color polyimides; electrostatic charge mitigation; space durable polymers ID GROWTH; FILMS AB Low color, space environmentally durable polymeric films with sufficient electrical conductivity to mitigate electrostatic charge (ESC) build-up are needed for applications on advanced spacecraft, particularly on large, ultra-light weight space structures. For these applications, the films must exhibit electrical conductivity that can survive the folding and unfolding required for packaging and deployment. The work described herein consists of coating the surface of polymer films with a thin layer of single-walled carbon nanotubes (SWNTs). Surface resistivities in the range sufficient for ESC mitigation were achieved with minimal effects on the optical and thermo-optical properties of the films. Bending, folding or crumpling did not affect the surface resistivity of the coated films. The preparation and characterization of SWNT coated space durable polymer films are discussed. Published by Elsevier Ltd. C1 Natl Inst Aerosp, Hampton, VA 23666 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Natl Inst Aerosp, 144 Res Dr, Hampton, VA 23666 USA. EM k.a.watson@larc.nasa.gov NR 23 TC 44 Z9 45 U1 5 U2 15 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 EI 1873-2291 J9 POLYMER JI Polymer PD MAR 10 PY 2005 VL 46 IS 7 BP 2076 EP 2085 DI 10.1016/j.polymer.2004.12.057 PG 10 WC Polymer Science SC Polymer Science GA 906PP UT WOS:000227654500009 ER PT J AU Smith, JG Connell, JW Watson, KA Danehy, PM AF Smith, JG Connell, JW Watson, KA Danehy, PM TI Optical and thermo-optical properties of space durable polymer/carbon nanotube films: experimental results and empirical equations SO POLYMER LA English DT Article DE low color polyimides; carbon nanotubes; beer-lambert law ID WALLED CARBON NANOTUBES; FUNCTIONALIZATION AB The incorporation of purified high-pressure carbon monoxide prepared single-walled carbon nanotubes (HiPco SWNTs) into the bulk of space environmentally durable polymers at loading levels >= 0.05 wt% has afforded thin films with surface and volume resistivities sufficient for electrostatic charge mitigation. However, the optical transparency at 500 nm decreased and the solar absorptivity increased with increased SWNT loading. Besides showing a loading dependency, these properties were also dependent upon film thickness. The absorbance of the films at 500 nm as a function of SWNT loading and film thickness was determined to follow the classic Beer-Lambert law. Based on these results, a simple empirical relationship was derived to provide a predictive approximation of these properties. The molar absorptivity determined for the purified HiPco SWNTs dispersed in the polymer by this simple treatment was of the same order of magnitude to reported solution determined values for HiPco SWNTs. Crown Copyright (c) 2005 Published by Elsevier Ltd. All rights reserved. C1 NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Adv Sensing & Opt Measurement Branch, Hampton, VA 23681 USA. Natl Inst Aerosp, Hampton, VA 23666 USA. RP Smith, JG (reprint author), NASA, Langley Res Ctr, Adv Mat & Proc Branch, Mail Stop 226, Hampton, VA 23681 USA. EM joseph.g.smith@nasa.gov NR 21 TC 10 Z9 10 U1 0 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD MAR 10 PY 2005 VL 46 IS 7 BP 2276 EP 2284 DI 10.1016/j.polymer.2005.01.022 PG 9 WC Polymer Science SC Polymer Science GA 906PP UT WOS:000227654500030 ER PT J AU Mendillo, M Moore, L Clarke, J Mueller-Wodarg, I Kurth, WS Kaiser, ML AF Mendillo, M Moore, L Clarke, J Mueller-Wodarg, I Kurth, WS Kaiser, ML TI Effects of ring shadowing on the detection of electrostatic discharges at Saturn SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID IONOSPHERE; ATMOSPHERE; JUPITER; PLANETS; MODEL AB A long-standing discrepancy exists in determinations from observations and modeling of the diurnal variation of the peak electron density of Saturn's ionosphere. Using a new Saturn-Thermosphere-Ionosphere-Model (STIM), we examine the suggestion by Burns et al. (1983) that Saturn's rings shadow its ionosphere causing radio penetration "holes'', thereby allowing lightning-induced radio signals (Saturn electrostatic discharges, SEDs) to escape. This lessens the need to invoke globally enhanced loss processes to account for Voyager era observations of nighttime peak density (N-max) as low as 10(3) e/cm(3) from the SEDs. We find radio frequency "windows'' produced by ring shadowing that were narrow and confined to low latitudes during the Voyager era, but are now broadly distributed over northern mid-latitudes during the Cassini era. If lightning sources occur only at near-equatorial latitudes, then the far less frequent detection of SEDs by Cassini early in its mission would be consistent with the current ionospheric morphology. C1 Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Univ London Imperial Coll Sci Technol & Med, Dept Phys & Astron, London SW7, England. RP Mendillo, M (reprint author), Boston Univ, Ctr Space Phys, Boston, MA 02215 USA. EM mendillo@bu.edu RI Clarke, John/C-8644-2013; Mendillo, Michael /H-4397-2014; Mueller-Wodarg, Ingo/M-9945-2014; OI Mueller-Wodarg, Ingo/0000-0001-6308-7826; Moore, Luke/0000-0003-4481-9862; Kurth, William/0000-0002-5471-6202 NR 15 TC 13 Z9 13 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 MAR 9 PY 2005 VL 32 IS 5 AR L05107 DI 10.1029/2004GL021934 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 906KX UT WOS:000227640800005 ER PT J AU Salawitch, RJ Weisenstein, DK Kovalenko, LJ Sioris, CE Wennberg, PO Chance, K Ko, MKW McLinden, CA AF Salawitch, RJ Weisenstein, DK Kovalenko, LJ Sioris, CE Wennberg, PO Chance, K Ko, MKW McLinden, CA TI Sensitivity of ozone to bromine in the lower stratosphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BRO; TROPOSPHERE; BROMOFORM; BUDGET; GASES AB Measurements of BrO suggest that inorganic bromine (Br-y) at and above the tropopause is 4 to 8 ppt greater than assumed in models used in past ozone trend assessment studies. This additional bromine is likely carried to the stratosphere by short-lived biogenic compounds and their decomposition products, including tropospheric BrO. Including this additional bromine in an ozone trend simulation increases the computed ozone depletion over the past similar to 25 years, leading to better agreement between measured and modeled ozone trends. This additional Bry (assumed constant over time) causes more ozone depletion because associated BrO provides a reaction partner for ClO, which increases due to anthropogenic sources. Enhanced Bry causes photochemical loss of ozone below similar to 14 km to change from being controlled by HOx catalytic cycles (primarily HO2+ O-3) to a situation where loss by the BrO+HO2 cycle is also important. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91106 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Meteorol Serv Canada, Toronto, ON M3H 5T4, Canada. Atmospher & Environm Res Inc, Lexington, MA 02421 USA. RP Salawitch, RJ (reprint author), CALTECH, Jet Prop Lab, MS 183-601, Pasadena, CA 91106 USA. EM ross.j.salawitch@jpl.nasa.gov RI Salawitch, Ross/B-4605-2009; McLinden, Chris/A-7710-2010; Wennberg, Paul/A-5460-2012; Ko, Malcolm/D-5898-2015; OI Salawitch, Ross/0000-0001-8597-5832; McLinden, Chris/0000-0001-5054-1380; Chance, Kelly/0000-0002-7339-7577; Sioris, Christopher/0000-0003-1168-8755 NR 18 TC 129 Z9 130 U1 3 U2 31 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 9 PY 2005 VL 32 IS 5 AR L05811 DI 10.1029/2004GL021504 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 906KX UT WOS:000227640800002 ER PT J AU Kahn, RA Gaitley, BJ Martonchik, JV Diner, DJ Crean, KA Holben, B AF Kahn, RA Gaitley, BJ Martonchik, JV Diner, DJ Crean, KA Holben, B TI Multiangle Imaging Spectroradiometer (MISR) global aerosol optical depth validation based on 2 years of coincident Aerosol Robotic Network (AERONET) observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SKY RADIANCE MEASUREMENTS; DRY SEASON CAMPAIGN; SOUTHERN AFRICA; TROPOSPHERIC AEROSOLS; SAFARI 2000; THICKNESS; SUN; SENSITIVITY; RETRIEVAL; OCEAN AB Performance of the Multiangle Imaging Spectroradiometer (MISR) early postlaunch aerosol optical thickness (AOT) retrieval algorithm is assessed quantitatively over land and ocean by comparison with a 2-year measurement record of globally distributed AERONET Sun photometers. There are sufficient coincident observations to stratify the data set by season and expected aerosol type. In addition to reporting uncertainty envelopes, we identify trends and outliers, and investigate their likely causes, with the aim of refining algorithm performance. Overall, about 2/3 of the MISR-retrieved AOT values fall within [0.05 or 20% x AOT] of Aerosol Robotic Network (AERONET). More than a third are within [0.03 or 10% x AOT]. Correlation coefficients are highest for maritime stations (similar to 0.9), and lowest for dusty sites (more than similar to 0.7). Retrieved spectral slopes closely match Sun photometer values for Biomass burning and continental aerosol types. Detailed comparisons suggest that adding to the algorithm climatology more absorbing spherical particles, more realistic dust analogs, and a richer selection of multimodal aerosol mixtures would reduce the remaining discrepancies for MISR retrievals over land; in addition, refining instrument low-light-level calibration could reduce or eliminate a small but systematic offset in maritime AOT values. On the basis of cases for which current particle models are representative, a second-generation MISR aerosol retrieval algorithm incorporating these improvements could provide AOT accuracy unprecedented for a spaceborne technique. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Kahn, RA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM ralph.kahn@jpl.nasa.gov RI Kahn, Ralph/D-5371-2012 OI Kahn, Ralph/0000-0002-5234-6359 NR 39 TC 153 Z9 154 U1 1 U2 20 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 MAR 9 PY 2005 VL 110 IS D10 AR D10S04 DI 10.1029/2004JD004706 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 906LG UT WOS:000227641900001 ER PT J AU Zhang, JL Christopher, SA Remer, LA Kaufman, YJ AF Zhang, JL Christopher, SA Remer, LA Kaufman, YJ TI Shortwave aerosol radiative forcing over cloud-free oceans from Terra: 1. Angular models for aerosols SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID BIOMASS-BURNING AEROSOLS; ENERGY SYSTEM CERES; OPTICAL-PROPERTIES; SATELLITE; ATMOSPHERE; TOP; INSTRUMENT; BUDGET; MODIS AB Using multiple satellite instruments, we demonstrate a new empirical method for obtaining shortwave (SW) aerosol angular distribution models (ADMs) over cloud-free oceans. We use nearly a year's worth of multispectral Moderate Resolution Imaging Spectroradiometer (MODIS) data to obtain aerosol properties within a Clouds and Earth Radiant Energy System (CERES) footprint and Special Sensor Microwave Imager (SSM/I) data to obtain near surface wind speed. The new aerosol ADMs are built as functions of near-surface ocean wind speed and MODIS aerosol optical depth at 0.55 mu m (tau(0.55)). Among the new features are ADMs as a function of the ratio of fine mode to total aerosol optical depth (eta), which contains information on aerosol type, and the combination of the CERES rotation azimuth plane scan mode CERES data and MODIS aerosol products to characterize aerosol properties over glint regions. The instantaneous aerosol forcing efficiencies (SW flux per unit optical depth at tau(0.55)) are 80.5, 63.1, and 73.0 Wm(-2), derived using the Earth Radiation Budget Experiment (ERBE), Tropical Rainfall Measuring Mission (TRMM), and the current Terra ADMs, respectively. This study highlights the necessity for building empirical aerosol ADMs as a function of wind speed, tau(0.55) and eta, and gives examples of newly constructed aerosol ADMs over cloud-free oceans. We conclude that an overall uncertainty of 10% will be introduced in the derived SW aerosol direct forcing over cloud-free oceans if the ADMs are constructed without considering aerosol darkening effect over glint regions and aerosol brightening over nonglint regions (like ERBE ADMs) or the variations in aerosol properties (like TRMM ADMs). In a companion paper (Zhang et al., 2005), these new ADMs are used to calculate the shortwave aerosol radiative forcing over the global oceans. C1 Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35805 USA. NASA, Goddard Space Flight Ctr, Ctr Data, Greenbelt, MD 20771 USA. USN, Res Lab, Monterey, CA 93943 USA. RP Zhang, JL (reprint author), Univ Alabama, Dept Atmospher Sci, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM zhang@nrlmry.navy.mil RI Christopher, Sundar/E-6781-2011 NR 26 TC 33 Z9 33 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 9 PY 2005 VL 110 IS D10 AR D10S23 DI 10.1029/2004JD005008 PG 7 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 906LG UT WOS:000227641900003 ER PT J AU Zhang, JL Christopher, SA Remer, LA Kaufman, YJ AF Zhang, JL Christopher, SA Remer, LA Kaufman, YJ TI Shortwave aerosol radiative forcing over cloud-free oceans from Terra: 2. Seasonal and global distributions SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ENERGY SYSTEM INSTRUMENT; OPTICAL-PROPERTIES; SATELLITE; CERES; ATMOSPHERE; MODIS; TOP; RETRIEVALS; STRATEGIES; RADIANCES AB Using 10 months of collocated Clouds and the Earth's Radiant Energy System (CERES) scanner and Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol and cloud data from Terra, we provide estimates of the shortwave aerosol direct radiative forcing (SWARF) and its uncertainties over the cloud-free global oceans. Newly developed aerosol angular distribution models (ADMs) (Zhang et al., 2005), specifically for different sea surface conditions and aerosol types, are used for inverting the CERES observed radiances to shortwave fluxes while accounting for the effect of aerosol optical properties on the anisotropy of the top of atmosphere (TOA) shortwave radiation fields. The spatial and seasonal distributions of SWARF are presented, and the MODIS retrieved aerosol optical depth (tau(0.55)) and the independently derived SWARF show a high degree of correlation and can be estimated using the equation SWARF = 0.05-74.6 tau(0.55) + 18.2 tau(2)(0.55) W m(-2) (tau 0.55 < 0.8). The instantaneous TOA SWARF from Terra overpass time is -6.4 +/- 2.6 W m(-2) for cloud-free oceans. Accounting for sample biases and diurnal averaging, we estimate the SWARF over cloud-free oceans to be -5.3 +/- 1.7 W m(-2), consistent with previous studies. Our study is an independent measurement-based assessment of cloud-free aerosol radiative forcing that could be used as a validation tool for numerical modeling studies. C1 Univ Alabama, Dept Atmospher Sci, Huntsville, AL 35805 USA. NASA, Goddard Space Flight Ctr, Ctr Data, Greenbelt, MD 20771 USA. USN, Res Lab, Monterey, CA 93943 USA. RP Univ Alabama, Dept Atmospher Sci, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM zhang@nrlmry.navy.mil RI Christopher, Sundar/E-6781-2011 NR 32 TC 68 Z9 72 U1 1 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD MAR 9 PY 2005 VL 110 IS D10 AR D10S24 DI 10.1029/2004JD005009 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 906LG UT WOS:000227641900004 ER PT J AU McMillan, RA Howard, J Zaluzec, NJ Kagawa, HK Mogul, R Li, YF Paavola, CD Trent, JD AF McMillan, RA Howard, J Zaluzec, NJ Kagawa, HK Mogul, R Li, YF Paavola, CD Trent, JD TI A self-assembling protein template for constrained synthesis and patterning of nanoparticle arrays SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID NIXPD1-X ALLOY-FILMS; METALLIZATION; CU3AU(100); PALLADIUM; GROWTH C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP McMillan, RA (reprint author), 5AM Ventures, 3000 Sand Hill Rd, Menlo Pk, CA 94025 USA. EM amcmillan@5AMventures.com NR 21 TC 81 Z9 84 U1 1 U2 22 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 MAR 9 PY 2005 VL 127 IS 9 BP 2800 EP 2801 DI 10.1021/ja043827s PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 904ET UT WOS:000227479600003 PM 15740085 ER PT J AU Nguyen, P Ng, HT Meyyappan, M AF Nguyen, P Ng, HT Meyyappan, M TI Growth of individual vertical germanium nanowires SO ADVANCED MATERIALS LA English DT Article ID FIELD-EFFECT TRANSISTOR; OXIDE NANOWIRE AB Vertical germanium nanowires (Figure, inset) can be synthesized on doped and undoped germanium substrates either as high-density arrays or as individual nanowires. The nanowires have smooth surfaces and uniform diameters, and possess (111) lattice fringes with an interplanar distance of 3.26 angstrom (Figure). Such vertical nanostructures are ideal for fabrication of vertical nano-transistors, such as surround-gate or top-gate transistors, and could be incorporated into other three-dimensional architectures. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. RP Meyyappan, M (reprint author), NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM meyya@orbit.arc.nasa.gov NR 14 TC 72 Z9 73 U1 1 U2 22 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD MAR 8 PY 2005 VL 17 IS 5 BP 549 EP + DI 10.1002/adma.200400908 PG 6 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 907ZK UT WOS:000227756600009 ER PT J AU Meador, MAB Fabrizio, EF Ilhan, F Dass, A Zhang, GH Vassilaras, P Johnston, JC Leventis, N AF Meador, MAB Fabrizio, EF Ilhan, F Dass, A Zhang, GH Vassilaras, P Johnston, JC Leventis, N TI Cross-linking amine-modified silica aerogels with epoxies: Mechanically strong lightweight porous materials SO CHEMISTRY OF MATERIALS LA English DT Article ID HYBRID COMPOSITES; GEL; MONOLITHS; NETWORKS; KINETICS; SURFACE; SI-29; NMR AB The mesoporous surfaces of TMOS-derived silica aerogels have been modified with amines by copolymerization of TMOS with APTES. The amine sites have become anchors for cross-linking the nanoparticles of the skeletal backbone of the aerogel by attachment of di-, tri-, and tetra-functional epoxies. The resulting conformal coatings increase the density of the native aerogels by a factor of 2-3 but the strength of the resulting materials may increase by more than 2 orders of magnitude. Processing variables such as the amount of APTES used to make the gels, the epoxy type and concentration used for crosslinking. and the cross-linking temperature and time were varied according to a multivariable design-of-experiments (DOE) model. It was found that while elastic modulus follows a similar trend with density, maximum strength is attained neither at the maximum density nor at the highest concentration of -NH2 groups, suggesting surface saturation effects. Aerogels cross-linked with the trifunctional epoxide always show improved strength compared with aerogels cross-linked with the other two epoxides under identical conditions. Solid C-13 NMR studies show residual unreacted epoxides, which condense with one another by heating cross-linked aerogels at 150degreesC. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Univ Missouri, Rolla, MO 65401 USA. Ohio Aerosp Inst, Cleveland, OH 44142 USA. RP Leventis, N (reprint author), NASA, Glenn Res Ctr, 21000 Brookpk Rd, Cleveland, OH 44135 USA. RI Dass, Amal/A-2520-2011; Dass, Amala/H-4729-2012; OI Dass, Amala/0000-0001-6942-5451; Meador, Mary Ann/0000-0003-2513-7372 NR 26 TC 162 Z9 168 U1 12 U2 153 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD MAR 8 PY 2005 VL 17 IS 5 BP 1085 EP 1098 DI 10.1021/cm048063u PG 14 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 903JF UT WOS:000227421300025 ER PT J AU Larour, E Rignot, E Joughin, I Aubry, D AF Larour, E Rignot, E Joughin, I Aubry, D TI Rheology of the Ronne Ice Shelf, Antarctica, inferred from satellite radar interferometry data using an inverse control method SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MASS-BALANCE; FILCHNER; OCEAN; ELEVATION; DYNAMICS; SHEETS; STREAM AB The Antarctic Ice Sheet is surrounded by large floating ice shelves that spread under their own weight into the ocean. Ice shelf rigidity depends on ice temperature and fabrics, and is influenced by ice flow and the delicate balance between bottom and surface accumulation. Here, we use an inverse control method to infer the rigidity of the Ronne Ice Shelf that best matches observations of ice velocity from satellite radar interferometry. Ice rigidity, or flow law parameter B, is shown to vary between 300 and 900 kPa a(1/3). Ice is softer along the side margins due to frictional heating, and harder along the outflow of large glaciers, which advect cold continental ice. Melting at the bottom surface of the ice shelf increases its rigidity, while freezing decreases it. Accurate numerical modelling of ice shelf flow must account for this spatial variability in mechanical characteristics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Ecole Cent Paris, Lab Mecan Sols Struct & Mat, F-92295 Chatenay Malabry, France. RP Larour, E (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 200-227, Pasadena, CA 91109 USA. EM eric.larour@jpl.nasa.gov RI Joughin, Ian/A-2998-2008; Rignot, Eric/A-4560-2014; Aubry, Denis/M-7880-2014 OI Joughin, Ian/0000-0001-6229-679X; Rignot, Eric/0000-0002-3366-0481; NR 17 TC 39 Z9 39 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 8 PY 2005 VL 32 IS 5 AR L05503 DI 10.1029/2004GL021693 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 906KW UT WOS:000227640700001 ER PT J AU Bozzolo, G Noebe, RD Mosca, HO AF Bozzolo, G Noebe, RD Mosca, HO TI Site preference of ternary alloying additions to NiTi: Fe, Pt, Pd, Au, Al, Cu, Zr, and Hf SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE computer simulations; nickel; titanium; palladium; platinum; hafnium; zirconium; iron; aluminum; copper; gold; shape memory alloy; semi-empirical methods ID SHAPE-MEMORY ALLOYS; ATOM LOCATION; 3RD ELEMENT AB A technique for atomistic modeling of the site substitution behavior of Pd in NiTi [G. Bozzolo, R.D. Noebe, H.O. Mosca, Atomistic modeling of Pd site preference in Ni, J. Alloys Comp., doi: 10.1016/j.jallcom.2004.05.015] has been extended to examine the behavior of several other alloying additions, namely, Fe, Pt, Au, Al, Cu, Zr and Hf in this important shape memory alloy. It was found that all elements, to a varying degree, displayed absolute preference for available sites in the deficient sublattice. However, the energetics of the different substitutional schemes, coupled with large-scale simulations indicate that the general trend in all cases is for the ternary addition to want to form stronger ordered structures with Ti. (C) 2004 Elsevier B.V. All rights reserved. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. UAM, Comis Nacl Energia Atom, San Martin, Buenos Aires, Argentina. RP Bozzolo, G (reprint author), Ohio Aerosp Inst, 22800 Cedar Point Rd, Cleveland, OH 44142 USA. EM guillermo.h.bozzolo@grc.nasa.gov NR 17 TC 44 Z9 48 U1 8 U2 23 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD MAR 8 PY 2005 VL 389 IS 1-2 BP 80 EP 94 DI 10.1016/j.jallcom.2004.07.051 PG 15 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 901AL UT WOS:000227255300014 ER PT J AU Stolc, V Samanta, MP Tongprasit, W Marshall, WF AF Stolc, V Samanta, MP Tongprasit, W Marshall, WF TI Genome-wide transcriptional analysis of flagellar regeneration in Chlamydomonas reinhardtii identifies orthologs of ciliary disease genes SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE cilia; flagella; polycystic kidney disease; RNA transcription ID INTRAFLAGELLAR TRANSPORT; EXPRESSION; BIOGENESIS; PROTEINS; ELEGANS; COMPLEX; ARRAYS; BLAST AB The important role that cilia and flagella play in human disease creates an urgent need to identify genes involved in ciliary assembly and function. The strong and specific induction of flagellar-coding genes during flagellar regeneration in Chlamydomonas reinhardtii suggests that transcriptional profiling of such cells would reveal new flagella-related genes. We have conducted a genome-wide analysis of RNA transcript levels during flagellar regeneration in Chlamydomonas by using maskless photolithography method-produced DNA oligonucleotide microarrays with unique probe sequences for all exons of the 19,803 predicted genes. This analysis represents previously uncharacterized whole-genome transcriptional activity profiling study in this important model organism. Analysis of strongly induced genes reveals a large set of known flagellar components and also identifies a number of important disease-related proteins as being involved with cilia and flagella, including the zebrafish polycystic kidney genes Qilin, Reptin, and Pontin, as well as the testis-expressed tubby-like protein TULP2. C1 NASA, Genome Res Facil, Ames Res Ctr, Moffett Field, CA 94035 USA. Yale Univ, Dept Mol Cellular & Dev Biol, New Haven, CT 06520 USA. NASA, Eloret Corp, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Calif San Francisco, Dept Biochem & Biophys, San Francisco, CA 94143 USA. Systemix Inst, Cupertino, CA 95014 USA. RP Stolc, V (reprint author), NASA, Genome Res Facil, Ames Res Ctr, Moffett Field, CA 94035 USA. EM vstolc@mail.arc.nasa.gov; wmarshall@biochem.ucsf.edu NR 25 TC 128 Z9 132 U1 1 U2 63 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD MAR 8 PY 2005 VL 102 IS 10 BP 3703 EP 3707 DI 10.1073/pnas.0408358102 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 904XY UT WOS:000227533100034 PM 15738400 ER PT J AU Li, JV Yang, RQ Hill, CJ Chuang, SL AF Li, JV Yang, RQ Hill, CJ Chuang, SL TI Interband cascade detectors with room temperature photovoltaic operation SO APPLIED PHYSICS LETTERS LA English DT Article ID QUANTUM-WELLS; LASERS AB We investigated mid-infrared interband cascade laser structures as photodetectors, which are sensitive to normal incidence and operate in photovoltaic mode at room temperature. The proposed operation principle of these interband cascade detectors is based on the unique combination of interband photoexcitation and the much faster intersubband relaxation as well as interband tunneling recombination, which allows for the efficient collection of the photoexcited carriers. Peak responsivity and detectivity of 21 mA/W and 7.1 X 10(8) cm Hz(1/2) /W at lambda=4.0 mu m are obtained for a device with cutoff wavelength of 4.4 mu m. Peak responsivity and detectivity of 46 mA/W and 1.4 X 10(9) cm Hz(1/2) /W at lambda=3.0 mu m are obtained for another device with cutoff wavelength of 3.3 mu m. These detectors exhibit low noise (4.8 X 10(-13) A/HZ(1/2)) and a large product of the differential resistance and active area (19 ohm cm(2)) at room temperature. (c) 2005 American Institute of Physics. C1 Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Li, JV (reprint author), Univ Illinois, Dept Elect & Comp Engn, 1406 W Green St, Urbana, IL 61801 USA. EM rui.q.yang@jpl.nasa.gov; s-chuang@uiuc.edu RI Li, Jian/B-1627-2016 NR 9 TC 29 Z9 30 U1 0 U2 6 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 MAR 7 PY 2005 VL 86 IS 10 AR 101102 DI 10.1063/1.1875758 PG 3 WC Physics, Applied SC Physics GA 911YQ UT WOS:000228044700002 ER PT J AU Svendsen, SH Larsen, N Knudsen, B Eckermann, SD Browell, EV AF Svendsen, SH Larsen, N Knudsen, B Eckermann, SD Browell, EV TI Influence of mountain waves and NAT nucleation mechanisms on polar stratospheric cloud formation at local and synoptic scales during the 1999-2000 Arctic winter SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID SOLID PARTICLE FORMATION; NITRIC-ACID TRIHYDRATE; LIDAR OBSERVATIONS; OZONE; DENITRIFICATION; TEMPERATURES; CLIMATOLOGY; AEROSOL; PSCS AB A scheme for introducing mountain wave- induced temperature pertubations in a microphysical PSC model has been developed. A data set of temperature fluctuations attributable to mountain waves as computed by the Mountain Wave Forecast Model (MWFM-2) has been used for the study. The PSC model has variable microphysics, enabling different nucleation mechanisms for nitric acid trihydrate, NAT, to be employed. In particular, the difference between the formation of NAT and ice particles in a scenario where NAT formation is not dependent on preexisting ice particles, allowing NAT to form at temperatures above the ice frost point, T-ice, and a scenario, where NAT nucleation is dependent on preexisting ice particles, is examined. The performance of the microphysical model in the different microphysical scenarios and a number of temperature scenarios with and without the influence of mountain waves is tested through comparisons with lidar measurements of PSCs made from the NASA DC-8 on 23 and 25 January during the SOLVE/THESEO 2000 campaign in the 1999-2000 winter and the effect of mountain waves on local PSC production is evaluated in the different microphysical scenarios. Mountain waves are seen to have a pronounced effect on the amount of ice particles formed in the simulations. Quantitative comparisons of the amount of solids seen in the observations and the amount of solids produced in the simulations show the best correspondence when NAT formation is allowed to take place at temperatures above Tice. Mountain wave-induced temperature fluctuations are introduced in vortex-covering model runs, extending the full 1999-2000 winter season, and the effect of mountain waves on large-scale PSC production is estimated in the different microphysical scenarios. It is seen that regardless of the choice of microphysics ice particles only form as a consequence of mountain waves whereas NAT particles form readily as a consequence of the synoptic conditions alone if NAT nucleation above T-ice is included in the simulations. Regardless of the choice of microphysics, the inclusion of mountain waves increases the amount of NAT particles by as much as 10%. For a given temperature scenario the choice of NAT nucleation mechanism may alter the amount of NAT substantially; three-fold increases are easily found when switching from the scenario which requires preexisting ice particles in order for NAT to form to the scenario where NAT forms independently of ice. C1 Danish Meteorol Inst, Copenhagen, Denmark. USN, Res Lab, Washington, DC 20375 USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Danish Meteorol Inst, Copenhagen, Denmark. EM shs@dmi.dk RI Larsen, Niels/G-3145-2014 NR 40 TC 8 Z9 8 U1 0 U2 2 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 MAR 7 PY 2005 VL 5 BP 739 EP 753 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 904GZ UT WOS:000227485400001 ER PT J AU Smith, SM O'Brien, KO Abrams, SA Wastney, ME Zwart, SR Davis-Street, JE AF Smith, SM O'Brien, KO Abrams, SA Wastney, ME Zwart, SR Davis-Street, JE TI Biological and within-subject variability of calcium kinetics and biochemical markers of bone turnover SO FASEB JOURNAL LA English DT Meeting Abstract CT Experimental Biology 2005 Meeting/35th International Congress of Physiological Sciences CY MAR 31-APR 06, 2005 CL San Diego, CA SP Amer Assoc Anatomists, Amer Assoc Immunologists, Amer Physiol Soc, Amer Soc Biochem & Mol Biol, Amer Soc Invest Pathol, Amer Soc Nutr Sci, Amer Soc Pharmacol & Exptl Therapeut, Int Union Physiol Sci C1 NASA, Human Adaptat & Countermeasures Off, Johnson Space Ctr, Houston, TX 77058 USA. Johns Hopkins Univ, Baltimore, MD 21205 USA. Baylor Coll Med, Childrens Nutr Res Ctr, Houston, TX 77030 USA. Metab Modeling Serv Ltd, Hamilton, New Zealand. Enterprise Advis Serv Inc, Houston, TX 77058 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 7 PY 2005 VL 19 IS 5 SU S BP A1345 EP A1345 PN 2 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 905ZS UT WOS:000227610902401 ER PT J AU Wiemann, JM Ueno, T Leek, B Yost, WT Schwartz, A Hargens, A AF Wiemann, JM Ueno, T Leek, B Yost, WT Schwartz, A Hargens, A TI Noninvasive measurements of intramuscular pressure using ultrasound in a model compartment syndrome SO FASEB JOURNAL LA English DT Meeting Abstract CT Experimental Biology 2005 Meeting/35th International Congress of Physiological Sciences CY MAR 31-APR 06, 2005 CL San Diego, CA SP Amer Assoc Anatomists, Amer Assoc Immunologists, Amer Physiol Soc, Amer Soc Biochem & Mol Biol, Amer Soc Invest Pathol, Amer Soc Nutr Sci, Amer Soc Pharmacol & Exptl Therapeut, Int Union Physiol Sci C1 Univ Calif San Diego, Dept Orthopaed Surg, San Diego, CA 92103 USA. NASA, Langley Res Ctr, Nondestruct Evaluat Sci Branch, Hampton, VA 23681 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 7 PY 2005 VL 19 IS 5 SU S BP A1123 EP A1123 PN 2 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 905ZS UT WOS:000227610901032 ER PT J AU Zwart, SR Hargens, AR Smith, SM AF Zwart, SR Hargens, AR Smith, SM TI The ratios of dietary animal protein or vegetable protein to potassium intake are differentially correlated with urinary calcium excretion in female bed rest subjects SO FASEB JOURNAL LA English DT Meeting Abstract CT Experimental Biology 2005 Meeting/35th International Congress of Physiological Sciences CY MAR 31-APR 06, 2005 CL San Diego, CA SP Amer Assoc Anatomists, Amer Assoc Immunologists, Amer Physiol Soc, Amer Soc Biochem & Mol Biol, Amer Soc Invest Pathol, Amer Soc Nutr Sci, Amer Soc Pharmacol & Exptl Therapeut, Int Union Physiol Sci C1 NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Off, Houston, TX 77058 USA. Univ Calif San Diego, Dept Orthopaed, San Diego, CA 92103 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 7 PY 2005 VL 19 IS 5 SU S BP A1463 EP A1463 PN 2 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 905ZS UT WOS:000227610903293 ER PT J AU Gurzadyan, VC Ade, PAR de Bernardis, P Bianco, CL Bock, JJ Boscaleri, A Crill, BP De Troia, G Hivon, E Hristov, VV Kashin, AL Kuloghlian, H Masi, S Mauskopf, PD Montroy, T Natoli, P Pascale, E Piacentini, F Polenta, G Yegorian, G AF Gurzadyan, VC Ade, PAR de Bernardis, P Bianco, CL Bock, JJ Boscaleri, A Crill, BP De Troia, G Hivon, E Hristov, VV Kashin, AL Kuloghlian, H Masi, S Mauskopf, PD Montroy, T Natoli, P Pascale, E Piacentini, F Polenta, G Yegorian, G TI Ellipticity of large spots in CMB anisotropy maps SO MODERN PHYSICS LETTERS A LA English DT Article DE cosmology; cosmic background radiation ID MICROWAVE BACKGROUND-RADIATION; ANGULAR POWER SPECTRUM; MULTIPLE PEAKS; BOOMERANG; CURVATURE; TOPOLOGY; UNIVERSE; COSMOLOGY; SPACE AB We have measured the ellipticity of several degree scale anisotropies in the BOOMERanG maps of the Cosmic Microwave Background (CMB) at 150 GHz. The average ellipticity is around 2.6-2.7. The biases of the estimator of the ellipticity and for the noise are small in this case. Large spot elongation had been detected also for COBE-DMR and WMAP maps. If this effect is due to geodesic mixing, it would indicate a non-precisely zero curvature of the Universe which is among the discussed reasons of the WMAP low multipole anomaly. C1 Yerevan Phys Inst, Yerevan 375036, Armenia. Univ Roma La Sapienza, Dipartimento Fis, ICRA, I-00185 Rome, Italy. Dept Phys & Astron, Cardiff, Wales. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. JPL, Pasadena, CA USA. CNR, IROE, Florence, Italy. CALTECH, Pasadena, CA USA. IPAC, Pasadena, CA USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Univ Roma Tor Vergata, Dipartimento Fis, I-00173 Rome, Italy. RP Gurzadyan, VC (reprint author), Yerevan Phys Inst, Yerevan 375036, Armenia. EM gurzadya@icra.it 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; Polenta, Gianluca/0000-0003-4067-9196; Hivon, Eric/0000-0003-1880-2733 NR 29 TC 6 Z9 6 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-7323 J9 MOD PHYS LETT A JI Mod. Phys. Lett. A PD MAR 7 PY 2005 VL 20 IS 7 BP 491 EP 498 DI 10.1142/S0217732305016658 PG 8 WC Physics, Nuclear; Physics, Particles & Fields; Physics, Mathematical SC Physics GA 913OL UT WOS:000228162600002 ER PT J AU Gianelli, SM Carlson, BE Lacis, AA AF Gianelli, SM Carlson, BE Lacis, AA TI Aerosol retrievals using rotating shadowband spectroradiometer data SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ABSORPTION CROSS-SECTIONS; SENSING REFERENCE DATA; 231-794 NM RANGE; ATMOSPHERIC AEROSOLS; OPTICAL-PROPERTIES; TRACE GASES; PART I; RADIOMETER; INSTRUMENT; SCATTERING AB The rotating shadowband spectroradiometer (RSS) is a high-resolution device that measures the total, direct, and diffuse intensity of sunlight at 1016 different wavelengths. RSS data can be used to retrieve gas amounts and aerosol properties as well as to assess the accuracy of retrievals using data from lower-spectral resolution instruments, such as the multifilter rotating shadowband radiometer (MFRSR). An algorithm to retrieve aerosol and gas amounts and the aerosol size distribution from RSS data, using the full resolution and using selected wavelengths, has been developed (Gianelli, 2004). The results of the retrievals, applied to RSS data from the southern Great Plains (SGP) site, indicate a number of things about the aerosol size distribution and our ability to retrieve aerosol information accurately. First, we show that the aerosol size distribution at SGP is at least bimodal. The notion that a more complex size distribution can be modeled with an appropriately selected monomodal distribution produces an unacceptable fit to the data once the separation of aerosol extinction from nitrogen dioxide absorption at short wavelengths is taken into consideration. Second, we find that the amount of retrievable aerosol information is limited by the wavelength range of the data. This is exemplified by the indeterminacy of the coarse-mode effective radius and the interdependence in the retrievals of the fine-mode effective radius and effective variance. Third, when the fine-mode effective variance is constrained, an annual cycle in fine-mode effective radius values emerges from the retrieval results, with a maximum in March and a minimum in September. Conceivably, changes in the effective variance could influence the observed pattern as well. The large margin of error in the coarse-mode effective radius leads to relatively small error bars for the coarse- and fine-mode optical depths, the fine-mode effective radius, and ozone, except on those days when the coarse- mode optical depth is high. Examining the retrieval results for different wavelength combinations of five RSS channels allows us to investigate whether or not the MFRSR channels are optimized to retrieve aerosol information or if a different filter set would increase the robustness of the retrievals. We show that replacing the 670 nm channel with one at either 375 or 1034 nm improves the retrieval accuracy. In particular, retrievals with the 1034 nm channel very closely reproduce the full RSS retrieval results, provided that the NO2 column amount can be determined by other means. The precision of the retrieved values of the fine-mode effective radius is shown to be strongly sensitive to the precision of measured NO2 amounts; a margin of error in column NO2 of 0.3 Dobson units results in a corresponding margin of error of 0.04 mm in the fine-mode effective radius. This confirms that aerosol sizes cannot be inferred accurately from optical depth spectra alone if either the amount of NO2 above a site is unknown or an inaccurate value is assumed. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Appl Math, New York, NY USA. RP Gianelli, SM (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM sgianell@kdist.giss.nasa.gov RI Lacis, Andrew/D-4658-2012; Carlson, Barbara/D-8319-2012 NR 27 TC 3 Z9 3 U1 1 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 MAR 5 PY 2005 VL 110 IS D5 AR D05203 DI 10.1029/2004JD005329 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 905EL UT WOS:000227550600004 ER PT J AU Abulchalav, IK Wineski, LE Silvestrov, NA von Deutsch, DA AF Abulchalav, IK Wineski, LE Silvestrov, NA von Deutsch, DA TI B2-adrenoceptor signal transduction and HO-1 activity in skeletal muscle SO FASEB JOURNAL LA English DT Meeting Abstract CT Experimental Biology 2005 Meeting/35th International Congress of Physiological Sciences CY MAR 31-APR 06, 2005 CL San Diego, CA SP Amer Assoc Anatomists, Amer Assoc Immunol, Amer Phtsiol Soc & Int Union Physiol Sci, Amer Soc Biochem & Mole Biol, Amer Soc Investigat Pathol, Amer Soc Nutr Sci, Amer Soc Pharmacol & Exptl Therapeut C1 Philadelphia Univ, Amman, Jordan. Morehouse Sch Med, NASA, Atlanta, GA 30310 USA. Morehouse Sch Med, Clin Res Ctr, Atlanta, GA 30310 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 4 PY 2005 VL 19 IS 4 SU S BP A528 EP A528 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 905ZQ UT WOS:000227610703517 ER PT J AU Baer, LA Ronca, AE Shaughnessey, R Foushee, R AF Baer, LA Ronca, AE Shaughnessey, R Foushee, R TI Improved reproductive success of Bobwhite (Colinus virginianus) quail embryos relative to Japanese (Coturnix coturnix japonica) quail embryos reared during 2-g centrifugation SO FASEB JOURNAL LA English DT Meeting Abstract CT Experimental Biology 2005 Meeting/35th International Congress of Physiological Sciences CY MAR 31-APR 06, 2005 CL San Diego, CA SP Amer Assoc Anatomists, Amer Assoc Immunol, Amer Phtsiol Soc & Int Union Physiol Sci, Amer Soc Biochem & Mole Biol, Amer Soc Investigat Pathol, Amer Soc Nutr Sci, Amer Soc Pharmacol & Exptl Therapeut C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Wake Forest Univ, Sch Med, Winston Salem, NC 27157 USA. Univ Alabama, Dept Psychol, Huntsville, AL 35899 USA. Fontbonne Univ, Dept Social Sci, St Louis, MO 63105 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 4 PY 2005 VL 19 IS 4 SU S BP A670 EP A670 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 905ZQ UT WOS:000227610704559 ER PT J AU Liang, MTC Bassin, SL Wong, ND Arnaud, SB Braun, WA Dutto, D Cooper, D AF Liang, MTC Bassin, SL Wong, ND Arnaud, SB Braun, WA Dutto, D Cooper, D TI Effects of six-month high-frequency impact-loaded aerobic versus strength training on bone health in premenopausal women SO FASEB JOURNAL LA English DT Meeting Abstract CT Experimental Biology 2005 Meeting/35th International Congress of Physiological Sciences CY MAR 31-APR 06, 2005 CL San Diego, CA SP Amer Assoc Anatomists, Amer Assoc Immunol, Amer Phtsiol Soc & Int Union Physiol Sci, Amer Soc Biochem & Mole Biol, Amer Soc Investigat Pathol, Amer Soc Nutr Sci, Amer Soc Pharmacol & Exptl Therapeut C1 Calif State Polytech Univ Pomona, Pomona, CA 91768 USA. GCRC, Irvine, CA 92697 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Shippensburg Univ, Shippensburg, PA 17257 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 4 PY 2005 VL 19 IS 4 SU S BP A669 EP A669 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 905ZQ UT WOS:000227610704553 ER PT J AU Ronca, AE Baer, LA Wade, CE AF Ronca, AE Baer, LA Wade, CE TI Prenatal hypergravity exposure: Evidence for developmental programming SO FASEB JOURNAL LA English DT Meeting Abstract CT Experimental Biology 2005 Meeting/35th International Congress of Physiological Sciences CY MAR 31-APR 06, 2005 CL San Diego, CA SP Amer Assoc Anatomists, Amer Assoc Immunol, Amer Phtsiol Soc & Int Union Physiol Sci, Amer Soc Biochem & Mole Biol, Amer Soc Investigat Pathol, Amer Soc Nutr Sci, Amer Soc Pharmacol & Exptl Therapeut C1 Wake Forest Univ, Sch Med, Winston Salem, NC 27101 USA. NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA. USA, Inst Surg Res, Ft Sam Houston, TX 78234 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 4 PY 2005 VL 19 IS 4 SU S BP A665 EP A665 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 905ZQ UT WOS:000227610704538 ER PT J AU Tou, J Brown, M Foley, A Yuan, Y Buff, P Wade, C Arnaud, S AF Tou, J Brown, M Foley, A Yuan, Y Buff, P Wade, C Arnaud, S TI Hindlimb unloading and reloading on long bones in intact versus ovariectomized rats SO FASEB JOURNAL LA English DT Meeting Abstract CT Experimental Biology 2005 Meeting/35th International Congress of Physiological Sciences CY MAR 31-APR 06, 2005 CL San Diego, CA SP Amer Assoc Anatomists, Amer Assoc Immunol, Amer Phtsiol Soc & Int Union Physiol Sci, Amer Soc Biochem & Mole Biol, Amer Soc Investigat Pathol, Amer Soc Nutr Sci, Amer Soc Pharmacol & Exptl Therapeut C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Missouri, Ctr Gen Physiol, Columbia, MO 65211 USA. Ryerson Univ, Toronto, ON M5B 2K3, Canada. USA, Inst Surg Res, Ft Sam Houston, TX 78234 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 4 PY 2005 VL 19 IS 4 SU S BP A197 EP A197 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 905ZQ UT WOS:000227610701271 ER PT J AU von Deutsch, DA AF von Deutsch, DA TI B2-adrenoceptor signal transduction and oxidative stress in human retinal cells SO FASEB JOURNAL LA English DT Meeting Abstract CT Experimental Biology 2005 Meeting/35th International Congress of Physiological Sciences CY MAR 31-APR 06, 2005 CL San Diego, CA SP Amer Assoc Anatomists, Amer Assoc Immunol, Amer Phtsiol Soc & Int Union Physiol Sci, Amer Soc Biochem & Mole Biol, Amer Soc Investigat Pathol, Amer Soc Nutr Sci, Amer Soc Pharmacol & Exptl Therapeut C1 Morehouse Sch Med, NASA, Space Med & Life Sci Res Ctr, Atlanta, GA 30310 USA. Morehouse Sch Med, Dept Pharmacol & Toxicol, Atlanta, GA 30310 USA. Morehouse Sch Med, MBRS Program, Atlanta, GA 30310 USA. Morehouse Sch Med, Clin Res Ctr, Atlanta, GA 30310 USA. Philadelphia Univ, Fac Sci, Amman 19392, Jordan. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 4 PY 2005 VL 19 IS 4 SU S BP A528 EP A528 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 905ZQ UT WOS:000227610703518 ER PT J AU Wade, C Baer, L Hsu, O McCue, R AF Wade, C Baer, L Hsu, O McCue, R TI Responses to hemorrhagic hypovolemia in hindlimb suspended (HLS) rats SO FASEB JOURNAL LA English DT Meeting Abstract CT Experimental Biology 2005 Meeting/35th International Congress of Physiological Sciences CY MAR 31-APR 06, 2005 CL San Diego, CA SP Amer Assoc Anatomists, Amer Assoc Immunol, Amer Phtsiol Soc & Int Union Physiol Sci, Amer Soc Biochem & Mole Biol, Amer Soc Investigat Pathol, Amer Soc Nutr Sci, Amer Soc Pharmacol & Exptl Therapeut C1 USA, Inst Surg Res, San Antonio, TX 78234 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 4 PY 2005 VL 19 IS 4 SU S BP A667 EP A667 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 905ZQ UT WOS:000227610704545 ER PT J AU Zakrzewska, EI Lintault, L Maple, R Baer, L Ronca, A Wade, C Plaut, K AF Zakrzewska, EI Lintault, L Maple, R Baer, L Ronca, A Wade, C Plaut, K TI Effects of 2 x gravity (2-g) on prolactin receptor expression in adipose tissue of periparturient rats SO FASEB JOURNAL LA English DT Meeting Abstract CT Experimental Biology 2005 Meeting/35th International Congress of Physiological Sciences CY MAR 31-APR 06, 2005 CL San Diego, CA SP Amer Assoc Anatomists, Amer Assoc Immunol, Amer Phtsiol Soc & Int Union Physiol Sci, Amer Soc Biochem & Mole Biol, Amer Soc Investigat Pathol, Amer Soc Nutr Sci, Amer Soc Pharmacol & Exptl Therapeut C1 Univ Vermont, Burlington, VT 05405 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Wake Forest Univ, Sch Med, Winston Salem, NC 27101 USA. USA, Inst Surg Res, Ft Sam Houston, TX 78123 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 4 PY 2005 VL 19 IS 4 SU S BP A669 EP A669 PN 1 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 905ZQ UT WOS:000227610704554 ER PT J AU Zwart, SR Hargens, AR Smith, SM AF Zwart, SR Hargens, AR Smith, SM TI Heritability of markers of bone metabolism SO FASEB JOURNAL LA English DT Meeting Abstract CT Experimental Biology 2005 Meeting/35th International Congress of Physiological Sciences CY MAR 31-APR 06, 2005 CL San Diego, CA SP Amer Assoc Anatomists, Amer Assoc Immunol, Amer Phtsiol Soc & Int Union Physiol Sci, Amer Soc Biochem & Mole Biol, Amer Soc Investigat Pathol, Amer Soc Nutr Sci, Amer Soc Pharmacol & Exptl Therapeut C1 NASA, Johnson Space Ctr, Human Adaptat & Countermeasures Off, Houston, TX 77058 USA. Univ Calif San Diego, Dept Orthopaed, San Diego, CA 92103 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD MAR 4 PY 2005 VL 19 IS 4 SU S BP A62 EP A63 PN 1 PG 2 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA 905ZQ UT WOS:000227610700290 ER PT J AU Semenov, VK Smirnov, A Aref'ev, VN Sinyakov, VP Sorokina, LI Ignatova, NI AF Semenov, VK Smirnov, A Aref'ev, VN Sinyakov, VP Sorokina, LI Ignatova, NI TI Aerosol optical depth over the mountainous region in central Asia (Issyk-Kul Lake, Kyrgyzstan) SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SUN PHOTOMETER; AERONET AB Aerosol optical depth measurements over Issyk-Kul Lake acquired with the handheld sun photometer Microtops II are analyzed. Aerosol found over the mountainous region at the elevation of 1650 m above sea level resembles mostly clean background conditions. The yearly aerosol optical depth at a wavelength 500 nm similar to 0.10 +/- 0.03 is in agreement with the multi-year means from the background sites of the Aerosol Robotic Network (AERONET). Over a period of 4 years optical depth showed a seasonal pattern, with a maximum observed during summer. A link has been made between new and previously acquired data in order to provide a reliable trend for the region. C1 Kyrgyzstan Natl Inst, Inst Fundamental Sci, Bishkek 720033, Kyrgyzstan. NPO Taifum, Obninsk 249020, Kaluzhskaya Obl, Russia. NASA, Goddard Space Flight Ctr, UMBC, Goddard Earth Sci & Technol Ctr, Greenbelt, MD 20771 USA. RP Semenov, VK (reprint author), Kyrgyzstan Natl Inst, Inst Fundamental Sci, Bishkek 720033, Kyrgyzstan. EM svk@elcat.kg; asmirnov@aeronet.gsfc.nasa.gov RI Smirnov, Alexander/C-2121-2009; OI Smirnov, Alexander/0000-0002-8208-1304; Lammel, Gerhard/0000-0003-2313-0628 NR 13 TC 6 Z9 6 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 MAR 4 PY 2005 VL 32 IS 5 AR L05807 DI 10.1029/2004GL021746 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 905DV UT WOS:000227548900006 ER PT J AU Fielding, EJ Talebian, M Rosen, PA Nazari, H Jackson, JA Ghorashi, M Walker, R AF Fielding, EJ Talebian, M Rosen, PA Nazari, H Jackson, JA Ghorashi, M Walker, R TI Surface ruptures and building damage of the 2003 Bam, Iran, earthquake mapped by satellite synthetic aperture radar interferometric correlation SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SOUTHEAST IRAN; GOWK FAULT; SE IRAN; DEFORMATION; DECORRELATION; INSAR; SLIP AB We use the interferometric correlation from Envisat synthetic aperture radar ( SAR) images to map the details of the surface ruptures related to the 26 December 2003 earthquake that devastated Bam, Iran. The main strike-slip fault rupture south of the city of Bam has a series of four segments with left steps shown by a narrow line of low correlation in the coseismic interferogram. This also has a clear expression in the field because of the net extension across the fault. Just south of the city limits, the surface strain becomes distributed over a width of about 500 m, probably because of a thicker layer of soft sedimentary material. Another fault north of Bam shows offset and low correlation over a wider zone in the interferograms, but it has no discrete surface rupture, possibly because of a net shortening across this fault. Taking the difference between the interferometric correlation for an interval including the earthquake and an interval before the earthquake separates the changes due to the earthquake from other effects in the partially vegetated city of Bam. We map the damage to buildings by measuring the change from high correlation to low correlation where buildings were destroyed by the earthquake. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Cambridge, Ctr Observat & Modelling Earthquakes & Tecton, Dept Earth Sci, Cambridge, England. Geol Survey Iran, Tehran, Iran. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM eric.fielding@jpl.nasa.gov; paul.rosen@jpl.nasa.gov RI Walker, Richard/D-9908-2011; NCEO, COMET+`/A-3443-2013; Fielding, Eric/A-1288-2007 OI Fielding, Eric/0000-0002-6648-8067 NR 23 TC 45 Z9 48 U1 3 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 4 PY 2005 VL 110 IS B3 AR B03302 DI 10.1029/2004JB003299 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 905EW UT WOS:000227551900001 ER PT J AU Aumann, HH Gregorich, D Gaiser, S AF Aumann, HH Gregorich, D Gaiser, S TI AIRS hyper-spectral measurements for climate research: Carbon dioxide and nitrous oxide effects SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERIC INFRARED SOUNDER AB Mid- tropospheric temperature soundings over tropical oceans by the Atmospheric Infrared Sounder, AIRS, using 4.3 micron CO2 R- branch and P- branch channels independently measure about 260 K with one Kelvin semiannual variability. The difference between the soundings, which cancels seasonal variability, has increased over the past two years by 47 +/- 9 mK/ year. This trend is explained by the increase of 2.2 +/- 0.4 ppmv/ year and 0.6 +/- 0.2 ppbv/ year in the abundance of CO2 and N2O, respectively, which results in a 35 mK/ year trend. The ability to achieve closure at this level with only two years of AIRS data is very encouraging for measurements of other trends of atmospheric temperatures relevant to climate research. AIRS covers the 3.7 to 15.4 micron region with spectral resolution of lambda/Delta lambda = 1200. AIRS was launched into a polar 705 km altitude orbit on the EOS Aqua spacecraft on May 4, 2002, and has an expected on- orbit lifetime of seven years. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Aumann, HH (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM aumann@jpl.nasa.gov NR 8 TC 27 Z9 28 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 3 PY 2005 VL 32 IS 5 AR L05806 DI 10.1029/2004GL021784 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 905DS UT WOS:000227548500004 ER PT J AU Hyman, SD Lazio, JW Kassim, NE Ray, PS Markwardt, CB Yusef-Zadeh, F AF Hyman, SD Lazio, JW Kassim, NE Ray, PS Markwardt, CB Yusef-Zadeh, F TI A powerful bursting radio source towards the Galactic Centre SO NATURE LA English DT Article ID EXTRASOLAR PLANETS; EMISSION; TRANSIENTS; SPECTRA; DWARFS; PULSAR; GALAXY AB Transient astronomical sources are typically powered by compact objects and usually signify highly explosive or dynamic events(1). Although high-time-resolution observations are often possible in radio astronomy(2), they are usually limited to quite narrow fields of view. The dynamic radio sky is therefore poorly sampled, in contrast to the situation in the X-ray and gamma-ray bands in which wide-field instruments routinely detect transient sources(3). Here we report a transient radio source, GCRT J1745 - 3009, which was detected during a moderately wide-field monitoring programme of the Galactic Centre region(4,5) at 0.33 GHz. The characteristics of its bursts are unlike those known for any other class of radio transient. If located in or near the Galactic Centre, its brightness temperature (, 10 16 K) and the implied energy density within GCRT J1745 - 3009 vastly exceed those observed in most other classes of radio astronomical sources(6), and are consistent with coherent emission processes(7) that are rarely observed. We conclude that it represents a hitherto unknown class of transient radio sources, the first of possibly many new classes that may be discovered by emerging wide-field radio telescopes(8). C1 Sweet Briar Coll, Dept Phys & Engn, Sweet Briar, VA 24595 USA. USN, EO Hulburt Ctr Space Res, Res Lab, Washington, DC 20375 USA. NASA, High Energy Astrophys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. RP Hyman, SD (reprint author), Sweet Briar Coll, Dept Phys & Engn, Sweet Briar, VA 24595 USA. EM shyman@sbc.edu OI Ray, Paul/0000-0002-5297-5278 NR 30 TC 72 Z9 73 U1 0 U2 1 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAR 3 PY 2005 VL 434 IS 7029 BP 50 EP 52 DI 10.1038/nature03400 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 902ED UT WOS:000227334600038 PM 15744294 ER PT J AU Spang, R Remedios, JJ Kramer, LJ Poole, LR Fromm, MD Muller, M Baumgarten, G Konopka, P AF Spang, R Remedios, JJ Kramer, LJ Poole, LR Fromm, MD Muller, M Baumgarten, G Konopka, P TI Polar stratospheric cloud observations by MIPAS on ENVISAT: detection method, validation and analysis of the northern hemisphere winter 2002/2003 SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID LIMB EMISSION-SPECTRA; ARCTIC STRATOSPHERE; SAM-II; AEROSOL; TEMPERATURE; VORTEX; UARS; DENITRIFICATION; SPECTROMETERS; SIGHTINGS AB The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on ENVISAT has made extensive measurements of polar stratospheric clouds (PSCs) in the northern hemisphere winter 2002/2003. A PSC detection method based on a ratio of radiances (the cloud index) has been implemented for MIPAS and is validated in this study with respect to ground-based lidar and space borne occultation measurements. A very good correspondence in PSC sighting and cloud altitude between MIPAS detections and those of other instruments is found for cloud index values of less than four. Comparisons with data from the Stratospheric Aerosol and Gas Experiment (SAGE) III are used to further show that the sensitivity of the MIPAS detection method for this threshold value of cloud index is approximately equivalent to an extinction limit of 10(-3) km(-1) at 1022 nm, a wavelength used by solar occultation experiments. The MIPAS cloud index data are subsequently used to examine, for the first time with any technique, the evolution of PSCs throughout the Arctic polar vortex up to a latitude close to 90degrees north on a near-daily basis. We find that the winter of 2002/2003 is characterised by three phases of very different PSC activity. First, an unusual, extremely cold phase in the first three weeks of December resulted in high PSC occurrence rates. This was followed by a second phase of only moderate PSC activity from 5-13 January, separated from the first phase by a minor warming event. Finally there was a third phase from February to the end of March where only sporadic and mostly weak PSC events took place. The composition of PSCs during the winter period has also been examined, exploiting in particular an infra-red spectral signature which is probably characteristic of NAT. The MIPAS observations show the presence of these particles on a number of occasions in December but very rarely in January. The PSC type differentiation from MIPAS indicates that future comparisons of PSC observations with microphysical and denitrification models might be revealing about aspects of solid particle existence and location. C1 Res Ctr Julich, ICG I, Julich, Germany. Univ Leicester, Dept Phys & Astron, SRC, EOS, Leicester LE1 7RH, Leics, England. NASA Langley Res Ctr, Hampton, VA USA. Computat Phys Inc, Springfield, VA USA. Alfred Wegener Inst, Potsdam, Germany. Leibniz Inst Atmospher Phys, Kuhlungsborn, Germany. RP Spang, R (reprint author), Res Ctr Julich, ICG I, Julich, Germany. EM r.spang@fz-juelich.de RI Fromm, Michael/F-4639-2010; Spang, Reinhold/A-2738-2013; Konopka, Paul/A-7329-2013; OI Spang, Reinhold/0000-0002-2483-5761; Baumgarten, Gerd/0000-0002-6727-284X NR 32 TC 44 Z9 44 U1 0 U2 2 PU EUROPEAN GEOSCIENCES UNION PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD MAR 2 PY 2005 VL 5 BP 679 EP 692 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 902GY UT WOS:000227344000002 ER PT J AU Randall, CE Harvey, VL Manney, GL Orsolini, Y Codrescu, M Sioris, C Brohede, S Haley, CS Gordley, LL Zawodny, JM Russell, JM AF Randall, CE Harvey, VL Manney, GL Orsolini, Y Codrescu, M Sioris, C Brohede, S Haley, CS Gordley, LL Zawodny, JM Russell, JM TI Stratospheric effects of energetic particle precipitation in 2003-2004 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ATMOSPHERE; ENHANCEMENTS; SIMULATIONS; NITROGEN; VORTEX AB Upper stratospheric enhancements in NOx (NO and NO2) were observed at high northern latitudes from March through at least July of 2004. Multi-satellite data analysis is used to examine the temporal evolution of the enhancements, to place them in historical context, and to investigate their origin. The enhancements were a factor of 4 higher than nominal at some locations, and are unprecedented in the northern hemisphere since at least 1985. They were accompanied by reductions in O-3 of more than 60% in some cases. The analysis suggests that energetic particle precipitation led to substantial NOx production in the upper atmosphere beginning with the remarkable solar storms in late October 2003 and possibly persisting through January. Downward transport of the excess NOx, facilitated by unique meteorological conditions in 2004 that led to an unusually strong upper stratospheric vortex from late January through March, caused the enhancements. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. CALTECH, NASA, Jet Prop Lab, Pasadena, CA 91125 USA. New Mexico Highlands Univ, Dept Nat Resources Management, Las Vegas, NM USA. Norwegian Inst Air Res, N-2007 Kjeller, Norway. Univ Colorado, NOAA, Space Environm Ctr, Boulder, CO 80305 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Space Environm Ctr, Boulder, CO 80309 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Chalmers, Dept Radio & Space Sci, S-41296 Gothenburg, Sweden. Univ York, Ctr Res Earth & Space Sci, Toronto, ON M3J 1PE, Canada. GATS Inc, Newport News, VA 23606 USA. NASA, Langley Res Ctr, Hampton, VA USA. Hampton Univ, Dept Phys, Ctr Atmospher Sci, Hampton, VA 23668 USA. RP Randall, CE (reprint author), Univ Colorado, Atmospher & Space Phys Lab, Campus Box 392, Boulder, CO 80309 USA. EM cora.randall@lasp.colorado.edu RI Randall, Cora/L-8760-2014; OI Randall, Cora/0000-0002-4313-4397; Sioris, Christopher/0000-0003-1168-8755 NR 14 TC 148 Z9 149 U1 2 U2 7 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 MAR 2 PY 2005 VL 32 IS 5 AR L05802 DI 10.1029/2004GL022003 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 905DO UT WOS:000227548100004 ER PT J AU Green, JL Boardsen, S Garcia, L Taylor, WWL Fung, SF Reinisch, BW AF Green, JL Boardsen, S Garcia, L Taylor, WWL Fung, SF Reinisch, BW TI On the origin of whistler mode radiation in the plasmasphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INDUCED ELECTRON-PRECIPITATION; MAGNETOSPHERICALLY REFLECTING WHISTLERS; EARTHS INNER MAGNETOSPHERE; PITCH-ANGLE DISTRIBUTIONS; WAVE ACTIVITY; CHORUS EMISSIONS; HISS GENERATION; SCATTERING LOSS; BELT ELECTRONS; ELF NOISE AB The origin of whistler mode radiation in the plasmasphere is examined from 3 years of plasma wave observations from the Dynamics Explorer and the Imager for Magnetopauseto-Aurora Global Exploration spacecraft. These data are used to construct plasma wave intensity maps of whistler mode radiation in the plasmasphere. The highest average intensities of the radiation in the wave maps show source locations and/or sites of wave amplification. Each type of wave is classified on the basis of its magnetic latitude and longitude rather than any spectral feature. Equatorial electromagnetic ( EM) emissions (similar to 30 - 330 Hz), plasmaspheric hiss (similar to 330 Hz to 3.3 kHz), chorus (similar to 2 - 6 kHz), and VLF transmitters (similar to 10 - 50 kHz) are the main types of waves that are clearly delineated in the plasma wave maps. Observations of the equatorial EM emissions show that the most intense region is on or near the magnetic equator in the afternoon sector and that during times of negative B-z ( interplanetary magnetic field) the maximum intensity moves from L values of 3 to < 2. These observations are consistent with the origin of this emission being particle-wave interactions in or near the magnetic equator. Plasmaspheric hiss shows high intensity at high latitudes and low altitudes ( L shells from 2 to 4) and in the magnetic equator with L values from 2 to 3 in the early afternoon sector. The longitudinal distribution of the hiss intensity ( excluding the enhancement at the equator) is similar to the distribution of lightning: stronger over continents than over the ocean, stronger in the summer than in the winter, and stronger on the dayside than on the nightside. These observations strongly support lightning as the dominant source for plasmaspheric hiss, which, through particle-wave interactions, maintains the slot region in the radiation belts. The enhancement of hiss at the magnetic equator is consistent with particle-wave interactions. The chorus emissions are most intense on the morningside as previously reported. At frequencies from similar to 10 to similar to 50 kHz, VLF transmitters dominate the spectrum. The maximum intensity of the VLF transmitters is in the late evening or early morning with enhancements all along L shells from 1.8 to 3. C1 NASA, Goddard Space Flight Ctr, Space Sci Data Operat Off, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Commun Analyt Div L3, Greenbelt, MD 20771 USA. QSS Grp Inc, Lanham, MD 20706 USA. Univ Massachusetts, Ctr Atmospher Res, Lowell, MA 01854 USA. RP NASA, Goddard Space Flight Ctr, Space Sci Data Operat Off, Mail Code 630,Bldg 26, Greenbelt, MD 20771 USA. EM james.green@nasa.gov RI Fung, Shing/F-5647-2012 NR 49 TC 71 Z9 71 U1 2 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD MAR 2 PY 2005 VL 110 IS A3 AR A03201 DI 10.1029/2004JA010495 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905FF UT WOS:000227552800001 ER PT J AU Wernet, MP AF Wernet, MP TI Planar particle imaging doppler velocimetry: A three-component velocity measurement technique SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT Conference on Aerodynamic Measurement Technique CY JAN, 2004 CL Reno, NV ID HIGH-SPEED FLOWS AB Digital particle imaging velocimetry (DPIV) is a high-resolution, high-accuracy, planar velocimetry technique, which provides valuable instantaneous velocity information in aeropropulsion test facilities. DPIV is capable of providing three-component flowfield measurements using a two-camera, stereo-viewing configuration. Doppler global velocimetry (DGV) is another planar velocimetry technique, which is also capable of providing three-component flow field measurements, but requires three detector systems that must be located at oblique angles from the measurement plane. The three-dimensional configurations of either technique require multiple (DGV) or at least large (stereo PIV) optical access ports in the facility in which the measurements are being conducted. In some test facilities, limited optical access is available (either a single viewing window or small optical access port), which prohibits the implementation of either technique for three-component flow measurements. A hybrid measurement technique is described, called planar particle image Doppler velocimetry (PPIDV), which combines elements from both the DPIV and DGV techniques into a single detection system capable of measuring all three components of velocity across a planar region of a flowfield through a single optical access port. The PPIDV system utilizes common components between the DPIV and DGV systems to reduce system complexity and costs. Measurements of a rotating wheel are used to verify the integrity of the technique. Then simultaneous measurements of a nozzle flow are obtained using both a stereo-viewing DPIV system and a PPIDV system. C1 NASA, John H Glenn Res Ctr, Opt Instrumentat & NDE Branch, Cleveland, OH 44135 USA. RP Wernet, MP (reprint author), NASA, John H Glenn Res Ctr, Opt Instrumentat & NDE Branch, MS-77-1,21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 14 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD MAR PY 2005 VL 43 IS 3 BP 479 EP 488 DI 10.2514/1.7917 PG 10 WC Engineering, Aerospace SC Engineering GA 905LC UT WOS:000227568600006 ER PT J AU McKenzie, RL Reinath, MS AF McKenzie, RL Reinath, MS TI Three-dimensional planar Doppler velocity measurements in a full-scale rotor wake SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT Conference on Aerodynamic Measurement Technique CY JAN, 2004 CL Reno, NV ID HIGH-SPEED FLOWS; VELOCIMETRY AB The application of planar Doppler velocimetry (PDV) measurements to three-dimensional velocity vector fields in the tip-vortex flows between the blades of a full-scale UH-60 rotor operating in the 80- by 120-Foot Wind Tunnel at NASA Ames Research Center is described. The unique capabilities of PDV for remotely measuring complex velocity fields in large-scale flows are demonstrated and the factors affecting the quality of PDV data from a large-scale facility are defined. Because the wind tunnel is a noncirculating, in-draft configuration, and very large, the principal factor that prevented the acquisition of time-resolved, instantaneous measurements was the spatially and temporally sporadic behavior of the aerosol seeding in the sample area. Nevertheless, time-averaged velocity fields were obtained that characterize the locations and velocity distributions of the blade tip vortices and that provide magnitudes and directions of the velocity vectors in the surrounding flow with better than 1-cm spatial resolution within a square, 1.2 m x 1.2 m, sample area from distances up to 20 m. C1 MetroLaser Inc, Sunnyvale, CA 94087 USA. NASA, Ames Res Ctr, Adv Aircraft & Powered Lift Branch, Moffett Field, CA 94035 USA. RP McKenzie, RL (reprint author), MetroLaser Inc, 825 Cathedral Dr, Sunnyvale, CA 94087 USA. EM rmckenzie@metrolaserinc.com NR 25 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 0001-1452 J9 AIAA J JI AIAA J. PD MAR PY 2005 VL 43 IS 3 BP 489 EP 499 DI 10.2514/1.12205 PG 11 WC Engineering, Aerospace SC Engineering GA 905LC UT WOS:000227568600007 ER PT J AU Tucker, PG Rumsey, CL Spalart, PR Bartels, RE Biedron, RT AF Tucker, PG Rumsey, CL Spalart, PR Bartels, RE Biedron, RT TI Computations of wall distances based on differential equations SO AIAA JOURNAL LA English DT Article; Proceedings Paper CT Conference on Aerodynamic Measurement Technique CY JAN, 2004 CL Reno, NV ID FLOWS AB The use of differential equations such as Eikonal, Hamilton-Jacobi, and Poisson for the economical calculation of the nearest (normal) wall distance d, which is needed by some turbulence models, is explored. Modifications that could palliate some turbulence-modeling anomalies are also discussed. Economy is of especial value for deforming/adaptive grid problems. For these, ideally, d is repeatedly computed. It is shown that the Eikonal and Hamilton-Jacobi equations can be easy to implement when written in implicit (or iterated) advection and advection-diffusion equation analogous forms, respectively. These, like the Poisson Laplacian term, are commonly occurring in computational-fluid-dynamics (CFD) solvers, allowing the reuse of efficient algorithms and code components. The use of the NASA CFL3D CFD program to solve the implicit Eikonal and Hamilton-Jacobi equations is explored. The reformulated d equations are easy to implement and are found to have robust convergence. For accurate Eikonal solutions, upwind metric differences are required. The Poisson approach is also found effective and easiest to implement. Hence this method is recommended. Modified distances are not found to affect global outputs such as lift and drag significantly, at least in common situations such as airfoil flows. C1 Univ Coll Swansea, Sch Engn, Civil & Computat Engn Ctr, Swansea SA2 8PP, W Glam, Wales. NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA. Boeing Commercial Airplane Co, Seattle, WA 98124 USA. NASA, Langley Res Ctr, Aeroelastic Branch, Hampton, VA 23681 USA. RP Tucker, PG (reprint author), Univ Coll Swansea, Sch Engn, Civil & Computat Engn Ctr, Singleton Pk, Swansea SA2 8PP, W Glam, Wales. NR 17 TC 23 Z9 23 U1 2 U2 6 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 MAR PY 2005 VL 43 IS 3 BP 539 EP 549 DI 10.2514/1.8626 PG 11 WC Engineering, Aerospace SC Engineering GA 905LC UT WOS:000227568600012 ER PT J AU Norikane, JH Prenger, JJ Rouzan-Wheeldon, DT Levine, HG AF Norikane, JH Prenger, JJ Rouzan-Wheeldon, DT Levine, HG TI A comparison of soil moisture sensors for space flight applications SO APPLIED ENGINEERING IN AGRICULTURE LA English DT Article DE capacitance; heat-pulse; soil moisture sensors; tensiometer; turface ID POROUS TUBE; WATER; MICROGRAVITY; MEDIA; WHEAT; MIR AB Plants will be an important part of future long-term space missions. Automated plant growth systems require accurate and reliable methods of monitoring soil moisture levels. There are a number of different methods to accomplish this task. This study evaluated sensors using the capacitance method (ECH20), the heat-pulse method (TMAS), and tensiometers, compared to soil water loss measured gravimetrically in a side-by-side test. The experiment monitored evaporative losses from substrate compartments filled with 1- to 2-mm baked calcinated clay media. The ECH20 data correlated well with the gravimetric measurements, but over a limited range of soil moisture. The averaged TMAS sensor data overstated soil moisture content levels. The tensiometer data appeared to track evaporative losses in the 0.5- to 2.5-kPa range of matric potential that corresponds to the water content needed to grow plants. This small range is characteristic of large particle media, and thus high-resolution tensiometers are required to distinguish changing moisture contents in this range. C1 Univ Kentucky, Dept Agr & Biosyst Engn, Lexington, KY 40546 USA. NASA, Biol Sci Off, Kennedy Space Ctr, FL USA. RP Norikane, JH (reprint author), Univ Kentucky, Dept Agr & Biosyst Engn, 128 CE Barnhart Bldg, Lexington, KY 40546 USA. EM jnorikane@bae.uky.edu NR 32 TC 3 Z9 3 U1 4 U2 7 PU AMER SOC AGRICULTURAL ENGINEERS PI ST JOSEPH PA 2950 NILES RD, ST JOSEPH, MI 49085-9659 USA SN 0883-8542 J9 APPL ENG AGRIC JI Appl. Eng. Agric. PD MAR PY 2005 VL 21 IS 2 BP 211 EP 216 PG 6 WC Agricultural Engineering SC Agriculture GA 912MJ UT WOS:000228082300010 PM 15934177 ER PT J AU Webster, CR AF Webster, CR TI Measuring methane and its isotopes (CH4)-C-12, (CH4)-C-13, and CH3D on the surface of Mars with in situ laser spectroscopy SO APPLIED OPTICS LA English DT Article ID ATMOSPHERIC METHANE; MU-M; ABSORPTION SPECTROMETER; ROOM-TEMPERATURE; FAST-RESPONSE; CARBON; CH4; FRACTIONATION; RATIOS; N2O AB In light of the recent discovery of methane on Mars and its possible biological origin, a strategy is described for making in situ measurements of methane and its isotopes on the surface of Mars by laser spectroscopy in the 3.3-mum wavelength region. An instrument of reasonable mass (similar to1 lb) and power (few watts) is capable of measuring mixing ratios down to 0.1 part per 109 by volume, a hundred times lower than recently reported observations. Making accurate measurements of (CH4)-C-13 and CH3D will be more difficult. For measuring delta(13)C to 10parts per thousand and deltaD to 50parts per thousand, sample preconcentration will be required to similar to3 parts per 10(6) by volume for delta(13)C and to similar to40 parts per 10(6) by volume for deltaD. This need would be mitigated by the discovery of larger local abundances of methane near the source regions. (C) 2005 Optical Society of America. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Webster, CR (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM chris.r.webster@jpl.nasa.gov NR 49 TC 43 Z9 44 U1 1 U2 7 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 MAR 1 PY 2005 VL 44 IS 7 BP 1226 EP 1235 DI 10.1364/AO.44.001226 PG 10 WC Optics SC Optics GA 903XT UT WOS:000227459600015 PM 15765703 ER PT J AU Dholakia, GR Fan, W Meyyappan, M AF Dholakia, GR Fan, W Meyyappan, M TI Effect of monolayer order and dynamics on the electronic transport of molecular wires SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; SCANNING-TUNNELING-MICROSCOPY; NEGATIVE DIFFERENTIAL RESISTANCE; ATOMIC-FORCE MICROSCOPY; ELECTRICAL-CONDUCTION; SINGLE MOLECULES; AU(111); SURFACES; GOLD; ALKANETHIOLS AB This article discusses the self assembly of conjugated thiol molecular wires on Au(111) substrates and their charge transport studied by scanning tunneling microscopy and spectroscopy. Molecular resolution imaging of the conjugated thiols show that differences in their structure and inter molecular interactions result in an ordering on gold that is different from the hexagonal symmetry found in alkanethiols. Tunneling spectroscopy on the molecular wires provides information about their intrinsic electronic properties such as the origin of the observed conductance gap and asymmetry in the I-Vs. Further by concurrent topographic and tunneling spectroscopic studies on a conjugated thiol molecule self assembled with and without molecular order, we show that packing and order determine the response of the monolayer to various competing interactions and that the presence of molecular order is very important for reproducible transport measurements. Competing forces between the electric field, intermolecular interactions, tip-molecule physisorption and substrate-molecule chemisorption impact the transport measurements and its reliability. This study points to the fact that molecular electronic devices should be designed to be tolerant to such fluctuations and dynamics. C1 NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. ELORET, Sunnyvale, CA 94087 USA. RP NASA, Ames Res Ctr, Ctr Nanotechnol, Moffett Field, CA 94035 USA. EM gdholakia@mail.arc.nasa.gov NR 46 TC 7 Z9 7 U1 0 U2 8 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0947-8396 EI 1432-0630 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD MAR PY 2005 VL 80 IS 6 BP 1215 EP 1223 DI 10.1007/s00339-004-3165-1 PG 9 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 907DS UT WOS:000227696100011 ER PT J AU Bratkovsky, AM Osipov, VV AF Bratkovsky, AM Osipov, VV TI Efficient spin injection and extraction in modified reverse and forward biased ferromagnetic-semiconductor junctions and low-power ultrafast spin injection devices SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID LIGHT-EMITTING DIODE; GIANT MAGNETORESISTANCE; ROOM-TEMPERATURE; TRANSPORT; POLARIZATION; SPINTRONICS; BARRIER; CO; HETEROSTRUCTURE; TRANSISTOR AB This paper addresses recent theoretical and experimental advances in obtaining large spin polarization in semiconductors. In particular, we describe tunneling of electrons between nonmagnetic semiconductors (S) and ferromagnets (FM) through a Schottky barrier modified by very thin heavily doped interfacial layer. It is shown that in such reverse (forward) biased FM-S junctions electrons with a certain spin projection can be efficiently injected in (extracted from) S. This occurs due to spin filtering of electrons in a tunneling process. We find conditions for most efficient extraction and accumulation of spin and show that spin polarization of electrons near the interface can, at least in principle, be made close to 100% in nondegenerate S at room temperature and certain bias voltages. Extraction of spin can proceed in degenerate semiconductors at any (low) temperature. A new class of spin valve ultrafast devices with small dissipated power is described: a magnetic sensor, a spin transistor, an amplifier, a frequency multiplier, and a square-law detector. C1 Hewlett Packard Labs, Palo Alto, CA 94304 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hewlett Packard Labs, 1501 Page Mill Rd, Palo Alto, CA 94304 USA. EM alexb@hpl.hp.com NR 62 TC 4 Z9 4 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0947-8396 EI 1432-0630 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD MAR PY 2005 VL 80 IS 6 BP 1237 EP 1246 DI 10.1007/s00339-004-3178-9 PG 10 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 907DS UT WOS:000227696100014 ER PT J AU Ueta, T Murakawa, K Meixner, M AF Ueta, T Murakawa, K Meixner, M TI Hubble Space Telescope nicmos imaging polarimetry of proto-planetary nebulae: Probing the dust shell structure via polarized light SO ASTRONOMICAL JOURNAL LA English DT Article DE circumstellar matter; planetary nebulae : general; reflection nebulae; stars : AGB and post-AGB; stars : mass loss ID ASYMPTOTIC GIANT BRANCH; PLANETARY-NEBULAE; CIRCUMSTELLAR ENVELOPES; ABUNDANCE ANALYSIS; STELLAR EVOLUTION; IRAS Z02229+6208; CARBON STAR; AGB STARS; MASS-LOSS; CANDIDATES AB Using NICMOS on the Hubble Space Telescope, we have performed imaging polarimetry of proto-planetary nebulae (PPNs). Our objective is to study the structure of optically thin circumstellar shells of post-asymptotic giant branch (AGB) stars by separating dust-scattered, linearly polarized starlight from unpolarized direct starlight. This unique technique allows us to probe faint reflection nebulae around the bright central star, which can be buried under the point-spread function of the central star in conventional imaging. Our observations and archival search have yielded polarimetric images for five sources: IRAS 07134+1005 (HD 56126), 06530-0213, 04296+3429, (Z)02229+6208, and 16594-4656. These images have revealed the circumstellar dust distribution in unprecedented detail via polarized intensity maps, providing a basis for understanding the three-dimensional structure of these dust shells. We have observationally confirmed the presence of the inner cavity caused by the cessation of AGB mass loss, and the internal shell structures, which are strongly tied to the progenitor star's mass-loss history on the AGB. We have also found that equatorial enhancement in these circumstellar shells comes with various degrees of contrast, suggesting a range of optical depths in these optically thin shells. Our data support the interpretation that the dichotomy of PPN morphologies is due primarily to differences in optical depth and secondarily to the inclination effect. The polarization maps reveal a range of inclination angles for these optically thin reflection nebulae, dispelling the notion that elliptical nebulae are pole-on bipolar nebulae. C1 Observ Royal Belgique, B-1180 Brussels, Belgium. Natl Astron Observ Japan, Subaru Telescope, Hilo, HI 96720 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Ueta, T (reprint author), NASA, Ames Res Ctr, SOFIA, Mail Stop 211-3, Moffett Field, CA 94035 USA. EM tueta@mail.sofia.usra.edu; murakawa@subaru.naoj.org; meixner@stsci.edu NR 48 TC 24 Z9 24 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-6256 J9 ASTRON J JI Astron. J. PD MAR PY 2005 VL 129 IS 3 BP 1625 EP 1641 DI 10.1086/427541 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 904UL UT WOS:000227523100028 ER PT J AU Fitzpatrick, EL Massa, D AF Fitzpatrick, EL Massa, D TI Determining the physical properties of the B stars. II. Calibration of synthetic photometry SO ASTRONOMICAL JOURNAL LA English DT Article DE stars : abundances; stars : atmospheres; stars : early-type; stars : fundamental parameters ID LARGE-MAGELLANIC-CLOUD; REFINED MK CLASSIFICATION; FUNDAMENTAL PROPERTIES; EFFECTIVE TEMPERATURE; ECLIPSING BINARIES; BOLOMETRIC CORRECTIONS; MODEL ATMOSPHERES; INTERSTELLAR EXTINCTION; SPECTRAL DISTRIBUTION; STROMGREN PHOTOMETRY AB We present a new calibration of optical (UBV, Stromgren u nu by beta, and Geneva) and near-IR (Johnson RIJHK and Two Micron All Sky Survey) photometry for B and early A stars derived from Kurucz ATLAS9 model atmospheres. sphres. Our sample of stars consists of 45 normal nearby B and early A stars that have high-quality, low-resolution IUE spectra and accurate Hipparcos parallaxes. The calibration is unique because it relies only on the UV spectral energy distributions, the absolute flux calibration of the V filter, and the Hipparcos distances to determine the appropriate model atmospheres for the program stars. These models are then used to calibrate the synthetic photometry. We compare our results with previous well-accepted results and provide a thorough discussion of the random errors and systematic effects affecting the calibration. In particular, we demonstrate the influence of nu sin i on surface gravities derived from fitting model atmospheres. Finally, we discuss some of our intended applications of this new calibration. C1 Villanova Univ, Dept Astron & Astrophys, Villanova, PA 19085 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Fitzpatrick, EL (reprint author), Villanova Univ, Dept Astron & Astrophys, Villanova, PA 19085 USA. EM fitz@astronomy.villanova.edu; massa@derckmassa.net NR 70 TC 35 Z9 37 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 MAR PY 2005 VL 129 IS 3 BP 1642 EP 1662 DI 10.1086/427855 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 904UL UT WOS:000227523100029 ER PT J AU Weis, K Stahl, O Bomans, DJ Davidson, K Gull, TR Humphreys, RM AF Weis, K Stahl, O Bomans, DJ Davidson, K Gull, TR Humphreys, RM TI VLT uves observations of the balmer line variations of eta carinae during the 2003 spectroscopic event SO ASTRONOMICAL JOURNAL LA English DT Article DE stars : individual (eta carinae); stars : peculiar; stars : variables : other ID LONG-PERIOD BINARY; HOMUNCULUS-NEBULA; STAR; POLARIZATION; HYPOTHESIS; CYCLE; SHAPE AB We present high spectral resolution echelle observations of the Balmer line variations during the 2003.5 "spectroscopic event'' of eta Carinae. Spectra have been recorded of both eta Car and the Homunculus at the "FOS4'' position in its southeast lobe. This spot shows a reflected stellar spectrum that is less contaminated by nebular emission lines than ground-based observations of the central object itself. Our observations show that the spectroscopic event is much less pronounced at this position than when seen directly on eta Car using the Hubble Space Telescope Space Telescope Imaging Spectrograph. Assuming that the reflected spectrum is indeed latitude-dependent, this indicates that the spectral changes during the event seen pole-on (FOS4) are different from those closer to the equator (directly on the star). In contrast to the spectrum of the star, the scattered spectrum of FOS4 always shows pronounced P Cygni absorption with little variation across the spectroscopic event. After that event an additional high-velocity absorption component appears. The emission profile is more peaked at FOS4 and consists of at least three distinct components, of which the reddest one shows the strongest changes through the event. The data seem to be compatible with changes in latitudinal wind structure of a single star, with or without the help of a secondary star, or the onset of a shell ejection during the spectroscopic event. C1 Ruhr Univ Bochum, Inst Astron, D-44780 Bochum, Germany. Landessternwarte Heidelberg Konigstuhl, D-69117 Heidelberg, Germany. Univ Minnesota, Dept Astron, Minneapolis, MN 55455 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Weis, K (reprint author), Ruhr Univ Bochum, Inst Astron, Univ Str 150, D-44780 Bochum, Germany. EM kweis@astro.rub.de; O.Stahl@lsw.uni-heidelberg.de; bomans@astro.rub.de; kd@astro.umn.de; Theodore.R.Gull@nasa.gov; roberta@aps.umn.edu RI Gull, Theodore/D-2753-2012 OI Gull, Theodore/0000-0002-6851-5380 NR 30 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 0004-6256 J9 ASTRON J JI Astron. J. PD MAR PY 2005 VL 129 IS 3 BP 1694 EP 1699 DI 10.1086/428005 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 904UL UT WOS:000227523100033 ER PT J AU Rodriguez, J Cabanac, C Hannikainen, DC Beckmann, V Shaw, SE Schultz, J AF Rodriguez, J Cabanac, C Hannikainen, DC Beckmann, V Shaw, SE Schultz, J TI Unveiling the nature of the high energy source IGR J19140+0951 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE X-rays : binaries; X-rays : individual : IGR J19140+0951; accretion, accretion disks; gamma-rays : observations ID RAY TIMING EXPLORER; NEUTRON-STARS; VELA X-1; SPECTRA; PERFORMANCE; CHANDRA; NOVAE; RXTE AB We report on high energy observations of IGR J19140+0951 performed with RXTE on three occasions in 2002, 2003 and 2004, and INTEGRAL during a very well sampled and unprecedented high energy coverage of this source from early-March to mid-May 2003. Our analysis shows that IGR J19140+0951 spends most of its time in a very low luminosity state, probably corresponding to the state observed with RXTE, and characterised by thermal Comptonisation. In some occasions we observe variations of the luminosity by a factor of about 10 during which the spectrum can show evidence for a thermal component, besides thermal Comptonisation by a hotter plasma than during the low luminosity state. The spectral parameters obtained from the spectral fits to the INTEGRAL and RXTE data strongly suggest that IGR J19140+0951 hosts a neutron star rather than a black hole. Very importantly, we observe variations of the absorption column density ( with a value as high as similar to 10(23) cm(-2)). Our spectral analysis also reveals a bright iron line detected with both RXTE/PCA and INTEGRAL/JEM-X, at different levels of luminosity. We discuss these results and the behaviour of IGR J19140+0951, and show, by comparison with other well known systems (Vela X-1, GX 301-2, 4U 2206+54), that IGR J19140+0951 is most probably a High Mass X-ray Binary. C1 Ctr Etud Saclay, DAPNIA, Serv Astrophys, CNRS,FRE 2591, F-91191 Gif Sur Yvette, France. INTEGRAL Sci Data Ctr, CH-1290 Versoix, Switzerland. Observ Grenoble, Astrophys Lab, F-38041 Grenoble, France. Univ Helsinki Observ, Helsinki 00014, Finland. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Dept Phys, Joint Ctr Astrophys, Baltimore, MD 21250 USA. Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. RP Rodriguez, J (reprint author), Ctr Etud Saclay, DAPNIA, Serv Astrophys, CNRS,FRE 2591, Bat 709, F-91191 Gif Sur Yvette, France. EM jrodriguez@cea.fr OI Rodriguez, Jerome/0000-0002-4151-4468 NR 43 TC 26 Z9 26 U1 0 U2 2 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 MAR PY 2005 VL 432 IS 1 BP 235 EP 247 DI 10.1051/0004-6361:20041854 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 904JR UT WOS:000227493100026 ER PT J AU Bewsher, D Innes, DE Parnell, CE Brown, DS AF Bewsher, D Innes, DE Parnell, CE Brown, DS TI Comparison of blinkers and explosive events: A case study SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE Sun : transition region ID SOLAR TRANSITION REGION; 2D STRATIFIED ATMOSPHERES; QUIET-SUN; MAGNETIC RECONNECTION; DOPPLER SHIFTS; ACTIVE-REGION; SUMER; CDS; CONSEQUENCES; DYNAMICS AB Blinkers are brightenings at network cell junctions that are traditionally identified with SOHO/CDS and explosive events or high velocity events are identified in high resolution UV spectra obtained from HRTS and SOHO/ SUMER. Criteria are determined to facilitate objective automatic identification of both blinkers and explosive events in both SOHO/ CDS and SOHO/ SUMER data. Blinkers are identified in SUMER data, if the temporal resolution of the data is reduced to that of CDS. Otherwise short lived, localised intensity enhancements that make up the blinker are identified. Explosive events are identified in CDS data when the line width is significantly increased, and occasionally if there is an enhancement in the wing of the line profile. A theoretical statistical model is presented which hypothesises that blinkers and explosive events are random and not connected in any way. The results given in this paper suggest that this hypothesis can not be rejected and our probability interpretation of the recent results of Brkovic & Peter ( 2004, A&A, 422, 709) are inconclusive. C1 NASA, ESA Res & Sci Support Dept, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Max Planck Inst Aeron, D-37191 Katlenburg Lindau, Germany. Univ St Andrews, Math Inst, St Andrews KY16 9SS, Fife, Scotland. RP Bewsher, D (reprint author), NASA, ESA Res & Sci Support Dept, Goddard Space Flight Ctr, Mailcode 682-3, Greenbelt, MD 20771 USA. EM dbewsher@esa.nascom.nasa.gov OI Brown, Daniel/0000-0002-1618-8816; Bewsher, Danielle/0000-0002-6351-5170 NR 41 TC 10 Z9 11 U1 0 U2 2 PU E D P SCIENCES PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD MAR PY 2005 VL 432 IS 1 BP 307 EP U74 DI 10.1051/0004-6361:20041171 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 904JR UT WOS:000227493100032 ER PT J AU Ruiterkamp, R Cox, NLJ Spaans, M Kaper, L Foing, BH Salama, F Ehrenfreund, P AF Ruiterkamp, R Cox, NLJ Spaans, M Kaper, L Foing, BH Salama, F Ehrenfreund, P TI PAH charge state distribution and DIB carriers: Implications from the line of sight toward HD 147889 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE ISM : clouds; ISM : abundances; ISM : individual objects : HD 147889; ISM : molecules ID POLYCYCLIC AROMATIC-HYDROCARBONS; DIFFUSE INTERSTELLAR BANDS; ULTRAVIOLET-ABSORPTION SPECTRA; FUNCTIONAL THEORY CALCULATIONS; PHOTON-DOMINATED REGIONS; PHOTOELECTRON-SPECTRA; POLYNUCLEAR AROMATICS; MASS-SPECTROMETRY; EXTINCTION CURVE; RADIATION-FIELD AB We have computed physical parameters such as density, degree of ionization and temperature, constrained by a large observational data set on atomic and molecular species, for the line of sight toward the single cloud HD147889. Diffuse interstellar bands ( DIBs) produced along this line of sight are well documented and can be used to test the PAH hypothesis. To this effect, the charge state fractions of different polycyclic aromatic hydrocarbons (PAHs) are calculated in HD147889 as a function of depth for the derived density, electron abundance and temperature profile. As input for the construction of these charge state distributions, the microscopic properties of the PAHs, e. g., ionization potential and electron affinity, are determined for a series of symmetry groups. The combination of a physical model for the chemical and thermal balance of the gas toward HD147889 with a detailed treatment of the PAH charge state distribution, and laboratory and theoretical data on specific PAHs, allow us to compute electronic spectra of gas phase PAH molecules and to draw conclusions about the required properties of PAHs as DIB carriers. We find the following. 1) The variation of the total charge state distribution of each specific class ( series) of PAH in the translucent cloud toward HD147889 ( and also of course for any other diffuse/ translucent cloud) depends strongly on the molecular symmetry and size ( number of p electrons). This is due to the strong effects of these parameters on the ionization potential of a PAH. 2) Different wavelength regions in the DIB spectrum are populated preferentially by different PAH charge states depending on the underlying PAH size distribution. 3) The PAH size distribution for HD147889 is constrained by the observed DIB spectrum to be Gaussian with a mean of 50 carbon atoms. 4) For the given PAH size distribution it is possible to constrain the total small catacondensed PAH column density along the line of sight to HD147889 to 2.4 x 10(14) cm(-2) by comparing the total observed UV extinction to the strong UV absorptions of neutral PAHs in the 2000-3000 Angstrom region. 5) Catacondensed PAHs with sizes above some 40 C-atoms are expected to show strong DIBS longward of 10 000 Angstrom. Large condensed PAHs in the series, pyrene, coronene, ovalene,...., on the other hand, mainly absorb between 4000 and 10 000 Angstrom but extrapolation to even larger pericondensed PAHs in this series also shows strong absorptions longward of 10 000 Angstrom. 6) Only the weak DIBs in HD147889 could be reproduced by a mix of small catacondensed PAHs (< 50 C atoms) while for large pericondensed PAHs ( 50 < C atoms < 100) the intermediate DIBs are well reproduced. Small catacondensed PAHs cannot contribute more than 50% of the total observed equivalent width toward HD147889. Strong DIBs can only be reproduced by addition of very specific PAH molecules or homologue series to the sample set (i.e., a small number of PAHs with high oscillator strength or a large number of PAHs with a low oscillator strength). An outline is provided for a more general application of this method to other lines of sight, which can be used as a pipeline to compute the spectroscopic response of a PAH or group of PAHs in a physical environment constrained by independent (non-DIB) observations. C1 Leiden Observ, NL-2300 RA Leiden, Netherlands. Astron Inst Anton Pannekoek, NL-1098 SJ Amsterdam, Netherlands. Kapteyn Astron Inst, NL-9700 AV Groningen, Netherlands. European Space Agcy, Res & Sci Support Dept, NL-2200 AG Noordwijk, Netherlands. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Ruiterkamp, R (reprint author), Leiden Observ, POB 9513, NL-2300 RA Leiden, Netherlands. EM ruiterka@strw.leidenuniv.nl RI Salama, Farid/A-8787-2009 OI Salama, Farid/0000-0002-6064-4401 NR 68 TC 41 Z9 41 U1 1 U2 9 PU E D P SCIENCES PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD MAR PY 2005 VL 432 IS 2 BP 515 EP + DI 10.1051/0004-6361:20040331 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 904JS UT WOS:000227494200023 ER PT J AU Shaw, SE Mowlavi, N Rodriguez, J Ubertini, P Capitanio, F Ebisawa, K Eckert, D Courvoisier, TJL Produit, N Walter, R Falanga, M AF Shaw, SE Mowlavi, N Rodriguez, J Ubertini, P Capitanio, F Ebisawa, K Eckert, D Courvoisier, TJL Produit, N Walter, R Falanga, M TI Discovery of the INTEGRAL X/gamma-ray transient IGR J00291+5934: A comptonised accreting ms pulsar? SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE gamma-rays : observations; pulsars : individual IGR J00291+5934 ID MILLISECOND PULSAR; SAX J1808.4-3658; EMISSION AB We report the discovery of a high-energy transient with the IBIS/ISGRI detector on board the INTEGRAL observatory. The source, namely IGR J00291+5934, was first detected on 2nd December 2004 in the routine monitoring of the IBIS/ISGRI 20- 60 keV images. The observations were conducted during Galactic Plane Scans, which are a key part of the INTEGRAL Core Programme observations. After verifying the basic source behaviour, the discovery was announced on 3rd December. The transient shows a hard Comptonised spectrum, with peak energy release at about 20 keV and a total luminosity of similar to 0.9 x 10(36) erg s(-1) in the 5-100 keV range, assuming a distance of 3 kpc. Following the INTEGRAL announcement of the discovery of IGR J00291+5934, a number of observations were made by other instruments. We summarise the results of those observations and, together with the INTEGRAL data, identifiy IGR J00291+5934 as the 6th member of a class of accreting X-ray millisecond pulsars. C1 Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. INTEGRAL Sci Data Ctr, CH-1290 Versoix, Switzerland. CEA Saclay, DSM, DAPNIA, SAp,CNRS,FRE 2591, F-91191 Gif Sur Yvette, France. Observ Geneva, CH-1290 Sauverny, Switzerland. INAF, CNR, Ist Astrofis Spaziale, I-00133 Rome, Italy. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. EM simon.shaw@obs.unige.ch NR 34 TC 18 Z9 18 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 MAR PY 2005 VL 432 IS 1 BP L13 EP L16 DI 10.1051/0004-6361:200500011 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 904JR UT WOS:000227493100004 ER PT J AU Castro-Carrizo, A Bujarrabal, V Contreras, CS Sahai, R Alcolea, J AF Castro-Carrizo, A Bujarrabal, V Contreras, CS Sahai, R Alcolea, J TI The disrupted molecular envelope of Frosty Leo SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : individual : Frosty Leo; stars : circumstellar matter; stars : AGB and post-AGB; radio lines : stars; stars : mass-loss ID IRAS 09371+1212; PROTOPLANETARY NEBULAE; CIRCUMSTELLAR ENVELOPE; STELLAR EVOLUTION; MASS-LOSS; STARS; IRAS-09371+1212; MOMENTUM; DYNAMICS; OUTFLOWS AB We present maps of CO emission in the protoplanetary nebula Frosty Leo. Observations of the rotational transitions (CO)-C-12 J = 2- 1 and 1 - 0 have been obtained with the IRAM interferometer and the OVRO array. The molecular envelope of Frosty Leo is found to be complex and compact; most of the gas extends less than or similar to6" and shows a structure that is very different to the extended optical nebula. It is composed of a central ring-like structure, whose symmetry axis is inclined similar to-40degrees with respect to the sky plane and expands at speeds of up to similar to 30 km s(-1), and high-velocity jets distributed along the symmetry axis of the ring, which reach expansion velocities as high as similar to 75 km s(-1). The symmetry axis of the molecular jets in the plane of the sky coincides with the direction of some jet-like features seen in the optical, which are not aligned at all with the main symmetry axis of the optical nebula. The brightness distribution of the ring presents a clumpy structure. We have modeled the spatio-kinematical distribution of, and the excitation conditions in, the molecular envelope. For both transitions, the (CO)-C-12 emission is found to be very optically thick in the center of the nebula. From our best-fit model, we find that the nebular particle density varies between similar to 10(5) cm(-3) and similar to 10(3) cm(-3), and that the rotational temperature is very low, similar to 10 K. The kinematical lifetime of the molecular jets is similar to 1700 yr, long in comparison with the lifetime of the post-AGB winds of most PPNe. It is very remarkable that the bulk of the gas accelerated during the post-AGB phase of Frosty Leo is located within the central ring, reaching expansion velocities of up to similar to 30 km s(-1). The central ring-like distribution of Frosty Leo is probably not the undisrupted remnant of the previous AGB envelope ( as found for most PPNe), but its dynamics likely result from multiple post-AGB interactions. C1 Inst Radio Astron Millimetr, F-38406 St Martin Dheres, France. IGN, Observ Astron Nacl, Alcala De Henares 28803, Spain. CALTECH, Dept Astron, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. IGN, Observ Astron Nacl, Madrid 28014, Spain. RP Castro-Carrizo, A (reprint author), Inst Radio Astron Millimetr, 300 Rue Piscine, F-38406 St Martin Dheres, France. EM ccarrizo@iram.fr; v.bujarrabal@oan.es; sanchez@astro.caltech.edu; Raghvendra.Sahai@jpl.nasa.gov; j.alcolea@oan.es NR 28 TC 14 Z9 14 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD MAR PY 2005 VL 431 IS 3 BP 979 EP U16 DI 10.1051/0004-6361:20041482 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 904JQ UT WOS:000227492900018 ER PT J AU van der Tak, FFS Tuthill, PG Danchi, WC AF van der Tak, FFS Tuthill, PG Danchi, WC TI Subarcsecond mid-infrared and radio observations of the W3IRS5 protocluster SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : circumstellar matter; stars : formation; instrumentation : high angular resolution; ISM : individual objects : W3IRS5 ID YOUNG STELLAR OBJECTS; ULTRACOMPACT HII-REGIONS; WATER MASER OBSERVATIONS; HIGH-RESOLUTION; MASSIVE STARS; SPECKLE INTERFEROMETRY; INFRARED OBSERVATIONS; RECOMBINATION LINE; MOLECULAR CLOUDS; CONTINUUM AB Observations at mid-infrared ( 4.8 - 17.65 mum) and radio ( 0.7 - 1.3 cm) wavelengths are used to constrain the structure of the high-mass star-forming region W3 IRS5 on 0."1 ( 200 AU) scales. Two bright mid-infrared sources are detected, as well as diffuse emission. The bright sources have associated compact radio emission and probably are young high-mass stars. The measured sizes and estimated temperatures indicate that these sources together can supply the observed far-infrared luminosity. However, an optically thick radio source with a possible mid-infrared counterpart may also contribute significant luminosity; if so, it must be extremely deeply embedded. The infrared colour temperatures of 350 - 390 K and low radio brightness suggest gravitational confinement of the H II regions and ongoing accretion at a rate of a few 10(-8) M-. yr(-1) or more. Variations in the accretion rate would explain the observed radio variability. The low estimated foreground extinction suggests the existence of a cavity around the central stars, perhaps blown by stellar winds. At least three radio sources without mid-infrared counterparts appear to show proper motions of similar to 100 km s(-1), and may be deeply embedded young runaway OB stars, but more likely are clumps in the ambient material which are shock-ionized by the OB star winds. C1 Max Planck Inst Radioastron, D-53121 Bonn, Germany. Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP van der Tak, FFS (reprint author), Max Planck Inst Radioastron, Hugel 69, D-53121 Bonn, Germany. EM vdtak@mpifr-bonn.mpg.de NR 60 TC 30 Z9 30 U1 0 U2 0 PU E D P SCIENCES PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD MAR PY 2005 VL 431 IS 3 BP 993 EP 1005 DI 10.1051/0004-6361:20041595 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 904JQ UT WOS:000227492900019 ER PT J AU Stecker, FW Scully, ST AF Stecker, FW Scully, ST TI Lorentz invariance violation and the spectrum and source power of ultrahigh energy cosmic rays SO ASTROPARTICLE PHYSICS LA English DT Article DE cosmic rays; lorentz invariance; quantum gravity; gamma-ray bursts ID QUANTUM-GRAVITY; RADIATION; UNIVERSE; BURSTS; TESTS AB Owing to their isotropy, it is generally believed that ultrahigh energy cosmic rays (UHECRs) are extragalactic in origin. It is then expected that interactions of these cosmic rays with photons of the cosmic background radiation (CBR) should produce a drastic reduction in their flux above and energy of about 5 x 10(19) eV (50 EeV), the so-called "GZK effect". At present, the existence of this effect is uncertain owing to conflicting observational data and small number statistics. We show here that a small amount of Lorentz invariance violation (LIV), which could turn off photo-meson interactions of UHECRs with the CBR, could explain the UHECR spectrum as measured by AGASA which shows an excess of UHECRs at energies above 100 EeV. If new results from the Auger array agree with the AGASA spectrum, this may be interpreted as evidence for a small amount of LIV. If, on the other hand, the new results are consistent with the HiRes results favoring a GZK effect, this would place severe constraints on LIV and, by implication, on some Planck scale quantum gravity models. We also discuss the power requirements needed to explain the UHECR spectrum for a range of assumptions, including source evolution and LIV and show that in all cases our results disfavor a gamma-ray burst origin for the UHECRs. (c) 2005 Elsevier B.V. All rights reserved. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. James Madison Univ, Harrisonburg, VA 22807 USA. RP NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. EM floyd.w.stecker@iiasa.gov RI Stecker, Floyd/D-3169-2012 NR 35 TC 40 Z9 40 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-6505 EI 1873-2852 J9 ASTROPART PHYS JI Astropart Phys. PD MAR PY 2005 VL 23 IS 2 BP 203 EP 209 DI 10.1016/j.astropartphys.2005.01.001 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 909IE UT WOS:000227852800004 ER PT J AU Broadhurst, T Benitez, N Coe, D Sharon, K Zekser, K White, R Ford, H Bouwens, R Blakeslee, J Clampin, M Cross, N Franx, M Frye, B Hartig, G Illingworth, G Infante, L Menanteau, F Meurer, G Postman, M Ardila, DR Bartko, F Brown, RA Burrows, CJ Cheng, ES Feldman, PD Golimowski, DA Goto, T Gronwall, C Herranz, D Holden, B Homeier, N Krist, JE Lesser, MP Martel, AR Miley, GK Rosati, P Sirianni, M Sparks, WB Steindling, S Tran, HD Tsvetanov, ZI Zheng, W AF Broadhurst, T Benitez, N Coe, D Sharon, K Zekser, K White, R Ford, H Bouwens, R Blakeslee, J Clampin, M Cross, N Franx, M Frye, B Hartig, G Illingworth, G Infante, L Menanteau, F Meurer, G Postman, M Ardila, DR Bartko, F Brown, RA Burrows, CJ Cheng, ES Feldman, PD Golimowski, DA Goto, T Gronwall, C Herranz, D Holden, B Homeier, N Krist, JE Lesser, MP Martel, AR Miley, GK Rosati, P Sirianni, M Sparks, WB Steindling, S Tran, HD Tsvetanov, ZI Zheng, W TI Strong-lensing analysis of A1689 from deep Advanced Camera images SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmological parameters; galaxies : clusters : individual (A1683); gravitational lensing ID HUBBLE-SPACE-TELESCOPE; DARK-MATTER HALOS; X-RAY; MASS-DISTRIBUTION; BACKGROUND GALAXIES; DENSITY PROFILES; INNER STRUCTURE; CLUSTER SURVEY; RICH CLUSTERS; HIGH-REDSHIFT AB We analyze deep multicolor Advanced Camera images of the largest known gravitational lens, A1689. Radial and tangential arcs delineate the critical curves in unprecedented detail, and many small counterimages are found near the center of mass. We construct a flexible light deflection field to predict the appearance and positions of counterimages. The model is refined as new counterimages are identified and incorporated to improve the model, yielding a total of 106 images of 30 multiply lensed background galaxies, spanning a wide redshift range, 1.0 < z < 5.5. The resulting mass map is more circular in projection than the clumpy distribution of cluster galaxies, and the light is more concentrated than the mass within r < 50 kpc h(-1). The projected mass profile flattens steadily toward the center with a shallow mean slope of dlog &USigma;/dlog r &SIME; -0.55 &PLUSMN; 0.1, over the observed range r < 250 kpc h(-1), matching well an NFW profile, but with a relatively high concentration, C-vir = 8.2(1.8)(+2.1). A softened isothermal profile (r(core) = 20 +/- 2") is not conclusively excluded, illustrating that lensing constrains only projected quantities. Regarding cosmology, we clearly detect the purely geometric increase of bend angles with redshift. The dependence on the cosmological parameters is weak owing to the proximity of A1689, z = 0.18, constraining the locus, Omega(M) + Omega(Lambda) less than or equal to 1.2. This consistency with standard cosmology provides independent support for our model, because the redshift information is not required to derive an accurate mass map. Similarly, the relative fluxes of the multiple images are reproduced well by our best-fitting lens model. C1 Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. CSIC, Inst Astrofis Andalucia, E-18008 Granada, Spain. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Conceptual Anal LLC, Glenn Dale, MD 20769 USA. Princeton Univ, Princeton, NJ 08544 USA. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile. Bartko Sci & Technol, Brighton, CO 80602 USA. Leiden Observ, NL-2300 RA Leiden, Netherlands. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Ist Sci & Tecnol Informaz Alessandro Faedo, I-56124 Pisa, Italy. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. European So Observ, D-85748 Garching, Germany. WM Keck Observ, Kamuela, HI 96743 USA. RP Broadhurst, T (reprint author), Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel. EM tjb@wise3.tau.ac.il RI Clampin, mark/D-2738-2012; Herranz, Diego/K-9143-2014; OI Herranz, Diego/0000-0003-4540-1417; tran, hien/0000-0001-7548-6664; Menanteau, Felipe/0000-0002-1372-2534; Benitez, Narciso/0000-0002-0403-7455; Blakeslee, John/0000-0002-5213-3548 NR 81 TC 215 Z9 215 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 MAR 1 PY 2005 VL 621 IS 1 BP 53 EP 88 DI 10.1086/426494 PN 1 PG 36 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200006 ER PT J AU Cillis, AN Torres, DF Reimer, O AF Cillis, AN Torres, DF Reimer, O TI EGRET upper limits and stacking searches of gamma-ray observations of luminous and ultraluminous infrared galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : starburst; gamma rays : observations ID STAR-FORMATION; EMISSION AB We present a stacking analysis of EGRET gamma-ray observations at the positions of luminous and ultraluminous infrared galaxies. The latter were selected from the recently presented HCN survey, which is thought to contain the most active star-forming regions of the universe. Different sorting criteria are used, and since there is no positive collective detection of gamma-ray emission from these objects, we determined both collective and individual upper limits. The uppermost excess we find appears in the case of ULIRGs ordered by redshift, at a value of 1.8 sigma. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. SP Syst Inc, Lanham, MD USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Ruhr Univ Bochum, Inst Theoret Phys 4, D-44780 Bochum, Germany. RP Cillis, AN (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. EM cillis@blazar.gsfc.nasa.gov; dtorres@igpp.ucllnl.org; olr@tp4.ruhr-uni-bochum.de RI Reimer, Olaf/A-3117-2013; Torres, Diego/O-9422-2016 OI Reimer, Olaf/0000-0001-6953-1385; Torres, Diego/0000-0002-1522-9065 NR 16 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 MAR 1 PY 2005 VL 621 IS 1 BP 139 EP 145 DI 10.1086/427496 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200012 ER PT J AU Daniel, MK Badran, HM Bond, IH Boyle, PJ Bradbury, SM Buckley, JH Carter-Lewis, DA Catanese, M Celik, O Cogan, P Cui, W D'Vali, M Perez, ID Duke, C Falcone, A Fegan, DJ Fegan, SJ Finley, JP Fortson, LF Gaidos, JA Gammell, S Gibbs, K Gillanders, GH Grube, J Hall, J Hall, TA Hanna, D Hillas, AM Holder, J Horan, D Humensky, TB Jarvis, A Jordan, M Kenny, GE Kertzman, M Kieda, D Kildea, J Knapp, J Kosack, K Krawczynski, H Krennrich, F Lang, MJ Le Bohec, S Linton, E Lloyd-Evans, J Milovanovic, A Moriarty, P Muller, D Nagai, T Nolan, S Ong, RA Pallassini, R Petry, D Power-Mooney, B Quinn, J Quinn, M Ragan, K Rebillot, P Reynolds, PT Rose, HJ Schroedter, M Sembroski, GH Swordy, SP Syson, A Vassiliev, VV Wakely, SP Walker, G Weekes, TC Zweerink, J AF Daniel, MK Badran, HM Bond, IH Boyle, PJ Bradbury, SM Buckley, JH Carter-Lewis, DA Catanese, M Celik, O Cogan, P Cui, W D'Vali, M Perez, ID Duke, C Falcone, A Fegan, DJ Fegan, SJ Finley, JP Fortson, LF Gaidos, JA Gammell, S Gibbs, K Gillanders, GH Grube, J Hall, J Hall, TA Hanna, D Hillas, AM Holder, J Horan, D Humensky, TB Jarvis, A Jordan, M Kenny, GE Kertzman, M Kieda, D Kildea, J Knapp, J Kosack, K Krawczynski, H Krennrich, F Lang, MJ Le Bohec, S Linton, E Lloyd-Evans, J Milovanovic, A Moriarty, P Muller, D Nagai, T Nolan, S Ong, RA Pallassini, R Petry, D Power-Mooney, B Quinn, J Quinn, M Ragan, K Rebillot, P Reynolds, PT Rose, HJ Schroedter, M Sembroski, GH Swordy, SP Syson, A Vassiliev, VV Wakely, SP Walker, G Weekes, TC Zweerink, J TI Spectrum of very high energy gamma-rays from the blazar 1ES 1959+650 during flaring activity in 2002 SO ASTROPHYSICAL JOURNAL LA English DT Article DE BL Lacertae objects : individual (1ES 1959+650); gamma rays : observations; techniques : spectroscopic ID CHERENKOV TELESCOPES; STRONG FLARES; TEV ENERGIES; RADIATION; SYSTEM; MARKARIAN-421; CALIBRATION; H1426+428; PROJECT AB The blazar 1ES 1959+650 was observed in a flaring state with the Whipple 10 m Imaging Atmospheric Cerenkov Telescope in 2002 May. A spectral analysis has been carried out on the data from that time period, and the resulting very high energy gamma-ray spectrum (E greater than or equal to 316 GeV) can be well fitted by a power law of differential spectral index alpha = 2.78 +/- 0.12(stat) +/- 0.21(sys). On 2002 June 4, the source flared dramatically in the gamma-ray range without any coincident increase in the X-ray emission, providing the first unambiguous example of an "orphan'' gamma-ray flare from a blazar. The gamma-ray spectrum for these data can also be described by a simple power-law fit with alpha = 2.82 +/- 0.15(stat) +/- 0.30(sys). There is no compelling evidence for spectral variability or for any cutoff to the spectrum. C1 Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Tanta Univ, Dept Phys, Tanta, Egypt. Univ Leeds, Dept Phys, Leeds LS2 9JT, W Yorkshire, England. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Harvard Smithsonian Ctr Astrophys, Fred Lawrence Whipple Observ, Amado, AZ 85645 USA. Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. Natl Univ Ireland, Expt Phys Dept, Dublin 4, Ireland. Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Grinnell Coll, Dept Phys, Grinnell, IA 50112 USA. Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. Natl Univ Ireland, Dept Phys, Galway, Ireland. Univ Utah, High Energy Astrophys Inst, Salt Lake City, UT USA. Univ Arkansas, Dept Phys & Astron, Little Rock, AR 72204 USA. McGill Univ, Dept Phys, Montreal, PQ H3A 2T8, Canada. Depauw Univ, Dept Phys & Astron, Greencastle, IN 46135 USA. Galway Mayo Inst Technol, Sch Sci, Galway, Ireland. Univ Maryland Baltimore Cty, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Colk Inst Technol, Dept Appl Phys & Instrumentat, Cork, Ireland. RP Daniel, MK (reprint author), Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. EM mkdaniel@iastate.edu RI Hall, Jeter/E-9294-2015; Daniel, Michael/A-2903-2010; OI Daniel, Michael/0000-0002-8053-7910; Cui, Wei/0000-0002-6324-5772; Knapp, Johannes/0000-0003-1519-1383; Lang, Mark/0000-0003-4641-4201 NR 32 TC 28 Z9 28 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 MAR 1 PY 2005 VL 621 IS 1 BP 181 EP 187 DI 10.1086/427406 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200016 ER PT J AU Goto, T Postman, M Cross, NJG Illingworth, GD Tran, K Magee, D Franx, M Benitez, N Bouwens, RJ Demarco, R Ford, HC Homeier, NL Martel, AR Menanteau, F Clampin, M Hartig, GF Ardila, DR Bartko, F Blakeslee, JP Bradley, LD Broadhurst, TJ Brown, RA Burrows, CJ Cheng, ES Feldman, PD Golimowski, DA Gronwall, C Holden, B Infante, L Jee, MJ Krist, JE Lesser, MP Mei, S Meurer, GR Miley, GK Motta, V Overzier, R Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W Zirm, A AF Goto, T Postman, M Cross, NJG Illingworth, GD Tran, K Magee, D Franx, M Benitez, N Bouwens, RJ Demarco, R Ford, HC Homeier, NL Martel, AR Menanteau, F Clampin, M Hartig, GF Ardila, DR Bartko, F Blakeslee, JP Bradley, LD Broadhurst, TJ Brown, RA Burrows, CJ Cheng, ES Feldman, PD Golimowski, DA Gronwall, C Holden, B Infante, L Jee, MJ Krist, JE Lesser, MP Mei, S Meurer, GR Miley, GK Motta, V Overzier, R Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W Zirm, A TI Luminosity functions of the galaxy cluster MS 1054-0321 at z=0.83 based on ACS photometry SO ASTROPHYSICAL JOURNAL LA English DT Review DE galaxies : clusters : general; galaxies : clusters : individual (Cl 1056-03, MS 1054-0321) ID HUBBLE-SPACE-TELESCOPE; DIGITAL SKY SURVEY; MORPHOLOGY-DENSITY RELATION; BUTCHER-OEMLER CLUSTERS; COMPACT DWARF GALAXIES; HIGH-REDSHIFT CLUSTERS; STAR-FORMATION RATE; DEEP FIELD-NORTH; X-RAY DATA; RICH CLUSTERS AB We present new measurements of the galaxy luminosity function (LF) and its dependence on local galaxy density, color, morphology, and clustocentric radius for the massive z = 0.83 cluster MS 1054-0321. Our analyses are based on imaging performed with the Advanced Camera for Surveys (ACS) on board the Hubble Space Telescope (HST) in the F606W, F775W, and F850LP passbands and extensive spectroscopic data obtained with the Keck Low-Resolution Imaging Spectrograph. Our main results are based on a spectroscopically selected sample of 143 cluster members with morphological classifications derived from the ACS observations. Our three primary findings are (1) the faint-end slope of the LF is steepest in the bluest filter, (2) the LF in the inner part of the cluster (or highest density regions) has a flatter faint-end slope, and (3) the fraction of early-type galaxies is higher at the bright end of the LF, and gradually decreases toward fainter magnitudes. These characteristics are consistent with those in local galaxy clusters, indicating that, at least in massive clusters, the common characteristics of cluster LFs are established at z = 0.83. These results provide additional support for the hypothesis that the formation of galaxies in MS 1054-0321 began at redshifts considerably greater than unity. We also find a 2 sigma deficit of intrinsically faint, red galaxies (i(775)-z(850) greater than or equal to 0.5, M-i > -19) in this cluster. Although the significance is marginal, this trend may suggest that faint, red galaxies (which are common in z < 0.1 rich clusters) have not yet been created in this cluster at z = 0.83. The giant-to-dwarf ratio in MS 1054-0321 starts to increase inwards of the virial radius or when &USigma; > 30 Mpc(-2), coinciding with the environment where the galaxy star formation rate and the morphology-density relation start to appear. A physical process that begins to become effective at around the virial radius or Sigma similar to 30 Mpc(-2) may thus be responsible for the evolution of color and luminosity of cluster galaxies. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. ETH Honggerberg, Astron Inst, CH-8093 Zurich, Switzerland. Leiden Observ, NL-2300 RA Leiden, Netherlands. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Bartko Sci & Technol, Mead, CO 80542 USA. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Conceptual Anal LLC, Glenn Dale, MD 20769 USA. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. European So Observ, D-85748 Garching, Germany. WM Keck Observ, Kamuela, HI 96743 USA. RP Goto, T (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. RI Clampin, mark/D-2738-2012; OI Benitez, Narciso/0000-0002-0403-7455; Blakeslee, John/0000-0002-5213-3548 NR 132 TC 38 Z9 38 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 2005 VL 621 IS 1 BP 188 EP 200 DI 10.1086/427492 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200017 ER PT J AU McCrady, N Graham, JR Vacca, WD AF McCrady, N Graham, JR Vacca, WD TI Mass segregation and the initial mass function of super star cluster M82-F SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (M82); galaxies : star clusters; galaxies : starburst; infrared : galaxies ID LARGE-MAGELLANIC-CLOUD; STELLAR CLUSTERS; GLOBULAR-CLUSTERS; DYNAMICAL MASSES; STARBURST; EVOLUTION; NGC-4038/4039; ULTRAVIOLET; NGC-1705; HST AB We investigate the initial mass function and mass segregation in super star cluster M82-F with high-resolution Keck NIRSPEC echelle spectroscopy. Cross-correlation with template supergiant spectra provides the velocity dispersion of the cluster, enabling measurement of the kinematic (virial) mass of the cluster when combined with sizes from NICMOS and Advanced Camera for Surveys (ACS) images. We find a mass of 6.6 +/- 0.9 x 10(5) M-circle dot based on near-IR light and 7.0 +/- 1.2 x 10(5) M-circle dot based on optical light. Using PSF-fitting photometry, we derive the cluster's light-to-mass (L/M) ratio in both near-IR and optical light and compare to population-synthesis models. The ratios are inconsistent with a normal stellar initial mass function for the adopted age of 40-60 Myr, suggesting a deficiency of low-mass stars within the volume sampled. King model light profile fits to new Hubble Space Telescope ACS images of M82-F, in combination with fits to archival near-IR images, indicate mass segregation in the cluster. As a result, the virial mass represents a lower limit on the mass of the cluster. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP McCrady, N (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. EM nate@astro.berkeley.edu NR 43 TC 43 Z9 45 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 MAR 1 PY 2005 VL 621 IS 1 BP 278 EP 284 DI 10.1086/427487 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200024 ER PT J AU Cillis, AN Hartman, RC AF Cillis, AN Hartman, RC TI EGRET diffuse gamma-ray maps between 30 MeV and 10 GeV SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic rays; diffuse radiation; gamma rays : observations ID RADIO-LOUD AGN; GALACTIC PLANE; COSMIC-RAY; EXPERIMENT TELESCOPE; SAS-2 OBSERVATIONS; RADIATION; ASTRONOMY; EMISSION; CALIBRATION; SATELLITE AB This paper presents all-sky maps of diffuse gamma radiation in various energy ranges between 30 MeV and 10 GeV, based on data collected by the EGRET instrument on the Compton Gamma Ray Observatory (CGRO). Although the maps can be used for a variety of applications, the immediate goal is the generation of diffuse gamma-ray maps, which can be used as a diffuse background/foreground for point-source analysis of the data to be obtained from new high-energy gamma-ray missions such as GLAST and AGILE. To generate the diffuse gamma maps from the raw EGRET maps, the point sources in the Third EGRET Catalog were subtracted out using the appropriate point-spread function for each energy range. After that, smoothing was performed to minimize the effects of photon statistical noise. A smoothing length of 1degrees was used for the Galactic plane maps. For the all-sky maps, a procedure was used that resulted in a smoothing length roughly equivalent to 4degrees. The result of this work is 16 maps of different energy intervals for \b\ less than or equal to 20degrees and 32 all-sky maps, 16 in equatorial coordinates (J2000.0) and 16 in Galactic coordinates. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Cillis, AN (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. NR 37 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 MAR 1 PY 2005 VL 621 IS 1 BP 291 EP 295 DI 10.1086/427402 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200026 ER PT J AU Teegarden, BJ Watanabe, K Jean, P Knodlseder, J Lonjou, V Roques, JP Skinner, GK von Ballmoos, P Weidenspointner, G Bazzano, A Butt, YM Decourchelle, A Fabian, AC Goldwurm, A Gudel, M Hannikainen, DC Hartmann, DH Hornstrup, A Lewin, WHG Makishima, K Malzac, A Miller, J Parmar, AN Reynolds, SP Rothschild, RE Schonfelder, V Tomsick, JA Vink, J AF Teegarden, BJ Watanabe, K Jean, P Knodlseder, J Lonjou, V Roques, JP Skinner, GK von Ballmoos, P Weidenspointner, G Bazzano, A Butt, YM Decourchelle, A Fabian, AC Goldwurm, A Gudel, M Hannikainen, DC Hartmann, DH Hornstrup, A Lewin, WHG Makishima, K Malzac, A Miller, J Parmar, AN Reynolds, SP Rothschild, RE Schonfelder, V Tomsick, JA Vink, J TI INTEGRAL SPI limits on electron-positron annihilation radiation from the Galactic plane SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : observations ID 511 KEV LINE; CENTER REGION; CENTER DIRECTION; INNER GALAXY; EMISSION AB The center of our Galaxy is a known strong source of electron-positron 511 keVannihilation radiation. Thus far, however, there have been no reliable detections of annihilation radiation outside of the central radian of our Galaxy. One of the primary objectives of the INTEGRAL ( International Gamma-Ray Astrophysics Laboratory) mission, launched in 2002 October, is the detailed study of this radiation. The Spectrometer on INTEGRAL (SPI) is a high-resolution, coded-aperture gamma-ray telescope with an unprecedented combination of sensitivity, angular resolution, and energy resolution. We report results from the first 10 months of observation. During this period a significant fraction of the observing time was spent in or near the Galactic plane. No positive annihilation flux was detected outside of the central region (\l\> 40degrees) of our Galaxy. In this paper we describe the observations and data analysis methods and give limits on the 511 keV flux. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. CNRS, UPS, Ctr Etud Spatiale Rayonnements, F-31028 Toulouse 4, France. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. CE Saclay, Serv Astrophys, F-91191 Gif Sur Yvette, France. Ist Astrofis Spaziale & Fis Cosm, IASF, Rome, Italy. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Univ Helsinki, FIN-00014 Helsinki, Finland. Clemson Univ, Clemson, SC 29634 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan. European Space Agcy, Estec, Div Astrophys, Res & Sci Support Dept, NL-2200 AG Noordwijk, Netherlands. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. Max Planck Inst Extraterr Phys, D-85740 Garching, Germany. SRON, Natl Inst Space Res, NL-3584 CA Utrecht, Netherlands. RP NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. RI Guedel, Manuel/C-8486-2015; OI Guedel, Manuel/0000-0001-9818-0588; Parmar, Arvind/0000-0002-3307-6517; Bazzano, Angela/0000-0002-2017-4396 NR 33 TC 49 Z9 50 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 MAR 1 PY 2005 VL 621 IS 1 BP 296 EP 300 DI 10.1086/426859 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200027 ER PT J AU Davis, SW Blaes, OM Hubeny, I Turner, NJ AF Davis, SW Blaes, OM Hubeny, I Turner, NJ TI Relativistic accretion disk models of high-state black hole X-ray binary spectra SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; radiative transfer; X-rays : binaries ID ACTIVE GALACTIC NUCLEI; NON-LTE MODELS; MARGINALLY STABLE ORBIT; THEORETICAL SPECTRA; VERTICAL STRUCTURE; LMC X-1; RADIATION; EVOLUTION; COMPTONIZATION; INSTABILITIES AB We present calculations of non-LTE, relativistic accretion disk models applicable to the high/soft state of black hole X-ray binaries. We include the effects of thermal Comptonization and bound-free and free-free opacities of all abundant ion species. Taking into account the relativistic propagation of photons from the local disk surface to an observer at infinity, we present spectra calculated for a variety of accretion rates, black hole spin parameters, disk inclinations, and stress prescriptions. We also consider nonzero inner torques on the disk and explore different vertical dissipation profiles, including some that are motivated by recent radiation magnetohydrodynamic (MHD) simulations of magnetorotational turbulence. Bound-free metal opacity generally produces significantly less spectral hardening than previous models that only considered Compton scattering and free-free opacity. We find that the resulting effective photosphere usually lies at a small fraction of the total column depth, producing spectra that are remarkably independent of the stress prescription and vertical structure assumptions. We provide detailed comparisons between our models and the widely used multicolor disk model. Frequency-dependent discrepancies exist that may affect the parameters of other spectral components when this simpler disk model is used to fit modern X-ray data. For a given source, our models predict that the luminosity in the high/soft state should approximately scale with the fourth power of the empirically inferred maximum temperature, but with a slight hardening at high luminosities. This is in good agreement with observations. C1 Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Arizona, Dept Astron, Tucson, AZ 85721 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Davis, SW (reprint author), Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. OI Turner, Neal/0000-0001-8292-1943 NR 50 TC 143 Z9 145 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 MAR 1 PY 2005 VL 621 IS 1 BP 372 EP 387 DI 10.1086/427278 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200034 ER PT J AU Wachter, S Wellhouse, JW Patel, SK Smale, AP Alves, JF Bouchet, P AF Wachter, S Wellhouse, JW Patel, SK Smale, AP Alves, JF Bouchet, P TI Chandra HRC localization of the low-mass X-ray binaries X1624-490 and X1702-429: The infrared counterparts SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars : neutron; X-rays : binaries; X-rays : individual (4U 1624-490, 4U 1702-429) ID SCORPIUS X-1; 4U 1702-42; SPECTROSCOPY; ULTRAVIOLET; BURSTS AB We report on the precise localization of the low-mass X-ray binaries X1624 - 490 and X1702 - 429 with the Chandra HRC-I. We determine the best positions to be 16(h)28(m)02.(s) 825, - 49degrees11'54."61 and 17(h)06(m)15.(s)314, - 43degrees02'08."69 (J2000.0) for X1624 - 490 and X1702 - 429, respectively, with the nominal Chandra positional uncertainty of 0."6. We also obtained deep IR observations of the fields of these sources in an effort to identify the IR counterparts. A single, faint (K-s = 18.3 +/- 0.1) source is visible inside the Chandra error circle of X1624 - 490, and we propose this source as its IR counterpart. For X1702 - 429, a K-s = 16.5 +/- 0.07 source is visible at the edge of the Chandra error circle. The brightness of both counterpart candidates is comparable to that of other low-mass X-ray binary IR counterparts when corrected for extinction and distance. C1 CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. Harvey Mudd Coll, Claremont, CA 91711 USA. Univ Space Res Assoc, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Univ Space Res Assoc, Greenbelt, MD 20771 USA. European So Observ, D-85748 Garching, Germany. Natl Opt Astron Observ, Cerro Tololo Inter Amer Observ, La Serena, Chile. Eureka Sci Inc, Oakland, CA 94602 USA. RP Wachter, S (reprint author), CALTECH, Spitzer Sci Ctr, MS 220-6, Pasadena, CA 91125 USA. EM wachter@ipac.caltech.edu; Sandeep.Patel@msfc.nasa.gov; alan@osiris.gsfc.nasa.gov; jalves@eso.org; pbouchet@noao.edu OI Alves, Joao/0000-0002-4355-0921 NR 21 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 MAR 1 PY 2005 VL 621 IS 1 BP 393 EP 397 DI 10.1086/427407 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200036 ER PT J AU D'Alessio, P Hartmann, L Calvet, N Franco-Hernandez, R Forrest, WJ Sargent, B Furlan, E Uchida, K Green, JD Watson, DM Chen, CH Kemper, F Sloan, GC Najita, J AF D'Alessio, P Hartmann, L Calvet, N Franco-Hernandez, R Forrest, WJ Sargent, B Furlan, E Uchida, K Green, JD Watson, DM Chen, CH Kemper, F Sloan, GC Najita, J TI The truncated disk of CoKu Tau/4 SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared : stars; planetary systems : formation; planetary systems : protoplanetary disks; stars : pre-main-sequence ID T-TAURI STARS; AURIGA MOLECULAR CLOUD; INTERSTELLAR SILICATE MINERALOGY; MAIN-SEQUENCE EVOLUTION; ACCRETION DISKS; YOUNG OBJECTS; CIRCUMSTELLAR DISKS; HYDRAE ASSOCIATION; OPTICAL-PROPERTIES; MASS STARS AB We present a model of a dusty disk with an inner hole that accounts for the Spitzer Space Telescope Infrared Spectrograph observations of the low-mass pre-main-sequence star CoKu Tau/4. We have modeled the mid-infrared spectrum ( between 8 and 25 mum) as arising from the inner wall of a disk. Our model disk has an evacuated inner zone of radius similar to 10 AU, with a dusty inner "wall'' of half- height similar to 2 AU that is illuminated at normal incidence by the central star. The radiative equilibrium temperature decreases from the inner disk edge outward through the optically thick disk; this temperature gradient is responsible for the emission of the silicate bands at 10 and 20 mum. The observed spectrum is consistent with being produced by Fe-Mg amorphous glassy olivine and/or pyroxene, with no evidence of a crystalline component. The mid-infrared spectrum of CoKu Tau/4 is reminiscent of that of the much older star TW Hya, where it has been suggested that the significant clearing of its inner disk is due to planet formation. However, no inner disk remains in CoKu Tau/4, consistent with the star being a weak-emission (nonaccreting) T Tauri star. The relative youth of CoKu Tau/4 ( similar to 1 Myr) may indicate much more rapid planet formation than typically assumed. C1 Ctr Radioastron & Astrofis, Morelia 58089, Michoacan, Mexico. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Natl Opt Astron Observ, Tucson, AZ 85719 USA. RP D'Alessio, P (reprint author), Ctr Radioastron & Astrofis, Apdo Postal 72-3 Xangari, Morelia 58089, Michoacan, Mexico. EM p.dalessio@astrosmo.unam.mx RI Kemper, Francisca/D-8688-2011; OI Kemper, Francisca/0000-0003-2743-8240; Furlan, Elise/0000-0001-9800-6248 NR 55 TC 165 Z9 165 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 MAR 1 PY 2005 VL 621 IS 1 BP 461 EP 472 DI 10.1086/427490 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200042 ER PT J AU Veronig, AM Brown, JC Dennis, BR Schwartz, RA Sui, L Tolbert, AK AF Veronig, AM Brown, JC Dennis, BR Schwartz, RA Sui, L Tolbert, AK TI Physics of the Neupert effect: Estimates of the effects of source energy, mass transport, and geometry using RHESSI and GOES data SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : flares; Sun : X-rays, gamma rays ID HARD X-RAY; CHROMOSPHERIC EVAPORATION MODEL; SOLAR-FLARE LOOPS; 20 FEBRUARY 2002; EMISSION MEASURE; LINE EMISSION; JULY 23; BREMSSTRAHLUNG; SPECTRA; TARGET AB The "empirical Neupert effect'' (ENE) is the observed temporal correlation of the hard X-ray (HXR) flux F-HXR(t) with the time derivative of the soft X-ray (SXR) flux. (F) over dot(SXR)( t) in many flares. This is widely taken to mean that the energetic electrons responsible for F-HXR( t) by thick-target collisional bremsstrahlung are the main source of heating and mass supply ( via chromospheric evaporation) of the SXR-emitting hot coronal plasma. If this interpretation were correct, one would expect better correlation between the beam power supply P-beam(t), inferred from the HXR spectrum, and the actual power P-in( t) required to explain the SXR flux and spectrum, allowing for variations in both emission measure (EM) and temperature T, for radiative and conductive cooling losses, and for complexities of geometry like multiple loops. We call this the "theoretical Neupert effect'' (TNE). To test if it is true that P-beam(t) and P-in( t) inferred from data are better correlated than F-HXR( t) and. (F) over dot (SXR)( t), we use an approximate approach for a simple single-loop geometry and rough estimates of the particle and energy transport and apply the model to RHESSI and GOES data on four flares. We find that if the beam low cutoff energy E-1 is taken as constant, the correlation of P-beam( t), P-in( t) is no better than that of F-HXR( t);. (F) over dot(SXR)( t). While our modeling contains many approximations to cooling and other physics, ignored entirely from ENE data considerations, there seems to be no reason why their order-of-magnitude inclusion should make the TNE worse rather than better, although this should be checked by more accurate simulations. These results suggest that one or more of the following must be true: ( 1) fast electrons are not the main source of SXR plasma supply and heating, ( 2) the beam low cutoff energy varies with time, or ( 3) the TNE is strongly affected by source geometry. These options are discussed in relation to possible future directions for TNE research. C1 Graz Univ, Inst Geophys Astrophys & Meteorol, A-8010 Graz, Austria. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Glasgow, Dept Phys & Astron, Astron & Astrophys Grp, Glasgow G12 8QQ, Lanark, Scotland. Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Veronig, AM (reprint author), Graz Univ, Inst Geophys Astrophys & Meteorol, A-8010 Graz, Austria. RI Dennis, Brian/C-9511-2012; Veronig, Astrid/B-8422-2009 NR 62 TC 93 Z9 94 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 MAR 1 PY 2005 VL 621 IS 1 BP 482 EP 497 DI 10.1086/427274 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200044 ER PT J AU Rust, DM Anderson, BJ Andrews, MD Acuna, MH Russell, CT Schuck, PW Mulligan, T AF Rust, DM Anderson, BJ Andrews, MD Acuna, MH Russell, CT Schuck, PW Mulligan, T TI Comparison of interplanetary disturbances at the NEAR spacecraft with coronal mass ejections at the Sun SO ASTROPHYSICAL JOURNAL LA English DT Article DE interplanetary medium; Sun : coronal mass ejections (CMEs); Sun : particle emission ID HELICAL MAGNETIC-FIELDS; FLUX-ROPES; SOLAR-WIND; CLOUDS; FILAMENTS; ULYSSES; LASCO; STREAMER; ORIGIN; SOHO AB We examined interplanetary (IP) magnetic field disturbances recorded by the Near Earth Asteroid Rendezvous Shoemaker spacecraft ( NEAR) when it was above either the east or west solar limb as seen from Earth; we then identified the associated coronal mass ejections (CMEs) detected above the limbs by the SOHO LASCO coronagraph. We found 10 cases in which a nonrecurring IP disturbance could be associated with a CME. Eight of the disturbances included a magnetic flux rope signature. Flux rope chirality and axis orientation were determined for each one and compared with chirality and axis orientation at the Sun, as inferred from flux rope signatures filaments and sigmoids - that could be associated with the CMEs. In most cases, the chirality and orientation inferred from these preeruption flux rope signatures agreed well with the flux rope signatures at NEAR. These results suggest, in agreement with Plunkett and coworkers, that the flux ropes existed prior to eruption and that the flux ropes on the Sun become flux ropes in IP space. Comparisons of the CME speeds to the time-of-flight average speeds showed that flux ropes are less accelerated or decelerated by the solar wind than are the CME leading edges. These results imply that the faint features or loops that make up the CME leading edges are probably distinct from the flux ropes. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. USN, Res Lab, Computat Phys Inc, Washington, DC 20375 USA. NASA, Goddard Space Flight Ctr, Planetary Magnetospheres Branch, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Inst Geophys, Los Angeles, CA 90095 USA. USN, Res Lab, Div Plasma Phys, Washington, DC 20375 USA. Aerosp Corp, Dept Space Sci, El Segundo, CA 90245 USA. RP Rust, DM (reprint author), Johns Hopkins Univ, Appl Phys Lab, 11100 Johns Hopkins Rd, Laurel, MD 20723 USA. RI Anderson, Brian/I-8615-2012; OI Russell, Christopher/0000-0003-1639-8298 NR 53 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 MAR 1 PY 2005 VL 621 IS 1 BP 524 EP 536 DI 10.1086/427401 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200047 ER PT J AU Dello Russo, N Bonev, BP DiSanti, MA Mumma, MJ Gibb, EL Magee-Sauer, K Barber, RJ Tennyson, J AF Dello Russo, N Bonev, BP DiSanti, MA Mumma, MJ Gibb, EL Magee-Sauer, K Barber, RJ Tennyson, J TI Water production rates, rotational temperatures, and spin temperatures in comets C/1999 H1 (Lee), C/1999 S4, and C/2001 A2 SO ASTROPHYSICAL JOURNAL LA English DT Article DE comets : general; comets : individual (C/1999 S4, C/2001 A2, Lee (C/1999 H1)); infrared : solar system; techniques : spectroscopic ID O1 HALE-BOPP; B2 HYAKUTAKE; CARBON-MONOXIDE; HYDROGEN-CYANIDE; H1 LEE; RELEASE; SPECTRA; METHANE; ETHANE; VAPOR AB Water hot-band lines were detected in comets C/1999 H1 ( Lee), C/1999 S4 ( LINEAR), and C/2001 A2 ( LINEAR) in the 2.9 mum spectral region using high-dispersion (lambda/Deltalambda similar to 2 x 10(4)) infrared spectroscopy with NIRSPEC at the W. M. Keck Observatory. The density of H2O emissions in this spectral region, the spectral coverage and resolution of NIRSPEC, and fluorescence models developed for these hot bands enabled the determination of H2O production rates, rotational temperatures, and ortho-to-para ratios (OPRs) in these comets. Previous studies revealed clear diversity in the volatile organic chemistries of these comets, suggesting that they may have formed in different regions of the early solar nebula. The nuclear spin temperature of H2O as derived from its OPR is another possible indicator of cometary formation temperature and region. Nuclear spin temperatures for H2O were derived on one date in comet S4 and two dates in Lee and A2. Derived spin temperatures for H2O in these comets are greater than or equal to30, 30(-6)(+15), and 23(-3)(+4) K for S4, Lee, and A2, respectively. Measurements are consistent with a possible link between nuclear spin temperatures and volatile abundances, but studies of more comets and continued improvements in water hot-band fluorescence models are needed to more stringently test this. C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Toledo, Dept Phys & Astron, Ritter Astrophys Res Ctr, Toledo, OH 43606 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Rowan Univ, Dept Chem & Phys, Glassboro, NJ 08028 USA. UCL, Dept Phys & Astron, London WC1E 6BT, England. RP Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RI Tennyson, Jonathan/I-2222-2012; mumma, michael/I-2764-2013; Magee-Sauer, Karen/K-6061-2015; Dello Russo, Neil/G-2727-2015 OI Tennyson, Jonathan/0000-0002-4994-5238; Magee-Sauer, Karen/0000-0002-4979-9875; Dello Russo, Neil/0000-0002-8379-7304 NR 57 TC 79 Z9 79 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 MAR 1 PY 2005 VL 621 IS 1 BP 537 EP 544 DI 10.1086/427473 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200048 ER PT J AU Gehrels, N Chincarini, G Giommi, P Mason, KO Nousek, JA Wells, AA White, NE Barthelmy, SD Burrows, DN Cominsky, LR Hurley, KC Marshall, FE Meszaros, P Roming, PWA Angelini, L Barbier, LM Belloni, T Boyd, PT Campana, S Caraveo, PA Chester, MM Citterio, O Cline, TL Cropper, MS Cummings, JR Dean, AJ Feigelson, ED Fenimore, EE Frail, DA Fruchter, AS Garmire, GP Gendreau, K Ghisellini, G Greiner, J Hill, JE Hunsberger, SD Krimm, HA Kulkarni, SR Kumar, P Lebrun, F Lloyd-Ronning, NM Markwardt, CB Mattson, BJ Mushotzky, RF Norris, JP Paczynski, B Palmer, DM Park, HS Parsons, AM Paul, J Rees, MJ Reynolds, CS Rhoads, JE Sasseen, TP Schaefer, BE Short, AT Smale, AP Smith, IA Stella, L Still, M Tagliaferri, G Takahashi, T Tashiro, M Townsley, LK Tueller, J Turner, MJL Vietri, M Voges, W Ward, MJ Willingale, R Zerbi, FM Zhang, WW AF Gehrels, N Chincarini, G Giommi, P Mason, KO Nousek, JA Wells, AA White, NE Barthelmy, SD Burrows, DN Cominsky, LR Hurley, KC Marshall, FE Meszaros, P Roming, PWA Angelini, L Barbier, LM Belloni, T Boyd, PT Campana, S Caraveo, PA Chester, MM Citterio, O Cline, TL Cropper, MS Cummings, JR Dean, AJ Feigelson, ED Fenimore, EE Frail, DA Fruchter, AS Garmire, GP Gendreau, K Ghisellini, G Greiner, J Hill, JE Hunsberger, SD Krimm, HA Kulkarni, SR Kumar, P Lebrun, F Lloyd-Ronning, NM Markwardt, CB Mattson, BJ Mushotzky, RF Norris, JP Paczynski, B Palmer, DM Park, HS Parsons, AM Paul, J Rees, MJ Reynolds, CS Rhoads, JE Sasseen, TP Schaefer, BE Short, AT Smale, AP Smith, IA Stella, L Still, M Tagliaferri, G Takahashi, T Tashiro, M Townsley, LK Tueller, J Turner, MJL Vietri, M Voges, W Ward, MJ Willingale, R Zerbi, FM Zhang, WW TI The swift gamma-ray burst mission (vol 611, pg 1005, 2004) SO ASTROPHYSICAL JOURNAL LA English DT Correction C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Osserv Astron Brera, I-20121 Milan, Italy. Univ Milano Bicocca, I-20133 Milan, Italy. Agenzia Spaziale Italiana, Sci Data Ctr, I-00198 Rome, Italy. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Penn State Univ, Dept Astron & Astrophys, University Pk, PA 16802 USA. Univ Leicester, Space Res Ctr, Leicester LE1 7RH, Leics, England. Sonoma State Univ, Dept Phys & Astron, Rohnert Pk, CA 94928 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Space Res Assoc, Columbia, MD 21044 USA. Univ Maryland, Joint Ctr Astrophys, Baltimore, MD 21250 USA. CNR, Ist Astrofis Spaziale & Fis Cosm, I-20133 Milan, Italy. CNR, Washington, DC 20418 USA. Univ Southampton, Dept Phys & Astron, Southampton S017 1BJ, Hants, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Natl Radio Astron Observ, Socorro, NM 87801 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Max Planck Inst Extraterr Phys, D-85748 Garching, Germany. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Univ Texas, Dept Astron, Austin, TX 78712 USA. Ctr Etud Saclay, DSM DAPNIA SAP, CEA, F-91191 Gif Sur Yvette, France. Univ Toronto, McClennan Labs, Canadian Inst Theoret Astrophys, Toronto, ON M5S 3H8, Canada. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. L3 Commun EER, Chantilly, VA 20151 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. Osserv Astron Roma, Sede Monteporzio Catone, I-00040 Monte Porzio Catone, Italy. Inst Space & Astronaut Sci, Kanagawa 2298510, Japan. Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 113, Japan. Saitama Univ, Dept Phys, Sakura, Saitama, Japan. Univ Florence, Osservatorio Astron Arcetri, I-50125 Florence, Italy. RP Gehrels, N (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RI White, Nicholas/B-6428-2012; Boyd, Patricia/D-3274-2012; Gehrels, Neil/D-2971-2012; Tueller, Jack/D-5334-2012; Barthelmy, Scott/D-2943-2012; Parsons, Ann/I-6604-2012; Tashiro, Makoto/J-4562-2012 OI White, Nicholas/0000-0003-3853-3462; NR 1 TC 28 Z9 29 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD MAR 1 PY 2005 VL 621 IS 1 BP 558 EP 558 DI 10.1086/427409 PN 1 PG 1 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DR UT WOS:000227406200052 ER PT J AU Nielsen, KE Gull, TR Kober, GV AF Nielsen, KE Gull, TR Kober, GV TI The ultraviolet spectrum of eta Carinae: Investigation of the ejecta absorption SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE circumstellar matter; line : identification; stars : individual (eta Carinae); ultraviolet : stars ID IUE OBSERVATIONS; FERRUM PROJECT; HIGH-VELOCITY; SPECTROSCOPY; HOMUNCULUS; LINES; TRANSITIONS; NEBULA; FEII AB We have investigated the far-through mid-UV ( 1150 - 2360 Angstrom) spectrum of eta Carinae during the late stages of its broad maximum using the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) moderate dispersion echelle modes. The eta Car spectrum is a mixture of absorption and emission lines from the surrounding nebula superimposed on broad stellar wind features. This paper provides a description of the observed spectrum including the wind features, the interstellar absorption, and the emission spectrum from the surrounding nebula, but with the emphasis on the absorption spectrum formed in the foreground ejecta. The ejecta absorption spectrum has a complicated velocity structure in which two velocity structures, at -146 and -513 km s(-1), are easily distinguished. These two velocity components, formed in different regions of the eta Car nebula, have in an earlier analysis been identified and demonstrated to have very different spectral characteristics. The slower velocity component is time variable over the spectroscopic period and is characterized by spectral lines from mainly singly ionized iron-peak elements, while the faster one shows transitions from neutral and singly ionized elements in addition to molecular lines from the hydrogen Lyman bands. The high-velocity H-2 lines dominate great parts of the spectrum with over 800 identified transitions from energy levels up to 30,000 cm(-1). The STIS MAMA data provide the tool for spatial investigations of the central parts of eta Car. H I Lyalpha pumped and semiforbidden emission lines are observed to be formed east of the central source toward Weigelt blobs B and C, located up to 0."2 from the central source. The complete spectrum, with nebular and interstellar line identifications, is available in the electronic edition of the paper. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Catholic Univ Amer, Washington, DC 20064 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. RP Nielsen, KE (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 681, Greenbelt, MD 20771 USA. EM nielsen@stis.gsfc.nasa.gov; theodore.r.gull@nasa.gov; gvieira@stis.gsfc.nasa.gov RI Gull, Theodore/D-2753-2012 OI Gull, Theodore/0000-0002-6851-5380 NR 35 TC 24 Z9 24 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD MAR PY 2005 VL 157 IS 1 BP 138 EP 146 DI 10.1086/427437 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DK UT WOS:000227405500005 ER PT J AU Swartz, WH Yee, JH Shetter, RE Hall, SR Lefer, BL Livingston, JM Russell, PB Browell, EV Avery, MA AF Swartz, WH Yee, JH Shetter, RE Hall, SR Lefer, BL Livingston, JM Russell, PB Browell, EV Avery, MA TI Column ozone and aerosol optical properties retrieved from direct solar irradiance measurements during SOLVE II SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID STELLAR OCCULTATION TECHNIQUE; STRATOSPHERE; WINTER; CAMPAIGN; SYSTEM; OXYGEN; SPACE AB Direct observation of the Sun at large solar zenith angles during the second SAGE III Ozone Loss and Validation Experiment (SOLVE II)/ Validation of International Satellites and study of Ozone Loss (VINTERSOL) campaign by several instruments provided a rich dataset for the retrieval and analysis of line-of-sight column composition, intercomparison, and measurement validation. A flexible, multi-species spectral fitting technique is presented and applied to spectral solar irradiance measurements made by the NCAR Direct beam Irradiance Atmospheric Spectrometer ( DIAS) on-board the NASA DC-8. The approach allows for the independent retrieval of O-3, O-2 . O-2, and aerosol optical properties, by constraining Rayleigh extinction. We examine the 19 January 2003 and 6 February 2003 flights and find very good agreement of O-3 and O-2 . O-2 retrievals with forward-modeling calculations, even at large solar zenith angles, where refraction is important. Intercomparisons of retrieved ozone and aerosol optical thickness with results from the Ames Airborne Tracking Sunphotometer (AATS-14) are summarized. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20707 USA. Natl Ctr Atmospher Res, Boulder, CO 80307 USA. SRI Int, Menlo Pk, CA USA. NASA Ames Res Ctr, Moffett Field, CA USA. NASA, Langley Res Ctr, Hampton, VA 23665 USA. RP Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20707 USA. EM bill.swartz@jhuapl.edu RI Swartz, William/A-1965-2010; Lefer, Barry/B-5417-2012 OI Swartz, William/0000-0002-9172-7189; Lefer, Barry/0000-0001-9520-5495 NR 35 TC 6 Z9 6 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 MAR 1 PY 2005 VL 5 BP 611 EP 622 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 901XT UT WOS:000227316300001 ER PT J AU Eissner, W Landi, E Bhatia, AK AF Eissner, W Landi, E Bhatia, AK TI Atomic data and spectral line intensities for Ar XII SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Article ID NITROGEN ISOELECTRONIC SEQUENCE; RESONANCE LINES; S-X; COLLISION STRENGTHS; DIPOLE TRANSITIONS; RATE COEFFICIENTS; CROSS-SECTIONS; IONIZED ARGON; IONS; ANGSTROM AB Electron impact collision strengths are computed for Ar XII in a distorted wave approach and energy levels, oscillator strengths, spontaneous radiative decay rates for the collision target, as well as collisional high energy limits are obtained from an atomic structure calculation. The target expansion comprises the six spectroscopic configurations 2s(2)p(3), 2s2p(4), 2p(5), 2s(2)2p(2)3s, 2s(2)2p(2)3p, and 2s(2)2p(2)3d, giving rise to 72 fine-structure levels in intermediate coupling. Collision strengths are calculated at five incident energies: 35, 70, 105, 140, and 175 Ry. They are complemented by Coulomb-Born limits towards infinite collision energy for forbidden transitions and line strengths for optically allowed transitions. Excitation rate coefficients are obtained as a function of electron temperature by assuming a Maxwellian electron velocity distribution. 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) at an electron temperature of log T-e/K = 6.4, corresponding to maximum abundance of Ar XII. Relative spectral line intensities are also calculated. 2005 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Inst Theoret Phys, D-70550 Stuttgart, Germany. ARTEP Inc, Columbia, MD 21044 USA. USN, Res Lab, Washington, DC 20375 USA. RP Bhatia, AK (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM bhatia@moksha.gsfc.nasa.gov RI Landi, Enrico/H-4493-2011 NR 29 TC 4 Z9 4 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 MAR PY 2005 VL 89 IS 2 BP 139 EP 194 DI 10.1016/j.adt.2005.02.001 PG 56 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA 925BX UT WOS:000229027600002 ER PT J AU Landi, E Bhatia, AK AF Landi, E Bhatia, AK TI Atomic data and spectral line intensities for NeIII SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Article ID RATE COEFFICIENTS; CROSS-SECTIONS; EMISSION-LINES; EXCITATION; CHIANTI; IONS; NI AB Electron impact collision strengths, energy levels, oscillator strengths, and spontaneous radiative decay rates are calculated for Ne III. The configurations used are 2s(2)2p(4), 2s2p(5), 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, 5.2, 10, 15, 20, and 25 Ry. Excitation rate coefficients are calculated as a function of electron temperature by assuming a Maxwellian electron velocity distribution. 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) to 10(14) cm(-3) at an electron temperature of log T-e (K) = 5.0, corresponding to maximum abundance of Ne III. Relative spectral line intensities are calculated. 2005 Elsevier Inc. All rights C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. ARTEP Inc, Columbia, MD 21044 USA. USN, Res Lab, Washington, DC 20375 USA. RP Bhatia, AK (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM bhatia@moksha.gsfc.nasa.gov RI Landi, Enrico/H-4493-2011 NR 15 TC 8 Z9 8 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 MAR PY 2005 VL 89 IS 2 BP 195 EP 265 DI 10.1016/j.adt.2005.02.003 PG 71 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA 925BX UT WOS:000229027600003 ER PT J AU Flanary, BE Kletetschka, G AF Flanary, BE Kletetschka, G TI Analysis of telomere length and telomerase activity in tree species of various life-spans, and with age in the bristlecone pine Pinus longaeva SO BIOGERONTOLOGY LA English DT Article DE aging; longevity; Pinus aristata; Sequoia sempervirens; senescence ID REPLICATIVE SENESCENCE; HUMAN FIBROBLASTS; IN-VIVO; POLYNUCLEOTIDES; MARGINOTOMY; ASPARAGALES; LONGEVITY; SHORTEN; ORIGIN; CELLS AB Normal somatic cells have a finite replicative capacity. With each cell division, telomeres (the physical ends of linear chromosomes) progressively shorten until they reach a critical length, at which point the cells enter replicative senescence. Some cells maintain telomere length by the action of the telomerase enzyme. The bristlecone pine, Pinus longaeva, is the oldest known living eukaryotic organism, with the oldest on record turning 4770 years old in 2005. To determine what changes occur, if any, in telomere length and telomerase activity with age, and what roles, if any, telomere length and telomerase activity may play in contributing to the increased life-span and longevity of P. longaeva with age, as well as in other tree species of various life-spans, we undertook a detailed investigation of telomere length and telomerase activity in such trees. The results from this study support the hypothesis that both increased telomere length and telomerase activity may directly/indirectly contribute to the increased life-span and longevity evident in long-lived pine trees (2000-5000 year life-spans) compared to medium-lived (400-500 year life-span) and short-lived (100-200 year life-span) pine trees, as well as in P. longaeva with age. C1 Univ Florida, Coll Med, McKnight Brain Inst, Dept Neurosci, Gainesville, FL 32610 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Acad Sci Czech Republ, Inst Geol, Prague, Czech Republic. RP Flanary, BE (reprint author), Univ Florida, Coll Med, McKnight Brain Inst, Dept Neurosci, 100 Newell Dr,L1-100, Gainesville, FL 32610 USA. EM beflana@ufl.edu RI Kletetschka, Gunther/C-9996-2011 OI Kletetschka, Gunther/0000-0002-0645-9037 NR 35 TC 41 Z9 46 U1 2 U2 26 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1389-5729 J9 BIOGERONTOLOGY JI Biogerontology PD MAR PY 2005 VL 6 IS 2 BP 101 EP 111 DI 10.1007/s10522-005-3484-4 PG 11 WC Geriatrics & Gerontology SC Geriatrics & Gerontology GA 948GX UT WOS:000230705200003 PM 16034678 ER PT J AU Polovina, JJ AF Polovina, JJ TI Climate variation, regime shifts, and implications for sustainable fisheries SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT World Conference on the Scientific and Technical Bases for the Sustainability of Fisheries CY NOV 26-30, 2001 CL Univ Miami, Miami, FL HO Univ Miami ID FISH POPULATIONS; PACIFIC SARDINE; VARIABILITY; STRATEGIES AB The term ecosystem regime shift refers to low frequency, high amplitude variation in marine ecosystems involving changes in community composition, species abundances, and trophic structure. Changes occur in the abundance of both exploited and unexploited populations. Temporally coherent changes often occur in other spatially separated ecosystems. Ecosystem regime shifts are thought to be a response to shifts in the ocean and atmosphere climate and hence are relatively coherent with climate changes. However, the mechanisms responsible for ecosystem regime shifts are not well established. Changes in energy flow from the base of the ecosystem is frequently thought to be responsible, but in some cases climate-induced changes in apex predators also result in top-down responses. For example, regime shifts appeared to have occurred in the North Pacific in 1977 and 1989. C1 NOAA, Natl Marine Fisheries Serv, Pacific Isl Fisheries Sci Ctr, Honolulu, HI 96822 USA. RP Polovina, JJ (reprint author), NOAA, Natl Marine Fisheries Serv, Pacific Isl Fisheries Sci Ctr, 2570 Dole St, Honolulu, HI 96822 USA. EM Jeffrey.Polovina@noaa.gov NR 16 TC 53 Z9 56 U1 1 U2 24 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 EI 1553-6955 J9 B MAR SCI JI Bull. Mar. Sci. PD MAR PY 2005 VL 76 IS 2 BP 233 EP 244 PG 12 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 915XY UT WOS:000228346100005 ER PT J AU Chao, WC Chen, B AF Chao, WC Chen, B TI East Asian monsoon misnomer SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. RP Chao, WC (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAR PY 2005 VL 86 IS 3 BP 328 EP + PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 913CQ UT WOS:000228128600013 ER PT J AU Spina, AP AF Spina, AP TI A protective housing for instream data temperature loggers SO CALIFORNIA FISH AND GAME LA English DT Editorial Material ID RIVER; TROUT C1 Natl Marine Fisheries Serv, Long Beach, CA 90802 USA. RP Spina, AP (reprint author), Natl Marine Fisheries Serv, 501 W Ocean Blvd,Suite 4200, Long Beach, CA 90802 USA. EM anthony.spina@noaa.gov NR 5 TC 1 Z9 1 U1 0 U2 0 PU CALIF FISH AND GAME EDITOR PI SACRAMENTO PA 1416 NINTH ST, SACRAMENTO, CA 95814 USA SN 0008-1078 J9 CALIF FISH GAME JI Calif. Fish Game PD SPR PY 2005 VL 91 IS 2 BP 143 EP 147 PG 5 WC Fisheries; Zoology SC Fisheries; Zoology GA 925XE UT WOS:000229086000007 ER PT J AU Kwak, D Kiris, C Kim, CS AF Kwak, D Kiris, C Kim, CS TI Computational challenges of viscous incompressible flows SO COMPUTERS & FLUIDS LA English DT Review ID NAVIER-STOKES EQUATIONS; NUMERICAL-SOLUTION; SCHEMES AB Over the past 30 years, numerical methods and simulation tools for incompressible flows have been advanced as a subset of the computational fluid dynamics (CFD) discipline. Although incompressible flows are encountered in many areas of engineering, simulation of compressible flow has been the major driver for developing computational algorithms and tools. This is probably due to the rather stringent requirements for predicting aerodynamic performance characteristics of flight vehicles, while flow devices involving low-speed or incompressible flow could be reasonably well designed without resorting to accurate numerical simulations. As flow devices are required to be more sophisticated and highly efficient, CFD tools become increasingly important in fluid engineering for incompressible and low-speed flow. This paper reviews some of the successes made possible by advances in computational technologies during the same period, and discusses some of the current challenges faced in computing incompressible flows. (C) 2004 Elsevier Ltd. All rights reserved. C1 NASA, Ames Res Ctr, NAS Div, Applicat Branch, Moffett Field, CA 94035 USA. RP Kwak, D (reprint author), NASA, Ames Res Ctr, NAS Div, Applicat Branch, Mail Stop T27B-1, Moffett Field, CA 94035 USA. EM dkwak@nas.nasa.gov NR 71 TC 26 Z9 26 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-7930 J9 COMPUT FLUIDS JI Comput. Fluids PD MAR PY 2005 VL 34 IS 3 BP 283 EP 299 DI 10.1016/j.compfluid.2004.05.008 PG 17 WC Computer Science, Interdisciplinary Applications; Mechanics SC Computer Science; Mechanics GA 889MH UT WOS:000226446600001 ER PT J AU Dongarra, J Sterling, T Simon, H Strohmaier, E AF Dongarra, J Sterling, T Simon, H Strohmaier, E TI High-performance computing: Clusters, consstellations, MPPs, and future directions SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article C1 Univ Tennessee, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. CALTECH, NASA, Jet Prop Lab, Pasadena, CA 91125 USA. RP Dongarra, J (reprint author), Univ Tennessee, Knoxville, TN 37996 USA. EM dongarra@cs.utk.edu; tron@cacr.caltech.edu; HDSimon@lbl.gov; Estrohmaier@lbl.gov RI Dongarra, Jack/E-3987-2014 NR 5 TC 19 Z9 19 U1 0 U2 3 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD MAR-APR PY 2005 VL 7 IS 2 BP 51 EP 59 DI 10.1109/MCSE.2005.34 PG 9 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 900QE UT WOS:000227228600009 ER PT J AU Gorti, S Forsythe, EL Pusey, ML AF Gorti, S Forsythe, EL Pusey, ML TI Growth modes and energetics of (101) face lysozyme crystal growth SO CRYSTAL GROWTH & DESIGN LA English DT Article ID ATOMIC-FORCE MICROSCOPY; EGG-WHITE LYSOZYME; TETRAGONAL LYSOZYME; CRITICAL-BEHAVIOR; PROTEIN; KINETICS; RATES; TEMPERATURE; PH; CRYSTALLIZATION AB From analyses of lysozyme (101) face growth rate data using a 2D nucleation model for layer-bylayer growth, we find the effective barrier for crystal growth to be gamma = 1.0 +/- 0.2 x 10(-13) erg/molecule. The magnitude of the effective barrier is (2.4 +/- 0.5)k(B)T, at 22 degrees C. We also find that beyond a critical solution supersaturation, sigma(c) crystal growth rates are more accurately described by a kinetic roughening hypothesis. Beyond sigma(c), crystals grow by the continuous addition of molecules anywhere on the crystal surface rather than layer-by-layer. The magnitude of the critical supersaturation (sigma(c) = 1.7 +/- 0.2) for a crossover from a layer-by-layer to continuous growth is found to be statistically independent of the solution conditions that vary with buffer pH, temperature, or precipitant concentration. Using the experimentally determined values for gamma and sigma(c), we find the crystal growth unit to be comprised of 7 +/- 3 molecules. The energy barrier, E-c, for the continuous addition of the growth units is 6.2 +/- 0.3 x 10(-13) erg/molecule or (15 +/- 1)kBT at 22 degrees C. C1 NASA, MSFC, BAE Syst, Phys & Biol Sci Lab, Huntsville, AL 35812 USA. RP Gorti, S (reprint author), NASA, MSFC, BAE Syst, Phys & Biol Sci Lab, Huntsville, AL 35812 USA. EM sridhar.gorti-1@nasa.gov NR 37 TC 12 Z9 12 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1528-7483 J9 CRYST GROWTH DES JI Cryst. Growth Des. PD MAR-APR PY 2005 VL 5 IS 2 BP 473 EP 482 DI 10.1021/cg049733b PG 10 WC Chemistry, Multidisciplinary; Crystallography; Materials Science, Multidisciplinary SC Chemistry; Crystallography; Materials Science GA 903GW UT WOS:000227414900015 ER PT J AU Gorti, S Konnert, J Forsythe, EL Pusey, ML AF Gorti, S Konnert, J Forsythe, EL Pusey, ML TI Effects of kinetic roughening and liquid-liquid phase transition on lysozyme crystal growth velocities SO CRYSTAL GROWTH & DESIGN LA English DT Article ID PROTEIN-WATER SOLUTION; EGG-WHITE LYSOZYME; CRITICAL-BEHAVIOR; GAUSSIAN LIGHT; CORRELATION SPECTROSCOPY; BINARY MIXTURE; SALT-WATER; NUCLEATION; CRYSTALLIZATION; DISTRIBUTIONS AB We measured the growth velocities of the (110) face of tetragonal lysozyme, V (cm/s), at four different concentrations, c (mg/mL), as the solution temperature, T (degrees C or K), was reduced. For a broad range of T dependent on c, we find that the growth velocities increased as the solution temperature was reduced. The initial increase in V is well characterized by the 2D nucleation model for crystal growth, yielding the magnitude of an effective barrier for growth, gamma(s) = (1.2 +/- 0.1) x 10(-13) erg/molecule. Below certain temperatures, T-cr, dependent on c, however, a kinetic roughening hypothesis that considers the continuous addition of molecules anywhere on the crystal surface better describes the observed growth velocities. The application of the continuous growth model, up to the solution cloud-point temperatures, T,1, enabled the determinations of the crossover concentration, c(r), from estimated values of T-cr. all conditions presented, we find that the crossover from growth by 2D nucleation to continuous addition occurs at a supersaturation, sigma(c) = 2.0 +/- 0.1. Moreover, we find the energy barrier for the continuous addition, E, within the temperature range T-cl < T < T-cr to be (6 +/- 1) x 10(-13) erg/molecule. Further reduction of T below similar to 3-4 degrees C of T-cl also revealed a rapid slowing of crystal growth velocities. From quasi-elastic light scattering investigations, we find that the rapid diminishment of crystal growth velocities can be accounted for by the phase behavior of lysozyme solutions. Namely, we find the reversible formation of dense fluid protodroplets comprised of lysozyme molecules to occur below T-cl. Hence, the rapid slowing of growth velocities occurs as a result of the sudden depletion of "mobile" molecules within crystal growth solutions as dense fluid protodroplets form. C1 NASA, BAE Syst, MSFC, Phys & Biol Sci Lab, Huntsville, AL 35812 USA. USN, Res Lab, Struct Matter Lab, Washington, DC 20375 USA. RP Gorti, S (reprint author), NASA, BAE Syst, MSFC, Phys & Biol Sci Lab, Huntsville, AL 35812 USA. EM sridhar.gorti-1@nasa.gov NR 41 TC 10 Z9 10 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1528-7483 J9 CRYST GROWTH DES JI Cryst. Growth Des. PD MAR-APR PY 2005 VL 5 IS 2 BP 535 EP 545 DI 10.1021/cg049696o PG 11 WC Chemistry, Multidisciplinary; Crystallography; Materials Science, Multidisciplinary SC Chemistry; Crystallography; Materials Science GA 903GW UT WOS:000227414900024 ER PT J AU Cuny, J Rhines, PB Kwok, R AF Cuny, J Rhines, PB Kwok, R TI Davis Strait volume, freshwater and heat fluxes SO DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS LA English DT Article DE Davis Strait; Labrador Sea; Baffin Bay; transporter; freshwater; sea ice ID SEA-ICE; NORTH-ATLANTIC; FRAM STRAIT; CANADIAN ARCHIPELAGO; ARCTIC CIRCULATION; OCEAN CIRCULATION; LABRADOR CURRENT; BERING STRAIT; TRANSPORT; CURRENTS AB Volume, freshwater and heat transport through Davis Strait, the northern boundary of the Labrador Basin, are computed using a mooring array deployed for three consecutive years. The net volume, freshwater and heat transports are -2.6 +/- 1.0 Sv, -92 +/- 34 mSv, 18 +/- 17 x 10(12) W. Both southward and northward volume and freshwater transports are maximum in November. The seasonal variability is dictated by the variability in the main water mass transports: Irminger Sea Water, West Greenland shelf water, surface meltwater, and a cold intermediate layer (CIL) originating from Lancaster Sound. The southward freshwater transport seasonal amplitude is dominated by the CIL transport rather than the surface meltwater layer. Sea-ice transport through Davis Strait deduced from remote sensing data is equal to 528 km(3) /year which is much smaller than equivalent estimates for Fram Strait. Using these new estimates, we attempt to close the Arctic Ocean volume and freshwater budget. (c) 2004 Elsevier Ltd. All rights reserved. C1 Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cuny, J (reprint author), Univ Washington, Sch Oceanog, Seattle, WA 98195 USA. EM jcuny@ocean.washington.edu RI Kwok, Ron/A-9762-2008 OI Kwok, Ron/0000-0003-4051-5896 NR 41 TC 80 Z9 81 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0967-0637 J9 DEEP-SEA RES PT I JI Deep-Sea Res. Part I-Oceanogr. Res. Pap. PD MAR PY 2005 VL 52 IS 3 BP 519 EP 542 DI 10.1016/j.dsr.2004.10.006 PG 24 WC Oceanography SC Oceanography GA 911LK UT WOS:000228003800007 ER PT J AU Glazman, RE Weichman, PB AF Glazman, RE Weichman, PB TI Meridional component of oceanic Rossby wave propagation SO DYNAMICS OF ATMOSPHERES AND OCEANS LA English DT Article DE Rossby waves; satellite altimetry ID EXTRATROPICAL PLANETARY-WAVES; BOTTOM TOPOGRAPHY; NORTH PACIFIC; SPEED; ENERGY AB A three-dimensional spectral analysis of Topex altimeter data reveals a large meridional component k(y) of the wavevector k for baroclinic Rossby waves of all timescales. Its existence necessitates some refinements in our estimates of certain basic properties of the Rossby wave field. In particular, by taking into account an actual off-zonal direction of k (often exceeding 70 degrees), one finds that the wavelength, phase speed, and group velocity of mid-latitude Rossby waves (with periods less than 2 years) are much smaller than they appear to be on the assumption of a purely zonal wavenumber vector. Because of a shorter wavelength (yielding U as high as 0.6, where L is the Rossby radius of deformation), these waves are essentially dispersive. Their group velocity vector may depart from zonal by more than 30 degrees. An important intrinsic feature of the wave spectrum confirmed by our analysis is a broadband distribution with respect to k(y). Some of the dynamical implications of the large k(y)/k(x), ratio are discussed. (c) 2004 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Adv Informat Technol, BAE Syst, Burlington, MA 01803 USA. RP Glazman, RE (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM reg@pacific.jpl.nasa.gov NR 31 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0265 J9 DYNAM ATMOS OCEANS JI Dyn. Atmos. Oceans PD MAR PY 2005 VL 38 IS 3-4 BP 173 EP 193 DI 10.1016/j.dynatmoce.2004.11.002 PG 21 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Oceanography GA 930BT UT WOS:000229391500003 ER PT J AU Beard, KH Wang, D Waite, CE Decker, KLM Hawley, GJ DeHayes, DD Hughes, JW Cumming, JR AF Beard, KH Wang, D Waite, CE Decker, KLM Hawley, GJ DeHayes, DD Hughes, JW Cumming, JR TI Quantifying ecosystem controls and their contextual interactions on nutrient export from developing forest mesocosms SO ECOSYSTEMS LA English DT Article DE nutrient export; contextual interactions; leachate; calcium; magnesium; potassium; soil; location; climate; plant community; ecosystem development ID SUCCESSION; AVAILABILITY; PRODUCTIVITY; COMPETITION; HISTORY; CYCLES; FUNGI; STAND; SOIL AB The complexity of natural ecosystems makes it difficult to compare the relative importance of abiotic and biotic factors and to assess the effects of their interactions on ecosystem development. To improve our understanding of ecosystem complexity, we initiated an experiment designed to quantify the main effects and interactions of several factors that are thought to affect nutrient export from developing forest ecosystems. Using a replicated 2 x 2 x 4 factorial experiment, we quantified the main effects of these factors and the factor interactions on annual calcium, magnesium, and potassium export from field mesocosms over 4 years for two Vermont locations, two soils, and four different tree seedling communities. We found that the main effects explained 56%-97% of total variation in nutrient export. Abiotic factors (location and soil) accounted for a greater percentage of the total variation in nutrient export (47%-94%) than the biotic factor (plant community) (2%-15%). However, biotic control over nutrient export was significant, even when biomass was minimal. Factor interactions were often significant, but they explained less of the variation in nutrient export (1%-33%) than the main effects. Year-to-year fluctuations influenced the relative importance of the main effects in determining nutrient export and created factor interactions between most of the explanatory variables. Our study suggests that when research is focused on typically used main effects, such as location and soil, and interactions are aggregated into overall error terms, important information about the factors controlling ecosystem processes can be lost. C1 Univ Vermont, Sch Nat Resources, Aiken Ctr, Burlington, VT 05405 USA. Calif State Univ Monterey Bay, NASA AMES Res Ctr, Moffett Field, CA 94035 USA. W Virginia Univ, Dept Biol, Morgantown, WV 26506 USA. RP Beard, KH (reprint author), Univ Vermont, Sch Nat Resources, Aiken Ctr, Burlington, VT 05405 USA. EM kbeard@cc.usu.edu RI Beard, Karen/B-7177-2011; Decker, Kelly/J-1831-2012 NR 43 TC 0 Z9 0 U1 0 U2 2 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1432-9840 J9 ECOSYSTEMS JI Ecosystems PD MAR PY 2005 VL 8 IS 2 BP 210 EP 224 DI 10.1007/s10021-004-0041-y PG 15 WC Ecology SC Environmental Sciences & Ecology GA 932FR UT WOS:000229540100009 ER PT J AU Quinn, J Geiger, C Clausen, C Brooks, K Coon, C O'Hara, S Krug, T Major, D Yoon, WS Gavaskar, A Holdsworth, T AF Quinn, J Geiger, C Clausen, C Brooks, K Coon, C O'Hara, S Krug, T Major, D Yoon, WS Gavaskar, A Holdsworth, T TI Field demonstration of DNAPL dehalogenation using emulsified zero-valent iron SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article AB This paper describes the results of the first field-scale demonstration conducted to evaluate the performance of nanoscale emulsified zero-valent iron (EZVI) injected into the saturated zone to enhance in situ dehalogenation of dense, nonaqueous phase liquids (DNAPLs) containing trichloroethene (TCE). EZVI is an innovative and emerging remediation technology. EZVI is a surfactant-stabilized, biodegradable emulsion that forms emulsion droplets consisting of an oil-liquid membrane surrounding zerovalent iron (ZVI) particles in water. EZVI was injected over a five day period into eight wells in a demonstration test area within a larger DNAPL source area at NASA's Launch Complex 34 (LC34) using a pressure pulse injection method. Soil and groundwater samples were collected before and after treatment and analyzed for volatile organic compounds (VOCs) to evaluate the changes in VOC mass, concentration and mass flux. Significant reductions in TCE soil concentrations (>80%) were observed at four of the six soil sampling locations within 90 days of EZVI injection. Somewhat lower reductions were observed at the other two soil sampling locations where visual observations suggest that most of the EZV1 migrated up above the target treatment depth. Significant reductions in TICE groundwater concentrations (57 to 100%) were observed at all depths targeted with EZVI. Groundwater samples from the treatment area also showed significant increases in the concentrations of cis-1,2-dichloroethene (cDCE), vinyl chloride (VC) and ethene. The decrease in concentrations of TICE in soil and groundwater samples following treatment with EZVI is believed to be due to abiotic degradation associated with the ZVI as well as biodegradation enhanced by the presence of the oil and surfactant in the EZVI emulsion, C1 NASA, Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. Univ Cent Florida, Orlando, FL 32816 USA. GeoSyntec Consultants Inc, Guelph, ON N1G 5G3, Canada. Battelle Mem Inst, Columbus, OH 43201 USA. US EPA, Cincinnati, OH 45268 USA. RP Quinn, J (reprint author), NASA, Kennedy Space Ctr, Mail Stop YA-C3-C, Kennedy Space Ctr, FL 32899 USA. EM Jacqueline.W.Quinn@nasa.gov; tkrug@geosyntec.com NR 20 TC 204 Z9 220 U1 15 U2 117 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAR 1 PY 2005 VL 39 IS 5 BP 1309 EP 1318 DI 10.1021/es0490018 PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 901BG UT WOS:000227257400025 PM 15787371 ER PT J AU Florescu, M Scheel, S Haffner, HH Lee, H Strekalov, D Knight, PL Dowling, JP AF Florescu, M Scheel, S Haffner, HH Lee, H Strekalov, D Knight, PL Dowling, JP TI Single photons on demand from 3D photonic band-gap structures SO EUROPHYSICS LETTERS LA English DT Article ID QUANTUM CRYPTOGRAPHY; SPONTANEOUS EMISSION; TURNSTILE DEVICE; STATES; CAVITY; DOT; ER AB We describe a practical implementation of a (semi-deterministic) photon gun based on stimulated Raman adiabatic passage pumping and the strong enhancement of the photonic density of states in a photonic band-gap material. We show that this device allows deterministic and unidirectional production of single photons with a high repetition rate of the order of 100 kHz. We also discuss specific 3D photonic micro-structure architectures in which our model can be realized and the feasibility of implementing such a device using Er3+ ions that produce single photons at the telecommunication wavelength of 1.55 mu m. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, QOLS, London SW7 2BW, England. Univ Innsbruck, Inst Phys Expt, A-6020 Innsbruck, Austria. Louisiana State Univ, Dept Phys & Astron, Hearne Inst Theoret Phys, Baton Rouge, LA 70803 USA. RP Florescu, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Marian.Florescu@jpl.nasa.gov RI Florescu, Marian/E-9009-2010; Haeffner, Hartmut/D-8046-2012; DOWLING, JONATHAN/L-2749-2013 OI Haeffner, Hartmut/0000-0002-5113-9622; NR 37 TC 12 Z9 12 U1 0 U2 4 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD MAR PY 2005 VL 69 IS 6 BP 945 EP 951 DI 10.1209/epl/i2004-10453-5 PG 7 WC Physics, Multidisciplinary SC Physics GA 917GX UT WOS:000228445900014 ER PT J AU Penix, J Visser, W Park, S Pasareanu, C Engstrom, E Larson, A Weininger, N AF Penix, J Visser, W Park, S Pasareanu, C Engstrom, E Larson, A Weininger, N TI Verifying time partitioning in the DEOS scheduling kernel SO FORMAL METHODS IN SYSTEM DESIGN LA English DT Article DE program model checking; spin; time partitioning; verification; predicate abstraction ID MODEL-CHECKING; SPECIFICATIONS; VERIFICATION; SOFTWARE; REQUIREMENTS AB This paper describes an experiment to use the Spin model checking system to support automated verification of time partitioning in the Honeywell DEOS real-time scheduling kernel. The goal of the experiment was to investigate whether model checking with minimal abstraction could be used to find a subtle implementation error that was originally discovered and fixed during the standard formal review process. The experiment involved translating a core slice of the DEOS scheduling kernel from C++ into Promela, constructing an abstract "test-driver" environment and carefully introducing several abstractions into the system to support verification. Attempted verification of several properties related to time-partitioning led to the rediscovery of the known error in the implementation. The case study indicated several limitations in existing tools to support model checking of software. The most difficult task in the original DEOS experiment was constructing an adequate environment to close the system for verification. The fidelity of the environment was of crucial importance for achieving meaningful results during model checking. In this paper, we describe the initial environment modeling effort and a follow-on experiment with using semi-automated environment generation methods. Program abstraction techniques were also critical for enabling verification of DEOS. We describe an implementation scheme for predicate abstraction, an approach based on abstract interpretation, which was developed to support DEOS verification. C1 NASA, Ames Res Ctr, Intelligent Syst Div, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Adv Comp Sci Res Inst, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, Kestrel Technol, Moffett Field, CA 94035 USA. Honeywell Technol Ctr, Minneapolis, MN 55418 USA. RP NASA, Ames Res Ctr, Intelligent Syst Div, Moffett Field, CA 94035 USA. EM john.penix@nasa.gov; wvisser@email.arc.nasa.gov; pcorina@email.arc.nasa.gov; eric.engstrom@honeywell.com NR 68 TC 9 Z9 9 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0925-9856 EI 1572-8102 J9 FORM METHOD SYST DES JI Form. Methods Syst. Des. PD MAR PY 2005 VL 26 IS 2 BP 103 EP 135 DI 10.1007/s10703-005-1490-4 PG 33 WC Computer Science, Theory & Methods SC Computer Science GA 959EY UT WOS:000231501500003 ER PT J AU Vintzileos, A Rienecker, MM Suarez, MJ Schubert, SD Miller, SK AF Vintzileos, A Rienecker, MM Suarez, MJ Schubert, SD Miller, SK TI Local versus remote wind forcing of the equatorial Pacific surface temperature in July 2003 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID 1997-98 EL-NINO; JULIAN OSCILLATION; TROPICAL PACIFIC; MODEL; OCEAN; TERMINATION; EVOLUTION; MADDEN; ENSO AB [1] After the moderate El Nino of 2002 the tropical Pacific seemed poised to enter a La Nino phase. Wind anomalies during May and June 2003, however, led to a sudden termination of this event. Counter to earlier predictions, forecasts from July 2003 correctly predicted normal conditions for the remainder of the year. In this paper the causes of this abrupt turn of events are analyzed. It is shown that wind anomalies in the eastern tropical Pacific played a major role in terminating the incipient cold ENSO phase. Although westerly wind bursts in the western Pacific explained most of the ocean subsurface behavior to the west of 110 degrees W, their impact on SST was confined to the central equatorial Pacific. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. NOAA, NCEP, EMC, UCAR, Camp Springs, MD 20746 USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. RP Vintzileos, A (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. EM augustin.vintzileos@noaa.gov NR 21 TC 8 Z9 8 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 MAR 1 PY 2005 VL 32 IS 5 AR L05702 DI 10.1029/2004GL02197 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 905DL UT WOS:000227547800005 ER PT J AU Verbanac, G de Pater, I Showalter, MR Lissauer, JJ AF Verbanac, G de Pater, I Showalter, MR Lissauer, JJ TI Keck infrared observations of Saturn's main rings bracketing Earth's August 1995 ring plane crossing SO ICARUS LA English DT Article DE planetary rings, Saturn; photometry ID F-RING; BRIGHTNESS; PHOTOMETRY; GALAXY; SYSTEM AB We present results of near-infrared (2.26 mu m) observations of Saturn's main rings taken with the W.M. Keck telescope during August 8-11, 1995, surrounding the time that Earth crossed Saturn's ring plane. These observations provide a unique opportunity to study the evolution of the ring brightness in detail, and by combining our data with Hubble Space Telescope (HST) results (Nicholson et al., 1996, Science 272, 453-616), we extend the 12-hour HST time span to several days around the time of ring plane crossing (RPX). In this paper, we focus on the temporal evolution of the brightness in Saturn's main rings. We examine both edge-on ring profiles and radial profiles obtained by "onion-peeling" the edge-on data. Before RPX, when the dark (unlit) face of the rings was observed, the inner C ring (including the Colombo gap), the Maxwell gap, Cassini Division and F ring region were very bright in transmitted light. After RPX, the main rings brighten rapidly, as expected. The profiles show east-west asymmetries both before and after RPX. Prior to RPX, the evolution in ring brightness of the Keck and HST data match one another quite well. The west side of the rings showed a nonlinear variation in brightness during the last hours before ring plane crossing, suggestive of clumping and longitudinal asymmetries in the F ring. Immediately after RPX, the east side of the rings brightened more rapidly than the west. A quantitative comparison of the Keck and HST data reveals that the rings were redder before RPX than after; we ascribe this difference to the enhanced multiple scattering of photons passing through to the unlit side of the rings. (c) 2004 Elsevier Inc. All rights reserved. C1 Geophys Inst Andrija Mohorov, Horvatovac BB, Zagreb 1000, Croatia. Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Stanford Univ, Ctr Radar Astron, Stanford, CA 94305 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Verbanac, G (reprint author), Geophys Inst Andrija Mohorov, Horvatovac BB, Zagreb 1000, Croatia. EM verbanac@irb.hr NR 22 TC 2 Z9 2 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 MAR PY 2005 VL 174 IS 1 BP 241 EP 252 DI 10.1016/j.icarus.2004.10.008 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 913FL UT WOS:000228136900017 ER PT J AU Xiong, FQ Romanofsky, RR AF Xiong, FQ Romanofsky, RR TI Study of behavior of digital modulations for beam steerable reflectarray antennas SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE digital modulation; reflectarray antenna ID PHASE SHIFTERS AB This paper investigates the bit error rate (BER) performance of digital modulations in a system with a scanning reflectarray antenna. A reflectarray causes intersymbol interference (ISI) in a digitally modulated signal, its phase shifters' phase errors cause signal distortion, and its phase shifters' phase transient causes beam pattern degradation during direction switching. In this paper, composite signal models of the reflectarray are established for both static and transient states. Due to different feed-to-element distances and the element-to-observation distances, different delays exist in signal components. These delays cause ISI whose effect is analyzed and evaluated. Effects of phase shifters' phase errors and phase transient during beam switching are also analyzed and evaluated. Numerical calculations and simulations are performed. The analytical and simulation results for an example reflectarray at f(c) = 26.5 GHz and bit rate of 1.325 Gbps show that the BER degradation due to ISI is proportional to the symbol rate and the loss ranges from about 1 dB to around 2 dB in E-b/N-o, depending on original E-b/N-o, for BPSK, QPSK, 8PSK, and 16QAM. The phase error effect is negligible for lower order modulations and is unacceptable for higher order modulations such as 64QAM and 256QAM. The degradation due to phase transient effect is about 2 dB for BPSK and QPSK. C1 Cleveland State Univ, Dept Elect & Comp Engn, Cleveland, OH 44116 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Xiong, FQ (reprint author), Cleveland State Univ, Dept Elect & Comp Engn, Cleveland, OH 44116 USA. EM f.xiong@csuohio.edu; Robert.R.Romanofsky@grc.nasa.gov NR 10 TC 7 Z9 7 U1 0 U2 1 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 MAR PY 2005 VL 53 IS 3 BP 1083 EP 1097 DI 10.1109/TAP.2004.842694 PG 15 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 904OZ UT WOS:000227508900023 ER PT J AU Heymann, M Lin, F Meyer, G Resmerita, S AF Heymann, M Lin, F Meyer, G Resmerita, S TI Analysis of Zeno behaviors in a class of hybrid systems SO IEEE TRANSACTIONS ON AUTOMATIC CONTROL LA English DT Article DE control; hybrid systems; Zenoness ID CONTROLLERS; AUTOMATA AB This note investigates conditions for existence of Zeno behaviors (where a system undergoes an unbounded number of discrete transitions in a finite length of time) in a class of hybrid systems. Zeno behavior occurs, for example, when a controller unsuccessfully attempts to satisfy an invariance specification by switching the system among different configurations faster and faster. Two types of Zeno systems are investigated: (1) strongly Zeno systems where all runs of the system are Zeno and (2) (weakly) Zeno systems where only some runs of the system are Zeno. For constant-rate and bounded-rate hybrid systems and some nonlinear generalizations, necessary and sufficient conditions for both Zenoness and strong Zenoness are derived. The analysis is based on studying the trajectory set of a certain "equivalent" continuous-time system that is associated with the dynamic equations of the hybrid system. The relation between the possibility of existence of Zeno behaviors in a system and the problem of existence of non-Zeno safety controllers (that keep the system in a specified region of its operating space) is also examined. It is shown that in certain Zeno systems, a minimally-interventive safety controller may not exist, even if a safety controller exists, disproving a conjecture made earlier in the literature. C1 Technion Israel Inst Technol, Dept Comp Sci, IL-32000 Haifa, Israel. Wayne State Univ, Dept Elect & Comp Engn, Detroit, MI 48202 USA. Tongji Univ, Sch Elect & Informat Engn, Shanghai 200092, Peoples R China. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Heymann, M (reprint author), Technion Israel Inst Technol, Dept Comp Sci, IL-32000 Haifa, Israel. EM heymann@cs.technion.ac.il; flin@ece.eng.wayne.edu; George.Meyer-1@nasa.gov; stefan@cs.technion.ac.il NR 16 TC 36 Z9 37 U1 0 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9286 J9 IEEE T AUTOMAT CONTR JI IEEE Trans. Autom. Control PD MAR PY 2005 VL 50 IS 3 BP 376 EP 383 DI 10.1109/TAC.2005.843874 PG 8 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA 907WB UT WOS:000227747700009 ER PT J AU Kukreja, SL Kearney, RE Galiana, HL AF Kukreja, SL Kearney, RE Galiana, HL TI A least-squares parameter estimation algorithm for switched Hammerstein systems with applications to the VOR SO IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING LA English DT Article DE Hammerstein systems; least-squares; mathematical modeling; NARMAX; parametric models; switched systems; system identification ID NON-LINEAR SYSTEMS; PIECEWISE AFFINE SYSTEMS; VESTIBULOOCULAR REFLEX; VESTIBULAR-NYSTAGMUS; IDENTIFICATION; MODELS; REPRESENTATIONS; CLASSIFICATION; GENERATION; BEHAVIOR AB A "multimode" or "switched" system is one that switches between various modes of operation. When a switch occurs from one mode to another, a discontinuity may result followed by a smooth evolution under the new regime. Characterizing the switching behavior of these systems is not well understood and, therefore, identification of multimode systems typically requires a preprocessing step to classify the observed data according to a mode of operation. A further consequence of the switched nature of these systems is that data available for parameter estimation of any subsystem may be inadequate. As such, identification and parameter estimation of multimode systems remains an unresolved problem. In this paper, we 1) show that the NARMAX model structure can be used to describe the impulsive-smooth behavior of switched systems, 2) propose a modified extended least squares (MELS) algorithm to estimate the coefficients of such models, and 3) demonstrate its applicability to simulated and real data from the Vestibulo-Ocular Reflex (VOR). The approach will also allow the identification of other nonlinear bio-systems, suspected of containing "hard" nonlinearities. C1 McGill Univ, Dept Biomed Engn, Montreal, PQ H3A 2B4, Canada. NASA, Dryden Flight Res Ctr, Edwards AFB, CA 93523 USA. RP McGill Univ, Dept Biomed Engn, Montreal, PQ H3A 2B4, Canada. EM sunil.kukreja@nasa.gov; robert.kearney@mcgill.ca; henrietta.galiana@mcgill.ca NR 48 TC 22 Z9 23 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-9294 EI 1558-2531 J9 IEEE T BIO-MED ENG JI IEEE Trans. Biomed. Eng. PD MAR PY 2005 VL 52 IS 3 BP 431 EP 444 DI 10.1109/TBME.2004.843286 PG 14 WC Engineering, Biomedical SC Engineering GA 899JA UT WOS:000227139500010 PM 15759573 ER PT J AU Chen, YC M'Closkey, RT Tran, TA Blaes, B AF Chen, YC M'Closkey, RT Tran, TA Blaes, B TI A control and signal processing integrated circuit for the JPL-Boeing micromachined gyroscopes SO IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY LA English DT Article DE application specific integrated circuits; gain control; gyroscopes; microelectromechanical devices ID VIBRATORY GYROSCOPE; MICROSPACECRAFT AB A special-purpose integrated circuit that accomplishes the real-time control and filtering tasks for the JPL-Boeing micromachined gyroscopes using a flexible, low-power implementation is presented. Our exposition focuses on the integration of the circuit and a prototype sensor, the synthesis and implementation of the control filters, and the subsequent performance of the closed-loop system. Identified sensor models are also presented because the control approach and, hence, the circuit architecture, is motivated by special features of the sensor dynamics. C1 Univ Calif Los Angeles, Dept Aerosp & Mech Engn, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chen, YC (reprint author), Univ Calif Los Angeles, Dept Aerosp & Mech Engn, Los Angeles, CA 90095 USA. EM rtm@obsidian.seas.ucla.edu NR 16 TC 39 Z9 49 U1 1 U2 7 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1063-6536 J9 IEEE T CONTR SYST T JI IEEE Trans. Control Syst. Technol. PD MAR PY 2005 VL 13 IS 2 BP 286 EP 300 DI 10.1109/TCST.2004.839558 PG 15 WC Automation & Control Systems; Engineering, Electrical & Electronic SC Automation & Control Systems; Engineering GA 901EC UT WOS:000227264800011 ER PT J AU Richards, JA Crawford, MM Kerkes, JP Serpico, SB Tilton, JC AF Richards, JA Crawford, MM Kerkes, JP Serpico, SB Tilton, JC TI Foreword to the special issue on advances in techniques for analysis of remotely sensed data SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Editorial Material C1 Australian Natl Univ, Res Sch Informat Sci & Engn, Canberra, ACT 0200, Australia. Univ Texas, Ctr Space Res, Austin, TX 78712 USA. MIT Lincoln Lab, Sensor Technol & Syst Applicat Grp, Lexington, MA 02420 USA. Univ Genoa, Dept Biophys & Elect Engn, I-16145 Genoa, Italy. NASA, Goddard Space Flight Ctr, Appl Informat Sci Branch, Greenbelt, MD 20771 USA. RP Richards, JA (reprint author), Australian Natl Univ, Res Sch Informat Sci & Engn, GPO Box 4, Canberra, ACT 0200, Australia. NR 0 TC 2 Z9 2 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD MAR PY 2005 VL 43 IS 3 BP 411 EP 413 DI 10.1109/TGRS.2005.843752 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 899FJ UT WOS:000227130000001 ER PT J AU Aksoy, S Koperski, K Tusk, C Marchisio, G Tilton, JC AF Aksoy, S Koperski, K Tusk, C Marchisio, G Tilton, JC TI Learning Bayesian classifiers for scene classification with a visual grammar SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT IEEE Workshop on Advances in Techniques for Analysis of Remotely Sensed Data held in Honor of David A Landgrebe CY OCT 27-28, 2003 CL NASA Goddard Space Flight Visitor Ctr, Greenbelt, MD SP IEEE HO NASA Goddard Space Flight Visitor Ctr DE data fusion; image classification; image segmentation; spatial relationships; visual grammar ID RETRIEVAL; FEATURES AB A challenging problem in image content extraction and classification is building a system that automatically learns high-level semantic interpretations of images. We describe a Bayesian framework for a visual grammar that aims to reduce the gap between low-level features and high-level user semantics. Our approach includes modeling image pixels using automatic fusion of their spectral, textural, and other ancillary attributes; segmentation of image regions using an iterative split-and-merge algorithm; and representing scenes by decomposing them into prototype regions and modeling the interactions between these regions in terms of their spatial relationships. Naive Bayes classifiers are used in the learning of models for region segmentation an classification using positive and negative examples for user-defined semantic land cover labels. The system also automatically learns representative region groups that can distinguish different scenes and builds visual grammar models. Experiments using Landsat scenes show that the visual grammar enables creation of high-level classes that cannot be modeled by individual pixels or regions. Furthermore, learning of the classifiers requires only a few training examples. C1 Bilkent Univ, Dept Comp Engn, TR-06800 Ankara, Turkey. Insightful Corp, Seattle, WA 98109 USA. NASA Goddard Space Flight Ctr, Greenbelt, MD USA. RP Aksoy, S (reprint author), Bilkent Univ, Dept Comp Engn, TR-06800 Ankara, Turkey. EM saksoy@cs.bilkent.edu.tr; krisk@insightful.com; ctusk@insightful.com; giovanni@insightful.com; James.C.Tilton@nasa.gov RI Aksoy, Selim/C-3365-2008 OI Aksoy, Selim/0000-0003-4185-0565 NR 21 TC 76 Z9 85 U1 2 U2 11 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 MAR PY 2005 VL 43 IS 3 BP 581 EP 589 DI 10.1109/TGRS.2004.839547 PG 9 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 899FJ UT WOS:000227130000017 ER PT J AU Srivastava, AN Oza, NC Stroeve, J AF Srivastava, AN Oza, NC Stroeve, J TI Virtual sensors: Using data mining techniques to efficiently estimate remote sensing spectra SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article; Proceedings Paper CT IEEE Workshop on Advances in Techniques for Analysis of Remotely Sensed Data held in Honor of David A Landgrebe CY OCT 27-28, 2003 CL NASA Goddard Space Flight Visitor Ctr, Greenbelt, MD SP IEEE HO NASA Goddard Space Flight Visitor Ctr DE Advanced Very High Resolution Radiometer (AVHRR); cloud detection; data mining; kernel methods; Moderate Resolution Imaging Spectrometer (MODIS); neural networks; remote sensing; support vector machine (SVM) AB Various instruments are used to create images of the earth and other objects in the universe in a diverse set of wavelength bands with the aim of understanding natural phenomena. Sometimes these instruments are built in a phased approach, with additional measurement capabilities added in later phases. In other cases, technology may mature to the point that the instrument offers new measurement capabilities that were not planned in the original design of the instrument. In still other cases, high-resolution spectral measurements may be too costly to perform on a large sample, and therefore, lower resolution spectral instruments are used to take the majority of measurements. Many applied science questions that are relevant to the earth science remote sensing community require analysis of enormous amounts of data that were generated by instruments with disparate measurement capabilities. This paper addresses this problem using virtual sensors: a method that uses models trained on spectrally rich (high spectral resolution) data to "fill in" unmeasured spectral channels in spectrally poor (low spectral resolution) data. The models we use in this paper are multilayer perceptrons, support vector machines (SVMs) with radial basis function kernels, and SVMs with mixture density Mercer kernels. We demonstrate this method by using models trained on the high spectral resolution Terra Moderate Resolution Imaging Spectrometer (MODIS) instrument to estimate what the equivalent of the MODIS 1.6-mum channel would be for the National Oceanic and Atmospheric Administration Advanced Very High Resolution Radiometer (AVHRR/2) instrument. The scientific motivation for the simulation of the 1.6-mum channel is to improve the ability of the AVHRR/2 sensor to detect clouds over snow and ice. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Colorado, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA. RP Srivastava, AN (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM ashok@email.arc.nasa.gov RI Stroeve, Julienne/D-1525-2010 NR 7 TC 12 Z9 13 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 MAR PY 2005 VL 43 IS 3 BP 590 EP 600 DI 10.1109/TGRS.2004.842406 PG 11 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 899FJ UT WOS:000227130000018 ER PT J AU Sethares, WA Morris, RD Sethares, JC AF Sethares, WA Morris, RD Sethares, JC TI Beat tracking of musical performances using low-level audio features SO IEEE TRANSACTIONS ON SPEECH AND AUDIO PROCESSING LA English DT Article DE musical rhythm; particle filters; rhythmic analysis; spectral center; spectral dispersion; tempo tracking ID PERCEPTION; RHYTHM; CLASSIFICATION; SIGNALS; TEMPO AB This paper presents and compares two methods of tracking the beat in musical performances, one based on a Bayesian decision framework and the other a gradient strategy. The techniques can be applied directly to a digitized performance (i.e., a soundfile) and do not require a musical score or a MIDI transcription. In both cases, the raw audio is first processed into a collection of "rhythm tracks" which represent the time evolution of various low-level features. The Bayesian approach chooses a set of parameters that represent the beat by modeling the rhythm tracks as a concatenation of random variables with a patterned structure of variances. The output of the estimator is a trio of parameters that represent the interval between beats, its change (derivative), and the position of the starting beat. Recursive (and potentially real time) approximations to the method are derived using particle filters, and their behavior is investigated via simulation on a variety of musical sources. The simpler method, which performs a gradient descent over a window of beats, tends to converge more slowly and to undulate about the desired answer. Several examples are presented that highlight both the strengths and weaknesses of the approaches. C1 Univ Wisconsin, Dept Elect & Comp Engn, Madison, WI 53706 USA. NASA, Ames Res Ctr, RIACS, Moffett Field, CA 94035 USA. RP Sethares, WA (reprint author), Univ Wisconsin, Dept Elect & Comp Engn, 1415 Johnson Dr, Madison, WI 53706 USA. NR 36 TC 21 Z9 21 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1063-6676 J9 IEEE T SPEECH AUDI P JI IEEE Trans. Speech Audio Process. PD MAR PY 2005 VL 13 IS 2 BP 275 EP 285 DI 10.1109/TSA.2004.841053 PG 11 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA 899UP UT WOS:000227171300013 ER PT J AU Chu, T Mahajan, A DiGregorio, A Russell, SS AF Chu, T Mahajan, A DiGregorio, A Russell, SS TI Determination of optimal experimental parameters for transient thermography imaging using finite-element models SO IMAGING SCIENCE JOURNAL LA English DT Article DE NDE; FEA; thermography; composite materials; optimal inspection ID COMPOSITES AB A study was conducted to determine the optimal inspection parameters such as range and time for finding defects in carbon/epoxy composite panels using IR thermography imaging. The present paper presents an innovative method for automatically selecting these parameters for evaluating composites based on a series of finite-element models. Such finite-element models of composite panels with flaws at different depth locations were constructed a priori and analysed to estimate the optimal operating parameters. The optimal inspection range and time were identified in the contour plots obtained from the appropriate finite-element analysis results. A graphite-epoxy composite panel with phantom defects at various depth locations was built, and experiments were performed using a thermographic system to verify and validate the proposed method. C1 So Illinois Univ, Dept Mech Engn & Energy Proc, Carbondale, IL 62901 USA. NASA, George C Marshall Space Flight Ctr, Mat Proc & Mfg Dept, ED32 Mat & Proc Lab, Huntsville, AL 35812 USA. RP Mahajan, A (reprint author), So Illinois Univ, Dept Mech Engn & Energy Proc, Carbondale, IL 62901 USA. EM mahajan@engr.siu.edu RI Chu, Tsuchin/F-3445-2013 OI Chu, Tsuchin/0000-0002-6939-9924 NR 10 TC 7 Z9 7 U1 0 U2 3 PU MANEY PUBLISHING PI LEEDS PA HUDSON RD, LEEDS LS9 7DL, ENGLAND SN 1368-2199 J9 IMAGING SCI J JI Imaging Sci. J. PD MAR PY 2005 VL 53 IS 1 BP 20 EP 26 DI 10.1179/136821904X13011 PG 7 WC Imaging Science & Photographic Technology SC Imaging Science & Photographic Technology GA 919HA UT WOS:000228607800003 ER PT J AU Gonda, SR Culbertson, CT Behravesh, E Huff, JL Pollanen, R Wu, H Pellis, NR Ramsey, JM AF Gonda, S. R. Culbertson, C. T. Behravesh, E. Huff, J. L. Pollanen, R. Wu, H. Pellis, N. R. Ramsey, J. M. TI Cell-based models and technologies for space environment monitoring SO IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY-ANIMAL LA English DT Meeting Abstract C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Kansas State Univ, Dept Chem, Manhattan, KS 66506 USA. USRA, Dept Space Life Sci, Houston, TX 77058 USA. Univ N Carolina, Dept Chem Campus, Chapel Hill, NC 27599 USA. RI Pollanen, Raimo/A-5999-2009 NR 0 TC 0 Z9 0 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1071-2690 J9 IN VITRO CELL DEV-AN JI In Vitro Cell. Dev. Biol.-Anim. PD SPR PY 2005 VL 41 BP 8A EP 8A PG 1 WC Cell Biology; Developmental Biology SC Cell Biology; Developmental Biology GA V44IC UT WOS:000202995400027 ER PT J AU Ward, NE Pellis, NR Risin, S Risin, D AF Ward, N. E. Pellis, N. R. Risin, S. Risin, D. TI Gene expression alterations in activated human T-cells induced by modeled Microgravity SO IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY-ANIMAL LA English DT Meeting Abstract C1 Wyle Life Sci, Houston, TX USA. Univ Texas Houston, Sch Med, Houston, TX USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. EM nward@ems.jsc.nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1071-2690 J9 IN VITRO CELL DEV-AN JI In Vitro Cell. Dev. Biol.-Anim. PD SPR PY 2005 VL 41 BP 8A EP 8A PG 1 WC Cell Biology; Developmental Biology SC Cell Biology; Developmental Biology GA V44IC UT WOS:000202995400030 ER PT J AU Khaoustov, VI Risin, D Pellis, NR Yoffe, B AF Khaoustov, V. I. Risin, D. Pellis, N. R. Yoffe, B. TI Liver tissue engineering in Microgravity environment SO IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY-ANIMAL LA English DT Meeting Abstract C1 Baylor Coll Med, Houston, TX 77030 USA. NASA, Biotechnol Program, Houston, TX 77058 USA. EM adimirk@bcm.tmc.edu NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 1071-2690 J9 IN VITRO CELL DEV-AN JI In Vitro Cell. Dev. Biol.-Anim. PD SPR PY 2005 VL 41 BP 61A EP 61A PG 1 WC Cell Biology; Developmental Biology SC Cell Biology; Developmental Biology GA V44IC UT WOS:000202995400228 ER PT J AU Wise, KC Manna, SK Yamauchi, K Ramesh, V Wilson, BL Thomas, RL Sarkar, S Kulkarni, AD Pellis, NR Ramesh, GT AF Wise, KC Manna, SK Yamauchi, K Ramesh, V Wilson, BL Thomas, RL Sarkar, S Kulkarni, AD Pellis, NR Ramesh, GT TI Activation of nuclear transcription factor-kappa B in mouse brain induced by a simulated microgravity environment SO IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY-ANIMAL LA English DT Article DE simulated microgravity; hindlimb unloading; reactive oxygen species of NF-kappa B; MAPKK; glutathione ID OXIDATIVE STRESS; PROTEIN-KINASES; IMMUNE-SYSTEM; HUMAN-DISEASE; GLUTATHIONE; APOPTOSIS; SPACEFLIGHT; MODEL; SURVIVAL; PATHWAY AB Microgravity induces inflammatory responses and modulates immune functions that may increase oxidative stress. Exposure to a microgravity environment induces adverse neurological effects, however, there is little research exploring the etiology of these effects resulting front exposure to such an environment. It is also known that spaceflight is associated with increase in oxidative stress, however, this phenomenon has not been reproduced in land-based simulated microgravity models. In this study, an attempt has been made to show the induction of reactive oxygen species (ROS) in mice brain, using ground-based microgravity simulator. Increased ROS was observed in brain stem and frontal cortex with concomitant decrease in glutathione, on exposing mice to simulated microgravity for 7 d. Oxidative stress-induced activation of nuclear factor-kappaB was observed in all the regions of the brain. Moreover, mitogen-activated protein kinase kinase was phosphorylated equally in all regions of the brain exposed to simulated microgravity. These results suggest that exposure of brain to simulated microgravity v can induce expression of certain transcription factors, and these have been earlier argued to be oxidative stress dependent. C1 Texas So Univ, Dept Biol, Mol Neurotoxicol Lab, Houston, TX 77004 USA. Univ Texas, Dept Surg, Houston, TX 77030 USA. Ctr DNA Fingerprinting & Diagnost, Immunol Lab, Hyderabad 500076, Andhra Pradesh, India. NASA, Lyndon B Johnson Space Ctr, Cellular Biotechnol Program, Houston, TX 77058 USA. RP Ramesh, GT (reprint author), Texas So Univ, Dept Biol, Mol Neurotoxicol Lab, Houston, TX 77004 USA. EM ramesh_gt@tsu.edu NR 46 TC 24 Z9 27 U1 0 U2 0 PU SOC IN VITRO BIOLOGY PI LARGO PA 9315 LARGO DR WEST, STE 25, LARGO, MD 20774 USA SN 1071-2690 J9 IN VITRO CELL DEV-AN JI In Vitro Cell. Dev. Biol.-Anim. PD MAR-APR PY 2005 VL 41 IS 3-4 BP 118 EP 123 PG 6 WC Cell Biology; Developmental Biology SC Cell Biology; Developmental Biology GA 946KM UT WOS:000230571000010 PM 16029073 ER PT J AU Dellnitz, M Junge, O Koon, WS Lekien, F Lo, MW Marsden, JE Padberg, K Preis, R Ross, SD Thiere, B AF Dellnitz, M Junge, O Koon, WS Lekien, F Lo, MW Marsden, JE Padberg, K Preis, R Ross, SD Thiere, B TI Transport in dynamical astronomy and multibody problems SO INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS LA English DT Article; Proceedings Paper CT Workshop on Modeling and Computations in Dynamical Systems CY OCT, 2003 CL Budapest, HUNGARY DE three-body problem; transport rates; dynamical systems; almost invariant sets; graph partitioning; set-oriented methods; invariant manifolds; lobe dynamics ID CHEMICAL-REACTION DYNAMICS; RESTRICTED 3-BODY PROBLEM; TRANSITION-STATE THEORY; AREA-PRESERVING MAPS; VARIATIONAL INTEGRATORS; CYLINDRICAL MANIFOLDS; HAMILTONIAN-SYSTEMS; INVARIANT-SETS; SOLAR-SYSTEM; PHASE-SPACE AB We combine the techniques of almost invariant sets (using tree structured box elimination and graph partitioning algorithms) with invariant manifold and lobe dynamics techniques. The result is a new computational technique for computing key dynamical features, including almost invariant sets, resonance regions as well as transport rates and bottlenecks between regions in dynamical systems. This methodology can be applied to a variety of multibody problems, including those in molecular modeling, chemical reaction rates and dynamical astronomy. In this paper we focus on problems in dynamical astronomy to illustrate the power of the combination of these different numerical tools and their applicability. In particular, we compute transport rates between two resonance regions for the three-body system consisting of the Sun, Jupiter and a third body (such as an asteroid). These resonance regions are appropriate for certain comets and asteroids. C1 Univ Paderborn, Fac Comp Sci Elect Engn & Math, D-33095 Paderborn, Germany. CALTECH, Control & Dynam Syst, Pasadena, CA 91125 USA. Princeton Univ, Dept Mech & Aerosp Engn, Princeton, NJ 08544 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Univ Paderborn, Fac Comp Sci Elect Engn & Math, D-33095 Paderborn, Germany. RI Ross, Shane/B-7237-2009; Padberg-Gehle, Kathrin/F-9394-2010 OI Ross, Shane/0000-0001-5523-2376; Padberg-Gehle, Kathrin/0000-0002-1761-213X NR 105 TC 55 Z9 56 U1 1 U2 6 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-1274 EI 1793-6551 J9 INT J BIFURCAT CHAOS JI Int. J. Bifurcation Chaos PD MAR PY 2005 VL 15 IS 3 BP 699 EP 727 DI 10.1142/S0218127405012545 PG 29 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA 927WE UT WOS:000229230400002 ER PT J AU Lucia, DJ Beran, PS AF Lucia, DJ Beran, PS TI Aeroelastic system development using proper orthogonal decomposition and Volterra theory SO JOURNAL OF AIRCRAFT LA English DT Article; Proceedings Paper CT AIAA/ASME/ASCE/AHS/ASC 44th Structures, Structural Dynamics and Materials Conference CY APR 07-10, 2003 CL Norfolk, VA SP AIAA, ASME, ASCE, AHS, ASC ID FLOWS AB Volterra theory and proper orthogonal decomposition are combined into a hybrid methodology for reduced-order modeling of aeroelastic systems. The outcome of the method is a set of linear ordinary differential equations describing the modal amplitudes associated with both the structural modes and the proper orthogonal decomposition basis functions for the fluid. The structural modes are sine waves of varying frequency, and the new approach is applied to the fluid dynamics equations. The structural modes are treated as forcing terms that are impulsed as part of the fluid model realization. By the use of this approach, structural and fluid operators are coupled into a single aeroelastic operator while the parameter (or parameters) of interest for sensitivity analysis are preserved. The approach is applied to an elastic panel in supersonic crossflow. The resulting aeroelastic model provides correct limit-cycle oscillation prediction over a wide range of panel dynamic pressure values. Time integration of the reduced-order aeroelastic model is four orders of magnitude faster than the high-order solution procedure developed by the use of traditional fluid and structural solvers. C1 USAF, Res Lab, AFRL VAS, Wright Patterson AFB, OH 45433 USA. USAF, Res Lab, AFRL VASD, Wright Patterson AFB, OH 45433 USA. NASA, Langley Res Ctr, Aeroelast Branch, Hampton, VA 23681 USA. RP Lucia, DJ (reprint author), USAF, Res Lab, AFRL VAS, Bldg 45,2130 8th St,Suite 1, Wright Patterson AFB, OH 45433 USA. EM david.lucia@wpafb.af.mil; philip.beran@wpafb.af.mil NR 26 TC 7 Z9 7 U1 0 U2 2 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 MAR-APR PY 2005 VL 42 IS 2 BP 509 EP 518 DI 10.2514/1.2176 PG 10 WC Engineering, Aerospace SC Engineering GA 915FS UT WOS:000228284100026 ER PT J AU Shukla, S Agrawal, R Cho, HJ Seal, S Ludwig, L Parish, C AF Shukla, S Agrawal, R Cho, HJ Seal, S Ludwig, L Parish, C TI Effect of ultraviolet radiation exposure on room-temperature hydrogen sensitivity of nanocrystalline doped tin oxide sensor incorporated into microelectromechanical systems device SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SEMICONDUCTOR GAS SENSORS; SENSING PROPERTIES; INDIUM OXIDE; THIN-FILMS; ACTIVATION AB The effect of ultraviolet (UV) radiation exposure on the room-temperature hydrogen (H-2) sensitivity of nanocrystalline indium oxide (In2O3)-doped tin oxide (SnO2) thin-film gas sensor is investigated in this article. The present sensor is incorporated into microelectromechanical systems device using sol-gel dip-coating technique. The present sensor exhibits a very high sensitivity, as high as 65 000-110 000, at room temperature, for 900 ppm of H-2 under the dynamic test condition without UV exposure. The H-2 sensitivity is, however, observed to reduce to 200 under UV radiation, which is contrary to the literature data, where an enhanced room-temperature gas sensitivity has been reported under UV radiation. The observed phenomenon is attributed to the reduced surface coverage by the chemisorbed oxygen ions under UV radiation, which is in consonance with the prediction of the constitutive equation, proposed recently by the authors, for the gas sensitivity of nanocrystalline semiconductor oxide thin-film sensors. (C) 2005 American Institute of Physics. C1 Univ Cent Florida, AMPAC, Orlando, FL 32816 USA. Univ Cent Florida, MMAE Dept, Orlando, FL 32816 USA. NASA, John F Kennedy Space Ctr, Kennedy Space Ctr, FL 32899 USA. RP Seal, S (reprint author), Univ Cent Florida, AMPAC, 4000 Cent Florida Blvd, Orlando, FL 32816 USA. EM sshukla@pegasus.cc.ucf.edu; sseal@pegasus.cc.ucf.edu OI Shukla, Satyajit/0000-0002-7947-8095 NR 22 TC 21 Z9 20 U1 3 U2 7 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 MAR 1 PY 2005 VL 97 IS 5 AR 054307 DI 10.1063/1.1851597 PG 13 WC Physics, Applied SC Physics GA 908DG UT WOS:000227766900054 ER PT J AU Scott, N Hara, T Walsh, EJ Hwang, PA AF Scott, N Hara, T Walsh, EJ Hwang, PA TI Observations of steep wave statistics in open ocean waters SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID BREAKING PROBABILITY; SURFACE-WAVES; PART I; RANGE AB A new wavelet analysis methodology is proposed to estimate the statistics of steep waves. The method is applied to open ocean wave height data from the Southern Ocean Waves Experiment (1992) and from a field experiment conducted at Duck, North Carolina (1997). Results show that high wave slope crests appear over a wide range of wavenumbers. with a large amount being much shorter than the dominant wave. At low wave slope thresholds, all wave fields have roughly the same amount of wave crests regardless 9 of wind forcing. The steep wave statistic decays exponentially with the square of the wave slope threshold, with a decay rate that is larger for the low wind cases than the high wind cases. Comparison of the steep wave statistic with independent measurements of the breaking wave statistic suggests a breaking wave slope threshold of about 0.12. The steep wave statistic does not scale with the cube of the wind speed, suggesting that other factors besides the wind speed also affect its level. Comparison of the steep wave statistic to the saturation spectrum reveals a reasonable correlation at moderate wave slope thresholds. C1 Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. NASA, Goddard Lab Hydrospher Proc, Observ Sci Branch, Wallops Isl, VA USA. Naval Res Lab, Div Oceanog, Stennis Space Ctr, MS USA. RP Scott, N (reprint author), Woods Hole Oceanog Inst, Appl Ocean Phys & Engn, Mail Stop 12,266 Woods Hole Rd, Woods Hole, MA 02543 USA. EM nscott@whoi.edu RI Hara, Tetsu/G-9779-2011 NR 15 TC 6 Z9 6 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD MAR PY 2005 VL 22 IS 3 BP 258 EP 271 DI 10.1175/JTECH1702.1 PG 14 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 911NT UT WOS:000228012000003 ER PT J AU Scott, N Hara, T AF Scott, N Hara, T TI Directionality and crest length statistics of steep waves in open ocean waters SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID PART I; EQUILIBRIUM; SPECTRUM; SURFACE AB A new wavelet analysis methodology is applied to open ocean wave height data from the Southern Ocean Waves Experiment (1992) and from a field experiment conducted at Duck, North Carolina, in 1997 with the aim of estimating the directionality and crest lengths of steep waves. The crest directionality statistic shows that most of the steep wave crests are normal to the direction of the mean wind. This is inconsistent with the Fourier wavenumber spectrum that shows a broad bimodal directional spreading at high wavenumbers. The crest length statistics demonstrate that the wave field is dominated by short-crested waves with small crest length/wave length ratios. The one-dimensional steep wave statistic obtained from the integration of the directional (two dimensional) steep wave statistic is consistent with the one-dimensional steep wave statistic obtained from the one-dimensional analysis at high wave slope thresholds. C1 Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Univ Rhode Isl, Grad Sch Oceanog, Narragansett, RI 02882 USA. Naval Res Lab, Div Oceanog, Stennis Space Ctr, MS USA. NASA, Goddard Lab Hydrospher Proc, Observ Sci Branch, Wallops Isl, VA USA. RP Scott, N (reprint author), Woods Hole Oceanog Inst, Mail Stop 12,266 Woods Hole Rd, Woods Hole, MA 02543 USA. EM nscott@whoi.edu RI Hara, Tetsu/G-9779-2011 NR 10 TC 3 Z9 3 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD MAR PY 2005 VL 22 IS 3 BP 272 EP 281 DI 10.1175/JTECH1703.1 PG 10 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 911NT UT WOS:000228012000004 ER PT J AU Tu, JN Horwitz, JL Moore, TE AF Tu, JN Horwitz, JL Moore, TE TI Simulating the cleft ion fountain at polar perigee altitudes SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article DE dynamic fluid semi-kinetic simulation; field-aligned ion transport; cleft ion fountain; day-night asymmetry of ion density ID PARALLEL ELECTRIC-FIELDS; TOPSIDE IONOSPHERE; PLASMA TRANSPORT; CURRENT REGION; WIND; MODEL; OUTFLOW; MAGNETOSPHERE; PRECIPITATION; ACCELERATION AB A dynamic fluid semi-kinetic (DyFK) model is used to simulate the cleft ion fountain. Ion field-aligned flows are modeled for a flux tube convecting along an empirical model specified convection trajectory across the polar ionosphere from the cusp/cleft region. In this DyFK model, the collision-dominated portion of the flux tube is treated with a moment-based fluid model for altitudes from 120 to 1100 km, while a generalized semi-kinetic model is used for the 800km to 3 RE altitude region. Convection-driven frictional ion heating and the effects of cusp/cleft soft electron precipitation in the F region/topside ionosphere, and centrifugal acceleration of ions and wave-driven transverse ion heating at high altitudes, are incorporated into the present simulations of the ion field-aligned transport. The modeled evolution of the O+ flow parameters at 5500km altitude exhibits typical patterns for the cleft ion fountain: O+ field-aligned flows are upward over the dayside cusp/cleft and remain upward for 5 or more degrees latitude into the polar cap, with decreasing magnitude towards the pole; the flows turn downward at about 86 degrees invariant latitude and tend to increase in magnitude (downward) across the polar cap from dayside to nightside; the O+ density also displays apparent day-night asymmetry with higher density on the dayside. The simulated field-aligned flow pattern is in qualitative agreement with the observations from the thermal ion dynamics experiment (TIDE) during a Polar satellite southern perigee pass. The simulated ion densities and field-aligned fluxes are in general consistent with those observed. It is also shown in systematic simulations that the day-night asymmetry of the O+ density across the polar cap from dayside to nightside may be directly controlled by the cleft ion fountain, while the H+ density asymmetry is probably caused by day-night variations in solar illumination. (c) 2005 Elsevier Ltd. All rights reserved. C1 Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. Univ Alabama, Ctr Space Plasma & Aeron Res, Huntsville, AL 35899 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Univ Alabama, Dept Phys, Huntsville, AL 35899 USA. EM Jiannan_Tu@uml.edu RI Moore, Thomas/D-4675-2012 OI Moore, Thomas/0000-0002-3150-1137 NR 50 TC 16 Z9 16 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 EI 1879-1824 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD MAR PY 2005 VL 67 IS 5 BP 465 EP 477 DI 10.1016/j.jastp.2004.11.009 PG 13 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 905CB UT WOS:000227544100004 ER PT J AU Pyatt, HE Albrecht, BA Fairall, C Hare, JE Bond, N Minnis, P Ayers, JK AF Pyatt, HE Albrecht, BA Fairall, C Hare, JE Bond, N Minnis, P Ayers, JK TI Evolution of marine atmospheric boundary layer structure across the cold tongue-ITCZ complex SO JOURNAL OF CLIMATE LA English DT Article ID EASTERN EQUATORIAL PACIFIC; SEA-SURFACE TEMPERATURE; THERMODYNAMIC STRUCTURE; VARIABILITY; WIND; CLOUDINESS; INVERSION AB The structure of the marine atmospheric boundary layer (MABL) over the tropical eastern Pacific Ocean is influenced by spatial variations of sea surface temperature (SST) in the region. As the MABL air is advected across a strong SST gradient associated with the cold tongue-ITCZ complex (CTIC), substantial changes occur in the thermodynamic structure, surface fluxes, and cloud properties. This study attempts to define and explain the variability in the MABL structure and clouds over the CTIC. Using data collected on research cruises from the fall seasons of 1999-2001, composite soundings were created for both the cold and warm sides of the SST front to describe the mean atmospheric boundary layer (ABL) structure and its evolution across this front. The average difference in SST across this front was similar to 6 degrees C; much of this difference was concentrated in a band only similar to 50 km wide. During the fall seasons, on the cold side of the gradient, a well-defined inversion exists in all years. Below this inversion, both fair-weather cumulus and stratiform clouds are observed. As the MABL air moves over the SST front to warmer waters, the inversion weakens and increases in height. The MABL also moistens and eventually supports deeper convection over the ITCZ. Both the latent and sensible heat fluxes increase dramatically across the SST front because of both an increase in SST and surface wind speed. Cloudiness is variable on the cold side of the SST front ranging from 0.2 to 0.9 coverage. On the warm side, cloud fraction was quite constant in time, with values generally greater than 0.8. The highest cloud-top heights (> 3 km) are found well north of the SST front, indicating areas of deeper convection. An analysis using energy and moisture budgets identifies the roles of various physical processes in the MABL evolution. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Meteorol & Phys Oceanog, Miami, FL 33149 USA. NOAA, ETL, Boulder, CO 80303 USA. Univ Washington, JISAO, Seattle, WA 98195 USA. NASA, Langley Res Ctr, Div Atmospher Sci, Hampton, VA 23665 USA. Analyt Sci & Mat Inc, Hampton, VA USA. RP Albrecht, BA (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Div Meteorol & Phys Oceanog, 4600 Rickenbacker Causeway, Miami, FL 33149 USA. EM balbrecht@rsmas.miami.edu RI Minnis, Patrick/G-1902-2010 OI Minnis, Patrick/0000-0002-4733-6148 NR 22 TC 21 Z9 21 U1 0 U2 1 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 MAR 1 PY 2005 VL 18 IS 5 BP 737 EP 753 DI 10.1175/JCLI-3287.1 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 909RQ UT WOS:000227878800009 ER PT J AU Hogue, MD Mucciolo, ER Calle, CI Buhler, CR AF Hogue, MD Mucciolo, ER Calle, CI Buhler, CR TI Two-phase equilibrium model of insulator-insulator contact charging with electrostatic potential SO JOURNAL OF ELECTROSTATICS LA English DT Article; Proceedings Paper CT Annual Conference of the Electrostatics-Society-of-America CY JUN 23-25, 2004 CL Rochester, NY SP Electrostat Soc Amer DE contact charging; triboelectrification; equilibrium model; insulator AB A two-phase equilibrium model based on an ideal gas of singly charged ions in equilibrium with a submonolayer adsorbed film was developed to describe the pressure dependence of insulator-insulator contact charging. Experimental data show that the surface charge density decreases with respect to pressure for insulators as pressure is lowered. In this work, the gas phase of the two-phase model is extended to consider the electrostatic coulombic and screening potentials from the surface. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Electrostat & Surface Phys Lab, Kennedy Space Ctr, FL 32899 USA. Univ Cent Florida, Dept Phys, Orlando, FL 32816 USA. ASRC Aerosp, Kennedy Space Ctr, FL 32899 USA. RP Hogue, MD (reprint author), NASA, Electrostat & Surface Phys Lab, YA-C2-T, Kennedy Space Ctr, FL 32899 USA. EM michael.d.hogue@nasa.gov NR 7 TC 18 Z9 18 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3886 J9 J ELECTROSTAT JI J. Electrost. PD MAR PY 2005 VL 63 IS 3-4 BP 179 EP 188 DI 10.1016/j.elstat.2004.09.003 PG 10 WC Engineering, Electrical & Electronic SC Engineering GA 900OV UT WOS:000227225100002 ER PT J AU Kaufmann, G Wu, P Ivins, ER AF Kaufmann, G Wu, P Ivins, ER TI Lateral viscosity variations beneath Antarctica and their implications on regional rebound motions and seismotectonics SO JOURNAL OF GEODYNAMICS LA English DT Article; Proceedings Paper CT Joint Assembly of the EGS/AGU/EUG CY APR 06-11, 2003 CL Nice, FRANCE SP EGS, AGU, EUG DE Antarctic Ice Sheet; glacial isostatic adjustment; present-day motions; faulting ID GLACIAL ISOSTATIC-ADJUSTMENT; SEA-LEVEL CHANGE; COMPUTING 3-DIMENSIONAL DEFORMATIONS; UPPER-MANTLE; ICE-SHEET; LATE PLEISTOCENE; MARCH 25; HETEROGENEOUS EARTH; SPECTRAL FORMALISM; PLATE EARTHQUAKE AB The Antarctic Ice Sheet has experienced large ice volume changes during the late Pleistocene glacial cycles. However, the exact amount and areas of mass change are difficult to establish, as both glaciological reconstructions and climate models rely on relatively sparse data sets, when compared to Northern Hemisphere data. We assess the potential contributions to present-day crustal motions and seismicity from glacially-induced ice mass changes. Three different scenarios for the late-Pleistocene ice-sheet distributions are considered. The viscoelastic response of the bedrock is computed for two earth models, a model with radially varying mantle viscosity only, and a model with three-dimensional viscosity variations based on a recent seismic tomographical study. In the latter model, East Antarctica is underlain by a stiff cratonic root, while the upper mantle underneath West Antarctica is weak. Our predicted present-day crustal motions depend strongly on the ice model chosen, with vertical motions focused on areas of former late Pleistocene ice domes. The horizontal motions are greatly affected by the earth theology, as the horizontal flow pattern is controlled by the flow from the stiff East Antarctic cratonic root to the weaker West Antarctic mantle. Glacially-induced changes in fault stability margin are positive over much of Antarctica, indicating a seismically quiet state due to the large present-day ice sheet. At the site of the 1998 Balleny Island Earthquake (M(W) = 8.1), the stresses are relatively small by comparison, and interestingly become more prone to stress failure, when a three-dimensional earth model is assumed. (C) 2004 Elsevier Ltd. All rights reserved. C1 Univ Gottingen, Inst Geophys, D-37075 Gottingen, Germany. Univ Calgary, Dept Geol & Geophys, Calgary, AB T2N 1N4, Canada. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kaufmann, G (reprint author), Univ Gottingen, Inst Geophys, Herzberger Landstr 180, D-37075 Gottingen, Germany. EM gkaufman@uni-geophys.gwdg.de RI Wu, Patrick/F-4194-2010 OI Wu, Patrick/0000-0001-5812-4928 NR 69 TC 42 Z9 43 U1 2 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0264-3707 J9 J GEODYN JI J. Geodyn. PD MAR PY 2005 VL 39 IS 2 BP 165 EP 181 DI 10.1016/j.jog.2004.08.009 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 900BF UT WOS:000227189700007 ER PT J AU Jeong, MJ Li, ZQ Chu, DA Tsay, SC AF Jeong, MJ Li, ZQ Chu, DA Tsay, SC TI Quality and compatibility analyses of global aerosol products derived from the advanced very high resolution radiometer and Moderate Resolution Imaging Spectroradiometer SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INDIVIDUAL AVHRR CHANNELS; OPTICAL DEPTH; SIZE DISTRIBUTION; DUST AEROSOL; SATELLITE MEASUREMENTS; RETRIEVAL ALGORITHM; CONSISTENCY CHECKS; RADIATIVE-TRANSFER; ANGSTROM EXPONENT; SOUTHERN AFRICA AB There exist numerous global aerosol products derived from various satellite sensors, but little insight has been gained about their compatibility and quality. This study presents a comparison of two prominent global aerosol products derived over oceans from the advanced very high resolution radiometer (AVHRR) under the Global Aerosol Climatology Project (GACP) (Mishchenko et al., 1999) and the Moderate Resolution Imaging Spectroradiometer ( MODIS) ( Tanre et al., 1997). The comparisons are for monthly mean aerosol optical thickness (AOT) and angstrom ngstrom exponent (alpha) at a spatial resolution of 1 x 1 degree. The two monthly AOT products showed substantial discrepancies, with a tendency of higher values from MODIS than from GACP/AVHRR, especially near the coasts of major aerosol outbreak regions. Individual monthly AOT values have poor correlation, but their regional means are moderately correlated ( correlation coefficient 0.5 < R < 1.0). While cloud screening has often been argued to be a major factor explaining large discrepancies, this study shows that differences in aerosol models in the two retrieval algorithms can lead to large discrepancies. Contributions of the size distribution are more significant than the refractive index. The noisiness of the GACP/AVHRR aerosol retrievals seem to be partially influenced by radiometric uncertainties in the AVHRR system, but it is unlikely a major factor to explain the observed systematic discrepancies between the MODIS and GACP/AVHRR AOTs. For alpha, correlations between MODIS and GACP/AVHRR are lower (0.2 < R < 0.7) than AOT. The MODIS alpha shows a well-behaved dependence on the AOT contingent upon the aerosol type, while the GACP/AVHRR alpha has little correlation with the AOT. The high sensitivity in the selection of aerosol models to radiometric errors may be a primary reason for the worse comparison of alpha. Part of the discrepancies in a is attributed to different aerosol size distributions. C1 Univ Maryland, Dept Meteorol & Earth Syst, Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Chinese Acad Sci, Inst Atmospher Phys, Beijing, Peoples R China. RP Univ Maryland, Dept Meteorol & Earth Syst, Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. EM mjeong@atmos.umd.edu; zli@atmos.umd.edu; achu@climate.gsfc.nasa.gov; tsay@climate.gsfc.nasa.gov RI Jeong, Myeong/B-8803-2008; Li, Zhanqing/F-4424-2010; Tsay, Si-Chee/J-1147-2014 OI Li, Zhanqing/0000-0001-6737-382X; NR 69 TC 54 Z9 54 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 MAR 1 PY 2005 VL 110 IS D10 AR D10S09 DI 10.1029/2004JD004648 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 905EO UT WOS:000227551000001 ER PT J AU Omar, AH Won, JG Winker, DM Yoon, SC Dubovik, O McCormick, MP AF Omar, AH Won, JG Winker, DM Yoon, SC Dubovik, O McCormick, MP TI Development of global aerosol models using cluster analysis of Aerosol Robotic Network (AERONET) measurements SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SKY RADIANCE MEASUREMENTS; INDIAN-OCEAN EXPERIMENT; OPTICAL-PROPERTIES; TROPOSPHERIC AEROSOLS; 6-WAVELENGTH LIDAR; SIZE DISTRIBUTION; LIGHT-SCATTERING; MINERAL DUST; CLIMATE; RETRIEVAL AB We use radiance measurements and inversions of the Aerosol Robotic Network (AERONET) (Dubovik and King, 2000; Holben et al., 1998; Holben et al., 2001) to classify global atmospheric aerosols using the complete archive of the AERONET data set as of December 2002 and dating back to 1993 for some sites. More than 143,000 records of AERONET solar radiance measurements, derived aerosol size distributions, and complex refractive indices are used to generate the optical properties of the aerosol at more than 250 sites worldwide. Each record is used in a clustering algorithm as an object, with 26 variables comprising both microphysical and optical properties to obtain six significant clusters. Using the mean values of the optical and microphysical properties together with the geographic locations, we identified these clusters as desert dust, biomass burning, urban industrial pollution, rural background, polluted marine, and dirty pollution. When the records in each cluster are subdivided by optical depth class, the trends of the class size distributions show that the extensive properties ( mode amplitude and total volume) vary by optical depth, while the intensive properties ( mean radius and standard deviation) are relatively constant. Seasonal variations of aerosol types are consistent with observed trends. In particular, the periods of intense biomass burning activity and desert dust generation can be discerned from the data and the results of the analyses. Sensitivity and uncertainty analyses show that the clustering algorithm is quite robust. When subsets of the data set are randomly created and the clustering algorithm applied, we found that more than 94% of the records retain their classification. Adding 10% random noise to the microphysical properties and propagating this error through the scattering calculations, followed by the clustering algorithm, results in a misclassification rate of less than 9% when compared with the noise-free data. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. Seoul Natl Univ, Sch Earth & Environm Sci, Seoul 151747, South Korea. RP NASA, Langley Res Ctr, MS 401 A, Hampton, VA 23681 USA. EM ali.h.omar@nasa.gov RI Dubovik, Oleg/A-8235-2009; Omar, Ali/D-7102-2017 OI Dubovik, Oleg/0000-0003-3482-6460; Omar, Ali/0000-0003-1871-9235 NR 36 TC 128 Z9 132 U1 4 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 MAR 1 PY 2005 VL 110 IS D10 AR D10S14 DI 10.1029/2004JD004874 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 905EO UT WOS:000227551000002 ER PT J AU Grenon, SM Hurwitz, S Xiao, XS Sheynberg, N Ramsdell, CD Kim, C Cohen, RJ Williams, GH AF Grenon, SM Hurwitz, S Xiao, XS Sheynberg, N Ramsdell, CD Kim, C Cohen, RJ Williams, GH TI Readaptation from simulated microgravity as a stimulus for improved orthostatic tolerance: Role of the renal, cardioendocrine, and cardiovascular systems SO JOURNAL OF INVESTIGATIVE MEDICINE LA English DT Article DE recovery; simulated microgravity; renin-angiotensinaldosterone system ID DOWN BED REST; SHORT-DURATION SPACEFLIGHT; RESPONSES; INTOLERANCE; TILT; HUMANS; HYPOTENSION; ENDOCRINE; PRESSURE; IDENTIFICATION AB Background: Microgravity and simulated microgravity (SM) lead to important changes in orthostatic tolerance (OT), the autonomic nervous system (ANS), and the volume-regulating systems. After one is exposed to microgravity or SM, a period of readaptation to gravity is known to take place, but it is not certain if orthostatic function returns to baseline within the initial recovery and what mechanisms are involved. We hypothesized that after a period of recovery, OT, ANS, and volume-regulating systems would return to pre-SM levels. Methods: To test this hypothesis, 24 healthy men were placed on a constant diet for 3 to 5 days, after which a tilt-stand test (pre-TST) was performed. The TST was repeated after 14 to 16 days of head-down tilt bed rest (HDTB) (post-TST) and a 3-day period of recovery (rec-TST), at which times measurements of renal, cardioendocrine, and cardiovascular systems were conducted. Results: Presyncope occurred in 46% of subjects pre-TST, in 72% post-TST, and in 23% during rec-TST. OT was significantly better during the recovery period than at baseline (p = .03). There was a significant decrease in urinary sodium and potassium excretion, along with a decrease in plasma renin activity and serum and urine aldosterone compared with baseline. Serum norepinephrine and sympathetic responsiveness remained below baseline values. Conclusion: In summary, OT improved compared with baseline after a period of readaptation. Retention of electrolytes (sodium, potassium) could be involved. These findings indicate that recovery after SM is not simply a gradual return to baseline values but is instead a dynamic process reflecting interaction of multiple regulatory systems. C1 Brigham & Womens Hosp, Div Endocrinol Hypertens & Diabet, Boston, MA 02115 USA. NASA, Ctr Quantitat Cardiovasc Physiol Modeling & Data, Cambridge, MA USA. Harvard Univ, MIT, Div Hlth Sci & Technol, Cambridge, MA USA. McGill Univ, Dept Cardiothorac Surg, Montreal, PQ, Canada. RP Williams, GH (reprint author), Brigham & Womens Hosp, Div Endocrinol Hypertens & Diabet, 221 Longwood Ave, Boston, MA 02115 USA. EM gwilliams@partners.org FU NCRR NIH HHS [5M01RR02635] NR 53 TC 3 Z9 4 U1 0 U2 1 PU B C DECKER INC PI HAMILTON PA 20 HUGHSON ST SOUTH, PO BOX 620, L C D 1, HAMILTON, ONTARIO L8N 3K7, CANADA SN 1081-5589 J9 J INVEST MED JI J. Invest. Med. PD MAR PY 2005 VL 53 IS 2 BP 82 EP 91 PG 10 WC Medicine, General & Internal; Medicine, Research & Experimental SC General & Internal Medicine; Research & Experimental Medicine GA 909FU UT WOS:000227846600016 PM 15810494 ER PT J AU Wright, MW Valley, GC AF Wright, MW Valley, GC TI Yb-doped fiber amplifier for deep-space optical communications SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article DE optical communications; optical fiber amplifier AB A custom-developed high-power laser based on a Yb-doped amplifier is characterized as a transmitter for deep-space optical communications. The key requirements are high peak power at moderate data rates with good beam quality. The transient pulse dynamics are modeled via a simple rate equation approach and reveal a qualitative agreement with the pulsed performance. Peak powers were obtained up to 8 kW for a 22-ns pulsewidth at a 3.5-kHz repetition rates. The peak power dropped significantly as the repetition rate was increased to 50 kHz. C1 CALTECH, Jet Prop Lab, Opt Commun Grp, Pasadena, CA 91109 USA. Aerosp Corp, Elect & Photon Lab, El Segundo, CA 90245 USA. RP Wright, MW (reprint author), CALTECH, Jet Prop Lab, Opt Commun Grp, Pasadena, CA 91109 USA. NR 9 TC 27 Z9 33 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD MAR PY 2005 VL 23 IS 3 BP 1369 EP 1374 DI 10.1109/JLT.2005.843532 PG 6 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA 915LD UT WOS:000228304800050 ER PT J AU Tsai, T AF Tsai, T TI New analytical model of bolted joints (vol 126, page 721, 2004) SO JOURNAL OF MECHANICAL DESIGN LA English DT Editorial Material C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Tsai, T (reprint author), NASA, Lyndon B Johnson Space Ctr, Mail Code ES5,2101 NASA Rd 1, Houston, TX 77058 USA. EM ted.w.tsai@nasa.gov NR 1 TC 0 Z9 0 U1 0 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 1050-0472 J9 J MECH DESIGN JI J. Mech. Des. PD MAR PY 2005 VL 127 IS 2 BP 352 EP 352 DI 10.1115/1.1858928 PG 1 WC Engineering, Mechanical SC Engineering GA 921RI UT WOS:000228781900024 ER PT J AU Smith, SM Zwart, SR Block, G Rice, BL Davis-Street, JE AF Smith, SM Zwart, SR Block, G Rice, BL Davis-Street, JE TI The nutritional status of astronauts is altered after long-term space flight aboard the International Space Station SO JOURNAL OF NUTRITION LA English DT Article DE space flight; nutritional status; humans; bone resorption; weightlessness ID INDUCED BONE LOSS; RED-BLOOD-CELL; BED REST; VITAMIN-D; CALCIUM-ABSORPTION; ENERGY-EXPENDITURE; SPACEFLIGHT; MARKERS; METABOLISM; TURNOVER AB Defining optimal nutrient requirements is critical for ensuring crew health during long-duration space exploration missions. Data pertaining to such nutrient requirements are extremely limited. The primary goal of this study was to better understand nutritional changes that occur during long-duration space flight. We examined body composition, bone metabolism, hematology, general blood chemistry, and blood levels of selected vitamins and minerals in 11 astronauts before and after long-duration (128-195 d) space flight aboard the International Space Station. Dietary intake and limited biochemical measures were assessed during flight. Crew members consumed a mean of 80% of their recommended energy intake, and on landing day their body weight was less (P = 0.051) than before flight. Hematocrit, serum iron, ferritin saturation, and transferrin were decreased and serum ferritin was increased after flight (P < 0.05). The finding that other acute-phase proteins were unchanged after flight suggests that the changes in iron metabolism are not likely to be solely a result of an inflammatory response. Urinary 8-hydroxy-2'-deoxyguanosine concentration was greater and RBC superoxide dismutase was less after flight (P < 0.05), indicating increased oxidative damage. Despite vitamin D supplement use during flight, serum 25-hydroxycholecalciferol was decreased after flight (P < 0.01). Bone resorption was increased after flight, as indicated by several markers. Bone formation, assessed by several markers, did not consistently rise 1 d after landing. These data provide evidence that bone loss, compromised vitamin D status, and oxidative damage are among critical nutritional concerns for long-duration space travelers. C1 NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Off, Houston, TX 77058 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Enterprise Advisory Serv Inc, Houston, TX 77058 USA. RP Smith, SM (reprint author), NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Off, Houston, TX 77058 USA. EM scott.m.smith@nasa.gov RI Block, Gladys/E-3304-2010 NR 46 TC 105 Z9 109 U1 0 U2 15 PU AMER INST NUTRITION PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0022-3166 J9 J NUTR JI J. Nutr. PD MAR PY 2005 VL 135 IS 3 BP 437 EP 443 PG 7 WC Nutrition & Dietetics SC Nutrition & Dietetics GA 904PF UT WOS:000227509500013 PM 15735075 ER PT J AU Smorawinski, J Mlynarczyk, C Ziemba, AW Mikulski, T Cybulski, G Grucza, R Nazar, K Kaciuba-Uscilko, H Greenleaf, JE AF Smorawinski, J Mlynarczyk, C Ziemba, AW Mikulski, T Cybulski, G Grucza, R Nazar, K Kaciuba-Uscilko, H Greenleaf, JE TI Exercise training and 3-day head down bed rest deconditioning: Exercise thermoregulation SO JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY LA English DT Article DE core temperature; skin temperature; sweating rate; microgravity ID SKIN BLOOD-FLOW; TILT; RESPONSES; HUMANS; MEN; BODY AB Bed rest (BR) deconditioning causes excessive increase of exercise core body tempera-ture, while aerobic training improves exercise thermoregulation. The study was designed to determine whether 3 days of 6 degrees head-down bed rest (HDBR) affects body temperature and sweating dynamics during exercise and, if so, whether endurance training before HDBR modifies these responses. Twelve healthy men (20.71 +/- 0.9 yrs, VO(2)max: 46 +/- 4 ml(.)kg(-1.)min(-1)) underwent HDBR twice: before and after 6 weeks of endurance training. Before and after HDBR, the subjects performed 45 min sitting cycle exercise at the same workload equal to 60% of VO(2)max determined before training. During exercise the VO2 HR, tympanic (Ttymp) and skin (Tsk) temperatures were recorded; sweating dynamics was assayed from a ventilated capsule on chest. Training increased VO(2)max by 12.1% (p < 0.001). Resting Ttymp increased only after first HDBR (by 0.22 +/- 0.08 degrees C, p < 0.05), while exercise equilibrium levels of Ttymp were increased (p < 0.05) by 0.21 +/- 0.07 and 0.26 +/- 0.08 degrees C after first and second HDBR, respectively. Exercise mean Tsk tended to be lower after both HDBR periods. Total sweat loss and time-course of sweating responses were similar in all exercise tests. The sweating threshold related to Ttymp was elevated (p < 0.05) only after first HDBR. In conclusion: six-week training regimen prevents HDBR-induced elevation of core temperature (Ttymp) at rest but not during ex-ercise. The post-HDBR increases of Ttymp without changes in sweating rate and the tendency for lower Tsk suggest an early (< 3d) influence of BR on skin blood flow. 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 Smorawinski, J (reprint author), Polish Acad Sci, Dept Appl Physiol, Med Res Ctr, 5 Pawinskiego Str, PL-02106 Warsaw, Poland. EM nazar@cmdik.pan.pl RI Grucza, Ryszard/H-7593-2014 NR 28 TC 1 Z9 1 U1 1 U2 2 PU POLISH PHYSIOLOGICAL SOC PI GRZEGORZECKA PA JAGIELLONIAN UNIV SCHOOL MED, INST PHYSIOLOGY, 31-531 KRAKOW, 16 GRZEGORZECKA, POLAND SN 0867-5910 J9 J PHYSIOL PHARMACOL JI J. Physiol. Pharmacol. PD MAR PY 2005 VL 56 IS 1 BP 101 EP 110 PG 10 WC Physiology SC Physiology GA 910IQ UT WOS:000227925000008 PM 15795478 ER PT J AU Tessler, A Sleight, DW Wang, JT AF Tessler, A Sleight, DW Wang, JT TI Effective modeling and nonlinear shell analysis of thin membranes exhibiting structural wrinkling SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article AB Thin solar sail membranes of very large span are being envisioned for near-term space missions. One major design issue that is inherent to these very flexible structures is the formation of wrinkling patterns. Structural wrinkles may deteriorate a solar sail's performance and, in certain cases, structural integrity. A geometrically nonlinear, updated Lagrangian shell formulation is employed using the ABAQUS finite element code to simulate the formation of wrinkled deformations in thin-film membranes. The restrictive assumptions of true membranes as defined by tension field theory are not invoked. Two effective modeling strategies are introduced to facilitate convergent solutions of wrinkled equilibrium states. They include 1) the application of small, pseudorandom, out-of-plane geometric imperfections that ensure initiation of the requisite membrane-to-bending coupling in a geometrically nonlinear analysis and 2) the truncation of corner regions, where concentrated loads are prescribed, to improve load transfer, mesh quality, and kinematics and to reduce severe concentration of membrane stresses. The corner truncation necessitates replacing the concentrated force with a statically equivalent distributed traction. Several numerical studies are carried out, and the results are compared with recent experimental data. Good agreement is observed between the numerical simulations and experimental data. C1 NASA, Langley Res Ctr, Analyt & Computat Methods Branch, Hampton, VA 23681 USA. RP Tessler, A (reprint author), NASA, Langley Res Ctr, Analyt & Computat Methods Branch, Hampton, VA 23681 USA. RI Tessler, Alexander/A-4729-2009 NR 24 TC 35 Z9 36 U1 0 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 MAR-APR PY 2005 VL 42 IS 2 BP 287 EP 298 DI 10.2514/1.3915 PG 12 WC Engineering, Aerospace SC Engineering GA 916VL UT WOS:000228414400011 ER PT J AU Panzarella, CH Kassemi, M AF Panzarella, CH Kassemi, M TI Self-pressurization of large spherical cryogenic tanks in space SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID MICROGRAVITY AB The pressurization of large cryogenic storage tanks under microgravity conditions is investigated by coupling a lumped thermodynamic model of the vapor region with a complete solution of the flow and temperature fields in the liquid. Numerical results indicate that in microgravity both buoyancy and natural convection are still important and play a significant role in phase distribution and tank pressurization. A spherical vapor region initially placed at the center of the tank deforms and moves to one side of the tank before any significant pressure rise. Long-term results obtained with the vapor region near the tank wall show that, even in microgravity, natural convection leads to thermal stratification in the liquid and significantly alters the initial pressure rise. The final rate of pressure rise agrees with a lumped thermodynamic model of the entire system, but the final pressure levels depart from thermodynamic predictions because of initial transients. The history of the maximum liquid superheat and subcooling is also determined for each configuration. C1 Ohio Aerosp Inst, Cleveland, OH 44142 USA. NASA, John H Glenn Res Ctr Lewis Field, Natl Ctr Micrograv Res, Cleveland, OH 44135 USA. RP Panzarella, CH (reprint author), Ohio Aerosp Inst, 22800 Cedar Point Rd, Cleveland, OH 44142 USA. EM Charles.H.Panzarella@grc.nasa.gov NR 29 TC 7 Z9 14 U1 1 U2 7 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 MAR-APR PY 2005 VL 42 IS 2 BP 299 EP 308 DI 10.2514/1.4571 PG 10 WC Engineering, Aerospace SC Engineering GA 916VL UT WOS:000228414400012 ER PT J AU Hall, JL Noca, MA Bailey, RW AF Hall, JL Noca, MA Bailey, RW TI Cost-benefit analysis of the aerocapture mission set SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID AEROBRAKING AB Calculations have been performed to quantify the cost and delivered mass advantages of aerocapture at all destinations in the solar system with significant atmospheres. A total of 11 representative missions were defined for the eight possible destinations and complete launch-to-orbit insertion architectures constructed based on available U.S. launch vehicles. Direct comparisons were made between aerocapture and competing orbit insertion techniques based on state-of-the-art and advanced chemical propulsion, solar electric propulsion, and aerobraking. The results show that three of the missions cannot be done without aerocapture: delivery of spacecraft into elliptical orbits at Neptune and circular orbits at Jupiter or Saturn. Aerocapture was found to significantly enhance five other missions by putting larger, and usually very much larger, spacecraft into the target orbit for approximately the same overall delivery cost as the best nonaerocapture alternative: delivery of spacecraft into Venus circular orbits (79% more mass), Venus elliptical orbits (43%), Mars circular orbits (15%), Titan circular orbits (280%), and Uranus elliptical orbits (218%). These results, and other delivery cost per unit delivered mass metrics, were found to be not very sensitive to 30% increases in both the estimated aerocapture system mass and system cost, suggesting that even modestly performing aerocapture systems will yield substantial mission benefits. Two other missions consisting of spacecraft inserted into high-eccentricity elliptical orbits at Mars and Jupiter were shown to be not improved by aerocapture. The last mission in the set consisting of an aeroassisted orbit transfer at Earth showed that aerocapture technology offered a 32% $/kg reduction compared to chemical propulsion, but that aerobraking offered even better performance. Nevertheless, the problems of repeated passes through the Van Allen radiation belts are likely to preclude Earth aerobraking for most applications. C1 CALTECH, Jet Prop Lab, Avion Syst & Technol Div, Pasadena, CA 91109 USA. CALTECH, Jet Prop Lab, Syst Div, Pasadena, CA 91109 USA. RP Hall, JL (reprint author), CALTECH, Jet Prop Lab, Avion Syst & Technol Div, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 18 TC 15 Z9 16 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 MAR-APR PY 2005 VL 42 IS 2 BP 309 EP 320 DI 10.2514/1.4118 PG 12 WC Engineering, Aerospace SC Engineering GA 916VL UT WOS:000228414400013 ER PT J AU O'Donnell, JR Davis, GT Ward, DK AF O'Donnell, JR Davis, GT Ward, DK TI Restoring redundancy to the Wilkinson Microwave Anisotropy Probe propulsion system SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID DESIGN AB The Wilkinson Microwave Anisotropy Probe is a follow-on to the differential microwave radiometer instrument on the Cosmic Background Explorer. Attitude control system engineers discovered 16 months before launch that configuration changes after the critical design review had resulted in a significant migration of the spacecraft's center of mass. As a result, the spacecraft no longer had a viable backup control mode in the event of a failure of the negative pitch-axis thruster. A tiger team was formed and identified potential solutions to this problem, such as adding thruster-plume shields to redirect thruster torque, adding or removing mass from the spacecraft, adding an additional thruster, moving thrusters, bending thruster nozzles or propellant tubing, or accepting the loss of redundancy. The project considered the impacts on mass, cost, fuel budget, and schedule for each solution and it was decided to bend the propellant tubing of the two roll-control thrusters to allow the pair to be used for backup control in the negative pitch axis. The problem and the potential solutions are discussed, and the hardware and software changes and performed verification are documented. Flight data are presented to show the on-orbit performance of the propulsion system and lessons learned are described. C1 NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Syst Engn Branch, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Prop Branch, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Space Sci Miss Branch, Greenbelt, MD 20771 USA. RP O'Donnell, JR (reprint author), NASA, Goddard Space Flight Ctr, Guidance Navigat & Control Syst Engn Branch, Greenbelt, MD 20771 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD MAR-APR PY 2005 VL 42 IS 2 BP 336 EP 344 DI 10.2514/1.9435 PG 9 WC Engineering, Aerospace SC Engineering GA 916VL UT WOS:000228414400016 ER PT J AU Newman, PA Nash, ER AF Newman, PA Nash, ER TI The unusual Southern Hemisphere stratosphere winter of 2002 SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID INTERNAL INTERANNUAL VARIABILITY; QUASI-BIENNIAL OSCILLATION; PLANETARY-WAVES; SATELLITE DATA; OZONE; TEMPERATURE; PROPAGATION; CIRCULATION; TROPOSPHERE; REANALYSIS AB The Southern Hemisphere (SH) stratospheric winter of 2002 was the most unusual winter yet observed in the SH climate record. Temperatures near the edge of the Antarctic polar vortex were considerably warmer than normal over the entire course of the winter. The polar night jet was considerably weaker than normal and was displaced more poleward than has been observed in previous winters. These record high temperatures and weak jet resulted from a series of wave events that took place over the course of the winter. The propagation of these wave events from the troposphere is diagnosed from time series of Eliassen-Palm flux vectors and autoregression time series. Strong levels of planetary waves were observed in the midlatitude lower troposphere. The combinations of strong tropospheric waves with a low index of refraction at the tropopause resulted in the large stratospheric wave forcing. The wave events tended to occur irregularly over the course of the winter, and the cumulative effect of these waves was to precondition the polar night jet for the extremely large wave event of 22 September. This large wave event resulted in the first ever observed major stratospheric warming in the SH and split the Antarctic ozone hole. The combined effect of all of the 2002 winter wave events resulted in the smallest ozone hole observed since 1988. The sequence of stratospheric wave events was also found to be strongly associated with unusually strong levels of wave I in the SH tropospheric subtropics. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Landover, MD USA. RP NASA, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA. EM newman@code916.gsfc.nasa.gov RI Newman, Paul/D-6208-2012 OI Newman, Paul/0000-0003-1139-2508 NR 28 TC 86 Z9 88 U1 1 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR PY 2005 VL 62 IS 3 BP 614 EP 628 DI 10.1175/JAS-3323.1 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 911NU UT WOS:000228012100006 ER PT J AU Harnik, N Scott, RK Perlwitz, J AF Harnik, N Scott, RK Perlwitz, J TI Wave reflection and focusing prior to the major stratospheric warming of September 2002 SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SOUTHERN-HEMISPHERE STRATOSPHERE; PLANETARY-SCALE DISTURBANCES; QUASI-BIENNIAL OSCILLATION; INTERANNUAL VARIABILITY; EARLY WINTER; CIRCULATION; NORTHERN; PROPAGATION AB Observations of the Southern Hemispheric winter conditions indicate that the major warming of September 2002 resulted from a combination of stationary wave-1 and traveling wave-2 forcing events and suggest that wave and mean-flow anomalies present earlier that winter may have also played a role. Quantities such as the location of the zero wind line, the strength and wave geometry of the vortex, and the horizontal and vertical wave fluxes all differed significantly from climatological values throughout much of the 2002 winter. An analysis of the anomalous features suggests the hypothesis that the persistence of a traveling wave 2 may have increased the likelihood of the combination with stationary wave 4, leading to the observed unprecedented increase in upward Eliassen-Palm flux preceding the warming. The anomalous conditions of the 2002 winter began as early as mid-May of that year and consisted of a large burst of wave flux into the stratosphere and a strong deceleration of the vortex during its early stage of development. The low-latitude easterly anomaly that resulted from this (unprecedented) event appears to have enhanced the poleward focusing of wave activity in the mid- and upper stratosphere during the rest of the winter. The altered wave geometry of the 2002 vortex allowed internal reflection of traveling wave 2, which helps to explain its unusual persistence during the rest of the winter. C1 Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY USA. Columbia Univ, Dept Appl Math, Palisades, NY USA. NASA, Goddard Inst Space Studies, Greenbelt, MD USA. Columbia Univ, Ctr Climate Syst Res, New York, NY USA. RP Harnik, N (reprint author), Tel Aviv Univ, Dept Geophys & Planetary Sci, IL-69978 Tel Aviv, Israel. EM harnik@post.tau.ac.il RI Perlwitz, Judith/B-7201-2008 OI Perlwitz, Judith/0000-0003-4061-2442 NR 21 TC 12 Z9 13 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR PY 2005 VL 62 IS 3 BP 640 EP 650 DI 10.1175/JAS-3327.1 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 911NU UT WOS:000228012100008 ER PT J AU Manney, GL Sabutis, JL Allen, DR Lahoz, WA Scaife, AA Randall, CE Pawson, S Naujokat, B Swinbank, R AF Manney, GL Sabutis, JL Allen, DR Lahoz, WA Scaife, AA Randall, CE Pawson, S Naujokat, B Swinbank, R TI Simulations of dynamics and transport during the September 2002 Antarctic major warming SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID INTERANNUAL VARIABILITY; NORTHERN-HEMISPHERE; WINTER STRATOSPHERE; PLANETARY-WAVES; OZONE HOLE; FEBRUARY 1979; POLAR VORTEX; MODEL; PROPAGATION; CIRCULATION AB A mechanistic model simulation initialized on 14 September 2002, forced by 100-hPa geopotential heights from Met Office analyses, reproduced the dynamical features of the 2002 Antarctic major warming. The vortex split on similar to 25 September; recovery after the warming, westward and equatorward tilting vortices, and strong baroclinic zones in temperature associated with a dipole pattern of upward and downward vertical velocities were all captured in the simulation. Model results and analyses show a pattern of strong upward wave propagation throughout the warming, with zonal wind deceleration throughout the stratosphere at high latitudes before the vortex split, continuing in the middle and upper stratosphere and spreading to lower latitudes after the split. Three-dimensional Eliassen-Palm fluxes show the largest upward and poleward wave propagation in the 0 degrees-90 degrees E sector prior to the vortex split (coincident with the location of strongest cyclogenesis at the model's lower boundary), with an additional region of strong upward propagation developing near 180 degrees-270 degrees E. These characteristics are similar to those of Arctic wave-2 major warmings, except that during this warming, the vortex did not split below similar to 600 K. The effects of poleward transport and mixing dominate modeled trace gas evolution through most of the mid- to high-latitude stratosphere, with a core region in the lower-stratospheric vortex where enhanced descent dominates and the vortex remains isolated. Strongly tilted vortices led to low-latitude air overlying vortex air, resulting in highly unusual trace gas profiles. Simulations driven with several meteorological datasets reproduced the major warming, but in others, stronger latitudinal gradients at high latitudes at the model boundary resulted in simulations without a complete vortex split in the midstratosphere. Numerous tests indicate very high sensitivity to the boundary fields, especially the wave-2 amplitude. Major warmings occurred for initial fields with stronger winds and larger vortices, but not smaller vortices, consistent with the initiation of wind deceleration by upward-propagating waves near the poleward edge of the region where wave 2 can propagate above the jet core. Thus, given the observed 100-hPa boundary forcing, stratospheric preconditioning is not needed to reproduce a major warming similar to that observed. The anomalously strong forcing in the lower stratosphere can be viewed as the primary direct cause of the major warming. C1 New Mexico Highlands Univ, Dept Nat Sci, Las Vegas, NM 87701 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. New Mexico Highlands Univ, Sch Educ, Las Vegas, NM 87701 USA. New Mexico Highlands Univ, Dept Math Sci, Las Vegas, NM 87701 USA. USN, Res Lab, Remote Sensing Div, Washington, DC 20375 USA. Univ Reading, Data Asimilat Res Ctr, Dept Meteorol, Reading, Berks, England. Meteorol Off, Exeter, Devon, England. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Free Univ Berlin, Inst Meteorol, D-1000 Berlin, Germany. RP New Mexico Highlands Univ, Dept Nat Sci, Las Vegas, NM 87701 USA. EM manney@mls.jpl.nasa.gov RI Pawson, Steven/I-1865-2014; Randall, Cora/L-8760-2014 OI Pawson, Steven/0000-0003-0200-717X; Randall, Cora/0000-0002-4313-4397 NR 55 TC 46 Z9 48 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR PY 2005 VL 62 IS 3 BP 690 EP 707 DI 10.1175/JAS-3313.1 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 911NU UT WOS:000228012100011 ER PT J AU Stolarski, RS McPeters, RD Newman, PA AF Stolarski, RS McPeters, RD Newman, PA TI The ozone hole of 2002 as measured by TOMS SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID SPRINGTIME ANTARCTIC OZONE; SOUTH-POLE AB Since its discovery in 1985, the ozone hole has been regularly mapped using the data from Total Ozone Mapping Spectrometer (TOMS) instruments on several satellites. The current TOMS, on the Earth Probe satellite, has been taking measurements since 1996. The ozone hole first appeared during the 1980s. Since 1990, the hole has consistently developed during each Antarctic spring over a broad area with the minimum total ozone value reaching about 100 Dobson units (DU; 1 DU = 2.69 X 10(16) Molecules cm(-2)) in late September or eariv October. The year 2002 was markedly different from the past 12 years. A series of strong wave events weakened the South Polar vortex. In late September, a major stratospheric warming took place, reversing the direction of the polar flow and the latitudinal temperature gradient. This warming resulted in a division of the ozone hole into two pieces, one that migrated to lower latitudes and disappeared and one that reformed over the Pole in a weakened form. The development of this year's unusual ozone hole is shown here and is contrasted to a climatology of the years since 1990. Minimum daily values of total ozone barely reached 150 DU in contrast to values nearer to 100. The area of the ozone hole briefly reached 18 X 10(6) km(2), then dropped rapidly to only 2 X 10(6) km(2). and finally recovered to about 8 X 10(6) km(2) before disappearing in early November. The positive anomaly compared with the last 12 yr near the Pole was accompanied by a smaller negative anomaly north of 45 degrees S. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Stolarski, RS (reprint author), NASA, Goddard Space Flight Ctr, Code 916, Greenbelt, MD 20771 USA. EM stolar@polska.gsfc.nasa.gov RI Newman, Paul/D-6208-2012; Stolarski, Richard/B-8499-2013; McPeters, Richard/G-4955-2013 OI Newman, Paul/0000-0003-1139-2508; Stolarski, Richard/0000-0001-8722-4012; McPeters, Richard/0000-0002-8926-8462 NR 14 TC 19 Z9 22 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR PY 2005 VL 62 IS 3 BP 716 EP 720 DI 10.1175/JAS-3338.1 PG 5 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 911NU UT WOS:000228012100013 ER PT J AU Orsolini, YJ Randall, CE Manney, GL Allen, DR AF Orsolini, YJ Randall, CE Manney, GL Allen, DR TI An observational study of the final breakdown of the Southern Hemisphere stratospheric vortex in 2002 SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID POLAR VORTEX; LATE WINTER; TRANSPORT; OZONE; EVOLUTION; VORTICES; CLIMATOLOGY; DYNAMICS; FALL; WAVE AB The 2002 Southern Hemisphere final warming occurred early, following an unusually active winter and the first recorded major warming in the Antarctic. The breakdown of the stratospheric polar vortex in October and November 2002 is examined using new satellite observations from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument aboard the European Space Agency (ESA) Environment Satellite (ENVISA7-) and meteorological analyses, both high-resolution fields from the European Centre for Medium-Rangc Weather Forecasts and the coarser Met Office analyses. The results derived from MIPAS observations are compared to measurements and inferences from well-validated solar occultation satellite instruments [Halogen Occultation Experiment (HALOE), Polar Ozone and Aerosol Measurement lit (POAM III), and Stratospheric Aerosol and Gas Experiments II and III (SAGE II and III)] and to finescale tracer fields reconstructed by transporting trace gases based oil MIPAS or climatological data using a reverse-trajectory method. These comparisons confirm the features in the MIPAS data and the interpretation of the evolution of the flow during the vortex decay revealed by those features. Mapped ozone and water vapor from MIPAS and the analyzed isentropic potential vorticity vividly display the vortex breakdown, which occurred earlier than usual. A large tongue of vortex air was pulled out westward and coiled up in an anticyclone, while the vortex core remnant shrank and drifted eastward and equatorward over the South Atlantic. By roughly mid-November, the vortex remnant at 10 mb had shrunk below scales resolved by the satellite observations, while a vortex core remained in the lower stratosphere. C1 Norwegian Inst Air Res, N-2027 Kjeller, Norway. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. New Mexico Highlands Univ, Dept Nat Sci, Las Vegas, NV USA. USN, Res Lab, Washington, DC 20375 USA. RP Norwegian Inst Air Res, Instituttveien 18, N-2027 Kjeller, Norway. EM orsolini@nilu.no RI Randall, Cora/L-8760-2014 OI Randall, Cora/0000-0002-4313-4397 NR 36 TC 18 Z9 18 U1 1 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR PY 2005 VL 62 IS 3 BP 735 EP 747 DI 10.1175/JAS-3315.1 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 911NU UT WOS:000228012100015 ER PT J AU Randall, CE Manney, GL Allen, DR Bevilacqua, RM Hornstein, J Trepte, C Lahoz, W Ajtic, JV Bodeker, G AF Randall, CE Manney, GL Allen, DR Bevilacqua, RM Hornstein, J Trepte, C Lahoz, W Ajtic, JV Bodeker, G TI Reconstruction and simulation of stratospheric ozone distributions during the 2002 austral winter SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID POLAR VORTEX; POAM-III; EFFECTIVE DIFFUSIVITY; ANTARCTIC WINTER; TRANSPORT; VALIDATION; ASSIMILATION; EVOLUTION; LATITUDE; MODEL AB Satellite-based solar occultation measurements during the 2002 austral winter have been used to reconstruct global, three-dimensional ozone distributions. The reconstruction method uses correlations between potential vorticity and ozone to derive "proxy" distributions from the geographically limited occultation observations. Ozone profiles from the Halogen Occultation Experiment (HALOE), the Polar Ozone and Aerosol Measurement III (POAM 111), and the Stratospheric Aerosol and Gas Experiment 11 and III (SAGE 11 and 111) are incorporated into the analysis. Because this is one of the first uses of SAGE III data in a scientific analysis, preliminary validation results are shown. The reconstruction method is described, with particular emphasis on uncertainties caused by noisy and/or multivalued correlations. The evolution of the solar occultation data and proxy ozone fields throughout the winter is described, and differences with respect to previous winters are characterized. The results support the idea that dynamical forcing early in the 2002 winter influenced the morphology of the stratosphere in a significant and unusual manner, possibly setting the stage for the unprecedented major stratospheric warming in late September. The proxy is compared with ozone from mechanistic, primitive equation model simulations of passive ozone tracer fields during the time of the warming. In regions where chemistry is negligible compared to transport, the model and proxy ozone fields agree well. The agreement between, and changes in, the large-scale ozone fields in the modal and proxy indicate that transport processes, particularly enhanced poleward transport and mixing, are the primary cause of ozone changes through most of the stratosphere during this unprecedented event. The analysis culminates with the calculation of globally distributed column ozone during the major warming, showing quantitatively how transport of low-latitude air to the polar region in the middle stratosphere led to the diminished ozone hole in 2002. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. USN, Res Lab, Washington, DC USA. Langley Res Ctr, Hampton, VA USA. Data Assimilat Res Ctr, Reading, Berks, England. Natl Inst Water & Atmospher Res, Central Otago, New Zealand. Univ Canterbury, Dept Phys & Astron, Christchurch 1, New Zealand. RP Univ Colorado, Atmospher & Space Phys Lab, UCB 392, Boulder, CO 80309 USA. EM cora.randall@lasp.colorado.edu RI Bodeker, Greg/A-8870-2008; Randall, Cora/L-8760-2014 OI Bodeker, Greg/0000-0003-1094-5852; Randall, Cora/0000-0002-4313-4397 NR 31 TC 22 Z9 22 U1 0 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR PY 2005 VL 62 IS 3 BP 748 EP 764 DI 10.1175/JAS-3336.1 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 911NU UT WOS:000228012100016 ER PT J AU Kondragunta, S Flynn, LE Neuendorffer, A Miller, AJ Long, C Nagatani, R Zhou, S Beck, T Beach, E McPeters, R Stolarski, R Bhartia, PK DeLand, MT Huang, LK AF Kondragunta, S Flynn, LE Neuendorffer, A Miller, AJ Long, C Nagatani, R Zhou, S Beck, T Beach, E McPeters, R Stolarski, R Bhartia, PK DeLand, MT Huang, LK TI Vertical structure of the anomalous 2002 Antarctic ozone hole SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID DATA SET; WINTER; TOMS; METEOROLOGY; MORPHOLOGY AB Ozone estimates from observations by the NOAA-16 Solar Backscattered Ultraviolet (SBUV/2) instrument and Television Infrared Observation Satellite (TIROS-N) Operational Vertical Sounder (TOVS) are used to describe the vertical structure of ozone in the anomalous 2002 polar vortex. The SBUV/2 total ozone maps show that the ozone hole was pushed off the Pole and split into two halves due to a split in the midstratospheric polar vortex in late September. The vortex split and the associated transport of high ozone from midlatitudes to the polar region reduced the ozone hole area from IS X 106 km(2) on 20 September to 3 x 10(6) km(2) on 27 September 2002. A 23-yr time series of SBUV/2 daily zonal mean total ozone amounts between 70 degrees and 80 degrees S shows record high values [385 Dobson units (DU)] during the late-September 2002 warming event. The transport and descent of high ozone from low latitudes to high latitudes between 60 and 15 mb contributed to the unusual increase in total column ozone and a small ozone hole estimated using the standard criterion (area with total ozone < 220 DU). In contrast, TOVS observations show an ozone-depleted region between 0 and 24 km, indicating that ozone destruction was present in the elongated but unsplit vortex in the lower stratosphere. During the warming event, the low-ozone regions in the middle and upper stratosphere were not vertically aligned with the low-ozone regions in the upper troposphere and lower stratosphere. This offset in the vertical distribution of ozone resulted in higher total column ozone masking the ozone depletion in the lower stratosphere and resulting in a smaller ozone hole size estimate from satellite total ozone data. C1 NOAA, NESDIS, Ctr Satellite Applicat & Res, Camp Springs, MD 20746 USA. NOAA, NWS, Climate Predict Ctr, Camp Springs, MD 20746 USA. RS Informat Syst Inc, Mclean, VA USA. DSTI, Rockville, MD USA. SSAI, Greenbelt, MD USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP NOAA, NESDIS, Ctr Satellite Applicat & Res, 5200 Auth Rd, Camp Springs, MD 20746 USA. EM Shoblia.Kondragunta@noaa.gov RI Flynn, Lawrence/B-6321-2009; Kondragunta, Shobha/F-5601-2010; Beach, Eric/F-5576-2010; Stolarski, Richard/B-8499-2013; McPeters, Richard/G-4955-2013; Bhartia, Pawan/A-4209-2016 OI Flynn, Lawrence/0000-0001-6856-2614; Kondragunta, Shobha/0000-0001-8593-8046; Stolarski, Richard/0000-0001-8722-4012; McPeters, Richard/0000-0002-8926-8462; Bhartia, Pawan/0000-0001-8307-9137 NR 24 TC 8 Z9 9 U1 1 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD MAR PY 2005 VL 62 IS 3 BP 801 EP 811 DI 10.1175/JAS-3324.1 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 911NU UT WOS:000228012100020 ER PT J AU Chen, CW Hensley, S AF Chen, CW Hensley, S TI Amplitude-based height-reconstruction techniques for synthetic aperture ladar systems SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article AB We examine the performance of amplitude-based height-estimation techniques for use with airborne synthetic aperture ladar (SAL) sensors in generating three-dimensional reconstructions of ground targets. Such techniques lend themselves to implementation more readily than phase-based techniques and are also more tolerant to phase instabilities that might be associated with SAL systems. For pairwise amplitude-comparison monopulse processing, we present analyses of the expected height sensitivity and bias of SAL systems in terms of the system parameters. We verify this analysis with simulations, and we also provide an overview of other SAL phenomena that affect height-estimation accuracy. We then propose an array-based joint-processing approach that can be applied instead of pairwise monopulse processing. We show that the joint-processing approach represents the maximum-likelihood estimator for obtaining the target height, and we demonstrate that the proposed approach significantly reduces bias-induced errors. (C) 2005 Optical Society of America. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Chen, CW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM curtis.chen@jpl.nasa.gov NR 7 TC 5 Z9 5 U1 0 U2 1 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1084-7529 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD MAR PY 2005 VL 22 IS 3 BP 529 EP 538 DI 10.1364/JOSAA.22.000529 PG 10 WC Optics SC Optics GA 901FX UT WOS:000227269500015 PM 15770991 ER PT J AU Ivosevic, M Knight, R Kalidindi, SR Palmese, GR Sutter, JK AF Ivosevic, M Knight, R Kalidindi, SR Palmese, GR Sutter, JK TI Adhesive/cohesive properties of thermally sprayed functionally graded coatings for polymer matrix composites SO JOURNAL OF THERMAL SPRAY TECHNOLOGY LA English DT Article; Proceedings Paper CT International Thermal Spray Conference (ITSC 2003) CY MAY 05-08, 2003 CL Orlando, FL DE adhesion/cohesion; functionally graded coatings; thermally sprayed polymers AB High-velocity oxyfuel (HVOF) sprayed polyimide/WC-Co functionally graded (FGM) coatings with flame-sprayed WC-Co topcoats have been investigated as solutions to improve the solid-particle erosion and oxidation resistance of polymer matrix composites (PMCs) in the gas flow path of advanced turbine engines. Porosity, coating thickness, and volume fraction of the WC-Co phase retained in the graded coating architecture were determined using standard metallographic techniques and computer image analysis. The adhesive bond strength of three different types of coatings was evaluated according to ASTM D 4541. Adhesive/ cohesive strengths of the FGM coating were measured and compared with those of pure polyimide and polyimide/WC-Co composite coatings and also related to the tensile strength of the uncoated PMC substrate perpendicular to the thickness. The FGM coatings exhibited lower adhesive bond strengths (similar to 6.2 MPa) than pure polyimide coatings (similar to 8.4 MPa), and in all cases these values were lower than the tensile strength (similar to 17.6 MPa) of the reference uncoated PMC substrate. The nature and locus of the failures were characterized according to the percent adhesive and/or cohesive failure, and the interfaces tested and layers involved were analyzed by scanning electron microscopy. C1 Drexel Univ, Philadelphia, PA 19104 USA. NASA, Glenn Res Ctr, Cleveland, OH USA. RP Ivosevic, M (reprint author), Drexel Univ, Philadelphia, PA 19104 USA. EM knightr@coe.drexel.edu RI Kalidindi, Surya/A-1024-2007; OI Kalidindi, Surya/0000-0001-6909-7507 NR 10 TC 28 Z9 28 U1 0 U2 8 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 USA SN 1059-9630 J9 J THERM SPRAY TECHN JI J. Therm. Spray Technol. PD MAR PY 2005 VL 14 IS 1 BP 45 EP 51 DI 10.1361/10599630522765 PG 7 WC Materials Science, Coatings & Films SC Materials Science GA 905OC UT WOS:000227577200007 ER PT J AU Tumakha, S Goss, SH Brillson, LJ Okojie, RS AF Tumakha, S Goss, SH Brillson, LJ Okojie, RS TI Electronic defect states at annealed metal/4H-SiC interfaces SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B LA English DT Article ID STACKING-FAULTS; CONTACTS; TRANSFORMATION; RESONANCE; VACANCY; 4H AB We have used low energy electron-excited nanoscale * luminescence spectroscopy (LEEN) to study the formation of electronic surface states at metal/4H-SiC contacts. These junctions were formed using both low and high reactivity metals to study how the nature of interface chemical bonding affects the interface state formation. We observe evidence for the formation and removal of localized states at energies that have been associated with morphological SiC defects. Metals such as Au and Ag with no strong chemical reactivity exhibited the most pronounced changes. Conversely, chemically-reactive metals such as Ti and Ni exhibited only minor changes and only with high temperature annealing. These observations suggest that native-defects rather then metal-specific chemical bonding dominate the interface electronic features. (c) 2005 American Vacuum Society. C1 Ohio State Univ, Dept Elect Engn & Comp Sci, Dreese Lab 205, Columbus, OH 43210 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Tumakha, S (reprint author), Ohio State Univ, Dept Elect Engn & Comp Sci, Dreese Lab 205, Columbus, OH 43210 USA. EM tumakha.1@osu.edu NR 23 TC 4 Z9 4 U1 1 U2 2 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 1071-1023 J9 J VAC SCI TECHNOL B JI J. Vac. Sci. Technol. B PD MAR-APR PY 2005 VL 23 IS 2 BP 594 EP 598 DI 10.1116/1.1884124 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 921TT UT WOS:000228788600043 ER PT J AU Desmidt, HA Wang, KW Smith, EC Provenza, AJ AF Desmidt, HA Wang, KW Smith, EC Provenza, AJ TI On the robust stability of segmented driveshafts with active magnetic bearing control SO JOURNAL OF VIBRATION AND CONTROL LA English DT Article DE supercritical driveline; magnetic bearings; periodic systems; robust control ID UNIVERSAL JOINT; SYSTEM DRIVEN; VIBRATION; MOTION AB Many researchers and engineers have employed active control techniques, such as active magnetic bearings (AMBs), to suppress imbalance vibration in various subcritical and supercritical speed rotor-dynamic applications. One issue that has not yet been addressed in previous AMB driveline control studies is the effect of non-constant velocity (NCV) flexible couplings, such as U-joint or disk-type couplings, present in many segmented drivelines. The NCV effects introduce periodic parametric and forcing terms into the equations of motion that are functions of shaft speed, driveline misalignment, and load-torque, resulting in a linear periodically time-varying system. Previous research has found that both internal damping and NCV terms greatly impact stability; thus, they must be accounted for in the control law design in order to ensure closed-loop stability of any AMB-NCV-driveline system. In this paper, numerical Floquet theory is used to explore the closed-loop stability of a flexible segmented NCV-driveline supported by AMBs with a proportional-derivative (PD) type controller. To ensure robust stability with respect to internal damping and NCV effects, the robust P and D gains and AMB locations are selected based on maximizing a stability index over a range of shaft speeds, driveline misalignments, and load-torques. It is found that maximum robustness occurs within a finite range of P and D gains for several different AMB locations. Finally, the range of robustly stabilizing P gains versus the shaft speed is examined for several misalignment and load-torque bounds. C1 Penn State Univ, Dept Mech Engn, University Pk, PA 16802 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Desmidt, HA (reprint author), Penn State Univ, Dept Mech Engn, 157 Hammond Bldg, University Pk, PA 16802 USA. EM kwwang@psu.edu NR 16 TC 4 Z9 4 U1 1 U2 3 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1077-5463 J9 J VIB CONTROL JI J. Vib. Control PD MAR PY 2005 VL 11 IS 3 BP 317 EP 329 DI 10.1177/1077546305051200 PG 13 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 910WT UT WOS:000227963600001 ER PT J AU Lanzafame, RJ Stadler, I Whittaker, M Whelan, HT AF Lanzafame, RJ Stadler, I Whittaker, M Whelan, HT TI NASA led photoradiation influences TNF alpha and TGF beta production in a murine wound model SO LASERS IN SURGERY AND MEDICINE LA English DT Meeting Abstract CT 25th Annual Meeting of the American-Society-for-Laser-Medicine-and-Surgery CY MAR 30-APR 03, 2005 CL Buena Vista, FL SP Amer Soc Laser Med & Surg C1 Rochester Gen Hosp, Ctr Laser, Rochester, NY 14621 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WILEY-LISS PI HOBOKEN PA DIV JOHN WILEY & SONS INC, 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0196-8092 J9 LASER SURG MED JI Lasers Surg. Med. PD MAR PY 2005 SU 17 MA 188 BP 57 EP 57 PG 1 WC Dermatology; Surgery SC Dermatology; Surgery GA 912GQ UT WOS:000228066000176 ER PT J AU Cronin, TM Dowsett, HJ Dwyer, GS Baker, PA Chandler, MA AF Cronin, TM Dowsett, HJ Dwyer, GS Baker, PA Chandler, MA TI Mid-pliocene deep-sea bottom-water temperatures based on ostracode Mg/Ca ratios SO MARINE MICROPALEONTOLOGY LA English DT Article DE paleoceanography; Pliocene; ostracode shell chemistry; ocean temperature; Mg/Ca ID GENERAL-CIRCULATION MODEL; NORTH-ATLANTIC OCEAN; SEAWATER CHEMISTRY; TRACE-ELEMENT; LATE NEOGENE; THERMOHALINE CIRCULATION; PALEOTEMPERATURE CHANGES; SURFACE TEMPERATURES; CARBONATE MINERALOGY; NONMARINE OSTRACODS AB We studied magnesium: calcium (Mg/Ca) ratios in shells of the deep-sea ostracode genus Krithe from a short interval in the middle Pliocene between 3.29 and 2.97 Ma using deep-sea drilling sites in the North and South Atlantic in order to estimate bottom water temperatures (BWT) during a period of climatic warmth. Results from DSDP and ODP Sites 552A, 610A, 607, 658A, 659A, 661A and 704 for the period Ma reveal both depth and latitudinal gradients of mean Mg/Ca values. Shallower sites (552A, 610A and 607) have higher mean Mg/Ca ratios (10.3, 9.7, 10.1 mmol/mol) than deeper sites (661A, 6.3 mmol/mol), and high latitude North Atlantic sites (552A, 610 and 607) have higher Mg/Ca ratios than low latitude (658A: 9.8 mmol/mol, 659A: 7.7 mmol/mol, 661A: 6.3 mmol/mol) and Southern Ocean (704: 8.0 mmol/mol) sites. Converting Mg/Ca ratios into estimated temperatures using the calibration of Dwyer et al. (1995) [Dwyer, G.S., Cronin, T.M., Baker, P.A., Raymo, M.E., Buzas, J.S., Correge, T., 1995. North Atlantic deepwater temperature change during late Pliocene and late Quaternary climatic cycles. Science 270, 1347-1351] suggests that mean middle Pliocene bottom water temperatures at the study sites in the deep Atlantic were about the same as modem temperatures. However, brief pulses of elevated BWT occurred several times between 3.29 and 2.97 Ma in both the North and South Atlantic Ocean suggesting short-term changes in deep ocean circulation. Published by Elsevier B.V. C1 US Geol Survey, Reston, VA 20192 USA. Duke Univ, Nicholas Sch Environm & Earth Sci, Div Earth & Ocean Sci, Durham, NC 27708 USA. Columbia Univ, Goddard Inst Space Studies, New York, NY 10025 USA. RP Cronin, TM (reprint author), US Geol Survey, 926A, Reston, VA 20192 USA. EM tcronin@usgs.gov OI Dowsett, Harry/0000-0003-1983-7524 NR 93 TC 28 Z9 28 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 EI 1872-6186 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD MAR PY 2005 VL 54 IS 3-4 BP 249 EP 261 DI 10.1016/j.marmicro.2004.12.003 PG 13 WC Paleontology SC Paleontology GA 904WY UT WOS:000227530500006 ER PT J AU Shrestha, S Kharkovsky, S Zoughi, R Hepburn, E AF Shrestha, S Kharkovsky, S Zoughi, R Hepburn, E TI Microwave and millimeter wave nondestructive testing of the space shuttle external tank insulating foam SO MATERIALS EVALUATION LA English DT Article DE microwaves; millimeter waves; near field; insulating foam; disbond; void ID COMPOSITES; DELAMINATION; THICKNESS; DISBOND AB The space shuttle Columbia's catastrophic failure has been attributed to a piece of external fuel tank insulating foam (spray oil foam insulation) striking the leading edge of the left wing of the orbiter causing significant damage to some of the protecting heat tiles. The accident emphasizes the growing need to develop effective, robust and life cycle oriented methods of nondestructive testing (NDT) of complex conductor backed insulating foam and protective acreage heat tiles used in the space shuttle fleet and in future multilaunch space vehicles. The insulating spray oil foam is constructed from closed cell foam. In the microwave regime, this foam is in the family of low permittivity and low loss dielectric materials. Near field microwave and millimeter wave NDT techniques were one of the techniques chosen for testing this material. (Microwaves are electromagnetic waves with frequencies between 0.3 and 300 GHz. Those in the frequency range above about 30 GHz are generally referred to as millimeter waves because their wavelengths in free space are conveniently measured in millimeters.) To this end, several flat and thick spray on foam insulation panels, two structurally complex panels similar to the external fuel tank and a blind panel were used in this investigation. Several discontinuities such as voids and disbonds were embedded in these panels at various locations. The location and properties of the embedded discontinuities in the blind panel were not disclosed to the investigating team prior to the investigation. Three frequency bands were used in this investigation, covering a frequency range of 8 to 75 GHz. Moreover, the influence of signal polarization was also investigated. Overall, the results of this investigation were very promising for detecting the presence of discontinuities in different panels covered with relatively thick insulating spray on foam. Different types of discontinuities were detected in foam up to 229 nun (9 in.) thick. Many of the discontinuities in the more complex panels were also detected. Mien investigating the blind panel, no false positives were detected. Discontinuities in between and underneath bolt heads were not easily detected. This paper presents the results of this investigation along with a discussion of the capabilities of the technique used. C1 Univ Missouri, Dept Elect & Comp Engn, Appl Microwave Nondestruct Testing Lab, Rolla, MO 65409 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Shrestha, S (reprint author), Univ Missouri, Dept Elect & Comp Engn, Appl Microwave Nondestruct Testing Lab, Rolla, MO 65409 USA. EM zoughir@umr.edu NR 15 TC 12 Z9 14 U1 1 U2 4 PU AMER SOC NONDESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD MAR PY 2005 VL 63 IS 3 BP 339 EP 344 PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA 904LG UT WOS:000227498900010 ER PT J AU Wernet, MP AF Wernet, MP TI Symmetric phase only filtering: a new paradigm for DPIV data processing SO MEASUREMENT SCIENCE AND TECHNOLOGY LA English DT Article DE particle image velocity; data processing; optical correlation ID PARTICLE IMAGE VELOCIMETRY; TIME-DELAY; PIV AB The standard approach in digital particle image velocimetry (DPIV) data processing is to use fast Fourier transforms to obtain the cross-correlation of two single exposure subregions, where the location of the cross-correlation peak is representative of the most probable particle displacement across the subregion. This standard DPIV processing technique is analogous to matched spatial filtering, a technique commonly used in optical correlators to perform the cross-correlation operation. Phase only filtering is a well-known variation of matched spatial filtering, which when used to process DPIV image data yields correlation peaks which are narrower and up to an order of magnitude larger than those obtained using traditional DPIV processing. In addition to possessing desirable correlation plane features, phase only filters also provide superior performance in the presence of dc noise in the correlation subregion. When DPIV image subregions contaminated with surface flare light or high background noise levels are processed using phase only filters, the correlation peak pertaining only to the particle displacement is readily detected above any signal stemming from the dc objects. Tedious image masking or background image subtraction is not required. Both theoretical and experimental analyses of the signal-to-noise ratio performance of the filter functions are presented. In addition, a new symmetric phase only filtering (SPOF) technique, which is a variation on the traditional phase only filtering technique, is described and demonstrated. The SPOF technique exceeds the performance of the traditionally accepted phase only filtering techniques and is easily implemented in standard DPIV FFT-based correlation processing with no significant computational performance penalty. The SPOF-based optical correlation processing approach is presented as a new paradigm for more robust cross-correlation processing of low signal-to-noise ratio DPIV image data. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 17 TC 38 Z9 38 U1 1 U2 5 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 MAR PY 2005 VL 16 IS 3 BP 601 EP 618 DI 10.1088/0957-0233/16/3/001 PG 18 WC Engineering, Multidisciplinary; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 908DC UT WOS:000227766500002 ER PT J AU Penko, PF AF Penko, PF TI Old wheels SO MECHANICAL ENGINEERING LA English DT Letter C1 NASA, Glenn Res Ctr, Brookpark, OH USA. RP Penko, PF (reprint author), NASA, Glenn Res Ctr, Brookpark, OH USA. NR 0 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 0025-6501 J9 MECH ENG JI Mech. Eng. PD MAR PY 2005 VL 127 IS 3 BP 6 EP 6 PG 1 WC Engineering, Mechanical SC Engineering GA 902EQ UT WOS:000227337400004 ER PT J AU Noble, SK Keller, LP Pieters, CM AF Noble, SK Keller, LP Pieters, CM TI Evidence of space weathering in regolith breccias I: Lunar regolith breccias SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID INTERPLANETARY DUST PARTICLES; FINEST FRACTION; VAPOR DEPOSITS; HELIUM; IRRADIATION; METEORITES; ASTEROIDS; OLIVINE; SAMPLES; GRAINS AB We have analyzed a suite of lunar regolith breccias in order to assess how well space weathering products can be preserved through the lithification process and therefore whether or not it is appropriate to search for space weathering products in asteroidal regolith breccia meteorites. It was found that space weathering products, vapor/sputter deposited nanophase-iron-bearing rims in particular, are easily identified in even heavily shocked/compacted lunar regolith breccias. Such rims, if created on asteroids, should thus be preserved in asteroidal regolith breccia meteorites. Two additional rim types, glass rims and vesicular rims, identified in regolith breccias, are also described. These rims are common in lunar regolith breccias but rare to absent in lunar soils, which suggests that they are created in the breccia-forming process itself. While not "space weathering products" in the strictest sense, these additional rims give us insight into the regolith breccia formation process. The presence or absence of glass and/or vesicular rims in asteroidal regolith breccias will likewise tell us about environmental conditions on the surface of the asteroid body on which the breccia was created. C1 Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Noble, SK (reprint author), Brown Univ, Dept Geol Sci, Box 1846, Providence, RI 02912 USA. EM noble@porter.geo.brown.edu RI Noble, Sarah/D-7614-2012 NR 34 TC 23 Z9 25 U1 1 U2 6 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD MAR PY 2005 VL 40 IS 3 BP 397 EP 408 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 937BN UT WOS:000229899700005 ER PT J AU Suehle, JS Zhu, B Chen, Y Bernstein, JB AF Suehle, JS Zhu, B Chen, Y Bernstein, JB TI Detailed study and projection of hard breakdown evolution in ultra-thin gate oxides SO MICROELECTRONICS RELIABILITY LA English DT Article AB The mechanism responsible for post-soft breakdown leakage current increase in ultra-thin oxides depends on the nature of the conducting filament formed at the instant of dielectric breakdown. The conductance of the filament formed during soft breakdown has been observed to be either stable until hard breakdown occurs or to increase continually with time. The acceleration factors for predicting hard breakdown are different in each case. Recent experimental results suggest that the "hardness" of the first breakdown influences the type of conducting filament formed during the soft breakdown event the time in which hard breakdown subsequently occurs. Electron current-induced defect formation appears to be the driving force for the eventual hard breakdown event. (C) 2004 Elsevier Ltd. All rights reserved. C1 NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Mech Engn, College Pk, MD 20742 USA. Jet Prop Lab, Elect Parts Engn Off, Pasadena, CA 91109 USA. RP Suehle, JS (reprint author), NIST, Div Semicond Elect, Gaithersburg, MD 20899 USA. EM john.suehle@nist.gov NR 19 TC 11 Z9 11 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0026-2714 J9 MICROELECTRON RELIAB JI Microelectron. Reliab. PD MAR-APR PY 2005 VL 45 IS 3-4 BP 419 EP 426 DI 10.1016/j.microrel.2004.10.018 PG 8 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Physics, Applied SC Engineering; Science & Technology - Other Topics; Physics GA 898DJ UT WOS:000227056000002 ER PT J AU Thoroughgood, TD Dhillon, VS Steeghs, D Watson, CA Buckley, DAH Littlefair, SP Smith, DA Still, M van der Heyden, KJ Warner, B AF Thoroughgood, TD Dhillon, VS Steeghs, D Watson, CA Buckley, DAH Littlefair, SP Smith, DA Still, M van der Heyden, KJ Warner, B TI The component masses of the cataclysmic variable V347 Puppis SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; binaries : eclipsing; binaries : spectroscopic; stars : individual : V347 Pup; novae, cataclysmic variables ID DW URSAE MAJORIS; X-RAY BINARIES; ACCRETION DISKS; DOPPLER TOMOGRAPHY; WHITE-DWARF; SPECTROSCOPIC OBSERVATIONS; ROCHE TOMOGRAPHY; SECONDARY STARS; SW SEXTANTIS; LOW STATE AB We present time-resolved spectroscopy and photometry of the double-lined eclipsing cataclysmic variable V347 Pup ( = LB 1800). There is evidence of irradiation on the inner hemisphere of the secondary star, which we correct for using a model to give a secondary-star radial velocity of K R = 198 +/- 5 km s(-1). The rotational velocity of the secondary star in V347 Pup is found to be v sin i = 131 +/- 5 km s(-1) and the system inclination is i = 84degrees.0 +/- 2degrees.3. From these parameters we obtain masses of M-1 = 0.63 +/- 0.04 M for the white dwarf primary and M-2 = 0.52 +/- 0.06 M for the M0.5V secondary star, giving a mass ratio of q = 0.83 +/- 0.05. On the basis of the component masses, and the spectral type and radius of the secondary star in V347 Pup, we find tentative evidence for an evolved companion. V347 Pup shows many of the characteristics of the SW Sex stars, exhibiting single-peaked emission lines, high-velocity S-wave components and phase-offsets in the radial velocity curve. We find spiral arms in the accretion disc of V347 Pup and measure the disc radius to be close to the maximum allowed in a pressureless disc. C1 Univ Sheffield, Dept Phys & Astron, Sheffield S3 7RH, S Yorkshire, England. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. S African Astron Observ, ZA-7935 Cape Town, South Africa. Univ Exeter, Sch Phys, Exeter EX4 4QL, Devon, England. Winchester Coll, Winchester SO23 9LX, Hants, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Cape Town, Dept Astron, ZA-7700 Rondebosch, South Africa. RP Univ Sheffield, Dept Phys & Astron, Sheffield S3 7RH, S Yorkshire, England. EM Tim.Thoroughgood@shef.ac.uk RI Steeghs, Danny/C-5468-2009; OI Steeghs, Danny/0000-0003-0771-4746; Littlefair, Stuart/0000-0001-7221-855X NR 63 TC 12 Z9 12 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0035-8711 EI 1365-2966 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAR 1 PY 2005 VL 357 IS 3 BP 881 EP 894 DI 10.1111/j.1365-2966.2004.08613.x PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 898OP UT WOS:000227086400007 ER PT J AU Cecil, DJ Goodman, SJ Boccippio, DJ Zipser, EJ Nesbitt, SW AF Cecil, DJ Goodman, SJ Boccippio, DJ Zipser, EJ Nesbitt, SW TI Three years of TRMM precipitation features. Part I: Radar, radiometric, and lightning characteristics SO MONTHLY WEATHER REVIEW LA English DT Article ID MESOSCALE CONVECTIVE SYSTEMS; MEASURING MISSION TRMM; SSM/I BRIGHTNESS TEMPERATURES; OPTICAL TRANSIENT DETECTOR; ICE-SCATTERING; TROPICAL RAINFALL; PASSIVE MICROWAVE; WSR-88D REFLECTIVITIES; HURRICANE EYEWALLS; SATELLITE AB During its first three years, the Tropical Rainfall Measuring Mission (TRMM) satellite observed nearly six million precipitation features. The population of precipitation features is sorted by lightning flash rate, minimum brightness temperature, maximum radar reflectivity, areal extent, and volumetric rainfall. For each of these characteristics, essentially describing the convective intensity or the size of the features, the population is broken into categories consisting of the top 0.001%, top 0.01%, top 0.1%, top 1%, top 2.4%, and remaining 97.6%. The set of "weakest/smallest" features composes 97.6% of the population because that fraction does not have detected lightning, with a minimum detectable flash rate of 0.7 flashes (fl) min(-1). The greatest observed flash rate is 1351 fl min(-1); the lowest brightness temperatures are 42 K (85 GHz) and 69 K (37 GHz). The largest precipitation feature covers 335000 km(2), and the greatest rainfall from an individual precipitation feature exceeds 2 X 10(12) kg h(-1) of water. There is considerable overlap between the greatest storms according to different measures of convective intensity. The largest storms are mostly independent of the most intense storms. The set of storms producing the most rainfall is a convolution of the largest and the most intense storms. This analysis is a composite of the global Tropics and subtropics. Significant variability is known to exist between locations, seasons, and meteorological regimes. Such variability will be examined in Part II. In Part I, only a crude land-ocean separation is made. The known differences in bulk lightning flash rates over land and ocean result from at least two differences in the precipitation feature population: the frequency of occurrence of intense storms and the magnitude of those intense storms that do occur. Even when restricted to storms with the same brightness temperature, same size, or same radar reflectivity aloft, the storms over water are considerably less likely to produce lightning than are comparable storms over land. C1 Univ Alabama, Ctr Earth Syst Sci, Huntsville, AL 35805 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Univ Utah, Salt Lake City, UT USA. Colorado State Univ, Ft Collins, CO 80523 USA. RP Cecil, DJ (reprint author), Univ Alabama, Ctr Earth Syst Sci, 320 Sparkman Dr, Huntsville, AL 35805 USA. EM Daniel.Cecil@msfc.nasa.gov RI Nesbitt, Stephen/I-3965-2013 OI Nesbitt, Stephen/0000-0003-0348-0452 NR 46 TC 111 Z9 115 U1 2 U2 12 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 MAR PY 2005 VL 133 IS 3 BP 543 EP 566 DI 10.1175/MWR-2876.1 PG 24 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 910SW UT WOS:000227953500004 ER PT J AU Johnson, SW Thedinga, JF AF Johnson, SW Thedinga, JF TI Fish use and size of eelgrass meadows in southeastern Alaska: A baseline for long-term assessment of biotic change SO NORTHWEST SCIENCE LA English DT Article ID PUGET SOUND; BAY; ABUNDANCE; CALIFORNIA; COMMUNITIES; SEAGRASSES; DIVERSITY; SUBSTRATE; DIEL AB Eelgrass meadows at six sites in southeastern Alaska were sampled for fish assemblages and mapped to establish a baseline of information for long-term assessment of biotic change. All sites were sampled in spring 2001, 2002, and 2003: four of the sites were also sampled in winter 2003. A total of 44 seine hauls from all sampling periods yielded 58,902 fish comprising 45 species. Fish abundance in spring differed significantly among sites but not among years. The most abundant commercially important or forage fish species captured were chum salmon, Pacific herring. pink salmon, coho salmon, and Pacific sand lance: mean size of each of these species was <= 100 mm FL. For those sites sampled seasonally in 2003, fish were significantly more abundant in spring than in winter. At each site, three different species accounted for most (>= 69%) of the total catch. Size of eelgrass meadows varied annually; maximum percent change in area ranged from -13% to +27%. Eelgrass density ranged from 336 shoots/m(2) to 1,544 shoots/m(2), and dry biomass ranged from 36 g/m(2) to 71 g/m(2). Periodic re-sampling of the eelgrass sites established in this study will allow resource managers to track long-term and large-scale changes in fish communities and habitat that may result from shoreline development or global climate change. C1 Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, Juneau, AK 99801 USA. RP Johnson, SW (reprint author), Natl Marine Fisheries Serv, Alaska Fisheries Sci Ctr, Auke Bay Lab, 11305 Glacier Highway, Juneau, AK 99801 USA. EM scott.johnson@noaa.gov NR 43 TC 8 Z9 8 U1 5 U2 16 PU WASHINGTON STATE UNIV PI PULLMAN PA PO BOX 645020, PULLMAN, WA 99164-5910 USA SN 0029-344X J9 NORTHWEST SCI JI Northwest Sci. PD SPR PY 2005 VL 79 IS 2-3 BP 141 EP 155 PG 15 WC Ecology SC Environmental Sciences & Ecology GA 995PE UT WOS:000234115500006 ER PT J AU Mathelin, L Hussaini, MY Zang, TA AF Mathelin, L Hussaini, MY Zang, TA TI Stochastic approaches to uncertainty quantification in CFD simulations SO NUMERICAL ALGORITHMS LA English DT Article DE uncertainty; stochastic; probabilistic; polynomial chaos; nozzle flow ID COMPUTATIONAL FLUID-DYNAMICS; GENERALIZED POLYNOMIAL CHAOS; FLOW; VALIDATION; VERIFICATION AB This paper discusses two stochastic approaches to computing the propagation of uncertainty in numerical simulations: polynomial chaos and stochastic collocation. Chebyshev polynomials are used in both cases for the conventional, deterministic portion of the discretization in physical space. For the stochastic parameters, polynomial chaos utilizes a Galerkin approximation based upon expansions in Hermite polynomials, whereas stochastic collocation rests upon a novel transformation between the stochastic space and an artificial space. In our present implementation of stochastic collocation, Legendre interpolating polynomials are employed. These methods are discussed in the specific context of a quasi-one-dimensional nozzle flow with uncertainty in inlet conditions and nozzle shape. It is shown that both stochastic approaches efficiently handle uncertainty propagation. Furthermore, these approaches enable computation of statistical moments of arbitrary order in a much more effective way than other usual techniques such as the Monte Carlo simulation or perturbation methods. The numerical results indicate that the stochastic collocation method is substantially more efficient than the full Galerkin, polynomial chaos method. Moreover, the stochastic collocation method extends readily to highly nonlinear equations. An important application is to the stochastic Riemann problem, which is of particular interest for spectral discontinuous Galerkin methods. C1 Florida State Univ, Tallahassee, FL 32306 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Mathelin, L (reprint author), Univ Paris 11, CNRS, LIMSI, Bat 425, F-91405 Orsay, France. EM Lionel.Mathelin@limsi.fr; myh@csit.fsu.edu; thomas.a.zang@nasa.gov NR 27 TC 114 Z9 117 U1 4 U2 25 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1017-1398 J9 NUMER ALGORITHMS JI Numer. Algorithms PD MAR PY 2005 VL 38 IS 1-3 BP 209 EP 236 DI 10.1007/s11075-004-2866-z PG 28 WC Mathematics, Applied SC Mathematics GA 897XQ UT WOS:000227040600014 ER PT J AU Georgiev, GT Butler, JJ AF Georgiev, GT Butler, JJ TI Bidirectional reflectance distribution function and directional-hemispherical reflectance of a martian regolith simulant SO OPTICAL ENGINEERING LA English DT Article DE bidirectional reflectance distribution function; hemispherical reflectance; optical scattering; reflectance spectroscopy; remote sensing ID SCATTERING; SPECTROSCOPY; PARAMETERS; PARTICLES; SURFACE; GRAINS; LIGHT AB Experimental data are presented on the bidirectional reflectance distribution function and 8-deg directional-hemispherical reflectance measurements of a Martian regolith simulant, JSC Mars-1. The scatterometer located in the National Aeronautics and Space Administration's Goddard Space Flight Center Diffuser Calibration Facility was used for the measurements reported. The data were obtained with a monochromator-based light source in the ultraviolet, visible, and near infrared spectral regions. The measurements were performed at different angles of incidence and over a range of in-plane and out-of-plane scattered geometries. The results presented are traceable to the National Institute of Standards and Technology. The hemispherical and diffuse scattering data obtained from these studies are important for current and future Mars space- and ground-based observations. (c) 2005 Society of Photo-Optical Instrumentation Engineers. C1 Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Georgiev, GT (reprint author), Sci Syst & Applicat Inc, Lanham, MD 20706 USA. EM gtg@spectral.gsfc.nasa.gov RI Butler, James/D-4188-2013 NR 23 TC 4 Z9 4 U1 0 U2 3 PU SPIE-INT SOCIETY OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98225 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD MAR PY 2005 VL 44 IS 3 AR 036202 DI 10.1117/1.1870001 PG 11 WC Optics SC Optics GA 974KK UT WOS:000232590100034 ER PT J AU Matsko, AB Strekalov, D Maleki, L AF Matsko, AB Strekalov, D Maleki, L TI Magnetometer based on the opto-electronic microwave oscillator SO OPTICS COMMUNICATIONS LA English DT Article DE optical magnetometer; electromagnetically induced transparency ID ELECTROMAGNETICALLY INDUCED TRANSPARENCY; ELECTROOPTIC MODULATOR; RUBIDIUM MAGNETOMETER; PERFORMANCE; PRINCIPLES AB We present a scheme for an all-optical self-oscillating magnetometer based on the opto-electronic oscillator stabilized with an atomic vapor cell. We demonstrate a proof of the principle with DC magnetic field measurements characterized by 2 x 10(-7) G sensitivity and 1-1000 mG dynamic range. (c) 2004 Elsevier B.V. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Matsko, AB (reprint author), CALTECH, Jet Prop Lab, MS 298-100,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Andrey.Matsko@jpl.nasa.gov RI Matsko, Andrey/A-1272-2007 NR 29 TC 11 Z9 12 U1 4 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD MAR 1 PY 2005 VL 247 IS 1-3 BP 141 EP 148 DI 10.1016/j.optcom.2004.11.047 PG 8 WC Optics SC Optics GA 905HY UT WOS:000227560400016 ER PT J AU Alexandrov, N AF Alexandrov, Natalia TI Editorial - Multidisciplinary design optimization SO OPTIMIZATION AND ENGINEERING LA English DT Editorial Material C1 NASA, Langley Res Ctr, Washington, DC 20546 USA. RP Alexandrov, N (reprint author), NASA, Langley Res Ctr, Washington, DC 20546 USA. EM N.Alexandrov@nasa.gov NR 0 TC 11 Z9 12 U1 1 U2 7 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1389-4420 J9 OPTIM ENG JI Optim. Eng. PD MAR PY 2005 VL 6 IS 1 BP 5 EP 7 DI 10.1023/B:OPTE.0000048533.43561.57 PG 3 WC Engineering, Multidisciplinary; Operations Research & Management Science; Mathematics, Interdisciplinary Applications SC Engineering; Operations Research & Management Science; Mathematics GA 899VI UT WOS:000227173200001 ER PT J AU Samareh, JA AF Samareh, Jamshid A. TI Geometry and Grid/Mesh generation issues for CFD and CSM shape optimization SO OPTIMIZATION AND ENGINEERING LA English DT Article DE shape parameterization; grid generation; mesh generation; shape optimization; grid deformation ID MESHES; DESIGN AB This paper discusses geometry and grid generation issues for an automated shape optimization using computational fluid dynamics and computational structural mechanics. Special attention is given to five major steps for shape optimization: shape parameterization, automation of model abstraction, automation of grid generation, calculation of analytical sensitivity, and robust grid deformation. C1 NASA, Langley Res Ctr, Multidisciplinary Opt Branch, Hampton, VA 23681 USA. RP Samareh, JA (reprint author), NASA, Langley Res Ctr, Multidisciplinary Opt Branch, Hampton, VA 23681 USA. EM j.a.samareh@larc.nasa.gov NR 48 TC 4 Z9 5 U1 2 U2 5 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1389-4420 J9 OPTIM ENG JI Optim. Eng. PD MAR PY 2005 VL 6 IS 1 BP 21 EP 32 DI 10.1023/B:OPTE.0000048535.08259.a8 PG 12 WC Engineering, Multidisciplinary; Operations Research & Management Science; Mathematics, Interdisciplinary Applications SC Engineering; Operations Research & Management Science; Mathematics GA 899VI UT WOS:000227173200003 ER PT J AU Martins, JRRA Alonso, JJ Reuther, JJ AF Martins, Joaquim R. R. A. Alonso, Juan J. Reuther, James J. TI A coupled-adjoint sensitivity analysis method for high-fidelity aero-structural design SO OPTIMIZATION AND ENGINEERING LA English DT Article DE sensitivity analysis; adjoint method; aero-structural design; complex-step method ID PARALLEL COMPUTERS; OPTIMIZATION; SYSTEMS; FORMULATION; COMPLEX AB This paper presents an adjoint method for sensitivity analysis that is used in an aero-structural aircraft design framework. The aero-structural analysis uses high-fidelity models of both the aerodynamics and the structures. Aero-structural sensitivities are computed using a coupled-adjoint approach that is based on previously developed single discipline sensitivity analysis. Alternative strategies for coupled sensitivity analysis are also discussed. The aircraft geometry and a structure of fixed topology are parameterized using a large number of design variables. The aero-structural sensitivities of aerodynamic and structural functions with respect to these design variables are computed and compared with results given by the complex-step derivative approximation. The coupled-adjoint procedure is shown to yield very accurate sensitivities and to be computationally efficient, making high-fidelity aero-structural design feasible for problems with thousands of design variables. C1 Univ Toronto, Inst Aerosp Studies, N York, ON M3H 5T6, Canada. Stanford Univ, Stanford, CA 94305 USA. NASA, Ames Res Ctr, Moffett Field, CA 95035 USA. RP Martins, JRRA (reprint author), Univ Toronto, Inst Aerosp Studies, N York, ON M3H 5T6, Canada. EM martins@utias.utoronto.ca; jjalonso@stanford.edu; jreuther@mail.arc.nasa.gov RI Martins, Joaquim/P-3933-2014 OI Martins, Joaquim/0000-0003-2143-1478 NR 36 TC 60 Z9 61 U1 3 U2 24 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1389-4420 J9 OPTIM ENG JI Optim. Eng. PD MAR PY 2005 VL 6 IS 1 BP 33 EP 62 DI 10.1023/B:OPTE.0000048536.47956.62 PG 30 WC Engineering, Multidisciplinary; Operations Research & Management Science; Mathematics, Interdisciplinary Applications SC Engineering; Operations Research & Management Science; Mathematics GA 899VI UT WOS:000227173200004 ER PT J AU Gumbert, CR Hou, GJW Newman, PA AF Gumbert, Clyde R. Hou, Gene J. -W. Newman, Perry A. TI High-fidelity computational optimization for 3-d flexible wings: Part I - Simultaneous aero-structural design optimization (SASDO) SO OPTIMIZATION AND ENGINEERING LA English DT Article DE optimization; multidisciplinary; SAND; design ID SENSITIVITY-ANALYSIS; AEROELASTICITY AB The formulation and implementation of a multidisciplinary optimization method called Simultaneous Aerodynamic and Structural Design Optimization (SASDO) is presented and applied to a simple, isolated, 3-D wing in inviscid flow. The method aims to reduce the computational expense incurred in performing shape and sizing optimization using existing state-of-the-art Computational Fluid Dynamics (CFD) flow analysis, FEM structural analysis and sensitivity analysis tools. Results show that the method finds the same local optimum as a conventional optimization method with as much as 50% reduction in the computational cost and without significant modifications to the analysis tools. C1 Old Dominion Univ, Norfolk, VA 23529 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Hou, GJW (reprint author), Old Dominion Univ, Norfolk, VA 23529 USA. EM clyde.r.gumbert@nasa.gov; ghou@odu.edu; perry.a.newman@nasa.gov NR 42 TC 5 Z9 5 U1 1 U2 4 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1389-4420 J9 OPTIM ENG JI Optim. Eng. PD MAR PY 2005 VL 6 IS 1 BP 117 EP 138 DI 10.1023/B:OPTE.0000048539.37526.e3 PG 22 WC Engineering, Multidisciplinary; Operations Research & Management Science; Mathematics, Interdisciplinary Applications SC Engineering; Operations Research & Management Science; Mathematics GA 899VI UT WOS:000227173200007 ER PT J AU Gumbert, CR Newman, PA Hou, GIW AF Gumbert, Clyde R. Newman, Perry A. Hou, Gene I. -W. TI High-fidelity computational optimization for 3-d flexible wings: Part II - Effect of random geometric uncertainty on design SO OPTIMIZATION AND ENGINEERING LA English DT Article DE robust design; multidisciplinary; uncertainty ID AUTOMATIC DIFFERENTIATION; SENSITIVITY DERIVATIVES; CFD AB The effect of geometric uncertainty due to statistically independent, random, normally distributed shape parameters is demonstrated in the computational design of a 3-D flexible wing. A first-order second-moment statistical approximation method is used to propagate the assumed input uncertainty through coupled Euler CFD aerodynamic/finite element structural codes for both analysis and sensitivity analysis. First-order sensitivity derivatives obtained by automatic differentiation are used in the input uncertainty propagation. These propagated uncertainties are then used to perform a robust design of a simple 3-D flexible wing at supercritical flow conditions. The effect of the random input uncertainties is shown by comparison with conventional deterministic design results. Sample results are shown for wing planform, airfoil section, and structural sizing variables. C1 Old Dominion Univ, Norfolk, VA 23529 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Hou, GIW (reprint author), Old Dominion Univ, Norfolk, VA 23529 USA. EM clyde.r.gumbert@nasa.gov; perty.a.newman@nasa.gov; ghou@odu.edu NR 33 TC 9 Z9 9 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1389-4420 J9 OPTIM ENG JI Optim. Eng. PD MAR PY 2005 VL 6 IS 1 BP 139 EP 156 DI 10.1023/B:OPTE.0000048540.61839.3c PG 18 WC Engineering, Multidisciplinary; Operations Research & Management Science; Mathematics, Interdisciplinary Applications SC Engineering; Operations Research & Management Science; Mathematics GA 899VI UT WOS:000227173200008 ER PT J AU Ross-Nazzal, J AF Ross-Nazzal, J TI Emma Smith DeVoe - Practicing pragmatic politics in the Pacific Northwest SO PACIFIC NORTHWEST QUARTERLY LA English DT Article C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Ross-Nazzal, J (reprint author), NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. NR 72 TC 0 Z9 0 U1 0 U2 0 PU UNIV WASHINGTON PI SEATTLE PA 4045 BROOKLYN AVENUE NE, SEATTLE, WA 98105 USA SN 0030-8803 J9 PAC NORTHWEST QUART JI Pac. Northwest Q. PD SPR PY 2005 VL 96 IS 2 BP 76 EP 84 PG 9 WC History SC History GA 956VB UT WOS:000231326900004 ER PT J AU Doherty, AC Parrilo, PA Spedalieri, FM AF Doherty, AC Parrilo, PA Spedalieri, FM TI Detecting multipartite entanglement SO PHYSICAL REVIEW A LA English DT Article ID STATE EXTENSION PROBLEM; DENSITY-MATRICES; QUANTUM-SYSTEMS; SEPARABILITY; DISTILLABILITY AB We discuss the problem of determining whether the state of several quantum mechanical subsystems is entangled. As in previous work on two subsystems we introduce a procedure for checking separability that is based on finding state extensions with appropriate properties and may be implemented as a semidefinite program. The main result of this work is to show that there is a series of tests of this kind such that if a multiparty state is entangled this will eventually be detected by one of the tests. The procedure also provides a means of constructing entanglement witnesses that could in principle be measured in order to demonstrate that the state is entangled. C1 Univ Queensland, Sch Phys Sci, St Lucia, Qld 4072, Australia. CALTECH, Inst Quantum Informat, Pasadena, CA 91125 USA. ETH Zentrum, Inst Automat, CH-8092 Zurich, Switzerland. CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, Pasadena, CA 91109 USA. RP Univ Queensland, Sch Phys Sci, St Lucia, Qld 4072, Australia. RI Doherty, Andrew/D-1816-2010; OI Doherty, Andrew/0000-0002-8069-7754; Parrilo, Pablo/0000-0003-1132-8477 NR 52 TC 56 Z9 56 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9926 EI 2469-9934 J9 PHYS REV A JI Phys. Rev. A PD MAR PY 2005 VL 71 IS 3 AR 032333 DI 10.1103/PhysRevA.71.032333 PN A PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 919QH UT WOS:000228632100048 ER PT J AU Matsko, AB Savchenkov, AA Strekalov, D Ilchenko, VS Maleki, L AF Matsko, AB Savchenkov, AA Strekalov, D Ilchenko, VS Maleki, L TI Optical hyperparametric oscillations in a whispering-gallery-mode resonator: Threshold and phase diffusion SO PHYSICAL REVIEW A LA English DT Article ID SELF-OSCILLATION; SODIUM VAPOR; MICROCAVITIES; CAVITY; WAVE; INSTABILITIES; CONVERSION; FIBERS; GAIN AB We present a theoretical analysis of optical parametric oscillations through four-wave mixing in a nonlinear high-Q whispering-gallery-mode resonator. It is shown that even a small flux of pump photons is sufficient to reach the threshold of the oscillations. We demonstrate that due to narrow bandwidth of the resonator modes as well as the high efficiency of the resonant frequency conversion the oscillator produces a stable narrow-band beat note of the pump, signal, and idler waves making an all-optical secondary frequency reference feasible. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Matsko, AB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Matsko, Andrey/A-1272-2007 NR 28 TC 81 Z9 81 U1 2 U2 27 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 MAR PY 2005 VL 71 IS 3 AR 033804 DI 10.1103/PhysRevA.71.033804 PN B PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 919QK UT WOS:000228632400059 ER PT J AU Foygel, M Morris, RD Anez, D French, S Sobolev, VL AF Foygel, M Morris, RD Anez, D French, S Sobolev, VL TI Theoretical and computational studies of carbon nanotube composites and suspensions: Electrical and thermal conductivity SO PHYSICAL REVIEW B LA English DT Article ID CONTINUUM PERCOLATION; EXCLUDED-VOLUME; STICKS; DISPERSION; THRESHOLD; COMPUTER; BEHAVIOR; SYSTEM; RODS AB Monte Carlo simulations have been performed, aimed at finding a critical fractional volume (CFV) associated with the onset of percolation for randomly oriented nanotubes (or, indeed, any conductive particles with large aspect ratios) that are randomly dispersed in a low thermo- or electroconductive medium. The nanotubes were treated as capped interpenetrating conductive cylinders ("sticks") with high (up to 2000) aspect ratio a. It has been found that for these aspect ratios the CFV is inversely proportional to a resulting in surprisingly low filler volume loadings, of the order of 0.01%, required to achieve percolation in such systems. By studying fluctuations of the CFV and the density of the percolation clusters, various critical indices of the percolation theory have been calculated including the critical index of conductivity, t. For three-dimensional systems it has been found that t decreases substantially with an increase in the aspect ratio. The calculated thermal and electrical conductivity of the nanotube suspensions and composites as functions of the nanotube loading is in good agreement with recent experimental data. C1 S Dakota Sch Mines & Technol, Dept Phys, Rapid City, SD 57701 USA. NASA, USRA, RIACS, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Foygel, M (reprint author), S Dakota Sch Mines & Technol, Dept Phys, 501 St Joseph St, Rapid City, SD 57701 USA. RI French, Samuel/A-3100-2012 NR 24 TC 236 Z9 237 U1 5 U2 74 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 MAR PY 2005 VL 71 IS 10 AR 104201 DI 10.1103/PhysRevB.71.104201 PG 8 WC Physics, Condensed Matter SC Physics GA 912GK UT WOS:000228065400024 ER PT J AU Mehrez, H Anantram, MP AF Mehrez, H Anantram, MP TI Interbase electronic coupling for transport through DNA SO PHYSICAL REVIEW B LA English DT Article ID ELECTRICAL-CONDUCTION; CHARGE MIGRATION; MOLECULES; DISORDER AB We develop an approach to derive single-state tight-binding (SSTB) model for electron transport in the vicinity of valence-conduction bands of poly(G)-poly(C) and poly(A)-poly(T) DNA. The SSTB parameters are derived from first principles and are used to model charge transport through finite length DNA. We investigate the rigor of reducing the full DNA Hamiltonian to SSTB model. While the transmission coefficient spectrum is preserved, its position shifts in energy. Thymine is poorly represented and its peak height is substantially reduced. This is attributed to the abstraction of the HOMO-LUMO (HOMO, highest occupied molecular orbital; LUMO, lowest unoccupied molecular orbital) coupling to other eigenstates in the nearest-neighbor DNA bases, and can be corrected within second-order time-independent perturbation theory. Interstrand charge transport has also been analyzed and it is found that hopping to the nearest neighbor in the complementary strand is the most important process except in the valence band of poly(G)-poly(C), where hopping to the second nearest neighbor between 3'-ends is the most dominant process. As a result, transport between 3'-ends and 5'-ends in the vicinity of valence band of poly(G)-poly(C) is asymmetric. C1 NASA, Ames Res Ctr, Ctr NanoTechnol, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, NASA Adv Supercomp Div, Moffett Field, CA 94035 USA. RP Mehrez, H (reprint author), NASA, Ames Res Ctr, Ctr NanoTechnol, Mail Stop 229-1, Moffett Field, CA 94035 USA. NR 33 TC 73 Z9 74 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD MAR PY 2005 VL 71 IS 11 AR 115405 DI 10.1103/PhysRevB.71.115405 PG 5 WC Physics, Condensed Matter SC Physics GA 912GL UT WOS:000228065500114 ER PT J AU Kidder, LE Lindblom, L Scheel, MA Buchman, LT Pfeiffer, HP AF Kidder, LE Lindblom, L Scheel, MA Buchman, LT Pfeiffer, HP TI Boundary conditions for the Einstein evolution system SO PHYSICAL REVIEW D LA English DT Article ID AXISYMMETRICAL GRAVITATIONAL COLLAPSE; GENERAL-RELATIVITY; EQUATIONS; FIELD AB New boundary conditions are constructed and tested numerically for a general first-order form of the Einstein evolution system. These conditions prevent constraint violations from entering the computational domain through timelike boundaries, allow the simulation of isolated systems by preventing physical gravitational waves from entering the computational domain, and are designed to be compatible with the fixed-gauge e volutions used here. These new boundary conditions are shown to be effective in limiting the growth of constraints in 3D nonlinear numerical evolutions of dynamical black-hole spacetimes. C1 Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. NR 46 TC 51 Z9 51 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 MAR PY 2005 VL 71 IS 6 AR 064020 DI 10.1103/PhysRevD.71.064020 PG 22 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 917SS UT WOS:000228490100065 ER PT J AU Broks, BHP Brok, WJM Remy, J van der Mullen, JJAM Benidar, A Biennier, L Salama, F AF Broks, BHP Brok, WJM Remy, J van der Mullen, JJAM Benidar, A Biennier, L Salama, F TI Numerical investigation of the discharge characteristics of the pulsed discharge nozzle SO PHYSICAL REVIEW E LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; PAH CATIONS; ARGON; SPECTROSCOPY; IONIZATION; JET; IDENTIFICATION; ELECTRONS; BREAKDOWN; RADICALS AB The characteristics of the plasma generated by a pulsed discharge slit nozzle (PDN) are investigated. The PDN source is designed to produce and cool molecular ions creating an astrophysically relevant environment in the laboratory. A discharge model is applied to this system to provide a qualitative as well as a quantitative picture of the plasma. We find that the plasma's properties and behavior are characteristic of those of a glow discharge. We model the electron density and energy, as well as the argon ion and metastable atom number density. The results reveal a high abundance of metastable argon atoms in the expansion region, which is more than one order of magnitude higher than the abundance of electrons and ions. These findings confirm experimental observations, which concluded that large molecular ions are dominantly formed through Penning ionization of the neutral molecular precursors seeded in the supersonic expansion of argon gas. The simulations presented here will help optimize the yield of formation of molecular ions and radicals in the PDN source; they will also provide key physical insight into the characteristics of interstellar molecules and ions analogs in laboratory experiments. C1 Eindhoven Univ Technol, Dept Appl Phys, NL-5600 MB Eindhoven, Netherlands. Univ Rennes 1, UMR 6627, Lab Phys Atomes Lasers Mol & Surfaces, F-35042 Rennes, France. NASA, Div Space Sci, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Eindhoven Univ Technol, Dept Appl Phys, POB 513, NL-5600 MB Eindhoven, Netherlands. EM j.j.a.m.v.d.mullen@tue.nl RI Salama, Farid/A-8787-2009; Biennier, Ludovic/O-1618-2014; benidar, abdessamad/O-1624-2014 OI Salama, Farid/0000-0002-6064-4401; NR 35 TC 12 Z9 13 U1 1 U2 7 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 MAR PY 2005 VL 71 IS 3 AR 036409 DI 10.1103/PhysRevE.71.036409 PN 2 PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 922EC UT WOS:000228818200114 PM 15903590 ER PT J AU Balasubramaniam, R Subramanian, RS AF Balasubramaniam, R Subramanian, RS TI Response to "Comment on 'Thermocapillary convection due to a stationary bubble'" [Phys. Fluids 17, 039101 (2005)] SO PHYSICS OF FLUIDS LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, Cleveland, OH 44135 USA. Clarkson Univ, Potsdam, NY 13699 USA. RP Balasubramaniam, R (reprint author), NASA, Glenn Res Ctr, Natl Ctr Micrograv Res Fluids & Combust, Cleveland, OH 44135 USA. NR 2 TC 1 Z9 1 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 1070-6631 J9 PHYS FLUIDS JI Phys. Fluids PD MAR PY 2005 VL 17 IS 3 AR 039102 DI 10.1063/1.1862213 PG 1 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 902QW UT WOS:000227372600073 ER PT J AU Comiso, J Parkinson, C AF Comiso, J Parkinson, C TI Coastline changes from melting ice sheets - Comiso and Parkinson reply SO PHYSICS TODAY LA English DT Letter C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Comiso, J (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM josefino.c.comiso@nasa.gov; claire.l.parkinson@nasa.gov RI Parkinson, Claire/E-1747-2012 OI Parkinson, Claire/0000-0001-6730-4197 NR 2 TC 0 Z9 0 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 0031-9228 J9 PHYS TODAY JI Phys. Today PD MAR PY 2005 VL 58 IS 3 BP 12 EP 12 PG 1 WC Physics, Multidisciplinary SC Physics GA 901VE UT WOS:000227309400006 ER PT J AU Bailey, SG Morton, T AF Bailey, SG Morton, T TI Progress in Space Photovoltaics SO PROGRESS IN PHOTOVOLTAICS LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Photovoltaics & Space Environm Branch, Cleveland, OH 44135 USA. RP Bailey, SG (reprint author), NASA, Glenn Res Ctr, Photovoltaics & Space Environm Branch, 21000 Brookpk Rd, Cleveland, OH 44135 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD MAR PY 2005 VL 13 IS 2 BP 91 EP 91 DI 10.1002/pip.600 PG 1 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 904RV UT WOS:000227516300001 ER PT J AU Landi, BJ Raffaelle, RP Castro, SL Bailey, SG AF Landi, BJ Raffaelle, RP Castro, SL Bailey, SG TI Single-wall carbon nanotube-polymer solar cells SO PROGRESS IN PHOTOVOLTAICS LA English DT Article; Proceedings Paper CT 18th Space Photovoltaic Research and Technology (SPRAT 18 ) CY SEP 16-18, 2003 CL Ohio Aerospace Inst, Cleveland, OH SP NASA Glenn Res Ctr, Photovolta & Space Environm Effects Branch HO Ohio Aerospace Inst DE carbon nanotube; P30T; polymer solar cell ID PHOTOVOLTAIC DEVICES; OPTICAL-PROPERTIES; COMPOSITES; SPECTROSCOPY; ROPES AB Investigation of single-wall carbon nanotube (SWNT)-polymer solar cells has been conducted towards developing alternative lightweight, flexible devices for space power applications. Photovoltaic devices were constructed with regioregular poly(3-octylthiophene)-(P3OT) and purified, >95% w/w, laser-generated SWNTs. The P3OT composites were deposited on ITO-coated polyethylene terapthalate (PET) and I-V characterization was performed under simulated AM0 illumination. Fabricated devices for the 1.0% w/w SWNT-P3OT composites showed a photoresponse with an open-circuit voltage V-oc of 0.98 V and a short-circuit current density (I-sc) of 0.12 mA/cm(2). Future optimization of carrier transport and exciton dissociation within these novel photovoltaic systems is proposed to derive from incorporation of nanostructure-SWNT complexes into the polymer. Copyright (C) 2005 John Wiley Sons, Ltd. C1 Rochester Inst Technol, NanoPower Res Labs, Rochester, NY 14623 USA. Ohio Aerosp Inst, Brookpark, OH 44142 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Raffaelle, RP (reprint author), Rochester Inst Technol, NanoPower Res Labs, Rochester, NY 14623 USA. EM rprsps@rit.edu NR 27 TC 175 Z9 178 U1 1 U2 38 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1062-7995 J9 PROG PHOTOVOLTAICS JI Prog. Photovoltaics PD MAR PY 2005 VL 13 IS 2 BP 165 EP 172 DI 10.1002/pip.604 PG 8 WC Energy & Fuels; Materials Science, Multidisciplinary; Physics, Applied SC Energy & Fuels; Materials Science; Physics GA 904RV UT WOS:000227516300010 ER PT J AU Anderson, MS Andringa, JM Carlson, RW Conrad, P Hartford, W Shafer, M Soto, A Tsapin, AI Dybwad, JP Wadsworth, W Hand, K AF Anderson, MS Andringa, JM Carlson, RW Conrad, P Hartford, W Shafer, M Soto, A Tsapin, AI Dybwad, JP Wadsworth, W Hand, K TI Fourier transform infrared spectroscopy for Mars science SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID REFLECTANCE SPECTROSCOPY; SPECTROMETRY; EXPLORATION; MINERALS; WATER; SOIL AB Presented here is a Fourier transform infrared spectrometer (FTIR) for field studies that serves as a prototype for future Mars science applications. Infrared spectroscopy provides chemical information that is relevant to a number of Mars science questions. This includes mineralogical analysis, nitrogen compound recognition, truth testing of remote sensing measurements, and the ability to detect organic compounds. The challenges and scientific opportunities are given for the in situ FTIR analysis of Mars soil and rock samples. Various FTIR sampling techniques are assessed and compared to other analytical instrumentation. The prototype instrument presented is capable of providing field analysis in a Mars analog Antarctic environment. FTIR analysis of endolithic microbial communities in Antarctic rocks and a Mars meteor are given as analytical examples. (C) 2005 American Institute of Physics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Designs & Prototypes Ltd, Nashua, NH 03064 USA. Stanford Univ, Stanford, CA 94305 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Mark.S.Anderson@jpl.nasa.gov RI Conrad, Pamela/F-1506-2012; OI Conrad, Pamela/0000-0001-8805-7981; Soto, Alejandro/0000-0002-2333-0307 NR 27 TC 14 Z9 14 U1 0 U2 4 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0034-6748 EI 1089-7623 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD MAR PY 2005 VL 76 IS 3 AR 034101 DI 10.1063/1.1867012 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 904WV UT WOS:000227530200033 ER PT J AU Wergin, WP Erbe, EF Rango, A Foster, J Pooley, C AF Wergin, WP Erbe, EF Rango, A Foster, J Pooley, C TI Low temperature scanning electron microscopy of artificial snow SO SCANNING LA English DT Article; Proceedings Paper CT 16th Annual Scanning Conference CY APR 05-07, 2005 CL Monterey, CA SP Fdn Advances Med & Sci C1 USDA ARS, Soybean Genom & Improvement Lab, Beltsville, MD 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. USDA ARS, Hydrol & Remote Sensing Lab, Beltsville, MD USA. RP Wergin, WP (reprint author), USDA ARS, Soybean Genom & Improvement Lab, Beltsville, MD USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430-0832 USA SN 0161-0457 J9 SCANNING JI Scanning PD MAR-APR PY 2005 VL 27 IS 2 BP 63 EP 64 PG 2 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA 909GQ UT WOS:000227848800007 ER PT J AU Steinberg, SL Poritz, D AF Steinberg, SL Poritz, D TI Measurement of hydraulic characteristics of porous media used to grow plants in microgravity SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID UNSATURATED SOILS; IN-SPACE; CONDUCTIVITY; FLOW AB Understanding the effect of gravity on hydraulic properties of plant growth medium is essential for growing plants in space. The suitability of existing models to simulate hydraulic properties of porous medium is uncertain due to limited understanding of fundamental mechanisms controlling water and air transport in microgravity. The objective of this research was to characterize saturated and unsaturated hydraulic conductivity (K) of two particle-size distributions of baked ceramic aggregate using direct measurement techniques compatible with microgravity. Steady state (Method A) and instantaneous profile measurement (Method B) methods for K were used in a single experimental unit with horizontal flow through thin sections of porous medium providing an earth-based analog to microgravity. Comparison between methods was conducted using a crossover experimental design compatible with limited resources of space flight. Satiated (natural saturation) K ranged from 0.09 to 0.12 cm s(-1) and 0.5 to > 1 cm s(-1) for 0.25- to 1- and 1- to 2-mm media, respectively. The K at the interaggregate/intraaggregate transition was approximate to 10(-4) cm s(-1) for both particle-size distributions. Significant differences in log(10)K due to method and porous medium were less than one order of magnitude and were attributed to variability in air entrapment. The van Genuchten/Mualem parametric models provided an adequate prediction of K of the interaggregate pore space, using residual water content for that pore space. The instantaneous profile method covers the range of water contents relevant to plant growth using fewer resources than Method A, all advantages for space flight where mass, volume, and astronaut time are limited. C1 Univ Space Res Assoc, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Steinberg, SL (reprint author), Univ Space Res Assoc, Mail Code EC3, Houston, TX 77058 USA. EM susan.l.steinberg1@jsc.nasa.gov NR 30 TC 8 Z9 8 U1 1 U2 3 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD MAR-APR PY 2005 VL 69 IS 2 BP 301 EP 310 PG 10 WC Soil Science SC Agriculture GA 908KZ UT WOS:000227787200002 PM 16052740 ER PT J AU Sutter, B Hossner, LR Ming, DW AF Sutter, B Hossner, LR Ming, DW TI Dissolution kinetics of iron-, manganese-, and copper-containing synthetic hydroxyapatites SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID SOLUBILITY; GROWTH; WHEAT; ACID; DEMINERALIZATION; PHOSPHATE; RESONANCE; SOILS; IONS; PH AB Micronutrient-substituted synthetic hydroxyapatite (SHA) is being evaluated by the National Aeronautics and Space Administration's (NASA) Advanced Life Support (ALS) Program for crop production on long-duration human missions to the International Space Station or for future Lunar or Martian outposts. The stirred-flow technique was utilized to characterize Ca, P, Fe, Mn, and Cu release characteristics from Fe-, Mn-, and Cu-containing SHA in deionized (DI) water, citric acid, and diethylene-triamine-pentaacetic acid (DTPA). Initially, Ca and P release rates decreased rapidly with time and were controlled by a non-SHA calcium phosphate phase(s) with low Ca/P solution molar ratios (0.91-1.51) relative to solid SHA ratios (1.56-1.64). At later times, Ca/P solution molar ratios (1.47-1.79) were near solid SHA ratios and release rates decreased slowly indicating that SHA controlled Ca and P release. Substituted SHA materials had faster dissolution rates relative to unsubstituted SHA. The initial metal release rate order was Mn >> Cu > Fe which followed metal-oxide/phosphate solubility suggesting that poorly crystalline metal-oxides/phosphates were dominating metal release. Similar metal release rates for all substituted SHA (approximately 0.01 cmol kg(-1) min(-1)) at the end of the DTPA experiment indicated that SHA dissolution was supplying the metals into solution and that poorly crystalline metaloxide/phosphates were not controlling metal release. Results indicate that non-SHA Ca-phosphate phases and poorly crystalline metaloxide/phosphates will contribute Ca, P, and metals. After these phases have dissolved, substituted SHA will be the source of Ca, P, and metals for plants. C1 Texas A&M Univ, Dept Soil & Crop Sci, College Stn, TX 77843 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Sutter, B (reprint author), NASA, Ames Res Ctr, SETI Inst, Moffett Field, CA 94035 USA. EM bsutter@mail.arc.nasa.gov NR 38 TC 5 Z9 5 U1 5 U2 16 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD MAR-APR PY 2005 VL 69 IS 2 BP 362 EP 370 PG 9 WC Soil Science SC Agriculture GA 908KZ UT WOS:000227787200009 PM 16052742 ER PT J AU Sturrock, PA Scargle, JD Walther, G Wheatland, MS AF Sturrock, PA Scargle, JD Walther, G Wheatland, MS TI Combined and comparative analysis of power spectra SO SOLAR PHYSICS LA English DT Article ID SOLAR-NEUTRINO FLUX; CAPTURE RATE; CYCLE MODULATION; TIME-SERIES; PERIODICITY; OSCILLATIONS; FLARES AB In solar physics, especially in exploratory stages of research, it is often necessary to compare the power spectra of two or more time series. One may, for instance, wish to estimate what the power spectrum of the combined data sets might have been, or one may wish to estimate the significance of a particular peak that shows up in two or more power spectra. One may also on occasion need to search for a complex of peaks in a single power spectrum, such as a fundamental and one or more harmonics, or a fundamental plus sidebands, etc. Visual inspection can be revealing, but it can also be misleading. This leads one to look for one or more ways of forming statistics, which readily lend themselves to significance estimation, from two or more power spectra. We derive formulas for statistics formed from the sum, the minimum, and the product of two or more power spectra. A distinguishing feature of our formulae is that, if each power spectrum has an exponential distribution, each statistic also has an exponential distribution. The statistic formed from the minimum power of two or more power spectra is well known and has an exponential distribution. The sum of two or more powers also has a well-known distribution that is not exponential, but a simple operation does lead to an exponential distribution. Concerning the product of two or more power spectra, we find an analytical expression for the case n = 2, and a procedure for computing the statistic for n > 2. We also show that some quite simple expressions give surprisingly good approximations. C1 Stanford Univ, Ctr Space Sci & Astrophys, Stanford, CA 94305 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Stanford Univ, Dept Stat, Stanford, CA 94305 USA. Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia. RP Stanford Univ, Ctr Space Sci & Astrophys, Stanford, CA 94305 USA. EM sturrock@stanford.edu RI Wheatland, Michael/G-1958-2016 OI Wheatland, Michael/0000-0001-5100-2354 NR 38 TC 21 Z9 22 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 EI 1573-093X J9 SOL PHYS JI Sol. Phys. PD MAR PY 2005 VL 227 IS 1 BP 137 EP 153 DI 10.1007/s11207-005-7424-x PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 932UL UT WOS:000229578900008 ER PT J AU Dlugach, ZM Mishchenko, MI AF Dlugach, ZM Mishchenko, MI TI The effect of aerosol shape in retrieving optical properties of cloud particles in the planetary atmospheres from the photopolarimetric data Jupiter SO SOLAR SYSTEM RESEARCH LA English DT Article ID WAVELENGTH DEPENDENCE; TROPOSPHERIC AEROSOLS; MARTIAN ATMOSPHERE; VENUS; POLARIZATION; SCATTERING; LIGHT; ICE AB The influence of the assumed shape of aerosols on the estimates of the refractive index and size of particles (based on the data of ground-based spectropolarimetric measurements) is investigated for Jupiter's cloud layer. In the present analysis, we supposed the atmospheric particles to be chaotically oriented spheroids and cylinders with a gamma size distribution. Their single-scattering characteristics were calculated with the T-matrix method, and the intensity and degree of linear polarization of the radiation reflected by the center of the planetary disk were found by solving the vector radiative-transfer equation with consideration for multiple scattering in a plane-parallel atmosphere. We considered a spectral interval from 0.423 to 0.798 pm and phase angles a from 0&DEG; to 11&DEG;. It has been shown that, if we use the optical characteristics of aerosols found within the frames of a spherical model (Mishchenko, 1990a), the models with the nonspherical particles considered here cannot fit the observational data. The refractive index and the sizes of spheroidal and cylindrical particles were estimated from a comparison of the data of measurements and calculations, and the simplest models for the Jovian cloud layer structure have been considered. We have concluded that the optical parameters of cloud particles (specifically, the refractive index) cannot be reliably estimated only on the basis of measurements made in a narrow ran e of phase angles. C1 Natl Acad Sci Ukraine, Main Astron Observ, UA-03680 Kiev, Ukraine. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Dlugach, ZM (reprint author), Natl Acad Sci Ukraine, Main Astron Observ, 27 Zalolotny Ul, UA-03680 Kiev, Ukraine. RI Mishchenko, Michael/D-4426-2012 NR 26 TC 10 Z9 10 U1 0 U2 2 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 MAR-APR PY 2005 VL 39 IS 2 BP 102 EP 111 DI 10.1007/s11208-005-0026-1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 924BJ UT WOS:000228953300002 ER PT J AU Dykas, B Howard, SA AF Dykas, B Howard, SA TI Journal design considerations for turbomachine shafts supported on foil air bearings((c)) SO TRIBOLOGY & LUBRICATION TECHNOLOGY LA English DT Reprint DE foil bearing; journal; thermal effects ID OIL-FREE TURBOMACHINERY; PERFORMANCE AB Foil air bearings can offer substantial improvements over traditional rolling element bearings in many applications, and are attractive as a replacement to enable the development of advanced Oil-Free Turbo-machinery. In the course of rigorous testing of foil journal bearings at NASA Glenn Research Center, shaft failure was repeatedly encountered at high ambient temperature and rotational speed, with moderate radial load. The cause of failure is determined to be excessive non-uniform shaft growth which increases localized viscous heating in the gas film, and eventually leading to a high speed rub and destruction of the bearing and journal. Centrifugal loading of imbalance correction weights and axial temperature gradients within the journal due to the hydrodynamic nature of the foil bearings, determined by experiment and finite element analysis, are shown to be responsible for the nonuniform growth. Qualitative journal design guidance is given to aid in failure prevention. C1 Case Western Reserve Univ, Cleveland, OH 44106 USA. NASA, Glenn Res Ctr, Cleveland, OH USA. RP Dykas, B (reprint author), Case Western Reserve Univ, Cleveland, OH 44106 USA. NR 17 TC 1 Z9 1 U1 0 U2 1 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 0024-7154 J9 TRIBOL LUBR TECHNOL JI Tribol. Lubr. Technol. PD MAR PY 2005 VL 61 IS 3 BP 46 EP 54 PG 9 WC Engineering, Mechanical SC Engineering GA 906FM UT WOS:000227625900011 ER PT J AU Szewczyk, NJ McLamb, W AF Szewczyk, NJ McLamb, W TI Surviving atmospheric spacecraft breakup SO WILDERNESS & ENVIRONMENTAL MEDICINE LA English DT Article DE Caenorhabditis elegans; rescue work; disasters; life-support systems; astronauts; space flight ID NEMATODE CAENORHABDITIS-ELEGANS; CHEMICALLY-DEFINED MEDIUM AB Spacecraft travel higher and faster than aircraft, making breakup potentially less survivable. As with aircraft breakup, the dissipation of lethal forces via spacecraft breakup around an organism is likely to greatly increase the odds of survival. By employing a knowledge of space and aviation physiology, comparative physiology, and search-and-rescue techniques, we were able to correctly predict and execute the recovery of live animals following the breakup of the space shuttle Columbia. In this study, we make what is, to our knowledge, the first report of an animal, Caenorhabditis elegans, surviving the atmospheric breakup of the spacecraft that was supporting it and discuss both the lethal events these animals had to escape and the implications for search and rescue following spacecraft breakup. C1 NASA, Ames Res Ctr, Space Life Res & Disaster Assistance & Rescue Tea, Moffett Field, CA 94035 USA. Bionet Corp, Kennedy Space Ctr, FL USA. RP Szewczyk, NJ (reprint author), NASA, Ames Res Ctr, Space Life Res & Disaster Assistance & Rescue Tea, M-S 239-11, Moffett Field, CA 94035 USA. EM nate@alumni.cmu.edu NR 25 TC 6 Z9 6 U1 1 U2 2 PU ALLIANCE COMMUNICATIONS GROUP DIVISION ALLEN PRESS PI LAWRENCE PA 810 EAST 10TH STREET, LAWRENCE, KS 66044 USA SN 1080-6032 J9 WILD ENVIRON MED JI Wildern. Environ. Med. PD SPR PY 2005 VL 16 IS 1 BP 27 EP 32 DI 10.1580/PR21-03.1 PG 6 WC Public, Environmental & Occupational Health; Sport Sciences SC Public, Environmental & Occupational Health; Sport Sciences GA 911CP UT WOS:000227979400006 PM 15813144 ER PT J AU Singleton, CS Randall, CE Chipperfield, MP Davies, S Feng, W Bevilacqua, RM Hoppel, KW Fromm, MD Manney, GL Harvey, VL AF Singleton, C. S. Randall, C. E. Chipperfield, M. P. Davies, S. Feng, W. Bevilacqua, R. M. Hoppel, K. W. Fromm, M. D. Manney, G. L. Harvey, V. L. TI 2002-2003 Arctic ozone loss deduced from POAM III satellite observations and the SLIMCAT chemical transport model SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID STRATOSPHERIC POLAR VORTEX; 3-DIMENSIONAL MODEL; WINTER; DEPLETION; RECONSTRUCTION; SIMULATIONS; VARIABILITY; VALIDATION; DESCENT AB The SLIMCAT three-dimensional chemical transport model ( CTM) is used to infer chemical ozone loss from Polar Ozone and Aerosol Measurement ( POAM) III observations of stratospheric ozone during the Arctic winter of 2002-2003. Inferring chemical ozone loss from satellite data requires quantifying ozone variations due to dynamical processes. To accomplish this, the SLIMCAT model was run in a "passive" mode from early December until the middle of March. In these runs, ozone is treated as an inert, dynamical tracer. Chemical ozone loss is inferred by subtracting the model passive ozone, evaluated at the time and location of the POAM observations, from the POAM measurements themselves. This "CTM Passive Subtraction" technique relies on accurate initialization of the CTM and a realistic description of vertical/horizontal transport, both of which are explored in this work. The analysis suggests that chemical ozone loss during the 2002-2003 winter began in late December. This loss followed a prolonged period in which many polar stratospheric clouds were detected, and during which vortex air had been transported to sunlit latitudes. A series of stratospheric warming events starting in January hindered chemical ozone loss later in the winter of 2003. Nevertheless, by 15 March, the final date of the analysis, ozone loss maximized at 425K at a value of about 1.2 ppmv, a moderate amount of loss compared to loss during the unusually cold winters in the late-1990s. SLIMCAT was also run with a detailed stratospheric chemistry scheme to obtain the model-predicted loss. The SLIMCAT model simulation also shows a maximum ozone loss of 1.2 ppmv at 425 K, and the morphology of the loss calculated by SLIMCAT was similar to that inferred from the POAM data. These results from the recently updated version of SLIMCAT therefore give a much better quantitative description of polar chemical ozone loss than older versions of the same model. Both the inferred and modeled loss calculations show the early destruction in late December and the region of maximum loss descending in altitude through the remainder of the winter and early spring. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Univ Leeds, Sch Earth & Environm, Inst Atmospher Sci, Leeds LS2 9JT, W Yorkshire, England. USN, Res Lab, Remote Sensing Phys Branch, Washington, DC 20375 USA. Computat Phys Inc, Springfield, VA 22151 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. New Mexico Highlands Univ, Dept Nat Sci, Las Vegas, NM 87701 USA. RP Singleton, CS (reprint author), Univ Colorado, Atmospher & Space Phys Lab, UCB 392, Boulder, CO 80309 USA. EM shaw@lasp.colorado.edu RI FENG, WUHU/B-8327-2008; Fromm, Michael/F-4639-2010; Chipperfield, Martyn/H-6359-2013; Randall, Cora/L-8760-2014 OI FENG, WUHU/0000-0002-9907-9120; Chipperfield, Martyn/0000-0002-6803-4149; Randall, Cora/0000-0002-4313-4397 NR 40 TC 32 Z9 32 U1 0 U2 4 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 FEB 28 PY 2005 VL 5 BP 597 EP 609 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 901XP UT WOS:000227315900001 ER PT J AU Ciesla, F Lauretta, D AF Ciesla, F Lauretta, D TI Radial migration and dehydration of phyllosilicates in the solar nebula SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE solar nebula; meteorites; water; planet formation ID WATER; EVOLUTION; ORIGIN; METEORITE; ACCRETION; DELIVERY; BODIES; EARTH; DISKS AB While it is currently thought that Earth's water was delivered by hydrous minerals, the origin of these minerals is still debated. Nebular models suggest that the area where the Earth formed was too hot for these minerals to form, leading many to believe that they were delivered by large planetary embryos which formed in the outer asteroid belt region of the solar nebula. Others have argued that the hydrous minerals were present during the early accretion phase of the Earth in order to explain different aspects of its geochemistry and therefore, must have formed locally, implying that the nebula must have been cooler than the models predict. In this paper we explore a new possibility: that these hydrous minerals were formed in the outer asteroid belt region of the solar nebula and were then brought into the hotter regions of the nebula by gas drag where they were incorporated into the planetesimals which formed there. The hydrated minerals were able to survive for long periods of time in this hot region due to the sluggish dehydration kinetics. We find that this process need not have been efficient, requiring only a small amount (similar tofew percentages) of the material in the outer asteroid belt region of the nebula to be subject to this process. This delivery mechanism provides a way for hydrous minerals to be incorporated early on into the planetesimals which were accreted by the Earth without having to alter the generally accepted solar nebula models that are consistent with meteoritic and asteroidal observations. (C) 2005 Elsevier B.V. All rights reserved. C1 NASA, Ames Res Ctr, Moffett Field, CA 94043 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. RP Ciesla, F (reprint author), NASA, Ames Res Ctr, MS 245-3, Moffett Field, CA 94043 USA. EM ciesla@cosmic.arc.nasa.gov; lauretta@lpl.arizona.edu NR 33 TC 21 Z9 21 U1 1 U2 4 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 FEB 28 PY 2005 VL 231 IS 1-2 BP 1 EP 8 DI 10.1016/j.epsl.2004.12.022 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 904ST UT WOS:000227518700001 ER PT J AU Stroupe, AW Balch, T AF Stroupe, AW Balch, T TI Value-based action selection for observation with robot teams using probabilistic techniques SO ROBOTICS AND AUTONOMOUS SYSTEMS LA English DT Article; Proceedings Paper CT 11th International Conference on Advanced Robotics (ICAR 2003) CY JUN 30-JUL 03, 2003 CL COIMBRA, PORTUGAL SP Inst Syst & Robot, Univ Coimbra, IEEE Portugees Sect, IEEE Robot & Automat Soc, IEEE Ind Electr Soc, Robot Soc Japan, Japan Robot Assoc DE multi-robot cooperation; robot action selection; mapping AB We present an approach for directing next-step movements of robot teams engaged in mapping objects in their environment: Move Value Estimation for Robot Teams (MVERT). Resulting robot paths tend to optimize vantage points for all robots on the team by maximizing information gain. At each step, each robot selects a movement to maximize the utility (in this case, reduction in uncertainty) of its next observation. Trajectories are not guaranteed to be optimal, but team behavior serves to maximize the team's knowledge since each robot considers the observational contributions of team mates. MVERT is evaluated in simulation by measuring the resulting uncertainty about target locations compared to that obtained by robots acting without regard to team mate locations and to that of global optimization over all robots for each single step. Additionally, MVERT is demonstrated on physical teams of robots. The qualitative behavior of the team is appropriate and close to the single-step optimal set of trajectories. (C) 2004 Elsevier B.V. All rights reserved. C1 Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Georgia Inst Technol, Atlanta, GA 30332 USA. RP Stroupe, AW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS-82105, Pasadena, CA 91109 USA. EM ashley@ri.cmu.edu; tucker@cc.gatech.edu NR 18 TC 20 Z9 20 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-8890 J9 ROBOT AUTON SYST JI Robot. Auton. Syst. PD FEB 28 PY 2005 VL 50 IS 2-3 BP 85 EP 97 DI 10.1016/j.robot.2004.08.002 PG 13 WC Automation & Control Systems; Computer Science, Artificial Intelligence; Robotics SC Automation & Control Systems; Computer Science; Robotics GA 895GV UT WOS:000226849800002 ER PT J AU Yang, R Feeback, DL Wang, WJ AF Yang, R Feeback, DL Wang, WJ TI Microfabrication and test of a three-dimensional polymer hydro-focusing unit for flow cytometry applications SO SENSORS AND ACTUATORS A-PHYSICAL LA English DT Article DE SU-8; three-dimensional hydro-focusing; microfluidic; microchannel; cytometer ID CHAMBER AB This paper details a novel true three-dimensional (3D) hydro-focusing microcell sorter for micro-flow cytometry applications. The unit was microfabricated by means of SU-83D lithography. The 3D microstructure for coaxial sheathing was designed, microfabricated, and tested. Three-dimensional hydro-focusing capability was demonstrated with an experiment to sort labeled tanned sheep erythrocytes (red blood cells). This polymer hydro-focusing microstructure is easily microfabraicted and integrated with other polymer microfluidic structures. (C) 2004 Elsevier B.V. All rights reserved. C1 Louisiana State Univ, Dept Mech Engn, Baton Rouge, LA 70803 USA. NASA Johnson Space Ctr, Houston, TX 77058 USA. RP Wang, WJ (reprint author), Louisiana State Univ, Dept Mech Engn, 2513B CEBA, Baton Rouge, LA 70803 USA. EM wang@lsu.edu NR 17 TC 75 Z9 78 U1 0 U2 25 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0924-4247 J9 SENSOR ACTUAT A-PHYS JI Sens. Actuator A-Phys. PD FEB 28 PY 2005 VL 118 IS 2 BP 259 EP 267 DI 10.1016/j.sna.2004.09.001 PG 9 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 899CW UT WOS:000227123500013 ER PT J AU Garrett, HB Levin, SM Bolton, SJ Evans, RW Bhattacharya, B AF Garrett, HB Levin, SM Bolton, SJ Evans, RW Bhattacharya, B TI A revised model of Jupiter's inner electron belts: Updating the Divine radiation model SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SYNCHROTRON-RADIATION; MAGNETIC-FIELD; MAGNETOSPHERE; EMISSION AB In 1983, Divine presented a comprehensive model of the Jovian charged particle environment that has long served as a reference for missions to Jupiter. However, in situ observations by Galileo and synchrotron observations from Earth indicate the need to update the model in the inner radiation zone. Specifically, a review of the model for 1 MeV < E < 100 MeV trapped electrons suggests that, based on the new synchrotron observations, the pitch angle distributions within L < 4 need to be updated by introducing two additional components: one near the Jovian magnetic equator and one at high magnetic latitudes. We report modifications to the model that reproduce these observations. The new model improves the fit to synchrotron emission observations and remains consistent with the original fit to the in situ Pioneer and Voyager data. Further modifications incorporating observations from the Galileo and Cassini spacecraft will be reported in the future. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Gibbel Corp, Montrose, CA 91214 USA. CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr,MS 220-6, Pasadena, CA 91109 USA. EM henry.garrett@jpl.nasa.gov NR 18 TC 15 Z9 15 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 26 PY 2005 VL 32 IS 4 AR L04104 DI 10.1029/2004GL021986 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 904VG UT WOS:000227525600004 ER PT J AU Goldstein, ME Leib, SJ AF Goldstein, ME Leib, SJ TI The role of instability waves in predicting jet noise SO JOURNAL OF FLUID MECHANICS LA English DT Article ID SOUND; LAYERS AB There is a continuing debate about the role of linear instability waves in the prediction of jet noise. Parallel mean flow models, such as the one proposed by Lilley, usually neglect these waves because they cause the solution to become infinite. The result is then non-causal and can, therefore, be quite different from the more realistic causal solution, especially for the chaotic flows being considered here. The present paper solves the relevant acoustic equations for a non-parallel mean flow by using a vector Green's function approach and requiring that the mean flow be weakly non-parallel, i.e. requiring that the spread rate be small. It demonstrates that linear instability waves must be accounted for in order to construct a proper causal solution to the jet noise problem. Recent experimental results (e.g. see Tam, Goleblowski T Seiner 1996) show that the small-angle spectra radiated by supersonic jets are significantly different from those radiated at larger angles (say, at 90 degrees) and even exhibit dissimilar frequency scalings (i.e. they scale with Helmholtz number as opposed to Strouhal number). The present solution is (among other things) able to explain this rather puzzling experimental result. C1 NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Brookpark, OH 44142 USA. RP Goldstein, ME (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. NR 37 TC 33 Z9 34 U1 0 U2 5 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD FEB 25 PY 2005 VL 525 BP 37 EP 72 DI 10.1017/S0022112004002551 PG 36 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 908KX UT WOS:000227787000003 ER PT J AU Koch, D Hansen, J AF Koch, D Hansen, J TI Distant origins of Arctic black carbon: A Goddard Institute for Space Studies ModelE experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID LONG-RANGE TRANSPORT; AIR-POLLUTION; NORTH-AMERICA; ELEMENTAL TRACERS; ASIAN AEROSOLS; UNITED-STATES; MARCH 1983; MAUNA-LOA; HAZE; SULFATE AB Black carbon (BC) particles, derived from incomplete combustion of fossil fuels and biomass, may have a severe impact on the sensitive Arctic climate, possibly altering the temperature profile, cloud temperature and amount, the seasonal cycle, and the tropopause level and accelerating polar ice melting. We use the Goddard Institute for Space Studies general circulation model to investigate the origins of Arctic BC by isolating various source regions and types. The model suggests that the predominant sources of Arctic soot today are from south Asia (industrial and biofuel emissions) and from biomass burning. These are the primary global sources of BC (approximately 20% and 55%, respectively, of the global emissions), and BC aerosols in these regions are readily lofted to high altitudes where they may be transported poleward. According to the model the Arctic BC optical thickness is mostly from south Asia (30%) and from biomass (28%) (with slightly more than half of biomass coming from north of 40degreesN); North America, Russia, and Europe each contribute 10-15%. Russia, Europe, and south Asia each contribute about 20-25% of BC to the low-altitude springtime "Arctic haze." In the Arctic upper troposphere/lower stratosphere during the springtime, south Asia (30-50%) and low-latitude biomass (20-30%) are dominant, with a significant aircraft contribution (10-20%). Industrial S emissions are estimated to be weighted relatively more toward Russia and less toward south Asia (compared with BC). As a result, Russia contributes the most to Arctic sulfate optical thickness (24%); however, the south Asian contribution is also substantial (17%). Uncertainties derive from source estimates, model vertical mixing, and aerosol removal processes. Nevertheless, our results suggest that distant sources contribute more to Arctic pollution than is generally assumed. C1 Columbia Univ, NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Columbia Univ, NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM dkoch@giss.nasa.gov RI Lacis, Andrew/D-4658-2012; Jackman, Charles/D-4699-2012; Minnis, Patrick/G-1902-2010; Unger, Nadine/M-9360-2015; Shindell, Drew/D-4636-2012; Schmidt, Gavin/D-4427-2012; Del Genio, Anthony/D-4663-2012; Perlwitz, Judith/B-7201-2008; Miller, Ron/E-1902-2012; LU, C/C-6598-2008 OI Minnis, Patrick/0000-0002-4733-6148; Schmidt, Gavin/0000-0002-2258-0486; Del Genio, Anthony/0000-0001-7450-1359; Perlwitz, Judith/0000-0003-4061-2442; NR 63 TC 695 Z9 706 U1 18 U2 50 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 FEB 25 PY 2005 VL 110 IS D4 AR D04204 DI 10.1029/2004JD005296 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 904VM UT WOS:000227526200002 ER PT J AU Manney, GL Kruger, K Sabutis, JL Sena, SA Pawson, S AF Manney, GL Kruger, K Sabutis, JL Sena, SA Pawson, S TI The remarkable 2003-2004 winter and other recent warm winters in the Arctic stratosphere since the late 1990s SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID INTERANNUAL VARIABILITY; OZONE LOSS; POLAR VORTICES; CLIMATE-CHANGE; TEMPERATURE-CHANGES; CIRCULATION MODEL; MIDDLE ATMOSPHERE; FEBRUARY 1979; RECOVERY; TRENDS AB The 2003-2004 Arctic winter was remarkable in the similar to50- year record of meteorological analyses. A major warming beginning in early January 2004 led to nearly 2 months of vortex disruption with high-latitude easterlies in the middle to lower stratosphere. The upper stratospheric vortex broke up in late December, but began to recover by early January, and in February and March was the strongest since regular observations began in 1979. The lower stratospheric vortex broke up in late January. Comparison with 2 previous years, 1984-1985 and 1986-1987, with prolonged midwinter warming periods shows unique characteristics of the 2003-2004 warming period: The length of the vortex disruption, the strong and rapid recovery in the upper stratosphere, and the slow progression of the warming from upper to lower stratosphere. January 2004 zonal mean winds in the middle and lower stratosphere were over 2 standard deviations below average. Examination of past variability shows that the recent frequency of major stratospheric warmings (7 in the past 6 years) is unprecedented. Lower stratospheric temperatures were unusually high during 6 of the past 7 years, with 5 having much lower than usual potential for polar stratospheric cloud (PSC) formation and ozone loss (nearly none in 1998-1999, 2001-2002, and 2003-2004, and very little in 1997 1998 and 2000-2001). Middle and upper stratospheric temperatures, however, were unusually low during and after February. The pattern of 5 of the last 7 years with very low PSC potential would be expected to occur randomly once every similar to850 years. This cluster of warm winters, immediately following a period of unusually cold winters, may have important implications for possible changes in interannual variability and for determination and attribution of trends in stratospheric temperatures and ozone. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. New Mexico Highlands Univ, Dept Nat Sci, Las Vegas, NM 87701 USA. Free Univ Berlin, Inst Meteorol, D-1000 Berlin, Germany. Alfred Wegener Inst Polar & Marine Res, D-14401 Potsdam, Germany. New Mexico Highlands Univ, Sch Educ, Dept Comp & Math Sci, Las Vegas, NM USA. NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. RP Manney, GL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM manney@mls.jpl.nasa.gov RI Pawson, Steven/I-1865-2014 OI Pawson, Steven/0000-0003-0200-717X NR 58 TC 171 Z9 179 U1 3 U2 12 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 FEB 25 PY 2005 VL 110 IS D4 AR D04107 DI 10.1029/2004JD005367 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 904VM UT WOS:000227526200003 ER PT J AU Solomon, SC Aharonson, O Aurnou, JM Banerdt, WB Carr, MH Dombard, AJ Frey, HV Golombek, MP Hauck, SA Head, JW Jakosky, BM Johnson, CL McGovern, PJ Neumann, GA Phillips, RJ Smith, DE Zuber, MT AF Solomon, SC Aharonson, O Aurnou, JM Banerdt, WB Carr, MH Dombard, AJ Frey, HV Golombek, MP Hauck, SA Head, JW Jakosky, BM Johnson, CL McGovern, PJ Neumann, GA Phillips, RJ Smith, DE Zuber, MT TI New perspectives on ancient Mars SO SCIENCE LA English DT Review ID MARTIAN HYDROTHERMAL SYSTEMS; HF-W CHRONOMETRY; MAGNETIC-FIELD; THERMAL EVOLUTION; TERRESTRIAL PLANETS; GLOBAL DISTRIBUTION; NORTHERN PLAINS; CRUSTAL MAGNETIZATION; EARLY DIFFERENTIATION; MANTLE CONVECTION AB Mars was most active during its first billion years. The core, mantle, and crust formed within similar to50 million years of solar system formation. A magnetic dynamo in a convecting fluid core magnetized the crust, and the global field shielded a more massive early atmosphere against solar wind stripping. The Tharsis province became a focus for volcanism, deformation, and outgassing of water and carbon dioxide in quantities possibly sufficient to induce episodes of climate warming. Surficial and near-surface water contributed to regionally extensive erosion, sediment transport, and chemical alteration. Deep hydrothermal circulation accelerated crustal cooling, preserved variations in crustal thickness, and modified patterns of crustal magnetization. C1 Carnegie Inst Washington, Dept Terr Magnetism, Washington, DC 20015 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. US Geol Survey, Menlo Pk, CA 94025 USA. Washington Univ, Dept Earth & Planetary Sci, St Louis, MO 63130 USA. NASA, Terr Phys Lab, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Case Western Reserve Univ, Dept Geol Sci, Cleveland, OH 44106 USA. Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA. Univ Calif San Diego, Scripps Inst Oceanog, Inst Geophys & Planetary Phys, La Jolla, CA 92093 USA. Lunar & Planetary Inst, Houston, TX 77058 USA. MIT, Dept Earth Atmospher & Planetary Sci, Cambridge, MA 02139 USA. RP Solomon, SC (reprint author), Carnegie Inst Washington, Dept Terr Magnetism, 5241 Broad Branch Rd NW, Washington, DC 20015 USA. EM scs@dtm.ciw.edu RI Hauck, Steven/A-7865-2008; Neumann, Gregory/I-5591-2013 OI McGovern, Patrick/0000-0001-9647-3096; Hauck, Steven/0000-0001-8245-146X; Neumann, Gregory/0000-0003-0644-9944 NR 102 TC 175 Z9 179 U1 3 U2 41 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 FEB 25 PY 2005 VL 307 IS 5713 BP 1214 EP 1220 DI 10.1126/science.1101812 PG 7 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 901WP UT WOS:000227313200034 PM 15731435 ER PT J AU Porco, CC Baker, E Barbara, J Beurle, K Brahic, A Burns, JA Charnoz, S Cooper, N Dawson, DD Del Genio, AD Denk, T Dones, L Dyudina, U Evans, MW Giese, B Grazier, K Helfenstein, P Ingersoll, AP Jacobson, RA Johnson, TV McEwen, A Murray, CD Neukurn, G Owen, WM Perry, J Roatsch, T Spitale, J Squyres, S Thomas, P Tiscareno, M Turtle, E Vasavada, AR Veverka, J Wagner, R West, R AF Porco, CC Baker, E Barbara, J Beurle, K Brahic, A Burns, JA Charnoz, S Cooper, N Dawson, DD Del Genio, AD Denk, T Dones, L Dyudina, U Evans, MW Giese, B Grazier, K Helfenstein, P Ingersoll, AP Jacobson, RA Johnson, TV McEwen, A Murray, CD Neukurn, G Owen, WM Perry, J Roatsch, T Spitale, J Squyres, S Thomas, P Tiscareno, M Turtle, E Vasavada, AR Veverka, J Wagner, R West, R TI Cassini Imaging Science: Initial results on Saturn's rings and small satellites SO SCIENCE LA English DT Article ID F-RING; PLANETARY RINGS; STELLAR OCCULTATION; MAIN RINGS; VOYAGER OBSERVATIONS; IRREGULAR STRUCTURE; PARTICLE SIZES; DENSITY WAVES; ENCKE GAP; B-RING AB Images acquired of Saturn's rings and small moons by the Cassini Imaging Science Subsystem (ISS) during the first 9 months of Cassini operations at Saturn have produced many new findings. These include new saturnian moons; refined orbits of new and previously known moons; narrow diffuse rings in the F-ring region and embedded in gaps within the main rings; exceptionally fine-scale ring structure in moderate- to high-optical depth regions; new estimates for the masses of ring-region moons, as well as ring particle properties in the Cassini division, derived from the analysis of linear density waves; ring particle albedos in select ring regions; And never-before-seen phenomena within the rings. C1 Space Sci Inst, Cassini Imaging Cent Lab Operat, Boulder, CO 80301 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Queen Mary, Astron Unit, London E1 4NS, England. Univ Paris 07, Ctr Etud Saclay, F-91191 Gif Sur Yvette, France. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Free Univ Berlin, Inst Geol Wissensch, D-12249 Berlin, Germany. SW Res Inst, Dept Space Studies, Boulder, CO 80302 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. German Aerosp Ctr, Inst Planetary Res, D-12489 Berlin, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Porco, CC (reprint author), Space Sci Inst, Cassini Imaging Cent Lab Operat, 4750 Walnut St,Suite 205, Boulder, CO 80301 USA. EM carolyn@ciclops.org RI Tiscareno, Matthew/D-6963-2011; Del Genio, Anthony/D-4663-2012; Turtle, Elizabeth/K-8673-2012 OI Del Genio, Anthony/0000-0001-7450-1359; Turtle, Elizabeth/0000-0003-1423-5751 NR 70 TC 125 Z9 125 U1 0 U2 11 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD FEB 25 PY 2005 VL 307 IS 5713 BP 1226 EP 1236 DI 10.1126/science.1108056 PG 11 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 901WP UT WOS:000227313200038 PM 15731439 ER PT J AU Porco, CC Baker, E Barbara, J Beurle, K Brahic, A Burns, JA Charnoz, S Cooper, N Dawson, DD Del Genio, AD Denk, T Dones, L Dyudina, U Evans, MW Giese, B Grazier, K Heifenstein, P Ingersoll, AP Jacobson, RA Johnson, TV McEwen, A Murray, CD Neukum, G Owen, WM Perry, J Roatsch, T Spitale, J Squyres, S Thomas, PC Tiscareno, M Turtle, E Vasavada, AR Veverka, J Wagner, R West, R AF Porco, CC Baker, E Barbara, J Beurle, K Brahic, A Burns, JA Charnoz, S Cooper, N Dawson, DD Del Genio, AD Denk, T Dones, L Dyudina, U Evans, MW Giese, B Grazier, K Heifenstein, P Ingersoll, AP Jacobson, RA Johnson, TV McEwen, A Murray, CD Neukum, G Owen, WM Perry, J Roatsch, T Spitale, J Squyres, S Thomas, PC Tiscareno, M Turtle, E Vasavada, AR Veverka, J Wagner, R West, R TI Cassini Imaging Science: Initial results on Phoebe and Iapetus SO SCIENCE LA English DT Article ID DARK SIDE; IRREGULAR SATELLITES; EVOLUTION; ASTEROIDS; LAPETUS; ORIGIN AB The Cassini Imaging Science Subsystem acquired high-resolution imaging data on the outer Saturnian moon, Phoebe, during Cassini's close flyby on 11 June 2004 and on lapetus during a flyby on 31 December 2004. Phoebe has a heavily cratered and ancient surface, shows evidence of ice near the surface, has distinct layering of different materials, and has a mean density that is indicative of an ice-rock mixture. lapetus's dark leading side (Cassini Regio) is ancient, heavily cratered terrain bisected by an equatorial ridge system that reaches 20 kilometers relief. Local albedo variations within and bordering Cassini Regio suggest mass wasting of ballistically deposited material, the origin of which remains unknown. C1 Space Sci Inst, Cassini Imaging Cent Lab Operat, Boulder, CO 80301 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Univ London, Queen Mary, Astron Unit, London E1 4NS, England. Univ Paris 07, Ctr Etud Saclay, F-91191 Gif Sur Yvette, France. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Free Univ Berlin, Inst Geol Wissensch, D-12249 Berlin, Germany. SW Res Inst, Dept Space Sci, Boulder, CO 80302 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. German Aerosp Ctr, Inst Planetary Res, D-12489 Berlin, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Porco, CC (reprint author), Space Sci Inst, Cassini Imaging Cent Lab Operat, 4750 Walnut St,Suite 205, Boulder, CO 80301 USA. EM carotyn@ciclops.org RI Tiscareno, Matthew/D-6963-2011; Del Genio, Anthony/D-4663-2012; Turtle, Elizabeth/K-8673-2012 OI Del Genio, Anthony/0000-0001-7450-1359; Turtle, Elizabeth/0000-0003-1423-5751 NR 34 TC 103 Z9 103 U1 0 U2 8 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 FEB 25 PY 2005 VL 307 IS 5713 BP 1237 EP 1242 DI 10.1126/science.1107981 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 901WP UT WOS:000227313200039 PM 15731440 ER PT J AU Porco, CC Baker, E Barbara, J Beurle, K Brahic, A Burns, JA Charnoz, S Cooper, N Dawson, DD Del Genio, AD Denk, T Dones, L Dyudina, U Evans, MW Giese, B Grazier, K Heifenstein, P Ingersoll, AP Jacobson, RA Johnson, TV McEwen, A Murray, CD Neukum, G Owen, WM Perry, J Roatsch, T Spitale, J Squyres, S Thornas, P Tiscareno, M Turtle, E Vasavada, AR Veverka, J Wagner, R West, R AF Porco, CC Baker, E Barbara, J Beurle, K Brahic, A Burns, JA Charnoz, S Cooper, N Dawson, DD Del Genio, AD Denk, T Dones, L Dyudina, U Evans, MW Giese, B Grazier, K Heifenstein, P Ingersoll, AP Jacobson, RA Johnson, TV McEwen, A Murray, CD Neukum, G Owen, WM Perry, J Roatsch, T Spitale, J Squyres, S Thornas, P Tiscareno, M Turtle, E Vasavada, AR Veverka, J Wagner, R West, R TI Cassini Imaging Science: Initial results on Saturn's atmosphere SO SCIENCE LA English DT Article ID ZONAL WINDS; ELECTROSTATIC DISCHARGES; JUPITERS ATMOSPHERE; CLOUD LEVEL; MORPHOLOGY; MOTIONS AB The Cassini Imaging Science Subsystem (ISS) began observing Saturn in early February 2004. From analysis of cloud motions through early October 2004, we report vertical wind shear in Saturn's equatorial jet and a maximum wind speed of similar to375 meters per second, a value that differs from both Hubble Space Telescope and Voyager values. We also report a particularly active narrow southern mid-latitude region in which dark ovals are observed both to merge with each other and to arise from the eruptions of large, bright storms. Bright storm eruptions are correlated with Saturn's electrostatic discharges, which are thought to originate from lightning. C1 Space Sci Inst, Cassini Imaging Cent Lab Operat, Boulder, CO 80301 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Univ London, Queen Mary, Astron Unit, London E1 4NS, England. Univ Paris 07, Ctr Etud Saclay, F-91191 Gif Sur Yvette, France. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Univ Arizona, Dept Planetary Sci, Tucson, AZ 85721 USA. Free Univ Berlin, Inst Geol Wissensch, D-12249 Berlin, Germany. SW Res Inst, Dept Space Sci, Boulder, CO 80302 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. German Aerosp Ctr, Inst Planetary Res, D-12489 Berlin, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Porco, CC (reprint author), Space Sci Inst, Cassini Imaging Cent Lab Operat, 4750 Walnut St,Suite 205, Boulder, CO 80301 USA. EM carolyn@ciclops.org RI Tiscareno, Matthew/D-6963-2011; Del Genio, Anthony/D-4663-2012; Turtle, Elizabeth/K-8673-2012 OI Del Genio, Anthony/0000-0001-7450-1359; Turtle, Elizabeth/0000-0003-1423-5751 NR 20 TC 78 Z9 78 U1 4 U2 14 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD FEB 25 PY 2005 VL 307 IS 5713 BP 1243 EP 1247 DI 10.1126/science.1107691 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 901WP UT WOS:000227313200040 PM 15731441 ER PT J AU Flasar, FM Achterberg, RK Conrath, BJ Pearl, JC Bjoraker, GL Jennings, DE Romani, PN Simon-Miller, AA Kunde, VG Nixon, CA Bezard, B Orton, GS Spilker, LJ Spencer, JR Irwin, PGJ Teanby, NA Owen, TC Brasunas, J Segura, ME Carlson, RC Mamoutkine, A Gierasch, PJ Schinder, PJ Showaiter, MR Ferrari, C Barucci, A Courtin, R Coustenis, A Fouchet, T Gautier, D Lellouch, E Marten, A Prange, R Strobel, DF Calcutt, SB Read, PL Taylor, FW Bowles, N Samuelson, RE Abbas, MM Raulin, F Ade, P Edgington, S Pilorz, S Wallis, B Wishnow, EH AF Flasar, FM Achterberg, RK Conrath, BJ Pearl, JC Bjoraker, GL Jennings, DE Romani, PN Simon-Miller, AA Kunde, VG Nixon, CA Bezard, B Orton, GS Spilker, LJ Spencer, JR Irwin, PGJ Teanby, NA Owen, TC Brasunas, J Segura, ME Carlson, RC Mamoutkine, A Gierasch, PJ Schinder, PJ Showaiter, MR Ferrari, C Barucci, A Courtin, R Coustenis, A Fouchet, T Gautier, D Lellouch, E Marten, A Prange, R Strobel, DF Calcutt, SB Read, PL Taylor, FW Bowles, N Samuelson, RE Abbas, MM Raulin, F Ade, P Edgington, S Pilorz, S Wallis, B Wishnow, EH TI Temperatures, winds, and composition in the saturnian system SO SCIENCE LA English DT Article ID GALILEO PHOTOPOLARIMETER-RADIOMETER; VOYAGER INFRARED MEASUREMENTS; 1990 EQUATORIAL DISTURBANCE; GIANT PLANETS; CLOUD LEVEL; ZONAL WINDS; RINGS; STRATOSPHERE; ABUNDANCES; ATMOSPHERE AB Stratospheric temperatures on Saturn imply a strong decay of the equatorial winds with attitude. If the decrease in winds reported from recent Hubble Space Telescope images is not a temporal change, then the features tracked must have been at least 130 kilometers higher than in earlier studies. Saturn's south polar stratosphere is warmer than predicted from simple radiative models. The C/H ratio on Saturn is seven times solar, twice Jupiter's. Saturn's ring, temperatures have radial variations down to the smallest scale resolved (100 kilometers). Diurnal surface temperature variations on Phoebe suggest a more porous regolith than on the jovian satellites. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Observ Paris, CNRS, UMR 8109, LESIA, F-91925 Meudon, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. SW Res Inst, Dept Space Studies, Boulder, CO 80302 USA. Univ Oxford, Clarendon Lab, Oxford OX1 3PU, England. Univ Hawaii, Inst Astron, Honolulu, HI 96822 USA. QSS Grp Inc, Lanham, MD 20706 USA. NASA, Ames Res Ctr, Stanford Univ, Moffett Field, CA 94035 USA. CEA Saclay, Serv Astrophys, F-91191 Gif Sur Yvette, France. Johns Hopkins Univ, Dept Earth & Planetary Sci, Baltimore, MD 21218 USA. NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr SD50, Huntsville, AL 35812 USA. Univ Paris 07, LISA, F-94010 Creteil, France. Univ Paris 12, CNRS, UMR 7583, F-94010 Creteil, France. Univ Cardiff, Dept Phys & Astron, Cardiff CF24 3YB, S Glam, Wales. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Berkeley, Space Sci Lab, Livermore, CA 94551 USA. RP Flasar, FM (reprint author), NASA, Goddard Space Flight Ctr, Code 693, Greenbelt, MD 20771 USA. EM f.m.flasar@nasa.gov RI Nixon, Conor/A-8531-2009; Flasar, F Michael/C-8509-2012; Romani, Paul/D-2729-2012; Bjoraker, Gordon/D-5032-2012; Jennings, Donald/D-7978-2012; brasunas, john/I-2798-2013; Simon, Amy/C-8020-2012; Ferrari, Cecile/P-9735-2016; Fouchet, Thierry/C-6374-2017; OI Nixon, Conor/0000-0001-9540-9121; Simon, Amy/0000-0003-4641-6186; Ferrari, Cecile/0000-0001-5962-7439; Fouchet, Thierry/0000-0001-9040-8285; Teanby, Nicholas/0000-0003-3108-5775; Calcutt, Simon/0000-0002-0102-3170; Irwin, Patrick/0000-0002-6772-384X NR 29 TC 113 Z9 113 U1 0 U2 10 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 FEB 25 PY 2005 VL 307 IS 5713 BP 1247 EP 1251 DI 10.1126/science.1105806 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 901WP UT WOS:000227313200041 PM 15618486 ER PT J AU Esposito, LW Colwell, JE Larsen, K McClintock, WE Stewart, AIF Hallett, JT Shemansky, DE Ajello, JM Hansen, CJ Hendrix, AR West, RA Keller, HU Korth, A Pryor, WR Reulke, R Yung, YL AF Esposito, LW Colwell, JE Larsen, K McClintock, WE Stewart, AIF Hallett, JT Shemansky, DE Ajello, JM Hansen, CJ Hendrix, AR West, RA Keller, HU Korth, A Pryor, WR Reulke, R Yung, YL TI Ultraviolet Imaging Spectroscopy shows an active saturnian system SO SCIENCE LA English DT Article ID SPACE-TELESCOPE; GAS-DRAG; E-RING; MAGNETOSPHERE; ENCOUNTER; SATELLITE; ACCRETION; EVOLUTION; EMISSION; HYDROGEN AB Neutral oxygen in the Saturnian system shows variability, and the total number of oxygen atoms peaks at 4 x 10(34). Saturn's aurora brightens in response to solar-wind forcing, and the auroral spectrum resembles Jupiter's. Phoebe's surface shows variabie water-ice content, and the data indicate it originated in the outer solar system. Saturn's rings also show variable water abundance, with the purest ice in the outermost A ring. This radial variation is consistent with initially pure water ice bombarded by meteors, but smaller radial structures may indicate collisional transport and recent renewal events in the past 10(7) to 10(8) years. C1 Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80303 USA. Univ So Calif, Los Angeles, CA 90089 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Max Planck Inst Sonnensyst Forsch, D-37191 Katlenburg Lindau, Germany. Cent Arizona Coll, Coolidge, AZ 85228 USA. Univ Stuttgart, Inst Photogrammetry, D-70174 Stuttgart, Germany. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RP Esposito, LW (reprint author), Univ Colorado, Atmospher & Space Phys Lab, 234 Innovat Dr, Boulder, CO 80303 USA. EM larry.esposito@lasp.colorado.edu NR 33 TC 95 Z9 95 U1 0 U2 8 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 FEB 25 PY 2005 VL 307 IS 5713 BP 1251 EP 1255 DI 10.1126/science.1105606 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 901WP UT WOS:000227313200042 PM 15604361 ER PT J AU Gurnett, DA Kurth, WS Hospodarsky, GB Persoon, AM Averkamp, TF Cecconi, B Lecacheux, A Zarka, P Canu, P Cornilleau-Wehrlin, N Galopeau, P Roux, A Harvey, C Louarn, P Bostrom, R Gustafsson, G Wahlund, JE Desch, MD Farrell, WM Kaiser, ML Goetz, K Kellogg, PJ Fischer, G Ladreiter, HP Rucker, H Alleyne, H Pedersen, A AF Gurnett, DA Kurth, WS Hospodarsky, GB Persoon, AM Averkamp, TF Cecconi, B Lecacheux, A Zarka, P Canu, P Cornilleau-Wehrlin, N Galopeau, P Roux, A Harvey, C Louarn, P Bostrom, R Gustafsson, G Wahlund, JE Desch, MD Farrell, WM Kaiser, ML Goetz, K Kellogg, PJ Fischer, G Ladreiter, HP Rucker, H Alleyne, H Pedersen, A TI Radio and plasma wave observations at Saturn from Cassini's approach and first orbit SO SCIENCE LA English DT Article ID ELECTROSTATIC DISCHARGES; ASTRONOMY OBSERVATIONS; VOYAGER-2; ROTATION; IMPACTS AB We report data from the Cassini radio and plasma wave instrument during the approach and first orbit at Saturn. During the approach, radio emissions from Saturn showed that the radio rotation period is now 10 hours 45 minutes 45 +/- 36 seconds, about 6 minutes longer than measured by Voyager in 1980 to 1981. In addition, many intense impulsive radio signals were detected from Saturn lightning during the approach and first orbit. Some of these have been linked to storm systems observed by the Cassini imaging instrument. Within the magnetosphere, whistler-mode aurora[ hiss emissions were observed near the rings, suggesting that a strong electrodynamic interaction is occurring in or near the rings. C1 Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Observ Paris, F-92195 Meudon, France. CETP, Inst Pierre Simon La Pl, F-78140 Velizy Villacoublay, France. Ctr Etud Spatiale Rayonnements, CNRS, F-31028 Toulouse, France. Swedish Inst Space Phys, SE-75121 Uppsala, Sweden. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Minnesota, Dept Phys & Astron, Minneapolis, MN 55455 USA. Austrian Acad Sci, Space Res Inst, A-8042 Graz, Austria. Univ Sheffield, Dept Automat Control & Syst Engn, Sheffield S1 4DU, S Yorkshire, England. Univ Oslo, Dept Phys, N-0316 Oslo, Norway. RP Gurnett, DA (reprint author), Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. EM donald-gurnett@uiowa.edu RI Farrell, William/I-4865-2013 NR 30 TC 162 Z9 162 U1 0 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD FEB 25 PY 2005 VL 307 IS 5713 BP 1255 EP 1259 DI 10.1126/science.1105356 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 901WP UT WOS:000227313200043 PM 15604362 ER PT J AU Waite, JH Cravens, TE Ip, WH Kasprzak, WT Luhmann, JG McNutt, RL Niemann, HB Yelle, RV Mueller-Wodarg, I Ledvina, SA Scherer, S AF Waite, JH Cravens, TE Ip, WH Kasprzak, WT Luhmann, JG McNutt, RL Niemann, HB Yelle, RV Mueller-Wodarg, I Ledvina, SA Scherer, S TI Oxygen ions observed near Saturn's A ring SO SCIENCE LA English DT Article AB Ions were detected in the vicinity of Saturn's A ring by the Ion and Neutral Mass Spectrometer (INMS) instrument onboard the Cassini Orbiter during the spacecraft's passage over the rings. The INMS saw signatures of molecular and atomic oxygen ions and of protons, thus demonstrating the existence of an ionosphere associated with the A ring. A likely explanation for these ions is photoionization by solar ultraviolet radiation of neutral O-2 molecules associated with a tenuous ring atmosphere. INMS neutral measurements made during the ring encounter are dominated by a background signal. C1 Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. Natl Cent Univ, Inst Astron, Chungli 32054, Taiwan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Arizona, Lunar & Planetary Lab, Tucson, AZ 85721 USA. Univ London Imperial Coll Sci Technol & Med, Space & Atmospher Phys Grp, London SW7 2BW, England. RP Cravens, TE (reprint author), Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. EM cravens@ku.edu RI McNutt, Ralph/E-8006-2010; Mueller-Wodarg, Ingo/M-9945-2014 OI McNutt, Ralph/0000-0002-4722-9166; Mueller-Wodarg, Ingo/0000-0001-6308-7826 NR 16 TC 47 Z9 47 U1 0 U2 6 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 FEB 25 PY 2005 VL 307 IS 5713 BP 1260 EP 1262 DI 10.1126/science.1105734 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 901WP UT WOS:000227313200044 PM 15731442 ER PT J AU Young, DT Berthelier, JJ Blanc, M Burch, JL Bolton, S Coates, AJ Crary, FJ Goldstein, R Grande, M Hill, TW Johnson, RE Baragiola, RA Kelha, V McComas, DJ Mursula, K Sittler, EC Svenes, KR Szego, K Tanskanen, P Thomsen, MF Bakshi, S Barraclough, BL Bebesi, Z Delapp, D Dunlop, MW Gosling, JT Furman, JD Gilbert, LK Glenn, D Holmlund, C Illiano, JM Lewis, GR Linder, DR Maurice, S McAndrews, HJ Narheim, BT Pallier, E Reisenfeld, D Rymer, AM Smith, HT Tokar, RL Vilppola, J Zinsmeyer, C AF Young, DT Berthelier, JJ Blanc, M Burch, JL Bolton, S Coates, AJ Crary, FJ Goldstein, R Grande, M Hill, TW Johnson, RE Baragiola, RA Kelha, V McComas, DJ Mursula, K Sittler, EC Svenes, KR Szego, K Tanskanen, P Thomsen, MF Bakshi, S Barraclough, BL Bebesi, Z Delapp, D Dunlop, MW Gosling, JT Furman, JD Gilbert, LK Glenn, D Holmlund, C Illiano, JM Lewis, GR Linder, DR Maurice, S McAndrews, HJ Narheim, BT Pallier, E Reisenfeld, D Rymer, AM Smith, HT Tokar, RL Vilppola, J Zinsmeyer, C TI Composition and dynamics of plasma in Saturn's magnetosphere SO SCIENCE LA English DT Article ID WATER ICE; MODEL; INJECTIONS; VOYAGER-2; TRANSPORT; ORBIT AB During Cassini's initial orbit, we observed a dynamic magnetosphere composed primarily of a complex mixture of water-derived atomic and molecular ions. We have identified four distinct regions characterized by differences in both bulk plasma properties and ion composition. Protons are the dominant species outside about 9 R(s) (where R(s) is the radial distance from the center of Saturn), whereas inside, the plasma consists primarily of a corotating comet-like mix of water-derived ions with similar to3% N+. Over the A and B rings, we found an ionosphere in which O(2)(+) and O(+) are dominant, which suggests the possible existence of a layer of O(2). gas similar to the atmospheres of Europa and Ganymede. C1 SW Res Inst, San Antonio, TX 78238 USA. Observ St Maur, Ctr Etud Environm Terr & Planetaires, F-94107 St Maur, France. Observ Midi Pyrenees, F-31400 Toulouse, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Rice Univ, Dept Phys & Astron, Houston, TX 77251 USA. Univ Virginia, Charlottesville, VA USA. Univ Oulu, Dept Phys Sci, Oulu 90014, Finland. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Norwegian Def Res Estab, Div Elect, N-2027 Kjeller, Norway. KFKI Res Inst Particle & Nucl Phys, H-1525 Budapest, Hungary. Los Alamos Natl Lab, Space & Atmospher Sci Grp, Los Alamos, NM 87545 USA. Univ Montana, Dept Phys & Astron, Missoula, MT 59812 USA. RP Young, DT (reprint author), SW Res Inst, San Antonio, TX 78238 USA. EM dyoung@swri.edu RI Coates, Andrew/C-2396-2008; Mursula, Kalevi/L-8952-2014; Reisenfeld, Daniel/F-7614-2015; Smith, Howard/H-4662-2016; Grande, Manuel/C-2242-2013 OI Coates, Andrew/0000-0002-6185-3125; Mursula, Kalevi/0000-0003-4892-5056; Smith, Howard/0000-0003-3537-3360; Grande, Manuel/0000-0002-2233-2618 NR 36 TC 209 Z9 209 U1 3 U2 14 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 FEB 25 PY 2005 VL 307 IS 5713 BP 1262 EP 1266 DI 10.1126/science.1106151 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 901WP UT WOS:000227313200045 PM 15731443 ER PT J AU Dougherty, MK Achilleos, N Andre, N Arridge, CS Balogh, A Bertucci, C Burton, ME Cowley, SWH Erdos, G Giampieri, G Glassmeier, KH Khurana, KK Leisner, J Neubauer, FM Russell, CT Smith, EJ Southwood, DJ Tsurutani, BT AF Dougherty, MK Achilleos, N Andre, N Arridge, CS Balogh, A Bertucci, C Burton, ME Cowley, SWH Erdos, G Giampieri, G Glassmeier, KH Khurana, KK Leisner, J Neubauer, FM Russell, CT Smith, EJ Southwood, DJ Tsurutani, BT TI Cassini magnetometer observations during Saturn orbit insertion SO SCIENCE LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; SOLAR-WIND; BOW SHOCKS; MAGNETOSPHERE; MODEL; MAGNETOPAUSE; WAVES AB Cassini's successful orbit insertion has provided the first examination of Saturn's magnetosphere in 23 years, revealing a dynamic plasma and magnetic environment on short and long time scales. There has been no noticeable change in the internal magnetic field, either in its strength or its near-alignment with the rotation axis. However, the external magnetic field is different compared with past spacecraft observations. The current sheet within the magnetosphere is thinner and more extended, and we observed small diamagnetic cavities and ion cyclotron waves of types that were not reported before. C1 Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2AZ, England. CESR, F-31028 Toulouse, France. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. KFKI Res Inst Particle & Nucl Phys, H-1525 Budapest, Hungary. Tech Univ Carolo Wilhelmina Braunschweig, D-38106 Braunschweig, Germany. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. Univ Cologne, Inst Geophys & Meteorol, D-50923 Cologne, Germany. European Space Agcy, F-75738 Paris, France. RP Dougherty, MK (reprint author), Univ London Imperial Coll Sci Technol & Med, Blackett Lab, Prince Consort Rd, London SW7 2AZ, England. EM m.dougherty@imperial.ac.uk RI Achilleos, Nicholas/C-1647-2008; Arridge, Christopher/A-2894-2009; OI Arridge, Christopher/0000-0002-0431-6526; Bertucci, Cesar/0000-0002-2540-5384; Achilleos, Nicholas/0000-0002-5886-3509 NR 20 TC 161 Z9 161 U1 0 U2 11 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD FEB 25 PY 2005 VL 307 IS 5713 BP 1266 EP 1270 DI 10.1126/science.1106098 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 901WP UT WOS:000227313200046 PM 15731444 ER PT J AU Krimigis, SM Mitchell, DG Hamilton, DC Krupp, N Livi, S Roelof, EC Dandouras, J Armstrong, TP Mauk, BH Paranicas, C Brandt, PC Bolton, S Cheng, AF Choo, T Gloeckler, G Hayes, J Hsieh, KC Ip, WH Jaskulek, S Keath, EP Kirsch, E Kusterer, M Lagg, A Lanzerotti, LJ LaVallee, D Manweiler, J McEntire, RW Rasmuss, W Saur, J Turner, FS Williams, DJ Woch, J AF Krimigis, SM Mitchell, DG Hamilton, DC Krupp, N Livi, S Roelof, EC Dandouras, J Armstrong, TP Mauk, BH Paranicas, C Brandt, PC Bolton, S Cheng, AF Choo, T Gloeckler, G Hayes, J Hsieh, KC Ip, WH Jaskulek, S Keath, EP Kirsch, E Kusterer, M Lagg, A Lanzerotti, LJ LaVallee, D Manweiler, J McEntire, RW Rasmuss, W Saur, J Turner, FS Williams, DJ Woch, J TI Dynamics of Saturn's magnetosphere from MIMI during Cassini's orbital insertion SO SCIENCE LA English DT Article ID ENERGETIC NEUTRAL ATOMS; HOT PLASMA; PARTICLES; INNER; GAS AB The Magnetospheric Imaging Instrument (MIMI) onboard the Cassini spacecraft observed the saturnian magnetosphere from January 2004 until Saturn orbit insertion (Sol) on 1 July 2004. The MIMI sensors observed frequent energetic particle activity in interplanetary space for several months before Sol. When the imaging sensor was switched to its energetic neutral atom (ENA) operating mode on 20 February 2004, at similar to10(3) times Saturn's radius R-s (0.43 astronomical units), a weak but persistent signal was observed from the magnetosphere. About 10 days before Sol, the magnetosphere exhibited a day-night asymmetry that varied with an similar to 11-hour periodicity. Once Cassini entered the magnetosphere, in situ measurements showed high concentrations of H+, H-2(+), O+, OH+, and H2O+ and low concentrations of N+. The radial dependence of ion intensity profiles implies neutral gas densities sufficient to produce high loss rates of trapped ions from the middle and inner magnetosphere. ENA imaging has revealed a radiation belt that resides inward of the D ring and is probably the result of double charge exchange between the main radiation belt and the upper layers of Saturn's exosphere. C1 Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Max Planck Inst Sonnensyst Forsch, D-37191 Lindau, Germany. Ctr Etud Spatiale Rayonnements, F-31028 Toulouse, France. Fundamental Technol Inc, Lawrence, KS 66049 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. Natl Cent Univ, Grad Inst Astron, Jhongli City, Peoples R China. Bell Labs, Murray Hill, NJ 07974 USA. New Jersey Inst Technol, Newark, NJ 07102 USA. RP Krimigis, SM (reprint author), Johns Hopkins Univ, Appl Phys Lab, Johns Hopkins Rd, Laurel, MD 20723 USA. EM tom.krimigis@jhuapl.edu RI Paranicas, Christopher/B-1470-2016; Brandt, Pontus/N-1218-2016; Mauk, Barry/E-8420-2017; OI Paranicas, Christopher/0000-0002-4391-8255; Brandt, Pontus/0000-0002-4644-0306; Mauk, Barry/0000-0001-9789-3797; Dandouras, Iannis/0000-0002-7121-1118; Hamilton, Douglas/0000-0001-6103-8019 NR 20 TC 120 Z9 120 U1 2 U2 12 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 FEB 25 PY 2005 VL 307 IS 5713 BP 1270 EP 1273 DI 10.1126/science.1105978 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 901WP UT WOS:000227313200047 PM 15731445 ER PT J AU Kempf, S Srama, R Postberg, F Burton, M Green, SF Helfert, S Hillier, JK McBride, N McDonnell, JAM Moragas-Klostermeyer, G Roy, M Grun, E AF Kempf, S Srama, R Postberg, F Burton, M Green, SF Helfert, S Hillier, JK McBride, N McDonnell, JAM Moragas-Klostermeyer, G Roy, M Grun, E TI Composition of saturnian stream particles SO SCIENCE LA English DT Article ID DUST; JUPITER AB During Cassini's approach to Saturn, the Cosmic Dust Analyser (CDA) discovered streams of tiny (less than 20 nanometers) high-velocity (similar to100 kilometers per second) dust particles escaping from the saturnian system. A fraction of these impactors originated from the outskirts of Saturn's dense A ring. The CDA time-of-flight mass spectrometer recorded 584 mass spectra from the stream particles. The particles consist predominantly of oxygen, silicon, and iron, with some evidence of water ice, ammonium, and perhaps carbon. The stream particles primarily consist, of silicate materials, and this implies that the particles are impurities from the icy ring material rather than the ice particles themselves. C1 Max Planck Inst Kernphys, D-69117 Heidelberg, Germany. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Open Univ, Planetary & Space Sci Res Inst, Milton Keynes MK7 6AA, Bucks, England. Univ Hawaii, Hawaii Inst Geophys & Planetol, Honolulu, HI 96822 USA. RP Kempf, S (reprint author), Max Planck Inst Kernphys, Saupfercheckweg 1, D-69117 Heidelberg, Germany. EM Sascha.Kempf@mpi-hd.mpg.de RI Green, Simon/C-7408-2009; OI KEMPF, SASCHA/0000-0001-5236-3004 NR 14 TC 55 Z9 55 U1 2 U2 10 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 FEB 25 PY 2005 VL 307 IS 5713 BP 1274 EP 1276 DI 10.1126/science.1106218 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 901WP UT WOS:000227313200048 PM 15731446 ER PT J AU Mori, H Iizuka, R Shibata, R Haba, Y Hayakawa, A Hayashi, A Inoue, C Inoue, H Ishida, M Itoh, A Itoh, K Kunieda, H Maeda, Y Misaki, K Naitou, M Okada, S Shimizu, T Yokoyama, Y AF Mori, H Iizuka, R Shibata, R Haba, Y Hayakawa, A Hayashi, A Inoue, C Inoue, H Ishida, M Itoh, A Itoh, K Kunieda, H Maeda, Y Misaki, K Naitou, M Okada, S Shimizu, T Yokoyama, Y TI Pre-collimator of the Astro-E2 X-ray telescopes for stray-light reduction SO PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN LA English DT Article DE instrumentation : high angular resolution; techniques : high angular resolution; telescopes ID CALIBRATION; FABRICATION; PROTECTION; MISSION; MIRRORS; DESIGN; ASCA AB We present the design and fabrication of the pre-collimator for the X-ray telescope onboard the X-ray astronomy satellite Astro-E2, and its effect on stray-light reduction. The pre-collimator was designed to efficiently reduce secondary reflection, which is the brightest component of stray light, giving rise to a ghost image in the field of view of the focal-plane detector. With the pre-collimator, composed of blades with an effective height of 30 mm, we confirmed from X-ray measurements that the intensity of the secondary reflection is reduced by roughly a few orders of magnitude on average in the off-axis angle range of 20'-70'. We also confirmed that the loss of the on-axis effective area due to installation of the pre-collimator is only 0.5 +/- 0.2%. The field of view becomes narrower, but the reduction factor amounts only to 8%. Ray-tracing simulations of in-flight observations also demonstrate that introduction of the pre-collimator is expected to be highly significant for improving data quality, due to a reduction of secondary reflection. C1 Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Dept High Energy Astrophys, Sagamihara, Kanagawa 2298510, Japan. Nagoya Univ, Dept Phys, Chikusa Ku, Nagoya, Aichi 4648602, Japan. Tokyo Metropolitan Univ, Dept Phys, Hachioji, Tokyo 1920397, Japan. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Japan Aerosp Explorat Agcy, Inst Space & Astronaut Sci, Dept High Energy Astrophys, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 2298510, Japan. EM mori@astro.isas.jaxa.jp RI XRAY, SUZAKU/A-1808-2009 NR 13 TC 18 Z9 18 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0004-6264 EI 2053-051X J9 PUBL ASTRON SOC JPN JI Publ. Astron. Soc. Jpn. PD FEB 25 PY 2005 VL 57 IS 1 BP 245 EP 257 DI 10.1093/pasj/57.1.245 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 933IR UT WOS:000229622600022 ER PT J AU Fraser, BJ Horwitz, JL Slavin, JA Dent, ZC Mann, IR AF Fraser, BJ Horwitz, JL Slavin, JA Dent, ZC Mann, IR TI Heavy ion mass loading of the geomagnetic field near the plasmapause and ULF wave implications SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OUTER PLASMASPHERE; MAGNETOMETER NETWORK; DENSITY; MAGNETOSPHERE; PULSATIONS; LATITUDE; DYNAMICS; PERIODS; REGION AB [1] The structure of the density discontinuity across the plasmapause is often based on electron and H+ density profiles with the contribution of heavy ions ( He+, O+ etc) neglected. Electron and ion density measurements in this region may differ significantly due to the presence of heavy ions and it is important for the intercomparison of different datasets to understand these differences. Dynamics Explorer (DE-1) magnetic field and plasma composition data have been used to compare heavy ion responses across the plasmapause and to calculate the mass loaded ion density (p) profiles. To illustrate this we investigate mass loading through radial profile variations in the Alfven velocity ( V-A). Results show that the gradient in p and V-A across the plasmapause is modified when mass loading due to multiple heavy ion species is included, particularly in the presence of the O+ torus. Application to ultra-low frequency (ULF) field line resonance is used as an example where the contribution from heavy ions smoothes out the expected ULF wave resonant frequency discontinuity at the plasmapause. C1 Univ Newcastle, CRC Satellite Syst Math & Phys Sci, Newcastle, NSW 2308, Australia. Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. Univ Texas, Dept Phys, Arlington, TX 76019 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Fraser, BJ (reprint author), Univ Newcastle, CRC Satellite Syst Math & Phys Sci, Newcastle, NSW 2308, Australia. EM brian.fraser@newcastle.edu.au; horwitzj@uta.edu; jim.slavin@gsfc.nasa.gov; zdent@phys.ualberta.ca; imann@space.ualberta.ca RI Slavin, James/H-3170-2012 OI Slavin, James/0000-0002-9206-724X NR 26 TC 52 Z9 52 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 24 PY 2005 VL 32 IS 4 AR L04102 DI 10.1029/2004GL021315 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 904VD UT WOS:000227525300001 ER PT J AU Prigent, C Defer, E Pardo, JR Pearl, C Rossow, WB Pinty, JP AF Prigent, C Defer, E Pardo, JR Pearl, C Rossow, WB Pinty, JP TI Relations of polarized scattering signatures observed by the TRMM Microwave Instrument with electrical processes in cloud systems SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OPTICAL TRANSIENT DETECTOR; RADAR OBSERVATIONS; RADIATIVE-TRANSFER; TROPICAL RAINFALL; ICE-SCATTERING; PART I; SENSOR; THUNDERSTORMS; PARTICLES; CRYSTALS AB [1] The polarized scattering signatures observed in convective cloud systems with the Tropical Rainfall Measuring Mission (TRMM) Microwave Instrument are analyzed. In particular, and in contrast to the positive polarization difference (TbV-TbH > 0) observed when scattering by large ice particles is important, we also find a negative polarization difference. Radiative transfer simulations show that such a polarization difference can be explained by relatively large, mostly vertically oriented, nonspherical particles but not by horizontally or randomly oriented non-spherical particles. We establish a relationship between the occurrence of the negative polarization difference signature and electrical activity in the cloud using coincident observations by the Lightning Imaging Sensor also on board TRMM. The negative polarization difference is thus related to non-spherical particles that are mostly vertically oriented as revealed by the lightning activity. This result confirms that a careful analysis of passive microwave observations over clouds provides valuable information about the cloud ice phase. C1 Observ Paris, CNRS, Lab Etud Rayonnement & Mat Astrophys, F-75014 Paris, France. Lab Aerol, Toulouse, France. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. CSIC, Dept Astrofis Mol & Infrorroja, Inst Estructura Mat, E-28006 Madrid, Spain. Natl Observ Athens, Inst Environm Res, GR-11810 Athens, Greece. RP Prigent, C (reprint author), Observ Paris, CNRS, Lab Etud Rayonnement & Mat Astrophys, 61 Ave Observ, F-75014 Paris, France. EM catherine.prigent@obspm.fr RI Rossow, William/F-3138-2015 NR 19 TC 26 Z9 26 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 FEB 24 PY 2005 VL 32 IS 4 AR L04810 DI 10.1029/2004GL022225 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 904VD UT WOS:000227525300007 ER PT J AU Torres, O Bhartia, PK Sinyuk, A Welton, EJ Holben, B AF Torres, O Bhartia, PK Sinyuk, A Welton, EJ Holben, B TI Total Ozone Mapping Spectrometer measurements of aerosol absorption from space: Comparison to SAFARI 2000 ground-based observations SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SINGLE SCATTERING ALBEDO; SUN PHOTOMETER MEASUREMENTS; SKY RADIANCE MEASUREMENTS; OPTICAL-PROPERTIES; LIGHT-ABSORPTION; SAHARAN DUST; SATELLITE MEASUREMENTS; SURFACE REFLECTIVITY; RADIATIVE PROPERTIES; REFRACTIVE-INDEX AB The capability to detect the presence of absorbing aerosols in the atmosphere using space- based near- UV observations has been demonstrated in the last few years, as indicated by the widespread use by the atmospheric sciences community of the Total Ozone Mapping Spectrometer ( TOMS) aerosol index as a qualitative representation of aerosol absorption. An inversion procedure has been developed to convert the unique spectral signature generated by the interaction of molecular scattering and particle absorption into a quantitative measure of aerosol absorption. In this work we evaluate the accuracy of the near- UV method of aerosol absorption sensing by means of a comparison of TOMS retrieved aerosol single scattering albedo and extinction optical depth to groundbased measurements of the same parameters by the Aerosol Robotic Network ( AERONET) for a 2- month period during the SAFARI 2000 campaign. The availability of collocated AERONET observations of aerosol properties, as well as Micropulse Lidar Network measurements of the aerosol vertical distribution, offered a rare opportunity for the evaluation of the uncertainty associated with the height of the absorbing aerosol layer in the TOMS aerosol retrieval algorithm. Results of the comparative analysis indicate that in the absence of explicit information on the vertical distribution of the aerosols, the standard TOMS algorithm assumption yields, in most cases, reasonable agreement of aerosol optical depth ( +/-30%) and single scattering albedo ( +/-0.03) with the AERONET observations. When information on the aerosol vertical distribution is available, the accuracy of the retrieved parameters improves significantly in those cases when the actual aerosol profile is markedly different from the idealized algorithmic assumption. C1 Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD USA. RP Torres, O (reprint author), Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA. EM torres@tparty.gsfc.nasa.gov RI Welton, Ellsworth/A-8362-2012; Torres, Omar/G-4929-2013; Bhartia, Pawan/A-4209-2016 OI Bhartia, Pawan/0000-0001-8307-9137 NR 47 TC 48 Z9 48 U1 0 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 FEB 24 PY 2005 VL 110 IS D10 AR D10S18 DI 10.1029/JD004611 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 904VR UT WOS:000227526700001 ER PT J AU Wang, MH Knobelspiesse, KD McClain, CR AF Wang, MH Knobelspiesse, KD McClain, CR TI Study of the Sea-Viewing Wide Field-of-View Sensor (SeaWiFS) aerosol optical property data over ocean in combination with the ocean color products SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WATER-LEAVING RADIANCE; ATMOSPHERIC CORRECTION; IMAGING SPECTRORADIOMETER; ANTHROPOGENIC AEROSOLS; TROPOSPHERIC AEROSOLS; SPECTRAL REFLECTANCE; SURFACE-ROUGHNESS; SUN PHOTOMETER; SAHARAN DUST; AVHRR DATA AB The primary goals of the Sea- Viewing Wide Field- of- View Sensor ( SeaWiFS) are to routinely provide the global ocean color and ocean bio- optical property data. In retrieving the ocean near- surface signals from SeaWiFS- measured radiances, however, the aerosol effects must be accurately estimated and removed. Therefore SeaWiFS also produces the aerosol optical property data ( in particular, the aerosol optical thickness and Angstromngstrom exponent) over global ocean. Since September of 1997, SeaWiFS has generated both global aerosol ( over ocean) and ocean color data for more than 6.5 years and is still in producing these products with very good sensor performance. This makes SeaWiFS the longest in history for providing simultaneously the global aerosol and ocean color products. In this paper we describe the SeaWiFS aerosol products over ocean in combination with the ocean color data. We assert through various examples that, because SeaWiFS simultaneously retrieves both atmospheric and ocean color data, the SeaWiFS products are useful to study aerosol and ocean variations in climatic forcing, biogeochemical cycling, and radiative effects in the global and regional scales. C1 Sci Syst & Applicat Inc, NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. Univ Maryland Baltimore Cty, NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. RP Wang, MH (reprint author), NOAA, Natl Environm Satellite, Data & Informat Serv, Off Res & Applicat, E RA3,Room 102,5200 Auth Rd, Camp Springs, MD 20746 USA. EM menghua.wang@noaa.gov RI Wang, Menghua/F-5631-2010; Knobelspiesse, Kirk/S-5902-2016 OI Wang, Menghua/0000-0001-7019-3125; Knobelspiesse, Kirk/0000-0001-5986-1751 NR 70 TC 67 Z9 68 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 FEB 24 PY 2005 VL 110 IS D10 AR D10S06 DI 10.1029/2004JD004950 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 904VR UT WOS:000227526700002 ER PT J AU Bennett, ER Youngson, JH Jackson, JA Norris, RJ Raisbeck, GM Yiou, F Fielding, E AF Bennett, ER Youngson, JH Jackson, JA Norris, RJ Raisbeck, GM Yiou, F Fielding, E TI Growth of South Rough Ridge, Central Otago, New Zealand: Using in situ cosmogenic isotopes and geomorphology to study an active, blind reverse fault SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID AMS FACILITY; BE-10; EROSION; RATES; AL-26; MOUNTAINS; LANDSCAPE; EXPOSURE; SYSTEMS AB [1] In situ cosmogenic Be-10 and Al-26 measurements on sedimentary quartzites, together with analysis of abandoned river terraces, can be used to show how drainage responded to the lateral propagation of a late Quaternary anticline forming above a blind reverse fault in Central Otago, New Zealand. A close link between the progression of cosmogenic ages and the tectonic geomorphology allows us to confirm that uplift and propagation rates on the anticline are in the ranges 0.08 - 0.12 mm yr(-1) and 0.8 - 1.5 mm yr(-1), respectively, over the last 550,000 years. The agreement between the isotopic and geomorphological evidence in turn requires that minimum Be-10 exposure ages as great as 660 ka are not in steady state with respect to erosion. This is a geochemical result of significance, as it opens the possibility of a more regional analysis of landscape evolution in this region, using the same rocks. On an adjacent anticline, thought to be even older on geomorphological arguments, Be-10 concentrations give minimum exposure ages in the range 750 - 1400 ka. These extremely old minimum ages are rare worldwide, as they are usually limited to smaller values by erosion. They are attributable to the very resistant nature of the quartz-rich boulders in which the measurements were made, which in places are shown to have erosion rates lower than 0.5 mm kyr(-1). C1 Univ Cambridge, Dept Earth Sci, Bullard Labs, Cambridge CB3 0EZ, England. Univ Otago, Dept Geol, Dunedin, New Zealand. CNRS, IN2P3, Ctr Spectrometrie Nucl & Spectrometrie Masse, F-91405 Orsay, France. Jet Prop Lab, Pasadena, CA USA. RP Bennett, ER (reprint author), Univ Cambridge, Dept Earth Sci, Bullard Labs, Madingley Rd, Cambridge CB3 0EZ, England. EM bennett@esc.cam.ac.uk RI NCEO, COMET+`/A-3443-2013; Fielding, Eric/A-1288-2007 OI Fielding, Eric/0000-0002-6648-8067 NR 21 TC 22 Z9 22 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD FEB 24 PY 2005 VL 110 IS B2 AR B02404 DI 10.1029/2004JB003184 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 904WA UT WOS:000227527600004 ER PT J AU Curtis, DB Glandorf, DL Toon, OB Tolbert, MA McKay, CP Khare, BN AF Curtis, DB Glandorf, DL Toon, OB Tolbert, MA McKay, CP Khare, BN TI Laboratory studies of butane nucleation on organic haze particles: Application to Titan's clouds SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID PHOTOCHEMICAL FORMATION; LOWER ATMOSPHERE; X-RAY; AEROSOLS; THOLINS; CHEMISTRY; METHANE; CYANOACETYLENE; TEMPERATURE; TROPOSPHERE AB Titan, Saturn's largest satellite, has a thick nitrogen/methane atmosphere with various hydrocarbons present in minor amounts. Recent observations suggest that CH4 may condense to form clouds near the moon's tropopause. Titan's methane cloud formation is probably triggered by a sequential nucleation of hydrocarbons onto Titan's haze material as tropospheric convection occurs due to differential heating of the surface or as the haze settles through the lower stratosphere. To better constrain Titan's cloud formation mechanism, investigations of the nucleation of several hydrocarbons will be necessary. Butane was chosen for this study because it has a relatively high freezing point and is estimated to be present at 200 part per billion levels. If this amount of butane were to condense on each haze particle, a visible cloud would be observed. Laboratory measurements at T = 125 K were performed to determine the relative ease of solid butane nucleation onto laboratory-produced tholin particles having an elemental composition of C5H5N, and solid films of hexane and acetonitrile. We find that butane nucleation onto the haze particles requires a relatively high saturation ratio of S > 1.30. Because butane nucleation is difficult, it may occur on only a very small subset of the total haze particles available. Such selective nucleation of butane would lead to those particles becoming coated with significant amounts of butane. Requiring a high saturation ratio for butane nucleation will reduce the optical depth of butane clouds by a factor of 100 because the particles will be fewer in number for a given condensed mass. C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Univ Colorado, Cooperat Inst Res Environm Sci, Boulder, CO 80309 USA. Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA. Univ Colorado, Lab Astrophys & Space Phys, Boulder, CO 80309 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Tolbert, MA (reprint author), Univ Colorado, Dept Chem & Biochem, Campus Box 215, Boulder, CO 80309 USA. EM tolbert@colorado.edu NR 42 TC 7 Z9 7 U1 0 U2 8 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 FEB 24 PY 2005 VL 109 IS 7 BP 1382 EP 1390 DI 10.1021/jp045596h PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 898XC UT WOS:000227108500017 PM 16833455 ER PT J AU Zahnle, K AF Zahnle, K TI Planetary science - Being there SO NATURE LA English DT Editorial Material ID SOLAR-WIND; ORIGIN; ATMOSPHERE C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Zahnle, K (reprint author), NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA. EM kevin.j.zahnle@nasa.gov NR 13 TC 2 Z9 2 U1 1 U2 8 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD FEB 24 PY 2005 VL 433 IS 7028 BP 814 EP 815 DI 10.1038/433814b PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 899VT UT WOS:000227174600027 PM 15729325 ER PT J AU Rowlands, DD Luthcke, SB Klosko, SM Lemoine, FGR Chinn, DS McCarthy, JJ Cox, CM Anderson, OB AF Rowlands, DD Luthcke, SB Klosko, SM Lemoine, FGR Chinn, DS McCarthy, JJ Cox, CM Anderson, OB TI Resolving mass flux at high spatial and temporal resolution using GRACE intersatellite measurements SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GRAVITY; MISSION; FIELD AB [1] The GRACE mission is designed to monitor mass flux on the Earth's surface at one month and high spatial resolution through the estimation of monthly gravity fields. Although this approach has been largely successful, information at submonthly time scales can be lost or even aliased through the estimation of static monthly parameters. Through an analysis of the GRACE data residuals, we show that the fundamental temporal and spatial resolution of the GRACE data is 10 days and 400 km. We present an approach similar in concept to altimetric methods that recovers submonthly mass flux at a high spatial resolution. Using 4degrees x 4degrees blocks at 10-day intervals, we estimate the mass of surplus or deficit water over a 52degrees x 60degrees grid centered on the Amazon basin for July 2003. We demonstrate that the recovered signals are coherent and correlate well with the expected hydrological signal. C1 NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Greenbelt, MD 20771 USA. SGT Inc, Greenbelt, MD 20770 USA. Raytheon ITSS, Upper Marlboro, MD 20774 USA. Kort & Matrikelstyrelsen, DK-2400 Copenhagen, Denmark. RP Rowlands, DD (reprint author), NASA, Goddard Space Flight Ctr, Space Geodesy Branch, Code 926, Greenbelt, MD 20771 USA. EM david.d.rowlands@nasa.gov; frank.g.lemoine@nasa.gov RI Rowlands, David/D-2751-2012; Luthcke, Scott/D-6283-2012; Lemoine, Frank/D-1215-2013; Andersen, Ole /H-7481-2016 OI Andersen, Ole /0000-0002-6685-3415 NR 11 TC 108 Z9 113 U1 1 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 23 PY 2005 VL 32 IS 4 AR L04310 DI 10.1029/2004GL021908 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 904VC UT WOS:000227525200005 ER PT J AU Evans, JP Oglesby, RJ Lapenta, WM AF Evans, JP Oglesby, RJ Lapenta, WM TI Time series analysis of regional climate model performance SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID RIVER-BASIN EXPERIMENT; SURFACE PARAMETRIZATION SCHEMES; DELTA-EDDINGTON APPROXIMATION; LAND-SURFACE; BOUNDARY-LAYER; SOIL-MOISTURE; PRAIRIE GRASSLAND; TEMPORAL ANALYSIS; BIOSPHERE MODEL; FORECAST MODEL AB [1] Four regional climate models (RegCM2, MM5/BATS, MM5/SHEELS, and MM5/OSU) were intercompared on a fairly small domain covering a relatively homogenous area in Kansas, United States, including the First International Satellite Land Surface Climatology Project (SLSCP) Field Experiment (FIFE) site. The models were integrated for a 2-year period covering 1987 and 1988. The model results are evaluated against data collected during this time period at the Konza Prairie Long-Term Ecological Research (LTER) site as well as over the summer observation periods of FIFE. The models all captured the proper qualitative behavior of the interannual variability, though the magnitudes varied considerably between models. They also found it particularly difficult to reproduce observed changes in the variance of surface variables. No model performed consistently better, with each model displaying particular strengths and weaknesses of its own. RegCM2 could be improved by including an ice phase in the cloud microphysics parameterization. MM5/BATS and MM5/SHEELS need revision of the formulation of stability dependence of the surface drag coefficients, including the coupling to the wind field, as well as using a total soil depth more representative of the area. MM5/OSU simulates too much resistance to evapotranspiration and fails to close the energy budget. All of the models overestimate runoff and evapotranspiration during winter, creating a dry anomaly which persists throughout the following summer. Development and verification of parameterizations involved in coupling the land surface and atmospheric components of these models together is at least as important as the development and verification of each component individually. C1 Yale Univ, Dept Geol & Geophys, New Haven, CT 06511 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Yale Univ, Dept Geol & Geophys, New Haven, CT 06511 USA. EM jason.evans@yale.edu RI Evans, Jason/F-3716-2011 OI Evans, Jason/0000-0003-1776-3429 NR 61 TC 14 Z9 14 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X EI 2169-8996 J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 23 PY 2005 VL 110 IS D4 AR D04104 DI 10.1029/2004JD005046 PG 23 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 904VJ UT WOS:000227525900002 ER PT J AU Kaufman, YJ Koren, I Remer, LA Tanre, D Ginoux, P Fan, S AF Kaufman, YJ Koren, I Remer, LA Tanre, D Ginoux, P Fan, S TI Dust transport and deposition observed from the Terra-Moderate Resolution Imaging Spectroradiometer ( MODIS) spacecraft over the Atlantic ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AEROSOL-SIZE DISTRIBUTION; SUN PHOTOMETER MEASUREMENTS; EQUATORIAL NORTH-ATLANTIC; SAHARAN DUST; MINERAL DUST; OPTICAL-THICKNESS; SOIL DUST; TROPOSPHERIC AEROSOLS; ATMOSPHERIC TRANSPORT; SPECTRAL RADIANCES AB [1] Meteorological observations, in situ data, and satellite images of dust episodes were used already in the 1970s to estimate that 100 Tg of dust are transported from Africa over the Atlantic Ocean every year between June and August and are deposited in the Atlantic Ocean and the Americas. Desert dust is a main source of nutrients to oceanic biota and the Amazon forest, but it deteriorates air quality, as shown for Florida. Dust affects the Earth radiation budget, thus participating in climate change and feedback mechanisms. There is an urgent need for new tools for quantitative evaluation of the dust distribution, transport, and deposition. The Terra spacecraft, launched at the dawn of the last millennium, provides the first systematic well-calibrated multispectral measurements from the Moderate Resolution Imaging Spectroradiometer ( MODIS) instrument for daily global analysis of aerosol. MODIS data are used here to distinguish dust from smoke and maritime aerosols and to evaluate the African dust column concentration, transport, and deposition. We found that 240 +/- 80 Tg of dust are transported annually from Africa to the Atlantic Ocean, 140 +/- 40 Tg are deposited in the Atlantic Ocean, 50 Tg fertilize the Amazon Basin ( four times as previous estimates, thus explaining a paradox regarding the source of nutrition to the Amazon forest), 50 Tg reach the Caribbean, and 20 Tg return to Africa and Europe. The results are compared favorably with dust transport models for maximum particle diameter between 6 and 12 mm. This study is a first example of quantitative use of MODIS aerosol for a geophysical research. C1 Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. CNR, Greenbelt, MD 20771 USA. Univ Sci & Tech Lille Flandres Artois, Opt Atmospher Lab, F-59655 Villeneuve Dascq, France. RP Kaufman, YJ (reprint author), Princeton Univ, NOAA, Geophys Fluid Dynam Lab, Forrestal Campus,Route 1,POB 308, Princeton, NJ 08542 USA. EM kaufman@climate.gsfc.nasa.gov RI Ginoux, Paul/C-2326-2008; Koren, Ilan/K-1417-2012 OI Ginoux, Paul/0000-0003-3642-2988; Koren, Ilan/0000-0001-6759-6265 NR 66 TC 136 Z9 136 U1 1 U2 24 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 FEB 23 PY 2005 VL 110 IS D10 AR D10S12 DI 10.1029/2003JD004436 PG 16 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 904VQ UT WOS:000227526600001 ER PT J AU Vant-Hull, B Li, ZQ Taubman, BF Levy, R Marufu, L Chang, FL Doddridge, BG Dickerson, RR AF Vant-Hull, B Li, ZQ Taubman, BF Levy, R Marufu, L Chang, FL Doddridge, BG Dickerson, RR TI Smoke over haze: Comparative analysis of satellite, surface radiometer, and airborne in situ measurements of aerosol optical properties and radiative forcing over the eastern United States SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID BIOMASS-BURNING AEROSOL; MID-ATLANTIC COAST; SINGLE SCATTERING ALBEDO; BLACK CARBON; WAVELENGTH DEPENDENCE; SIZE DISTRIBUTION; LIGHT-ABSORPTION; BRAZIL; PARTICLES; CLIMATE AB [1] In July 2002 Canadian forest fires produced a major smoke episode that blanketed the east coast of the United States. Properties of the smoke aerosol were measured in situ from aircraft, complementing operational Aerosol Robotic Network (AERONET), and Moderate Resolution Imaging Spectroradiometer ( MODIS) remotely sensed aerosol retrievals. This study compares single scattering albedo and phase function derived from the in situ measurements and AERONET retrievals in order to evaluate their consistency for application to satellite retrievals of optical depth and radiative forcing. These optical properties were combined with MODIS reflectance observations to calculate optical depth. The use of AERONET optical properties yielded optical depths 2 - 16% lower than those directly measured by AERONET. The use of in situ - derived optical properties resulted in optical depths 22 - 43% higher than AERONET measurements. These higher optical depths are attributed primarily to the higher absorption measured in situ, which is roughly twice that retrieved by AERONET. The resulting satellite retrieved optical depths were in turn used to calculate integrated radiative forcing at both the surface and top of atmosphere. Comparisons to surface ( Surface Radiation Budget Network (SURFRAD) and ISIS) and to satellite ( Clouds and Earth Radiant Energy System CERES) broadband radiometer measurements demonstrate that the use of optical properties derived from the aircraft measurements provided a better broadband forcing estimate (21% error) than those derived from AERONET (33% error). Thus AERONET-derived optical properties produced better fits to optical depth measurements, while in situ properties resulted in better fits to forcing measurements. These apparent inconsistencies underline the significant challenges facing the aerosol community in achieving column closure between narrow and broadband measurements and calculations. C1 Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Univ Maryland, Dept Meteorol, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Vant-Hull, B (reprint author), Earth Syst Sci Interdisciplinary Ctr, College Pk, MD 20742 USA. EM brianvh@atmos.umd.edu RI Levy, Robert/M-7764-2013; Li, Zhanqing/F-4424-2010; Dickerson, Russell/F-2857-2010 OI Levy, Robert/0000-0002-8933-5303; Li, Zhanqing/0000-0001-6737-382X; Dickerson, Russell/0000-0003-0206-3083 NR 56 TC 2 Z9 2 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 FEB 23 PY 2005 VL 110 IS D10 AR D10S21 DI 10.1029/2004JD004518 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 904VQ UT WOS:000227526600002 ER PT J AU Tan, XF Salama, F AF Tan, XF Salama, F TI Cavity ring-down spectroscopy and theoretical calculations of the S-1(B-1(3u))<- S-0((1)A(g)) transition of jet-cooled perylene SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; DIFFUSE INTERSTELLAR BANDS; ELECTRONIC ABSORPTION-SPECTROSCOPY; MOLECULAR-ORBITAL THEORY; VIBRATIONAL REDISTRIBUTION; FLUORESCENCE-SPECTRA; INFRARED-SPECTRA; SUPERSONIC JET; CATIONS; DENSITY AB As part of our long-term program to test the diffuse interstellar band-polycyclic aromatic hydrocarbon hypothesis, we have investigated the S-1<--S-0 electronic transition of neutral perylene (C20H12) in a combined experimental and theoretical study. Jet-cooled perylene was prepared with a pulsed discharge slit nozzle and detected by cavity ring-down spectroscopy. A number of vibronic features were observed in the 24 000-24 900 cm(-1) spectral range. Density functional and ab initio calculations were performed to determine the geometries, harmonic vibrational frequencies, and normal coordinates of both the S-0 and S-1 electronic states. A rotational temperature of 52+/-5 K was derived from a rotational contour analysis of the vibronic band associated with the 0-0 transition. A Franck-Condon treatment was carried out to calculate the vibronic spectrum of the S-1<--S-0 transition. A good agreement was found between the calculated and the experimental spectra. A vibrational assignment is proposed and six normal modes are identified. The contribution of neutral compact polycyclic aromatic hydrocarbons to the diffuse interstellar bands is briefly discussed. (C) 2005 American Institute of Physics. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP NASA, Ames Res Ctr, Div Space Sci, Mail Stop 245-6, Moffett Field, CA 94035 USA. EM x.tan@jhu.edu; Farid.Salama@nasa.gov RI Salama, Farid/A-8787-2009 OI Salama, Farid/0000-0002-6064-4401 NR 54 TC 42 Z9 42 U1 3 U2 18 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 22 PY 2005 VL 122 IS 8 AR 084318 DI 10.1063/1.1851502 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 902QS UT WOS:000227372200040 PM 15836050 ER PT J AU Liu, JP Curry, JA Rossow, WB Key, JR Wang, XJ AF Liu, JP Curry, JA Rossow, WB Key, JR Wang, XJ TI Comparison of surface radiative flux data sets over the Arctic Ocean SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SEA-ICE; MODEL; SENSITIVITY; REANALYSIS; BUDGET AB Recent satellite data analysis and reanalysis projects have provided an unprecedented wealth of data sets relevant to surface energy budget in the Arctic Ocean. To assess how well we can reconstruct the variations of surface radiative fluxes used as boundary conditions to force sea ice models, the surface temperature, surface downwelling shortwave and longwave radiative fluxes of the (1) Cloud and Surface Parameter Retrieval (CASPR), (2) International Satellite Cloud Climatology Project (ISCCP-FD), (3) National Centers for Environmental Prediction Reanalysis II (NCEP- R2), and (4) European Centre for Medium-Range Weather Forecast 40-Year Reanalysis (ERA- 40) were evaluated over the period November 1997 to September 1998. At the local scale the accuracy of these surface parameters was compared to the high-quality in situ measurements from the Surface Heat Budget of the Arctic Ocean (SHEBA) over the seasonal cycle and during particular storm events. The CASPR and NCEP- R2 are closer to the SHEBA for the surface temperature. The CASPR and ISCCP-FD are more accurate for the surface downward shortwave radiative fluxes. The ERA- 40 agrees well with the SHEBA for the surface downward longwave radiative fluxes. At the basin scale the consistency of dominant spatial/temporal variability of these surface parameters across different data sets was examined. All data sets reproduce the patterns associated with the seasonal cycle, but they vary in their ability to capture patterns linked to synoptic variability. C1 Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. Polar Res Inst China, Key Lab Polar Sci, Shanghai, Peoples R China. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. NOAA, Natl Environm Satellite Data & Informat Serv, Off Res & Applicat, Madison, WI USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI USA. RP Georgia Inst Technol, Sch Earth & Atmospher Sci, Atlanta, GA 30332 USA. EM jliu@eas.gatech.edu; curryja@eas.gatech.edu; wrossow@giss.nasa.gov; jkey@ssec.wisc.edu; xuanjiw@ssec.wisc.edu RI Key, Jeffrey/F-5597-2010; Rossow, William/F-3138-2015; LIU, JIPING/N-6696-2016 OI Key, Jeffrey/0000-0001-6109-3050; NR 21 TC 30 Z9 32 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 22 PY 2005 VL 110 IS C2 AR C02015 DI 10.1029/2004JC002381 PG 13 WC Oceanography SC Oceanography GA 904VU UT WOS:000227527000004 ER PT J AU Frimer, AA Gilinsky-Sharon, P Gottlieb, HE Meador, MAB Johnston, JC AF Frimer, AA Gilinsky-Sharon, P Gottlieb, HE Meador, MAB Johnston, JC TI Tetrahydrophthalic anhydrides as addition curing polyimide end caps: Thermal isomerization of methylendianiline 3,6-diphenyltetrahydrophthalic bisimides SO MACROMOLECULES LA English DT Article ID IMPROVED OXIDATION RESISTANCE; CAPPED POLYIMIDES; DEGRADATION; CYCLOHEXENE C1 Bar Ilan Univ, Dept Chem, IL-52900 Ramat Gan, Israel. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Frimer, AA (reprint author), Bar Ilan Univ, Dept Chem, IL-52900 Ramat Gan, Israel. OI Meador, Mary Ann/0000-0003-2513-7372 NR 12 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD FEB 22 PY 2005 VL 38 IS 4 BP 1504 EP 1507 DI 10.1021/ma048697m PG 4 WC Polymer Science SC Polymer Science GA 898OF UT WOS:000227085400064 ER PT J AU Pirjola, R Kauristie, K Lappalainen, H Viljanen, A Pulkkinen, A AF Pirjola, R Kauristie, K Lappalainen, H Viljanen, A Pulkkinen, A TI Space weather risk SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS LA English DT Article ID GEOMAGNETICALLY INDUCED CURRENTS; NATURAL-GAS PIPELINE; VOLTAGE POWER-SYSTEM; COMPLEX-IMAGE METHOD; AURORAL ELECTROJET; MAGNETIC-FIELDS; SURFACE; NETWORKS; EARTH AB [1] The importance of space weather to society is in a continuous increase since we are more and more dependent on reliable spaceborne and ground-based technological systems. Physical processes involved in space weather constitute a complicated chain from the Sun to the Earth's surface, so the management of space weather risks requires expertise in many disciplines of science and technology. In this paper, geomagnetically induced currents in electric power networks are considered in detail, referring particularly to research carried out in Finland. Today's monitoring systems of natural risks, such as floods and forest fires, are based on satellite observations. Spacecraft and communication between satellites and the ground are vulnerable to space weather. Thus, besides being a direct risk to technology, space weather may also indirectly have adverse effects on risk management. European efforts, which take into account both aspects, are also discussed in this paper. C1 Finnish Meteorol Inst, Space Res Inst, FIN-00101 Helsinki, Finland. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Pirjola, R (reprint author), Finnish Meteorol Inst, Space Res Inst, POB 503, FIN-00101 Helsinki, Finland. EM risto.pirjola@fmi.fi NR 50 TC 23 Z9 23 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1542-7390 J9 SPACE WEATHER JI Space Weather PD FEB 22 PY 2005 VL 3 IS 2 AR S02A02 DI 10.1029/2004SW000112 PG 11 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 909UD UT WOS:000227885300001 ER PT J AU Aslam, S Vest, RE Franz, D Yan, F Zhao, YG Mott, B AF Aslam, S Vest, RE Franz, D Yan, F Zhao, YG Mott, B TI External quantum efficiency of Pt/n-GaN Schottky diodes in the spectral range 5-500nm SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE Schottky photodiode; GaN; leakage current; quantum efficiency; spatial uniformity; radiation hardness ID FAR-ULTRAVIOLET; UV DETECTORS; PHOTODIODES; PHOTODETECTORS; REGION AB The external quantum efficiency in the spectral wavelength range 5-500 nm of a large active area Pt/n-type GaN Schottky photodiode that exhibits low reverse bias leakage current, is reported. The Schottky photodiodes were fabricated from n(-)/n(+) epitaxial layers grown by low pressure metalorganic vapour phase epitaxy on single crystal c-plane sapphire. The current voltage (I- V) characteristics of several 0.25 cm 2 devices are presented together with the capacitance-voltage (C- V) characteristics of one of these devices. A leakage current as low as 14 pA at 0. 5 V reverse bias is reported, for a 0.25 cm 2 diode. The ultraviolet quantum efficiency measurements show that the diodes can be used as radiation hard detectors for the 5-365 tun spectral range without the use of visible blocking filters. A peak responsivity of 77.5 mA/W at 320 nm is reported for one of the fabricated devices, corresponding to a spectral detectivity, D* = 1.5 x 10(14) cm Hz(1/2) W-1. The average detectivity between 250 and 350 run, for the same device, is reported to be D* = 1.3 x 10(14) cm, Hz(1/2) W-1. The spatial responsivity uniformity variation was established, using H-2 Lyman-alpha radiation, to be +/-3% across the surface of a typical 0.25cm(2) diode. (C) 2004 Elsevier B.V. All rights reserved. C1 Raytheon ITSS, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NIST, Gaithersburg, MD 20899 USA. Keithley Instruments Inc, Cleveland, OH 44139 USA. RP Aslam, S (reprint author), Raytheon ITSS, 4400 Forbes Blvd, Lanham, MD 20706 USA. EM saslam@pop200.gsfc.nasa.gov RI Aslam, Shahid/D-1099-2012 NR 25 TC 11 Z9 12 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 21 PY 2005 VL 539 IS 1-2 BP 84 EP 92 DI 10.1016/j.nima.2004.09.042 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 904DG UT WOS:000227475700009 ER PT J AU Misaki, K Hidaka, Y Ishida, M Shibata, R Furuzawa, A Haba, Y Itoh, K Mori, H Kunieda, H AF Misaki, K Hidaka, Y Ishida, M Shibata, R Furuzawa, A Haba, Y Itoh, K Mori, H Kunieda, H TI X-ray telescope onboard Astro-E. III. Guidelines to performance improvements and optimization of the ray-tracing simulator SO APPLIED OPTICS LA English DT Article ID CALIBRATION; MIRRORS; SATELLITE; IMAGE AB We present a detailed study of the performance of the Astro-E x-ray telescope (XRT) onboard the Astro-E satellite. As described in preceding papers the ground-based calibrations of the Astro-E XRT revealed that its image quality and effective area are somewhat worse than that expected from the original design. Conceivable causes for such performance degradation are examined by x-ray and optical microscopic measurements at various levels, such as individual reflectors, sectors, and quadrants of the XRT and their alignments. We can attribute, based on detailed measurements, the degradation of the image quality to a slope error in the individual reflectors and the positioning error of reflectors. As for the deficit of the effective area, the shadowing of x rays within the XRT body is the dominant factor. Error budgets for the performance degradation of the Astro-E XRT are summarized. The ray-tracing simulator, which is needed to construct the response function for arbitrary off-axis angles and spatial distributions of any celestial x-ray sources, has been developed and tuned based on the results of detailed measurements. The ray-tracing simulation provides results that are consistent within 3% with the real measurement except for large off-axis angles and higher energies. We propose, based on knowledge obtained from all the measurements and simulations, several plans for future developments to improve the performance of the nested thin-foil mirrors. (C) 2005 Optical Society of America. C1 Inst Space & Astronom Sci, Kanagawa 2298510, Japan. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Nagoya Univ, Dept Phys, Chikusa Ku, Nagoya, Aichi 4648602, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo 1290397, Japan. Nikon Inc, Chiyoda Ku, Tokyo 1008331, Japan. RP Misaki, K (reprint author), Inst Space & Astronom Sci, 3-1-1 Yoshinodai, Kanagawa 2298510, Japan. EM misaki@milkyway.gsfc.nasa.gov NR 14 TC 10 Z9 10 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 FEB 20 PY 2005 VL 44 IS 6 BP 916 EP 940 DI 10.1364/AO.44.000916 PG 25 WC Optics SC Optics GA 900GN UT WOS:000227203500012 PM 15751683 ER PT J AU Weiner, BJ Phillips, AC Faber, SM Willmer, CNA Vogt, NP Simard, L Gebhardt, K Im, MS Koo, DC Sarajedini, VL Wu, KL Forbes, DA Gronwall, C Groth, EJ Illingworth, GD Kron, RG Rhodes, J Szalay, AS Takamiya, M AF Weiner, BJ Phillips, AC Faber, SM Willmer, CNA Vogt, NP Simard, L Gebhardt, K Im, MS Koo, DC Sarajedini, VL Wu, KL Forbes, DA Gronwall, C Groth, EJ Illingworth, GD Kron, RG Rhodes, J Szalay, AS Takamiya, M TI The DEEP Groth Strip Galaxy Redshift Survey. III. Redshift catalog and properties of galaxies SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : distances and redshifts; galaxies : evolution; galaxies : fundamental parameters; galaxies : high-redshift; galaxies : structure; surveys ID HUBBLE-SPACE-TELESCOPE; DIGITAL SKY SURVEY; SPECTRAL ENERGY-DISTRIBUTIONS; COLOR-MAGNITUDE RELATION; STAR-FORMATION HISTORY; EXTREMELY RED GALAXIES; LUMINOSITY FUNCTION; FIELD NORTH; LARGE-SCALE; GLOBAL PROPERTIES AB The Deep Extragalactic Evolutionary Probe ( DEEP) is a series of spectroscopic surveys of faint galaxies, targeted at understanding the properties and clustering of galaxies at redshifts z similar to 1. We present the redshift catalog of the DEEP1 Groth Strip pilot phase of this project, a Keck LRIS survey of faint galaxies in the Groth Survey Strip imaged with HST WFPC2. The redshift catalog and data, including reduced spectra, are made publicly available through a Web-accessible database. The catalog contains 658 secure galaxy redshifts with a median z = 0.65. The distribution of these galaxies shows large-scale structure walls to z similar to 1. We find a bimodal distribution in the galaxy color-magnitude diagram that persists to the same distance. A similar color division has been seen locally by the SDSS and to z similar to 1 by the COMBO-17 survey. The HST imaging allows us to measure structural properties of the galaxies, and we find that the color division corresponds generally to a structural division. Most red galaxies, similar to 75%, are centrally concentrated, with a red bulge or spheroidal stellar component, while blue galaxies usually have exponential profiles. However, there are two subclasses of red galaxies that are not bulge dominated: edge-on disks and a second category that we term diffuse red galaxies (DIFRGs). Comparison to a local sample drawn from the RC3 suggests that distant edge-on disks are similar in appearance and frequency to those at low redshift, but analogs of DIFRGs are rare among local red galaxies. DIFRGs have significant emission lines, indicating that they are reddenedmainly by dust rather than age. The DIFRGs in our sample are all at z > 0.64, suggesting that DIFRGs are more prevalent at high redshifts; they may be related to the dusty or irregular extremely red objects beyond z > 1: 2 that have been found in deep K-selected surveys. We measure the color evolution of both red and blue galaxies by comparing our U - B colors to those from the RC3. For red galaxies, we find a reddening of only 0.11 mag from z similar to 0.8 to now, about half the color evolution measured by COMBO-17. Larger, more carefully defined samples with better colors are needed to improve this measurement. Reconciling evolution in color, luminosity, mass, morphology, and star formation rates will be an active topic of future research. C1 Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA. Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7, Canada. Univ Texas, Dept Astron, Austin, TX 78723 USA. Seoul Natl Univ, SEES, Astron Program, Seoul 151742, South Korea. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. Swinburne Univ Technol, Ctr Astrophys & Supercomp, Hawthorn, Vic 3122, Australia. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Univ Chicago, Yerkes Observ, Williams Bay, WI 53191 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Hawaii, Inst Astron, Hilo, HI 96720 USA. RP Weiner, BJ (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. EM bjw@ucolick.org RI Im, Myungshin/B-3436-2013; OI Im, Myungshin/0000-0002-8537-6714; Weiner, Benjamin/0000-0001-6065-7483 NR 78 TC 139 Z9 139 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 FEB 20 PY 2005 VL 620 IS 2 BP 595 EP 617 DI 10.1086/427256 PN 1 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DN UT WOS:000227405800005 ER PT J AU Baumgartner, WH Loewenstein, M Horner, DJ Mushotzky, RF AF Baumgartner, WH Loewenstein, M Horner, DJ Mushotzky, RF TI Intermediate-element abundances in galaxy clusters SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : abundances; intergalactic medium; supernovae : general; X-rays : galaxies : clusters ID XMM-NEWTON OBSERVATIONS; INITIAL MASS FUNCTION; 4 RICH CLUSTERS; X-RAY-SPECTRA; INTRACLUSTER MEDIUM; INTERGALACTIC MEDIUM; INTERSTELLAR-MEDIUM; ELLIPTIC GALAXIES; PERSEUS CLUSTER; POPULATION-III AB We present the average abundances of the intermediate elements obtained by performing a stacked analysis of all the galaxy clusters in the archive of the X-ray telescope ASCA. We determine the abundances of Fe, Si, S, and Ni as a function of cluster temperature ( mass) from 1 - 10 keV and place strong upper limits on the abundances of Ca and Ar. In general, Si and Ni are overabundant with respect to Fe, while Ar and Ca are very underabundant. The discrepancy between the abundances of Si, S, Ar, and Ca indicate that the alpha-elements do not behave homogeneously as a single group. We show that the abundances of the most well-determined elements Fe, Si, and S in conjunction with recent theoretical supernova yields do not give a consistent solution for the fraction of material produced by Type Ia and Type II supernovae at any temperature or mass. The general trend is for higher temperature clusters to have more of their metals produced in Type II supernovae than in Type Ia supernovae. The inconsistency of our results with abundances in the Milky Way indicate that spiral galaxies are not the dominant metal contributors to the intracluster medium (ICM). The pattern of elemental abundances requires an additional source of metals beyond standard Type Ia and Type II supernova enrichment. The properties of this new source are well matched to those of Type II supernovae with very massive, metal-poor progenitor stars. These results are consistent with a significant fraction of the ICM metals produced by an early generation of Population III stars. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. RP Univ Maryland, Dept Astron, College Pk, MD 20742 USA. EM wayne@srl.caltech.edu NR 70 TC 73 Z9 73 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 FEB 20 PY 2005 VL 620 IS 2 BP 680 EP 696 DI 10.1086/427158 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DN UT WOS:000227405800011 ER PT J AU Menanteau, F Martel, AR Tozzi, P Frye, B Ford, HC Infante, L Benitez, N Galaz, G Coe, D Illingworth, GD Hartig, GF Clampin, M AF Menanteau, F Martel, AR Tozzi, P Frye, B Ford, HC Infante, L Benitez, N Galaz, G Coe, D Illingworth, GD Hartig, GF Clampin, M TI The nature of blue cores in spheroids: A possible connection with active galactic nuclei and star formation SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : elliptical and lenticular, cD; X-rays : galaxies ID HUBBLE-DEEP-FIELD; FORMATION RATE INDICATOR; 2-10 KEV LUMINOSITY; EARLY-TYPE GALAXIES; SIMILAR-TO 0.7; FORMING GALAXIES; SEQUENCE; SOUTH; EVOLUTION; EMISSION AB We investigate the physical nature of blue cores in early-type galaxies through the first multiwavelength analysis of a serendipitously discovered field blue-nucleated spheroid in the background of the deep Hubble Space Telescope ACS/WFC griz multicolor observations of the cluster A1689. The resolved g - r, r - i, and i - z color maps reveal a prominent blue core identifying this galaxy as a "typical'' case study, exhibiting variations of 0.5 - 1.0 mag in color between the center and the outer regions, opposite to the expectations of reddened metallicity- induced gradients in passively evolved elliptical galaxies. From a Magellan-Clay telescope spectrum we secure the galaxy redshift at z = 0.624. We find a strong X-ray source coincident with the spheroid galaxy. Spectral features and a high X-ray luminosity indicate the presence of an active galactic nucleus (AGN) in the galaxy. However, a comparison of the X-ray luminosity to a sample derived from the Chandra Deep Field - South displays L-X to be comparable to type 1/QSO galaxies while the optical flux is consistent with a normal star-forming galaxy. We conclude that the galaxy's nonthermal component dominates at high-energy wavelengths, while we associate the spheroid blue light with the stellar spectrum of normal star-forming galaxies. We argue for a probable association between the presence of blue cores in spheroids and AGN activity. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Osserv Astron Trieste, INAF, I-34131 Trieste, Italy. Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile. CSIC, Inst Astrofis Andalucia, E-18008 Granada, Spain. Univ Calif Santa Cruz, Univ Calif Observ, Lick Observ, Santa Cruz, CA 95064 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Menanteau, F (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. RI Clampin, mark/D-2738-2012; OI Benitez, Narciso/0000-0002-0403-7455 NR 27 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 FEB 20 PY 2005 VL 620 IS 2 BP 697 EP 702 DI 10.1086/427232 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DN UT WOS:000227405800012 ER PT J AU Snell, RL Hollenbach, D Howe, JE Neufeld, DA Kaufman, MJ Melnick, GJ Bergin, EA Wang, Z AF Snell, RL Hollenbach, D Howe, JE Neufeld, DA Kaufman, MJ Melnick, GJ Bergin, EA Wang, Z TI Detection of water in the shocked gas associated with IC 443: Constraints on shock models SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : clouds; ISM : molecules; radio lines : ISM; shock waves; supernova remnants ID SUPERNOVA REMNANT IC-443; WAVE-ASTRONOMY-SATELLITE; INTER-STELLAR SHOCKS; MOLECULE FORMATION; INFRARED-EMISSION; NOVA REMNANT; PHYSICAL PROCESSES; H-2 EMISSION; CO EMISSION; CHEMISTRY AB We have used the Submillimeter Wave Astronomy Satellite (SWAS) to observe the ground-state 1(10) --> 1(01) transition of ortho-H2O at 557 GHz in three of the shocked molecular clumps associated with the supernova remnant IC 443. We also observed simultaneously the 487 GHz line (3, 1 --> 3; 2) of O-2, the 492 GHz line (P-3(1) --> P-3(0)) of C I, and the 550 GHz line ( J = 5 --> 4) of (CO)-C-13. We detected the H2O, C I, and (CO)-C-13 lines toward the shocked clumps B, C, and G. In addition, ground-based observations of the J = 1 --> 0 transitions of CO and HCO+ were obtained. Assuming that the shocked gas has a temperature of 100 K and a density of 5 x 10(5) cm(-3), we derive SWAS beam-averaged ortho- H2O column densities of 3.2 x 10(13), 1,8 x 10(13), and 3.9 x 10(13) cm(-2) in clumps B, C, and G, respectively. Combining the SWAS results with our ground-based observations, we derive a relative abundance of ortho- H2O to CO in the postshock gas of between 2 x 10(-4) and 3 x 10(-3). On the basis of our results for H2O, published results of numerous atomic and molecular shock tracers, and archival Infrared Space Observatory (ISO) observations, we conclude that no single shock type can explain these observations. However, a combination of fast J-type shocks (similar to 100 km s(-1)) and slow C-type shocks (similar to 12 km s(-1)) or, more likely, slow J-type shocks (similar to 12 - 25 km s(-1)) can most naturally explain the postshock velocities and the emission seen in various atomic and molecular tracers. Such a superposition of shocks might be expected as the supernova remnant overtakes a clumpy interstellar medium. The fast J-type shocks provide a strong source of ultraviolet radiation, which photodissociates the H2O in the cooling ( T less than or equal to 300 K) gas behind the slow shocks and strongly affects the slow C-type shock structure by enhancing the fractional ionization. At these high ionization fractions, C-type shocks break down at speeds similar to 10 - 12 km s(-1), while faster flows will produce J-type shocks. Our model favors a preshock gas-phase abundance of oxygen not in CO that is depleted by a least a factor of 2, presumably as water ice on grain surfaces. Both freezeout of H2O and photodissociation of H2O in the postshock gas must be significant to explain the weak H2O emission seen by SWAS and ISO from the shocked and postshock gas. C1 Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. San Jose State Univ, Dept Phys, San Jose, CA 95192 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Snell, RL (reprint author), Univ Massachusetts, Dept Astron, LGRT 619,710 N Pleasant St, Amherst, MA 01003 USA. NR 58 TC 48 Z9 49 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 FEB 20 PY 2005 VL 620 IS 2 BP 758 EP 773 DI 10.1086/427231 PN 1 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DN UT WOS:000227405800017 ER PT J AU Peeters, E Tielens, AGGM Boogert, ACA Hayward, TL Allamandola, LJ AF Peeters, E Tielens, AGGM Boogert, ACA Hayward, TL Allamandola, LJ TI The prominent dust emission feature near 8.9 mu m in four HII regions SO ASTROPHYSICAL JOURNAL LA English DT Review DE HII regions; infrared : ISM; ISM : lines and bands; ISM : molecules ID H-II REGIONS; POLYCYCLIC AROMATIC-HYDROCARBONS; FAR-INFRARED OBSERVATIONS; RADIO RECOMBINATION LINE; HIGH-ANGULAR RESOLUTION; METHANOL MASER SURVEY; STAR-FORMING REGIONS; MOLECULAR CLOUD; INTERSTELLAR DUST; MASSIVE STARS AB We present a mid-infrared study of four H II regions based on the combination of Infrared Space Observatory (ISO) SWS observations with spatial information from SpectroCam-10 images and long-slit spectra. We report a prominent broad emission feature near 8.9 mum. The peak position and width of this feature do not resemble known polycyclic aromatic hydrocarbon ( PAH) or dust emission features. Its spatial distribution is analyzed for two H II regions and is clearly distinct from that of the PAH emission features, being more similar to that of the ionized gas and especially to the spatial distribution of the dust continuum at 15 mum. Thus, the carrier of this band likely resides within the H II region. Possible carriers of this feature are highlighted. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. SRON Netherlands Inst Space Res, NL-9700 AV Groningen, Netherlands. Kapteyn Inst, NL-9700 AV Groningen, Netherlands. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. Gemini Observ, So Operat Ctr, La Serena, Chile. RP NASA, Ames Res Ctr, MS 245-6, Moffett Field, CA 94035 USA. EM epeeters@mail.arc.nasa.gov NR 109 TC 11 Z9 11 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 FEB 20 PY 2005 VL 620 IS 2 BP 774 EP 785 DI 10.1086/427143 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DN UT WOS:000227405800018 ER PT J AU Sahai, R Contreras, CS Morris, M AF Sahai, R Contreras, CS Morris, M TI A starfish preplanetary nebula: IRAS 19024+0044 SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; ISM : refection nebulae; planetary nebulae : general; stars : AGB and post-AGB; stars : individual (IRAS 19024+0044); stars : mass loss ID BIPOLAR PROTOPLANETARY NEBULA; MULTIPLE COLLIMATED OUTFLOWS; YOUNG PLANETARY-NEBULAE; POST-AGB STARS; MASS-LOSS; GIANT BRANCH; CIRCUMSTELLAR ENVELOPES; ACCRETION DISKS; CARBON STARS; EGG NEBULA AB Using the Hubble Space Telescope, we have imaged the OH/IR star IRAS 19024+0044 (I19024) at 0.6, 0.8, 1.1, and 1.6 mum, as part of our surveys of candidate preplanetary nebulae. The images show a multipolar nebula of size similar to3."7 x 2."3, with at least six elongated lobes emanating from the center of the nebula. Two of the lobes show limb-brightened tips having point-symmetric structure with respect to the expected location of the central star. The central region shows two dark bands southwest and northeast of a central shallow maximum that may be either two inclined dusty toroidal structures or the dense parts of a single wide, inhomogeneous, toroid. A very faint, surface brightness - limited, diffuse halo surrounds the lobes. Long-slit /echelle optical spectroscopy obtained at the Mount Palomar and Keck observatories shows a spatially compact source of Halpha emission; the Halpha line shows a strong, narrow, central core with very broad (+/- 1000 km s(-1)), weak wings, and a narrower blueshifted absorption feature signifying the presence of a similar to 100 km s(-1) outflow. The spectrum is characterized by a strong, relatively featureless, continuum and lacks the strong forbidden emission lines characteristic of planetary nebulae, confirming that IRAS 19024 is a preplanetary nebula; the spectral type for the central star, although uncertain, is most likely early G. Interferometric observations of the CO J = 1-0 line emission with the Owens Valley Radio Interferometer show a marginally resolved molecular envelope ( size 5."5 x 4."4) with an expansion velocity of 13 km s(-1), resulting from the asymptotic giant granch (AGB) progenitor's dense, slow wind. We derive a kinematic distance of 3.5 kpc to I19024, based on its radial velocity. The bolometric flux is 7.3 x 10(-9) ergs s(-1) cm(-2), and the luminosity 2850 L-.. The relatively low luminosity of I19024, in comparison with stellar evolutionary models, indicates that the initial mass of its central star was similar to1 - 1.5 M-.. The lobes, which appear to be hollow structures with dense walls, have a total mass greater than or equal to about 0.02M(.). The dusty tori in the center have masses of a few times 10(-3) M-.. The faint halo has a power-law radial surface brightness profile with an exponent of about - 3 and most likely represents the remnant spherical circumstellar envelope formed as a result of constant mass loss during the AGB phase over the past several thousand years. From the CO data we infer a molecular mass greater than or similar to0.025 M-. and an expansion age less than or similar to2870 yr, giving a mass-loss rate greater than or similar to10(-5) M-. yr(-1). The far-infrared fluxes of I19024 indicate the presence of a large mass of cool dust in the nebula; from a simple model we infer the presence of "cool'' ( 109 K) and "warm'' ( 280 K) components of dust mass 5.7 x 10(-4) and 1.5 x 10(-7) M-.. We discuss our results for I19024 in the light of past and current ideas for the dramatic transformation of the morphology and kinematics of mass-ejecta as AGB stars evolve into planetary nebulae. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Div Astron & Astrophys, Los Angeles, CA 90095 USA. RP Sahai, R (reprint author), CALTECH, Jet Prop Lab, MS 183-900, Pasadena, CA 91109 USA. EM raghvendra.sahai@jpl.nasa.gov NR 53 TC 18 Z9 18 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 2005 VL 620 IS 2 BP 948 EP 960 DI 10.1086/426469 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DN UT WOS:000227405800035 ER PT J AU Davis, SS AF Davis, SS TI Condensation front migration in a protoplanetary nebula SO ASTROPHYSICAL JOURNAL LA English DT Article DE planetary systems : formation; solar system : formation ID PRIMORDIAL SOLAR NEBULA; ACCRETION DISKS; VERTICAL STRUCTURE; CHEMICAL-REACTIONS; T-TAURI; MODELS; DUST; EVOLUTION; REDISTRIBUTION; TEMPERATURE AB Condensation-front dynamics is investigated in the solar nebula. A quasi-steady model of the evolving nebula is combined with equilibrium vapor pressure curves to determine evolutionary sublimation fronts for water and ammonia. A simple one-dimensional model includes local viscous and luminescent heating, allowing analytical solutions. The study is extended to two-dimensional protoplanetary disks including grain heating in the disk photosphere and vertical radiative transfer. Both approaches show the fronts migrating inward from the far nebula to final positions in the inner nebula during a period of 10(7) yr. The center-plane sublimation fronts are shown to evolve in a similarmanner, but the two-dimensional model predicts a more complex two-branched structure. One branch forms an elongated gaseous region below the density scale height, and the second branch places a sublimation front in the low-density region near the disk photosphere. Along the center plane, the fronts initially propagate much faster than the nebular viscous accretion velocity, but eventually the accreting gas and dust overtake the slowing condensation front. C1 NASA, Space Sci & Astrobiol Div, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Davis, SS (reprint author), NASA, Space Sci & Astrobiol Div, Ames Res Ctr, MS 245-3, Moffett Field, CA 94035 USA. EM sdavis@mail.arc.nasa.gov NR 39 TC 29 Z9 29 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 FEB 20 PY 2005 VL 620 IS 2 BP 994 EP 1001 DI 10.1086/427073 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DN UT WOS:000227405800039 ER PT J AU Rieke, GH Su, KYL Stansberry, JA Trilling, D Bryden, G Muzerolle, J White, B Gorlova, N Young, ET Beichman, CA Stapelfeldt, KR Hines, DC AF Rieke, GH Su, KYL Stansberry, JA Trilling, D Bryden, G Muzerolle, J White, B Gorlova, N Young, ET Beichman, CA Stapelfeldt, KR Hines, DC TI Decay of planetary debris disks SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; infrared : stars; planetary systems : formation ID MAIN-SEQUENCE STARS; RHO-OPHIUCHI CLOUD; SYSTEM DUST BANDS; OPEN CLUSTERS; SOLAR-SYSTEM; EFFECTIVE TEMPERATURE; INFRARED PHOTOMETRY; ISOCAM OBSERVATIONS; VEGA PHENOMENON; AGE-DEPENDENCE AB We report new Spitzer 24 mum photometry of 76 main-sequence A-type stars. We combine these results with previously reported Spitzer 24 mum data and 24 and 25 mum photometry from the Infrared Space Observatory and the Infrared Astronomy Satellite. The result is a sample of 266 stars withmass close to 2.5 M-., all detected to at least the similar to 7 sigma level relative to their photospheric emission. We culled ages for the entire sample from the literature and/or estimated them using the H-R diagram and isochrones; they range from 5 to 850 Myr. We identified excess thermal emission using an internally derived K - 24 ( or 25) mum photospheric color and then compared all stars in the sample to that color. Because we have excluded stars with strong emission lines or extended emission ( associated with nearby interstellar gas), these excesses are likely to be generated by debris disks. Younger stars in the sample exhibit excess thermal emission more frequently and with higher fractional excess than do the older stars. However, as many as 50% of the younger stars do not show excess emission. The decline in the magnitude of excess emission, for those stars that show it, has a roughly t(0)/ time dependence, with t(0) similar to 150 Myr. If anything, stars in binary systems ( including Algoltype stars) and lambda Boo stars show less excess emission than the other members of the sample. Our results indicate that ( 1) there is substantial variety among debris disks, including that a significant number of stars emerge from the protoplanetary stage of evolution with little remaining disk in the 10 - 60 AU region and ( 2) in addition, it is likely that much of the dust we detect is generated episodically by collisions of large planetesimals during the planet accretion end game, and that individual events often dominate the radiometric properties of a debris system. This latter behavior agrees generally with what we know about the evolution of the solar system, and also with theoretical models of planetary system formation. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Jet Prop Lab, Michelson Sci Ctr, Pasadena, CA 91109 USA. RP Rieke, GH (reprint author), Univ Arizona, Steward Observ, 933 N Cherry Ave, Tucson, AZ 85721 USA. RI Stapelfeldt, Karl/D-2721-2012 NR 68 TC 240 Z9 240 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 FEB 20 PY 2005 VL 620 IS 2 BP 1010 EP 1026 DI 10.1086/426937 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DN UT WOS:000227405800041 ER PT J AU McAteer, RTJ Gallagher, PT Brown, DS Bloomfield, DS Moore, R Williams, DR Mathioudakis, M Katsiyannis, A Keenan, FP AF McAteer, RTJ Gallagher, PT Brown, DS Bloomfield, DS Moore, R Williams, DR Mathioudakis, M Katsiyannis, A Keenan, FP TI Observations of H alpha intensity oscillations in a flare ribbon SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : chromosphere; Sun : flares; Sun : magnetic fields; Sun : oscillations; Sun : photosphere ID CORONAL LOOP OSCILLATIONS; HIGH-FREQUENCY OSCILLATIONS; QUASI-PERIODIC PULSATIONS; SOLAR-FLARE; ECLIPSE; REGION; FLUCTUATIONS; WAVES; TRACE AB High-cadence Halpha blue wing observations of a C9.6 solar flare obtained at Big Bear Solar Observatory using the Rapid Dual Imager are presented. Wavelet and time-distance methods were used to study oscillatory power along the ribbon, finding periods of 40 - 80 s during the impulsive phase of the flare. A parametric study found statistically significant intensity oscillations with amplitudes of 3% of the peak flare amplitude, periods of 69 s (14.5 mHz) and oscillation decay times of 500 s. These measured properties are consistent with the existence of flare-induced acoustic waves within the overlying loops. C1 NASA, Goddard Space Flight Ctr, L3 Commun GSI, Greenbelt, MD 20771 USA. Queens Univ Belfast, Dept Pure & Appl Phys, Belfast BT7 1NN, Antrim, North Ireland. Univ St Andrews, Sch Math & Stat, St Andrews KY16 9SS, Fife, Scotland. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Observ Royal Belgique, B-1180 Brussels, Belgium. RP NASA, Goddard Space Flight Ctr, L3 Commun GSI, Greenbelt, MD 20771 USA. EM j.mcateer@grasshopper.gsfc.nasa.gov RI McAteer, R. T. James/D-3736-2011; Williams, David/E-6676-2011; Bloomfield, Shaun/G-5809-2011; Katsiyannis, Thanassis/L-8496-2013; Gallagher, Peter/C-7717-2011 OI Williams, David/0000-0001-9922-8117; Bloomfield, Shaun/0000-0002-4183-9895; Gallagher, Peter/0000-0001-9745-0400 NR 33 TC 20 Z9 20 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 FEB 20 PY 2005 VL 620 IS 2 BP 1101 EP 1106 DI 10.1086/427084 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DN UT WOS:000227405800049 ER PT J AU Ireland, J AF Ireland, J TI Precision limits to emission-line profile measuring experiments SO ASTROPHYSICAL JOURNAL LA English DT Article DE instrumentation : spectrographs; methods : analytical; methods : statistical; Sun : transition region; Sun : UV radiation AB Spectra, such as astrophysical spectra, can provide detailed diagnostics on the state of their emitting volume. Emission-line diagnostics are found by assuming a model for the spectral emission line and then fitting the model to the data. It is shown for Poisson noisy emission-line data, via the application of Cramer-Rao lower bounds, that there are limits to the precision that line fitting can achieve. The limits depend on the spectral line model and the noise properties of the data. A Cramer-Rao lower bound treatment introduces a framework in which questions of line fitting in particular and spectrometers in general may be posed. Some example applications are given and their implications for the design of spectrometric observations are discussed. C1 NASA, Goddard Space Flight Ctr, L3Com Govt Sci Inc, Greenbelt, MD 20771 USA. RP Ireland, J (reprint author), NASA, Goddard Space Flight Ctr, L3Com Govt Sci Inc, Mail Code 682-3,Bldg 26,Room G-1, Greenbelt, MD 20771 USA. EM ireland@cdso8.nascom.nasa.gov NR 12 TC 5 Z9 5 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 FEB 20 PY 2005 VL 620 IS 2 BP 1132 EP 1139 DI 10.1086/427230 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 903DN UT WOS:000227405800052 ER PT J AU Chaston, CC Peticolas, LM Carlson, CW McFadden, JP Mozer, F Wilber, M Parks, GK Hull, A Ergun, RE Strangeway, RJ Andre, M Khotyaintsev, Y Goldstein, ML Acuna, M Lund, EJ Reme, H Dandouras, I Fazakerley, AN Balogh, A AF Chaston, CC Peticolas, LM Carlson, CW McFadden, JP Mozer, F Wilber, M Parks, GK Hull, A Ergun, RE Strangeway, RJ Andre, M Khotyaintsev, Y Goldstein, ML Acuna, M Lund, EJ Reme, H Dandouras, I Fazakerley, AN Balogh, A TI Energy deposition by Alfven waves into the dayside auroral oval: Cluster and FAST observations SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Review ID KELVIN-HELMHOLTZ INSTABILITY; LATITUDE BOUNDARY-LAYER; FIELD LINE RESONANCES; PERIOD MAGNETIC PULSATIONS; SOLAR-WIND VELOCITY; ELECTRON TIME DISPERSION; PC 5 PULSATIONS; SMALL-SCALE; MAGNETOSPHERIC BOUNDARY; GEOMAGNETIC-PULSATIONS AB We report in situ observations from the Cluster and FAST spacecraft showing the deposition of energy into the auroral ionosphere from broadband ULF waves in the cusp and low-latitude boundary layer. A comparison of the wave Poynting flux with particle energy and flux at both satellites indicates that energy transfer from the broadband waves to the plasma occurs through field-aligned electron acceleration, transverse ion acceleration, and Joule heating. These processes are shown to result in precipitating electron fluxes sufficient to drive bright aurora and cause outflows of energized electrons and O+ ions from the ionosphere into the low-latitude boundary layer. By solving an eigenmode equation for Alfven waves in the observed plasma environment, it is shown that the broadband waves observed at Cluster and FAST are dispersive Alfven waves. It is demonstrated that these waves have wavelengths perpendicular to the geomagnetic field extending from significant fractions of an L shell down to ion gyroradii and electron inertial lengths and wave frequencies in the plasma frame from 1 mHz up to 50 mHz. These waves are shown to have wavelengths along the geomagnetic field of the order of the field line length between the ionosphere and the equatorial plane and become field line resonances (FLRs) when on closed field lines. It is shown that the inclusion of nonlinear and/or nonlocal kinetic effects is required in the description of these waves to account for accelerated particles observed. On the basis of the wave polarization and spectral properties observed from Cluster and FAST it is speculated that these waves are generated through the mode conversion of surface Alfven waves driven by tailward flows in the low-latitude boundary layer. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. Swedish Inst Space Phys, Uppsala, Sweden. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ New Hampshire, Durham, NH 03824 USA. CESR, Toulouse, France. Mullard Space Sci Lab, Dorking, Surrey, England. Univ London Imperial Coll Sci & Technol, London, England. RP Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. EM ccc@ssl.berkeley.edu RI Khotyaintsev, Yuri/C-4745-2008; Goldstein, Melvyn/B-1724-2008; OI Dandouras, Iannis/0000-0002-7121-1118; Lund, Eric/0000-0003-1312-9375 NR 128 TC 59 Z9 60 U1 1 U2 14 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 FEB 19 PY 2005 VL 110 IS A2 AR A02211 DI 10.1029/2004JA010483 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 900LE UT WOS:000227215600001 ER PT J AU Moore, TE Fok, MC Chandler, MO Chappell, CR Christon, SP Delcourt, DC Fedder, J Huddleston, M Liemohn, M Peterson, WK Slinker, S AF Moore, TE Fok, MC Chandler, MO Chappell, CR Christon, SP Delcourt, DC Fedder, J Huddleston, M Liemohn, M Peterson, WK Slinker, S TI Plasma sheet and (nonstorm) ring current formation from solar and polar wind sources SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; ENERGETIC ION COMPOSITION; GLOBAL MHD SIMULATION; EARTHS MAGNETOSPHERE; BOUNDARY-LAYER; SATELLITE-OBSERVATIONS; GEOMAGNETIC STORM; MAGNETOPAUSE; IONOSPHERE; ORIGIN AB We consider the formation of the plasma sheet and geosynchronous region (nonstorm) ring current in the framework of collisionless test particle motions in three-dimensional magnetospheric fields obtained from self-consistent MHD simulations. Simulation results are compared with observations of the near-Earth plasma sheet from the Polar spacecraft during 2001 and 2002. Many particles were initiated in two regions representative of the solar wind source upstream of the bow shock and the polar wind source outside the plasmasphere, both of which are dominated by protons (H+). Proton trajectories are run until they precipitate into the atmosphere, escape from the simulation space, or become stably trapped. These calculations produce a database of proton characteristics in each 1 RE 3 volume element of the magnetosphere and yield velocity distributions as well as bulk plasma properties. We report results reflecting steady growth phase conditions after 45 min of southward interplanetary field, B-Z = -5 nT ( B-Y = 0), and for conditions resulting after 2 hours of northward B-Z = +5 nT. The results for simulated velocity distributions are consistent with the Polar soundings of the current sheet from lobe to lobe and with AMPTE/CCE observations of (nonstorm) ring current region protons. The simulations help us identify the differentiation between solar and polar wind H+ ions in observations. The weak NBZ ring current-like pressure is primarily polar wind protons, while the moderately active SBZ ring current-like pressure is primarily solar wind protons. The solar and polar wind contributions to the SBZ ring current are comparable in density, but the solar protons have a higher average energy. For SBZ, solar wind protons enter the nonstorm ring current region primarily via the dawn flank and to a lesser degree via the midnight plasma sheet. For NBZ, solar wind protons enter the ring current-like region via the cusp and flanks. Polar wind protons enter the nonstorm ring current through the midnight plasma sheet in both cases. Solar and ionospheric plasmas thus take different transport paths to the geosynchronous (nonstorm) ring current region and may thus be expected to respond differently to substorm dynamics of the magnetotail. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. NASA, George C Marshall Space Flight Ctr, Natl Space Sci & Technol Ctr, Huntsville, AL USA. Vanderbilt Univ, Nashville, TN USA. Ctr Etudes Environm Terrestre & Planetaires, St Maur, France. George Mason Univ, Vienna, VA USA. Univ Michigan, Ann Arbor, MI 48109 USA. Univ Colorado, Boulder, CO 80309 USA. USN, Res Lab, Washington, DC 20375 USA. RP NASA, Goddard Space Flight Ctr, Greenbelt, MD USA. EM thomas.e.moore@gsfc.nasa.gov RI Moore, Thomas/D-4675-2012; Fok, Mei-Ching/D-1626-2012; Liemohn, Michael/H-8703-2012; Peterson, WK/A-8706-2009; OI Moore, Thomas/0000-0002-3150-1137; Liemohn, Michael/0000-0002-7039-2631; Peterson, WK/0000-0002-1513-6096; Christon, Stephen/0000-0003-1770-2458 NR 55 TC 32 Z9 33 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 19 PY 2005 VL 110 IS A2 AR A02210 DI 10.1029/2004JA010563 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 900LE UT WOS:000227215600002 ER PT J AU Shindell, DT Faluvegi, G Bell, N Schmidt, GA AF Shindell, DT Faluvegi, G Bell, N Schmidt, GA TI An emissions-based view of climate forcing by methane and tropospheric ozone SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GENERAL-CIRCULATION MODEL; GODDARD-INSTITUTE; CHEMISTRY; PHOTOCHEMISTRY; SPACE AB We simulate atmospheric composition changes in response to increased methane and tropospheric ozone precursor emissions from the preindustrial to present-day in a coupled chemistry-aerosol-climate model. The global annual average composition response to all emission changes is within 10% of the sum of the responses to individual emissions types, a more policy-relevant quantity. This small non-linearity between emission types permits attribution of past global mean methane and ozone radiative forcings to specific emissions despite the well-known nonlinear linear response to emissions of a single type. The emissions-based based view indicates that methane emissions have contributed a forcing of similar to0.8 - 0.9 W m(-2), nearly double the abundance-based value, while the forcing from other ozone precursors has been quite small ( similar to-0.1 for NOx, similar to0.2 for CO + VOCs). C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, New York, NY USA. RP Shindell, DT (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM dshindell@giss.nasa.gov RI Shindell, Drew/D-4636-2012; Schmidt, Gavin/D-4427-2012; Unger, Nadine/M-9360-2015 OI Schmidt, Gavin/0000-0002-2258-0486; NR 22 TC 79 Z9 80 U1 0 U2 20 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 FEB 18 PY 2005 VL 32 IS 4 AR L04803 DI 10.1029/2004GL021900 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 900KF UT WOS:000227213100004 ER PT J AU White, MA Hoffman, F Hargrove, WW Nemani, RR AF White, MA Hoffman, F Hargrove, WW Nemani, RR TI A global framework for monitoring phenological responses to climate change SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID VEGETATION INDEX; RESOLUTION; FOOTPRINT; FOREST; AREAS AB Remote sensing of vegetation phenology is an important method with which to monitor terrestrial responses to climate change, but most approaches include signals from multiple forcings, such as mixed phenological signals from multiple biomes, urbanization, political changes, shifts in agricultural practices, and disturbances. Consequently, it is difficult to extract a clear signal from the usually assumed forcing: climate change. Here, using global 8 km 1982 to 1999 Normalized Difference Vegetation Index (NDVI) data and an eight-element monthly climatology, we identified pixels whose wavelet power spectrum was consistently dominated by annual cycles and then created phenologically and climatically self-similar clusters, which we term phenoregions. We then ranked and screened each phenoregion as a function of landcover homogeneity and consistency, evidence of human impacts, and political diversity. Remaining phenoregions represented areas with a minimized probability of non-climatic forcings and form elemental units for long-term phenological monitoring. C1 Utah State Univ, Dept Aquat Watershed & Earth Resources, Logan, UT 84322 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP White, MA (reprint author), Utah State Univ, Dept Aquat Watershed & Earth Resources, Old Main Hall 5240, Logan, UT 84322 USA. EM mikew@cc.usu.edu RI Hoffman, Forrest/B-8667-2012; OI Hoffman, Forrest/0000-0001-5802-4134; White, Michael/0000-0002-0238-8913 NR 21 TC 75 Z9 85 U1 3 U2 36 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 FEB 18 PY 2005 VL 32 IS 4 AR L04705 DI 10.1029/2004GL021961 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 900KF UT WOS:000227213100006 ER PT J AU Xin, X Yan, F Yan, F Alexandrove, P Stahle, CM Hu, J Matsumura, A Li, X Weiner, A Zhao, HJ AF Xin, X Yan, F Yan, F Alexandrove, P Stahle, CM Hu, J Matsumura, A Li, X Weiner, A Zhao, HJ TI Demonstration of 4H-SiC UV single photon counting avalanche photodiode SO ELECTRONICS LETTERS LA English DT Article AB The first 4H-SiC UV single photon counting avalanche photodiode has been designed, fabricated and characterised. Spectral quanturn efficiency from 250 to 370 nm is presented. Single photon counting at room temperature is demonstrated for the first time and counting efficiency is reported. C1 Rutgers State Univ, Dept ECE, SiCLAB, Piscataway, NJ 08854 USA. NASA, Raytheon Co, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. United Silicon Carbide, New Brunswick, NJ 08901 USA. RP Xin, X (reprint author), Rutgers State Univ, Dept ECE, SiCLAB, 94 Brett Rd, Piscataway, NJ 08854 USA. EM jzhao@ece.rutgers.edu RI Sun, Xiaoli/B-5120-2013 NR 5 TC 24 Z9 28 U1 1 U2 4 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 FEB 17 PY 2005 VL 41 IS 4 BP 212 EP 214 DI 10.1049/el:20057320 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA 902VU UT WOS:000227385600034 ER PT J AU Clarke, JT Gerard, JC Grodent, D Wannawichian, S Gustin, J Connerney, J Crary, F Dougherty, M Kurth, W Cowley, SWH Bunce, EJ Hill, T Kim, J AF Clarke, JT Gerard, JC Grodent, D Wannawichian, S Gustin, J Connerney, J Crary, F Dougherty, M Kurth, W Cowley, SWH Bunce, EJ Hill, T Kim, J TI Morphological differences between Saturn's ultraviolet aurorae and those of Earth and Jupiter SO NATURE LA English DT Article ID ALPHA EMISSION; MAGNETOSPHERE; OVAL AB It has often been stated that Saturn's magnetosphere and aurorae are intermediate between those of Earth, where the dominant processes are solar wind driven(1), and those of Jupiter, where processes are driven by a large source of internal plasma(2-4). But this view is based on information about Saturn that is far inferior to what is now available. Here we report ultraviolet images of Saturn, which, when combined with simultaneous Cassini measurements of the solar wind(5) and Saturn kilometric radio emission(6), demonstrate that its aurorae differ morphologically from those of both Earth and Jupiter. Saturn's auroral emissions vary slowly; some features appear in partial corotation whereas others are fixed to the solar wind direction; the auroral oval shifts quickly in latitude; and the aurora is often not centred on the magnetic pole nor closed on itself. In response to a large increase in solar wind dynamic pressure(5) Saturn's aurora brightened dramatically, the brightest auroral emissions moved to higher latitudes, and the dawn side polar regions were filled with intense emissions. The brightening is reminiscent of terrestrial aurorae, but the other two variations are not. Rather than being intermediate between the Earth and Jupiter, Saturn's auroral emissions behave fundamentally differently from those at the other planets. C1 Boston Univ, Boston, MA 02215 USA. Univ Liege, B-4000 Liege, Belgium. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. SW Res Inst, San Antonio, TX 78228 USA. Univ London Imperial Coll Sci Technol & Med, London SW7 2AZ, England. Univ Iowa, Iowa City, IA 52242 USA. Univ Leicester, Leicester LE1 7RH, Leics, England. Rice Univ, Houston, TX 77005 USA. Yonsei Univ, Sch Civil & Environm Engn, Seoul 120749, South Korea. RP Clarke, JT (reprint author), Boston Univ, 725 Commonwealth Ave, Boston, MA 02215 USA. EM jclarke@bu.edu RI Clarke, John/C-8644-2013; connerney, john/I-5127-2013; Bunce, Emma/I-9067-2016; OI Bunce, Emma/0000-0002-9456-0345; Kurth, William/0000-0002-5471-6202; GERARD, Jean-Claude/0000-0002-8565-8746 NR 15 TC 114 Z9 114 U1 0 U2 11 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD FEB 17 PY 2005 VL 433 IS 7027 BP 717 EP 719 DI 10.1038/nature03331 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 897XH UT WOS:000227039200031 PM 15716945 ER PT J AU Kurth, WS Gurnett, DA Clarke, JT Zarka, P Desch, MD Kaiser, ML Cecconi, B Lecacheux, A Farrell, WM Galopeau, P Gerard, JC Grodent, D Prange, R Dougherty, MK Crary, FJ AF Kurth, WS Gurnett, DA Clarke, JT Zarka, P Desch, MD Kaiser, ML Cecconi, B Lecacheux, A Farrell, WM Galopeau, P Gerard, JC Grodent, D Prange, R Dougherty, MK Crary, FJ TI An Earth-like correspondence between Saturn's auroral features and radio emission SO NATURE LA English DT Article ID TERRESTRIAL KILOMETRIC RADIATION; HIGH-FREQUENCY LIMIT; MAGNETIC-FIELD; VOYAGER-1; MODEL AB Saturn is a source of intense kilometre-wavelength radio emissions that are believed to be associated with its polar aurorae(1,2), and which provide an important remote diagnostic of its magnetospheric activity. Previous observations implied that the radio emission originated in the polar regions, and indicated a strong correlation with solar wind dynamic pressure(1,3-7). The radio source also appeared to be fixed near local noon and at the latitude of the ultraviolet aurora(1,2). There have, however, been no observations relating the radio emissions to detailed auroral structures. Here we report measurements of the radio emissions, which, along with high-resolution images of Saturn's ultraviolet auroral emissions(8), suggest that although there are differences in the global morphology of the aurorae, Saturn's radio emissions exhibit an Earth-like correspondence between bright auroral features and the radio emissions. This demonstrates the universality of the mechanism that results in emissions near the electron cyclotron frequency narrowly beamed at large angles to the magnetic field(9,10). C1 Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. Boston Univ, Boston, MA 02215 USA. Observ Paris, Space Res Dept, F-92195 Meudon, France. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. UVSQ, CETP, F-78140 Velizy, Fr Polynesia. Univ Liege, LPAP, B-4000 Liege, Belgium. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. SW Res Inst, San Antonio, TX 78288 USA. RP Kurth, WS (reprint author), Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. EM william-kurth@uiowa.edu RI Clarke, John/C-8644-2013; Farrell, William/I-4865-2013; OI Kurth, William/0000-0002-5471-6202 NR 21 TC 73 Z9 73 U1 0 U2 8 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD FEB 17 PY 2005 VL 433 IS 7027 BP 722 EP 725 DI 10.1038/nature03334 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 897XH UT WOS:000227039200033 PM 15716947 ER PT J AU King, JH Papitashvili, NE AF King, JH Papitashvili, NE TI Solar wind spatial scales in and comparisons of hourly Wind and ACE plasma and magnetic field data SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID SPACECRAFT; PROPAGATION; MONITOR; SWE AB [1] Hourly averaged interplanetary magnetic field ( IMF) and plasma data from the Advanced Composition Explorer ( ACE) and Wind spacecraft, generated from 1 to 4 min resolution data time-shifted to Earth have been analyzed for systematic and random differences. ACE moments-based proton densities are larger than Wind/Solar Wind Experiment (SWE) fits-based densities by up to 18%, depending on solar wind speed. ACE temperatures are less than Wind/SWE temperatures by up to similar to25%. ACE densities and temperatures were normalized to equivalent Wind values in National Space Science Data Center's creation of the OMNI2 data set that contains 1963-2004 solar wind field and plasma data and other data. For times of ACE-Wind transverse separations <60 R-E, random differences between Wind values and normalized ACE values are similar to0.2 nT for \B\, similar to0.45 nT for IMF Cartesian components, similar to5 km/s for flow speed, and similar to15 and similar to30% for proton densities and temperatures. These differences grow as a function of transverse separation more rapidly for IMF parameters than for plasma parameters. Autocorrelation analyses show that spatial scales become progressively shorter for the parameter sequence: flow speed, IMF magnitude, plasma density and temperature, IMF X and Y components, and IMF Z component. IMF variations have shorter scales at solar quiet times than at solar active times, while plasma variations show no equivalent solar cycle dependence. C1 NASA, Goddard Space Flight Ctr, Space Phys Data Facil, Greenbelt, MD 20771 USA. QSS Grp Inc, Lanham, MD USA. RP King, JH (reprint author), NASA, Goddard Space Flight Ctr, Space Phys Data Facil, Mail Code 612-4, Greenbelt, MD 20771 USA. EM jking@mail630.gsfc.nasa.gov; natasha@mail630.gsfc.nasa.gov NR 16 TC 291 Z9 293 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-SPACE JI J. Geophys. Res-Space Phys. PD FEB 16 PY 2005 VL 110 IS A2 AR A02104 DI 10.1029/2004JA010649 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 900LD UT WOS:000227215500001 ER PT J AU Lee, SW von Allmen, P Oyafuso, F Klimeck, G Whaley, KB AF Lee, SW von Allmen, P Oyafuso, F Klimeck, G Whaley, KB TI Effect of electron-nuclear spin interactions for electron-spin qubits localized in InGaAs self-assembled quantum dots SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ATOMIC SCREENING CONSTANTS; EXPERIMENTAL REALIZATION; SEMICONDUCTOR NANOSTRUCTURES; FACTORING ALGORITHM; MAGNETIC-RESONANCE; RAMAN-SCATTERING; ERROR-CORRECTION; SCF FUNCTIONS; SITE CONTROL; INAS DOTS AB The effect of electron-nuclear spin interactions on qubit operations is investigated for a qubit represented by the spin of an electron localized in an InGaAs self-assembled quantum dot. The localized electron wave function is evaluated within the atomistic tight-binding model. The electron Zeeman splitting induced by the electron-nuclear spin interaction is estimated in the presence of an inhomogeneous environment characterized by a random nuclear spin configuration, by the dot-size distribution, alloy disorder, and interface disorder. Due to these inhomogeneities, the electron Zeeman splitting varies from one qubit to another by the order of 10(-6), 10(-6), 10(-7), and 10(-9) eV, respectively. Such fluctuations cause errors in exchange operations due to the inequality of the Zeeman splitting between two qubits. However, the error can be made lower than the quantum error threshold if an exchange energy larger than 10(-4) eV is used for the operation. This result shows that the electron-nuclear spin interaction does not hinder quantum-dot based quantum computer architectures from being scalable even in the presence of inhomogeneous environments. (C) 2005 American Institute of Physics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM seungwon.lee@jpl.nasa.gov RI Klimeck, Gerhard/A-1414-2012 OI Klimeck, Gerhard/0000-0001-7128-773X NR 81 TC 17 Z9 17 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD FEB 15 PY 2005 VL 97 IS 4 AR 043706 DI 10.1063/1.1850605 PG 8 WC Physics, Applied SC Physics GA 895DU UT WOS:000226841900048 ER PT J AU Chernov, AA Rashkovich, LN Vekilov, PG AF Chernov, AA Rashkovich, LN Vekilov, PG TI Steps in solution growth: dynamics of kinks, bunching and turbulence SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 12th International Summer School of Crystal Growth held in Conjunction with the 14th International Conference on Crystal Growth CY AUG 09-13, 2004 CL Grenoble, FRANCE SP French Assoc Crystal Growth DE biocrystallization; diffusion; fluid flows; morphological stability; surface processes ID PHASE-SHIFTING INTERFEROMETRY; CALCIUM-OXALATE MONOHYDRATE; CRYSTAL-GROWTH; MORPHOLOGICAL STABILITY; VICINAL FACE; KINETICS; CRYSTALLIZATION; INTERFACE; FLOW; KDP AB New findings on calcium oxalate monohydrate, monoclinic lysozyme and potassium dihydrophosphate crystal growth are presented and discussed. Atomic force microscopy was applied to measure step rates on CaOx and monoclinic lysozyme faces to understand kink kinetics. High precision Michaelson interferometry allowed to discover step splitting on the (1 0 1) KH(2)PO(4) face growing from turbulent solution. In all three cases, aqueous solutions at room temperature were used. CaOx was grown from solution in which the ion concentration ratio xi = [Ox]/[Ca] = 5 x 10(-2), 10(-1), 1, 10, 20. The rate v of steps one lattice spacing high on the (1 0 0) face reach maximum at xi = 1. Attachment and detachment statistics of two types of particles (Ca and Ox) to a kink on the step of a non-Kossel crystal predicted the reciprocal kink propagation rate to be 1/v similar to xi(1/2) + xi(-1/2), consistent with experiment. Step morphology on the (1 0 1) face of monoclinic lysozyme suggests rhombic, about rectangular 2D critical nucleus. In such a nucleus, two mutually parallel, though crystallographically different steps making the opposite edges, are supposed to be equal. The segment lengths pinned at dislocation outcrop are found to be very different and experience huge scattering. These phenomena, treated as a result of different kink nucleation rates on parallel nearly kink-free steps "looking" to the opposite directions, are of kinetic rather than of thermodynamic origin. Contrary to conventional observations, in a turbulent solution flow the average step bunch width and height were found to reach limits as bunches propagate along the face. These limits decrease when the flow rate increases from similar to 60 to 200 cm/s. The phenomenon is explained by the turbulent nature of the solution flow. In this flow, due to penetration of turbulent eddies, diffusivity within the viscous solution boundary layer, D = D(0) + 0.5 u(tau) y, quickly increases with the distance y from the interface since the friction velocity, u(tau) , reaches several cm/s. Therefore, molecular diffusivity, D(0) congruent to 10(-5) cm(2)/s, is significant only within the similar to 20-40 nm thick solution layer over the interface. As the flow rate increases, the turbulent mixed solution approaches the growing stepped crystal face closer and shrinks the range within which steps interact with one another through their diffusion fields. This weak interaction results in step splitting. (c) 2004 Elsevier B.V. All rights reserved. C1 NASA Marshall Space Flight Ctr, BAE Syst Analyt Solut Inc, Huntsville, AL 35806 USA. Moscow MV Lomonosov State Univ, Dept Phys, Moscow 119992, Russia. Univ Houston, Dept Chem Engn, Houston, TX 77204 USA. RP Chernov, AA (reprint author), NASA Marshall Space Flight Ctr, BAE Syst Analyt Solut Inc, 4950 Corp Dr,Ste 100, Huntsville, AL 35806 USA. EM alex.chernov@msfc.nasa.gov NR 47 TC 43 Z9 46 U1 2 U2 20 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 FEB 15 PY 2005 VL 275 IS 1-2 BP 1 EP 18 DI 10.1016/j.jcrysgro.2004.10.094 PG 18 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 913JU UT WOS:000228148600002 ER PT J AU Kimura, Y Ishikawa, M Kurumada, M Tanigaki, T Suzuki, H Kaito, C AF Kimura, Y. Ishikawa, M. Kurumada, M. Tanigaki, T. Suzuki, H. Kaito, C. TI Crystal structure and growth of carbon-silicon mixture film prepared by ion sputtering SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE Crystal structure; Nanostructures; Diamonds AB Si (10-50%)-containing carbon (C-Si) films were prepared by ion sputtering of carbon and silicon carbide mixture pellets. The C-Si film was composed of a solid-solution phase of carbon and silicon with a diamond structure. The film showed a higher transparency than a simultaneously evaporated C-Si mixture film. Diamond crystals 100 nm in diameter were also produced by vacuum heating of C-Si film at 800 degrees C: The infrared spectrum showed significant absorption features at 9.5 and 21 mu m; in contrast to the 11 and 12 mm of SiC. The 21 mu m feature is one of the candidate unidentified infrared bands on the spectra of carbon-rich post-asymptotic giant branch stars. (C) 2004 Elsevier B.V. All rights reserved. C1 [Kimura, Y.; Ishikawa, M.; Kurumada, M.; Tanigaki, T.; Suzuki, H.; Kaito, C.] Ritsumeikan Univ, Dept Phys, Kusatsu, Shiga 5258577, Japan. RP Kimura, Y (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Code 691, Greenbelt, MD 20771 USA. EM rp092955@se.ritsumei.ac.jp RI Kimura, Yuki/J-9635-2014 OI Kimura, Yuki/0000-0002-9218-7663 NR 7 TC 1 Z9 1 U1 0 U2 0 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 FEB 15 PY 2005 VL 275 IS 1-2 BP E977 EP E981 DI 10.1016/j.jcrysgro.2004.11.151 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA V23DX UT WOS:000208324600160 ER PT J AU Jensen, E Pfister, L Bui, T Weinheimer, A Weinstock, E Smith, J Pittman, J Baumgardner, D Lawson, P McGill, MJ AF Jensen, E Pfister, L Bui, T Weinheimer, A Weinstock, E Smith, J Pittman, J Baumgardner, D Lawson, P McGill, MJ TI Formation of a tropopause cirrus layer observed over Florida during CRYSTAL-FACE SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID TROPICAL TROPOPAUSE; UPPER TROPOSPHERE; ICE NUCLEATION; CLOUDS; TRANSPORT; AEROSOLS; TEMPERATURE; AIRCRAFT; LIDAR AB [1] On 13 July 2002 a widespread, subvisible tropopause cirrus layer occurred over the Florida region. This cloud was observed in great detail with the NASA Cirrus Regional Study of Tropical Anvils and Cirrus Layers-Florida Area Cirrus Experiment (CRYSTAL-FACE) instrumentation, including in situ measurements with the WB-57 aircraft. In this paper, we use the 13 July cloud as a case study to evaluate the physical processes controlling the formation and evolution of tropopause cirrus layers. Microphysics measurements indicate that ice crystal diameters in the cloud layer ranged from about 7 to 50 mm, and the peak number mode was about 10-25 mum. In situ water vapor and temperature measurements in the cloud indicated supersaturation with respect to ice throughout, with ice saturation ratios as large as 1.8. Even when the ice surface area density was as high as about 500 mum(2) cm(-3), ice supersaturations of 20-30% were observed. Trajectory analysis shows that the air sampled near the tropopause on this day generally came from the north and cooled considerably during the previous few days. Examination of infrared satellite imagery along air parcel back trajectories from the WB-57 flight track indicates that the tropopause cloud layer formation was, in general, not simply left over ice from recently generated anvil cirrus. Simulations of cloud formation using time-height curtains of temperature along the trajectory paths show that the cloud could have formed in situ near the tropopause as the air was advected into the south Florida region and cooled to unusually low temperatures. If we assume a high threshold for ice nucleation via homogeneous freezing of aqueous sulfate aerosols, the model reproduces the observed cloud structure, ice crystal size distributions, and ice supersaturation statistics. Inclusion of observed gravity wave temperature perturbations in the simulations is essential to reproduce the observed cloud properties. Without waves, crystal number densities are too low, crystal sizes are too large, and the crystals fall out too fast, leaving very little cloud persisting at the end of the simulations. In the cloud simulations, coincidence of high supersaturations and high surface areas can be produced by either recent nucleation or sedimentation of crystals into supersaturated layers. The agreement between model results and observed supersaturations is improved somewhat if we assume that the steady state relative humidity within cirrus at T < 200 K is enhanced by about 30%. The WB-57 measurements and the model results suggest that the cloud layer irreversibly dehydrated air near the tropopause. C1 Univ Nacl Autonoma Mexico, Ctr Ciencias Atmosfera, Mexico City 04510, DF, Mexico. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Spec Inc, Boulder, CO 80301 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA. Natl Ctr Atmospher Res, Atmospher Chem Div, Boulder, CO 80307 USA. RP Univ Nacl Autonoma Mexico, Ctr Ciencias Atmosfera, Mexico City 04510, DF, Mexico. EM ejensen@sky.arc.nasa.gov; wein@ncar.ucar.edu; elliot@huarp.harvard.edu; darrel@servidor.unam.mx; plawson@specinc.com; matthew.j.mcgill@nasa.gov RI McGill, Matthew/D-8176-2012 NR 24 TC 150 Z9 150 U1 6 U2 12 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 FEB 15 PY 2005 VL 110 IS D3 AR D03208 DI 10.1029/2004JD004671 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 900KL UT WOS:000227213700001 ER PT J AU Hepp, AF AF Hepp, AF TI Special issue - Thin films and nanomaterials for energy conversion and storage - Editorial and dedication SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Editorial Material C1 NASA Glenn Res Ctr, Thin Film Technol Grp, Cleveland, OH 44135 USA. RP Hepp, AF (reprint author), NASA Glenn Res Ctr, Thin Film Technol Grp, Lewis Field,21000 Brookpk Rd,MS 302-1, Cleveland, OH 44135 USA. EM aloysius.f.hepp@nasa.gov NR 0 TC 0 Z9 0 U1 0 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD FEB 15 PY 2005 VL 116 IS 3 BP 231 EP 231 DI 10.1016/j.mseb.2004.10.008 PG 1 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 898DO UT WOS:000227056500001 ER PT J AU Raffaelle, RP Landi, BJ Harris, JD Bailey, SG Hepp, AF AF Raffaelle, RP Landi, BJ Harris, JD Bailey, SG Hepp, AF TI Carbon nanotubes for power applications SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 3rd Conference on Thin Films and Nanomaterials for Energy Conversion and Storage CY SEP, 2003 CL Ohio Aerosp Inst, Cleveland, OH HO Ohio Aerosp Inst DE SWNT; MWNT; fuel cell; battery; solar cell; thermionic ID POLYMER PHOTOVOLTAIC DEVICES; FIELD-EMISSION; AMIDE SOLVENTS; SINGLE; DEPOSITION; BUNDLES; GROWTH; MODES; PURIFICATION; ACTUATORS AB Carbon nanotubes have been found to possess a wide variety of extremely remarkable properties, most notably high electrical and thermal conductivity, mechanical strength, and catalytic surface area. These properties imbue carbon nanotubes with tremendous Potential for a variety of power generation and storage devices including: lithium-ion (Li+) batteries, polymeric solar cells, proton exchange membrane (PEM) fuel cells, and thermionic power devices. A review of the key issues surrounding synthesis, characterization, and processing of carbon nanotubes in relation to device fabrication will be highlighted. Results on a variety of prototype devices which are being developed by the NanoPower Research Laboratories (NPRL) at RIT in collaboration with researchers at the NASA Glenn Research Center will be presented. (C) 2004 Elsevier B.V. All rights reserved. C1 Rochester Inst Technol, NPRL, Rochester, NY 14623 USA. NASA Glenn Res Ctr, Cleveland, OH 44135 USA. RP Raffaelle, RP (reprint author), Rochester Inst Technol, NPRL, Rochester, NY 14623 USA. EM rprsps@fit.edu NR 55 TC 141 Z9 148 U1 5 U2 35 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD FEB 15 PY 2005 VL 116 IS 3 BP 233 EP 243 DI 10.1016/j.mseb.2004.09.034 PG 11 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 898DO UT WOS:000227056500002 ER PT J AU Walters, RJ Garner, JC Lam, SN Vasquez, JA Braun, WR Ruth, RE Messenger, SR Lorentzen, JR Bruninga, R Jenkins, PP Flatico, JM Wilt, DM Piszczor, MF Greer, LC Krasowski, MJ AF Walters, RJ Garner, JC Lam, SN Vasquez, JA Braun, WR Ruth, RE Messenger, SR Lorentzen, JR Bruninga, R Jenkins, PP Flatico, JM Wilt, DM Piszczor, MF Greer, LC Krasowski, MJ TI Materials on the International Space Station - forward technology solar cell experiment SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 3rd Conference on Thin Films and Nanomaterials for Energy Conversion and Storage CY SEP, 2003 CL Ohio Aerosp Inst, Cleveland, OH HO Ohio Aerosp Inst DE solar cells; thin films; chalcopyrite AB This paper describes the forward technology solar cell experiment (FTSCE), which is a space experiment built by the Naval Research Laboratory (NRL) in collaboration with NASA Glenn Research Center (GRC), and the US Naval Academy (USNA) as part of the materials on the International Space Station (MISSE) program. The goal is to rapidly put current and future generation space solar cells on orbit and provide validation data for these technologies. Telemetry, command, control, and communication (TNC) for the FTSCE will be achieved through the Amateur Satellite Service using the PCSat2 system, which is an Amateur Radio system designed and built by the USNA. In addition to providing an off-the-shelf solution for FTSCE TNC, PCSat2 will provide a communications node for the Amateur Radio satellite system. The FTSCE and PCSat2 will be housed within the passive experiment container (PEC), which is an approximately 2 ft x 2 ft x 4 in. metal container built by NASA Langley Research Center (NASA LaRC) as part of the MISSE program. NASA LaRC has also supplied a thin film materials experiment that will fly on the exterior of the thermal blanket covering the PCSat2. The PEC is planned to be transported to the ISS on a Shuttle flight. The PEC will be mounted on the exterior of the ISS by an astronaut during an extravehicular activity (EVA). After nominally 1 year, the PEC will be retrieved and returned to Earth. This paper presents the design of the experiment, the electrical data measured on the experiment solar cells, and the results of environmental testing of the system. Published by Elsevier B.V. C1 USN, Res Lab, Washington, DC 20375 USA. USN, Res Lab, Washington, DC 20375 USA. SFA Inc, Largo, MD 20774 USA. USN Acad, Annapolis, MD 21402 USA. Ohio Aerosp Inst, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Cleveland, OH 44135 USA. QSS, Cleveland, OH 44135 USA. NASA Glenn Res Ctr, Cleveland, OH 44135 USA. RP Walters, RJ (reprint author), USN, Res Lab, Code 6818 4555 Overlook Ave SW, Washington, DC 20375 USA. EM Robert.Walters@nrl.navy.mil NR 0 TC 8 Z9 8 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD FEB 15 PY 2005 VL 116 IS 3 BP 257 EP 263 DI 10.1016/j.mseb.2004.06.025 PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 898DO UT WOS:000227056500005 ER PT J AU Simburger, EJ Matsumoto, JH Giants, TW Garcia, A Liu, S Rawal, SP Perry, AR Marshall, CH Lin, JK Scarborough, SE Curtis, HB Kerslake, TW Peterson, TT AF Simburger, EJ Matsumoto, JH Giants, TW Garcia, A Liu, S Rawal, SP Perry, AR Marshall, CH Lin, JK Scarborough, SE Curtis, HB Kerslake, TW Peterson, TT TI Thin-film technology development for the PowerSphere SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 3rd Conference on Thin Films and Nanomaterials for Energy Conversion and Storage CY SEP, 2003 CL Ohio Aerosp Inst, Cleveland, OH HO Ohio Aerosp Inst DE microsatellite; thin-film solar cells; UV-rigidizable structures; inflatable AB The PowerSphere concept consists of a relatively large spherical solar array, which would be deployed from a microsatellite. The PowerSphere will enable microsatellite missions across NASA enterprises and DoD missions by providing ample electric power at an affordable cost. The PowerSphere design provides attitude-independent electric power and thermal control for an enclosed microsatellite payload. The specific power design is scalable, robust in high radiation environments and provides sufficient electric power to allow the use of electric propulsion. Electric propulsion enables precise positioning of microsatellites, which is required for inspectors that would be deployed to observe the International Space Station, Space Shuttle or large unmanned spacecraft. Published by Elsevier B.V. C1 Aerosp Corp, El Segundo, CA 90245 USA. Lockheed Martin Space Syst Co, Denver, CO 80125 USA. ILC Dover Inc, Dover, DE 19946 USA. NASA Glenn Res Ctr, Cleveland, OH 44135 USA. RP Simburger, EJ (reprint author), Aerosp Corp, El Segundo, CA 90245 USA. EM edward.j.simburger@aero.org NR 16 TC 6 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD FEB 15 PY 2005 VL 116 IS 3 BP 265 EP 272 DI 10.1016/j.mseb.2004.09.035 PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 898DO UT WOS:000227056500006 ER PT J AU Maranchi, JP Hepp, AF Kumta, PN AF Maranchi, JP Hepp, AF Kumta, PN TI LiCoO2 and SnO2 thin battery applications film electrodes for lithium-ion battery applications SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 3rd Conference on Thin Films and Nanomaterials for Energy Conversion and Storage CY SEP, 2003 CL Ohio Aerosp Inst, Cleveland, OH HO Ohio Aerosp Inst DE LiCoO2; SnO2; spin coating; microstructure; thin film battery; economical ID SOL-GEL METHOD; FABRICATION; CATHODES; MICROBATTERY AB There is an increasing need for small-dimension, ultra-lightweight, portable power supplies due to the miniaturization of consumer electronic devices. Rechargeable thin film lithium-ion batteries have the potential to fulfill the growing demands for micro-energy storage devices. However, rechargeable battery technology and fabrication processes have not kept pace with the advances made in device technology. Economical fabrication methods lending excellent microstructural and compositional control in the thin film battery electrodes have yet to be fully developed. In this study, spin coating has been used to demonstrate the flexibility of the approach to produce both anode (SnO2) and cathode (LiCoO2) thin films. Results on the microstructure, crystal structure, and electrochemical properties of the thin film electrodes are described and discussed. (C) 2004 Elsevier B.V. All rights reserved. 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 Kumta, PN (reprint author), Carnegie Mellon Univ, Dept Mat Sci & Engn, 4309 Wean Hall, Pittsburgh, PA 15213 USA. EM kumta@cmu.edu NR 21 TC 23 Z9 26 U1 1 U2 15 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD FEB 15 PY 2005 VL 116 IS 3 BP 327 EP 340 DI 10.1016/j.mseb.2004.05.041 PG 14 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 898DO UT WOS:000227056500015 ER PT J AU Harris, JD Raffaelle, RP Gennett, T Landi, BJ Hepp, AE AF Harris, JD Raffaelle, RP Gennett, T Landi, BJ Hepp, AE TI Growth of multi-walled carbon nanotubes by injection CVD using cyclopentadienyliron dicarbonyl dimer and cyclooctatetraene iron tricarbonyl SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 3rd Conference on Thin Films and Nanomaterials for Energy Conversion and Storage CY SEP, 2003 CL Ohio Aerosp Inst, Cleveland, OH HO Ohio Aerosp Inst DE carbon nanotubes; chemical vapor deposition; catalyst; TGA; Raman ID CHEMICAL-VAPOR-DEPOSITION; SINGLE-SOURCE PRECURSORS; ALIGNED CARBON; PYROLYSIS; FILMS; TEMPERATURE; BUNDLES; DIAMETER; STRANDS; YIELD AB Preferential oriented multi-walled carbon nanotubes were prepared by injection chemical vapor deposition (CVD) using either cyclopentadienyliron dicarbonyl dimer or cyclooctatetraene iron tricarbonyl as the iron catalyst source. The catalyst precursors were dissolved in toluene as the carrier solvent for the injections. The concentration of the catalyst was found to influence both the growth (i.e., MWNT orientation) of the nanotubes, as well as the amount of iron in the deposited material. As deposited, the multi-walled carbon nanotubes contained as little as 2.8 wt.% of iron. The material was deposited onto tantalum foil and fused silica substrates. The nanotubes were characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and thermogravimetric analysis. This synthetic route provides a simple and scalable method to deposit MWNTs with a low defect density, low metal content and a preferred orientation. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Glenn Res Ctr, Thin Film Technol Grp, Cleveland, OH 44135 USA. NW Nazarene Univ, Dept Chem, Nampa, ID 83686 USA. Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. Rochester Inst Technol, Dept Phys, Rochester, NY 14623 USA. Rochester Inst Technol, Dept Chem, Rochester, NY 14623 USA. Rochester Inst Technol, Nanopower Res Lab, Rochester, NY 14623 USA. RP Harris, JD (reprint author), NASA, Glenn Res Ctr, Thin Film Technol Grp, Cleveland, OH 44135 USA. EM jdharris@nnu.edu; aloysius.f.hepp@nasa.gov NR 37 TC 26 Z9 26 U1 0 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD FEB 15 PY 2005 VL 116 IS 3 BP 369 EP 374 DI 10.1016/j.mseb.2004.06.023 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 898DO UT WOS:000227056500021 ER PT J AU Hehemann, DG Lau, JE Harris, JD Hoops, MD Duffy, NV Fanwick, PE Khan, O Jin, MHC Hepp, AF AF Hehemann, DG Lau, JE Harris, JD Hoops, MD Duffy, NV Fanwick, PE Khan, O Jin, MHC Hepp, AF TI Synthesis, characterization and decomposition studies of tris(N,N-dibenzyldithiocarbamato)indium(III): chemical spray deposition of polycrystalline CuInS2 on copper films SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 3rd Conference on Thin Films and Nanomaterials for Energy Conversion and Storage CY SEP, 2003 CL Ohio Aerosp Inst, Cleveland, OH HO Ohio Aerosp Inst DE In2S3; solar cells; thin film; TGA; spray CVD; crystal structure ID SINGLE-SOURCE PRECURSORS; SOLAR-CELLS; CRYSTAL AB Tris(bis(phenylmethyl)carbamodithioato-S,S'), commonly referred to as tris(N,N-dibenzyldithiocarbamato)indium(III), In(S(2)CNBz(2))(3), was synthesized and characterized by single crystal X-ray crystallography. The compound crystallizes in the triclinic space group P (1) over bar with two molecules per unit cell. The material was further characterized using a novel analytical system employing the combined powers of thermogravimetric analysis, gas chromatography/mass spectrometry, and Fourier transform infrared (FT-IR) spectroscopy to investigate its potential use as a precursor for the chemical vapor deposition (CVD) of thin film materials for photovoltaic applications. Upon heating, the material thermally decomposes to release CS2 and benzyl moieties in to the gas phase, resulting in bulk In2S3. Preliminary spray CVD experiments indicate that In(S(2)CNBz(2))(3) decomposed on a Cu substrate reacts to produce stoichiometric CuInS2 films. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, Glenn Res Ctr, Thin Film Technol Grp, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Brookpark, OH 44142 USA. NW Nazarene Univ, Dept Chem, Nampa, ID 83686 USA. Wheeling Jesuit Univ, Dept Chem, Wheeling, WV 26003 USA. Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA. RP Duffy, NV (reprint author), NASA, Glenn Res Ctr, Thin Film Technol Grp, Cleveland, OH 44135 USA. EM nduffy@wju.edu; aloysius.f.hepp@nasa.gov RI Fanwick, Phillip/A-8625-2009 NR 22 TC 10 Z9 10 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD FEB 15 PY 2005 VL 116 IS 3 BP 381 EP 389 DI 10.1016/j.mseb.2004.08.016 PG 9 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 898DO UT WOS:000227056500023 ER PT J AU Jin, MHC Banger, KK Harris, JD Hepp, AF AF Jin, MHC Banger, KK Harris, JD Hepp, AF TI CuInS2 films deposited by aerosol-assisted chemical vapor deposition using ternary single-source precursors SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 3rd Conference on Thin Films and Nanomaterials for Energy Conversion and Storage CY SEP, 2003 CL Ohio Aerosp Inst, Cleveland, OH HO Ohio Aerosp Inst DE CuInS2; single-source precursor; chemical vapor deposition ID ULTRASONIC SPRAY-PYROLYSIS; THIN-FILMS; SOLAR-CELLS; OPTICAL-PROPERTIES; GROWTH; MICROSTRUCTURE; DESIGN; POWDER AB Polycrystalline CuInS2 films were deposited by aerosol-assisted chemical vapor deposition using both solid and liquid ternary single-source precursors (SSPs) prepared in-house. Films with either (112) or (204/220) preferred orientation were obtained, and compositional analysis showed that (112)-oriented films contained more copper than (204/220)-oriented films. Using X-ray diffraction, the signature of chalcopyrite structure was often confirmed for (112)-oriented films. The preferred orientation of the film is likely related to the decomposition and reaction kinetics associated with the molecular structure of the precursors at the substrate. Interestingly, the (204/220)-oriented films were always accompanied by a secondary phase, which was identified as an unknown In-rich compound from the results of post-growth annealing, etching experiments, and Raman spectroscopic data. By increasing Cu to In ratio in the film, (112)-oriented films were obtained with a maximum grain size of about 0.5 mum, and their X-ray diffraction did not show any observable signature of the In secondary phase. Electrical and optical properties of all the films grown were characterized. They all showed p-type conduction with an electrical resistivity between 0.1 Omega cm and 30 Omega cm, and an optical band gap of 1.46 eV +/- 0.02, as deposited. The material properties of deposited films revealed this methodology of using SSPs for fabricating chalcopyrite-based solar cells to be highly promising. Published by Elsevier B.V. C1 NASA, Glenn Res Ctr, Photovolta & Space Environm Branch, Cleveland, OH 44135 USA. NW Nazarene Univ, Dept Chem, Nampa, ID 83686 USA. Ohio Aerosp Inst, Brookpark, OH 44142 USA. RP Jin, MHC (reprint author), NASA, Glenn Res Ctr, Photovolta & Space Environm Branch, Cleveland, OH 44135 USA. EM michael.h.jin@grc.nasa.gov; aloysius.f.hepp@nasa.gov NR 42 TC 14 Z9 15 U1 1 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD FEB 15 PY 2005 VL 116 IS 3 BP 395 EP 401 DI 10.1016/j.mseb.2004.05.043 PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 898DO UT WOS:000227056500025 ER PT J AU Kelly, CV Jin, MHC Banger, KK McNatt, JS Dickman, JE Hepp, AF AF Kelly, CV Jin, MHC Banger, KK McNatt, JS Dickman, JE Hepp, AF TI Parametric study on non-vacuum chemical vapor deposition of CuInS2 from a single-source precursor SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 3rd Conference on Thin Films and Nanomaterials for Energy Conversion and Storage CY SEP, 2003 CL Ohio Aerosp Inst, Cleveland, OH HO Ohio Aerosp Inst DE CuInS2; single-source precursor; chemical vapor deposition ID THIN-FILM; SOLAR-CELLS; MICROSTRUCTURE AB Copper indium disulfide (CuInS2) films were deposited by aerosol-assisted chemical vapor deposition (AACVD) from a single-source precursor (SSP), (PPh3)(2)Cu(SEt)(2)In(SEt)(2). Various deposition parameters were explored to understand how they affect the crystallography, stoichiometry, and morphology of the deposited films and the quality of fabricated solar cells. Parameters explored included the deposition temperature, location of substrate within CVD reactor, precursor concentration in toluene carrier solvent, and post-deposition annealing in a S-rich atmosphere. CuInS2 films have been fabricated into complete solar cells with the top-down composition of Al/ZnO:F/CdS/CuInS2/Mo/glass and the efficiency of 1.0% under simulated AM0 illumination. Published by Elsevier B.V. C1 NASA, Glenn Res Ctr, Photovolt & Space Environm Branch, Cleveland, OH 44135 USA. Ohio Aerosp Inst, Brookpark, OH 44142 USA. RP Jin, MHC (reprint author), NASA, Glenn Res Ctr, Photovolt & Space Environm Branch, Cleveland, OH 44135 USA. EM michael.h.jin@grc.nasa.gov; aloysius.f.hepp@nasa.gov RI Kelly, Christopher/J-1206-2014 OI Kelly, Christopher/0000-0003-0886-8691 NR 20 TC 7 Z9 7 U1 1 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD FEB 15 PY 2005 VL 116 IS 3 BP 403 EP 408 DI 10.1016/j.mseb.2004.09.033 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 898DO UT WOS:000227056500026 ER PT J AU Cozmuta, I O'Keeffe, JT Bose, D Stolc, V AF Cozmuta, I O'Keeffe, JT Bose, D Stolc, V TI Hybrid MD-Nernst Planck model of alpha-hemolysin conductance properties SO MOLECULAR SIMULATION LA English DT Article DE ionic current; alpha-hemolysin; molecular dynamics; Poisson-Nernst-Planck theory; ion channel; conductance ID MOLECULAR-DYNAMICS; ION-CHANNEL; DIELECTRIC-CONSTANTS; BROWNIAN DYNAMICS; NUCLEIC-ACIDS; PERMEATION; WATER; PORE; DISCRIMINATION; COEFFICIENTS AB Motivated by experiments in which an applied electric field translocates polynucleotides through an alpha-hemolysin protein channel causing ionic current transient blockade, a hybrid simulation model is proposed to predict the conductance properties of the open channel. Time scales corresponding to ion permeation processes are reached using the Poisson-Nernst-Planck (PNP) electro-diffusion model in which both solvent and local ion concentrations are represented as a continuum. The diffusion coefficients of the ions (K+ and Cl-) input in the PNP model are, however, calculated from all-atom molecular dynamics (MD). In the MD simulations, a reduced representation of the channel is used. The channel is solvated in a 1 M KCl solution, and an external electric field is applied. The pore specific diffusion coefficients for both ionic species are reduced 5-7 times in comparison to bulk values. Significant statistical variations (17-45%) of the pore-ions diffusivities are observed. Within the statistics, the ionic diffusivities remain invariable for a range of external applied voltages between 30 and 240 mV. In the 2D-PNP calculations, the pore stem is approximated by a smooth cylinder of radius similar to9 Angstrom with two constriction blocks where the radius is reduced to similar to6 Angstrom. The electrostatic potential includes the contribution from the atomistic charges. The MD-PNP model shows that the atomic charges are responsible for the rectifying behaviour and for the slight anion selectivity of the alpha-hemolysin pore. Independent of the hierarchy between the anion and cation diffusivities, the anionic contribution to the total ionic current will dominate. The predictions of the MD-PNP model are in good agreement with experimental data and give confidence in the present approach of bridging time scales by combining a microscopic and macroscopic model. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Eloret Corp, Moffett Field, CA USA. RP Stolc, V (reprint author), NASA, Ames Res Ctr, Mail Stop 239-11, Moffett Field, CA 94035 USA. EM vstolc@mail.arc.nasa.gov NR 48 TC 16 Z9 17 U1 1 U2 3 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0892-7022 J9 MOL SIMULAT JI Mol. Simul. PD FEB 15 PY 2005 VL 31 IS 2-3 BP 79 EP 93 DI 10.1080/08927020412331308467 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 886CH UT WOS:000226203800003 ER PT J AU Evans, DL Alpers, W Cazenave, A Elachi, C Farr, T Glackin, D Holt, B Jones, L Liu, WT McCandless, W Menard, Y Moore, R Njoku, E AF Evans, DL Alpers, W Cazenave, A Elachi, C Farr, T Glackin, D Holt, B Jones, L Liu, WT McCandless, W Menard, Y Moore, R Njoku, E TI Seasat - A 25-year legacy of success SO REMOTE SENSING OF ENVIRONMENT LA English DT Review DE Seasat; Scanning Multichannel Microwave Radiometer; synthetic aperture radar ID SYNTHETIC-APERTURE RADAR; MULTICHANNEL MICROWAVE RADIOMETER; A SATELLITE SCATTEROMETER; SHUTTLE IMAGING RADAR; ANTARCTIC ICE-SHEET; SIR-C/X-SAR; ERS WIND SCATTEROMETER; OCEAN SURFACE; SOIL-MOISTURE; EASTERN SAHARA AB Thousands of scientific publications and dozens of textbooks include data from instruments derived from NASA's Seasat. The Seasat mission was launched on June 26, 1978, on an Atlas-Agena rocket from Vandenberg Air Force Base. It was the first Earth-orbiting satellite to carry four complementary microwave experitnents-the Radar Altimeter (ALT) to measure ocean surface topography by measuring spacecraft altitude above the ocean surface; the Seasat-A Satellite Scatterometer (SASS), to measure wind speed and direction over the ocean; the Scanning Multichannel Microwave Radiometer (SMMR) to measure surface wind speed, ocean surface temperature, atmospheric water vapor content, rain rate, and ice coverage; and the Synthetic Aperture Radar (SAR), to image the ocean surface, polar ice caps, and coastal regions. While originally designed for remote sensing of the Earth's oceans, the legacy of Seasat has had a profound impact in many other areas including solid earth science, hydrology, ecology and planetary science. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Hamburg, Inst Meereskunde, D-22529 Hamburg, Germany. Ctr Natl Etud Spatiales, Lab Etudes Geophys & Oceanog Spatiales, F-31401 Toulouse, France. Aerosp Corp, Los Angeles, CA 90009 USA. Univ Cent Florida, Cent Florida Remote Sensing Lab, Orlando, FL 32816 USA. User Syst Enterprises, Denver, CO 80220 USA. Ctr Natl Etud Spatiales, F-31401 Toulouse, France. Univ Kansas, Lawrence, KS 66047 USA. RP Evans, DL (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM diane.evans@jpl.nasa.gov; alpers@ifm.uni-hamburg.de; anny.casenave@cnes.fr; charles.elachi@jpl.nasa.gov; tom.farr@jpl.nasa.gov; David.L.Glackin@aero.org; ben@pacific.jpl.nasa.gov; ljones@pegasus.cc.ucf.edu; liu@pacifie.jpl.nasa.gov; waltmc@usersystems.com; yves.menard@cnes.fr; rmoore@sunflower.com; eni.njoku@jpl.nasa.gov OI Farr, Thomas/0000-0001-5406-2096 NR 165 TC 19 Z9 23 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 FEB 15 PY 2005 VL 94 IS 3 BP 384 EP 404 DI 10.1016/j.rse.2004.09.011 PG 21 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 895RE UT WOS:000226879900010 ER PT J AU Lauenstein, JM AF Lauenstein, JM TI International workshop on new standard radiation belt and plasma models SO SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS LA English DT Article C1 NASA, Goddard Space Flight Ctr, Muniz Engn Inc, Greenbelt, MD USA. RP Lauenstein, JM (reprint author), NASA, Goddard Space Flight Ctr, Muniz Engn Inc, Greenbelt, MD USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 1542-7390 J9 SPACE WEATHER JI Space Weather PD FEB 12 PY 2005 VL 3 IS 2 AR S02002 DI 10.1029/2004SW000133 PG 2 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 909UA UT WOS:000227885000001 ER PT J AU Schuster, GL Dubovik, O Holben, BN Clothiaux, EE AF Schuster, GL Dubovik, O Holben, BN Clothiaux, EE TI Inferring black carbon content and specific absorption from Aerosol Robotic Network (AERONET) aerosol retrievals SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ATTENUATION CROSS-SECTION; SKY RADIANCE MEASUREMENTS; COMPLEX REFRACTIVE-INDEX; GLOBAL RADIATION BUDGET; OPTICAL-PROPERTIES; LIGHT-ABSORPTION; SULFATE AEROSOLS; UNITED-STATES; ANTHROPOGENIC SULFATE; ATMOSPHERIC AEROSOL AB Black carbon is ubiquitous in the atmosphere and is the main anthropogenic absorbing particulate. Absorption by black carbon is thought to be comparable to the cooling associated with sulfate aerosols, although present-day satellites are incapable of obtaining this measurement, and model estimates are highly uncertain. More measurements of black carbon concentration are necessary for improving and validating transport and general circulation models. The Aerosol Robotics Network (AERONET) of 180 worldwide radiometers offers an opportunity to obtain these measurements. We use the Maxwell Garnett effective medium approximation to infer the column-averaged black carbon concentration and specific absorption of AERONET retrievals at 46 locations. The yearly averaged black carbon column concentrations exhibit the expected regional dependence, with remote island locations having values about an order of magnitude lower than the continental biomass burning locations. The yearly averaged black carbon specific absorption cross section is consistent with other measured values, 9.9 m(2) g(-1) for 19,591 retrievals, but varies from 7.7 to 12.5 m(2) g(-1). We attribute this variability to the details of the size distributions and the fraction of black carbon contained in the aerosol mixture. We also used the Maxwell Garnett equations to parameterize the imaginary refractive index with respect to the black carbon volume fraction, enabling simple but accurate absorption estimates for aerosol mixtures when the black carbon fraction and size distribution is known. The black carbon concentrations that we derive from AERONET measurements correctly describe the radiance field and represent an alternative to absorption optical thickness in the link between models and AERONET measurements. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. NASA, Goddard Space Flight Ctr, Terr Phys Lab, Greenbelt, MD 20771 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. RP NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA. EM gregory.l.schuster@nasa.gov RI Dubovik, Oleg/A-8235-2009 OI Dubovik, Oleg/0000-0003-3482-6460 NR 90 TC 70 Z9 70 U1 2 U2 21 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 FEB 11 PY 2005 VL 110 IS D10 AR D10S17 DI 10.1029/2004JD004548 PG 19 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 898HB UT WOS:000227066300001 ER PT J AU Ebihara, Y Fok, MC Wolf, RA Thomsen, MF Moore, TE AF Ebihara, Y Fok, MC Wolf, RA Thomsen, MF Moore, TE TI Nonlinear impact of plasma sheet density on the storm-time ring current SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY ELECTRIC-FIELD; SOLAR-WIND DENSITY; MAGNETIC-FIELD; IONOSPHERIC CONDUCTIVITY; GEOMAGNETIC STORMS; POLAR IONOSPHERE; LARGE VALUES; MAGNETOSPHERE; MODEL; PARTICLES AB 1] We investigated the nonlinear impact of the plasma sheet density on the total energy of the storm-time ring current by means of a numerical simulation that self-consistently solves the kinetic equation of ring current protons and the closure of the electric current between the magnetosphere and ionosphere. Results of the simulation indicate that when the convection electric field is self-consistently coupled with the ring current, the total energy of the ring current ions trapped by the Earth's magnetic field is roughly proportional to similar toN(ps)(1/2), where N-ps is the plasma sheet density. This nonlinear response results from the strengthened shielding electric field with increasing N-ps. The total energy is almost proportional to N-ps when using an empirical convection electric field, which is independent of the condition of the simulated ring current. An empirical relationship between Nps and the solar wind density was used to estimate time-dependent N-ps. The result shows that the calculated Dst* tends to overshoot the observed one when the non-self-consistent electric field is employed. A better agreement was obtained with the self- consistent electric field. We suggest that the nonlinear response of the ring current to N-ps is one of the mechanisms that impedes the growth of the storm-time ring current. Another mechanism is probably the saturation of the polar cap potential drop for high solar wind electric field. C1 Natl Inst Polar Res, Itabashi Ku, Tokyo 1738515, Japan. NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Rice Univ, Dept Phys & Astron, Houston, TX 77251 USA. RP Natl Inst Polar Res, Itabashi Ku, 1-9-10 Kaga, Tokyo 1738515, Japan. EM ebihara@nipr.ac.jp RI Fok, Mei-Ching/D-1626-2012; Sazykin, Stanislav/C-3775-2008; Ebihara, Yusuke/D-1638-2013; Moore, Thomas/D-4675-2012 OI Sazykin, Stanislav/0000-0002-9401-4248; Ebihara, Yusuke/0000-0002-2293-1557; Moore, Thomas/0000-0002-3150-1137 NR 59 TC 68 Z9 69 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 11 PY 2005 VL 110 IS A2 AR A02208 DI 10.1029/2004JA010435 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 898HJ UT WOS:000227067200002 ER PT J AU Wilson, GR Moore, TE AF Wilson, GR Moore, TE TI Origins and variation of terrestrial energetic neutral atoms outflow SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID HOT OXYGEN GEOCORONA; PRECIPITATION; MAGNETOSPHERE AB [ 1] Analysis of ENA data from the LENA instrument on the IMAGE spacecraft shows that the terrestrial atmosphere is a copious emitter of energetic neutral atoms (<300 eV) under all conditions. When activity is low, the observed emissions are concentrated close to the Earth and are presumed to be the high-energy tail of the warm oxygen geocorona, with energies <2 eV. When activity increases, the relative abundance of the higher-energy neutrals increases, and the emissions can be seen farther from the Earth. Because of the close correlation between the postperigee ENA flux (fluxes seen 1 - 2 hours after spacecraft perigee) and Ap and the fact that the postperigee fluxes are seen when no magnetic storm is in progress we conclude that many of the emitted ENA come from the auroral zone and are produced by energized ionospheric ions rather than by precipitating energetic ions. In more spectacular events, such as the Bastille Day storm event (14 - 16 July 2000), oxygen neutral emissions produced by precipitation of keV ring current oxygen ions can also make an important contribution to the total neutral emission. We conclude that diurnal variation in ENA emissions is a winter hemisphere feature that is absent in the summer hemisphere. As activity increases, the altitude range of the auroral oval ENA emission region increases. C1 ATK Mission Res, Nashua, NH 03062 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Wilson, GR (reprint author), ATK Mission Res, 589 W Hollis St,Suite 201, Nashua, NH 03062 USA. EM gwilson@mrcnh.com RI Moore, Thomas/D-4675-2012 OI Moore, Thomas/0000-0002-3150-1137 NR 15 TC 5 Z9 5 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 FEB 11 PY 2005 VL 110 IS A2 AR A02207 DI 10.1029/2003JA010356 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 898HJ UT WOS:000227067200001 ER PT J AU Howell, LW AF Howell, LW TI Maximum likelihood estimation of spectra information from multiple independent cosmic ray data sets SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE detectors; cosmic rays; broken power law; Cramer-Rao bound; maximum likelihood AB A procedure based on the method of maximum likelihood (ML) is developed to allow an arbitrary number of cosmic ray data sets produced by different instruments with different energy ranges and resolutions to be used together in the analysis of the spectra. Application of this approach will facilitate the interpretation of energy spectra data from multiple science missions and thereby provide more accurate spectral parameter estimates based on the combination of data sets. The benefits of this technique are measured in terms of the reduction of the statistical errors (standard deviations) and biases of the spectra information using the multiple data sets in concert as compared to the statistical errors of the spectra information when the data sets are considered separately. The Cramer-Rao bound (CRB) is derived for multiple independent data sets and provides the fundamental limit to the precision of spectral parameter determination from the combination of cosmic ray data sets. The CRB is used to quantify the efficiency of the derived procedure and also provides a stopping rule in the search for the best unbiased methodology for quantifying the parameters from the data sets. Application of the ML procedure is demonstrated on two simulated data sets acting singly and then together in the estimation of the three broken power law spectral parameters, along with the numerical details required for its successful implementation in practice. Examples of several detector systematic errors and their impact on the efforts to measure the spectra are also investigated. (C) 2004 Elsevier B.V. All rights reserved. C1 NASA, George C Marshall Space Flight Ctr, Sci Directorate, Huntsville, AL 35812 USA. RP Howell, LW (reprint author), NASA, George C Marshall Space Flight Ctr, Sci Directorate, POB 107,XD12, Huntsville, AL 35812 USA. EM leonard.w.howell@nasa.gov NR 11 TC 0 Z9 0 U1 0 U2 0 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 FEB 11 PY 2005 VL 538 IS 1-3 BP 538 EP 549 DI 10.1016/j.nima.2004.08.134 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 898MJ UT WOS:000227080600040 ER PT J AU Talukder, A Morookian, JM Monacos, S Lam, R LeBaw, C Lambert, JL AF Talukder, A Morookian, JM Monacos, S Lam, R LeBaw, C Lambert, JL TI Eye-tracking architecture for biometrics and remote monitoring SO APPLIED OPTICS LA English DT Article AB Eye tracking is one of the latest technologies that has shown potential in several areas, including biometrics; human-computer interactions for people with and without disabilities; and noninvasive monitoring, detection, and even diagnosis of physiological and neurological problems in individuals. Current noninvasive eye-tracking methods achieve a 30-Hz rate with a low accuracy in gaze estimation, which is insufficient for many applications. We propose a new noninvasive optical eye-tracking system that is capable of operating at speeds as high as 6-12 kHz. A new CCD video camera and hardware architecture are used, and a novel fast algorithm leverages specific features of the input CCD camera to yield a real-time eye-tracking system. A field-programmable gate array is used to control the CCD camera and to execute the operations. Initial results show the excellent performance of our system under severe head-motion and low-contrast conditions. (C) 2005 Optical Society of America. C1 CALTECH, Jet Prop Lab, In Situ Instruments Syst Sect, Intelligent Instruments & Syst Technol Grp, Pasadena, CA 91109 USA. RP CALTECH, Jet Prop Lab, In Situ Instruments Syst Sect, Intelligent Instruments & Syst Technol Grp, 4800 Oak Grove Dr,MS 300-128, Pasadena, CA 91109 USA. EM Ashit.Talukder@jpl.nasa.gov NR 18 TC 5 Z9 5 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 FEB 10 PY 2005 VL 44 IS 5 BP 693 EP 700 DI 10.1364/AO.44.000693 PG 8 WC Optics SC Optics GA 899OP UT WOS:000227154400008 PM 15751851 ER PT J AU Gull, TR Vieira, G Bruhweiler, F Nielsen, KE Verner, E Danks, A AF Gull, TR Vieira, G Bruhweiler, F Nielsen, KE Verner, E Danks, A TI The absorption spectrum of high-density stellar ejecta in the line of sight to eta Carinae SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; stars : individual (eta Carinae); stars : winds, outflows ID HOMUNCULUS-NEBULA; EMISSION-LINES; FE II; ULTRAVIOLET AB Using the high-dispersion near-UV (NUV) mode of the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST) to observe eta Carinae, we have resolved and identified over 500 sharp circumstellar absorption lines of iron-group singly ionized and neutral elements with approximate to 20 velocity components ranging from - 146 to - 585 km s(-1). These lines are from transitions originating from ground and metastable levels as high as 40,000 cm(-1) above ground. The absorbing material is located either in dense inhomogeneities in the stellar wind, in the warm circumstellar gas immediately in the vicinity of eta Car, or within the cooler foreground lobe of the Homunculus nebula. We have used classical curve-of-growth analysis to derive atomic level populations for Fe II at - 146 km s(-1) and for Ti II at - 513 km s(-1). These populations, plus photoionization and statistical equilibrium modeling, provide electron temperatures, T-e, densities, n(H), and constraints on distances from the stellar source, d. For the - 146 km s(-1) component, we derive T-e = 6400 K, n(H) greater than or equal to 10(7) - 10(8) cm(-3), and d approximate to 1300 AU. For the - 513 km s(-1) component, we find a much cooler temperature, T-e = 760 K, with n(H) greater than or equal to 10(7) cm(-3); we estimate d approximate to 10; 000 AU. The large distances for these two components place the absorptions in the vicinity of identifiable ejecta from historical events, not near or in the dense wind of eta Car. Further analysis, in parallel with obtaining improved experimental and theoretical atomic data, is underway to determine what physical mechanisms and elemental abundances could explain the large number of strong circumstellar absorption features in the spectrum of eta Car. C1 NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Catholic Univ Amer, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. SGT Inc, Greenbelt, MD 20770 USA. RP Gull, TR (reprint author), NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Code 681, Greenbelt, MD 20771 USA. EM Theodore.R.Gull@nasa.gov; GVieira@stis.gsfc.nasa.gov; FredB@iacs.gsfc.nasa.gov; Nielsen@stis.gsfc.nasa.gov; KVerner@stis.gsfc.nasa.gov; Danks@ngc.com RI Gull, Theodore/D-2753-2012 OI Gull, Theodore/0000-0002-6851-5380 NR 23 TC 29 Z9 29 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 10 PY 2005 VL 620 IS 1 BP 442 EP 449 DI 10.1086/426885 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 895HI UT WOS:000226851300041 ER PT J AU Grady, CA Woodgate, B Heap, SR Bowers, C Nuth, JA Herczeg, GJ Hill, HGM AF Grady, CA Woodgate, B Heap, SR Bowers, C Nuth, JA Herczeg, GJ Hill, HGM TI Resolving the inner cavity of the HD 100546 disk: A candidate young planetary system? SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; planetary systems : protoplanetary disks; stars : individual (HD 100546); stars : pre-main-sequence ID HERBIG-AE/BE STARS; TW-HYDRAE ASSOCIATION; PICTORIS MOVING GROUP; MAIN-SEQUENCE STARS; BETA-PICTORIS; AE STAR; X-RAY; CIRCUMSTELLAR ENVIRONMENT; HD 100546; FUSE OBSERVATIONS AB The inner 100 AU of HD 100546 is studied via far-ultraviolet long-slit spectroscopy with the Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS). The star is surrounded by reflection nebulosity, which can be traced 100 AU in the continuum, and by emission from H I Lyalpha, N I, Si II, and fluorescent H-2 transitions. The Lyalpha emission can be traced up to 200 AU along the system semimajor axis and 300 AU along the semiminor axis. The radial surface brightness profile and the presence of both reflection nebulosity and molecular gas suggest that we have detected the flared surface of the disk predicted from analysis of the IR spectral energy distribution. When corrected for the r(-2) falloff in illumination from the Herbig Be star, the reflection nebulosity, neutral atomic gas, and H-2 emission all reveal the presence of a central cavity extending 0."13 +/- 0."025 (13 AU) from the star, more than 20 times larger in radius than would be expected from dust sublimation alone. The reflection nebulosity within the cavity is centered on a location 0."05 (5 AU) to the southeast of the star along the system semimajor axis. The pericenter asymmetry in the cavity is inconsistent with cavity formation by the combined effects of ice sublimation, radiation pressure blowout on small grains, or other disk chemistry that should produce azimuthally symmetric features. The STIS data are also consistent with a current accretion rate onto the Herbig Be star no higher than a few times 10(-9) M-. yr(-1), an order of magnitude lower than seen in 5 - 8 Myr old Herbig Ae stars. The low accretion rate, large cavity, pericenter asymmetry, and deficit of warm dust grain emission observed over 2 - 8 mum are all consistent with dynamical sculpting of the disk by one or more bodies within the disk. An upper limit to the flux from any chromospherically active, low-mass companion is a factor of 5 - 10 fainter than AU Mic (M1 Ve; t = 12 Myr) at the distance of HD 100546. This upper limit firmly excludes a low-mass stellar companion within the cavity but does not exclude a less active and/or luminous brown dwarf. The absence of similar central clearing in younger Herbig Ae stars suggests that any companion must become externally detectable late in the evolution of the disk, favoring a giant planet as the source of the structure in the HD 100546 disk. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Colorado, Ctr Astrophys & Space Astron, Boulder, CO 80309 USA. Int Space Univ, F-67400 Illkirch Graffenstaden, France. RP Grady, CA (reprint author), NASA, Goddard Space Flight Ctr, Mail Stop 667, Greenbelt, MD 20771 USA. EM cgrady@echelle.gsfc.nasa.gov RI heap, sara/E-2237-2012; Nuth, Joseph/E-7085-2012; OI Herczeg, Gregory/0000-0002-7154-6065 NR 58 TC 49 Z9 49 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 FEB 10 PY 2005 VL 620 IS 1 BP 470 EP 480 DI 10.1086/426887 PN 1 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 895HI UT WOS:000226851300044 ER PT J AU Kuntz, KD Gruendl, RA Chu, YH Chen, CHR Still, M Mukai, K Mushotzky, RF AF Kuntz, KD Gruendl, RA Chu, YH Chen, CHR Still, M Mukai, K Mushotzky, RF TI The optical counterpart of M101 ULX-1 SO ASTROPHYSICAL JOURNAL LA English DT Article DE X-rays : binaries; X-rays : individual (M101 ULX-1) ID X-RAY SOURCE; PHOTOMETRIC SYSTEMS; STARS; PERFORMANCE; CALIBRATION; WASHINGTON; ISOCHRONES; WFPC2; FIELD; X-1 AB We have identified the optical counterpart of the ultraluminous X- ray source M101 ULX- 1 ( CXOKM101 J140332.37 + 542102), by comparing Hubble Space Telescope Advanced Camera for Surveys images with Chandra ACIS- S images. The optical counterpart has and colors consistent with those for a mid- B supergiant. V = 23.75 Archival Wide Field Planetary Camera 2 observations show that the source brightness is constant to within similar to 0.1 mag. The physical association of this source with the ULX is confirmed by Gemini Multi- Object Spectrograph observations that show spatially unresolved He ii lambda4686 and He i lambda5876 emission. These results suggest that M101 ULX- 1 is a high- mass X- ray binary, but deep spectroscopic monitoring observations are needed to determine the detailed properties of this system. C1 Univ Maryland Baltimore Cty, Dept Phys, Baltimore, MD 21250 USA. Univ Illinois, Dept Astron, Urbana, IL 61801 USA. RP Kuntz, KD (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 662, Greenbelt, MD 20771 USA. EM kuntz@milkyway.gsfc.nasa.gov; gruendl@astro.uiuc.edu; chu@astro.uiuc.edu; c-chen@astro.uiuc.edu; still@milkyway.gsfc.nasa.gov; mukai@milkyway.gsfc.nasa.gov; richard@milkyway.gsfc.nasa.gov NR 24 TC 45 Z9 45 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 FEB 10 PY 2005 VL 620 IS 1 BP L31 EP L34 DI 10.1086/428571 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 895HL UT WOS:000226851600008 ER PT J AU Marsh, KA Velusamy, T Dowell, CD Grogan, K Beichman, CA AF Marsh, KA Velusamy, T Dowell, CD Grogan, K Beichman, CA TI Image of Fomalhaut dust ring at 350 microns: The relative column density map shows pericenter-apocenter asymmetry SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; planetary systems; stars : individual (Fomalhaut) ID SPITZER-SPACE-TELESCOPE; DISK; DEBRIS; STARS; VEGA AB We have imaged the circumstellar disk of Fomalhaut at 350 mum wavelength, using SHARC II ( Submillimeter High Angular Resolution Camera II) at the Caltech Submillimeter Observatory. The spatial resolution of the raw images ( 9 ") has been enhanced by a factor of 3 using the HiRes deconvolution procedure. We find that at this wavelength and signal- to- noise ratio (similar to 12), the observed morphology is that of a simple inclined ring (i similar or equal to 70degrees), with little or no other apparent structure - this is the first observation that shows clearly the ring morphology of the disk. We have combined our 350 mum data with Spitzer Space Telescope images at 24, 70, and 160 mum in order to estimate the two- dimensional spatial variation of relative column density (" tau map") using our DISKFIT procedure. The tau map is based on the following physical assumptions: ( 1) the wavelength variation of opacity is the same throughout the disk, ( 2) the radial variation of dust temperature is dictated by the energy balance of individual grains in the stellar radiation field, and ( 3) the vertical scale height of the disk follows a power- law radial variation. The results confirm the ringlike morphology but also show that the geometric center is displaced from the star by about 8 AU and that the ring has an apocentric enhancement of approximately 14% in integrated column density. If we interpret the displacement in terms of elliptical orbital motion due to gravitational perturbation by an unseen planet, then the implied forced eccentricity is similar to 0.06; dynamical modeling then predicts an apocentric density enhancement consistent with that inferred from the tau map. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, IPAC, Pasadena, CA 91125 USA. RP Marsh, KA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM kenneth.a.marsh@jpl.nasa.gov; thangasamy.velusamy@jpl.nasa.gov; cdd@submm.caltech.edu; keith.grogan@jpl.nasa.gov; chas@ipac.caltech.edu NR 15 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 FEB 10 PY 2005 VL 620 IS 1 BP L47 EP L50 DI 10.1086/428401 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 895HL UT WOS:000226851600012 ER PT J AU White, SM Thompson, BJ AF White, SM Thompson, BJ TI High-cadence radio observations of an EIT wave SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona; Sun : flares; Sun : radio radiation ID CORONAL MASS EJECTION; SOLAR-FLARE WAVES; SOHO/EIT OBSERVATIONS; MORETON WAVES; TRANSIENT; MULTIWAVELENGTH; EMISSION; ALPHA; SHOCK AB Sensitive radio observations of the 1997 September 24 EIT wave show its velocity to be 830 km s(-1). The wave first appears a short distance from the flare site, and its trajectory projects back to the flare site at the peak of the impulsive phase. The radio spectrum appears to be consistent with optically thin coronal emission rather than chromospheric emission. The observed radio brightness temperatures are consistent with the EIT fluxes if the temperature of the emitting gas is not at the peak formation temperature of the Fe xii 195 Angstrom line or if abundances are closer to photospheric than coronal. An important result is that no deceleration is observed during the 4 minutes that the wave is visible in the radio images: the discrepancy between EIT wave and Halpha Moreton wave speeds requires that EIT waves slow substantially as they propagate, if they are the same disturbance. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP White, SM (reprint author), Univ Maryland, Dept Astron, College Pk, MD 20742 USA. EM white@astro.umd.edu; barbara.thompson@gsfc.nasa.gov RI Thompson, Barbara/C-9429-2012 NR 24 TC 31 Z9 32 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 10 PY 2005 VL 620 IS 1 BP L63 EP L66 DI 10.1086/428428 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 895HL UT WOS:000226851600016 ER PT J AU Agui, JH Briassulis, G Andreopoulos, Y AF Agui, JH Briassulis, G Andreopoulos, Y TI Studies of interactions of a propagating shock wave with decaying grid turbulence: velocity and vorticity fields SO JOURNAL OF FLUID MECHANICS LA English DT Article ID RAPID DISTORTION THEORY; DIRECT NUMERICAL-SIMULATION; BOUNDARY-LAYER INTERACTION; HOT-WIRE ANEMOMETRY; GENERATED TURBULENCE; ISOTROPIC TURBULENCE; FLOWS; AMPLIFICATION; COMPRESSION; STRAIN AB The unsteady interaction of a moving shock wave with nearly homogeneous and isotropic decaying compressible turbulence has been studied experimentally in a large-scale shock tube facility. Rectangular grids of various mesh sizes were used to generate turbulence with Reynolds numbers based on Taylor's microscale ranging from 260 to 1300. The interaction has been investigated by measuring the three-dimensional velocity and vorticity vectors, the full velocity gradient and rate-of-strain tensors with instrumentation of high temporal and spatial resolution. This allowed estimates of dilatation, compressible dissipation and dilatational stretching to be obtained. The time-dependent signals of enstrophy, vortex stretching/tilting vector and dilatational stretching vector were found to exhibit a rather strong intermittent behaviour which is characterized by high-amplitude bursts with values up to 8 times their r.m.s. within periods of less violent and longer lived events. Several of these bursts are evident in all the signals, suggesting the existence of a dynamical flow phenomenon as a common cause. Fluctuations of all velocity gradients in the longitudinal direction are amplified significantly downstream of the interaction. Fluctuations of the velocity gradients in the lateral directions show no change or a minor reduction through the interaction. Root mean square values of the lateral vorticity components indicate a 25% amplification on average, which appears to be very weakly dependent on the shock strength. The transmission of the longitudinal vorticity fluctuations through the shock appears to be less affected by the interaction than the fluctuations of the lateral components. Non-dissipative vortex tubes and irrotational dissipative motions are more intense in the region downstream of the shock. There is also a significant increase in the number of events with intense rotational and dissipative motions. Integral length scales and Taylor's microscales were reduced after the interaction with the shock in all investigated flow cases. The integral length scales in the lateral direction increase at low Mach numbers and decrease during strong interactions. It appears that in the weakest of the present interactions, turbulent eddies are compressed drastically in the longitudinal direction while their extent in the normal direction remains relatively the same. As the shock strength increases the lateral integral length scales increase while the longitudinal ones decrease. At the strongest interaction of the present flow cases turbulent eddies are compressed in both directions. However, even at the highest Mach number the issue is more complicated since amplification of the lateral scales has been observed in flows with fine grids. Thus the outcome of the interaction strongly depends on the initial conditions. C1 CUNY City Coll, Dept Mech Engn, Expt Aerodynam & Fluid Mech Lab, New York, NY 10031 USA. RP Agui, JH (reprint author), NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RI Andreopoulos, Yiannis/A-1761-2010 NR 56 TC 31 Z9 32 U1 4 U2 15 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD FEB 10 PY 2005 VL 524 BP 143 EP 195 DI 10.1017/S0022112004002514 PG 53 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 908KV UT WOS:000227786800008 ER PT J AU Ichoku, C Remer, LA Eck, TF AF Ichoku, C Remer, LA Eck, TF TI Quantitative evaluation and intercomparison of morning and afternoon Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol measurements from Terra and Aqua SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID OPTICAL DEPTH; AERONET; RETRIEVALS; LAND; VARIABILITY; NETWORK; SYSTEM; OCEANS; SMOKE AB [ 1] The quality of the aerosol optical thickness ( AOT) data retrieved operationally from the Moderate Resolution Imaging Spectroradiometer ( MODIS) sensors aboard the Terra and Aqua satellites, over land, and over ocean from 2000 to 2003 ( Aqua only from June 2002) were evaluated thoroughly. Terra- MODIS versions 3 and 4 data ( T003 and T004) and Aqua- MODIS version 3 data ( A003) were independently and comparatively evaluated with collocated AOT from ground-based Aerosol Robotic Network (AERONET) Sun photometers. At 550 nm wavelength, 67.3%, 55.0%, and 55.5% of AOT from T003, T004, and A003, respectively, meet the prespecified accuracy conditions of +/-( 0.05 + 0.2aot) over land, while about 63.3%, 59.4%, and 62.2% fall within the more stringent range of +/-( 0.03 + 0.05aot) over ocean. However, when based on equal standards of comparison and regression analysis, aerosol retrievals are much more accurate over ocean than over land. Analysis of MODIS full regional AOT averages from 12 land and 6 oceanic regions shows that aerosol loading exhibits an annual cycle in almost every region, with the exception of very remote oceanic regions such as the central Pacific. On the basis of regional monthly averages, west Africa, China, and India show the highest peak monthly mean AOT value of similar to0.7 at 550 nm, while the highest over-ocean aerosol loading occurs over the Mediterranean and Mid-Atlantic oceans, with a regional monthly peak of similar to0.35, which is half of the peak over land. The magnitude of day-to-day variation between morning ( Terra) and afternoon ( Aqua) AOT varies from region to region and increases with aerosol loading for any given region. However, none of the regions examined show any consistent regional trend in morning-to-afternoon aerosol loading, all showing almost equal likelihood of increase or decrease from morning to afternoon. C1 NASA, Goddard Space Flight Ctr, Lab Atmospheres, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Lab Terr Phys, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Ichoku, C (reprint author), NASA, Goddard Space Flight Ctr, Lab Atmospheres, Code 913,Bldg 33,Room C323, Greenbelt, MD 20771 USA. EM ichoku@climate.gsfc.nasa.gov RI ECK, THOMAS/D-7407-2012; Ichoku, Charles/E-1857-2012 OI Ichoku, Charles/0000-0003-3244-4549 NR 28 TC 61 Z9 61 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 FEB 10 PY 2005 VL 110 IS D10 AR D10S03 DI 10.1029/2004JD004987 PG 29 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 898HA UT WOS:000227066200001 ER PT J AU Gray, L Joughin, I Tulaczyk, S Spikes, VB Bindschadler, R Jezek, K AF Gray, L Joughin, I Tulaczyk, S Spikes, VB Bindschadler, R Jezek, K TI Evidence for subglacial water transport in the West Antarctic Ice Sheet through three-dimensional satellite radar interferometry SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID STREAM-C; HYPOTHESIS; VELOCITIES; STAGNATION; ONSET; SHELF; BED AB RADARSAT data from the 1997 Antarctic Mapping Mission are used interferometrically to solve for the 3-dimensional surface ice motion in the interior of the West Antarctic Ice Sheet ( WAIS). An area of similar to125 km(2) in a tributary of the Kamb Ice Stream slumped vertically downwards by up to similar to50 cm between September 26 and October 18, 1997. Areas in the Bindschadler Ice Stream also exhibited comparable upward and downward surface displacements. As the uplift and subsidence features correspond to sites at which the basal water apparently experiences a hydraulic potential well, we suggest transient movement of pockets of subglacial water as the most likely cause for the vertical surface displacements. These results, and related lidar observations, imply that imaging the change in ice surface elevation can help reveal the key role of water in the difficult-to-observe subglacial environment, and its important influence on ice dynamics. C1 Canada Ctr Remote Sensing, Ottawa, ON K1A OY7, Canada. CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Calif Santa Cruz, Dept Earth Sci, Santa Cruz, CA 96064 USA. Earth Sci Agcy, Stateline, NV 89449 USA. NASA, Goddard Space Flight Ctr, Hydrol & Biospher Sci Lab, Greenbelt, MD 20771 USA. Ohio State Univ, Byrd Polar Res Ctr, Columbus, OH 43210 USA. RP Gray, L (reprint author), Canada Ctr Remote Sensing, 588 Booth St, Ottawa, ON K1A OY7, Canada. EM laurence.gray@ccrs.nrcan.gc.ca RI Joughin, Ian/A-2998-2008 OI Joughin, Ian/0000-0001-6229-679X NR 20 TC 113 Z9 115 U1 3 U2 3 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 FEB 8 PY 2005 VL 32 IS 3 AR L03501 DI 10.1029/2004GL021387 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 898GM UT WOS:000227064700002 ER PT J AU Gregg, WW Casey, NW McClain, CR AF Gregg, WW Casey, NW McClain, CR TI Recent trends in global ocean chlorophyll SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BERING-SEA AB A 6-year time series of remotely-sensed global ocean chlorophyll was evaluated using linear regression analysis to assess recent trends. Global ocean chlorophyll has increased 4.1% ( P < 0.05). Most of the increase has occurred in coastal regions, defined as bottom depth < 200 m, where an increase of 10.4% was observed. The main contributors to the increase were the Patagonian Shelf, Bering Sea, and the eastern Pacific, southwest African, and Somalian coasts. Although the global open ocean exhibited no significant change, 4 of the 5 mid-ocean gyres ( Atlantic and Pacific) showed declines in chlorophyll over the 6 years. In all but the North Atlantic gyre, these were associated with significant increases in sea surface temperature in at least one season. These results suggest that changes are occurring in the biology of the global oceans. C1 NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Greenbelt, MD 20771 USA. RP Gregg, WW (reprint author), NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Mail Code 610-1, Greenbelt, MD 20771 USA. EM watson.gregg@nasa.gov NR 7 TC 68 Z9 68 U1 1 U2 30 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 8 PY 2005 VL 32 IS 3 AR L03606 DI 10.1029/2004GL021808 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 898GM UT WOS:000227064700006 ER PT J AU Liang, MC Lane, BF Pappalardo, RT Allen, M Yung, YL AF Liang, MC Lane, BF Pappalardo, RT Allen, M Yung, YL TI Atmosphere of Callisto SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID PHOTOIONIZATION CROSS-SECTIONS; DISSOCIATIVE RECOMBINATION; CARBON-DIOXIDE; SINGLE-PHOTOIONIZATION; IONIC FRAGMENTATION; GALILEAN SATELLITES; OXYGEN ATMOSPHERE; WATER-VAPOR; EV REGION; CO2 AB During the Galileo flybys of Callisto in 1999, a CO(2) atmosphere and an ionosphere were detected. Using the Caltech/Jet Propulsion Laboratory one-dimensional KINETICS model, we have successfully simulated the observed electron density within a factor of 2, while satisfying the observational constraints on carbon and oxygen atoms. We conclude that photoionization of CO(2) alone is insufficient to produce the observed electron density. An atmosphere 20-100 times denser than the CO(2) atmosphere must be introduced, as suggested by Kliore et al. (2002). We show that an O(2)-rich atmosphere is highly probable. However, the atomic oxygen produced from O(2) photodissociation is 2 orders of magnitude greater than the upper limit given by Strobel et al. (2002). The introduction of reactive hydrogen chemistry assuming a surface abundance of H(2)O of similar to2 x 10(9) cm(-3) ( 4 x 10(-8) mbar) is required to reduce the excess atomic O abundance. The calculated atomic O column density is >5 x 10(12) cm(-2), which is about the observed upper limit, suggesting we should be able to detect O in the atmosphere of Callisto. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. MIT, Space Res Ctr, Cambridge, MA 02139 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. RP Liang, MC (reprint author), CALTECH, Jet Prop Lab, MS 183-401,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM mcl@gps.caltech.edu; blane@mit.edu; robert.pappalardo@colorado.edu; maa@gps.caltech.edu; yly@gps.caltech.edu NR 55 TC 18 Z9 18 U1 1 U2 7 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 FEB 8 PY 2005 VL 110 IS E2 AR E02003 DI 10.1029/2004JE002322 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 898HF UT WOS:000227066800001 ER PT J AU Yoonessi, M Toghiani, H Daulton, TL Lin, JS Pittman, CU AF Yoonessi, M Toghiani, H Daulton, TL Lin, JS Pittman, CU TI Clay delamination in clay/poly(dicyclopentadiene) nanocomposites quantified by small angle neutron scattering and high-resolution transmission electron microscopy SO MACROMOLECULES LA English DT Article ID X-RAY-SCATTERING; CARBON-FIBER SURFACES; NYLON 6-CLAY HYBRID; ORIENTATIONAL ORDER; BEHAVIOR; MONTMORILLONITE; DISPERSIONS; KAOLINITE; COLLOIDS; RESIN AB Highly delaminated clay/poly(dicyclopentadiene) nanocomposites were prepared by in-situ, ring-opening metathesis polymerization of presonicated mixtures of the liquid dicyclopentadiene (DCPD) and organically modified Montmorillonite clays. Three nanocomposite series (using Montmorillonites: I-28,I-44pa) of increasing clay loadings (0.5, 1.0, and 2.0 wt%) and modified Montmorillonite PGW (0.5 wt%) were synthesized. The dispersed microstructure of the clays in the nanocomposites was characterized by small-angle neutron scattering (SANS), ultra-small-angle neutron scattering (USANS), small-angle X-ray scattering (SAXS), and high-resolution transmission electron microscopy (HR-TEM). All clays were highly delaminated and well dispersed within their host matrixes. The mean number of individual clay platelets per tactoid was predicted by fitting SANS data to the stacked-disk model and measured directly from HR-TEM images of a large number of tactoids in each sample. SANS results were in good agreement with HR-TEM for composites with low clay concentrations (0.5 wt%); however, deviations were observed at higher clay loadings (2.0 wt%). These deviations are discussed in terms of several factors not taken into account by the stacked-disk model: (a) long-range interactions, which become more important at high loadings; (b) departure of tactoid geometries from parallel stacks of rigid disks; and (c) the polydispersity of tactoid thicknesses. SAXS peaks were not present for most of the synthesized nanocomposites, suggesting a high degree of clay delamination was achieved. However, a broad peak was observed for the 2.0 wt% I-44pa clay nanocomposite, indicating the presence of some larger tactoids than in the other nanocomposites having a range of d-spacings. The HR-TEM measured distributions of clay platelet d-spacings in tactoids dispersed within the nanocomposites which were in the range from 8 to 20 Angstrom (12-15 Angstrom average), indicating that the quaternary ammonium ion pillaring agents were no longer present. These quaternary salts either decomposed during the high-temperature (260 degreesC) stage of curing or were not fully exchanged with the interlayer cations present between all platelet interlayers during the original clay modification. Clay/polyDCPD composites were also prepared using PGW clay modified by poly(ethylene glycol). This clay dispersed more rapidly, needing less sonication than the other clays. The resistance to delamination of all nanocomposites studied increased with greater clay loading under equivalent synthesis conditions. C1 Mississippi State Univ, Dept Chem, Mississippi State, MS 39762 USA. Mississippi State Univ, Dave C Swalm Sch Chem Engn, Mississippi State, MS 39762 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. USN, Res Lab, Marine Geosci Div, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. RP Pittman, CU (reprint author), Mississippi State Univ, Dept Chem, Mississippi State, MS 39762 USA. EM cpittman@ra.msstate.edu NR 62 TC 56 Z9 58 U1 2 U2 26 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD FEB 8 PY 2005 VL 38 IS 3 BP 818 EP 831 DI 10.1021/ma048663e PG 14 WC Polymer Science SC Polymer Science GA 894BJ UT WOS:000226764500025 ER PT J AU Bentrem, FW Pandey, RB AF Bentrem, FW Pandey, RB TI Thermal roughening and deroughening at polymer interfaces in electrophoretic deposition SO MACROMOLECULES LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; GROWTH TEMPERATURE; SURFACE-ROUGHNESS; CHAINS; DYNAMICS; DENSITY; FILMS AB Thermal scaling and relaxation of the interface width in an electrophoretic deposition of polymer chains is examined by a three-dimensional Monte Carlo simulation on a discrete lattice. Variation of the equilibrium interface width W-r with the temperature T shows deroughening W-r similar to T-delta, with delta similar to (1)/(4), at low temperatures and roughening W-r proportional to T-v, with v similar to 0.4, at high temperatures. The roughening-deroughening transition temperature T-t increases with longer chain lengths and is reduced by using the slower segmental dynamics. C1 USN, Res Lab, Div Marine Geosci, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. Univ So Mississippi, Dept Phys & Astron, Hattiesburg, MS 39406 USA. RP Bentrem, FW (reprint author), USN, Res Lab, Div Marine Geosci, Stennis Space Ctr, Stennis Space Ctr, MS 39529 USA. RI Bentrem, Frank/D-5624-2009 OI Bentrem, Frank/0000-0001-5892-4650 NR 23 TC 1 Z9 1 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD FEB 8 PY 2005 VL 38 IS 3 BP 992 EP 995 DI 10.1021/ma034180j PG 4 WC Polymer Science SC Polymer Science GA 894BJ UT WOS:000226764500046 ER PT J AU Rupnowski, P Gentz, M Sutter, JK Kumosa, M AF Rupnowski, P Gentz, M Sutter, JK Kumosa, M TI An evaluation of elastic properties and coefficients of thermal expansion of graphite fibres from macroscopic composite input data SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article DE graphite fibres; properties; indirect methods; elastic constants; coefficients of thermal expansion; Eshelby-Mori-Tanaka ID RAY-DIFFRACTION MEASUREMENTS; IOSIPESCU SHEAR TESTS; +/-45-DEGREES TENSILE; ELEVATED-TEMPERATURES; CARBON-FIBERS; WOVEN; STRESSES; BEHAVIOR; MODULUS; LOADS AB In this work, a methodology has been presented for the evaluation of stiffness properties and temperature-dependent coefficients of thermal expansion of continuous fibres from the macroscopic properties of either unidirectional or woven composites. The methodology was used to determine the stiffness and thermal properties of T650-35 graphite fibres from the macroscopic input data of unidirectional and woven composites based on the same fibres embedded in a PMR-15 polyimide matrix. In the first part of the analysis, the fibre properties were determined directly from the unidirectional composite macro data using the inversed Eshelby-Mori-Tanaka approach. Subsequently, certain fibre properties were additionally evaluated indirectly from the woven composite, using the finite-element method and the concept of a representative unit cell. It has been shown that the temperature-dependent coefficients of thermal expansion of the fibres can be estimated from the unidirectional composite macro data with significantly smaller errors than in the case of the elastic properties. It has also been shown that the errors in the evaluation of the elastic properties of the fibres from the macro unidirectional composite data could be significantly reduced if the fibres were placed in a stiff matrix material: much stiffer than the polyimide resin. The longitudinal and transverse coefficients of thermal expansions and the shear modulus of the T650-35 fibres determined from the unidirectional composite analysis were successfully verified by investigating the woven composite. C1 Univ Denver, Dept Engn, Ctr Adv Mat & Struct, Denver, CO 80208 USA. NASA, Glenn Res Ctr Lewis Field, Cleveland, OH 44135 USA. RP Rupnowski, P (reprint author), Univ Denver, Dept Engn, Ctr Adv Mat & Struct, 2390 S York St, Denver, CO 80208 USA. EM mkumosa@du.edu RI Rupnowski, Przemyslaw/B-3520-2008; OI Rupnowski, Przemyslaw/0000-0003-0040-418X NR 34 TC 4 Z9 4 U1 1 U2 6 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 FEB 8 PY 2005 VL 461 IS 2054 BP 347 EP 369 DI 10.1097/rspa.2004.1358 PG 23 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 895CP UT WOS:000226838800003 ER PT J AU Cronin, CJ Mendel, JE Mukhtar, S Kim, YM Stirbl, RC Bruck, J Sternberg, PW AF Cronin, CJ Mendel, JE Mukhtar, S Kim, YM Stirbl, RC Bruck, J Sternberg, PW TI An automated system for measuring parameters of nematode sinusoidal movement SO BMC GENETICS LA English DT Article ID DEPENDENT PROTEIN-KINASE; ELEGANS BEHAVIORAL PHENOTYPES; CAENORHABDITIS-ELEGANS; C-ELEGANS; NERVOUS-SYSTEM; SYNAPTIC-TRANSMISSION; BODY-SIZE; PLC-BETA; G(Q)ALPHA; GENE AB Background: Nematode sinusoidal movement has been used as a phenotype in many studies of C. elegans development, behavior and physiology. A thorough understanding of the ways in which genes control these aspects of biology depends, in part, on the accuracy of phenotypic analysis. While worms that move poorly are relatively easy to describe, description of hyperactive movement and movement modulation presents more of a challenge. An enhanced capability to analyze all the complexities of nematode movement will thus help our understanding of how genes control behavior. Results: We have developed a user-friendly system to analyze nematode movement in an automated and quantitative manner. In this system nematodes are automatically recognized and a computer-controlled microscope stage ensures that the nematode is kept within the camera field of view while video images from the camera are stored on videotape. In a second step, the images from the videotapes are processed to recognize the worm and to extract its changing position and posture over time. From this information, a variety of movement parameters are calculated. These parameters include the velocity of the worm's centroid, the velocity of the worm along its track, the extent and frequency of body bending, the amplitude and wavelength of the sinusoidal movement, and the propagation of the contraction wave along the body. The length of the worm is also determined and used to normalize the amplitude and wavelength measurements. To demonstrate the utility of this system, we report here a comparison of movement parameters for a small set of mutants affecting the Go/Gq mediated signaling network that controls acetylcholine release at the neuromuscular junction. The system allows comparison of distinct genotypes that affect movement similarly ( activation of Gq-alpha versus loss of Go-alpha function), as well as of different mutant alleles at a single locus ( null and dominant negative alleles of the goa-1 gene, which encodes Goalpha). We also demonstrate the use of this system for analyzing the effects of toxic agents. Concentration-response curves for the toxicants arsenite and aldicarb, both of which affect motility, were determined for wild-type and several mutant strains, identifying P-glycoprotein mutants as not significantly more sensitive to either compound, while cat-4 mutants are more sensitive to arsenite but not aldicarb. Conclusions: Automated analysis of nematode movement facilitates a broad spectrum of experiments. Detailed genetic analysis of multiple alleles and of distinct genes in a regulatory network is now possible. These studies will facilitate quantitative modeling of C. elegans movement, as well as a comparison of gene function. Concentration-response curves will allow rigorous analysis of toxic agents as well as of pharmacological agents. C1 CALTECH, Div Biol, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA USA. CALTECH, HHMI, Pasadena, CA 91125 USA. RP Sternberg, PW (reprint author), CALTECH, HHMI, Pasadena, CA 91125 USA. EM cjc@caltech.edu; mendelj@caltech.edu; saleem@paradise.caltech.edu; youngmee98@yahoo.com; Robert.C.Stirbl@jpl.nasa.gov; bruck@paradise.caltech.edu; pws@caltech.edu RI Cronin, Christopher/H-7406-2014 OI Cronin, Christopher/0000-0002-6229-1259 NR 55 TC 100 Z9 109 U1 0 U2 7 PU BIOMED CENTRAL LTD PI LONDON PA MIDDLESEX HOUSE, 34-42 CLEVELAND ST, LONDON W1T 4LB, ENGLAND SN 1471-2156 J9 BMC GENET JI BMC Genet. PD FEB 7 PY 2005 VL 6 AR 5 DI 10.1186/1471-2156-6-5 PG 19 WC Genetics & Heredity SC Genetics & Heredity GA 900DE UT WOS:000227194800001 PM 15698479 ER PT J AU Woodard, SE AF Woodard, SE TI Methods to increase sound fidelity and quality produced from piezoelectric devices SO JOURNAL OF SOUND AND VIBRATION LA English DT Article AB Methods to increase sound level, fidelity and quality produced from vibrating lamina such as piezoelectric actuators, vibrating plates or vibrating films are presented. Results of using the methods are shown for piezoelectric devices. Four methods are described: (1) tailoring the vibration response to develop desired deformation shapes and amplitudes, (2) mapping vibration out-of-plane deformation to ascertain locations on the surfaces of lamina suitable for stroke-like actuation, (3) coupling vibration to a collection of acoustic chambers and (4) increasing the vibration decay rate. The first two methods provide a single piezoelectric device with the functionality of numerous actuators combined. A piezoelectric actuator with numerous high-amplitude natural vibration responses has been produced using the aforementioned methods. Numerous high-amplitude vibrations increase the functionality of the devices. A collection of acoustic chambers were affixed to the piezoelectric actuator's surface. The addition of the chambers resulted in more efficient audio output. The result of using all of the aforementioned methods is a high fidelity, high-bandwidth, and high sound-quality audio device with a low physical profile. The use of the piezoelectric actuator effectively results in an audio driver with a thickness less than 1 mm. The piezoelectric audio device achieved a response of 93 4 dB measured at 1 cm in the frequency range (1-5 kHz) with very good audio output for frequencies less than 1 kHz. The methods can be used to design other devices using solid-state piezoelectric actuators or vibrating lamina (e.g., plates or films). (C) 2004 Elsevier Ltd. All rights reserved. C1 NASA, Langley Res Ctr, Struct Dynam Branch, Hampton, VA 23681 USA. RP Woodard, SE (reprint author), NASA, Langley Res Ctr, Struct Dynam Branch, MS 230, Hampton, VA 23681 USA. EM s.e.woodard@larc.nasa.gov NR 4 TC 1 Z9 1 U1 0 U2 0 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD FEB 7 PY 2005 VL 280 IS 1-2 BP 127 EP 140 DI 10.1016/j.jsv.2003.12.039 PG 14 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 880VA UT WOS:000225816600007 ER PT J AU Atlas, R Reale, O Shen, BW Lin, SJ Chern, JD Putman, W Lee, T Yeh, KS Bosilovich, M Radakovich, J AF Atlas, R Reale, O Shen, BW Lin, SJ Chern, JD Putman, W Lee, T Yeh, KS Bosilovich, M Radakovich, J TI Hurricane forecasting with the high-resolution NASA finite volume general circulation model SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID TRANSPORT SCHEMES AB A high-resolution finite volume general circulation model (fvGCM), resulting from a development effort of more than ten years, is now being run operationally at the NASA Goddard Space Flight Center and Ames Research Center. The model is based on a finite volume dynamical core with terrain-following Lagrangian control volume discretization and performs efficiently on massive parallel architectures. The computational efficiency allows simulations at a resolution of a quarter of a degree, which is double the resolution currently adopted by most global models in operational weather centers. Such fine global resolution brings us closer to overcoming a fundamental barrier in global atmospheric modeling for both weather and climate, because tropical cyclones can be more realistically represented. In this work, preliminary results are shown. Fifteen simulations of four Atlantic tropical cyclones in 2002 and 2004, chosen because of varied difficulties presented to numerical weather forecasting, are performed. The fvGCM produces very good forecasts of these tropical systems, adequately resolving problems like erratic track, abrupt recurvature, intense extratropical transition, multiple landfall and reintensification, and interaction among vortices. C1 NASA, Goddard Space Flight Ctr, Atmospheres Lab, Greenbelt, MD 20771 USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21201 USA. Sci Applicat Int Corp, Beltsville, MD USA. NOAA, Geophys Fluid Dynam Lab, Princeton, NJ 08542 USA. NASA, Goddard Space Flight Ctr, Earth & Space Data Comp Div, Greenbelt, MD 20771 USA. NASA, Washington, DC 20546 USA. NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. RP Reale, O (reprint author), NASA, Goddard Space Flight Ctr, Atmospheres Lab, Code 910, Greenbelt, MD 20771 USA. EM oreste.reale.l@gsfc.nasa.gov RI Atlas, Robert/A-5963-2011; Bosilovich, Michael/F-8175-2012 OI Atlas, Robert/0000-0002-0706-3560; NR 8 TC 41 Z9 41 U1 0 U2 6 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 FEB 5 PY 2005 VL 32 IS 3 AR L03807 DI 10.1029/2004GL021513 PG 5 WC Geosciences, Multidisciplinary SC Geology GA 895YO UT WOS:000226901200003 ER PT J AU Warneke, T Yang, Z Olsen, S Korner, S Notholt, J Toon, GC Velazco, V Schulz, A Schrems, O AF Warneke, T Yang, Z Olsen, S Korner, S Notholt, J Toon, GC Velazco, V Schulz, A Schrems, O TI Seasonal and latitudinal variations of column averaged volume-mixing ratios of atmospheric CO2 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR ABSORPTION-SPECTROSCOPY AB Column-averaged volume mixing ratios of CO2 have been obtained by ground based high-resolution solar absorption spectrometry at Ny-Alesund (Spitsbergen, 79degreesN) in 2002-2003 and during two ship cruises (54degreesN-34degreesS on the Atlantic in 2003. Precisions are better than 0.4% at Ny-Alesund and better than 0.6% for the cruises. The observed 11 ppmv (part per million by volume) seasonal amplitude of the CO2 column at Ny-Alesund is about 5 ppmv smaller than surface in situ data and 2-4 ppmv greater than model-predictions. The latitudinal gradient of column CO2 inferred from shipborne measurements is less than 2 ppmv in Oct/Nov 2003. During the cruise in Jan/Feb 2003 the observed latitudinal variation is about 7 ppmv. This strong variation is caused by pollution events (biomass burning) and natural variations. Low CO2 columns observed between 5degreesS-15degreesS are attributed to a strong seasonal amplitude of CO2 over Central Africa. C1 Univ Bremen, Inst Environm Phys, D-28359 Bremen, Germany. Max Planck Inst Biogeochem, D-07745 Jena, Germany. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Alfred Wegener Inst Polar & Marine Res, D-27570 Bremerhaven, Germany. Alfred Wegener Inst Polar & Marine Res, D-14473 Potsdam, Germany. RP Warneke, T (reprint author), Univ Bremen, Inst Environm Phys, Otto Hahn Allee 1, D-28359 Bremen, Germany. EM warneke@iup.physik.uni-bremen.de RI Velazco, Voltaire/H-2280-2011; Breon, Francois-Marie/M-4639-2016; Notholt, Justus/P-4520-2016 OI Velazco, Voltaire/0000-0002-1376-438X; Breon, Francois-Marie/0000-0003-2128-739X; Notholt, Justus/0000-0002-3324-885X NR 16 TC 37 Z9 38 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 5 PY 2005 VL 32 IS 3 AR L03808 DI 10.1029/2004GL021597 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 895YO UT WOS:000226901200005 ER PT J AU De Boni, L Silva, DL Neves, UM Feng, K Meador, M Bu, XR Misoguti, L Mendonca, CR AF De Boni, L Silva, DL Neves, UM Feng, K Meador, M Bu, XR Misoguti, L Mendonca, CR TI Two- and three-photon excited fluorescence in Y-shaped molecules SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ABSORPTION CROSS-SECTION; OPTICAL NONLINEARITIES; ORGANIC-COMPOUND; SINGLE-BEAM; DERIVATIVES; INFORMATION; MICROSCOPY; DENDRIMER; STORAGE; DESIGN AB In this work. we have studied the two- and three-photon excited fluorescence on a new series of Y-shaped chromophores, using pulses at 750 and 1400 nm from an optical parametric amplifier pumped by 150 fs pulses from a Ti:sapphire chirped pulse amplified system. The measured two- and three-photon absorption cross-sections are in the order of 1000 x 10(-50) cm(4) s and 5 x 10(-78) cm(6) s(2), respectively. Besides, the two-photon excited fluorescence signal, achieved using low energy pulses (Ti:sapphire modelocked oscillator), were used in an evolutionary strategy to optimize either the laser pulse or the two-photon excited fluorescence. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Sao Paulo, FCM, Inst Fis Sao Carlos, Dept Fis & Ciencia Mat, BR-13560970 Sao Carlos, SP, Brazil. Clark Atlanta Univ, Dept Chem, Atlanta, GA 30314 USA. Clark Atlanta Univ, NASA, Ctr High Performance Polymers & Composites, Atlanta, GA 30314 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Mendonca, CR (reprint author), Univ Sao Paulo, FCM, Inst Fis Sao Carlos, Dept Fis & Ciencia Mat, Av Trobalhador Saocarlense 400,Caia Postal 369, BR-13560970 Sao Carlos, SP, Brazil. EM crmendon@if.sc.usp.br RI De Boni, Leonardo/B-9066-2012; Misoguti, Lino/C-2462-2012; Group, Photonics/D-3910-2012; Mendonca, Cleber/B-9050-2012; Silva, Daniel/L-9680-2014; Sao Carlos Institute of Physics, IFSC/USP/M-2664-2016 OI De Boni, Leonardo/0000-0002-1875-1852; Misoguti, Lino/0000-0001-6624-8453; NR 33 TC 9 Z9 9 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD FEB 4 PY 2005 VL 402 IS 4-6 BP 474 EP 478 DI 10.1016/j.cplett.2004.12.056 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 893KY UT WOS:000226719100034 ER PT J AU Mischna, MA Richardson, MI AF Mischna, MA Richardson, MI TI A reanalysis of water abundances in the Martian atmosphere at high obliquity SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GENERAL-CIRCULATION MODEL; POLAR LAYERED DEPOSITS; CHAOTIC OBLIQUITY; GROUND ICE; MARS; SUBLIMATION; SIMULATION; STABILITY; TERRAIN; CLIMATE AB [1] We take a new look at expected atmospheric water vapor abundances on Mars during periods of high obliquity using the Geophysical Fluid Dynamics Laboratory Mars General Circulation Model. For the first time, the sublimation and burial of the present-day residual polar caps beneath a sublimation lag is considered as the planet shifts from lower to high (45degrees) obliquity periods. Following the elimination of the polar deposits, the only sources for atmospheric water at high obliquity are the low latitude ice deposits emplaced prior to elimination of the polar source. Annual average water vapor abundances are predicted to be only similar to20-80 prmum during extended periods of high obliquity, one to two orders of magnitude less than previous estimates. This has implications for the climate history of the planet as it suggests that during extended periods of high obliquity, there is not a significant greenhouse warming effect from elevated atmospheric water vapor. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Div Geol & Planetary Sci, Pasadena, CA 91125 USA. RP Mischna, MA (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM michael.a.mischna@jpl.nasa.gov NR 21 TC 20 Z9 20 U1 1 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 FEB 4 PY 2005 VL 32 IS 3 AR L03201 DI 10.1029/2004GL021865 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 895YN UT WOS:000226901100005 ER PT J AU Buker, ML Hitchman, MH Tripoli, GJ Pierce, RB Browell, EV Avery, MA AF Buker, ML Hitchman, MH Tripoli, GJ Pierce, RB Browell, EV Avery, MA TI Resolution dependence of cross-tropopause ozone transport over east Asia SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID STRATOSPHERE-TROPOSPHERE EXCHANGE; ATMOSPHERIC PROCESSES; TRACE CONSTITUENTS; VORTICITY; MODELS; MASS; SIMULATION; TURBULENCE; WAVES; DYNAMICS AB [1] Detailed analysis of mesoscale transport of ozone across the tropopause over east Asia during the spring of 2001 is conducted using regional simulations with the University of Wisconsin Nonhydrostatic Modeling System (UWNMS), in situ flight data, and a new two- scale approach to diagnosing this ozone flux. From late February to early April, synoptic activity regularly deformed the tropopause, leading to observations of ozone-rich (concentration exceeding 80 ppbv) stratospheric intrusions and filaments at tropospheric altitudes. Since model resolution is generally not sufficient to capture detailed small-scale mixing processes, an upper bound on the flux is proposed by assuming that there exists a dynamical division by spatial scale, above which the wind conservatively advects large-scale structures, while below it the wind leads to irreversible transport through nonconservative random strain. A formulation for this diagnosis is given and applied to ozone flux across the dynamical tropopause. Simulations were chosen to correspond with DC- 8 flight 15 on 26-27 March over east Asia during the Transport and Chemical Evolution Over the Pacific ( TRACE-P) campaign. Local and domain-averaged flux values using this method agree with other numerical and observational studies in similar synoptic environments. Sensitivity to numerical resolution, prescribed divisional spatial scale, and potential vorticity (PV) level is investigated. Divergent residual flow in regions of high ozone, and PV gradients tended to maximize flux magnitudes. We estimated the domain-integrated flow of ozone out of the lowermost stratosphere to be about 0.127 Tg/day. Spectral analysis of the wind field lends support for utilization of this dynamical division in this methodology. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Wisconsin, Dept Atmospher Sci, Madison, WI USA. RP Buker, ML (reprint author), Univ Wisconsin, Dept Atmospher & Ocean Sci, 1225 W Dayton, Madison, WI 53706 USA. EM marcus@aos.wisc.edu; matt@aos.wisc.edu; tripoli@aos.wisc.edu; r.b.pierce@larc.nasa.gov; e.v.browell@larc.nasa.gov; m.a.avery@larc.nasa.gov RI Pierce, Robert Bradley/F-5609-2010 OI Pierce, Robert Bradley/0000-0002-2767-1643 NR 42 TC 8 Z9 8 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 FEB 4 PY 2005 VL 110 IS D3 AR D03107 DI 10.1029/2004JD004739 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 895YS UT WOS:000226901600001 ER PT J AU Wendisch, M Pilewskie, P Pommier, J Howard, S Yang, P Heymsfield, AJ Schmitt, CG Baumgardner, D Mayer, B AF Wendisch, M Pilewskie, P Pommier, J Howard, S Yang, P Heymsfield, AJ Schmitt, CG Baumgardner, D Mayer, B TI Impact of cirrus crystal shape on solar spectral irradiance: A case study for subtropical cirrus SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID ICE CRYSTALS; MULTIPLE-SCATTERING; RADIATIVE-TRANSFER; CLOUDS; SENSITIVITY; ABSORPTION; REFLECTANCE; TROPOSPHERE; ALBEDO AB [1] Profiles of in situ measurements of ice crystal size distribution of subtropical cirrus were used to calculate solar spectral irradiances above and below the clouds. Spheres and nonspherical ice crystal habits ( columns, hollows, plates, bullets, and aggregates) were assumed in the calculations. The simulation results were compared to irradiance measurements from the NASA Solar Spectral Flux Radiometer. The microphysical and radiation data were collected by three aircraft during CRYSTAL- FACE. Two cirrus cases ( optical thickness of about 1 and 7) from two mission dates ( 26 and 23 July 2002) were investigated in detail. The measured downwelling and upwelling irradiance spectra above the cirrus could mostly be reproduced by the radiation model to within +/-5 - 10% for most ice crystal habits. Below the cirrus the simulations disagreed with the measured irradiances due to surface albedo variability along the flight track, and nonoptimal colocation between the microphysical and irradiance measurements. The impact of shape characteristics of the crystals was important for the reflected irradiances above the optically thin cirrus, especially for small solar zenith angles, because in this case single- scattering dominated the solar radiation field. For the cirrus of moderate optical thickness the enhanced multiple scattering tended to diminish particular shape features caused by nonspherical single- scattering. Within the ice absorption bands the shape- related differences in the absorption characteristics of the individual nonspherical ice crystals were amplified if multiple scattering prevailed. Furthermore, it was found that below the cloud the shape sensitivity of the downwelling irradiance spectra is larger compared to the nonsphericity effects on reflected irradiances above the cirrus. Finally, it was shown that the calculated cirrus solar radiative forcing could vary by as much as 26% depending on the ice crystal habit. C1 Leibniz Inst Tropospher Res, IfT, Leipzig, Germany. NASA, Ames Res Ctr, Div Earth Sci, Moffett Field, CA 94035 USA. BAER Inst, Sonoma, CA 95476 USA. Texas A&M Univ, Dept Atmospher Sci, College Stn, TX 77843 USA. Natl Ctr Atmospher Res, Mesoscale & Microscale Meteorol Div, Boulder, CO 80301 USA. Univ Nacl Autonoma Mexico, Ctr Atmospher Res, Mexico City 04510, DF, Mexico. German Aerosp Ctr, DLR, Inst Phys Atmospher, Oberpfaffenhofen, Germany. RP Wendisch, M (reprint author), Leibniz Inst Tropospher Res, IfT, Leipzig, Germany. EM wendisch@tropos.de; peter.pilewskie@lasp.colorado.edu; jpommier@mail.arc.nasa.gov; howard@solat.arc.nasa.gov; pyang@ariel.met.tamu.edu; heyms1@ucar.edu; schmittc@ucar.edu; darrel@servidor.unam.mx; bernhard.mayer@dlr.de RI Yang, Ping/B-4590-2011; Mayer, Bernhard/B-3397-2011; Heymsfield, Andrew/E-7340-2011; Schmitt, Carl/P-5490-2015; Wendisch, Manfred/E-4175-2013 OI Mayer, Bernhard/0000-0002-3358-0190; Wendisch, Manfred/0000-0002-4652-5561 NR 30 TC 35 Z9 35 U1 4 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 FEB 4 PY 2005 VL 110 IS D3 AR D03202 DI 10.1029/2004JD005294 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 895YS UT WOS:000226901600005 ER PT J AU Kedar, S Webb, FH AF Kedar, S Webb, FH TI The ocean's seismic hum SO SCIENCE LA English DT Editorial Material ID MICROSEISMS C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Kedar, S (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM sharon.kedar@jpl.nasa.gov; frank.webb@jpl.nasa.gov NR 12 TC 25 Z9 26 U1 1 U2 4 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD FEB 4 PY 2005 VL 307 IS 5710 BP 682 EP 683 DI 10.1126/science.1108380 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 894TQ UT WOS:000226814900027 PM 15692037 ER PT J AU Orton, GS Yanamandra-Fisher, PA AF Orton, GS Yanamandra-Fisher, PA TI Saturn's temperature field from high-resolution middle-infrared imaging SO SCIENCE LA English DT Article ID JUPITER UPPER TROPOSPHERE; SPATIAL-ORGANIZATION; THERMAL STRUCTURE; TIME-DEPENDENCE; CLOUD LEVEL; ZONAL WINDS; ENCOUNTER; DYNAMICS; PLANETS; SYSTEM AB Saturn was imaged between 8 and 24.5 micrometers at similar to3000-kilometer resolution with the Keck I Telescope. Saturn's atmosphere has zonal temperature bands, which are mostly uncorrelated with visible cloud reflectivity, strong 100-millibar zonal temperature oscillations near 32degreesS, a warm south polar cap, and a compact hot point within 3degrees of the south pole. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Orton, GS (reprint author), CALTECH, Jet Prop Lab, MS 169-237,4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 22 TC 44 Z9 44 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD FEB 4 PY 2005 VL 307 IS 5710 BP 696 EP 698 DI 10.1126/science.1105730 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 894TQ UT WOS:000226814900034 PM 15692044 ER PT J AU Gopalswamy, N Barbieri, L Lu, G Plunkett, SP Skoug, RM AF Gopalswamy, N Barbieri, L Lu, G Plunkett, SP Skoug, RM TI Introduction to the special section: Violent Sun Earth connection events of October-November 2003 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB [1] During 2003 October and November, a series of solar eruptions occurred from three solar active regions. Some of these eruptions were extreme in terms of their origin ( source properties) and heliospheric consequences. This paper summarizes the first results of the analysis of these violent Sun-Earth connection events. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NCAR, High Altitude Observ, Boulder, CO USA. USN, Res Lab, Washington, DC 20375 USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM gopals@fugee.gsfc.nasa.gov; lbarbieri@mail.hst.nasa.gov; ganglu@ucar.edu; simon.plunkett@nrl.navy.mil; rskoug@lanl.gov RI Gopalswamy, Nat/D-3659-2012; Lu, Gang/A-6669-2011 NR 13 TC 27 Z9 27 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 FEB 3 PY 2005 VL 32 IS 3 AR L03S01 DI 10.1029/2005GL022348 PG 3 WC Geosciences, Multidisciplinary SC Geology GA 895YM UT WOS:000226901000003 ER PT J AU Owen, CJ Slavin, JA Fazakerley, AN Dunlop, MW Balogh, A AF Owen, CJ Slavin, JA Fazakerley, AN Dunlop, MW Balogh, A TI Cluster electron observations of the separatrix layer during traveling compression regions SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID GEOTAIL OBSERVATIONS; TAIL AB [ 1] We present Cluster 4-point observations of electrons during traveling compression regions ( TCRs) on 19 September 2001. The electron and \B\ signatures vary with distance from the plasma sheet, confirming that transient plasma sheet bulges propagate past Cluster. TCRs with \B\ increases have either no electron signature, or unidirectional similar to1 keV electrons at the plasma sheet edge. However, spacecraft initially near the plasma sheet edge are engulfed within the bulge and observe a diamagnetic reduction in \B\. In cases where the underlying plasma sheet bulge moves earthward, electrons at the plasma sheet edge stream tailward. We suggest this represents either a remote observation of electrons closing the Hall current system in an ion diffusion region located farther tailward, or the outflow jets along the separatrix formed by a second neutral line located farther earthward of the spacecraft. The latter case implies the simultaneous action of multiple X-lines in the near-Earth tail. C1 Mullard Space Sci Lab, Holmbury, England. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Rutherford Appleton Lab, Chilton, England. Univ London Imperial Coll Sci Technol & Med, London, England. RP Owen, CJ (reprint author), Mullard Space Sci Lab, Holmbury, England. EM cjo@mssl.ucl.ac.uk RI Owen, Christopher/C-2999-2008; Slavin, James/H-3170-2012 OI Owen, Christopher/0000-0002-5982-4667; Slavin, James/0000-0002-9206-724X NR 10 TC 16 Z9 16 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 3 PY 2005 VL 32 IS 3 AR L03104 DI 10.1029/2004GL021767 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 895YM UT WOS:000226901000002 ER PT J AU Collier, MR Moore, TE Fok, MC Pilkerton, B Boardsen, S Khan, H AF Collier, MR Moore, TE Fok, MC Pilkerton, B Boardsen, S Khan, H TI Low-energy neutral atom signatures of magnetopause motion in response to southward B-z SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; SOLAR-WIND CONDITIONS; MHD SIMULATION; 1 AU; SHAPE; MAGNETOSHEATH; LOCATION; PROPAGATION; EMISSION; LATITUDE AB We report an event observed by the Low-Energy Neutral Atom (LENA) imager on 18 April 2001, in which enhanced neutral atom emission was observed coming from the direction of the Sun and from the general direction of the subsolar magnetopause. The enhanced neutral atom emission is shown to be primarily a result of increased solar wind charge exchange with the Earth's hydrogen exosphere, that is, enhanced neutral solar wind formation, occurring in conjunction with a southward turning of the interplanetary magnetic field (IMF) which moves the magnetopause closer to the Earth. It is shown that the neutral atom flux under compressed magnetopause conditions is extremely sensitive to changes in the IMF north-south component. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Leicester, Leicester, Leics, England. RP Collier, MR (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. EM michael.r.collier@nasa.gov RI Moore, Thomas/D-4675-2012; Fok, Mei-Ching/D-1626-2012; Collier, Michael/I-4864-2013 OI Moore, Thomas/0000-0002-3150-1137; Collier, Michael/0000-0001-9658-6605 NR 36 TC 19 Z9 19 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 3 PY 2005 VL 110 IS A2 AR A02102 DI 10.1029/2004JA010626 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 895ZI UT WOS:000226903300002 ER PT J AU Stubbs, TJ Vondrak, RR Ostgaard, N Sigwarth, JB Frank, LA AF Stubbs, TJ Vondrak, RR Ostgaard, N Sigwarth, JB Frank, LA TI Simultaneous observations of the auroral ovals in both hemispheres under varying conditions SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INTERPLANETARY MAGNETIC-FIELD; DEPENDENCE; IONOSPHERE; SPACECRAFT; CONJUGATE; SYSTEM; FLOWS AB This is the first analysis to use simultaneous observations of the entire auroral ovals in both hemispheres to track their location. Data was used from the Polar VIS and IMAGE FUV imagers on 23 October 2002 and plotted in AACGM coordinates. Results showed the expected IMF B-y-dependent asymmetry along the dawndusk meridian; however, there was an unexpected offset of both ovals toward dawn. Evidence is also shown for an asymmetry along the noon-midnight meridian dependent on both dipole tilt angle and the sense of IMF B-x. During a brief period of weak IMF B-z > 0 and IMF B-x > 0, the southern oval is observed to move equatorward relative to the northern oval, consistent with tail lobe reconnection occurring only in the southern hemisphere. This has important implications for the global response of the magnetosphere to different interplanetary conditions. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Iowa, Dept Phys & Astron, Iowa City, IA 52242 USA. RP Stubbs, TJ (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Mail Code 690-4, Greenbelt, MD 20771 USA. EM tstubbs@lepvax.gsfc.nasa.gov RI Stubbs, Timothy/I-5139-2013 OI Stubbs, Timothy/0000-0002-5524-645X NR 10 TC 12 Z9 12 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 FEB 2 PY 2005 VL 32 IS 3 AR L03103 DI 10.1029/2004GL021199 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 895YL UT WOS:000226900900001 ER PT J AU Echer, E Gonzalez, WD Tsurutani, BT Vieira, LEA Alves, MV Gonzalez, ALC AF Echer, E Gonzalez, WD Tsurutani, BT Vieira, LEA Alves, MV Gonzalez, ALC TI On the preferential occurrence of interplanetary shocks in July and November: Causes (solar wind annual dependence) and consequences (intense magnetic storms) SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID CORONAL MASS EJECTIONS; HELIOSPHERIC CURRENT SHEET; HELIOGRAPHIC LATITUDE-DEPENDENCE; GEOMAGNETIC-ACTIVITY; SEMIANNUAL VARIATION; MINIMUM 1995-1996; CYCLE VARIATIONS; MAXIMUM 2000; SIGNATURES; POLARITY AB An annual dependence of interplanetary shock rate near 1 AU was found with preferential shock occurrence in July and in November. Although a solar origin for this dependence can not be discarded, it is shown that at least part of this shock distribution can be explained or caused by the annual dependence of solar wind parameters. Such annual dependence in plasma and magnetic field parameters makes the shock formation easier, in the second half year, due to the lower average solar wind bulk and characteristic speeds (Alfvenic and magnetosonic). These asymmetric interplanetary space propagation conditions are probably due to the Earth being exposed to solar wind from different solar magnetic hemispheres in both half years. Furthermore, the peaks in shock distribution are coincident with the peaks in the very intense geomagnetic storms distribution found by Clua de Gonzalez et al. [2001]. It is suggested that the irregularity in geomagnetic activity is associated with the shock rate annual dependence. These results might imply that solar wind emitted from the opposite solar magnetic hemispheres has slightly different properties. C1 Inst Nacl Pesquisas Espaciais, Geofis Espacial, BR-12245970 Sao Jose Dos Campos, Brazil. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Echer, E (reprint author), Inst Nacl Pesquisas Espaciais, Geofis Espacial, Avenida Astronauts 1758,POB 515, BR-12245970 Sao Jose Dos Campos, Brazil. EM eecher@dge.inpe.br RI Vieira, Luis Eduardo/A-5548-2008; Alves, Maria Virginia/G-3325-2014 OI Vieira, Luis Eduardo/0000-0002-9376-475X; NR 59 TC 4 Z9 4 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 2 PY 2005 VL 110 IS A2 AR A02101 DI 10.1029/2004JA010527 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 895ZH UT WOS:000226903200001 ER PT J AU Yanev, TK Choudhury, BJ Mishev, DN AF Yanev, TK Choudhury, BJ Mishev, DN TI New index to remove from a spectral mixture an unknown spectral component SO ACTA ASTRONAUTICA LA English DT Article; Proceedings Paper CT 53rd International-Astronautical-Federation Congress CY OCT 10-19, 2002 CL HOUSTON, TX SP Int Astronaut Federat AB More than one spectral classes are usually found within a pixel when measuring the spectral reflectance (the spectral reflectance coefficients (SRC) in particular) of natural formations in the visible (VIS) and near infrared (NIR) spectral ranges. The spectral mixture "soil-vegetation" is a typical example. The decomposition of this mixture is strongly impeded because only the mixture SRC are usually available, the soil SRC and the vegetation coverage coefficient p not being known in advance. This is especially true for remotely sensed data in field experiments. Under the assumption that the soil SRC are a linear function of the wavelength two SRC transforms were defined and studied in previous papers of the authors. The second transform is the theta coefficient, which is free of the unknown linear soil component as well as of the unknown coverage coefficient p. In previous studies of the authors theta was examined in the case when the soil SRC may be approximated by one straight line. In this work, theta was obtained and studied for soil types that may be satisfactory piece-wise approximated by two different crossing straight lines within the VIS and NIR ranges. Thus, the theta coefficient may be employed to eliminate the unknown soil SRC from the measured mixture SRC in the case when the soil SRC are nonlinear wavelength function which may be fitted by two straight lines. Examples of USA and Bulgarian soil types are given in the study, which meet this requirement. (C) 2004 Elsevier Ltd. All rights reserved. C1 Bulgarian Acad Sci, Solar Terr Influences Lab, BU-1113 Sofia, Bulgaria. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Yanev, TK (reprint author), Bulgarian Acad Sci, Solar Terr Influences Lab, Acad G Bonchev Str Bl 3, BU-1113 Sofia, Bulgaria. NR 12 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 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD FEB PY 2005 VL 56 IS 4 BP 471 EP 475 DI 10.1016/j.actaastro.2004.05.071 PG 5 WC Engineering, Aerospace SC Engineering GA 888PZ UT WOS:000226388000005 ER PT J AU Gilmore, MS Collins, GC Crumpler, LS Cutts, JA deCharon, AV Head, JW Nock, KT Parry, M Yingst, RA AF Gilmore, MS Collins, GC Crumpler, LS Cutts, JA deCharon, AV Head, JW Nock, KT Parry, M Yingst, RA TI Investigation of the application of aerobot technology at Venus SO ACTA ASTRONAUTICA LA English DT Article ID MAGELLAN DATA; GLOBAL DISTRIBUTION; SURFACE; GEOCHEMISTRY; VOLCANISM; FEATURES; GEOLOGY; DOMES; EMISSION; ORIGIN AB Robotic aerovehicles, or aerobots, can perform long duration detailed studies of planetary surfaces and atmospheres in three dimensions. Here we explore specific abilities of an aerobot mission to Venus using two concept missions: the Balloon Experiment at Venus (BEV) and the Venus Flyer Robot (VFR). Oscillating between 40 and 60km altitude, the BEV is designed to collect atmospheric data over a nominal lifetime of weeks as well as image the surface. The VFR, with its ability to descend to the surface, can collect cm-m scale visible and near-infrared images of the surface, collect compositional and dynamical data of the lower atmosphere, and measure the composition of the Venus surface with a snake-mounted detector. These concept missions are used to calculate sample aerobot trajectories and descent scenarios which utilize variations in wind speed, altitude and surface slopes to maximize data collection. The trajectories are applied to two example geotraverses across Atla Regio and Ovda Regio. Data collected at these or similar targets by an aerobot can address several unresolved questions about Venus such as the nature of the lower atmosphere and atmosphere-surface interactions and the presence or absence of continental crust. (C) 2004 Elsevier Ltd. All rights reserved. C1 Wesleyan Univ, Dept Earth & Environm Sci, Middletown, CT 06459 USA. Wheaton Coll, Dept Phys & Astron, Norton, MA 02766 USA. New Mexico Museum Nat Hist & Sci, Albuquerque, NM 87104 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Bigelow Lab Ocean Sci, Boothbay Harbor, ME 04575 USA. Brown Univ, Dept Geol Sci, Providence, RI 02912 USA. Global Aerosp Corp, Altadena, CA 91001 USA. Univ London Imperial Coll Sci & Technol, Astrophys Grp, Blackett Lab, London SW7 2AZ, England. Univ Wisconsin, Green Bay, WI 54311 USA. RP Gilmore, MS (reprint author), Wesleyan Univ, Dept Earth & Environm Sci, 265 Church St, Middletown, CT 06459 USA. EM mgilmore@wesleyan.edu RI Gilmore, Martha/G-5856-2011 NR 50 TC 4 Z9 4 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD FEB PY 2005 VL 56 IS 4 BP 477 EP 494 DI 10.1016/j.actaastro.2004.06.005 PG 18 WC Engineering, Aerospace SC Engineering GA 888PZ UT WOS:000226388000006 ER PT J AU Moradkhani, H Sorooshian, S Gupta, HV Houser, PR AF Moradkhani, H Sorooshian, S Gupta, HV Houser, PR TI Dual state-parameter estimation of hydrological models using ensemble Kalman filter SO ADVANCES IN WATER RESOURCES LA English DT Article DE streamflow forecasting; stochastic processes; data assimilation; ensemble Kalman filter; dual estimation; Kernel smoothing ID RAINFALL-RUNOFF MODELS; DATA ASSIMILATION; GLOBAL OPTIMIZATION; UNCERTAINTY; CALIBRATION AB Hydrologic models are twofold: models for understanding physical processes and models for prediction. This study addresses, the latter, which modelers use to predict, for example, streamflow at some future time given knowledge of the current state of the system and model parameters. In this respect, good estimates of the parameters and state variables are needed to enable the model to generate accurate forecasts. In this paper, a dual state-parameter estimation approach is presented based on the Ensemble Kalman Fater (EnKF) for sequential estimation of both parameters and state variables of a hydrologic model. A systematic approach for identification of the perturbation factors used for ensemble generation and for selection of ensemble size is discussed. The dual EnKF methodology introduces a number of novel features: (1) both model states and parameters can he estimated simultaneously: (2) the algorithm is recursive and therefore does not require storage of all past information. as is the case in the batch calibration procedures; and (3) the various sources of uncertainties can be properly addressed. including input, output, and parameter uncertainties. The applicability and usefulness of the dual EnKF approach for ensemble streamflow forecasting is demonstrated using conceptual rainfall-runoff model. (C) 2004 Elsevier Ltd. All rights reserved. C1 Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA. Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. NASA, Goddard Space Flight Ctr, Hydrol Sci Branch, Greenbelt, MD 20771 USA. RP Moradkhani, H (reprint author), Univ Calif Irvine, Dept Civil & Environm Engn, Irvine, CA 92697 USA. EM moradkha@uci.edu RI Gupta, Hoshin/D-1642-2010; sorooshian, soroosh/B-3753-2008; Houser, Paul/J-9515-2013; Moradkhani, Hamid/B-1571-2012 OI Gupta, Hoshin/0000-0001-9855-2839; sorooshian, soroosh/0000-0001-7774-5113; Houser, Paul/0000-0002-2991-0441; NR 48 TC 345 Z9 369 U1 12 U2 72 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD FEB PY 2005 VL 28 IS 2 BP 135 EP 147 DI 10.1016/j.advwatres.2004.09.002 PG 13 WC Water Resources SC Water Resources GA 892BW UT WOS:000226625700003 ER PT J AU Gao, C Yang, SC Luo, SJ Liu, F Schuster, DM AF Gao, C Yang, SC Luo, SJ Liu, F Schuster, DM TI Calculation of airfoil flutter by an Euler method with approximate boundary conditions SO AIAA JOURNAL LA English DT Article ID LIMIT-CYCLE OSCILLATIONS; NAVIER-STOKES EQUATIONS; WING FLUTTER; AEROELASTIC ANALYSIS; COMPUTATIONS; PREDICTION AB A numerical method is demonstrated for solving the steady and unsteady Euler equations on stationary Cartersian grids for the purpose of time-domain simulation of aeroelastic problems. Wall boundary conditions are implemented on nonmoving mean chord positions by assuming the airfoil being thin and undergoing small deformation, whereas the full nonlinear Euler equations are used in the flowfield for accurate resolution of shock waves and vorticity. The method does not require the generation of moving body-fitted grids; and thus can be easily deployed in any fluid-structure interaction problem involving relatively small deformation of a thin body. The first-order wall boundary conditions are used in solving the full Enter equations, and the results are compared with the Euler solutions using the exact boundary conditions and known experimental dam It is shown that the first-order boundary conditions are adequate to represent airfoils of typical thicknesses with small deformation for both steady and unsteady calculations. Flutter boundaries are accurately predicted by this method for the Isogai wing model test case. C1 Univ Calif Irvine, Dept Mech & Aerosp Engn, Irvine, CA 92697 USA. NASA, Langley Res Ctr, Aeroelastic Branch, Hampton, VA 23681 USA. RP Gao, C (reprint author), Northwestern Polytech Univ, Ctr Aerodyanm Res & Dev, Xian 710072, Peoples R China. NR 29 TC 9 Z9 11 U1 0 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 FEB PY 2005 VL 43 IS 2 BP 295 EP 305 DI 10.2514/1.5752 PG 11 WC Engineering, Aerospace SC Engineering GA 892CD UT WOS:000226626400006 ER PT J AU Yamaleev, NK Carpenter, MH Ferguson, F AF Yamaleev, NK Carpenter, MH Ferguson, F TI Reduced-order model for efficient simulation of synthetic jet actuators SO AIAA JOURNAL LA English DT Article ID AIRFOIL; DELAY AB A new reduced-order model of multidimensional synthetic jet actuators that combines the accuracy and conservation properties of full numerical simulation methods with the efficiency of simplified zero-order models is proposed. The multidimensional actuator is simulated by the solution of the time-dependent compressible quasi-one-dimensional Eider equations, whereas the diaphragm is modeled as a moving boundary. The governing equations are approximated with a fourth-order finite difference scheme on a moving mesh, such that one of the mesh boundaries coincides with the diaphragm. The reduced-order model of the actuator has several advantages. In contrast to the zero-dimensional models, this approach provides conservation of mass, momentum, and energy. Furthermore, the new method is computationally much more efficient than the two-dimensional Navier-Stokes simulation of the actuator cavity flow, while providing practically the same accuracy in the exterior flowfield. The most distinctive feature of the present model is its ability to predict the resonance characteristics of synthetic jet actuators; this is not practical when the three-dimensional models are used because of the computational cost involved. Numerical results demonstrating the accuracy of the new reduced-order model and its limitations are presented. C1 N Carolina Agr & Tech State Univ, Dept Math, Greensboro, NC 27411 USA. NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA. N Carolina Agr & Tech State Univ, Dept Engn Mech, Greensboro, NC 27411 USA. RP Yamaleev, NK (reprint author), N Carolina Agr & Tech State Univ, Dept Math, Greensboro, NC 27411 USA. EM nkyamale@ncat.edu NR 17 TC 8 Z9 8 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091-4344 USA SN 0001-1452 J9 AIAA J JI AIAA J. PD FEB PY 2005 VL 43 IS 2 BP 357 EP 369 DI 10.2514/1.7077 PG 13 WC Engineering, Aerospace SC Engineering GA 892CD UT WOS:000226626400012 ER PT J AU Waters, WW Platts, SH Mitchell, BM Whitson, PA Meck, JV AF Waters, WW Platts, SH Mitchell, BM Whitson, PA Meck, JV TI Plasma volume restoration with salt tablets and water after bed rest prevents orthostatic hypotension and changes in supine hemodynamic and endocrine variables SO AMERICAN JOURNAL OF PHYSIOLOGY-HEART AND CIRCULATORY PHYSIOLOGY LA English DT Article DE simulated microgravity; cardiovascular; hypovolemia; cardiopulmonary-arterial baroreceptor reflex interaction; adrenergic receptors ID SYMPATHETIC-NERVE ACTIVITY; BODY NEGATIVE-PRESSURE; DOWN TILT BEDREST; SIMULATED MICROGRAVITY; VASCULAR-RESISTANCE; BAROREFLEX RESPONSES; ADRENERGIC-RECEPTORS; BETA-ADRENOCEPTORS; BLOOD-PRESSURE; HUMAN-HEART AB Head-down bed rest changes the values of many cardiovascular and endocrine variables and also elicits significant hypovolemia. Because previous studies had not controlled for hypovolemia, it is unknown whether the reported changes were primary effects of bed rest or secondary effects of bed rest-induced hypovolemia. We hypothesized that restoring plasma volume with salt tablets and water after 12 days of head-down bed rest would result in an absence of hemodynamic and endocrine changes and a reduced incidence of orthostatic hypotension. In 10 men, we measured changes from pre-bed-rest to post-bed-rest in venous and arterial pressures; heart rate; stroke volume; cardiac output; vascular resistance; plasma norepinephrine, epinephrine, vasopressin, renin activity (PRA), and aldosterone responses to different tilt levels (0degrees, -10degrees, 20degrees, 30degrees, and 70degrees); and plasma volume and platelet alpha(2)- and lymphocyte beta(2)-adrenoreceptor densities and affinities (0degrees tilt only). Fluid loading at the end of bed rest restored plasma volume and resulted in the absence of post-bed-rest orthostatic hypotension and changes in supine hemodynamic and endocrine variables. Fluid loading did not prevent post-bed-rest increases in beta(2)-adrenoreceptor density or decreases in the aldosterone-to-PRA ratio ( P = 0.05 for each). Heart rate, epinephrine, and PRA responses to upright tilt after bed rest were increased ( P < 0.05), despite the fluid load. These results suggest that incidents of orthostatic hypotension and many of the changes in supine hemodynamic and endocrine variables in volume-depleted bed-rested subjects occur secondarily to the hypovolemia. Despite normovolemia after bed rest, β(2)-adrenoreceptors were upregulated, and heart rate, epinephrine, and PRA responses to tilt were augmented, indicating that these changes are independent of volume depletion. C1 Wyle Labs Inc, Human Adaptat & Countermeasures Off, Houston, TX USA. Univ Space Res Assoc, Div Space Life Sci, Houston, TX USA. NASA, Lyndon B Johnson Space Ctr, Astronaut Off, Houston, TX 77058 USA. NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Off, Houston, TX 77058 USA. RP Waters, WW (reprint author), Wyle Labs Inc, Human Adaptat & Countermeasures Off, Houston, TX USA. NR 55 TC 32 Z9 33 U1 0 U2 0 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0363-6135 J9 AM J PHYSIOL-HEART C JI Am. J. Physiol.-Heart Circul. Physiol. PD FEB PY 2005 VL 288 IS 2 BP H839 EP H847 DI 10.1152/ajpheart.00220.2004 PG 9 WC Cardiac & Cardiovascular Systems; Physiology; Peripheral Vascular Disease SC Cardiovascular System & Cardiology; Physiology GA 888FE UT WOS:000226358800046 PM 15486040 ER PT J AU Juck, DF Whissell, G Steven, B Pollard, W McKay, CP Greer, CW Whyte, LG AF Juck, DF Whissell, G Steven, B Pollard, W McKay, CP Greer, CW Whyte, LG TI Utilization of fluorescent microspheres and a green fluorescent protein-marked strain for assessment of microbiological contamination of permafrost and ground ice core samples from the Canadian High Arctic SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID SIBERIAN PERMAFROST; BACTERIAL-ACTIVITY; POLAR-REGIONS; SEDIMENTS; MICROORGANISMS; SOIL; DNA; DIVERSITY; MARS; LIFE AB Fluorescent microspheres were applied in a novel fashion during subsurface drilling of permafrost and ground ice in the Canadian High Arctic to monitor the exogenous microbiological contamination of core samples obtained during the drilling process. Prior to each drill run, a concentrated fluorescent microsphere (0.5-mum diameter) solution was applied to the interior surfaces of the drill bit, core catcher, and core tube and allowed to dry. Macroscopic examination in the field demonstrated reliable transfer of the microspheres to core samples, while detailed microscopic examination revealed penetration levels of less than 1 cm from the core exterior. To monitor for microbial contamination during downstream processing of the permafrost and ground ice cores, a Pseudomonas strain expressing the green fluorescent protein (GFP) was painted on the core exterior prior to processing. Contamination of the processed core interiors with the GFP-expressing strain was not detected by culturing the samples or by PCR to detect the gfp marker gene. These methodologies were quick, were easy to apply, and should help to monitor the exogenous microbiological contamination of pristine permafrost and ground ice samples for downstream culture-dependent and culture-independent microbial analyses. C1 Natl Res Council Canada, Biotechnol Res Inst, Montreal, PQ H4P 2R2, Canada. McGill Univ, Dept Nat Resource Sci, Montreal, PQ, Canada. McGill Univ, Dept Geog, Montreal, PQ, Canada. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Juck, DF (reprint author), Natl Res Council Canada, Biotechnol Res Inst, 6100 Royalmount Ave, Montreal, PQ H4P 2R2, Canada. EM david.juck@cnrc-nrc.gc.ca RI Steven, Blaire/E-5295-2012 OI Steven, Blaire/0000-0001-5940-2432 NR 31 TC 31 Z9 36 U1 2 U2 10 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD FEB PY 2005 VL 71 IS 2 BP 1035 EP 1041 DI 10.1128/AEM.71.2.1035-1041.2005 PG 7 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 897YS UT WOS:000227043400056 PM 15691963 ER PT J AU Richter, H Barbieri, E Figueroa, F AF Richter, H Barbieri, E Figueroa, F TI Modelling and validation of a propellant mixer for controller design SO APPLIED MATHEMATICAL MODELLING LA English DT Article ID TRACKING AB A mixing chamber used in rocket engine testing at the NASA Stennis Space Center is modelled by a system of two nonlinear ordinary differential equations. The mixer is used to condition the thermodynamic properties of cryogenic liquid propellant by controlled injection of the same substance in the gaseous phase. The three inputs of the mixer are the positions of the valves regulating the liquid and gas flows at the inlets, and the position of the exit valve regulating the flow of conditioned propellant. Mixer operation during a test requires the regulation of its internal pressure, exit mass flow, and exit temperature. A mathematical model is developed to facilitate subsequent controller designs. The model must be simple enough to lend itself to subsequent feedback controller design, yet its accuracy must be tested against real data. For this reason, the model includes function calls to thermodynamic property data. Some structural properties of the resulting model that pertain to controller design, such as uniqueness of the equilibrium point, feedback linearizability and local stability are shown to hold under conditions having direct physical interpretation. The existence of fixed valve positions that attain a desired operating condition is also shown. Validation of the model against real data is likewise provided. (C) 2004 Published by Elsevier Inc. C1 NASA, Stennis Space Ctr, NRC Res Associate, Stennis Space Ctr, MS 39529 USA. Univ Houston, Engn Technol Dept, Houston, TX 77204 USA. RP Richter, H (reprint author), Cleveland State Univ, Dept Engn Mech, Stilwell Hall 242,2121 Euclin Ave, Cleveland, OH 44115 USA. EM h.richter@ssuohio.edu; ebarbieri@uh.edu; fernando.figueroa-1@nasa.gov NR 17 TC 0 Z9 0 U1 2 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 0307-904X J9 APPL MATH MODEL JI Appl. Math. Model. PD FEB PY 2005 VL 29 IS 2 BP 195 EP 210 DI 10.1016/j.apm.2004.07.012 PG 16 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications; Mechanics SC Engineering; Mathematics; Mechanics GA 882GM UT WOS:000225927300004 ER PT J AU Feng, HY Van der Wijngaart, R Biswas, R AF Feng, HY Van der Wijngaart, R Biswas, R TI Unstructured adaptive meshes: bad for your memory? SO APPLIED NUMERICAL MATHEMATICS LA English DT Article; Proceedings Paper CT Conference on Adaptive Methods for Partial Differential Equations and Large-Scale Computation (ADAPT 03) CY 2003 CL Rensselaer Polytech Inst, Troy, NY HO Rensselaer Polytech Inst DE nonconforming; spectral element; benchmark; memory access AB The most important performance bottleneck in modern high-end computers is access to memory. Many forms of hardware and software support for reducing memory latency exist, but certain important applications defy these. Examples of such applications are unstructured adaptive (UA) mesh problems, which feature irregular, dynamically changing memory access. We describe a new benchmark program, called UA, for measuring the performance of computer systems when solving such problems. It complements the existing NAS Parallel Benchmarks suite that deals mainly with static, regular-stride memory references. The UA benchmark involves the solution of a stylized heat transfer problem in a cubic domain, discretized on an adaptively refined, unstructured mesh. We describe the numerical and implementation issues, and also present some interesting performance results. (C) 2004 IMACS. Published by Elsevier B.V. All rights reserved. C1 NASA, Ames Res Ctr, NAS Div, Moffett Field, CA 94035 USA. NASA, Ames Res Ctr, CSC, Moffett Field, CA 94035 USA. RP Biswas, R (reprint author), NASA, Ames Res Ctr, NAS Div, Moffett Field, CA 94035 USA. EM fhy@nas.nasa.gov; wijngaar@nas.nasa.gov; rupak.biswas@nasa.gov NR 18 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9274 J9 APPL NUMER MATH JI Appl. Numer. Math. PD FEB PY 2005 VL 52 IS 2-3 BP 153 EP 173 DI 10.1016/j.apnum.2004.08.029 PG 21 WC Mathematics, Applied SC Mathematics GA 886IK UT WOS:000226220200003 ER PT J AU Jain, M Majumder, SB Katiyar, RS Bhalla, AS Miranda, FA Van Keuls, FW AF Jain, M Majumder, SB Katiyar, RS Bhalla, AS Miranda, FA Van Keuls, FW TI Investigations of sol-gel-derived highly (100)-oriented Ba0.5Sr0.5TiO3 : MgO composite thin films for phase-shifter applications SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article ID TUNABLE MICROWAVE APPLICATIONS; BARIUM STRONTIUM-TITANATE; DIELECTRIC-PROPERTIES; EPITAXIAL-GROWTH; MGO; DEPOSITION; CERAMICS; DEVICES; LAALO3 AB Sol - gel deposition of highly oriented Ba0.5Sr0.5TiO3 : MgO composite thin films has shown desirable dielectric constant reduction and higher figure of merit for phase-shifter applications. In this multilayer configuration, MgO distributed homogeneously through the Ba0.5Sr0.5TiO3 (BST50) matrix, and it helped in tailoring the dielectric constant and reducing the loss tangent significantly. In the present study, the high-frequency dielectric behavior of the films has been evaluated by fabricating an eight-element coupled microstrip phase shifter and measuring the degree of phase shift and insertion loss as a function of applied voltage at room temperature. An increase in phase-shifter figure of merit ( degree of phase shift per dB insertion loss) from 28degrees/dB for pure BST50 to 71degrees/dB for a BST50 : MgO film ( at 14 GHz and 333 kV/cm) has been observed. C1 Univ Puerto Rico, Dept Phys, San Juan, PR 00931 USA. Penn State Univ, Mat Res Inst, University Pk, PA 16802 USA. NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Katiyar, RS (reprint author), Univ Puerto Rico, Dept Phys, POB 23 343, San Juan, PR 00931 USA. EM rkatiyar@rrpac.upr.clu.edu OI Jain, Menka/0000-0002-2264-6895 NR 25 TC 8 Z9 8 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING STREET, NEW YORK, NY 10013 USA SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD FEB PY 2005 VL 80 IS 3 BP 645 EP 647 DI 10.1007/s00339-003-2268-4 PG 3 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 877WG UT WOS:000225604800038 ER PT J AU Heldmann, JL Pollard, WH McKay, CP Andersen, DT Toon, OB AF Heldmann, JL Pollard, WH McKay, CP Andersen, DT Toon, OB TI Annual development cycle of an icing deposit and associated perennial spring activity on Axel Heiberg Island, Canadian High Arctic SO ARCTIC ANTARCTIC AND ALPINE RESEARCH LA English DT Article ID EXPEDITION FJORD AB This paper examines the behavior of perennial saline springs and their icings at Expedition Fiord in the Canadian High Arctic during the winter months when temperatures are below the eutectic point of the solution and during the early spring when temperatures are still below freezing but above the eutectic point. The spring outflow begins to freeze when it cools from the discharge temperature which is between -3.5&DEG; C and +6&DEG; C. As ice forms it remains mixed with the brine forming a salty, icy, slush which lines the sides of the flow channel. Networks of pipes and tunnels also allow the brine to flow under and through the icing before being frozen at the icing perimeter. In late winter complete freezing occurs several hundred meters from the springs' outlets. There appears to be incomplete fractionation of salt during the freezing process and the bulk ice contains 30 to 285 ppt salt. The icing reaches its maximum extent in late winter just before temperatures rise above the eutectic point. In April 2002 the icing had dimensions of 300 m by 700 m, an average thickness of 0.5 m and a total mass of approximately 2 X 10(8) kg. This icing mass is consistent with the flow from the springs during the previous 6 mo. C1 Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA. Univ Colorado, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. McGill Univ, Dept Geog, Montreal, PQ H3A 2K6, Canada. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. SETI Inst, Mountain View, CA 94043 USA. Univ Colorado, Program Atmospher & Ocean Sci, Atmospher & Space Phys Lab, Boulder, CO 80309 USA. RP Heldmann, JL (reprint author), Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA. EM jheldmann@mail.arc.nasa.gov NR 18 TC 11 Z9 12 U1 0 U2 3 PU INST ARCTIC ALPINE RES PI BOULDER PA UNIV COLORADO, BOULDER, CO 80309 USA SN 1523-0430 J9 ARCT ANTARCT ALP RES JI Arct. Antarct. Alp. Res. PD FEB PY 2005 VL 37 IS 1 BP 127 EP 135 DI 10.1657/1523-0430(2005)037[0127:ADCOAI]2.0.CO;2 PG 9 WC Environmental Sciences; Geography, Physical SC Environmental Sciences & Ecology; Physical Geography GA 925KH UT WOS:000229051500015 ER PT J AU Pohorille, A Schweighofer, K Wilson, MA AF Pohorille, A Schweighofer, K Wilson, MA TI The origin and early evolution of membrane channels SO ASTROBIOLOGY LA English DT Review DE ion channels; ion transport; folding of membrane proteins; protocells ID INFLUENZA-A VIRUS; DEPENDENT K+ CHANNEL; ION-CHANNEL; CRYSTAL-STRUCTURE; LIPID-BILAYERS; MECHANOSENSITIVE CHANNEL; TRANSMEMBRANE HELICES; POTASSIUM CHANNEL; MOLECULAR-DYNAMICS; ESCHERICHIA-COLI AB The origin and early evolution of ion channels are considered from the point of view that the transmembrane segments of membrane proteins are structurally quite simple and do not require specific sequences to fold. We argue that the transport of solute species, especially ions, required an early evolution of efficient transport mechanisms, and that the emergence of simple ion channels was protobiologically plausible. We also argue that, despite their simple structure, such channels could possess properties that, at the first sight, appear to require markedly greater complexity. These properties can be subtly modulated by local modifications to the sequence rather than global changes in molecular architecture. In order to address the evolution and development of ion channels, we focus on identifying those protein domains that are commonly associated with ion channel proteins and are conserved throughout the three main domains of life (Eukarya, Bacteria, and Archaea). We discuss the potassium-sodium-calcium superfamily of voltage-gated ion channels, mechanosensitive channels, porins, and ABC-transporters and argue that these families of membrane channels have sufficiently universal architectures that they can readily adapt to the diverse functional demands arising during evolution. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Adv Comp Sci Res Inst, Moffett Field, CA 94035 USA. Univ Calif San Francisco, Dept Pharmaceut Chem, San Francisco, CA 94143 USA. RP Pohorille, A (reprint author), NASA, Ames Res Ctr, MS 239-4, Moffett Field, CA 94035 USA. EM pohorill@raphael.arc.nasa.gov NR 115 TC 27 Z9 31 U1 0 U2 23 PU MARY ANN LIEBERT INC PI NEW ROCHELLE PA 140 HUGUENOT STREET, 3RD FL, NEW ROCHELLE, NY 10801 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD FEB PY 2005 VL 5 IS 1 BP 1 EP 17 DI 10.1089/ast.2005.5.1 PG 17 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 896SB UT WOS:000226952700001 PM 15711166 ER PT J AU Dhillon, A Goswami, S Riley, M Teske, A Sogin, M AF Dhillon, A Goswami, S Riley, M Teske, A Sogin, M TI Domain evolution and functional diversification of sulfite reductases SO ASTROBIOLOGY LA English DT Article DE dissimilatory sulfite reductase; anaerobic sulfite reductase; assimilatory sulfite reductase; low-molecular-weight assimilatory sulfite reductase ID SULFATE-REDUCING BACTERIA; BILOPHILA-WADSWORTHIA RZATAU; MULTIPLE LATERAL TRANSFERS; SALMONELLA-TYPHIMURIUM; GEN. NOV.; ARCHAEOGLOBUS-FULGIDUS; CATALYTIC PROPERTIES; ESCHERICHIA-COLI; HYDROGEN-SULFIDE; GENOME SEQUENCE AB Sulfite reductases are key enzymes of assimilatory and dissimilatory sulfur metabolism, which occur in diverse bacterial and archaeal lineages. They share a highly conserved domain "C-X-5-C-n-C-X-3-C" for binding siroheme and iron-sulfur clusters that facilitate electron transfer to the substrate. For each sulfite reductase cluster, the siroheme-binding domain is positioned slightly differently at the N-terminus of dsrA and dsrB, while in the assimilatory proteins the siroheme domain is located at the C-terminus. Our sequence and phylogenetic analysis of the siroheme-binding domain shows that sulfite reductase sequences diverged from a common ancestor into four separate clusters (aSir, alSir, dsr, and asrC) that are biochemically distinct; each serves a different assimilatory or dissimilatory role in sulfur metabolism. The phylogenetic distribution and functional grouping in sulfite reductase clusters (dsrA and dsrB vs. aSiR, asrC, and alSir) suggest that their functional diversification during evolution may have preceded the bacterial/archaeal divergence. C1 NASA, Astrobiol Inst, Biol Marine Lab, Josephine Bay Paul Ctr Comparat Mol Biol & Evolut, Woods Hole, MA 02543 USA. Univ N Carolina, Dept Marine Sci, Chapel Hill, NC USA. RP Sogin, M (reprint author), NASA, Astrobiol Inst, Biol Marine Lab, Josephine Bay Paul Ctr Comparat Mol Biol & Evolut, 7 MBL St, Woods Hole, MA 02543 USA. EM sogin@mbl.edu NR 53 TC 29 Z9 30 U1 1 U2 16 PU MARY ANN LIEBERT INC PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD FEB PY 2005 VL 5 IS 1 BP 18 EP 29 DI 10.1089/ast.2005.5.18 PG 12 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 896SB UT WOS:000226952700002 PM 15711167 ER PT J AU Lau, E Nash, CZ Vogler, DR Cullings, KW AF Lau, E Nash, CZ Vogler, DR Cullings, KW TI Molecular diversity of cyanobacteria inhabiting coniform structures and surrounding mat in a yellowstone hot spring SO ASTROBIOLOGY LA English DT Article DE lithified coniform structures; cyanobacteria; hot spring stromatolites ID GRADIENT GEL-ELECTROPHORESIS; RIBOSOMAL-RNA SEQUENCES; MICROBIAL MATS; PHYLOGENETIC-RELATIONSHIPS; COLORADO PLATEAU; WARRAWOONA GROUP; COMMUNITY; STROMATOLITES; PHOTOSYNTHESIS; MICROORGANISMS AB Lithified coniform structures are common within cyanobacterial mats in Yellowstone National Park hot springs. It is unknown whether these structures and the mats from which they develop are inhabited by the same cyanobacterial populations. Denaturing gradient gel electrophoresis and sequencing and phylogenetic analysis of 16S rDNA was used to determine whether (1) three different morphological types of lithified coniform structures are inhabited by different cyanobacterial species, (2) these species are partitioned along a vertical gradient of these structures, and (3) lithified and non-lithified sections of mat are inhabited by different cyanobacterial species. Our results, based on multiple samplings, indicate that the cyanobacterial community compositions in the three lithified morphological types were identical and lacked any vertical differentiation. However, lithified and non-lithified portions of the same mat were inhabited by distinct and different populations of cyanobacteria. Cyanobacteria inhabiting lithified structures included at least one undefined Oscillatorialean taxon, which may represent the dominant cyanobacteria genus in lithified coniform stromatolites, Phormidium, three Synechococcus-like species, and two unknown cyanobacterial taxa. In contrast, the surrounding mats contained four closely related Synechococcus-like species. Our results indicate that the distribution of lithified coniform stromatolites may be dependent on the presence of one or more microorganisms, which are phylogenetically different from those inhabiting surrounding non-lithified mats. C1 Harvard Univ, Dept Organism & Evolutionary Biol, Cambridge, MA 02138 USA. CALTECH, Dept Geol, Pasadena, CA 91125 USA. USDA, Forest Serv, Inst Forest Genet, Davis, CA USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Lau, E (reprint author), Harvard Univ, Dept Organism & Evolutionary Biol, 16 Divin Ave, Cambridge, MA 02138 USA. EM elau@oeb.harvard.edu NR 54 TC 17 Z9 18 U1 1 U2 6 PU MARY ANN LIEBERT INC PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 1531-1074 J9 ASTROBIOLOGY JI Astrobiology PD FEB PY 2005 VL 5 IS 1 BP 83 EP 92 DI 10.1089/ast.2005.5.83 PG 10 WC Astronomy & Astrophysics; Biology; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Life Sciences & Biomedicine - Other Topics; Geology GA 896SB UT WOS:000226952700007 PM 15711172 ER PT J AU Barger, AJ Cowie, LL Mushotzky, RF Yang, Y Wang, WH Steffen, AT Capak, P AF Barger, AJ Cowie, LL Mushotzky, RF Yang, Y Wang, WH Steffen, AT Capak, P TI The cosmic evolution of hard X-ray-selected active galactic nuclei SO ASTRONOMICAL JOURNAL LA English DT Review DE cosmology : observations; galaxies : active; galaxies : distances and redshifts; galaxies : evolution; galaxies : formation ID DEEP FIELD-NORTH; LINE SEYFERT-1 GALAXIES; SUPERMASSIVE BLACK-HOLES; QSO REDSHIFT SURVEY; DIGITAL SKY SURVEY; QUASAR SURVEY SBQS; LUMINOSITY FUNCTION; STARBURST GALAXIES; LOCKMAN-HOLE; OPTICAL IDENTIFICATIONS AB We use highly spectroscopically complete deep and wide-area Chandra surveys to determine the cosmic evolution of hard X-ray-selected active galactic nuclei (AGNs). For the deep fields, we supplement the spectroscopic redshifts with photometric redshifts to assess where the unidentified sources are likely to lie. We find that the median redshifts are fairly constant with X-ray flux at z similar to 1. We classify the optical spectra and measure the FWHM line widths. Most of the broad-line AGNs show essentially no visible absorption in X-rays, whereas the sources without broad lines (FWHM < 2000 km s(-1); "optically narrow" AGNs) show a wide range of absorbing column densities. We determine hard X-ray luminosity functions for all spectral types with L-X greater than or equal to 10(42) ergs s(-1) and for broad-line AGNs alone. At z < 1.2, both are well described by pure luminosity evolution, with L. evolving as (1 + Z)(3.2+/-0.8) for all spectral types and as (1 + Z)(3.0+/-1.0) for broad-line AGNs alone. Thus, all AGNs drop in luminosity by almost an order of magnitude over this redshift range. We show that this observed drop is due to AGN downsizing rather than to an evolution in the accretion rates onto the supermassive black holes. We directly compare our broad-line AGN hard X-ray luminosity functions with the optical QSO luminosity functions and find that at the bright end they agree extremely well at all redshifts. However, the optical QSO luminosity functions do not probe faint enough to see the downturn in the broad-line AGN hard X-ray luminosity functions and even appear to be missing some sources at the lowest luminosities they probe. We find that broad-line AGNs dominate the number densities at the higher X-ray luminosities, while optically narrow AGNs dominate at the lower X-ray luminosities. We rule out galaxy dilution as a partial explanation for this effect by measuring the nuclear UV/optical properties of the Chandra sources using the Hubble Space Telescope Advanced Camera for Surveys GOODS-North data. The UV/optical nuclei of the optically narrow AGNs are much weaker than expected if the optically narrow AGNs were similar to the broad-line AGNs. We therefore postulate the need for a luminosity-dependent unified model. An alternative possibility is that the broad-line AGNs and the optically narrow AGNs are intrinsically different source populations. We cover both interpretations by constructing composite spectral energy distributions-including long-wavelength data from the mid-infrared to the submillimeter-by spectral type and by X-ray luminosity. We use these spectral energy distributions to infer the bolometric corrections (from hard X-ray luminosities to bolometric luminosities) needed to map the accretion history. We determine the accreted supermassive black hole mass density for all spectral types and for broad-line AGNs alone, using the observed evolution of the hard X-ray energy density production rate and our inferred bolometric corrections. We find that only about one-half to one-quarter of the supermassive black hole mass density was fabricated in broad-line AGNs. Using either recent optical QSO luminosity function determinations or our broadline AGN hard X-ray luminosity function determinations, we measure an accreted supermassive black hole mass density that is a factor of almost 2 lower than that measured by previous work, assuming epsilon = 0. 1. This leaves room for obscured accretion when compared with the local supermassive black hole mass density. In fact, we find reasonable agreement between the accreted supermassive black hole mass density from all spectral types and the local supermassive black hole mass density, assuming epsilon approximate to 0.1-0.2. However, there is little room for further obscured sources or for low-efficiency accretion periods. 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. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Univ Wisconsin, Dept Astron, 475 N Charter St, Madison, WI 53706 USA. NR 102 TC 339 Z9 340 U1 0 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD FEB PY 2005 VL 129 IS 2 BP 578 EP 609 DI 10.1086/426915 PG 32 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 895HY UT WOS:000226852900003 ER PT J AU Davidson, K Martin, J Humphreys, RM Ishibashi, K Gull, TR Stahl, O Weis, K Hillier, DJ Damineli, A Corcoran, M Hamann, F AF Davidson, K Martin, J Humphreys, RM Ishibashi, K Gull, TR Stahl, O Weis, K Hillier, DJ Damineli, A Corcoran, M Hamann, F TI A change in the physical state of eta Carinae? SO ASTRONOMICAL JOURNAL LA English DT Article DE binaries : general; line : profiles; stars : individual (eta Carinae); stars : variables : other; stars : winds; outflows ID LOW-EXCITATION EVENT; LONG-PERIOD BINARY; STELLAR WIND; SPECTROSCOPY; VARIABILITY; PARAMETERS; VARIABLES; COMPANION; CYCLE; CAR AB During eta Car's spectroscopic event in mid-2003, the stellar wind's bright Halpha and Hbeta emission lines temporarily had a distinctive shape unlike that reported on any previous occasion and particularly unlike the 1997-1998 event. Evidently the structure of the wind changed between 1997 and 2003. Combining this with other evidence, we suspect that the star may now be passing through a rapid stage in its recovery from the Great Eruption seen 160 years ago. In any case, the data indicate that successive spectroscopic events differ, and the hydrogen line profiles are quantitative clues to the abnormal structure of the wind during a spectroscopic event. C1 Univ Minnesota, Sch Phys & Astron, Minneapolis, MN 55455 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Landessternwarte Heidelberg, D-69117 Heidelberg, Germany. Ruhr Univ Bochum, Astron Inst, D-44780 Bochum, Germany. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Univ Sao Paulo, IAG, BR-05508900 Sao Paulo, Brazil. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. RP Davidson, K (reprint author), Univ Minnesota, Sch Phys & Astron, 116 Church St, Minneapolis, MN 55455 USA. EM kd@astro.umn.edu RI Gull, Theodore/D-2753-2012; Damineli, Augusto/D-8210-2012 OI Gull, Theodore/0000-0002-6851-5380; Damineli, Augusto/0000-0002-7978-2994 NR 42 TC 45 Z9 45 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 FEB PY 2005 VL 129 IS 2 BP 900 EP 906 DI 10.1086/427132 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 895HY UT WOS:000226852900024 ER PT J AU Krist, JE Ardila, DR Golimowski, DA Clampin, M Ford, HC Illingworth, GD Hartig, GF Bartko, F Benitez, N Blakeslee, JP Bouwens, RJ Bradley, LD Broadhurst, TJ Brown, RA Burrows, CJ Cheng, ES Cross, NJG Demarco, R Feldman, PD Franx, M Goto, T Gronwall, C Holden, B Homeier, N Infante, L Kimble, RA Lesser, MP Martel, AR Mei, S Menanteau, F Meurer, GR Miley, GK Motta, V Postman, M Rosati, P Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W AF Krist, JE Ardila, DR Golimowski, DA Clampin, M Ford, HC Illingworth, GD Hartig, GF Bartko, F Benitez, N Blakeslee, JP Bouwens, RJ Bradley, LD Broadhurst, TJ Brown, RA Burrows, CJ Cheng, ES Cross, NJG Demarco, R Feldman, PD Franx, M Goto, T Gronwall, C Holden, B Homeier, N Infante, L Kimble, RA Lesser, MP Martel, AR Mei, S Menanteau, F Meurer, GR Miley, GK Motta, V Postman, M Rosati, P Sirianni, M Sparks, WB Tran, HD Tsvetanov, ZI White, RL Zheng, W TI Hubble Space Telescope Advanced Camera for Surveys coronagraphic imaging of the AU microscopii debris disk SO ASTRONOMICAL JOURNAL LA English DT Article DE circumstellar matter; stars : individual (AU Microscopii) ID PICTORIS DUST DISK; BETA-PICTORIS; CIRCUMSTELLAR DISK; STARS; ASYMMETRIES; DISCOVERY AB We present Hubble Space Telescope Advanced Camera for Surveys multicolor coronagraphic images of the recently discovered edge-on debris disk around the nearby (similar to10 pc) M dwarf AU Microscopii. The disk is seen between r = 0".75 and 15" (7.5-150 AU) from the star. It has a thin midplane with a projected FWHM thickness of 2.5-3.5 AU within r < 50 AU of the star that increases to 6.5-9 AU at r similar to 75 AU. The disk's radial brightness profile is generally flat for r < 15 AU, then decreases gradually (I proportional to r(1.8)) out to r approximate to 43 AU, beyond which it falls rapidly (I proportional to r(-4.7)). Within 50 AU the midplane is straight and aligned with the star, and beyond that it deviates by similar to3degrees, resulting in a bowed appearance that was also seen in ground-based images. Three-dimensional modeling of the disk shows that the inner region (r < 50 AU) is inclined to the line of sight by less than 1degrees and the outer disk by similar to3degrees. The inclination of the outer disk and moderate forward scattering (g approximate to 0.4) can explain the apparent bow. The intrinsic, deprojected FWHM thickness is 1.5-10 AU, increasing with radius. The models indicate that the disk is clear of dust within similar to12 AU of the star, in general agreement with the previous prediction of 17 AU based on the infrared spectral energy distribution. The disk is blue, being 60% brighter at B than I relative to the star. One possible explanation for this is that there is a surplus of very small grains compared with other imaged debris disks that have more neutral or red colors. This may be due to the low radiation pressure exerted by the late-type star. Observations at two epochs show that an extended source seen along the midplane is a background galaxy. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Calif Santa Cruz, Lick Observ, UCO, Santa Cruz, CA 95064 USA. Bartko Sci & Technol, Brighton, CO 80602 USA. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Conceptual Analyt LLC, Glenn Dale, MD 20769 USA. Leiden Observ, NL-2300 RA Leiden, Netherlands. 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. European So Observ, D-85748 Garching, Germany. WM Keck Observ, Kamuela, HI 96743 USA. RP Krist, JE (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. RI White, Richard/A-8143-2012; Clampin, mark/D-2738-2012; Kimble, Randy/D-5317-2012; OI Benitez, Narciso/0000-0002-0403-7455; Blakeslee, John/0000-0002-5213-3548 NR 18 TC 91 Z9 91 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 FEB PY 2005 VL 129 IS 2 BP 1008 EP 1017 DI 10.1086/426755 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 895HY UT WOS:000226852900035 ER PT J AU Polomski, EF Woodward, CE Holmes, EK Butner, HM Lynch, DK Russell, RW Sitko, ML Wooden, DH Telesco, CM Pina, R AF Polomski, EF Woodward, CE Holmes, EK Butner, HM Lynch, DK Russell, RW Sitko, ML Wooden, DH Telesco, CM Pina, R TI Dust morphology and composition in FU Orionis systems SO ASTRONOMICAL JOURNAL LA English DT Review DE infrared : stars; planetary systems : protoplanetary disks; stars : pre-main-sequence ID HERBIG-AE/BE STARS; Z-CANIS-MAJORIS; SPECTRAL IRRADIANCE CALIBRATION; YOUNG STELLAR OBJECTS; MAIN-SEQUENCE STARS; HARO ENERGY-SOURCES; T-TAURI STARS; INFRARED OBSERVATIONS; MOLECULAR OUTFLOWS; BIPOLAR OUTFLOW AB FU Orionis stars are a small group of pre-main-sequence stars known for large-amplitude optical variability. These objects also exhibit rnultiwavelength phenomena suggestive of active accretion from a circumstellar disk. We present high spatial resolution mid-IR imaging and spectroscopy, submillimeter photometry, and 3-4 mum photometry of four FU Ori-class objects, RNO 1B and C, Z CMa, and Par 21, and one object classified as a pre-FU Ori star, V380 Ori. We resolve multiple IR sources and extended emission in the RNO 1B/C system, and we discuss in detail their association with disk activity and the source of the Infrared Astronomical Satellite far-IR and radio maser emission in this field. We derive dust temperatures and masses for all sources and discuss how dust composition and morphology is related to the evolutionary stage of these objects. C1 Univ Minnesota, Dept Astron, Minneapolis, MN 55455 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Arizona, Steward Observ, Submillimeter Telescope Observ, Tucson, AZ 85721 USA. Aerosp Corp, Space Sci Applicat Lab, Los Angeles, CA 90009 USA. Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. Univ Florida, Dept Astron, Gainesville, FL 32611 USA. RP Univ Minnesota, Dept Astron, 116 Church St SE, Minneapolis, MN 55455 USA. EM elwood@astro.umn.edu; chelsea@astro.umn.edu; holmes@jpl.nasa.gov; hbutner@jach.hawaii.edu; david.k.lynch@aero.org; ray.w.russell@aero.org; sitko@physics.uc.edu; wooden@delphinus.arc.nasa.gov; telesco@astro.ufl.edu OI Butner, Harold/0000-0003-4899-2064 NR 109 TC 6 Z9 6 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 EI 1538-3881 J9 ASTRON J JI Astron. J. PD FEB PY 2005 VL 129 IS 2 BP 1035 EP 1048 DI 10.1086/426907 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 895HY UT WOS:000226852900037 ER PT J AU Petrov, L Kovalev, YY Fomalont, E Gordon, D AF Petrov, L Kovalev, YY Fomalont, E Gordon, D TI The third VLBA Calibrator Survey: VCS3 SO ASTRONOMICAL JOURNAL LA English DT Article DE astrometry; catalogs; quasars : general; radio continuum : general; reference systems; techniques : interferometric ID CELESTIAL REFERENCE FRAME; RADIO-SOURCES; SKY SURVEY; CATALOG; INTERFEROMETRY; SELECTION; SPECTRUM; GHZ AB We present the third extension to the Very Long Baseline Array (VLBI) Calibrator Survey, containing 360 new sources not previously observed with very long baseline interferometry (VLBI). The survey, based on three 24 hour VLBA observing sessions, fills the areas on the sky above declination -45degrees where the calibrator density is less than one source within a 4degrees radius disk at any given direction. The positions were derived from astrometric analysis of the group delays determined at 2.3 and 8.6 GHz frequency bands using the CALC/SOLVE software package. The VCS3 catalog of source positions, plots of correlated flux density versus length of projected baseline, and contour plots and FITS files of naturally weighted CLEAN images, as well as calibrated visibility function files, are available electronically from the Goddard Geodetic VLBI Group. C1 NVI Inc, Greenbelt, MD 20770 USA. Natl Radio Astron Observ, Green Bank, WV 24944 USA. PN Lebedev Phys Inst, Ctr Astro Space, Moscow 117997, Russia. Natl Radio Astron Observ, Charlottesville, VA 22903 USA. NASA, Goddard Space Flight Ctr, Raytheon ITSS, Greenbelt, MD 20771 USA. RP Petrov, L (reprint author), NVI Inc, 7257D Hanover Pkwy, Greenbelt, MD 20770 USA. EM Leonid.Petrov@lpetrov.net; ykovalev@nrao.edu; efomalon@nrao.edu; dgg@leo.gsfc.nasa.gov RI Kovalev, Yuri/J-5671-2013 OI Kovalev, Yuri/0000-0001-9303-3263 NR 28 TC 86 Z9 88 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 FEB PY 2005 VL 129 IS 2 BP 1163 EP 1170 DI 10.1086/426920 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 895HY UT WOS:000226852900044 ER PT J AU Milani, A Sansaturio, ME Tommei, G Arratia, O Chesley, SR AF Milani, A Sansaturio, ME Tommei, G Arratia, O Chesley, SR TI Solutions for asteroid orbits: Computational procedure and applications SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE minor planets, asteroids; celestial mechanics; astrometry; surveys ID IDENTIFICATION PROBLEM AB We describe the Multiple Solutions Method, a one-dimensional sampling of the six-dimensional orbital confidence region that is widely applicable in the field of asteroid orbit determination. In many situations there is one predominant direction of uncertainty in an orbit determination or orbital prediction, i.e., a "weak" direction. The idea is to record Multiple Solutions by following this, typically curved, weak direction, or Line Of Variations (LOV). In this paper we describe the method and give new insights into the mathematics behind this tool. We pay particular attention to the problem of how to ensure that the coordinate systems are properly scaled so that the weak direction really reflects the intrinsic direction of greatest uncertainty. We also describe how the multiple solutions can be used even in the absence of a nominal orbit solution, which substantially broadens the realm of applications. There are numerous applications for multiple solutions; we discuss a few problems in asteroid orbit determination and prediction where we have had good success with the method. In particular, we show that multiple solutions can be used effectively for potential impact monitoring, preliminary orbit determination, asteroid identification, and for the recovery of lost asteroids. C1 Univ Pisa, Dipartimento Matemat, I-56127 Pisa, Italy. Univ Valladolid, ETS Ingn Ind, E-47011 Valladolid, Spain. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Univ Pisa, Dipartimento Matemat, Via Buonarroti 2, I-56127 Pisa, Italy. EM milani@mail.dm.unipi.it; meusan@eis.uva.es; tommei@mail.dm.unipi.it; oscarr@eis.uva.es; steve.chesley@jpl.nasa.gov RI Arratia, Oscar/B-2599-2017; OI Arratia, Oscar/0000-0001-6825-6895; Tommei, Giacomo/0000-0002-9593-613X NR 13 TC 37 Z9 36 U1 2 U2 4 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD FEB PY 2005 VL 431 IS 2 BP 729 EP 746 DI 10.1051/0004-6361:20041737 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 894ML UT WOS:000226795800035 ER PT J AU Prinja, RK Massa, D Searle, SC AF Prinja, RK Massa, D Searle, SC TI The ionization structure of early-B supergiant winds SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars : early-type; stars : mass-loss; ultraviolet : stars ID O-STARS; MAGELLANIC CLOUDS; FAR-ULTRAVIOLET; STELLAR WINDS; TEMPERATURES AB We present empirically determined ionization conditions for the winds of 106 luminous B0 to B5 stars observed by IUE. The UV wind lines are modelled to extract products of mass- loss rates times ionization fractions ((M) over dot q(i)(w), where w = nu/nu(infinity)) for N V, C IV, Si IV, Si III, Al III and C II. We describe the general behaviour of the (M) over dot q(i)(w) and their ratios, demonstrating that the wind ionization increases with distance from the star, contrary to recent findings for O star winds. Using empirical mass- loss rates (from Halpha observations) and model prescriptions, we derive mean q(i)(w) values integrated over the wind, [q(i)]. These [q(i)] are quite small, never exceeding 15% for Al III or 2% for Si IV. This is surprising, since the [q(i)] for these ions clearly peak within the observed spectral range. We conclude that the low [q(i)] arise because the [(M) over dot q(i)] are underestimated by the wind models, which assume that the outflows are smooth when they are, in fact, highly structured. C1 UCL, Dept Phys & Astron, London WC1E 6BT, England. NASA, Goddard Space Flight Ctr, SGT Inc, Greenbelt, MD 20771 USA. RP UCL, Dept Phys & Astron, Gower St, London WC1E 6BT, England. EM rkp@star.ucl.ac.uk; massa@taotaomona.gsfc.nasa.gov; scs@star.ucl.ac.uk NR 20 TC 20 Z9 20 U1 0 U2 2 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 FEB PY 2005 VL 430 IS 2 BP L41 EP L44 DI 10.1051/0004-6361:200400129 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 889TE UT WOS:000226464700006 ER PT J AU Snyder, LE Lovas, FJ Hollis, JM Friedel, DN Jewell, PR Remijan, A Ilyushin, VV Alekseev, EA Dyubko, SF AF Snyder, LE Lovas, FJ Hollis, JM Friedel, DN Jewell, PR Remijan, A Ilyushin, VV Alekseev, EA Dyubko, SF TI A rigorous attempt to verify interstellar glycine SO ASTROPHYSICAL JOURNAL LA English DT Article DE ISM : abundances; ISM : clouds; ISM : individual (Sagittarius B2(N-LMH), Orion Kleinmann-Low, W51 e1/e2); ISM : molecules; radio lines : ISM ID MARYLAND-ASSOCIATION ARRAY; SPECTRAL-LINE SURVEY; HOT MOLECULAR CORES; ACETIC-ACID; OBSERVATIONAL DATA; SAGITTARIUS B2; FORMIC-ACID; SEARCH; MILLIMETER; CONFORMER AB In 2003, Kuan and coworkers reported the detection of interstellar glycine (NH2CH2COOH) based on observations of 27 lines in 19 different spectral bands in one or more of the sources Sgr B2(N-LMH), Orion KL, and W51 e1/e2. They supported their detection report with rotational temperature diagrams for all three sources. In this paper we present essential criteria that can be used in a straightforward analysis technique to confirm the identity of an interstellar asymmetric rotor such as glycine. We use new laboratory measurements of glycine as a basis for applying this analysis technique, both to our previously unpublished 12 m telescope data and to the previously published Swedish-ESO Submillimetre Telescope (SEST) data of Nummelin and colleagues. We conclude that key lines necessary for an interstellar glycine identification have not yet been found. We identify some common molecular candidates that should be examined further as more likely carriers of several of the lines reported as glycine. Finally, we illustrate that a rotational temperature diagram used without the support of correct spectroscopic assignments is not a reliable tool for the identification of interstellar molecules. C1 Univ Illinois, Dept Astron, Urbana, IL 61801 USA. Natl Inst Stand & Technol, Opt Technol Div, Gaithersburg, MD USA. NASA, Goddard Space Flight Ctr, Earth & Space Data Comp Div, Greenbelt, MD 20771 USA. Natl Radio Astron Observ, Green Bank, WV 24944 USA. Natl Acad Sci Ukraine, Inst Radio Astron, UA-61002 Kharkov, Ukraine. RP Snyder, LE (reprint author), Univ Illinois, Dept Astron, 1002 W Green St, Urbana, IL 61801 USA. EM snyder@astro.uiuc.edu; lovas@nist.gov; jan.m.hollis@gsfc.nasa.gov; friedel@astro.uiuc.edu; pjewell@nrao.edu; aremijan@pop900.gsfc.nasa.gov; ilyushin@rian.ira.kharkov.ua; alekseev@rian.ira.kharkov.ua NR 45 TC 174 Z9 175 U1 1 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 FEB 1 PY 2005 VL 619 IS 2 BP 914 EP 930 DI 10.1086/426677 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 891NZ UT WOS:000226589100020 ER PT J AU Ballantyne, DR Turner, NJ Young, AJ AF Ballantyne, DR Turner, NJ Young, AJ TI X-ray reflection from inhomogeneous accretion disks. II. Emission-line variability and implications for reverberation mapping SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; instabilities; line : formation; radiative transfer; X-rays : general ID ACTIVE GALACTIC NUCLEI; RADIATION MAGNETOHYDRODYNAMICS CODE; 2 SPACE DIMENSIONS; IRON K EMISSION; BLACK-HOLE MASS; FEK-ALPHA LINE; SEYFERT-1 GALAXIES; PHOTON BUBBLES; XMM-NEWTON; ASTROPHYSICAL FLOWS AB One of the principal scientific objectives of the upcoming Constellation-X mission is to attempt to map the inner regions of accretion disks around black holes in Seyfert galaxies by reverberation mapping of the Fe Kalpha fluorescence line. This area of the disk is likely to be radiation pressure dominated and subject to various dynamical instabilities. Here, we show that density inhomogeneities in the disk atmosphere resulting from the photon bubble instability (PBI) can cause rapid changes in the X-ray reflection features, even when the illuminating flux is constant. Using a simulation of the development of the PBI, we find that for the disk parameters chosen, the Fe Kalpha and O VIII Lyalpha lines vary on timescales as short as a few hundredths of an orbital period. In response to the changes in accretion disk structure, the Fe Kalpha equivalent width (EW) shows variations as large as similar to100 eV. The magnitude and direction (positive or negative) of the changes depends on the ionization state of the atmosphere. The largest changes are found when the disk is moderately ionized. The O VIII EW varies by tens of eV and exhibits plenty of rapid, low-amplitude changes. This effect provides a natural explanation for some observed instances of short-timescale Fe Kalpha variability that was uncorrelated with the continuum (e.g., Mrk 841). New predictions for Fe Kalpha reverberation mapping should be made that include the effects of this accretion disk-driven line variability and a variable ionization state. Reflection spectra averaged over the evolution of the instability are well fitted by constant-density models in the 2-10 keV region. C1 Canadian Inst Theoret Astrophys, McLennan Labs, Toronto, ON M5S 3H8, Canada. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. MIT, Ctr Space Res, Cambridge, MA 02139 USA. RP Ballantyne, DR (reprint author), Canadian Inst Theoret Astrophys, McLennan Labs, 60 St George St, Toronto, ON M5S 3H8, Canada. EM ballantyne@cita.utoronto.ca; neal.turner@jpl.nasa.gov; ayoung@space.mit.edu NR 51 TC 13 Z9 13 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 FEB 1 PY 2005 VL 619 IS 2 BP 1028 EP 1035 DI 10.1086/426578 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 891NZ UT WOS:000226589100032 ER PT J AU Barkats, D Bischoff, C Farese, P Fitzpatrick, L Gaier, T Gundersen, JO Hedman, MM Hyatt, L McMahon, JJ Samtleben, D Staggs, ST Vanderlinde, K Winstein, B AF Barkats, D Bischoff, C Farese, P Fitzpatrick, L Gaier, T Gundersen, JO Hedman, MM Hyatt, L McMahon, JJ Samtleben, D Staggs, ST Vanderlinde, K Winstein, B TI First measurements of the polarization of the cosmic microwave background radiation at small angular scales from CAPMAP SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology : observations ID PROBE WMAP OBSERVATIONS; ANISOTROPY; TEMPERATURE; EMISSION; SPECTRUM; FIRAS AB Polarization results from the Cosmic Anisotropy Polarization MAPper ( CAPMAP) experiment are reported. These are based on 433 hr, after cuts, observing a 2 deg(2) patch around the north celestial pole with four 90 GHz correlation polarimeters coupled to optics defining 4 ' beams. The E- mode flat band- power anisotropy within l = 940 (+330)(-300) is measured as 66(-39)(+53) muK(2); the 95% confidence level upper limit for B- mode power within l = 1050(-520)(+590) is measured as 38 muK(2). C1 Princeton Univ, Joseph Henry Labs, Dept Phys, Princeton, NJ 08544 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Miami, Dept Phys, Coral Gables, FL 33146 USA. Univ Chicago, Kavli Inst Cosmol Phys, Chicago, IL 60637 USA. RP Samtleben, D (reprint author), Univ Chicago, Kavli Inst Cosmol Phys, 5641 S Ingleside Ave, Chicago, IL 60637 USA. EM dorothea@kicp.uchicago.edu OI Barkats, Denis/0000-0002-8971-1954; Bischoff, Colin/0000-0001-9185-6514 NR 21 TC 79 Z9 79 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 FEB 1 PY 2005 VL 619 IS 2 BP L127 EP L130 DI 10.1086/428285 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 891OB UT WOS:000226589300001 ER PT J AU Hurley, K Stern, B Kommers, J Cline, T Mazets, E Golenetskii, S Trombka, J McClanahan, T Goldsten, J Feroci, M Frontera, F Guidorzi, C Montanari, E Lewin, W Meegan, C Fishman, G Kouveliotou, C Sinha, S Seetha, S AF Hurley, K Stern, B Kommers, J Cline, T Mazets, E Golenetskii, S Trombka, J McClanahan, T Goldsten, J Feroci, M Frontera, F Guidorzi, C Montanari, E Lewin, W Meegan, C Fishman, G Kouveliotou, C Sinha, S Seetha, S TI The Interplanetary Network supplement to the BATSE catalogs of untriggered cosmic gamma-ray bursts SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE catalogs; gamma rays : bursts ID ARRIVAL-TIME LOCALIZATIONS; PIONEER-VENUS-ORBITER; ULYSSES SUPPLEMENT; GRANAT/WATCH CATALOG; DECEMBER 1989; INSTRUMENT; SATELLITE; MONITOR; MISSION; PHEBUS AB We present Interplanetary Network (IPN) detection and localization information for 211 gamma-ray bursts (GRBs) observed as untriggered events by the Burst and Transient Source Experiment (BATSE) and published in catalogs by Kommers et al. and Stern et al. IPN confirmations have been obtained by analyzing the data from 11 experiments. For any given burst observed by BATSE and one other distant spacecraft, arrival time analysis (or "triangulation'') results in an annulus of possible arrival directions whose half-width varies between 14" and 5degrees6, depending on the intensity, time history, and arrival direction of the burst, as well as the distance between the spacecraft. This annulus generally intersects the BATSE error circle, resulting in a reduction of the area of up to a factor of similar to650. When three widely separated spacecraft observed a burst, the result is an error box whose area is as much as 30,000 times smaller than that of the BATSE error circle. Because the IPN instruments are considerably less sensitive than BATSE, they generally did not detect the weakest untriggered bursts but did detect the more intense ones, which failed to trigger BATSE when the trigger was disabled. In a few cases, we have been able to identify the probable origin of bursts as soft gamma repeaters. The vast majority of the IPN-detected events, however, are GRBs, and the confirmation of them validates many of the procedures utilized to detect BATSE untriggered bursts. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Russian Acad Sci, Inst Nucl Res, Moscow 117312, Russia. PN Lebedev Phys Inst, Ctr Astro Space, Moscow 117810, Russia. Stockholm Observ, SCFAB, SE-10691 Stockholm, Sweden. MIT, Lincoln Lab, Lexington, MA 02420 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. Johns Hopkins Univ, Appl Phys Lab, Laurel, MD 20723 USA. CNR, Ist Astrofis Spaziale, Area Ric Tor Vergata, I-00133 Rome, Italy. CNR, Ist Astrofis Spaziale & Fis Cosm, Sez Bologna, I-40129 Bologna, Italy. Univ Ferrara, Dipartimento Fis, I-44100 Ferrara, Italy. Liverpool John Moores Univ, Astrophys Res Inst, Birkenhead CH41 1LD, Merseyside, England. MIT, Ctr Space Res, Cambridge, MA 02139 USA. NASA, MSFC, Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA. ISRO, Satellite Ctr, Space Astron & Instrumentat Div, Bangalore 560017, Karnataka, India. RP Hurley, K (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. EM khurley@ssl.berkeley.edu RI McClanahan, Timothy/C-8164-2012; Golenetskii, Sergey/B-3818-2015; OI Feroci, Marco/0000-0002-7617-3421 NR 28 TC 16 Z9 16 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0067-0049 J9 ASTROPHYS J SUPPL S JI Astrophys. J. Suppl. Ser. PD FEB PY 2005 VL 156 IS 2 BP 217 EP 226 DI 10.1086/426671 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890JZ UT WOS:000226508800005 ER PT J AU de Paz, AG Madore, BF AF de Paz, AG Madore, BF TI Palomar/Las Campanas Imaging Atlas of blue compact dwarf galaxies. II. Surface photometry and the properties of the underlying stellar population SO ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES LA English DT Article DE atlases; galaxies : dwarf; galaxies : evolution; galaxies : fundamental parameters; galaxies : photometry; galaxies : starburst ID STAR-FORMATION HISTORY; ELLIPTIC GALAXIES; MULTIBAND ANALYSIS; OPTICAL STRUCTURE; VIRGO CLUSTER; MRK 86; SAMPLE; EVOLUTION; DECOMPOSITION; CONSTRAINTS AB We present the results from an analysis of surface photometry of B, R, and Halpha images of a total of 114 nearby galaxies (v(helio) < 4000 km s(-1)) drawn from the Palomar/Las Campanas Imaging Atlas of blue compact dwarf (BCD) galaxies. Surface brightness and color profiles for the complete sample have been obtained. We determine the exponential and Sersic profiles that best fit the surface brightness distribution of the underlying stellar population detected in these galaxies. We also compute the (B-R) color and total absolute magnitude of the underlying stellar population and compared them to the integrated properties of the galaxies in the sample. Our analysis shows that the (B-R) color of the underlying population is systematically redder than the integrated color, except in those galaxies where the integrated colors are strongly contaminated by line and nebular-continuum emission. We also find that galaxies with relatively red underlying stellar populations [ typically (B-R) &GE; 1 mag] show structural properties compatible with those of dwarf elliptical galaxies (i.e., a smooth light distribution, fainter extrapolated central surface brightness, and larger scale lengths than BCD galaxies with blue underlying stellar populations). At least &SIM;15% of the galaxies in the sample are compatible with being dwarf elliptical (dE) galaxies experiencing a burst of star formation. For the remaining BCD galaxies in the sample we do not find any correlation between the recent star formation activity and their structural differences with respect to other types of dwarf galaxies. C1 Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. CALTECH, NASA IPAC Extragalact Database, Pasadena, CA 91125 USA. RP de Paz, AG (reprint author), Observ Carnegie Inst Washington, 813 Santa Barbara St, Pasadena, CA 91101 USA. EM agpaz@ociw.edu; barry@ipac.caltech.edu RI Gil de Paz, Armando/J-2874-2016 OI Gil de Paz, Armando/0000-0001-6150-2854 NR 40 TC 61 Z9 61 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 FEB PY 2005 VL 156 IS 2 BP 345 EP 360 DI 10.1086/427068 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890JZ UT WOS:000226508800012 ER PT J AU Serrador, JM Schlegel, TT Black, FO Wood, SJ AF Serrador, JM Schlegel, TT Black, FO Wood, SJ TI Cerebral hypoperfusion precedes nausea during centrifugation SO AVIATION SPACE AND ENVIRONMENTAL MEDICINE LA English DT Article DE cerebral blood flow; vestibular; hypergravity cerebrovasculature ID CALORIC VESTIBULAR STIMULATION; BLOOD-FLOW AUTOREGULATION; TRANSCRANIAL DOPPLER; ORTHOSTATIC INTOLERANCE; PARABOLIC FLIGHT; ARTERY; VELOCITY; HUMANS AB Nausea and motion sickness are important operational concerns for aviators and astronauts. Understanding the underlying mechanisms associated with motion sickness may lead to new treatments. The goal of this work was to determine if changes in cerebral blood flow precede the development of nausea in subjects susceptible to motion sickness. Methods: Cerebral flow velocity in the middle cerebral artery (transcranial Doppler), BP, and end-tical CO, were measured while subjects were rotated on a centrifuge (250degrees (.) s(-1)). Following 5 min of rotation, subjects were translated 51.5 cm off-center, creating a +1 Gx centripetal acceleration in the nasal-occipital plane. Results:There were 10 subjects who completed the protocol without symptoms while 5 developed nausea (4 while off-center and I while rotating on-center). Prior to nausea, subjects had significant increases in BP (+13 +/- 3 mmHg, p < 0.05) and cerebrovascular resistance (+46 +/- 17%, 1) < 0.05) and decreases in cerebral flow velocity both in the second(-13 +/- 4%) and last minute (-22 +/- 5%) before symptoms (p < 0.05). In comparison, subjects resistant to motion sickness demonstrated no change in BP or cerebrovascular resistance in the last minute of off center rotation and only a 7 +/- 2% decrease in cerebral flow velocity. All subjects had significant hypocapnia (-3.8 +/- 0.4 mmHg, p < 0.05); however, this hypocapnia could not fully explain the cerebral hypoperfusion associated with the development of nausea. Conculsions: These data indicate that reductions in cerebral blood flow precede the development of nausea. Further work is necessary to determine what role cerebral hypoperfusion plays in motion sickness and whether cerebral hypoperfusion can be used to predict the development of nausea in susceptible individuals. C1 Harvard Univ, Sch Med, Beth Israel Deaconess Med Ctr, Boston, MA 02115 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Legacy Hlth Syst, Neurotol Res, Portland, OR USA. Univ Space Res Assoc, Houston, TX USA. RP Serrador, JM (reprint author), Harvard Univ, Sch Med, Div Aging, BIDMC, Palmer 117,1 Deaconess Rd, Boston, MA 02215 USA. EM serrador@hms.harvard.edu RI Serrador, Jorge/A-9172-2009 FU NIDCD NIH HHS [R01 DC000205, R03 DC005545-01A1, R03 DC005547, R03DC005545, R03 DC005545] NR 16 TC 16 Z9 18 U1 0 U2 0 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 FEB PY 2005 VL 76 IS 2 BP 91 EP 96 PG 6 WC Public, Environmental & Occupational Health; Medicine, General & Internal; Sport Sciences SC Public, Environmental & Occupational Health; General & Internal Medicine; Sport Sciences GA 893FS UT WOS:000226705300002 PM 15742822 ER PT J AU Hansen, JE AF Hansen, JE TI A slippery slope: How much global warming constitutes "dangerous anthropogenic interference"? SO CLIMATIC CHANGE LA English DT Editorial Material ID SEA-LEVEL; ICE; CLIMATE; OCEAN; SIMULATIONS; MODEL; SOOT; SNOW C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP Hansen, JE (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM james.e.hansen@nasa.gov NR 24 TC 106 Z9 111 U1 3 U2 18 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD FEB PY 2005 VL 68 IS 3 BP 269 EP 279 DI 10.1007/s10584-005-4135-0 PG 11 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 904CN UT WOS:000227473800002 ER PT J AU Gatlin, K Boyd, JL Wang, Z Das, H Putcha, L AF Gatlin, K Boyd, JL Wang, Z Das, H Putcha, L TI Pharmacodynamics of promethazine in human subjects SO CLINICAL PHARMACOLOGY & THERAPEUTICS LA English DT Meeting Abstract CT 106th Annual Meeting of the American-Society-for-Clinical-Pharmacology-and-Therapeutics CY MAR 02-06, 2005 CL Orlando, FL SP Amer Soc Clin Pharmacol & Therapeut C1 Univ Space Res Assoc, Wyle Labs, Enterprise Advisory Serv, NASA,Johnson Space Ctr, Houston, TX 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 0009-9236 J9 CLIN PHARMACOL THER JI Clin. Pharmacol. Ther. PD FEB PY 2005 VL 77 IS 2 SU S BP P33 EP P33 DI 10.1016/j.clpt.2004.12.020 PG 1 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA 895GI UT WOS:000226848500125 ER PT J AU Seaborn, GT Moore, MK Balazs, GH AF Seaborn, GT Moore, MK Balazs, GH TI Depot fatty acid composition in immature green turtles (Chelonia mydas) residing at two near-shore foraging areas in the Hawaiian Islands SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY LA English DT Article DE algae; Chelonia mydas; diet; fatty acids; gas chromatography; lipid; marine turtle; seagrass ID TRANS-6-HEXADECENOIC ACID; DERMOCHELYS-CORIACEA; HABITAT USE; SEA; MARINE; FIBROPAPILLOMATOSIS; LIPIDS; FISH; INVERTEBRATES; SIGNATURES AB The lipid content and fatty acid composition of depot fat were determined for 58 immature Green turtle; (Chelonia mydas) residing at two near-shore foraging areas, Ahu-O-Laka, located in Kaneohe Bay on Oahu, and Kiholo Bay located on the island of Hawaii. Benthic flora at Kiholo was limited to a single algal species but included algae and seagrass at Ahu-O-Laka. Turtle straight carapace length ranged froth 38.6 to 59.2 cm, suggesting that the sample set included new recruits to up to 12-year residents. Fatty acid data were analyzed using principal components analysis (PCA). PC1 accounted for over 50% of the variance. Turtles were generally delineated alone PC1 by the length of time on benthic foraging grounds. with high (>0.75) negative loadings for the fatty acids 22:6n-3, 7M7H, t16:1n-10, 15:0, and 17:0 associated with relatively new recruits (suggesting a pelagic dietary source for these fatty acids) and high positive loadings for 12:0 and 14:0 associated with lone-teen residents. PC2 separated turtles primarily by capture location, with high positive loadings for 18:2n-6 and 18:3n-3 [the primary seagrass polyunsaturated fatty acids] associated with the Ahu-O-Laka turtles. Fatty acid profiles of turtles horn both locations differed substantially froth those of their benthic diets. suggesting considerable modification of dietary fatty acids and de novo biosynthesis. (C) 2004 Elsevier Inc. All rights reserved. C1 NOAA, Natl Ocean Serv, Natl Ctr Coastal Ocean Sci, Ctr Coastal Environm Hlth & Biomol Res, Charleston, SC 29412 USA. Natl Marine Fisheries Serv, Pacific Isl Fisheries Sci Ctr, Honolulu, HI 96822 USA. RP Seaborn, GT (reprint author), NOAA, Natl Ocean Serv, Natl Ctr Coastal Ocean Sci, Ctr Coastal Environm Hlth & Biomol Res, 219 Ft Johnson Rd, Charleston, SC 29412 USA. EM Gloria.Seaborn@noaa.gov NR 54 TC 11 Z9 12 U1 4 U2 10 PU ELSEVIER SCIENCE INC PI NEW YORK PA 360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USA SN 1096-4959 J9 COMP BIOCHEM PHYS B JI Comp. Biochem. Physiol. B-Biochem. Mol. Biol. PD FEB PY 2005 VL 140 IS 2 BP 183 EP 195 DI 10.1016/j.cbpc.2004.09.017 PG 13 WC Biochemistry & Molecular Biology; Zoology SC Biochemistry & Molecular Biology; Zoology GA 893OK UT WOS:000226728900002 PM 15649765 ER PT J AU Newton, RL Davidson, JL Lance, MJ AF Newton, RL Davidson, JL Lance, MJ TI Raman microscopic characterization of proton-irradiated polycrystalline diamond films SO DIAMOND AND RELATED MATERIALS LA English DT Article DE diamond film; microelectromechanical systems (MEMS); radiation-induced effects ID ION-IMPLANTATION; DAMAGE AB The microstructural effects of irradiating polycrystalline diamond films with protons was examined. The dosages ranged from 10(15) to 10(17) H+/cm(2). Scanning electron microscopy (SEM) and Raman microscopy were used to examine the ion implantation related changes as a function of depth. The results indicate that single crystal diamond and polycrystalline diamond exhibit similar behavior with respect to predicted vs. actual ion implant range, microstructural damage, and ion behavior both along the implant path and near the stopping location of the ions. Published by Elsevier B.V. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Vanderbilt Univ, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Newton, RL (reprint author), NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. EM robby.newton@nasa.gov RI Lance, Michael/I-8417-2016 OI Lance, Michael/0000-0001-5167-5452 NR 10 TC 4 Z9 4 U1 0 U2 3 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 FEB PY 2005 VL 14 IS 2 BP 173 EP 178 DI 10.1016/j.diamond.2004.09.008 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA 899UK UT WOS:000227170600006 ER PT J AU Shebalin, JV AF Shebalin, JV TI Theory and simulation of real and ideal magnetohydrodynamic turbulence SO DISCRETE AND CONTINUOUS DYNAMICAL SYSTEMS-SERIES B LA English DT Article; Proceedings Paper CT Minisymposium on Recent Advances in Vortex Dynamics held at the SIAM 2003 Dynamical Systems Meeting CY 2003 CL Snowbird, UT SP Int Soc Magnet Resonance Med DE homogeneous turbulence; magnetohydrodynamics; broken symmetry; coherent structure ID MEAN MAGNETIC-FIELD; HOMOGENEOUS TURBULENCE; ABSOLUTE EQUILIBRIUM; ISOTROPIC TURBULENCE; BROKEN ERGODICITY AB Incompressible, homogeneous magnetohydrodynamic (MHD) turbulence consists of fluctuating vorticity and magnetic fields, which are represented in terms of their Fourier coefficients. Here, a set of five Fourier spectral transform method numerical simulations of two-dimensional (2-D) MHD turbulence on a 512(2) grid is described. Each simulation is a numerically realized dynamical system consisting of Fourier modes associated with wave vectors k, with integer components, such that k = \k\ less than or equal to k(max). The simulation set consists of one ideal (non-dissipative) case and four real (dissipative) cases. All five runs had equivalent initial conditions. The dimensions of the dynamical systems associated with these cases are the numbers of independent real and imaginary parts of the Fourier modes. The ideal simulation has a dimension of 366104, while each real simulation has a dimension of 411712. The real runs vary in magnetic Prandtl number P-M, with P-M is an element of {0.1, 0.25, 1, 4}. In the results presented here, all runs have been taken to a simulation time of t = 25. Although ideal and real Fourier spectra are quite different at high k, they are similar at low values of k. Their low k behavior indicates the existence of broken symmetry and coherent structure in real MHD turbulence, similar to what exists in ideal MHD turbulence. The value of P-M strongly affects the ratio of kinetic to magnetic energy and energy dissipation (which is mostly ohmic). The relevance of these results to 3-D Navier-Stokes and MHD turbulence is discussed. C1 NASA, Lyndon B Johnson Space Ctr, Adv Space Prop Lab, Houston, TX 77058 USA. RP Shebalin, JV (reprint author), NASA, Lyndon B Johnson Space Ctr, Adv Space Prop Lab, Houston, TX 77058 USA. EM j.shebalin@jsc.nasa.gov NR 42 TC 6 Z9 6 U1 1 U2 1 PU AMER INST MATHEMATICAL SCIENCES PI SPRINGFIELD PA PO BOX 2604, SPRINGFIELD, MO 65801-2604 USA SN 1531-3492 J9 DISCRETE CONT DYN-B JI Discrete Contin. Dyn. Syst.-Ser. B PD FEB PY 2005 VL 5 IS 1 BP 153 EP 174 PG 22 WC Mathematics, Applied SC Mathematics GA 893TI UT WOS:000226741800011 ER PT J AU Williams, JW Seabloom, EW Slayback, D Stoms, DM Viers, JH AF Williams, JW Seabloom, EW Slayback, D Stoms, DM Viers, JH TI Anthropogenic impacts upon plant species richness and net primary productivity in California SO ECOLOGY LETTERS LA English DT Article DE California; human impacts; land cover change; net primary productivity; species richness; structural equation models ID UNITED-STATES; LATITUDINAL GRADIENTS; BIOLOGICAL INVASIONS; DATA SET; DIVERSITY; PATTERNS; CLIMATE; ENERGY; SCALE; TERRESTRIAL AB We assess the importance of anthropogenic land-use, altered productivity, and species invasions for observed productivity-richness relationships in California. To this end, we model net primary productivity (NPP) c. 1750 AD and at present (1982-1999) and map native and exotic vascular plant richness for 230 subecoregions. NPP has increased up to 105% in semi-arid areas and decreased up to 48% in coastal urbanized areas. Exotic invasions have increased local species diversity up to 15%. Human activities have reinforced historical gradients in species richness but reduced the spatial heterogeneity of NPP. Structural equation modelling suggests that, prior to European settlement, NPP and richness were primarily controlled by precipitation and other abiotic variables, with NPP mediating richness. Abiotic variables remain the strongest predictors of present NPP and richness, but intermodel comparisons indicate a significant anthropogenic impact upon statewide distributions of NPP and richness. Exotic and native species each positively correlate to NPP after controlling for other variables, which may help explain recent reports of positively associated native and exotic richness. C1 Natl Ctr Ecol Anal & Synth, Santa Barbara, CA 93101 USA. Univ Wisconsin, Dept Geog, Madison, WI 53706 USA. Oregon State Univ, Dept Zool, Corvallis, OR 97331 USA. NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Biospher Sci Branch, Greenbelt, MD 20771 USA. Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. Univ Calif Davis, Dept Environm Sci & Policy, Informat Ctr Environm, Davis, CA 95616 USA. Univ Calif Davis, John Muir Inst Environm, Davis, CA 95616 USA. RP Williams, JW (reprint author), Natl Ctr Ecol Anal & Synth, 735 State St,Suite 300, Santa Barbara, CA 93101 USA. EM jww@geography.wisc.edu RI Slayback, Daniel/E-7465-2011; OI Seabloom, Eric/0000-0001-6780-9259; /0000-0001-7957-7942 NR 66 TC 39 Z9 40 U1 3 U2 36 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 1461-023X J9 ECOL LETT JI Ecol. Lett. PD FEB PY 2005 VL 8 IS 2 BP 127 EP 137 DI 10.1111/j.1461-0248.2004.00706.x PG 11 WC Ecology SC Environmental Sciences & Ecology GA 890DF UT WOS:000226491200001 ER PT J AU Dubovikov, MS Canuto, VM AF Dubovikov, MS Canuto, VM TI Dynamic model of mesoscale eddies. Eddy parameterization for coarse resolution ocean circulation models SO GEOPHYSICAL AND ASTROPHYSICAL FLUID DYNAMICS LA English DT Article DE density and momentum large scale equations; isopycnal and level coordinates; bolus and eddy-induced velocity; residual density flux; Reynolds stress; vorticity flux ID RESIDUAL-MEAN VELOCITY; GENERAL-CIRCULATION; TRACER TRANSPORTS; VERTICAL SHEAR; EQUATIONS AB In the framework of the eddy dynamic model developed in two previous papers (Dubovikov, M.S., Dynamical model of mesoscale eddies, Geophys. Astophys. Fluid Dyn., 2003, 97, 311-358; Canuto, V.M. and Dubovikov, M.S., Modeling mesoscale eddies, Ocean Modelling, 2004, 8, 1-30 reterred as I-II), we compute the contribution of unresolved mesoscale eddies to the large-scale dynamic equations of the ocean. In isopycnal coordinates, in addition to the bolus velocity discussed in I-II, the mesoscale contribution to the large scale momentum equation is derived. Its form is quite different from the traditional down-gradient parameterization. The model solutions in isopycnal coordinates are transformed to level coordinates to parameterize the eddy contributions to the corresponding large scale density and momentum equations. In the former, the contributions due to the eddy induced velocity and to the residual density flux across mean isopycnals (so called Sigma-term) are derived, both contributions being shown to be of the same order. As for the large scale momentum equation, as well as in isopycnal coordinates, the eddy contribution has a form which is quite different from the down-gradient expression. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Columbia Univ, Ctr Climate Syst Res, New York, NY 10025 USA. Columbia Univ, Dept Appl Phys & Math, New York, NY 10027 USA. RP Canuto, VM (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. EM vcanuto@giss.nasa.gov NR 27 TC 5 Z9 5 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND SN 0309-1929 J9 GEOPHYS ASTRO FLUID JI Geophys. Astrophys. Fluid Dyn. PD FEB PY 2005 VL 99 IS 1 BP 19 EP 47 DI 10.1080/03091920412331336406 PG 29 WC Astronomy & Astrophysics; Geochemistry & Geophysics; Mechanics SC Astronomy & Astrophysics; Geochemistry & Geophysics; Mechanics GA 905YO UT WOS:000227607900002 ER PT J AU Killen, RM Bida, TA Morgan, TH AF Killen, RM Bida, TA Morgan, TH TI The calcium exosphere of Mercury SO ICARUS LA English DT Article DE mercury; atmosphere; composition ID ATMOSPHERE; IMPACT; ENERGY; SODIUM; DISTRIBUTIONS; VAPORIZATION; LUMINESCENCE; MARINER-10; DISCOVERY; POTASSIUM AB A tenuous calcium atmosphere at Mercury, principally seen in the polar regions, was first observed in July, 1998, using the High Resolution Echelle Spectrograph (HIRES) at the W.M. Keck I telescope (Bida et al., Nature 404, 159, 2000). We report four years of observations of the calcium exosphere of Mercury, confirming the initial findings of a very tenuous atmosphere. These observations show a persistent but spatially variable blue shift, indicating an excess velocity toward the observer of up to 3 km s(-1), with an average excess velocity of 2.2 km s(-1) above the south pole. In addition, the line profiles reveal a hot corona at the equivalent of 12,000-20,000 K in a thermalized atmosphere, indicating a large range of motion with respect to the observer. The calcium is not confined to the polar-regions: rare and low Ca abundance is seen in the equatorial regions. Strong emission was seen anti-sunward on 3 May 2002. Apparent weak emission on the sunward hemisphere may be due to scattered light from the surface, or may indicate a high latitude source. We show that the likely source of the calcium is either impact vaporization in the form of CaO and clusters, which are subsequently photo-dissociated, or ion-sputtering of atoms, molecules and ions. The column abundance is somewhat, but not strongly, correlated with solar activity. We predict a very hot (probably escaping) oxygen component to the hermean exosphere. (c) 2004 Elsevier Inc. All rights reserved. C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Lowell Observ, Flagstaff, AZ 86001 USA. NASA Headquarters, Washington, DC 20546 USA. RP Univ Maryland, Dept Astron, College Pk, MD 20742 USA. EM rkillen@astro.umd.edu RI Morgan, Thomas/I-5943-2013 NR 47 TC 42 Z9 43 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 EI 1090-2643 J9 ICARUS JI Icarus PD FEB PY 2005 VL 173 IS 2 BP 300 EP 311 DI 10.1016/j.icarus.2004.08.022 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905UT UT WOS:000227596700002 ER PT J AU Milani, A Chesley, SR Sansaturio, ME Tommei, G Valsecchi, GB AF Milani, A Chesley, SR Sansaturio, ME Tommei, G Valsecchi, GB TI Nonlinear impact monitoring: line of variation searches for impactors SO ICARUS LA English DT Article DE celestial mechanics; asteroids, dynamics; impacts ID ASTEROID IDENTIFICATION PROBLEM; EARTH; ENCOUNTERS; PLANE AB When a new near Earth asteroid is discovered, it is important to know whether or not there is the possibility of an impact with the Earth in the near future. In this paper, we describe the technical approaches employed by the two operational second-generation asteroid impact monitoring systems, CLOMON2 and Sentry, paying particular attention to the similarities and differences between these independent systems. The detection and characterization of a potential impact requires the propagation of the orbital probability density function from the time of discovery to the time of hypothetical impact. Since the N-body problem is not integrable, this can be done only by sampling the orbital elements space with a finite number of Virtual Asteroids (VAs), the orbit of each one being propagated numerically. Our methods, illustrated in this paper, use the Line Of Variation (LOV), a unidimensional subspace, to perform this sampling. The primary goal is to detect Virtual Impactors (VIs), which are regions in the initial conditions space leading to dynamically distinct collision solutions; then a probability integral needs to be computed on the volume of the VI. An important issue is how to assure completeness of such a search down to some impact probability threshold. This problem cannot be efficiently solved just by computing more VAs, but requires a geometric description of the behavior of the LOV in order to identify the critical segments of this curve. We have studied these behaviors on the Target Plane (TP) through our analytical theory and the output of many numerical tests. Assuming that the geometry is the simplest compatible with the data available from the sampling, we obtain a classification which allows us to use iterative methods, appropriate for each case, to find the closest approach distance possible along the LOV. After an LOV minimum has been identified, it is possible to use a probability density linearized at this point. However, when the cross section of the Earth is not crossed by the LOV, there is no guarantee that nonlinearity would be negligible in the direction on the TP transversal to the LOV. We describe how to test for such nonlinearity, and thus reduce or eliminate the possibility of spurious Vis. In this way, the performance of our impact monitoring systems has been significantly increased in comparison to the earlier and simpler solitary system. These more advanced systems have identified and then eliminated (through additional observations) more than one hundred cases of asteroids with VIs in the years 2002-2003. (c) 2004 Elsevier Inc. All rights reserved. C1 Univ Pisa, Dipartimento Matemat, I-56127 Pisa, Italy. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Valladolid, ETS Ingn Ind, E-47011 Valladolid, Spain. IASF, INAF, I-00133 Rome, Italy. RP Univ Pisa, Dipartimento Matemat, Via Buonarroti 2, I-56127 Pisa, Italy. EM milani@din.unipi.it OI Tommei, Giacomo/0000-0002-9593-613X; Valsecchi, Giovanni/0000-0002-2915-1465 NR 20 TC 51 Z9 51 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 EI 1090-2643 J9 ICARUS JI Icarus PD FEB PY 2005 VL 173 IS 2 BP 362 EP 384 DI 10.1016/j.icarus.2004.09.002 PG 23 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905UT UT WOS:000227596700008 ER PT J AU Lim, LF McConnochie, TH Bell, JF Hayward, TL AF Lim, LF McConnochie, TH Bell, JF Hayward, TL TI Thermal infrared (8-13 mu m) spectra of 29 asteroids: the Cornell Mid-Infrared Asteroid Spectroscopy (MIDAS) Survey SO ICARUS LA English DT Article DE asteroids, surfaces; spectroscopy; infrared observations; asteroids, Ceres; asteroids, Vesta ID NEAR-EARTH ASTEROIDS; MAIN BELT ASTEROIDS; IRRADIANCE CALIBRATION; 10 HYGIEA; 13-MU-M SPECTRA; CERES; SHAPE; 433-EROS; IMAGES; POLE AB We report the results of the Cornell Mid-IR Asteroid Spectroscopy (MIDAS) Survey, a program of ground-based observations designed to characterize the 8-13 mu m spectral properties of a statistically significant sample of asteroids from a wide variety of visible to near-IR spectral classes. MIDAS is conducted at Palomar Observatory using the Spectrocam-10 (SC-10) spectrograph on the 200-in Hale telescope. We have measured the mid-infrared spectra of twenty-nine asteroids and have derived temperature estimates front our data that are largely consistent with the predictions of the standard thermal model. We have also generated relative emissivity spectra for the target asteroids. On only one asteroid, 1 Ceres, have we found emissivity features with spectral contrast greater than 5%. Our spectrum of 4 Vesta suggests emissivity variation at the 2-3% level. Published spectra of several of the small number of asteroids observed with ISO (six of which are also included in our survey), which appeared to exhibit Much stronger emissivity features, are difficult to reconcile with our measurements. Laboratory work on mineral and meteorite samples has shown that the contrast of mid-IR spectral features is greatly reduced at fine grain sizes. Moreover, the NEAR mission found that 433 Eros is covered by a relatively thick fine-grained regolith. If small bodies in general possess such regoliths, their mid-IR spectral features may be quite subtle. This may explain the evident absence of strong emissivity variation in the majority of the MIDAS spectra. (c) 2004 Elsevier Inc. All rights reserved. C1 Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. AURA, Gemini S Observ, La Serena, Chile. RP Lim, LF (reprint author), Cornell Univ, Dept Astron, Ithaca, NY 14853 USA. EM lucylim@astro.cornell.edu RI Lim, Lucy/C-9557-2012 OI Lim, Lucy/0000-0002-9696-9654 NR 65 TC 39 Z9 39 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 FEB PY 2005 VL 173 IS 2 BP 385 EP 408 DI 10.1016/j.icarus.2004.08.005 PG 24 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905UT UT WOS:000227596700009 ER PT J AU de Pater, I DeBoer, D Marley, M Freedman, R Young, R AF de Pater, I DeBoer, D Marley, M Freedman, R Young, R TI Retrieval of water in Jupiter's deep atmosphere using microwave spectra of its brightness temperature SO ICARUS LA English DT Article DE Jupiter; atmosphere; radio observations; radiative transfer ID PROBE MASS-SPECTROMETER; LABORATORY MEASUREMENTS; RADIO OBSERVATIONS; DWARF ATMOSPHERES; OUTER PLANETS; SOLAR-SYSTEM; GAS-MIXTURES; ABSORPTION; AMMONIA; STRATIFICATION AB Despite several spacecraft encounters and numerous groundbased investigations, we still do not know Much about Jupiter's deep atmosphere; in fact, the Galileo probe results were so different than anyone had anticipated, that we understand even less about this planet's atmosphere now than before the Galileo mission. We formulate four basic questions in Section 1.3, which, if solved, would help to better understand the chemistry and dynamics in Jupiter's atmosphere. We believe that three out of the four questions (explanation of NH3 altitude profile, characterization of hot spots, altitude below which the atmosphere is uniformly mixed) may be solved from passive sounding of Jupiter's deep (similar to tens of bars) atmosphere via a radio telescope orbiting the planet. Question nr. 4 (the water abundance in Jupiter's deep atmosphere) has been singled out by the Solar System Exploration Decadal Survey as a key question, since the water abundance in Jupiter's deep atmosphere is tied in with planet formation models. In this paper we investigate the sensitivity of microwave retrievals to the composition Of Jupiter's deep atmosphere, in particular the water abundance. Based upon present uncertainties in the ammonia abundance and other known and unknown absorbers, including uncertainties in clouds (density and index of refraction), and uncertainties in the thermal structure and lineshape profiles, we conclude that the retrieval of water at depth from microwave spectra (disk-averaged and locally) will be highly uncertain. We show that, if the H2O lineshape profile would be accurately known (laboratory data are needed!), an atmosphere with a near-solar H2O abundance can likely be distinguished from one with ail abundance of 10-20 x solar O based upon the difference in their microwave spectra at wavelengths >= 50 cm. This Would be Sufficient to distinguish between some proposed scenarios by which Jupiter acquired its inventory of volatile elements heavier than helium. If, in addition, limb-darkening measurements are obtained (again, the H2O lineshape profile should be known), tighter constraints on the H2O abundance can be obtained (see also Janssen et al., 2004, this issue). (c) 2004 Elsevier Inc. All rights reserved. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. SETI Inst, Mountain View, CA 94043 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP de Pater, I (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. EM imke@astron.berkeley.edu RI Marley, Mark/I-4704-2013 NR 60 TC 19 Z9 19 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 FEB PY 2005 VL 173 IS 2 BP 425 EP 438 DI 10.1016/j.icarus.2004.06.019 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905UT UT WOS:000227596700012 ER PT J AU Janssen, MA Hofstadter, MD Gulkis, S Ingersoll, AP Allison, M Bolton, SJ Levin, SM Kamp, LW AF Janssen, MA Hofstadter, MD Gulkis, S Ingersoll, AP Allison, M Bolton, SJ Levin, SM Kamp, LW TI Microwave remote sensing of Jupiter's atmosphere from an orbiting spacecraft SO ICARUS LA English DT Article DE Jupiter, atmosphere; abundances, interior; radio observations; radiative transfer ID GALILEO PROBE DATA; GIANT PLANETS; RADIOMETER; ABUNDANCES; VOLATILES; ORIGIN; SOLAR AB Microwave remote sounding from a spacecraft flying by or in orbit around Jupiter offers new possibilities for retrieving important and presently Poorly understood properties of its atmosphere. In particular, we show that precise measurements of relative brightness temperature as a function of off-nadir emission angles, combined with absolute brightness temperature measurements, can allow us to determine the global abundances of water and ammonia and Study the dynamics and deep circulations of the atmosphere in the attitude range from the ammonia cloud region to depths greater than 30 bars in a manner which would not be achievable with ground-based telescopes. (c) 2004 Elsevier Inc. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Pasadena, CA 91125 USA. NASA, Goddard Inst Space Studies, New York, NY 10025 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM michael.a.janssen@jpl.nasa.gov NR 33 TC 26 Z9 26 U1 2 U2 10 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 EI 1090-2643 J9 ICARUS JI Icarus PD FEB PY 2005 VL 173 IS 2 BP 447 EP 453 DI 10.1016/j.icarus.2004.08.012 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905UT UT WOS:000227596700014 ER PT J AU Shematovich, VI Johnson, RE Cooper, JF Wong, MC AF Shematovich, VI Johnson, RE Cooper, JF Wong, MC TI Surface-bounded atmosphere of europa SO ICARUS LA English DT Article DE satellites, icy surfaces, sputtering; satellites, atmosphere; satellites, Europa ID ELECTRON-IMPACT IONIZATION; PARTIAL CROSS-SECTIONS; GALILEAN SATELLITES; OXYGEN ATMOSPHERE; ION-BOMBARDMENT; PLASMA TORUS; GAS TORUS; WATER ICE; H2O; O-2 AB A 1-D collisional Monte Carlo model of Europa's atmosphere is described in which the sublimation and sputtering sources of H2O molecules and their molecular fragments are accounted for as well as the radiolytically produced O-2. Dissociation and ionization of H2O and O-2 by magnetospheric electron, solar UV-photon and photo-electron impact, and collisional ejection from the atmosphere by the low-energy plasma are taken into account. Reactions with the surface are discussed, but only adsorption and atomic oxygen recombination are included in this model. The size of the surface-bounded oxygen atmosphere of Europa is primarily determined by a balance between atmospheric sources from irradiation of the satellite's icy surface by the high-energy magnetospheric charged particles and atmospheric losses from collisional ejection by the low-energy plasma, photo- and electron-impact dissociation, and ionization and pick-up from the surface-bounded atmosphere. A range of sources rates for O-2 to H2O are used with a larger oxygen-to-water ratio than suggested by laboratory measurements in order to account for differences in adsorption onto grains in the regolith. These calculations show that the atmospheric composition is determined by both the water and oxygen photochemistry in the near-surface region, escape of suprathermal oxygen and water into the jovian system, and the exchange of radiolytic water products with the porous regolith. For the electron impact ionization rates used, pick-up ionization is the dominant oxygen loss process, whereas photo-dissociation and atmospheric sputtering are the dominant sources of neutral oxygen for Europa's neutral torus. Including desorption and loss of water enhances the supply of oxygen species to the neutral torus, but hydrogen produced by radiolysis is the dominant source of neutrals for Europa's torus in these models. (c) 2004 Elsevier Inc. All rights reserved. C1 Russian Acad Sci, Inst Astron, Moscow 119017, Russia. Univ Virginia, Engn Phys Program, Charlottesville, VA 22903 USA. Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA. NASA, Goddard Space Flight Ctr, Raytheon Tech Serv Co LLC, SSDOO Project, Greenbelt, MD 20771 USA. Jet Prop Lab, Pasadena, CA 91109 USA. RP Russian Acad Sci, Inst Astron, 48 Pyatnitskaya St, Moscow 119017, Russia. EM shematov@inasan.rssi.ru RI Cooper, John/D-4709-2012; Shematovich, Valery/E-4670-2014 NR 71 TC 60 Z9 62 U1 0 U2 6 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 FEB PY 2005 VL 173 IS 2 BP 480 EP 498 DI 10.1016/j.icarus.2004.08.013 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905UT UT WOS:000227596700017 ER PT J AU Sada, PV Bjoraker, GL Jennings, DE Romani, PN McCabe, GH AF Sada, PV Bjoraker, GL Jennings, DE Romani, PN McCabe, GH TI Observations of C2H6 and C2H2 in the stratosphere of Saturn SO ICARUS LA English DT Article DE Saturn, Saturn; atmosphere, atmosphere; structure, atmospheres; composition, infrared observations ID ISO-SWS OBSERVATIONS; ATMOSPHERE; JUPITER; ETHANE; ACETYLENE; IUE; PH3 AB We have performed high-resolution spectral observations at mid-infrared wavelengths of C2H6 (12.16 mu m), and C2H2 (13.45 mu m) on Saturn. These emission features probe the stratosphere of the planet and provide information on the hydrocarbon photochemical processes taking place in that region of the atmosphere. The observations were performed using our cryogenic echelle spectrometer Celeste, in conjunction with the McMath-Pierce 1.5-m solar telescope in November and December 1994. We used Voyager IRIS CH4 observations (7.67 mu m) to derive a temperature profile on the saturnian atmosphere for the P <= similar to 1.6 mbar region of the stratosphere. This profile was then used in conjunction with height-dependent volume mixing ratios of each hydrocarbon to determine global abundances for ethane and acetylene. Our ground-based measurements indicate abundances of 6.7(-2.3)(+3.3) x 10(-6) for C2H6 (1.0 mbar pressure level), and 3.4(-1.1)(+1.5) x 10(-7) for C2H2 (1.6 mbar pressure level). We also derived new mixing ratios from the Voyager mid-latitude IRIS observations; 8.6 +/- 0.9 x 10(-6) for C2H6 (0.1-3.0 mbar pressure level), and 1.6 +/- 0.2 x 10(-7) for C2H2 (2.0 mbar pressure level). (c) 2004 Elsevier Inc. All rights reserved. C1 NASA, Goddard Space Flight Ctr, Planetary Syst Branch, Greenbelt, MD 20771 USA. RP Sada, PV (reprint author), Univ Monterrey, Dept Fis & Matemat, Av I Morones Prieto 4500 Pte, Garza Garcia 66238, NL, Mexico. EM psada@ix.netcom.com RI Romani, Paul/D-2729-2012; Bjoraker, Gordon/D-5032-2012; Jennings, Donald/D-7978-2012 NR 30 TC 24 Z9 24 U1 0 U2 1 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0019-1035 J9 ICARUS JI Icarus PD FEB PY 2005 VL 173 IS 2 BP 499 EP 507 DI 10.1016/j.icarus.2004.08.006 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905UT UT WOS:000227596700018 ER PT J AU McGhee, CA French, RG Dones, L Cuzzi, JN Salo, HJ Danos, R AF McGhee, CA French, RG Dones, L Cuzzi, JN Salo, HJ Danos, R TI HST observations of spokes in Saturn's B ring SO ICARUS LA English DT Article DE planetary rings, Saturn; radiative transfer ID PHASE CURVES; PARTICLES; CONSTRAINTS; PHOTOMETRY; SYSTEM; LIGHT AB As part of a long-term study of Saturn's rings, we have used the Hubble Space Telescope's (HST) Wide Field and Planetary Camera (WFPC2) to obtain several hundred high resolution images from 1996 to 2004, spanning the full range of ring tilt and solar phase angles accessible from the Earth. Using these multi wavelength observations and HST archival data, we have measured the photometric properties of spokes in the B ring, visible in a substantial number of images. We determined the spoke particle size distribution by fitting the wavelength-dependent extinction efficiency of a prominent, isolated spoke, using a Mie scattering model. Following Doyle and Grun (1990, Icarus 85, 168-190), we assumed that the spoke particles were sub-micron size spheres of pure water ice, with a Hansen-Hovenier size distribution (Hansen and Hovenier, 1974, J. Atmos. Sci. 31, 1137-1160). The WFPC2 wavelength coverage is broader than that of the Voyager data, resulting in tighter constraints on the nature of spoke particles. The effective particle size was r(eff) = 0.57 +/- 0.05 pm, and the size distribution was quite narrow with a variance of b = 0.09 +/- 0.03, very similar to the results of Doyle and Grun (1990, Icarus 85, 168-190), and consistent with predictions of plasma cloud models for spoke production from meteoritic impacts (Goertz and Morfill, 1983, Icarus 53, 219-229; Goertz, 1984, Adv. Space Res. 4, 137-141). In all, we identified 36 spokes or spoke complexes, predominantly on the morning (east) ansa. The photometric contrast of the spokes is strongly dependent on effective ring opening angle, B-eff. Spokes were clearly visible on the north face of the rings in 1994, just prior to the most recent ring plane crossing (RPX) epoch, and on the south face shortly after RPX. However, spokes were both less abundant and fainter as the rings opened up, and no spokes were detected after 18 October 1998 (B-eff = -15.43 degrees), when a single faint spoke was seen on the morning ansa. The high resolution and photometric quality of the WFPC2 images enabled LIS to set a detection limit of <= 1% in fractional brightness contrast for spokes for the post-1998 observations. We compare the observed trend of spoke contrast with Beff to radiative transfer calculations based on three models of the distribution of spoke material. In the first, the spoke "haze" is uniformly mixed with macroscopic B ring particles. No variation in spoke contrast is predicted for single-scattering, in this case, and only a modest decrease in contrast with B-eff is predicted when multiple scattering is taken into account. In the second model, the spoke dust occupies an extended layer that is thicker than the B ring, which gives virtually identical results to a third case, when the haze layer lies exclusively above the ring. Multi pie-scattering Monte Carlo calculations for these two extended haze models match the trend of spoke contrast exceptionally well. We compute the predicted spoke contrast for a wide variety of viewing geometries, including forward- and backscattering. Based on these results, spokes should be easily detectable during the Cassini mission when the rings are viewed at relatively small (vertical bar B vertical bar <= 10 degrees) ring opening angles. (c) 2004 Elsevier Inc. All rights reserved. C1 Wellesley Coll, Dept Astron, Wellesley, MA 02481 USA. SW Res Inst, Boulder, CO 80302 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Univ Oulu, Astron Div, Oulu, Finland. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Wellesley Coll, Dept Astron, Wellesley, MA 02481 USA. EM cmcghee@wellesley.edu NR 44 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 EI 1090-2643 J9 ICARUS JI Icarus PD FEB PY 2005 VL 173 IS 2 BP 508 EP 521 DI 10.1016/j.icarus.2004.09.001 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 905UT UT WOS:000227596700019 ER PT J AU Shieh, W Maleki, L AF Shieh, W Maleki, L TI Phase noise characterization by carrier suppression techniques in RF photonic systems SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE microwave; optical fiber applications; phase noise; phased array radar; photodetector AB We propose and demonstrate a novel approach to measure the phase noise in radio-frequency photonic systems by employing a suppressed carrier technique. With this technique, the flicker phase noise floor is reduced by 36 dB. To the best of our knowledge, this is the first time that the phase noise of a photodetector is measured, and found to be - 126 dBc/Hz at 1 Hz from the carrier at 8.4 GHz. C1 Univ Melbourne, Photon Res Lab, Australian Photon CRC, Melbourne, Vic 3010, Australia. Univ Melbourne, Dept Elect & Elect Engn, Ctr Ultra Broadband Informat Networks, Melbourne, Vic 3010, Australia. Jet Prop Lab, Quantum Sci & Technol Grp, Pasadena, CA 91109 USA. RP Shieh, W (reprint author), Univ Melbourne, Photon Res Lab, Australian Photon CRC, Melbourne, Vic 3010, Australia. EM w.shieh@ee.mu.oz.au OI Shieh, William/0000-0003-1777-5403 NR 8 TC 7 Z9 7 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD FEB PY 2005 VL 17 IS 2 BP 474 EP 476 DI 10.1109/LPT.2004.839781 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 889ZO UT WOS:000226481700071 ER PT J AU Jackson, B Scargle, JD Barnes, D Arabhi, S Alt, A Gioumousis, P Gwin, E Sangtrakulcharoen, P Tan, L Tsai, TT AF Jackson, B Scargle, JD Barnes, D Arabhi, S Alt, A Gioumousis, P Gwin, E Sangtrakulcharoen, P Tan, L Tsai, TT TI An algorithm for optimal partitioning of data on an interval SO IEEE SIGNAL PROCESSING LETTERS LA English DT Article DE Bayesian modeling; cluster analysis; density estimation; histograms; optimization; signal detection ID CHANGE POINT PROBLEMS; TIME-SERIES; SEGMENTATION PROCEDURE; TEXT SEGMENTATION; MODELS AB Many signal processing problems can be solved by maximizing the fitness of a segmented model over all possible partitions of the data interval. This letter describes a simple but powerful algorithm that searches the exponentially large space of partitions of N data points in time O(N-2). The algorithm is guaranteed to find the exact global optimum, automatically determines the model order (the number of segments), has a convenient realtime mode, can be extended to higher dimensional data spaces, and solves a surprising variety of problems in signal detection and characterization, density estimation, cluster analysis, and classification. C1 San Jose State Univ, Dept Math, San Jose, CA 95112 USA. NASA, Ames Res Ctr, Space Res Div, Moffett Field, CA 94035 USA. San Jose State Univ, Ctr Appl Math & Comp Sci, San Jose, CA 95112 USA. RP Jackson, B (reprint author), San Jose State Univ, Dept Math, San Jose, CA 95112 USA. EM Jeffrey.D.Scargle@nasa.gov NR 22 TC 70 Z9 70 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 1070-9908 J9 IEEE SIGNAL PROC LET JI IEEE Signal Process. Lett. PD FEB PY 2005 VL 12 IS 2 BP 105 EP 108 DI 10.1109/LSP.2001.838216 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA 890IA UT WOS:000226503700006 ER PT J AU Focardi, P Freni, A Maci, S Vecchi, G AF Focardi, P Freni, A Maci, S Vecchi, G TI Efficient analysis of arrays of rectangular corrugated horns: The synthetic aperture function approach SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Article DE array antennas; horns; mutual coupling ID DESIGN AB This paper presents a procedure to reduce the computational effort for the full-wave analysis of corrugated or stepped rectangular horns/cavities, open-ended on an infinite ground plane. This procedure, framed in the method of moments (MoM), is based on the construction of appropriate basis functions generated by solving the problem of one element in isolation. These functions are termed "synthetic aperture functions" (SAF); being numerical solutions of a physical problem, they have the adequate contents of high-order waveguide modes which allow the Proper storage of local reactive energy. They also include a good approximation of the correct edge behavior. The technique reveals a significant reduction of computational resources compared to an ordinary MoM solution, especially for a large number of radiating elements. C1 Univ Florence, Dept Elect & Telecommun, I-50139 Florence, Italy. CALTECH, Jet Prop Lab, Sub Millimeter Wave Superconduct Sensor Grp, Pasadena, CA 91109 USA. Univ Siena, Dept Informat Engn, I-53100 Siena, Italy. Politecn Torino, Dept Elect, CERCOM, I-10129 Turin, Italy. RP Focardi, P (reprint author), CALTECH, Jet Prop Lab, Sub Millimeter Wave Superconduct Sensor Grp, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Paolo.Focardi@jpl.nasa.gov; freni@unifi.it; macis@ing.unisi.it; vecchi@polito.it OI VECCHI, Giuseppe/0000-0003-0798-5431 NR 10 TC 8 Z9 8 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0018-926X J9 IEEE T ANTENN PROPAG JI IEEE Trans. Antennas Propag. PD FEB PY 2005 VL 53 IS 2 BP 601 EP 607 DI 10.1109/TAP.2004.841332 PG 7 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 896OT UT WOS:000226944100002 ER PT J AU Shin, J Akyurtlu, A Deshpande, M AF Shin, J Akyurtlu, A Deshpande, M TI Comments on "Design, fabrication, and testing of double negative metamaterials" SO IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION LA English DT Editorial Material C1 CNR, Washington, DC 20001 USA. Univ Massachusetts, Lowell, MA 01854 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Shin, J (reprint author), CNR, Washington, DC 20001 USA. EM jshin@ieee.org NR 5 TC 1 Z9 2 U1 0 U2 3 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 FEB PY 2005 VL 53 IS 2 BP 891 EP 891 DI 10.1109/TAP.2004.841266 PG 1 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 896OT UT WOS:000226944100041 ER PT J AU Simon, MK Annavajjala, R AF Simon, MK Annavajjala, R TI On the optimality of bit detection of certain digital modulations SO IEEE TRANSACTIONS ON COMMUNICATIONS LA English DT Article DE bit metric; error-probability analysis; Gray coding; log-likelihood ratio (LLR) ID M-ARY PSK; ERROR RATE; COMPUTATION AB In this paper, we study the optimality of bit detection for coherent M-ary phase-shift keying (PSK) and M-ary quadrature amplitude modulation (QAM), and noncoherent M-ary frequency-shift keying (FSK) signal sets. For M-PSK and signal constellations, we employ Gray mapping, consider 8-PSK and 16-QAM signal sets as representative of the general results, and derive the log-likelihood ratio (LLR) for each bit forming the symbol. Using the LLRs, we derive the average bit-error probability (BEP) for the individual bits, and show that the decision regions and the corresponding average BEP for the case of M-PSK coincide with those obtained with the optimal symbol-based detector, whereas, in general, this is not the case for both M-QAM and M-FSK. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Calif San Diego, Dept Elect & Comp Engn, La Jolla, CA 92093 USA. RP Simon, MK (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM marvin.k.simon@jpl.nasa.gov; ramesh@cwc.ucsd.edu NR 10 TC 25 Z9 27 U1 0 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 FEB PY 2005 VL 53 IS 2 BP 299 EP 307 DI 10.1109/TCOMM.2004.841959 PG 9 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 903DL UT WOS:000227405600014 ER PT J AU Khan, ZA Bunting, CF Deshpande, MD AF Khan, ZA Bunting, CF Deshpande, MD TI Shielding effectiveness of metallic enclosures at oblique and arbitrary polarizations SO IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY LA English DT Article DE shielding; statistical methods ID POLYNOMIAL APPROXIMATIONS; SMALL APERTURES; POLARIZABILITIES; EXCITATION; FREQUENCY; CAVITIES; WAVE; FDTD AB Shielding effectiveness of metallic enclosures with apertures when illuminated by an oblique incidence arbitrary polarized plane wave has been studied by using an efficient hybrid modal/moment technique. Shielding effectiveness of rectangular enclosures with one, two, and four apertures at multiple points inside the enclosures for various frequencies has been calculated when the illuminating source flies by the front of the enclosure. The work shows that the shielding effectiveness is seriously affected by frequency, angle of incidence and polarization of the illuminating field; the number and orientation of apertures; and the location inside the cavity. It has been shown that the usual assumption about the normal incidence being the worst-case scenario for shielding effectiveness values may not be valid when there is more than one aperture in the cavity. The paper emphasizes the need for the statistical investigation of shielding effectiveness problem of metallic enclosures with apertures. C1 Ohio State Univ, Sch Elect & Comp Engn, Columbus, OH 43210 USA. Oklahoma State Univ, Sch Elect & Comp Engn, Oklahoma City, OK 73107 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Khan, ZA (reprint author), Ohio State Univ, Sch Elect & Comp Engn, Columbus, OH 43210 USA. EM reverb@okstate.edu RI Bunting, Charles/B-9762-2013 OI Bunting, Charles/0000-0001-9167-4235 NR 36 TC 30 Z9 30 U1 1 U2 2 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9375 J9 IEEE T ELECTROMAGN C JI IEEE Trans. Electromagn. Compat. PD FEB PY 2005 VL 47 IS 1 BP 112 EP 122 DI 10.1109/TEMC.2004.842117 PG 11 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA 899HK UT WOS:000227135300014 ER PT J AU Xiong, XX Che, NZ Barnes, W AF Xiong, XX Che, NZ Barnes, W TI Terra MODIS on-orbit spatial characterization and performance SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article DE calibration; instrument; remote sensing; spatial alignment ID BANDS CALIBRATION ALGORITHM; REFLECTIVE SOLAR BANDS; ASSEMBLY SRCA AB The Moderate Resolution Imaging Spectroradiometer (MODIS) Proto-Flight Model, onboard the National Aeronautics and Space Administration's Earth Observing System Terra spacecraft, has been in operation for over four years. It has 36 spectral bands and a total of 490 detectors located on four focal plane assemblies (FPAs). MODIS makes observations at three spatial resolutions (nadir): 0.25 km (bands 1-2), 0.5 km (bands 3-7), and 1 km (bands 8-36). The instrument's spatial characterization was measured prelaunch using an integration and alignment collimator. Parameters measured included the detectors' instantaneous field-of-view (IFOV), hand-to-hand registration (BBR), and line spread function in both the along-scan and along-track directions. On-orbit, the spatial characterization is periodically measured using the onboard spectro-radiometric calibration assembly (SRCA). This paper describes the SRCA BBR algorithms. characterization methodologies, and on-orbit results. A Fourier approach used to calculate the along-track BBR is also described. This approach enhances the algorithm's robustness in comparison with the conventional centroid approach. On-orbit results show that the Terra MODIS focal planes shifted slightly during launch and initial on-orbit operation. Since then they have been very stable. The BBR is within 0.16 km (nadir IFOV) in the along-scan direction and 0.23 km (nadir IFOV) in the along-track direction among all hands. The small but noticeable periodic variation of the on-orbit BBR can be attributed to the annual cycling of instrument temperature due to sun-earth distance variation. The visible FPA position has the largest temperature dependence among all FPAs, 17 m/K along-scan and 0.6 m/K along-track. C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Sci Syst & Applicat Inc, Lanham, MD 20706 USA. Univ Maryland Baltimore Cty, Baltimore, MD 21250 USA. RP Xiong, XX (reprint author), NASA, Goddard Space Flight Ctr, Code 661, Greenbelt, MD 20771 USA. EM xiaoxiong.xiong.1@gsfc.nasa.gov; nianzeng_che@ssaihq.com; wbarnes@neptune.gsfc.nasa.gov NR 15 TC 95 Z9 96 U1 2 U2 8 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 FEB PY 2005 VL 43 IS 2 BP 355 EP 365 DI 10.1109/TGRS.2004.840643 PG 11 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA 890HK UT WOS:000226502100017 ER PT J AU Cameron, CB Rodriguez, RN Padgett, N Waluschka, E Kizhner, S AF Cameron, CB Rodriguez, RN Padgett, N Waluschka, E Kizhner, S TI Optical ray tracing using parallel processors SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE digital signal processor (DSP); optical ray tracing; optics; parallel processing; reconfigurable computer (RC); reconfigurable computing AB One of the instruments on the sun-synchronous Terra (EOS AM) and Aqua (EOS PM) spacecraft, the Moderate Resolution Spectroradiometer (MODIS), obtains calibration data once during every orbit. Observations of the sun permit corrections to observations of the earth during the ensuing orbit Although the instrument was designed to receive uniform sunlight over the entire surface of its detector, the sunlight was in fact not uniform. While this did not adversely affect the calibration, it nonetheless implied a lack of understanding of how the optical system really functioned. To learn what was wrong, NASA used an optical ray-tracing program on a DEC Alpha computer. The results correlated well with the observations made by the instrument itself, but it took nearly two weeks to complete the computer simulation, a discouragingly long time. This paper describes the algorithm and its implementation in a system with multiple digital signal processor (DSP) chips operating in parallel. Timing data show a highly linear relationship between the number of DSPs present and the speed of the computation. Administrative overhead is negligible compared to the time taken to compute ray trajectories. This implies that many more than just four DSPs could be harnessed before administrative overhead would begin to be significant. C1 USN Acad, Annapolis, MD 21402 USA. Georgia Inst Technol, St Paul, MN 55112 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20768 USA. RP Cameron, CB (reprint author), USN Acad, Annapolis, MD 21402 USA. NR 11 TC 4 Z9 4 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD FEB PY 2005 VL 54 IS 1 BP 87 EP 97 DI 10.1109/TIM.2004.838131 PG 11 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 887ZA UT WOS:000226342800012 ER PT J AU Schwartz, ZD Downey, AN Alterovitz, SA Ponchak, GE AF Schwartz, ZD Downey, AN Alterovitz, SA Ponchak, GE TI High-temperature RF probe station for device characterization through 500 degrees C and 50 GHz SO IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT LA English DT Article DE coplanar waveguide; high temperature; microwave measurements; radio-frequency (RF) probing; SiC AB A high-temperature measurement system capable of performing on-wafer microwave testing of semiconductor devices has been developed. This high-temperature probe station can characterize active and passive devices and circuits at temperatures ranging from room temperature to above 500degreesC. The heating system uses a ceramic heater mounted on an insulating block of NASA shuttle tile. The temperature is adjusted by a graphical computer interface and is controlled by the software-based feedback loop. The system is used with a vector network analyzer to measure scattering parameters over a frequency range from 1 to 50 GHz. The microwave probes, cables, and inspection microscope are all shielded to protect from heat damage. The high-temperature probe station has been successfully used to characterize gold transmission lines on silicon carbide at temperatures up to 540degreesC. C1 NASA, Analex Corp, Glenn Res Ctr, Cleveland, OH 44135 USA. RP Schwartz, ZD (reprint author), NASA, Analex Corp, Glenn Res Ctr, Cleveland, OH 44135 USA. EM zachary.d.schwartz@grc.nasa.gov NR 9 TC 20 Z9 20 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855 USA SN 0018-9456 J9 IEEE T INSTRUM MEAS JI IEEE Trans. Instrum. Meas. PD FEB PY 2005 VL 54 IS 1 BP 369 EP 376 DI 10.1109/TIM.2004.838137 PG 8 WC Engineering, Electrical & Electronic; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA 887ZA UT WOS:000226342800050 ER PT J AU Paidi, VK Griffith, Z Wei, Y Dahlstrom, M Urteaga, M Parthasarathy, N Seo, M Samoska, L Fung, A Rodwell, MJW AF Paidi, VK Griffith, Z Wei, Y Dahlstrom, M Urteaga, M Parthasarathy, N Seo, M Samoska, L Fung, A Rodwell, MJW TI G-band (140-220 GHz) and W-Band (75-110 GHz) InP DHBT medium power amplifiers SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article; Proceedings Paper CT 15th International Conference on Microwaves Radar and Wireless Communications CY MAY 17-19, 2004 CL Warsaw, POLAND DE InP heterojunction bipolar transistor; millimeterwave amplifier; monolithic microwave integrated circuit (MMIC) amplifiers AB We ieport common-base medium power amplifiers designed for G-band (140-220 GHz) and W-band(757110 GHz) in InP mesa double HBT technology. The common-base topology is preferred over common-emitter and common-collector topologies due to its superior high-frequency maximum stable gain (MSG). Base feed inductance and collector emitter overlap capacitance, however, reduce the common-base MSG. A single-sided collector contact reduces C-ce and, hence, improves the MSG. A single-stage common-base tuned amplifier exhibited 7-dB small-signal gain at 176 GHz. This amplifier demonstrated 8.7-dBm output power with 5-dB associated power gain at 172 GHz. A two-stage common-base amplifier exhibited 8.1-dBm output power with 6.3-dB associated power gain at 176 GHz and demonstrated 9.1-dBm saturated output power. Another two-stage common-base amplifier exhibited 11.6-dBm output power with an associated power gain of 4.5 dB at 148 GHz. In the W-band, different designs of single-stage common-base power amplifiers demonstrated saturated output power of 15.1 dBm at 84 GHz and 13.7 dBm at 93 GHz. C1 Univ Calif Santa Barbara, Dept Elect & Comp Engn, Santa Barbara, CA 93106 USA. Rockwell Sci Corp, Thousand Oaks, CA 91360 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Paidi, VK (reprint author), Univ Calif Santa Barbara, Dept Elect & Comp Engn, Santa Barbara, CA 93106 USA. EM paidi@ece.ucsb.edu NR 6 TC 36 Z9 40 U1 1 U2 3 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 FEB PY 2005 VL 53 IS 2 BP 598 EP 605 DI 10.1109/TMTT.2004.840662 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA 896BQ UT WOS:000226910000023 ER PT J AU Ponchak, GE Papapolymerou, J Tentzeris, MM AF Ponchak, GE Papapolymerou, J Tentzeris, MM TI Excitation of coupled slotline mode in finite-ground CPW with unequal ground-plane widths SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE coplanar waveguide (CPW); coupling; transmission lines ID FREQUENCY DISTRIBUTION NETWORKS; WAVE-GUIDE DISCONTINUITIES; ELEMENTS AB The coupling between the desired coplanar-waveguide (CPW) mode and the unwanted coupled slotline mode is presented for finite-ground CPWs with unequal ground-plane widths. Measurements, quasi-static conformal mapping, and finite-difference time-domain analysis are performed to determine the dependence of the slotline-mode excitation on the physical dimensions of the finite-ground coplanar line and on the frequency range of operation. It is shown that the ratio of the slotline mode to the CPW mode can be as high as 10 dB. Air-bridges are shown to reduce the slotline mode by 15 dB immediately after the air-bridge, but the slotline mode fully reestablishes itself within 2000 mum of the air-bridge. Furthermore, these results are independent of frequency. C1 NASA, Glenn Res Ctr, Electron Device Technol Branch, Cleveland, OH 44135 USA. Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. RP Ponchak, GE (reprint author), NASA, Glenn Res Ctr, Electron Device Technol Branch, Cleveland, OH 44135 USA. NR 15 TC 26 Z9 26 U1 0 U2 5 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 FEB PY 2005 VL 53 IS 2 BP 713 EP 717 DI 10.1109/TMTT.2004.840571 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA 896BQ UT WOS:000226910000036 ER PT J AU Carterson, AJ Bentrup, KHZ Ott, CM Clarke, MS Pierson, DL Vanderburg, CR Buchanan, KL Nickerson, CA Schurr, MJ AF Carterson, AJ Bentrup, KHZ Ott, CM Clarke, MS Pierson, DL Vanderburg, CR Buchanan, KL Nickerson, CA Schurr, MJ TI A549 lung epithelial cells grown as three-dimensional aggregates: Alternative tissue culture model for Pseudomonas aeruginosa pathogenesis SO INFECTION AND IMMUNITY LA English DT Article ID SIMULATED MICROGRAVITY; CYSTIC-FIBROSIS; INFECTION; RECEPTORS; ADHERENCE; ADHESION; INVASION; MUCIN; LINES; CYTOTOXICITY AB A three-dimensional (3-D) lung aggregate model was developed from A549 human lung epithelial cells by, using a rotating-wall vessel bioreactor to study the interactions between Pseudomonas aeruginosa and lung epithelial cells. The suitability of the 3-D aggregates as an infection model was examined by immunohistochemistry, adherence and invasion assays, scanning electron microscopy, and cytokine and mucoglycoprotein production. Immunohistochemical characterization of the 3-D A549 aggregates showed increased expression of epithelial cell-specific markers and decreased expression of cancer-specific markers compared to their monolayer counterparts. Immunohistochemistry of junctional markers on A549 3-D cells revealed that these cells formed tight junctions and polarity, in contrast to the cells grown as monolayers. Additionally, the 3-D aggregates stained positively for the production of mucoglycoprotein while the monolayers showed no indication of staining. Moreover, mucin-specific antibodies to MUC1 and MUC5A bound with greater affinity to 3-D aggregates than to the monolayers. P. aeruginosa attached to and penetrated A,549 monolayers significantly more than the same cells grown as 3-D aggregates. Scanning electron microscopy or A549 cells grown as monolayers and 3-D aggregates infected with P. aeruginosa showed that monolayers detached from the surface of the culture plate postinfection, in contrast to the 3-D aggregates, which remained attached to the micro-carrier beads. In response to infection, proinflammatory cytokine levels were elevated for the 3-D A549 aggregates compared to monolayer controls. These findings suggest that A549 lung cells grown as 3-D aggregates may represent a more physiologically relevant model to examine the interactions between P. aeruginosa and the lung epithelium during infection. C1 Tulane Univ, Ctr Hlth Sci, Dept Microbiol & Immunol, Program Mol Pathogenesis & Immun,Tulane Ctr Excel, New Orleans, LA 70112 USA. Louisiana Ctr Lung Biol & Immunotherapy, New Orleans, LA USA. EASI, Wyle Labs, Houston, TX USA. Univ Space Res Assoc, Div Space Life Sci, Houston, TX USA. NASA, Johnson Space Ctr, Habitabil & Environm Factors Off, Houston, TX USA. Massachusetts Gen Hosp, Boston, MA 02114 USA. RP Schurr, MJ (reprint author), Tulane Univ, Ctr Hlth Sci, Dept Microbiol & Immunol, Program Mol Pathogenesis & Immun,Tulane Ctr Excel, 1430 Tulane Ave, New Orleans, LA 70112 USA. EM mschurr@tulane.edu FU NIAID NIH HHS [R01 AI050812-02] NR 47 TC 94 Z9 95 U1 1 U2 19 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1752 N ST NW, WASHINGTON, DC 20036-2904 USA SN 0019-9567 J9 INFECT IMMUN JI Infect. Immun. PD FEB PY 2005 VL 73 IS 2 BP 1129 EP 1140 DI 10.1128/IAI.73.2.1129-1140.2005 PG 12 WC Immunology; Infectious Diseases SC Immunology; Infectious Diseases GA 893PM UT WOS:000226731700053 PM 15664956 ER PT J AU Ayres, T Li, L Trachtman, D Young, D AF Ayres, T Li, L Trachtman, D Young, D TI Passenger-side rear-view mirrors: driver behavior and safety SO INTERNATIONAL JOURNAL OF INDUSTRIAL ERGONOMICS LA English DT Article; Proceedings Paper CT 3rd International Cyberspace Conference on Ergonomics (CybEeg 2002) CY 2002 CL ELECTR NETWORK DE driver behavior; mirror; accident data; traffic safety ID VISUAL SEARCH AB Passenger-side rear-view mirrors (PRMs) have been standard equipment on motor vehicles sold in the US for many years, although they are not required by the federal motor vehicle safety standards. Numerous studies documented both the apparent need for PRMs (to overcome visual obstructions) and their apparent value (by increasing visual access to the passenger-side rear). In addition, surveys of drivers have found a general appreciation of the importance of sampling visual information from the rear. Very little can be found, however, regarding the actual safety benefit of PRMs. A review of the research literature and several initial studies (driver observation and accident-data analysis), suggest that PRMs may not be associated with any substantial accident prevention, perhaps because they are not consistently used. Implications and research directions will be discussed. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Exponent, Los Angeles, CA 90066 USA. RP Ayres, T (reprint author), Box 60591, Palo Alto, CA 94306 USA. NR 20 TC 7 Z9 8 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-8141 J9 INT J IND ERGONOM JI Int. J. Ind. Ergon. PD FEB PY 2005 VL 35 IS 2 BP 157 EP 162 DI 10.1016/j.ergon.2004.05.009 PG 6 WC Engineering, Industrial; Ergonomics SC Engineering GA 886UI UT WOS:000226257800006 ER PT J AU Snell, EH van der Woerd, MJ Miller, MD Deacon, AM AF Snell, EH van der Woerd, MJ Miller, MD Deacon, AM TI Finding a cold needle in a warm haystack: infrared imaging applied to locating cryocooled crystals in loops SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID STRUCTURAL GENOMICS; MACROMOLECULAR CRYSTALLOGRAPHY; PROTEIN CRYSTALLOGRAPHY; DRUG DISCOVERY; BEAMLINE; SYSTEM; CRYOCRYSTALLOGRAPHY; FIP AB The use of infrared imaging to locate crystals mounted in cryoloops and cryopreserved in a nitrogen gas stream at 100 K is demonstrated. In the home laboratory, crystals are clearly seen in the infrared images with light transmitting through the sample while irradiating the crystal from behind, and with illumination from a direction perpendicular to the direction of view. The crystals transmit and reflect infrared radiation at different levels to the surrounding mother liquor and loop. Because of differences in contrast between crystals and their surrounding mother liquor, it is possible to identify the crystal position. At the synchrotron, with robotically mounted crystals, the small depth of field of the lens required the recording of multiple images at different focal points. Image processing techniques were then used to construct a clear image of the crystal. The resulting infrared images and intensity profiles show that infrared imaging can be a powerful complement to visual imaging in locating crystals in cryocooled loops. C1 NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Stanford Univ, JCSG, SSRL, Menlo Pk, CA 94025 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. RP Snell, EH (reprint author), NASA, George C Marshall Space Flight Ctr, Code SD46, Huntsville, AL 35812 USA. EM eddie.snell@msfc.nasa.gov NR 23 TC 9 Z9 9 U1 0 U2 0 PU BLACKWELL MUNKSGAARD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD FEB PY 2005 VL 38 BP 69 EP 77 DI 10.1107/S0021889804027566 PN 1 PG 9 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 889AA UT WOS:000226414500006 ER PT J AU Mace, GG Zhang, YY Platnick, S King, MD Minnis, P Yang, P AF Mace, GG Zhang, YY Platnick, S King, MD Minnis, P Yang, P TI Evaluation of cirrus cloud properties derived from MODIS data using cloud properties derived from ground-based observations collected at the ARM SGP site SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID PARTICLE-SIZE SPECTRA; ICE WATER-CONTENT; RADIATIVE PROPERTIES; MICROPHYSICAL PROPERTIES; TERMINAL VELOCITIES; EFFECTIVE RADIUS; RADAR; CLIMATE; STATISTICS; HIRS AB The Moderate Resolution Imaging Spectroradiometer (MODIS) on board the NASA Terra satellite has been collecting global data since March 2000 and the one on the Aqua satellite since June 2002. In this paper, citrus cloud properties derived from ground-based remote sensing data are compared with similar cloud properties derived from MODIS data on Terra. To improve the space-time correlation between the satellite and ground-based observations, data from a wind profiler are used to define the cloud advective streamline along which the comparisons are made. In this paper, approximately two dozen cases of cirrus are examined and a statistical approach to the comparison that relaxes the requirement that clouds occur over the ground-based instruments during the overpass instant is explored. The statistical comparison includes 168 cloudy MODIS overpasses of the Southern Great Plains (SGP) region and approximately 300 It of ground-based cirrus observations. The physical and radiative properties of cloud layers are derived from MODIS data separately by the MODIS Atmospheres Team and the Clouds and the Earth's Radiant Energy System (CERES) Science Team using multiwavelength reflected solar and emitted thermal radiation measurements. Using two ground-based cloud property retrieval algorithms and the two MODIS algorithms, a positive correlation in the effective particle size, the optical thickness, the ice water path. and the cloud-top pressure between the various methods is shown, although sometimes there are significant biases. Classifying the clouds by optical thickness, it is demonstrated that the regionally averaged cloud properties derived from MODIS are similar to those diagnosed from the ground. Because of a conservative approach toward identifying thin cirrus pixels over this region, the area-averaged cloud properties derived from the MODIS Atmospheres MOD06 product tend to be biased slightly toward the optically thicker pixels. This bias tendency has implications for model validation and parameterization development applied to thin cirrus retrieved over SGP-like land surfaces. A persistent bias is also found in the derived cloud tops of thin cirrus with both satellite algorithms reporting cloud top several hundred meters less than that reported by the cloud radar. Overall, however, it is concluded that the MODIS retrieval algorithms characterize with reasonable accuracy the properties of thin cirrus over this region. C1 Univ Utah, Dept Meteorol, Salt Lake City, UT 84112 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. NASA, Langley Res Ctr, Langley, VA USA. Texas A&M Univ, College Stn, TX USA. RP Mace, GG (reprint author), Univ Utah, Dept Meteorol, Rm 819 819 WBB,135S 1460E, Salt Lake City, UT 84112 USA. EM mace@met.utah.edu RI Yang, Ping/B-4590-2011; King, Michael/C-7153-2011; Platnick, Steven/J-9982-2014; Zhang, Yuying/H-5011-2012; Minnis, Patrick/G-1902-2010 OI King, Michael/0000-0003-2645-7298; Platnick, Steven/0000-0003-3964-3567; Minnis, Patrick/0000-0002-4733-6148 NR 48 TC 61 Z9 62 U1 1 U2 8 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 FEB PY 2005 VL 44 IS 2 BP 221 EP 240 DI 10.1175/JAM2193.1 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 910SX UT WOS:000227953600003 ER PT J AU Xu, TB Su, J AF Xu, TB Su, J TI Theoretical modeling of electroactive polymer-ceramic hybrid actuation systems SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID POLY(VINYLIDENE FLUORIDE-TRIFLUOROETHYLENE) COPOLYMER; ELECTROMECHANICAL PROPERTIES; SINGLE-CRYSTALS; ELECTROSTRICTION; PERFORMANCE AB An electroactive polymer-ceramic hybrid actuation system (HYBAS) was recently developed. The HYBAS demonstrates significantly enhanced electromechanical performance by utilizing the advantages of cooperative contributions of the electromechanical responses of an electrostrictive copolymer and an electrostrictive single crystal. The hybrid actuation system provides not only a device but also a concept to utilize different electroactive materials in a cooperative and efficient method for optimized electromechanical performance. In order to develop an effective procedure to optimize the performance of a HYBAS, a theoretical model has been developed based on the elastic and electromechanical properties of the materials utilized in the system and on the configuration of the device. The model also evaluates performance optimization as a function of geometric parameters, including the length of the HYBAS and the thickness ratios of the constituent components. Comparison of the model with the experimental results shows good agreement and validates the model as an effective method for the further development of high-performance actuating devices or systems for various applications. (C) 2005 American Institute of Physics. C1 NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. Natl Inst Aerosp, Hampton, VA 23666 USA. RP Su, J (reprint author), NASA, Langley Res Ctr, Adv Mat & Proc Branch, Hampton, VA 23681 USA. EM ji.su-1@nasa.gov NR 23 TC 20 Z9 20 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD FEB 1 PY 2005 VL 97 IS 3 AR 034908 DI 10.1063/1.1844616 PG 7 WC Physics, Applied SC Physics GA 894GG UT WOS:000226778300093 ER PT J AU Iwaniec, UT Wronski, TJ Amblard, D Nishimura, Y van der Meulen, MCH Wade, CE Bourgeois, MA Damsky, CD Globus, RK AF Iwaniec, UT Wronski, TJ Amblard, D Nishimura, Y van der Meulen, MCH Wade, CE Bourgeois, MA Damsky, CD Globus, RK TI Effects of disrupted beta(1)-integrin function on the skeletal response to short-term hindlimb unloading in mice SO JOURNAL OF APPLIED PHYSIOLOGY LA English DT Article DE cancellous bone; bone formation; bone resorption; bone strength ID SUSPENSION-INDUCED OSTEOPENIA; INHIBITS BONE-FORMATION; TAIL SUSPENSION; BIOCHEMICAL MARKERS; MESSENGER-RNA; GROWING RATS; SPACE-FLIGHT; BED REST; MICROCOMPUTED TOMOGRAPHY; MECHANICAL STIMULATION AB The study was designed to determine whether beta(1)-integrin plays a role in mediating the acute skeletal response to mechanical unloading. Transgenic (TG) mice were generated to express a dominant negative form of beta(1)-integrin under the control of the osteocalcin promoter, which targets expression of the transgene to mature osteoblasts. At 63 days of age, wild-type (WT) and TG mice were subjected to hindlimb unloading by tail suspension for 1 wk. Pair-fed, normally loaded WT and TG mice served as age-matched controls. Bone samples from each mouse were processed for quantitative bone histomorphometry and biomechanical testing. The skeletal phenotype of TG mice was characterized by lower cancellous bone mass in the distal femoral metaphysis (-52%) and lumbar vertebral body (-20%), reduced curvature of the proximal tibia (-20%), and decreased bone strength (-20%) and stiffness (-23%) of the femoral diaphysis with relatively normal indexes of cancellous bone turnover. Hindlimb unloading for only 1 wk induced a 10% decline in tibial curvature and a 30% loss of cancellous bone in the distal femur due to a combination of increased bone resorption and decreased bone formation in both WT and TG mice. However, the strength and stiffness of the femoral diaphysis were unaffected by short-term hindlimb unloading in both genotypes. The observed increase in osteoclast surface was greater in unloaded TG mice (92%) than in unloaded WT mice (52%). Cancellous bone formation rate was decreased in unloaded WT (-29%) and TG (-15%) mice, but, in contrast to osteoclast surface, the genotype by loading interaction was not statistically significant. The results indicate that altered integrin function in mature osteoblasts may enhance the osteoclastic response to mechanical unloading but that it does not have a major effect on the development of cancellous osteopenia in mice during the early stages of hindlimb unloading. C1 Univ Florida, Dept Physiol Sci, Gainesville, FL 32610 USA. NASA, Ames Res Ctr, Div Life Sci, Moffett Field, CA 94035 USA. Cornell Univ, Sibley Sch Mech & Aerosp Engn, Ithaca, NY 14853 USA. Univ Calif San Francisco, Dept Stomatol, San Francisco, CA 94143 USA. RP Iwaniec, UT (reprint author), Univ Florida, Dept Physiol Sci, Box 100144,JHMHC, Gainesville, FL 32610 USA. EM iwaniecu@mail.vetmed.ufl.edu RI van der Meulen, Marjolein/D-1549-2010 OI van der Meulen, Marjolein/0000-0001-6637-9808 FU NIDCR NIH HHS [P60 DE-13058] NR 58 TC 24 Z9 24 U1 0 U2 0 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 8750-7587 J9 J APPL PHYSIOL JI J. Appl. Physiol. PD FEB PY 2005 VL 98 IS 2 BP 690 EP 696 DI 10.1152/japplphysiol.00689.2004 PG 7 WC Physiology; Sport Sciences SC Physiology; Sport Sciences GA 887CZ UT WOS:000226282400037 PM 15465888 ER PT J AU Kato, S Rose, FG Charlock, TP AF Kato, S Rose, FG Charlock, TP TI Computation of domain-averaged irradiance using satellite-derived cloud properties SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ATMOSPHERE RADIATIVE FLUXES; BOUNDARY-LAYER CLOUDS; ISCCP DATA SETS; SOLAR FLUXES; PARAMETERIZATION; MODELS; APPROXIMATION; ALBEDO; BUDGET; TOP AB The respective errors caused by the gamma-weighted two-stream approximation and the effective thickness approximation for computing the domain-averaged broadband shortwave irradiance are evaluated using cloud optical thicknesses derived from 1 h of radiance measurements by the Moderate Resolution Imaging Spectrometer (MODIS) over footprints of Clouds and the Earth's Radiant Energy System (CERES) instruments. Domains are CERES footprints of which dimension varies approximately from 20 to 70 km, depending on the viewing zenith angle of the instruments. The average error in the top-of-atmosphere irradiance at a 30degrees solar zenith angle caused by the gamma-weighted two-stream approximation is 6.1 W m(-2) (0.005 albedo bias) with a one-layer overcast cloud where a positive value indicates an overestimate by the approximation compared with the irradiance computed using the independent column approximation. Approximately one-half of the error is due to deviations of optical thickness distributions from a gamma distribution and the other half of the error is due to other approximations in the model. The error increases to 14.7 W m(-2) (0.012 albedo bias) when the computational layer dividing the cloud layer is increased to four. The increase is because of difficulties in treating the correlation of cloud properties in the vertical direction. Because the optical thickness under partly cloudy conditions, which contribute two-thirds of cloudy footprints, is smaller, the error is smaller than under overcast conditions;, the average error for partly cloudy condition is -2.4 W m(-2) (-0.002 albedo bias) at a 30degrees solar zenith angle. The corresponding average error caused by the effective thickness approximation is 0.5 W m(-2) for overcast conditions and -21.5 W m(-2) (-0.018 albedo bias) for partly cloudy conditions. Although the error caused by the effective thickness approximation depends strongly on the optical thickness, its average error under overcast conditions is smaller than the error caused by the gamma-weighted two-stream approximation because the errors at small and large optical thicknesses cancel each other. Based on these error analyses, the daily average error caused by the gamma-weighted two-stream and effective thickness approximations is less than 2 W m(-2). C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Hampton Univ, Ctr Atmospher Sci, Hampton, VA 23668 USA. Analyt Serv & Mat Inc, Hampton, VA 23666 USA. RP Kato, S (reprint author), NASA, Langley Res Ctr, Mail Stop 420, Hampton, VA 23681 USA. EM s.kato@larc.nasa.gov OI Rose, Fred G/0000-0003-0769-0772 NR 33 TC 32 Z9 32 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD FEB PY 2005 VL 22 IS 2 BP 146 EP 164 DI 10.1175/JTECH-1694.1 PG 19 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA 897XW UT WOS:000227041200003 ER PT J AU Wu, CC Lepping, RP AF Wu, CC Lepping, RP TI Relationships for predicting magnetic cloud-related geomagnetic storm intensity SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article DE magnetic cloud; geomagnetic storm; storm intensity prediction ID SOLAR-WIND; MAGNETOSPHERE; INDEX AB Studying geomagnetic storm activity during 135 interplanetary magnetic cloud periods from 1965 to 1998, Wu and Lepping (J. Geophys. Res. 107 (2002b) 1346) found that the storm Dst index correlated well with both the interplanetary magnetic field z-component (B-z) and the "rectified" electric field VBs but did not correlate well with solar wind speed. It is shown that the role of magnetic cloud speed in predicting storm intensity is a minor one. It also was found that the correlation coefficient for Dst vs. B, increases dramatically when the solar wind speed exceeds 600 km/s. This implies that solar wind speed is also important indirectly for predicting the storm intensity when using B-z (or VBs) as a direct predictor. Using the same data set of 135 magnetic cloud-associated storms, two Dst prediction-relationships were developed: one is velocity independent and the other is velocity dependent. In this study, (i) both Dst prediction-relationships will be presented and (ii) some recent storm events will be presented and discussed by (as examples) using both Dst prediction-relationships. The results of this study also show: (1) The intensity of a magnetic storm which is associated with a magnetic cloud is predictable. (2) The prediction relationships for storm intensity, Dst(min) are: Dst(min) = 0.83 + 7.85 x Bz(min) and Dst(min) = -16.48-12.89 x (VBs)(max). (3) The velocity dependence of the Dst(min) prediction relationship will improve the accuracy for a Bz-base prediction result. (4) For the VBsmax-based prediction relationship, the prediction accuracy of Dst(min) becomes worse when a velocity-dependent prediction relationship is used. (C) 2004 Published by Elsevier Ltd. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Univ Alabama, CSPAR, Huntsville, AL 35899 USA. RP Wu, CC (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. EM ccwu@lepccwu.gsfc.nasa.gov NR 32 TC 25 Z9 26 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD FEB PY 2005 VL 67 IS 3 BP 283 EP 291 DI 10.1016/j.jastp.2004.04.040 PG 9 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA 893GJ UT WOS:000226707000008 ER PT J AU Rinkus, S Walji, M Johnson-Throop, KA Malin, JT Turley, JP Smith, JW Zhang, JJ AF Rinkus, S Walji, M Johnson-Throop, KA Malin, JT Turley, JP Smith, JW Zhang, JJ TI Human-centered design of a distributed knowledge management system SO JOURNAL OF BIOMEDICAL INFORMATICS LA English DT Article DE human-centered computing; organizational memory; knowledge management; collaborative; groupware; information systems; design; ethnographic; project lifecycle ID ORGANIZATIONAL MEMORY; INFORMATION-SYSTEMS; ENTERPRISE AB Many healthcare technology projects fail due to the lack of consideration of human issues, such as workflow, organizational change, and usability, during the design and implementation stages of a project's development process. Even when human issues are considered, the consideration is typically on designing better user interfaces. We argue that human-centered computing goes beyond a better user interface: it should include considerations of users, functions and tasks that are fundamental to human-centered computing. From this perspective, we integrated a previously developed human-centered methodology with a Project Design Lifecycle, and we applied this integration in the design of a complex distributed knowledge management system for the Biomedical Engineer (BME) domain in the Mission Control Center at NASA Johnson Space Center. We analyzed this complex system, identified its problems, generated systems requirements, and provided specifications of a replacement prototype for effective organizational memory and knowledge management. We demonstrated the value provided by our human-centered approach and described the unique properties, structures, and processes discovered using this methodology and how they contributed in the design of the prototype. (C) 2004 Elsevier Inc. All rights reserved. C1 Univ Texas, Sch Hlth Informat Sci, Houston, TX 77030 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Zhang, JJ (reprint author), Univ Texas, Sch Hlth Informat Sci, 7000 Fannin,Suite 600, Houston, TX 77030 USA. EM susan_rinkus@yahoo.com; Jiajie.Zhang@uth.tmc.edu FU NLM NIH HHS [5T15LM07093] NR 34 TC 37 Z9 39 U1 1 U2 19 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1532-0464 J9 J BIOMED INFORM JI J. Biomed. Inform. PD FEB PY 2005 VL 38 IS 1 BP 4 EP 17 DI 10.1016/j.jbi.2004.11.014 PG 14 WC Computer Science, Interdisciplinary Applications; Medical Informatics SC Computer Science; Medical Informatics GA 900EH UT WOS:000227197700002 PM 15694881 ER PT J AU Smith, SM Wastney, ME O'Brien, K Morukov, BV Larina, IM Abrams, SA Davis-Street, JE Oganov, V Shackelford, LC AF Smith, SM Wastney, ME O'Brien, K Morukov, BV Larina, IM Abrams, SA Davis-Street, JE Oganov, V Shackelford, LC TI Bone markers, calcium metabolism, and calcium kinetics during extended-duration space flight on the Mir space station SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Article DE weightlessness; calcium absorption; mathematical modeling; stable isotopes; microgravity ID BED-REST; EXCRETION; WEIGHTLESSNESS; COUNTERMEASURE; SPACEFLIGHT; ABSORPTION; RESORPTION; COSMONAUTS; TURNOVER; EXERCISE AB Bone loss is a current limitation for long-term space exploration. Bone markers, calcitropic hormones, and calcium kinetics of crew members on space missions of 4-6 months were evaluated. Spaceflight-induced bone loss was associated with increased bone resorption and decreased calcium absorption. C1 NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Off, Houston, TX 77058 USA. Metab Modeling Serv Inc, Hamilton, New Zealand. Johns Hopkins Univ, Bloomberg Sch Publ Hlth, Div Human Nutr, Baltimore, MD USA. Inst Biomed Problems, Moscow, Russia. Baylor Coll Med, Childrens Nutr Res Ctr, USDA ARS, Dept Pediat, Houston, TX 77030 USA. Enterprise Advisory Serv Inc, Houston, TX USA. RP Smith, SM (reprint author), NASA, Lyndon B Johnson Space Ctr, Human Adaptat & Countermeasures Off, SK3, Houston, TX 77058 USA. EM scott.m.smith@nasa.gov OI Abrams, Steven/0000-0003-4972-9233 NR 38 TC 108 Z9 122 U1 2 U2 17 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 FEB PY 2005 VL 20 IS 2 BP 208 EP 218 DI 10.1359/JBMR.041105 PG 11 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 889RT UT WOS:000226460800005 PM 15647814 ER PT J AU Lien, MC McCann, RS Ruthruff, E Proctor, RW AF Lien, MC McCann, RS Ruthruff, E Proctor, RW TI Dual-task performance with ideomotor-compatible tasks: Is the central processing bottleneck intact, bypassed, or shifted in locus? SO JOURNAL OF EXPERIMENTAL PSYCHOLOGY-HUMAN PERCEPTION AND PERFORMANCE LA English DT Article ID PSYCHOLOGICAL REFRACTORY-PERIOD; EXECUTIVE COGNITIVE-PROCESSES; PARALLEL RESPONSE SELECTION; 2 THINGS; COMPUTATIONAL THEORY; CENTRAL POSTPONEMENT; OVERLAPPING TASKS; INTERFERENCE AB The present study examined whether the central bottleneck, assumed to be primarily responsible for the psychological refractory period (PRP) effect, is intact, bypassed, or shifted in locus with ideomotor (IM)-compatible tasks. In 4 experiments, factorial combinations of IM- and non-IM-compatible tasks were used for Task I and Task 2. All experiments showed substantial PRP effects, with a strong dependency between Task 1 and Task 2 response times. These findings, along with model-based simulations, indicate that the processing bottleneck was not bypassed, even with two IM-compatible tasks. Nevertheless, systematic changes in the PRP and correspondence effects across experiments suggest that IM compatibility shifted the locus of the bottleneck. The findings favor an engage-bottleneck-later hypothesis, whereby parallelism between tasks occurs deeper into the processing stream for IM- than for non-IM-compatible tasks, without the bottleneck being actually eliminated. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Purdue Univ, Dept Psychol Sci, W Lafayette, IN 47907 USA. RP Lien, MC (reprint author), Oregon State Univ, Dept Psychol, 204C Moreland Hall, Corvallis, OR 97331 USA. EM mei.lien@oregonstate.edu NR 49 TC 36 Z9 36 U1 0 U2 5 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 FEB PY 2005 VL 31 IS 1 BP 122 EP 144 DI 10.1037/0096-1523.31.1.122 PG 23 WC Psychology; Psychology, Experimental SC Psychology GA 897QH UT WOS:000227019200010 PM 15709868 ER PT J AU Lien, MC McCann, RS Ruthruff, E AF Lien, MC McCann, RS Ruthruff, E TI Confirming and disconfirming theories about ideomotor compatibility in dual-task performance: A reply to Greenwald (2005) SO JOURNAL OF EXPERIMENTAL PSYCHOLOGY-HUMAN PERCEPTION AND PERFORMANCE LA English DT Editorial Material ID REFRACTORY PERIOD PARADIGM; INTERFERENCE AB Because small dual-task costs with ideomotor-compatible tasks do not necessarily indicate the absence of a bottleneck, M.-C. Lien, R. S. McCann, E. Ruthruff, and R. W. Proctor (2005) considered additional sources of evidence regarding bottleneck bypass. This evidence argued against complete bottleneck bypass and, instead, supported an engage-bottleneck-later model in which early bottleneck substages are bypassed but late substages are not. A. G. Greenwald (2005), however, contended that M.-C. Lien et al. (2005) did not use the procedures needed to produce complete bottleneck bypass and that a complete bottleneck bypass hypothesis, combined with additional assumptions, could explain their data. The authors contend that this disagreement stems from Greenwald's focus on confirming predictions of complete bottleneck bypass (small dual-task costs) without disconfirming predictions of bottleneck presence. In particular, Greenwald neglects to consider the possibility that a latent bottleneck limitation could also produce small dual-task costs. C1 Oregon State Univ, Dept Psychol, Corvallis, OR 97331 USA. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. Purdue Univ, Dept Psychol Sci, W Lafayette, IN 47907 USA. RP Lien, MC (reprint author), Oregon State Univ, Dept Psychol, 204C Moreland Hall, Corvallis, OR 97331 USA. EM mei.lien@oregonstate.edu NR 17 TC 4 Z9 4 U1 1 U2 1 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 FEB PY 2005 VL 31 IS 1 BP 226 EP 229 DI 10.1037/0096-1523.31.1.226 PG 4 WC Psychology; Psychology, Experimental SC Psychology GA 897QH UT WOS:000227019200018 PM 15709876 ER PT J AU Librescu, L Marzocca, P Silva, WA AF Librescu, L Marzocca, P Silva, WA TI Aeroelasticity of 2-D lifting surfaces with time-delayed feedback control SO JOURNAL OF FLUIDS AND STRUCTURES LA English DT Article ID CHAOTIC MOTIONS; SYSTEMS; STABILITY AB Two basic issues related to the open/closed-loop aeroelasticity of 2-D lifting surfaces in an incompressible flow field are considered. These concern the subcritical aeroelastic response to external time-dependent excitations, and the flutter instability of actively controlled airfoils involving a time-delayed feedback control. Results and comparisons regarding the flutter instability obtained via the first Volterra kernel in conjunction with a frequency eigenvalue analysis are presented. In the same context, the implications on the instability boundary and aeroelastic response of the presence of time-delays in the feedback control are investigated and pertinent conclusions are supplied. (C) 2004 Elsevier Ltd. All rights reserved. C1 Virginia Polytech Inst & State Univ, Dept Engn Sci & Mech, Blacksburg, VA 24061 USA. Clarkson Univ, Dept Mech & Aeronaut Engn, Potsdam, NY 13699 USA. NASA, Langley Res Ctr, Aeroelast Branch, Struct & Mat Competency, 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. EM librescu@vt.edu NR 21 TC 22 Z9 27 U1 1 U2 4 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0889-9746 J9 J FLUID STRUCT JI J. Fluids Struct. PD FEB PY 2005 VL 20 IS 2 BP 197 EP 215 DI 10.1016/j.jfluidstructs.2004.10.005 PG 19 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 904OX UT WOS:000227508700004 ER PT J AU Chang, ATC Kelly, REJ Josberger, EG Armstrong, RL Foster, JL Mognard, NM AF Chang, ATC Kelly, REJ Josberger, EG Armstrong, RL Foster, JL Mognard, NM TI Analysis of ground-measured and passive-microwave-derived snow depth variations in midwinter across the northern Great Plains SO JOURNAL OF HYDROMETEOROLOGY LA English DT Article ID WATER EQUIVALENT; ALGORITHM; PRECIPITATION; RAINFALL; IMAGERY; ERRORS; METAMORPHISM; PREDICTION; PARAMETERS; EXTENT AB Accurate estimation of snow mass is important for the characterization of the hydrological cycle at different space and time scales. For effective water resources management, accurate estimation of snow storage is needed. Conventionally; snow depth is measured at a point, and in order to monitor snow depth in a temporally and spatially comprehensive manner, optimum interpolation of the points is undertaken. Yet the spatial representation of point measurements at a basin or on a larger distance scale is uncertain. Spaceborne scanning sensors, which cover a wide swath and can provide rapid repeat global coverage are ideally suited to augment the global snow information. Satellite-borne passive microwave sensors have been used to derive snow depth (SD) with some success. The uncertainties in point SD and areal SD of natural snowpacks need to be understood if comparisons are to be made between a point SD measurement and satellite SD. In this paper three issues are addressed relating satellite derivation of SD and ground measurements of SD in the northern Great Plains of the United States from 1988 to 1997. First, it is shown that in comparing samples of ground-measured point SD data with satellite-derived 25 X 25 km(2) pixels of SD from the Defense Meteorological Satellite Program Special Sensor Microwave Imager, there are significant differences in yearly SD values even though the accumulated datasets showed similarities. Second, from variogram analysis, the spatial variability of SD from each dataset was comparable. Third, for a sampling grid cell domain of 1degrees x 1degrees in the study terrain, 10 distributed snow depth measurements per cell are required to produce a sampling error of 5 cm or better. This study has important implications for validating SD derivations from satellite microwave observations. C1 NASA, Hydrol Sci Branch, Lab Hydrospher Proc, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. US Geol Survey, Tacoma, WA USA. Univ Colorado, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA. Ctr Etud Spatiales Biosphere, Toulouse, France. RP Kelly, REJ (reprint author), NASA, Hydrol Sci Branch, Lab Hydrospher Proc, Goddard Space Flight Ctr, Code 974,Bldg 33, Greenbelt, MD 20771 USA. EM rkelly@glacier.gsfc.nasa.gov NR 38 TC 35 Z9 35 U1 1 U2 13 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 FEB PY 2005 VL 6 IS 1 BP 20 EP 33 DI 10.1175/JHM-405.1 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 903OT UT WOS:000227436100002 ER PT J AU Li, L Roden, J Shapiro, BE Wold, BJ Bhatia, S Forman, SJ Bhatia, R AF Li, L Roden, J Shapiro, BE Wold, BJ Bhatia, S Forman, SJ Bhatia, R TI Reproducibility, fidelity, and discriminant validity of mRNA amplification for microarray analysis from primary hematopoietic cells SO JOURNAL OF MOLECULAR DIAGNOSTICS LA English DT Article ID GENE-EXPRESSION PROFILES; ACUTE MYELOID-LEUKEMIA; OLIGONUCLEOTIDE ARRAYS; SUBTYPES AB Analysis of gene expression in clinical samples poses special challenges, including limited RNA availability and poor RNA quality. Quantitative information regarding reliability of RNA amplification methodologies applied to primary cells and representativeness of resulting gene expression profiles is limited. We evaluated four protocols for RNA amplification from peripheral blood mononuclear cells. Results obtained with 100 ng or 10 ng of RNA amplified using two rounds of cDNA synthesis and in vitro transcription were compared with control 2.5-mu g RNA samples processed using a single round of in vitro transcription. Samples were hybridized to Affymetrix HG-U133A arrays. Considerable differences in results were obtained with different protocols. The optimal protocol resulted in highly reproducible gene expression profiles from amplified samples (r = 0.98) and good correlation between amplified and control samples (r = 0.94). Using the optimal protocol dissimilarities of gene expression between mononuclear cells from a normal individual and a patient with myelodysplastic syndrome were primarily maintained after amplification compared with controls. We conclude that small variations in methodology introduce considerable distortion of gene expression profiles obtained after RNA amplification from clinical samples and too strong a focus on a very small number of genes picked from an array analysis could be unduly influenced by seemingly acceptable methodologies. However, it is possible to obtain reproducible and representative results using optimized protocols. C1 City Hope Natl Med Ctr, Div Hematol Bone Marrow Transplantat, Duarte, CA 91010 USA. City Hope Natl Med Ctr, Div Pediat, Duarte, CA 91010 USA. Jet Propuls Lab, Machine Learning Syst Grp, Pasadena, CA USA. CALTECH, Pasadena, CA 91125 USA. RP Bhatia, R (reprint author), City Hope Natl Med Ctr, Div Hematol Bone Marrow Transplantat, 1500 E Duarte Rd, Duarte, CA 91010 USA. EM rbhatia@coh.org FU NCRR NIH HHS [5M01 RR00043, M01 RR000043] NR 14 TC 33 Z9 44 U1 0 U2 0 PU AMER SOC INVESTIGATIVE PATHOLOGY, INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3993 USA SN 1525-1578 J9 J MOL DIAGN JI J. Mol. Diagn. PD FEB PY 2005 VL 7 IS 1 BP 48 EP 56 DI 10.1016/S1525-1578(10)60008-6 PG 9 WC Pathology SC Pathology GA 908XQ UT WOS:000227823900007 PM 15681474 ER PT J AU Ohshima, KI Nihashi, S AF Ohshima, KI Nihashi, S TI A simplified ice-ocean coupled model for the Antarctic ice melt season SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID SOUTHERN-OCEAN; WEDDELL SEA; PACK ICE; MIXED LAYER; SIMULATION; DYNAMICS; VARIABILITY; CIRCULATION; SYSTEM; MOTION AB In the Antarctic Ocean, sea ice melts mostly by warming of the ocean mixed layer through heat input (mainly solar radiation) in open water areas. A simplified ice-upper ocean coupled model is proposed in which sea ice melts only by the ocean heat supplied from the air. The model shows that the relationship between ice concentration (i.e., fraction, C) and mixed layer temperature (T) converges asymptotically with time (C-T relationship), which agrees with observed C-T plots during summer in the sector 25 degrees-45 degrees E. This relationship can be used for estimating the bulk heat transfer coefficient between ice and ocean by fitting to observations, and a value of 1.2 X 10(-4) m s(-1) is obtained. The model shows that the ratio of the heat used for melting to the heat input through open water is inclined to be determined as a function of ice concentration. For typical conditions in the Antarctic ice melt season, the ratio ranges mostly between 0.7 and 0.9. When the model is extended to two dimensions in the meridional direction, with the inclusion of wind forcing, it approximately reproduces the meridional retreat of the Antarctic sea ice. This two-dimensional model can describe the open water-albedo feedback effect, which partly explains the year-to-year variation of the sea-ice retreat in the Antarctic Ocean. C1 Hokkaido Univ, Inst Low Temp Sci, Kita Ku, Sapporo, Hokkaido 0600819, Japan. NASA, Lab Hydrospher Proc, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Ohshima, KI (reprint author), Hokkaido Univ, Inst Low Temp Sci, Kita Ku, Kita 19,Nishi 8, Sapporo, Hokkaido 0600819, Japan. EM ohshima@lowtem.hokudai.ac.jp RI Ohshima, Kay/D-6909-2012 NR 39 TC 12 Z9 12 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD FEB PY 2005 VL 35 IS 2 BP 188 EP 201 DI 10.1175/JPO-2675.1 PG 14 WC Oceanography SC Oceanography GA 908NS UT WOS:000227794300005 ER PT J AU Jacobson, N Myers, D Opila, E Copland, E AF Jacobson, N Myers, D Opila, E Copland, E TI Interactions of water vapor with oxides at elevated temperatures SO JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS LA English DT Article; Proceedings Paper CT 11th International Conference on High Temperature materials Chemistry (HTMC-XI) CY MAY 19-23, 2003 CL Tokyo, JAPAN ID SIO2 SCALE VOLATILITY; COMBUSTION CONDITIONS; MASS SPECTROMETRY; GASEOUS SIO(OH); HYDROXIDE; THERMOCHEMISTRY; THERMODYNAMICS; OXIDATION; ENVIRONMENTS; COMPOSITES AB Many volatile metal hydroxides form by reaction of the corresponding metal oxide with water vapor. These reactions are important in a number of high temperature corrosion processes. Experimental methods for studying the thermodynamics of metal hydroxides include: gas leak Knudsen cell mass spectrometry, free jet sampling mass spectrometry, transpiration and hydrogen-oxygen flame studies. The available experimental information is reviewed and the most stable metal hydroxide species are correlated with position in the periodic table. Current studies in our laboratory on the Si-O-H system are discussed. (c) 2004 Elsevier Ltd. All rights reserved. C1 Case Western Reserve Univ, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. E Cent Univ, Ada, OK 74820 USA. RP Jacobson, N (reprint author), Case Western Reserve Univ, NASA, Glenn Res Ctr, Cleveland, OH 44135 USA. RI Jacobson, Nathan/A-9411-2009 NR 52 TC 42 Z9 43 U1 0 U2 20 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-3697 J9 J PHYS CHEM SOLIDS JI J. Phys. Chem. Solids PD FEB-APR PY 2005 VL 66 IS 2-4 SI SI BP 471 EP 478 DI 10.1016/j.jpcs.2004.06.044 PG 8 WC Chemistry, Multidisciplinary; Physics, Condensed Matter SC Chemistry; Physics GA 905NW UT WOS:000227576500051 ER PT J AU Yang, Z Wennberg, PO Cageao, RP Pongetti, TJ Toon, GC Sander, SP AF Yang, Z Wennberg, PO Cageao, RP Pongetti, TJ Toon, GC Sander, SP TI Ground-based photon path measurements from solar absorption spectra of the O-2 A-band SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE O-2 A-band; photon path; solar absorption spectra ID OXYGEN; PARAMETERS; SPECTROSCOPY AB High-resolution solar absorption spectra obtained from Table Mountain Facility (TMF, 34.38degreesN, 117.68degreesW, 2286 m elevation) have been analyzed in the region of the O-2 A-band. The photon paths of direct sunlight in clear sky cases are retrieved from the O-2 absorption lines and compared with ray-tracing calculations based on the solar zenith angle and surface pressure. At a given zenith angle, the ratios of retrieved to geometrically derived photon paths are highly precise (similar to0.2%), but they vary as the zenith angle changes. This is because current models of the spectral lineshape in this band do not properly account for the significant absorption that exists far from the centers of saturated lines. For example, use of a Voigt function with Lorentzian far wings results in an error in the retrieved photon path of as much as 5%, highly correlated with solar zenith angle. Adopting a super-Lorentz function reduces, but does not completely eliminate this problem. New lab measurements of the lineshape are required to make further progress. (C) 2004 Elsevier Ltd. All rights reserved. C1 CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Yang, Z (reprint author), CALTECH, 1200 E Calif Blvd, Pasadena, CA 91125 USA. EM yangzh@gps.caltech.edu RI Wennberg, Paul/A-5460-2012 NR 19 TC 31 Z9 33 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD FEB 1 PY 2005 VL 90 IS 3-4 BP 309 EP 321 DI 10.1016/j.jqsrt.2004.03.020 PG 13 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 864XV UT WOS:000224667500004 ER PT J AU Kratz, DP Mlynczak, MG Mertens, CJ Brindley, H Gordley, LL Martin-Torres, J Miskolczi, FM Turner, DD AF Kratz, DP Mlynczak, MG Mertens, CJ Brindley, H Gordley, LL Martin-Torres, J Miskolczi, FM Turner, DD TI An inter-comparison of far-infrared line-by-line radiative transfer models SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE far-infrared; FIRST; line-by-line; inter-comparison ID MOLECULAR SPECTROSCOPIC DATABASE; WATER-VAPOR ABSORPTION; ATMOSPHERIC FLUXES; COOLING RATES; CERES WINDOW; SENSITIVITY; CLOUDS; PARAMETERIZATION; RESOLUTION; RADIANCES AB A considerable fraction (>40%) of the outgoing longwave radiation escapes from the Earth's atmosphere-surface system within a region of the spectrum known as the far-infrared (wave-numbers less than 650 cm(-1)). Dominated by the line and continuum spectral features of the pure rotation band of water vapor, the far-infrared has a strong influence upon the radiative balance of the troposphere, and hence upon the climate of the Earth. Despite the importance of the far-infrared contribution, however, very few spectrally resolved observations have been made of the atmosphere for wave-numbers less than 650 cm(-1). The National Aeronautics and Space Administration (NASA), under its Instrument Incubator Program (IIP), is currently developing technology that will enable routine, space-based spectral measurements of the far-infrared. As part of NASA's IIP, the Far-Infrared Spectroscopy of the Troposphere (FIRST) project is developing an instrument that will have the capability of measuring the spectrum over the range from 100 to 1000 cm(-1) at a resolution of 0.6 cm(-1). To properly analyze the data from the FIRST instrument, accurate radiative transfer models will be required. Unlike the mid-infrared, however, no inter-comparison of codes has been performed for the far-infrared. Thus, in parallel with the development of the FIRST instrument, an investigation has been under-taken to inter-compare radiative transfer models for potential use in the analysis of far-infrared measurements. The initial phase of this investigation has focused upon the inter-comparison of six distinct line-by-line models. The results from this study have demonstrated remarkably good agreement among the models, with differences being of order 0.5%, thereby providing a high measure of confidence in our ability to accurately compute spectral radiances in the far-infrared. (C) 2004 Elsevier Ltd. All rights reserved. C1 NASA, Langley Res Ctr, Radiat & Aerosols Branch, Hampton, VA 23665 USA. Univ London Imperial Coll Sci Technol & Med, Space & Atmospher Phys Grp, London, England. G&A Tech Software Inc, Hampton, VA USA. Analyt Serv & Mat Inc, Hampton, VA USA. Pacific NW Natl Lab, Richland, WA USA. RP Kratz, DP (reprint author), NASA, Langley Res Ctr, Radiat & Aerosols Branch, Hampton, VA 23665 USA. EM david.p.kratz@nasa.gov RI Mlynczak, Martin/K-3396-2012; Martin-Torres, Francisco Javier/G-6329-2015; OI Martin-Torres, Francisco Javier/0000-0001-6479-2236; Brindley, Helen/0000-0002-7859-9207 NR 40 TC 25 Z9 25 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD FEB 1 PY 2005 VL 90 IS 3-4 BP 323 EP 341 DI 10.1016/j.jqsrt.2004.04.006 PG 19 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 864XV UT WOS:000224667500005 ER PT J AU Rinsland, CP Chiou, LS Goldman, A Wood, SW AF Rinsland, CP Chiou, LS Goldman, A Wood, SW TI Long-term trend in CHF2Cl (HCFC-22) from high spectral resolution infrared solar absorption measurements and comparison with in situ measurements SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article DE remote sensing; hydrochlorofluorocarbons; troposphere; atmospheric chemistry; ozone ID LOWER STRATOSPHERE; EARTHS ATMOSPHERE; ERROR ANALYSIS; CHCLF2; SF6; OZONE; ABUNDANCE; DATABASE; DECLINE; F-22 AB The average tropospheric volume mixing ratio of CHF2Cl (HCFC-22) has been retrieved from a time series of high spectral resolution ground-based infrared solar absorption spectra recorded with the McMath Fourier transform spectrometer located at the U.S. National Solar Observatory facility on Kitt Peak in southern Arizona (31.9degreesN, 111.6degreesW, 2.09 km altitude) for the time period October 1987-November 2002. The retrievals are based on fits to the well-isolated, unresolved 2v(6) Q branch at 829.05 cm(-1) and the SFIT2 retrieval algorithm. The measured daily averages show a near linear rise per year in the mean tropospheric volume mixing ratio as a function of time with a best fit yielding an average increase rate of (5.66 +/- 0.15) parts per trillion (10(-12)) by volume per year, corresponding to (6.47 +/- 0.17)%yr(-1), 1 sigma, at the beginning of the time series. The tropospheric mixing ratios retrieved from the solar spectra have been compared with monthly average surface flask sampling measurements from the Climate Monitoring and Diagnostic Laboratory (CMDL) station at Niwot Ridge, Colorado (40.0degreesN, 105.5degreesW, 3013 m altitude), archived measurement from the same location, and early CMDL northern hemisphere Pacific cruise measurements. The average ratio of the retrieved tropospheric mixing ratio relative to the CMDL surface mixing ratio is 1.053 for the overlapping 1987 to 2002 time period. The retrieved mean tropospheric mixing ratio is consistent with the surface measurements within the errors estimated for the remote sensing observations. (C) 2004 Elsevier Ltd. All fights reserved. C1 Natl Inst Water & Atmospher Res Ltd, Omakau, Cent Otago, New Zealand. NASA, Langley Res Ctr, Atmospher Sci Competency, Hampton, VA USA. Sci Applicat Int Corp, Hampton, VA USA. Univ Denver, Dept Phys, Denver, CO 80208 USA. RP Natl Inst Water & Atmospher Res Ltd, Private Bag 50061, Omakau, Cent Otago, New Zealand. EM curtis.p.rinsland@nasa.gov; goldman@acd.ucar.edu NR 33 TC 7 Z9 7 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0022-4073 EI 1879-1352 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD FEB 1 PY 2005 VL 90 IS 3-4 BP 367 EP 375 DI 10.1016/j.jqsrt.2004.04.008 PG 9 WC Optics; Spectroscopy SC Optics; Spectroscopy GA 864XV UT WOS:000224667500007 ER PT J AU Albarado, TL Hollerman, WA Edwards, D Hubbs, W Semmel, C AF Albarado, TL Hollerman, WA Edwards, D Hubbs, W Semmel, C TI Electron exposure measurements of candidate solar sail materials SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article DE solar sail; electron exposure; space radiation environment AB Solar sailing is a unique form of propulsion where a spacecraft gains momentum from incident photons. Since sails are not limited by reaction mass, they provide continual acceleration, reduced only by the lifetime of the lightweight film in the space environment and the distance to the Sun. Practical solar sails can expand the number of possible missions that are difficult by conventional means. The National Aeronautics and Space Administration's Marshall Space Flight Center (MSFC) is concentrating research into the utilization of ultra lightweight materials for spacecraft propulsion. Solar sails are generally composed of a highly reflective metallic front layer a thin polymeric substrate, and occasionally a highly emissive back surface. The Space Environmental Effects Team at MSFC is actively characterizing candidate sails to evaluate the thermo-optical and mechanical properties after exposure to electrons. This paper will discuss the preliminary results of this research. C1 Univ Louisiana, Dept Phys, Lafayette, LA 70504 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. Qualis Corp, Huntsville, AL 35806 USA. RP Albarado, TL (reprint author), Univ Louisiana, Dept Phys, POB 44210, Lafayette, LA 70504 USA. RI Hollerman, William/F-5943-2011 NR 16 TC 3 Z9 7 U1 1 U2 6 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA THREE PARK AVE, NEW YORK, NY 10016-5990 USA SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD FEB PY 2005 VL 127 IS 1 BP 125 EP 130 DI 10.1115/1.1823495 PG 6 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA 905OI UT WOS:000227577800018 ER PT J AU Yost, WT Macias, BR Cao, PH Hargens, AR Ueno, T AF Yost, WT Macias, BR Cao, PH Hargens, AR Ueno, T TI System for determination of ultrasonic wave speeds and their temperature dependence in liquids and in vitro tissues SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Article ID VELOCITY AB An interferometric technique capable of accurately measuring wave speed in liquids is reported. The hardware is adapted from a design to measure nonlinear responses of biological tissues to pressure changes (pressure derivatives) and temperature changes (temperature derivatives). It is used with the highly sensitive variable frequency pulsed phase-locked loop (VFPPLL) instrument. The system uses well-understood and well-characterized components and systems. The apparatus covers a temperature range from below 5 degreesC to above 45 degreesC. The system with the high-sensitivity VFPPLL is capable of measurement of wave speed to an uncertainty of less than 0.1%, and changes in wave speed to better than 0.001%. The transducer is an undamped temperature-characterized PZT-5A 500-kHz plate, whose output is corrected for off-resonance operation and for diffraction effects. To test the accuracy of the technique, measurement of ultrasonic compressional wave speed in water at temperatures from 10 degreesC to 45 degreesC are reported, with an estimated uncertainty of 0.07% and a temperature uncertainty of 0.15 degreesC. The agreement between mean values and literature values is better than 0.05%. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Univ Calif San Diego, San Diego, CA 92103 USA. RP Yost, WT (reprint author), NASA, Langley Res Ctr, MS 231, Hampton, VA 23681 USA. NR 13 TC 4 Z9 4 U1 0 U2 1 PU ACOUSTICAL SOC AMER AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD FEB PY 2005 VL 117 IS 2 BP 646 EP 652 DI 10.1121/1.1848176 PG 7 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA 897EN UT WOS:000226986900018 PM 15759685 ER PT J AU Wu, DL Read, WG Dessler, AE Sherwood, SC Jiang, JH AF Wu, DL Read, WG Dessler, AE Sherwood, SC Jiang, JH TI UARS/MLS cloud ice measurements: Implications for H2O transport near the tropopause SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID TROPICAL TROPOPAUSE; STRATOSPHERIC FOUNTAIN; MICROWAVE MEASUREMENTS; SIZE DISTRIBUTIONS; RADIATIVE-TRANSFER; CIRRUS CLOUDS; DEEP; PRECIPITATION; TEMPERATURES; DEHYDRATION AB A technique for detecting large hydrorneteors at high altitudes is described here and applied to the Upper Atmosphere Research Satellite/Microwave Limb Sounder (UARS/MLS) 203-GHz radiance measurements at tangent pressures between 200 and 46 hPa. At these tangent pressures the radiances remain optically thin and cloudy-sky radiances are brighter than normal clear-sky cases. Unlike infrared/visible cloud observations. the 203-GHz radiances can penetrate most ice clouds and are sensitive to ice crystals of convective origin. Rough ice water content (IWC) retrievals are made near the tropopause using estimated size distributions from in situ convective studies. The seasonal mean IWC observed at 100 hPa reaches vapor-equivalent 20 ppmv or more over convective centers, dominating the total water content. Convectively lofted ice, therefore, appears to be hydrologically significant at the tropical cold point. IWC is well correlated spatially with relative humidity with respect to ice (RH) at 100 hPa during both the dry (January-March) and moist (July-September) periods. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Univ Maryland, Earth Syst Sci Interdisciplinary Ctr, College Pk, MD USA. Yale Univ, Dept Geol & Geophys, New Haven, CT USA. CALTECH, Jet Propuls Lab, Pasadena, CA 91125 USA. RP Wu, DL (reprint author), CALTECH, Jet Prop Lab, MS 183-701,4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Dong.L.Wu@jpl.nasa.gov RI Sherwood, Steven/B-5673-2008; Wu, Dong/D-5375-2012; Dessler, Andrew/G-8852-2012 OI Sherwood, Steven/0000-0001-7420-8216; Dessler, Andrew/0000-0003-3939-4820 NR 36 TC 29 Z9 29 U1 0 U2 1 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 J9 J ATMOS SCI JI J. Atmos. Sci. PD FEB PY 2005 VL 62 IS 2 BP 518 EP 530 DI 10.1175/JAS-3382.1 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 897NP UT WOS:000227012200015 ER PT J AU Marshak, A Knyazikhin, Y Larsen, ML Wiscombe, WJ AF Marshak, A Knyazikhin, Y Larsen, ML Wiscombe, WJ TI Small-scale drop-size variability: Empirical models for drop-size-dependent clustering in clouds SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID FULLY-DEVELOPED TURBULENCE; FAST-FSSP MEASUREMENTS; FINE-STRUCTURE; DISTRIBUTIONS; FLUCTUATIONS; SCATTERING; SPECTRUM AB By analyzing aircraft measurements of individual drop sizes in clouds, it has been shown in a companion paper that the probability of finding a drop of radius r at a linear scale l decreases as l(D(r)), where 0 less than or equal to D(r) less than or equal to 1. This paper shows striking examples of the spatial distribution of large cloud drops using models that simulate the observed power laws. In contrast to currently used models that assume homogeneity and a Poisson distribution Of Cloud drops. these models illustrate strong drop Clustering, especially with larger drops. The degree of clustering is determined by the observed exponents D(r). The strong clustering of large drops arises naturally front the observed power-law statistics. This clustering has vital consequences for rain physics. including how fast rain can form. For radiative transfer theory. Clustering of large drops enhances their impact on the cloud optical path. The clustering phenomenon also helps explain why remotely sensed cloud drop size is generally larger than that measured in situ. C1 NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. Boston Univ, Dept Geog, Boston, MA 02215 USA. Michigan Technol Univ, Dept Phys, Houghton, MI 49931 USA. NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. RP Marshak, A (reprint author), NASA, Goddard Space Flight Ctr, Climate & Radiat Branch, Greenbelt, MD 20771 USA. EM Alexander.Marshak@nasa.gov RI Wiscombe, Warren/D-4665-2012; Marshak, Alexander/D-5671-2012 OI Wiscombe, Warren/0000-0001-6844-9849; NR 31 TC 13 Z9 13 U1 1 U2 3 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-4928 EI 1520-0469 J9 J ATMOS SCI JI J. Atmos. Sci. PD FEB PY 2005 VL 62 IS 2 BP 551 EP 558 DI 10.1175/JAS-3371.1 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 897NP UT WOS:000227012200018 ER PT J AU Wang, XH Wang, B Bos, PJ Anderson, JE Pouch, JJ Miranda, FA AF Wang, XH Wang, B Bos, PJ Anderson, JE Pouch, JJ Miranda, FA TI Finite-difference time-domain simulation of a liquid-crystal optical phased array SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID SPATIAL LIGHT-MODULATOR; BEAM-STEERING DEVICES; MAXWELLS EQUATIONS; FIELD AB Accurate modeling of a high-resolution, liquid-crystal-based, optical phased array (OPA) is demonstrated. The modeling method is extendable to cases where the array element size is close to the wavelength of light. This is accomplished through calculating an equilibrium liquid-crystal (LC) director field that takes into account the fringing electric fields in LC OPAs with small array elements and by calculating the light transmission with a finite-difference time-domain method that has been extended for use in birefringent materials. The diffraction efficiency for a test device is calculated and compared with the simulation. (C) 2005 Optical Society of America. C1 Kent State Univ, Inst Liquid Crystal, Kent, OH 44242 USA. Hana Microdisplay Technol Inc, Twinsburg, OH 44087 USA. NASA, John H Glenn Res Ctr, Cleveland, OH 44135 USA. RP Bos, PJ (reprint author), Kent State Univ, Inst Liquid Crystal, Kent, OH 44242 USA. EM pbos@kent.edu NR 26 TC 19 Z9 20 U1 1 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1084-7529 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD FEB PY 2005 VL 22 IS 2 BP 346 EP 354 DI 10.1364/JOSAA.22.000346 PG 9 WC Optics SC Optics GA 891ND UT WOS:000226586900018 PM 15717566 ER PT J AU Fomin, AE Gorodetsky, ML Grudinin, IS Ilchenko, VS AF Fomin, AE Gorodetsky, ML Grudinin, IS Ilchenko, VS TI Nonstationary nonlinear effects in optical microspheres SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID WHISPERING-GALLERY MODES; MICROCAVITY; SCATTERING AB Thermal nonlinearity can produce oscillatory instability in optical microspheres. We experimentally demonstrate this instability and analyze the conditions needed to observe this regime. The observed behavior is in good agreement with the results of numerical simulation. In pure fused silica with low optical absorption the thermal oscillations are suppressed owing to an interaction of thermal and Kerr nonlinearities. We also describe experimentally observed slow and irreversible thermo-optical processes in microspheres. (C) 2005 Optical Society of America. C1 Moscow MV Lomonosov State Univ, Fac Phys, Moscow 119992, Russia. CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Fomin, AE (reprint author), Moscow MV Lomonosov State Univ, Fac Phys, Moscow 119992, Russia. EM grudinin@caltech.edu RI Gorodetsky, Michael/C-5938-2008 OI Gorodetsky, Michael/0000-0002-5159-2742 NR 12 TC 60 Z9 61 U1 0 U2 13 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 FEB PY 2005 VL 22 IS 2 BP 459 EP 465 DI 10.1364/JOSAB.22.000459 PG 7 WC Optics SC Optics GA 896XM UT WOS:000226967800021 ER PT J AU Ciftcioglu, N Haddad, RS Golden, DC Morrison, DR McKay, DS AF Ciftcioglu, N Haddad, RS Golden, DC Morrison, DR McKay, DS TI A potential cause for kidney stone formation during space flights: Enhanced growth of nanobacteria in microgravity SO KIDNEY INTERNATIONAL LA English DT Article DE kidney stones; nanobacteria; microgravity ID SIMULATED MICROGRAVITY; CELL-CULTURES; BIOREACTOR; DISEASE; BLOOD; RISK AB Background. Although some information is available regarding the cellular/molecular changes in immune system exposed to microgravity, little is known about the reasons of the increase in the kidney stone formation in astronauts during and/or after long duration missions at zero gravity (0g). In our earlier studies, we have assessed a unique agent, nanobacteria (NB), in kidney stones and hypothesized that NB have an active role in calcium phosphate-carbonate deposition in kidney. In this research we studied effect of microgravity on multiplication and calcification of NB in vitro. Methods. We examined NB cultures in High Aspect Rotating Vessels (HARVs) designed at the NASA's Johnson Space Center, which are designed to stimulate some aspects of microgravity. Multiplication rate and calcium phosphate composition of those NB were compared with NB cultured on stationary and shaker flasks. Collected aliquots of the cultures from different incubation periods were analyzed using spectrophotometer, SEM, TEM, EDX, and x-ray diffraction techniques. Results. The results showed that NB multiplied 4.6x faster in HARVs compared to stationary cultures, and 3.2x faster than shaker flask conditions. X-ray diffraction and EDX analysis showed that the degree of apatite crystal formation and the properties of the apatite depend on the specific culture conditions used. Conclusion. We now report an increased multiplication rate of NB in microgravity-simulated conditions. Thus, NB infection may have a potential role in kidney stone formation in crew members during space flights. For further proof to this hypothesis, screening of the NB antigen and antibody level in flight crew before and after flight would be necessary. C1 NASA, Lyndon B Johnson Space Ctr, USRA, Houston, TX 77058 USA. Univ Space Res Assoc, Houston, TX USA. Hernandez Engn Inc, Houston, TX USA. RP Ciftcioglu, N (reprint author), NASA, Lyndon B Johnson Space Ctr, USRA, Mail Code SA13,2101 Nasa Rd 1, Houston, TX 77058 USA. EM nciftcio@ems.jsc.nasa.gov NR 41 TC 37 Z9 43 U1 2 U2 10 PU BLACKWELL PUBLISHING INC PI MALDEN PA 350 MAIN ST, MALDEN, MA 02148 USA SN 0085-2538 J9 KIDNEY INT JI Kidney Int. PD FEB PY 2005 VL 67 IS 2 BP 483 EP 491 DI 10.1111/j.1523-1755.2005.67105.x PG 9 WC Urology & Nephrology SC Urology & Nephrology GA 889CH UT WOS:000226420600010 PM 15673296 ER PT J AU Anastasi, RE Madaras, EI AF Anastasi, RE Madaras, EI TI Application of ultrasonic guided waves for aging wire insulation assessment SO MATERIALS EVALUATION LA English DT Article DE guided waves; wire insulation; cylindrical waveguide; ultrasonics ID FLEXURAL WAVES; DISPERSION; RODS AB Aging wiring has become a critical issue to the aircraft indutry due to recent aircra t incidents. The problem is that over time the insulation ore wire becomes brittle nod cracks. This exposes the underlying conductive wire, creating the potential for short circuits and fire. Popular methods of monitoring aging wire focus on applying electrical sensing techniques that are sensitive to the conductor's condition, but not very sensitive to the insulation's condition. Thus, the development of techniques to quantify and monitor aging noire insulation is highly warranted. Measurement of wire insulation stiffness by ultrasonic guided waves is being tested. Initial laboratory tests were per formed on a simple model consisting of a solid cylinder and a solid c cylinder with a polymer coating. Experimental measurements showed that lie lowest order extensional mode could be sensitive to stiffness changes in the wire insulation. To test this theory, conventional noire samples (typically found in aircraft) were heat damaged in an oven, in a range of heat no conditions. The samples were 12,16 mad 20 gage and the heat damage introduced material changes in the noire insulation that made the originally flexible insulation brittle and darker in color. Extensional mode phase velocity increased for the samples that were exposed to heat for a longer duration. Although the heat damage conditions may be more extreme than those encountered in environmental aging, indications are that this technique has the potential to detect and quantify degradation in wire insulation. C1 USA, Res Lab, Vehicle Technol Directorate, AMSRL VTS,Nondestruct Evaluat Sci Branch, Hampton, VA 23681 USA. NASA, Langley Res Ctr, Nondestruct Evaluat Sci Branch, Hampton, VA 23681 USA. RP Anastasi, RE (reprint author), USA, Res Lab, Vehicle Technol Directorate, AMSRL VTS,Nondestruct Evaluat Sci Branch, Hampton, VA 23681 USA. EM robert.f.anastasi@nasa.gov NR 12 TC 6 Z9 6 U1 0 U2 2 PU AMER SOC NONDESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD FEB PY 2005 VL 63 IS 2 BP 143 EP 147 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA 894AL UT WOS:000226762100004 ER PT J AU Bogard, DD Garrison, DH Takeda, H AF Bogard, DD Garrison, DH Takeda, H TI Ar-Ar and I-Xe ages and the thermal history of IAB meteorites SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID IRON-METEORITES; SILICATE INCLUSIONS; ACAPULCO METEORITE; PARENT BODY; PLAGIOCLASE-DIOPSIDE; SYSTEMATIC-ERRORS; PARTIAL MELT; IIE IRON; EVOLUTION; PETROLOGY AB Studies of several samples of the large Caddo County IAB iron meteorite reveal andesitic material enriched in Si, Na, Al, and Ca, which is essentially unique among meteorites. This material is believed to have formed from a chondritic source by partial melting and to have further segregated by grain coarsening. Such an origin implies extended metamorphism of the IAB parent body. New Ar-39-Ar-40 ages for silicate from three different Caddo samples are consistent with a common age of 4.50-4.51 Gyr. Less well-defined Ar-Ar degassing ages for inclusions from two other IABs, EET (Elephant Moraine) 83333 and Udei Station, are &SIM; 4.32 Gyr, whereas the age for Campo del Cielo varies considerably over about 3.23-4.56 Gyr. New I-129-Xe-119 ages for Caddo County and EET 83333 are 4557.9 &PLUSMN; 0.1 Myr and 4557-4560 Myr, respectively, relative to an age of 4562.3 Myr for Shallowater. Considering all reported Ar-Ar degassing ages for IABs and related winonaites, the range is &SIM; 4.32-4.53 Gyr, but several IABs give similar Ar ages of 4.50-4.52 Gyr. We interpret these older Ar ages to represent cooling after the time of last significant metamorphism on the parent body and the younger ages to represent later Ar-40 diffusion loss. The older Ar-Ar ages for IABs are similar to Sm-Nd and Rb-Sr isochron ages reported in the literature for Caddo County. Considering the possibility that IAB parent body formation was followed by impact disruption, reassembly, and metamorphism (e.g., Benedix et al. 2000), the Ar-Ar ages and IAB cooling rates deduced from Ni concentration profiles in IAB metal (Herpfer et al. 1994) are consistent if the time of the post-assembly metamorphism was as late as about 4.53 Gyr ago. However, I-Xe ages reported for some IABs define much older ages of about 4558-4566 Myr, which cannot easily be reconciled with the much younger Ar-Ar and Sm-Nd ages. An explanation for the difference in radiometric ages of IABs may reside in combinations of the following: a) I-Xe ages have very high closure temperatures and were not reset during metamorphism about 4.53 Gyr ago; b) a bias exists in the K-40 decay constants which makes these Ar-Ar ages approximately 30 Myr too young; c) the reported Sm-Nd and Rb-Sr ages for Caddo are in error by amounts equal to or exceeding their reported 2-sigma uncertainties; and d) about 30 Myr after the initial heating that produced differentiation of Caddo silicate and mixing of silicate and metal, a mild metamorphism of the IAB parent body reset the Ar-Ar ages. C1 NASA, Lyndon B Johnson Space Ctr, ARES, Houston, TX 77058 USA. ESCG Barrios Technol, Houston, TX 77058 USA. Chiba Inst Technol, Res Inst, Narashino, Chiba 2750016, Japan. RP Bogard, DD (reprint author), NASA, Lyndon B Johnson Space Ctr, ARES, Code KR,2101 NASA Pkwy, Houston, TX 77058 USA. EM donald.d.bogard@nasa.gov NR 54 TC 26 Z9 26 U1 1 U2 2 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD FEB PY 2005 VL 40 IS 2 BP 207 EP 224 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 924GW UT WOS:000228968000005 ER PT J AU Ruzicka, A Killgore, M Mittlefehldt, DW Fries, MD AF Ruzicka, A Killgore, M Mittlefehldt, DW Fries, MD TI Portales valley: Petrology of a metallic-melt meteorite breccia SO METEORITICS & PLANETARY SCIENCE LA English DT Review ID LL-GROUP CHONDRITES; RARE-EARTH ELEMENTS; NI-S SYSTEM; IRON-METEORITES; PARENT BODY; SIDEROPHILE ELEMENTS; SHOCK METAMORPHISM; LIQUID; PLAGIOCLASE; OXIDATION AB Portales Valley (PV) is an unusual metal-veined meteorite that has been classified as an H6 chondrite. It has been regarded either as an annealed impact melt breccia, as a primitive achondrite, or as a meteorite with affinities to silicated iron meteorites. We studied the petrology of PV using a variety of geochemical-mineralogical techniques. Our results suggest that PV is the first well-documented metallic-melt meteorite breccia. Mineral-chemical and other data suggest that the protolith to PV was an H chondrite. The composition of FeNi metal in PV is somewhat fractionated compared to H chondrites and varies between coarse vein and silicate-rich portions. It is best modeled as having formed by partial melting at temperatures of &SIM; 940-1150 &DEG; C, with incomplete separation of solid from liquid metal. Solid metal concentrated in the coarse vein areas and S-bearing liquid metal concentrated in the silicate-rich areas, possibly as a result of a surface energy effect. Both carbon and phosphorus must have been scavenged from large volumes and concentrated in metallic liquid. Graphite nodules formed by crystallization from this liquid, whereas phosphate formed by reaction between P-bearing metal and clinopyroxene components, depleting clinopyroxene throughout much of the meteorite and growing coarse phosphate at metal-silicate interfaces. Some phosphate probably crystallized from P-bearing liquids, but most probably formed by solid-state reaction at &SIM; 975-725 &DEG; C. Phosphate-forming and FeO-reduction reactions were widespread in PV and entailed a change in the mineralogy of the stony portion on a large scale. Portales Valley experienced protracted annealing from supersolidus to subsolidus temperatures, probably by cooling at depth within its parent body, but the main differences between PV and H chondrites arose because maximum temperatures were higher in PV A combination of a relatively weak shock event and elevated pre-shock temperatures probably produced the vein-and-breccia texture, with endogenic heating being the main heat source for melting, and with stress waves from an impact event being an essential trigger for mobilizing metal. Portales Valley is best classified as an H7 metallic-melt breccia of shock stage S1. The meteorite is transitional between more primitive (chondritic) and evolved (achondrite, iron) meteorite types and offers clues as to how differentiation could have occurred in some asteroidal bodies. C1 Portland State Univ, Cascadia Meteorite Lab, Dept Geol, Portland, OR 97207 USA. SW Meteorite Lab, Payson, AZ 85547 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA. RP Ruzicka, A (reprint author), Portland State Univ, Cascadia Meteorite Lab, Dept Geol, 17 Cramer Hall,1721 SW Broadway,POB 751, Portland, OR 97207 USA. EM ruzickaa@pdx.edu RI Facility, NENIMF/B-8811-2015 NR 103 TC 33 Z9 33 U1 0 U2 4 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 USA SN 1086-9379 J9 METEORIT PLANET SCI JI Meteorit. Planet. Sci. PD FEB PY 2005 VL 40 IS 2 BP 261 EP 295 PG 35 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 924GW UT WOS:000228968000009 ER PT J AU Davis, JA Greenhall, CA Stacey, PW AF Davis, JA Greenhall, CA Stacey, PW TI A Kalman filter clock algorithm for use in the presence of flicker frequency modulation noise SO METROLOGIA LA English DT Article ID TIMESCALES; GENERATOR; MODELS AB The National Physical Laboratory (NPL) has developed a Kalman filter based algorithm for combining measurements from its three active hydrogen masers. The algorithm is designed to produce a near optimal composite clock when the dominant noise process of at least one of the masers is flicker frequency modulation (FFM), and significant linear frequency drift is exhibited. The FFM is modelled approximately by a linear combination of Markov noise processes. Each Markov process is included in the Kalman filter and contributes an additional component to the state vector. Both the validity of the model and the effectiveness of adding these additional components are examined. The performance of the new algorithm is investigated when applied to simulated measurements and also to measurements obtained from NPL's hydrogen masers. C1 Natl Phys Lab, Teddington TW11 0LW, Middx, England. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Davis, JA (reprint author), Natl Phys Lab, Hampton Rd, Teddington TW11 0LW, Middx, England. NR 16 TC 25 Z9 26 U1 0 U2 2 PU BUREAU INT POIDS MESURES PI SEVRES CEDEX PA B1 PM PAVILLION DE BRETUEIL, F-92312 SEVRES CEDEX, FRANCE SN 0026-1394 J9 METROLOGIA JI Metrologia PD FEB PY 2005 VL 42 IS 1 BP 1 EP 10 DI 10.1088/0026-1394/42/1/001 PG 10 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 915HL UT WOS:000228288800005 ER PT J AU Wadaa, A Olariu, S Wilson, L Eltoweissy, M Jones, K AF Wadaa, A Olariu, S Wilson, L Eltoweissy, M Jones, K TI Training a wireless sensor network SO MOBILE NETWORKS & APPLICATIONS LA English DT Article DE wireless sensor networks; self-organization; dynamic coordinate system; training; clustering; security; energy-efficient protocols ID RADIO NETWORKS; PROTOCOLS AB The networks considered in this paper consist of tiny energy-constrained commodity sensors massively deployed, along with one or more sink nodes providing interface to the outside world. Our contribution is to propose a scalable energy-efficient training protocol for nodes that are initially anonymous, asynchronous and unaware of their location. Our training protocol imposes a flexible and intuitive coordinate system onto the deployment area and partitions the anonymous nodes into clusters where data can be gathered from the environment and synthesized under local control. An important by-product of the training protocol is a simple and natural data fusion protocol as well as an energy-efficient protocol for routing data from clusters to the sink node. Being energy-efficient, our training protocol can be run on either a scheduled or ad-hoc basis to provide robustness and dynamic reconfiguration. We also outline a way of making the training protocol secure by using a parameterized variant of frequency hopping. C1 Old Dominion Univ, Dept Comp Sci, Norfolk, VA 23529 USA. Virginia Tech, Dept Comp Sci, Falls Church, VA 22043 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. RP Old Dominion Univ, Dept Comp Sci, Norfolk, VA 23529 USA. EM wadaa@cs.odu.edu; olariu@cs.odu.edu; wilson@cs.odu.edu; toweissy@vt.edu; k.h.jones@nasa.gov NR 42 TC 55 Z9 60 U1 0 U2 3 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 1383-469X EI 1572-8153 J9 MOBILE NETW APPL JI Mobile Netw. Appl. PD FEB-APR PY 2005 VL 10 IS 1-2 BP 151 EP 168 DI 10.1023/B:MONE.0000048552.15853.c2 PG 18 WC Computer Science, Hardware & Architecture; Computer Science, Information Systems; Telecommunications SC Computer Science; Telecommunications GA 872DA UT WOS:000225185500012 ER PT J AU Barnes, JR Cameron, AC Lister, TA Pointer, GR Still, MD AF Barnes, JR Cameron, AC Lister, TA Pointer, GR Still, MD TI LO Peg in 1998: star-spot patterns and differential rotation SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE line : profiles; methods : data analysis; stars : activity; stars : atmospheres; stars : individual : LO Peg (BD+22 4409); stars : late-type ID MAIN-SEQUENCE STARS; DUAL-SITE OBSERVATIONS; G-DWARFS; DOPPLER IMAGES; ACTIVE STARS; AB DORADUS; COOL STARS; BD+22-DEGREES-4409; EVOLUTION; YOUNG AB We present Doppler images of the young K5V-K7V rapid rotator LO Peg from seven nights of continuous spectroscopy obtained in 1998 from July 04 to July 10. The images reveal the presence of a strong polar cap with appendages extending to mid-latitudes, but no star-spots are seen below 15degrees. We briefly discuss the distribution of spots in light of recent flux transport simulations, which are able to reproduce the observed latitude dependence. With the full time series of spectra, of which 314 are useful, many phases are observed three times over the seven nights of observations. Using star-spots as tracers of a solar-like latitudinal differential rotation in our image reconstructions, we find that the equatorial regions complete one more rotation than the polar regions every 181 +/- 35 d. LO Peg is the second coolest star for which such a measurement has been made using indirect imaging methods. The degree of latitudinal shear is less than that seen in G and early K dwarfs, suggesting a trend in which differential rotation decreases with stellar mass in (pre-)main-sequence objects. C1 Univ St Andrews, Sch Phys & Astron, St Andrews KY16 9SS, Fife, Scotland. NASA, Goddard Space Flight Ctr, Univ Space Res Assoc, Greenbelt, MD 20771 USA. RP Barnes, JR (reprint author), Univ St Andrews, Sch Phys & Astron, St Andrews KY16 9SS, Fife, Scotland. EM jrb3@st-andrews.ac.uk OI Cameron, Andrew/0000-0002-8863-7828 NR 38 TC 20 Z9 20 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 FEB 1 PY 2005 VL 356 IS 4 BP 1501 EP 1508 DI 10.1111/j.1365-2966.2004.08588.x PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 889DG UT WOS:000226423100027 ER PT J AU Rodgers, SD Charnley, SB AF Rodgers, SD Charnley, SB TI Suprathermal chemical reactions driven by fast hydrogen atoms in cometary comae SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE astrochemistry; molecular processes; comets : general ID C1 IKEYA-ZHANG; PLANETARY-ATMOSPHERES; HYDROXYL RADICALS; 157 NM; METHANOL; PHOTODISSOCIATION; WATER; H2O; HNC; PHOTOLYSIS AB We have investigated the role that energetic hydrogen atoms, produced in cometary comae by the photodissociation of water molecules, could have in driving chemical reactions that are endothermic, or possess activation energy barriers. We have developed a model of the density and energy spectrum of these atoms in the coma and have incorporated a number of reactions driven by fast H atoms into our existing coma model. We find that, in high-activity comets close to the Sun, such reactions are competitive with direct photodissociation as the principal destruction mechanism for molecules with long lifetimes in the solar radiation field. We show that measurements of the CH2OH : CH3O ratio may be used to assess the importance of suprathermal reactions in the coma. We also confirm that these reactions are probably unable to account for the observed HNC: HCN ratios. C1 NASA, Ames Res Ctr, Div Space Sci, Moffett Field, CA 94035 USA. RP Rodgers, SD (reprint author), NASA, Ames Res Ctr, Div Space Sci, MS 245-3, Moffett Field, CA 94035 USA. EM rodgers@dusty.arc.nasa.gov RI Charnley, Steven/C-9538-2012 NR 37 TC 11 Z9 11 U1 0 U2 3 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 FEB 1 PY 2005 VL 356 IS 4 BP 1542 EP 1548 DI 10.1111/j.1365-2966.2004.08606.x PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 889DG UT WOS:000226423100031 ER PT J AU Keenan, FP Aggarwal, KM Milligan, RO Ryans, RSI Bloomfield, DS Srigengan, V O'Mullane, MG Lawson, KD Msezane, AZ Brosius, JW Davila, JM Thomas, RJ AF Keenan, FP Aggarwal, KM Milligan, RO Ryans, RSI Bloomfield, DS Srigengan, V O'Mullane, MG Lawson, KD Msezane, AZ Brosius, JW Davila, JM Thomas, RJ TI Emission lines of Fe XV in spectra obtained with the Solar Extreme-Ultraviolet Research Telescope and Spectrograph SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE atomic data; Sun : activity; Sun : flares; ultraviolet : general ID MG-LIKE IONS; ACTIVE-REGION; ATOMIC DATABASE; EXTENDED ANALYSIS; OPTICALLY THIN; TRANSITIONS; SERTS; CHIANTI; IDENTIFICATION; EXCITATION AB Recent R-matrix calculations of electron impact excitation rates in Mg-like Fe XV are used to derive theoretical emission-line ratios involving transitions in the 243-418 Angstrom wavelength range. A comparison of these with a data set of solar active region, subflare and off-limb spectra, obtained during rocket flights by the Solar Extreme-Ultraviolet Research Telescope and Spectrograph (SERTS), reveals generally very good agreement between theory and observation, indicating that most of the Fe XV emission lines may be employed with confidence as electron density diagnostics. In particular, the 312.55-Angstrom line of Fe XV is not significantly blended with a CoXVII transition in active region spectra, as suggested previously, although the latter does make a major contribution in the subflare observations. Most of the Fe XV transitions which are blended have had the species responsible clearly identified, although there remain a few instances where this has not been possible. We briefly address the long-standing discrepancy between theory and experiment for the intensity ratio of the 3s(21) S-3s3p P-3(1) intercombination line at 417.25 Angstrom to the 3s(21) S-3s3p P-1 resonance transition at 284.16 Angstrom. C1 Queens Univ Belfast, Dept Phys & Astron, Belfast BT7 1NN, Antrim, North Ireland. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. UKAEA Euratom Fus Assoc, Culham Sci Ctr, Abingdon OX14 3DB, Oxon, England. Clark Atlanta Univ, Ctr Theoret Studies Phys Syst, Atlanta, GA 30304 USA. Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. RP Keenan, FP (reprint author), Queens Univ Belfast, Dept Phys & Astron, Belfast BT7 1NN, Antrim, North Ireland. EM E.Keenan@qub.ac.uk RI Bloomfield, Shaun/G-5809-2011 OI Bloomfield, Shaun/0000-0002-4183-9895 NR 31 TC 5 Z9 5 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 FEB 1 PY 2005 VL 356 IS 4 BP 1592 EP 1598 DI 10.1111/j.1365-2966.2005.08637.x PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 889DG UT WOS:000226423100037 ER PT J AU Bryson, S Kosovichev, A Levy, D AF Bryson, S Kosovichev, A Levy, D TI High-order shock-capturing methods for modeling dynamics of the solar atmosphere SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article DE coronal oscillations; spicules; rebound-shock models; high-order central-upwind schemes; balance laws; conservation laws; source terms ID HYPERBOLIC CONSERVATION-LAWS; SPICULES; SCHEMES AB We use one-dimensional high-order central shock-capturing numerical methods to study the response of various model solar atmospheres to forcing at the solar surface. The dynamics of the atmosphere is modeled with the Euler equations in a variable-sized flux tube in the presence of gravity. We study dynamics of the atmosphere suggestive of spicule formation and coronal oscillations. These studies are performed on observationally derived model atmospheres above the quiet sun and above sunspots. To perform these simulations, we provide a new extension of existing second- and third-order shock-capturing methods to irregular grids. We also solve the problem of numerically maintaining initial hydrostatic balance via the introduction of new variables in the model equations and a careful initialization mechanism. We find several striking results: all model atmospheres respond to a single impulsive perturbation with several strong shock waves consistent with the rebound-shock model. These shock waves lift material and the transition region well into the initial corona, and the sensitivity of this lift to the initial impulse depends nonlinearly on the details of the atmosphere model. We also reproduce an observed 3 min coronal oscillation above sunspots as well as 5 min oscillations above the quiet sun. (C) 2004 Elsevier B.V. All rights reserved. C1 Stanford Univ, Dept Math, Stanford, CA 94305 USA. Stanford Univ Hosp, WW Hansen Expt Phys Lab, Stanford, CA 94305 USA. NASA, Ames Res Ctr, Adv Supercomp Div, Moffett Field, CA 94035 USA. Stanford Univ, Program Sci Comp Computat Math, Moffett Field, CA 94035 USA. RP Levy, D (reprint author), Stanford Univ, Dept Math, Stanford, CA 94305 USA. EM bryson@nas.nasa.gov; sasha@quake.stanford.edu; dlevy@math.stanford.edu NR 17 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD FEB 1 PY 2005 VL 201 IS 1-2 BP 1 EP 26 DI 10.1016/j.physd.2004.12.006 PG 26 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 900GP UT WOS:000227203700001 ER PT J AU Hahne, GE AF Hahne, GE TI Comment on "Quantum tunneling time" SO PHYSICAL REVIEW A LA English DT Letter AB In this Comment on the paper by Wang [Phys. Rev. A 69, 052108 (2004)], it is pointed out that (i) a group-theoretical argument advanced in the first part of their derivation is both flawed and not needed in what follows, (ii) they then assert a formula that leads to a physically incorrect phase (as distinguished from group) delay time in the motion of a free particle, and (iii) their subsequent derivation contains a mathematical error, such that the outcome is a new formula for the tunneling time that avoids the second problem, but such that the result is unfounded and is therefore of unknown physical content. C1 NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. RP Hahne, GE (reprint author), NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. EM hahne@nas.nasa.gov NR 2 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 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB PY 2005 VL 71 IS 2 AR 026101 DI 10.1103/PhysRevA.71.026101 PG 2 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 904GK UT WOS:000227483900128 ER PT J AU Abazajian, K Switzer, ER Dodelson, S Heitmann, K Habib, S AF Abazajian, K Switzer, ER Dodelson, S Heitmann, K Habib, S TI Nonlinear cosmological matter power spectrum with massive neutrinos: The halo model SO PHYSICAL REVIEW D LA English DT Article ID LARGE-SCALE STRUCTURE; GALAXY; PARAMETERS; OSCILLATIONS; CONSTRAINTS; EVOLUTION; UNIVERSE; BIAS AB Measurements of the linear power spectrum of galaxies have placed tight constraints on neutrino masses. We extend the framework of the halo model of cosmological nonlinear matter clustering to include the effect of massive neutrino infall into cold dark matter (CDM) halos. The magnitude of the effect of neutrino clustering for three degenerate mass neutrinos with m(nui)=0.9 eV is of order similar to1%, within the potential sensitivity of upcoming weak lensing surveys. In order to use these measurements to further constrain-or eventually detect-neutrino masses, accurate theoretical predictions of the nonlinear power spectrum in the presence of massive neutrinos will be needed, likely only possible through high-resolution multiple particle (neutrino, CDM and baryon) simulations. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Los Alamos Natl Lab, ISR Div, Los Alamos, NM 87545 USA. RP Abazajian, K (reprint author), Los Alamos Natl Lab, Div Theoret, MS B285, Los Alamos, NM 87545 USA. NR 40 TC 40 Z9 40 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD FEB PY 2005 VL 71 IS 4 AR 043507 DI 10.1103/PhysRevD.71.043507 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 901ZC UT WOS:000227319800016 ER PT J AU Estabrook, FB AF Estabrook, FB TI Mathematical structure of tetrad equations for vacuum relativity SO PHYSICAL REVIEW D LA English DT Article ID SPECIAL ORTHONORMAL FRAMES; GEOMETRIES; FORM AB The tetrad partial differential equations formulated by Buchman and Bardeen for vacuum gravity are shown to be well posed by calculation of the Cartan characters of an associated exterior differential system. Gauge specializations are discussed. A Cartan 4-form is found for this field theory, together with its intrinsic version the Lagrangian density. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Estabrook, FB (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 21 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD FEB PY 2005 VL 71 IS 4 AR 044004 DI 10.1103/PhysRevD.71.044004 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 901ZC UT WOS:000227319800033 ER PT J AU Tinto, M Vallisneri, M Armstrong, JW AF Tinto, M Vallisneri, M Armstrong, JW TI Time-delay interferometric ranging for space-borne gravitational-wave detectors SO PHYSICAL REVIEW D LA English DT Article AB Space-borne interferometric gravitational-wave detectors, sensitive in the low-frequency (mHz) band, will fly in the next decade. In these detectors, the spacecraft-to-spacecraft light-travel times will necessarily be unequal and time varying, and (because of aberration) will have different values on up- and down-links. In such unequal-armlength interferometers, laser-phase noise will be canceled by taking linear combinations of the laser-phase observables measured between pairs of spacecraft, appropriately time shifted by the light propagation times along the corresponding arms. This procedure, known as time-delay interferometry (TDI), requires an accurate knowledge of the light-time delays as functions of time. Here we propose a high-accuracy technique to estimate these time delays, and we study its use in the context of the Laser Interferometer Space Antenna (LISA) mission. We refer to this ranging technique, which relies on the TDI combinations themselves, as time-delay interferometric ranging (TDIR). For every TDI combination, we show that, by minimizing the rms power in that combination (averaged over integration times similar to10(4) s) with respect to the time-delay parameters, we obtain estimates of the time delays accurate enough to cancel laser noise to a level well below the secondary noises. Thus TDIR allows the implementation of TDI without the use of dedicated interspacecraft ranging systems, with a potential simplification of the LISA design. In this paper we define the TDIR procedure formally, and we characterize its expected performance via simulations with the Synthetic LISA software package. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. RP CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Massimo.Tinto@jpl.nasa.gov; Michele.Vallisneri@jpl.nasa.gov; John.W.Armstrong@jpl.nasa.gov NR 14 TC 14 Z9 14 U1 0 U2 0 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 FEB PY 2005 VL 71 IS 4 AR 041101 DI 10.1103/PhysRevD.71.041101 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 901ZC UT WOS:000227319800001 ER PT J AU Kletetschka, G Ness, NF Connerney, JEP Acuna, MH Wasilewski, PJ AF Kletetschka, G Ness, NF Connerney, JEP Acuna, MH Wasilewski, PJ TI Grain size dependent potential for self generation of magnetic anomalies on Mars via thermoremanent magnetic acquisition and magnetic interaction of hematite and magnetite SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article DE magnetic mineralogy; self-magnetization; blocking temperature; Martian crust; temperature gradient ID REMANENT MAGNETIZATION; MULTIDOMAIN GRAINS; LAMELLAR MAGNETISM; SNC METEORITES; IGNEOUS ROCKS; FIELD; PYRRHOTITE; TRM; SPECTROMETER; TEMPERATURE AB Early in the history of planetary evolution portions of Martian crust became magnetized by dynamo-generated magnetic field. A lateral distribution of the secondary magnetic field generated by crustal remanent sources containing magnetic carriers of certain gram size and mineralogy is able to produce an ambient magnetic field of larger intensity than preexisting dynamo. This ambient field is capable of magnetizing portions of deeper crust that cools through its blocking temperatures in an absence of dynamo. We consider both magnetite (Fe3O4) and hematite (alpha-Fe2O3) as minerals contributing to the overall magnetization. Analysis of magnetization of magnetic minerals of various grain size and concentration reveals that magnetite grains less than 0.01 nun in size, and hematite grains larger than 0.01 mm in size can become effective magnetic source capable of magnetizing magnetic minerals contained in surrounding volume. Preexisting crustal remanence (for example similar to250 A/m relates to 25% of multi-domain hematite) can trigger a self-magnetizing process that can continue in the absence of magnetic dynamo and continue strengthening and/or weakening magnetic anomalies on Mars. Thickness of the primary magnetic layer and concentration of magnetic carriers allow specification of the temperature gradient required to trigger a self-magnetization process. (C) 2004 Elsevier B.V. All rights reserved. C1 Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. Acad Sci Czech Republ, Inst Geol, Prague, Czech Republic. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. RP Kletetschka, G (reprint author), Catholic Univ Amer, Dept Phys, Washington, DC 20064 USA. EM gunther.kletetsckka@gsfc.nasa.gov RI Kletetschka, Gunther/C-9996-2011; connerney, john/I-5127-2013 OI Kletetschka, Gunther/0000-0002-0645-9037; NR 44 TC 15 Z9 15 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD FEB PY 2005 VL 148 IS 2-4 BP 149 EP 156 DI 10.1016/j.pepi.2004.08.010 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 898XL UT WOS:000227109400003 ER PT J AU Kenny, A Palazzolo, A Preuss, J Tucker, R Konno, K AF Kenny, A Palazzolo, A Preuss, J Tucker, R Konno, K TI Electropolishing iron-cobalt-vanadium laminate stacks to improve performance of electrical machinery SO PLATING AND SURFACE FINISHING LA English DT Article AB An electropolishing method was developed for electrical machinery laminated stacks of a 49% Fe, 49% Co, 2% V alloy. The method removed the metal most rapidly at the laminate interfaces. The glue between the laminates was washed away as the metal was removed. A mixture consisting of phosphoric and hydroxyacetic acids and ethylene glycol produce an unpitted polished surface. The electropolishing technique was especially effective at removing metal on the laminated stack surface that caused electrical shorting of the laminates. C1 Texas A&M Univ, Dept Mech Engn, College Stn, TX 77840 USA. Texas A&M Univ, Vibrat Control & Electromech Lab, College Stn, TX 77840 USA. NASA, Gleann Res Ctr, Turbomachinery Branch, Cleveland, OH USA. RP Kenny, A (reprint author), Texas A&M Univ, Dept Mech Engn, College Stn, TX 77840 USA. EM a-kenny@neo.tamu.edu NR 5 TC 0 Z9 0 U1 0 U2 4 PU AMER ELECTROPLATERS SOC INC PI ORLANDO PA 12644 RESEARCH PKWY, ORLANDO, FL 32826-3298 USA SN 0360-3164 J9 PLAT SURF FINISH JI Plat. Surf. Finish. PD FEB PY 2005 VL 92 IS 2 BP 38 EP 41 PG 4 WC Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films SC Metallurgy & Metallurgical Engineering; Materials Science GA 898ZF UT WOS:000227114000007 ER PT J AU Williams, MK Weiser, ES Fesmire, JE Grimsley, BW Smith, TM Brenner, JR Nelson, GL AF Williams, MK Weiser, ES Fesmire, JE Grimsley, BW Smith, TM Brenner, JR Nelson, GL TI Effects of cell structure and density on the properties of high performance polyimide foams SO POLYMERS FOR ADVANCED TECHNOLOGIES LA English DT Article; Proceedings Paper CT 7th International Symposium on Polymers for Advanced Technologies CY SEP 21-24, 2003 CL Ft Lauderdale, FL DE polyimides; foams; thermal properties; mechanical properties; high performance polymers ID FIRE AB Activity at the NASA Langley Research Center (LaRC) has focused on developing low density polyimide foam and foam structures which are made using monomeric solutions or salt solutions formed from the reaction of a dianhydride and diamine dissolved in a mixture of foaming agents and alkyl alcohol at room temperature. Monomer blends may be used to make a variety of polyimide foams with varying properties. The first foaming process developed consisted of thermal cycling the polymer precursor residuum and allowing the inflation of the particles to interact to create the foam. This process has resulted in foam structures with higher percentages of open cell content. Another innovative foaming process has been developed that begins with partially inflated microspheres, "friable balloons", with incomplete polymer molecular weight gain, which when fully cured into a foam results in more closed cell structures. In a research study performed by NASA Kennedy Space Center (KSC) and LaRC, two closely related polyimide foams, TEEK-H series and TEEK-L series, (4,4'-oxydiphthalic anhydride/3,4-oxydianiline and 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride/4,4-oxydianiline) were investigated for density effects and closed versus open cell effects on the thermal, mechanical, and flammability properties. Thermal conductivity data under the full range of vacuum pressures indicate that these materials are effective insulators under cryogenic conditions. Contributing factors such as cell content, density, and surface area were studied to determine the effects on thermal conductivity. Cone calorimetry data indicated decreased peak heat release rates for the closed cell system, TEEK-H friable balloons, compared to the TEEK foams with higher open cell content. Mechanical properties including tensile strength and compressive strength indicated that the materials have good structural integrity. Foams with more open cell content resulted in greater tensile and compressive strengths than the closed cell foams. The maximum closed cell content achieved in the "friable balloon" system was 3 78% at a foam density of 0.048 gm/cm(3). Published in 2005 by John Wiley I Sons, Ltd. C1 NASA, Spaceport Engn & Technol, Testbed Technol Branch, Kennedy Space Ctr, FL 32899 USA. NASA, Langley Res Ctr, Hampton, VA 23681 USA. Florida Inst Technol, Melbourne, FL 32901 USA. RP Williams, MK (reprint author), NASA, Spaceport Engn & Technol, Testbed Technol Branch, YA-C2-T, Kennedy Space Ctr, FL 32899 USA. EM Martha.K.Williams@nasa.gov NR 21 TC 36 Z9 42 U1 10 U2 27 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1042-7147 J9 POLYM ADVAN TECHNOL JI Polym. Adv. Technol. PD FEB-MAR PY 2005 VL 16 IS 2-3 SI SI BP 167 EP 174 DI 10.1002/pat.567 PG 8 WC Polymer Science SC Polymer Science GA 907PQ UT WOS:000227730700016 ER PT J AU Lee, JM Pak, CG Lee, HS Choi, HG AF Lee, JM Pak, CG Lee, HS Choi, HG TI Vibration analysis of an idealized vertical pump model SO PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE LA English DT Article DE vertical pump; vibration resonance; Euler-Bernoulli beam; flexible foundation ID BEAM; MASS AB Vertical pumps have intrinsically weak structures for vibration resonance because of their long slender shapes. Therefore, it is important to estimate the vibration characteristics of a vertical pump analytically and/or experimentally before its final installation. Sometimes, however, unexpected resonances arise after the installation. The unexpected resonance is found to be due to the difference between the boundary condition of a vertical pump for rigid-foundation test operation and for flexible-foundation real operation. In order to examine this problem and quantify the effect of the foundation condition on the natural frequencies and mode shapes of the entire pump assembly, a mathematical model using a Euler-Bernoulli beam with a flexible foundation is presented. This model combines the lower and upper parts of a vertical pump, distinguishing it from previous analytical models. Experiments and simulations have been performed to validate this mathematical model and to evaluate the effect of foundation stiffness on vibration behaviour. Parametric studies have also been carried out to investigate the effects of other design variables on the dynamic characteristics of the pumps and to propose design strategies for improvement in the dynamics. C1 Seoul Natl Univ, Sch Mech & Aerosp Engn, Seoul 151742, South Korea. NASA, Dryden Flught Res Ctr, Edwards AFB, CA USA. Samsung Elect Co Ltd, Semicond Business, Suwon, Gyeonggi, South Korea. RP Lee, JM (reprint author), Seoul Natl Univ, Sch Mech & Aerosp Engn, San 56-1, Seoul 151742, South Korea. NR 10 TC 0 Z9 0 U1 0 U2 0 PU PROFESSIONAL ENGINEERING PUBLISHING LTD PI BURY ST EDMUNDS PA NORTHGATE AVENUE, BURY ST EDMUNDS IP32 6BW, SUFFOLK, ENGLAND SN 0954-4062 J9 P I MECH ENG C-J MEC JI Proc. Inst. Mech. Eng. Part C-J. Eng. Mech. Eng. Sci. PD FEB PY 2005 VL 219 IS 2 BP 169 EP 181 DI 10.1243/095440605X8423 PG 13 WC Engineering, Mechanical SC Engineering GA 923IP UT WOS:000228903900004 ER PT J AU Jackson, DJ Hockney, GM AF Jackson, Deborah J. Hockney, George M. TI Securing QKD links in the full Hilbert space SO QUANTUM INFORMATION PROCESSING LA English DT Article DE quantum key distribution; polarization state; temporal state; quantum cryptography ID PRACTICAL QUANTUM CRYPTOGRAPHY; OPTICAL-FIBER; POLARIZED PHOTONS; INTERFEROMETER; STATES; TIME; INTERFERENCE AB Many quantum key distribution QKD analyses examine the link security in a subset of the full Hilbert space that is available to describe the system. In reality; information about the photon state can be embedded in correlations between the polarization space and other dimensions of the full Hilbert space in such a way that Eve can determine the polarization of a photon without affecting it. This paper uses the concept of suitability Hockney et al. "Suitability versus Fidelity for Rating Single Photon Guns" to quantify the available information for Eve to exploit, and demonstrate how it is possible for Alice and Bob to fool themselves into thinking they have a highly secure link. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jackson, DJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Deborah.J.Jackson@jpl.nasa.gov NR 30 TC 3 Z9 3 U1 1 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1570-0755 EI 1573-1332 J9 QUANTUM INF PROCESS JI Quantum Inf. Process. PD FEB PY 2005 VL 4 IS 1 BP 35 EP 47 DI 10.1007/s11128-005-3194-5 PG 13 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 098MB UT WOS:000241523600003 ER PT J AU Fincke, EM Padalka, G Lee, D van Holsbeeck, M Sargsyan, AE Hamilton, DR Martin, D Melton, SL McFarlin, K Dulchavsky, SA AF Fincke, EM Padalka, G Lee, D van Holsbeeck, M Sargsyan, AE Hamilton, DR Martin, D Melton, SL McFarlin, K Dulchavsky, SA TI Evaluation of shoulder integrity in space: First report of musculoskeletal US on the International Space Station SO RADIOLOGY LA English DT Article ID FOCUSED ASSESSMENT; TRAUMA FAST; SONOGRAPHY; MEDICINE AB Investigative procedures were approved by Henry Ford, Human Investigation Committee and NASA Johnson Space Center Committee for Protection of Human Subjects. Informed consent was obtained. Authors evaluated ability of nonphysician crewmember to obtains diagnostic-quality musculoskeletal ultrasonographic (US) - data of the shoulder by following a just-in-time, training algorithm and using real-time remote guidance aboard the International, Space Station (ISS). ISS Expedition-9, crewmembers attended a 2.5-hour didactic and hands-66 US training session 4 months before launch. Aboard the ISS, they completed. a 1-hour computer-based Onboard Proficiency Enhancement program 7 days, before examination. Crewmembers did. not receive specific training in shoulder anatomy or shoulder US techniques Evaluation of astronaut shoulder integrity was done by using a Human Research Facility US system. Crew used special positioning techniques for subject and operator to facilitate US in microgravity environment. Common anatomic reference points aided initial probe,placement. Real-time US video of shoulder was transmitted to remote experienced sonologists in Telescience Center at Johnson Space Center. Probe manipulation and equipment adjustments were guided with verbal commands from remote sonologists to astronaut operators to complete rotator cuff evaluation. Comprehensive US of crewmember's shoulder included transverse and longitudinal images of biceps and supraspinatus. tendons and articular cartilage surface. Total. examination time required to guide astronaut operator to acquire necessary images was approximately 15 minutes. Multiple arm and probe positions were used to acquire dynamic video images that were of excellent quality to allow evaluation of shoulder integrity. Postsession download and analysis of high-fidelity US images collected onboard demonstrated additional anatomic detail that could be used to exclude subtle injury. Musculoskeletal US can be performed in space by minimally trained operators by using remote guidance. This technique can be used to evaluate shoulder integrity in symptomatic crewmembers after strenuous extravehicular activities or to monitor microgravity-associated changes in musculoskeletal anatomy. Just-in-time training, combined with remote. experienced physician guidance, may provide a useful approach to complex medical tasks performed by nonexperienced personnel in a variety of remote settings, including current and future space programs. C1 Henry Ford Hosp, Dept Surg, Detroit, MI 48202 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Texas Diagnost Imaging, Dallas, TX USA. Henry Ford Hosp, Dept Radiol, Detroit, MI 48202 USA. Wyle Labs, Houston, TX USA. RP Dulchavsky, SA (reprint author), Henry Ford Hosp, Dept Surg, 2799 W Grand Blvd, Detroit, MI 48202 USA. EM sdulcha1@hfhs.org NR 12 TC 47 Z9 49 U1 0 U2 8 PU RADIOLOGICAL SOC NORTH AMERICA PI OAK BROOK PA 820 JORIE BLVD, OAK BROOK, IL 60523 USA SN 0033-8419 J9 RADIOLOGY JI Radiology PD FEB PY 2005 VL 234 IS 2 BP 319 EP 322 DI 10.1148/radiol.2342041680 PG 4 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 890AD UT WOS:000226483200002 PM 15533948 ER PT J AU Lopes, RMC Williams, DA AF Lopes, RMC Williams, DA TI Io after Galileo SO REPORTS ON PROGRESS IN PHYSICS LA English DT Review ID INFRARED MAPPING SPECTROMETER; EXTREME ULTRAVIOLET OBSERVATIONS; JUPITERS SATELLITE IO; G-IMPACT FIREBALL; VOLCANIC ACTIVITY; SULFUR FLOWS; PHOTOPOLARIMETER-RADIOMETER; GLOBAL DISTRIBUTION; HEAT-FLOW; LONGITUDINAL DISTRIBUTION AB lo, the volcanically active innermost large moon of Jupiter, was a target of intense study during the recently completed NASA Galileo mission to Jupiter (1989-2003). Galileo's suite of instruments obtained unprecedented observations of lo, including high spatial resolution imaging in the visible and infrared. This paper reviews the insights gained about lo's surface, atmosphere and space environment during the Galileo mission. lo is thought to have a large Fe-FeS core, whose radius is slightly less than half the radius of lo and whose mass is 20% of the moon.. The lack of an intrinsic magnetic field implies that the core is either completely solid or completely liquid. The mantle of lo appears to undergo a high degree of partial melting (20-50%. molten) that produces ultramafic lavas dominated by Mg-rich orthopyroxene in an apparent 'mushy magma ocean', suggesting an undifferentiated mantle. The crust of lo is thought to be rigid, 20-30 km thick, cold away from volcanic heat sources and composed of mafic to ultrarnafic silicates. Tidal flexing due to lo's orbital resonance produces similar to100m tides at the surface, generating heat that powers Io's volcanism. Silicate volcanism appears to be dominant at most hot spots, although secondary sulfur volcanism may be important in some areas. The key discoveries of the Galileo era at lo were: (1) the detection of high-temperature volcanism (ultramafic, superheated mafic or 'ceramic'); (2) the detection of both S-2 and SO2 gas in Ionian plumes; (3) the distinction between eruption styles, including between Pelean plumes (originating from central vents) and Promethean plumes (originating from silicate lava. flow fronts); (4) the relationship between mountains and paterae, which indicates that many paterae are formed as magma preferentially ascends along tectonics faults associated with mountain building; (5) the lack of detection of an intrinsic magnetic field; (6) a new estimate of global heat flow; and (7) increased understanding of the relationship between lo, its plasma torus and Jupiter's magnetic field. There is an apparent paradox between lo's potentially ultramafic volcanism(suggestive of a primitive, undifferentiated mantle) and the widespread intensity of the volcanism on lo (which should have produced a volume of lava similar to140 times the volume of lo over the last 4.5 Ga, resulting in more silicic materials). The resolution of this paradox requires. either an lo that only recently (geologically) entered its tidal resonance and became volcanically active or a response of lo's lithosphere-mantle to tidal heating that has in some way prevented extreme differentiation. Understanding this problem is one of many important issues about Io that remain unresolved. We conclude this paper with a discussion of the types of future observations, from the ground and from space, that will be needed to address these issues. C1 NASA, Jet Propuls Lab, Pasadena, CA 91109 USA. Arizona State Univ, Dept Geol Sci, Tempe, AZ 85287 USA. RP Lopes, RMC (reprint author), NASA, Jet Propuls Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. RI Lopes, Rosaly/D-1608-2016 OI Lopes, Rosaly/0000-0002-7928-3167 NR 204 TC 18 Z9 18 U1 2 U2 10 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0034-4885 J9 REP PROG PHYS JI Rep. Prog. Phys. PD FEB PY 2005 VL 68 IS 2 BP 303 EP 340 DI 10.1088/0034-4885/68/2/R02 PG 38 WC Physics, Multidisciplinary SC Physics GA 903AZ UT WOS:000227399100002 ER PT J AU Sinha, MP Wadsworth, M AF Sinha, MP Wadsworth, M TI Miniature focal plane mass spectrometer with 1000-pixel modified-CCD detector array for direct ion measurement SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID MICROBORE CAPILLARY COLUMN; FE AB A high performance, focal plane miniature mass spectrometer (MMS) of Mattauch-Herzog geometry with a CCD-based array detector for the direct and simultaneous measurements of different mass ions is described. Miniaturization (10 cmx5 cmx5 cm,395 g) was accomplished by using high-energy-product magnet material (Nd-B-Fe alloy) and a high permeability yoke material (V-Co-Fe Alloy) for the fabrication of the magnetic sector. The electrostatic sector was machined from a single piece of machinable ceramic (MACOR). All the components of the analyzer are mounted on a single plate, which facilitate their alignment and make the instrument rugged. The modified-CCD based ion detector array has 1000 elements (20 mumx2 mm) and was invented in our laboratory. The photosensitive part of the CCD was replaced with a metal-oxide-semiconductor (MOS) capacitor for ion detection. The ion sensing capacitor plates are connected to the CCD gates that are operated in the fill-and spill mode providing a gain in the charge domain for the signal ions and minimizing various noises during measurements. The results reported in this article are the first application of this detector array for direct ion measurement and successfully prove the new technology. The MMS with the array detector can measure masses up to 250 u with a unit mass resolution and expected to possess a sensitivity of detecting similar to5 ions. The above attributes make MMS suitable for space applications for isotopic and chemical analysis and also for field applications on earth. (C) 2005 American Institute of Physics. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Tangent Technol Inc, Monrovia, CA 91016 USA. RP Sinha, MP (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM mahadeva.p.sinha@jpl.nasa.gov NR 34 TC 24 Z9 25 U1 0 U2 7 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 2005 VL 76 IS 2 AR 025103 DI 10.1063/1.1840291 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 893SB UT WOS:000226738400059 ER PT J AU Hill, SM Pizzo, VJ Balch, CC Biesecker, DA Bornmann, P Hildner, E Lewis, LD Grubb, RN Husler, MP Prendergast, K Vickroy, J Greer, S Defoor, T Wilkinson, DC Hooker, R Mulligan, P Chipman, E Bysal, H Douglas, JP Reynolds, R Davis, JM Wallace, KS Russell, K Freestone, K Bagdigian, D Page, T Kerns, S Hoffman, R Cauffman, SA Davis, MA Studer, R Berthiaume, FE Saha, TT Berthiume, GD Farthing, H Zimmermann, F AF Hill, SM Pizzo, VJ Balch, CC Biesecker, DA Bornmann, P Hildner, E Lewis, LD Grubb, RN Husler, MP Prendergast, K Vickroy, J Greer, S Defoor, T Wilkinson, DC Hooker, R Mulligan, P Chipman, E Bysal, H Douglas, JP Reynolds, R Davis, JM Wallace, KS Russell, K Freestone, K Bagdigian, D Page, T Kerns, S Hoffman, R Cauffman, SA Davis, MA Studer, R Berthiaume, FE Saha, TT Berthiume, GD Farthing, H Zimmermann, F TI The NOAA GOES-12 Solar X-ray Imager (SXI) 1. Instrument, operations, and data SO SOLAR PHYSICS LA English DT Article ID TELESCOPE; MISSION AB The Solar X-ray Imager (SXI) was launched 23 July 2001 on NOAAs GOES-12 satellite and completed post-launch testing 20 December 2001. Beginning 22 January 2003 it has provided nearly uninterrupted, full-disk, soft X-ray solar images, with a continuous frame rate significantly exceeding that for previous similar instruments. The SXI provides images with a 1 min cadence and a single-image (adjustable) dynamic range near 100. A set of metallic thin-film filters provides temperature discrimination in the 0.6 - 6.0 nm bandpass. The spatial resolution of approximately 10 arcsec FWHM is sampled with 5 arcsec pixels. Three instrument degradations have occurred since launch, two affecting entrance filters and one affecting the detector high-voltage system. This work presents the SXI instrument, its operations, and its data processing, including the impacts of the instrument degradations. A companion paper (Pizzo et al., this issue) presents SXI performance prior to an instrument degradation that occurred on 5 November 2003 and thus applies to more than 420000 soft X-ray images of the Sun. C1 NOAA, Space Environm Ctr, Boulder, CO 80305 USA. NOAA, Natl Geophys Data Ctr, Boulder, CO 80305 USA. NOAA, NESDIS, Silver Spring, MD 20910 USA. NOAA, NESDIS, SOCC, Suitland, MD 20746 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. MIT, Lincoln Labs, Lexington, MA 02420 USA. Swales Aerosp, Beltsville, MD 20705 USA. Space Syst Loral, Palo Alto, CA 94304 USA. RP Hill, SM (reprint author), NOAA, Space Environm Ctr, 325 Broadway, Boulder, CO 80305 USA. EM steven.hill@noaa.gov NR 28 TC 66 Z9 66 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD FEB PY 2005 VL 226 IS 2 BP 255 EP 281 DI 10.1007/s11207-005-7416-x PG 27 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 927IS UT WOS:000229188200005 ER PT J AU Pizzo, VJ Hill, SM Balch, CC Biesecker, DA Bornmann, P Hildner, E Grubb, RN Chipman, EG Davis, JM Wallace, KS Russell, K Cauffman, SA Saha, TT Berthiume, GD AF Pizzo, VJ Hill, SM Balch, CC Biesecker, DA Bornmann, P Hildner, E Grubb, RN Chipman, EG Davis, JM Wallace, KS Russell, K Cauffman, SA Saha, TT Berthiume, GD TI The NOAA GOES-12 Solar X-ray Imager (SXI) 2. Performance SO SOLAR PHYSICS LA English DT Article AB The Solar X-ray Imager (SXI) was launched on 23 July 2001 on NOAAs GOES-12 satellite and completed post-launch testing on 20 December 2001. It was brought into operations on 21 January 2003. This paper documents SXI performance and calibrations prior to an instrument degradation that occurred on 5 November 2003 and thus covers more than 420000 soft X-ray images of the Sun. This paper details component-level as well as full-system calibrations characterizing the spatial and spectral performance of the instrument, including the grazing-incidence mirror, filters, and the properties of the MCP-intensified CCD detector system. Routine image corrections are also described. These include background (dark current) subtraction, flat-fielding, off-band light-leak correction, and image pointing and timing considerations. In addition, a signal-to-noise analysis is presented. The information contained in this study is intended to enable researchers to conduct quantitative analysis of GOES-12 SXI images. C1 NOAA, Space Environm Ctr, Boulder, CO 80305 USA. NOAA, NESDIS, SOCC, Suitland, MD 20746 USA. NASA, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. MIT, Lincoln Labs, Lexington, MA 02420 USA. RP Pizzo, VJ (reprint author), NOAA, Space Environm Ctr, 325 Broadway, Boulder, CO 80305 USA. EM vic.pizzo@noaa.gov NR 17 TC 35 Z9 35 U1 0 U2 0 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 J9 SOL PHYS JI Sol. Phys. PD FEB PY 2005 VL 226 IS 2 BP 283 EP 315 DI 10.1007/s11207-005-7417-9 PG 33 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 927IS UT WOS:000229188200006 ER PT J AU Cadavid, AC Lawrence, JK McDonald, DP Ruzmaikin, A AF Cadavid, AC Lawrence, JK McDonald, DP Ruzmaikin, A TI Independent global modes of solar magnetic field fluctuations SO SOLAR PHYSICS LA English DT Article ID WAVELET ANALYSIS; COMPONENT ANALYSIS; BLIND SEPARATION; CONVECTION ZONE; CYCLE; WIND; PERIODICITIES; ORIGIN AB Observed solar, interplanetary and geomagnetic time series contain quasi periodicities on scales of 1-2.5 years. The further discovery of 1.3 year fluctuations in helioseismic observations suggests that a variety of signals may be related to the underlying dynamo in the Sun. We use independent component analysis to study the temporal and spatial variations of a few statistically independent global modes of the axisymmetric solar magnetic field over a period of 25 years. Five modes capture the salient properties of the data. Two modes describe the polar and high latitude fields, and present 1-1.5 year quasi periodicities. The other three modes correspond to low and mid-latitude phenomena and show both 1.3 and 1.7-year variations. By comparing the characteristic time scales, dates of occurrence and heliocentric latitudes of these modes, we connect them to their manifestations in heliospheric time series. C1 Calif State Univ Northridge, Dept Phys & Astron, Northridge, CA 91330 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Cadavid, AC (reprint author), Calif State Univ Northridge, Dept Phys & Astron, Northridge, CA 91330 USA. EM ana.cadavid@csun.edu NR 34 TC 23 Z9 23 U1 0 U2 1 PU SPRINGER PI DORDRECHT PA VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS SN 0038-0938 EI 1573-093X J9 SOL PHYS JI Sol. Phys. PD FEB PY 2005 VL 226 IS 2 BP 359 EP 376 DI 10.1007/s11207-005-8187-0 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 927IS UT WOS:000229188200010 ER PT J AU Mendell, W AF Mendell, W TI The vision of human spaceflight SO SPACE POLICY LA English DT Editorial Material AB This viewpoint charts the historical origins of humans' fascination with discovering, and having the possibility of visiting, outer space, arguing that acceptance of change is crucial to realizing such dreams. In the past, change was neither expected nor particularly welcomed but scientific and technological discoveries and advances-often made in the face of 'establishment' (e.g. Church) opposition-have persuaded people of the desirability of progress. Science fiction writers too have played a part in inspiring humans to want to explore the cosmos. Even if the current US Vision for space exploration proves politically unsustainable, today's humans will not abandon their dreams of space travel. Published by Elsevier Ltd. C1 NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. RP Mendell, W (reprint author), NASA, Lyndon B Johnson Space Ctr, 2101 NASA Rd 1, Houston, TX 77058 USA. EM wendell.w.mendell@jsc.nasa.gov NR 5 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0265-9646 J9 SPACE POLICY JI Space Policy PD FEB PY 2005 VL 21 IS 1 BP 7 EP 10 DI 10.1016/j.spacepol.2004.11.009 PG 4 WC International Relations; Social Sciences, Interdisciplinary SC International Relations; Social Sciences - Other Topics GA 904FR UT WOS:000227482000002 ER PT J AU Philip, D Chen, SS Fitzgerald, W Orenstein, J Margolis, L Kleinman, HK AF Philip, D Chen, SS Fitzgerald, W Orenstein, J Margolis, L Kleinman, HK TI Complex extracellular matrices promote tissue-specific stem cell differentiation SO STEM CELLS LA English DT Article DE matrigel; basement membrane; extracellular matrix; gland formation; chondrogenesis ID BASEMENT-MEMBRANE; GROWTH-FACTORS; COMPONENTS; LAMININ; CHONDROCYTES; EXPRESSION; LINE AB Most cells in tissues contact an extracellular matrix on at least one surface. These complex mixtures of interacting proteins provide structural support and biological signals that regulate cell differentiation and may be important for stem cell differentiation. In this study, we have grown a rhesus monkey embryonic stem cell line in the presence of various extracellular matrix components in monolayer, in a NASA-developed rotating wall vessel bioreactor in vitro, and subcutaneously in vivo. We find that individual components of the extracellular matrix, such as laminin-1 or collagen 1, do not influence the growth or morphology of the cells. In contrast, a basement membrane extract, Matrigel, containing multiple extracellular matrix components, induces the cells within 4 days to form immature glandular- and tubular-like structures, many of which contain a lumen with polarized epithelium and microvilli. Such structures were seen in vitro when the cells were grown in the bioreactor and when the cells were injected into mice. These tubular- and glandular-like structures were polarized epithelia based on immunostaining for laminin and cytokeratin. The cell aggregates and tumors also contained additional mixed populations of cells, including mesenchymal cells and neuronal cells, based on immunostaining with vimentin and neuronal markers. An extract of cartilage, containing multiple cartilage matrix components, promoted chondrogenesis in vivo where alcian blue-stained cartilage nodules could be observed. Some of these nodules stained with von Kossa, indicating that they had formed calcified cartilage. We conclude that extracellular matrices can promote the differentiation of embryonic stem cells into differentiated cells and structures that are similar to the tissue from which the matrix is derived. Such preprogramming of cell differentiation with extracellular matrices may be useful in targeting stem cells to repair specific damaged organs. C1 NICHD, NASA, Ctr Dimens Tissue Culture 3, NIH, Bethesda, MD 20892 USA. Natl Inst Dent & Craniofacial Res, Cell Biol Sect, Bethesda, MD USA. George Washington Univ, Med Ctr, Washington, DC 20037 USA. NICHHD, Lab Cellular & Mol Biophys, Bethesda, MD USA. RP Margolis, L (reprint author), NICHD, NASA, Ctr Dimens Tissue Culture 3, NIH, Bldg 10D58, Bethesda, MD 20892 USA. EM margolis@helix.nih.gov NR 21 TC 103 Z9 111 U1 0 U2 6 PU ALPHAMED PRESS PI MIAMISBURG PA ONE PRESTIGE PLACE, STE 290, MIAMISBURG, OH 45342-3758 USA SN 1066-5099 J9 STEM CELLS JI Stem Cells PD FEB PY 2005 VL 23 IS 2 BP 288 EP 296 DI 10.1634/stemcells.2002.0109 PG 9 WC Cell & Tissue Engineering; Biotechnology & Applied Microbiology; Oncology; Cell Biology; Hematology SC Cell Biology; Biotechnology & Applied Microbiology; Oncology; Hematology GA 897FJ UT WOS:000226989100013 PM 15671151 ER PT J AU Bar-Cohen, Y AF Bar-Cohen, Y TI Biologically inspired intelligent robots using artificial muscles SO STRAIN LA English DT Article C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bar-Cohen, Y (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 5 TC 5 Z9 5 U1 1 U2 6 PU BLACKWELL PUBLISHING LTD PI OXFORD PA 9600 GARSINGTON RD, OXFORD OX4 2DG, OXON, ENGLAND SN 0039-2103 J9 STRAIN JI Strain PD FEB PY 2005 VL 41 IS 1 BP 19 EP 24 DI 10.1111/j.1475-1305.2004.00161.x PG 6 WC Materials Science, Characterization & Testing SC Materials Science GA 904WW UT WOS:000227530300004 ER PT J AU Rubinstein, R Choudhari, M AF Rubinstein, R Choudhari, M TI Uncertainty quantification for systems with random initial conditions using Wiener-Hermite expansions SO STUDIES IN APPLIED MATHEMATICS LA English DT Article ID DYNAMICS AB A number of engineering problems, including laminar-turbulent transition in convectively unstable flows, require predicting the evolution of a nonlinear dynamical system under uncertain initial conditions. The method of Wiener-Hermite expansion is an attractive alternative to modeling methods, which solve for the joint probability density function of the stochastic amplitudes. These problems include the "curse of dimensionality" and closure problems. In this paper, we apply truncated Wiener-Hermite expansions with both fixed and time-varying bases to a model stochastic system with three degrees of freedom. The model problem represents the combined effects of quadratic nonlinearity and stochastic initial conditions in a generic setting and occurs in related forms in both classical dynamics, turbulence theory, and the nonlinear theory of hydrodynamic stability. In this problem, the truncated Wiener-Hermite expansions give a good account of short-time behavior, but not of the long-time relaxation characteristic of this system. It is concluded that successful application of truncated Wiener-Hermite expansions may require special adaptations for each physical problem. C1 NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA. RP Rubinstein, R (reprint author), NASA, Langley Res Ctr, Computat Modeling & Simulat Branch, Hampton, VA 23681 USA. EM r.rubinstein@larc.nasa.gov RI Choudhari, Meelan/F-6080-2017 OI Choudhari, Meelan/0000-0001-9120-7362 NR 22 TC 9 Z9 9 U1 0 U2 2 PU BLACKWELL PUBLISHERS PI MALDEN PA 350 MAIN STREET, STE 6, MALDEN, MA 02148 USA SN 0022-2526 J9 STUD APPL MATH JI Stud. Appl. Math. PD FEB PY 2005 VL 114 IS 2 BP 167 EP 188 DI 10.1111/j.0022-2526.2005.01543.x PG 22 WC Mathematics, Applied SC Mathematics GA 889CM UT WOS:000226421100002 ER PT J AU DellaCorte, C AF DellaCorte, C TI Even high fuel prices have an upside! SO TRIBOLOGY & LUBRICATION TECHNOLOGY LA English DT Editorial Material C1 NASA, Glenn Res Ctr, Cleveland, OH USA. RP DellaCorte, C (reprint author), NASA, Glenn Res Ctr, Cleveland, OH USA. EM cdellacorte@stle.org NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 0024-7154 J9 TRIBOL LUBR TECHNOL JI Tribol. Lubr. Technol. PD FEB PY 2005 VL 61 IS 2 BP 6 EP 6 PG 1 WC Engineering, Mechanical SC Engineering GA 895TS UT WOS:000226887100002 ER PT J AU Walker, RJ Brandon, AD Bird, JM Piccoli, PM McDonough, WF Ash, RD AF Walker, RJ Brandon, AD Bird, JM Piccoli, PM McDonough, WF Ash, RD TI Os-187-Os-186 systematics of Os-Ir-Ru alloy grains from southwestern Oregon SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE Os-Ir-Ru alloys; mantle; (OS)-O-186/(OS)-O-188; (OS)-O-187/(OS)-O-188 ID PLATINUM-GROUP MINERALS; HEAZLEWOOD RIVER COMPLEX; RE-OS; UPPER-MANTLE; OS-186-OS-187 SYSTEMATICS; ISOTOPIC SYSTEMATICS; ABYSSAL PERIDOTITES; OSMIUM ISOTOPES; OPHIOLITE; HETEROGENEITY AB More than 100 Os-Ir-Ru alloy grains from southwestern Oregon, presumably originating in the Mesozoic Josephine ophiolite, were examined for major and minor element compositions and Os-187/Os-188 isotopic compositions. Sixteen grains spanning the range of Os-187/Os-188 ratios present in the larger suite were analyzed for high-precision Os-186/Os-188 ratios. The ranges of major and minor element abundances of individual grains were, in general, similar to compositions previously reported for such grains worldwide. Within-suite compositional variations were quite large. Most grains were likely disaggregated from larger intergrown clusters, and were subdivided based on texture into matrix and lamellae. Composition variations within individual matrix grains were limited, whereas variations within individual lamellae grains were considerably larger. The Os-187/Os-188 ratios of individual grains were isotopically homogeneous at the +/-0.1% level of resolution. The Os-187/Os-188 ratios of the entire suite of grains ranged from 0.1173 to 0.1468. The average ratio for all grains combined was 0.?241, similar to the composition of three chromitites sampled from the Josephine Creek, and consistent with formation in the Mesozoic upper mantle. The average Os-186/Os-188 ratio of the subset of 16 grains was 0.119838. All grains but one had isotopic ratios within +/-20 ppm of that ratio. Results indicate that Os-187/Os-188 variations on a scale of mm(3) may be quite large within the upper mantle, mimicking heterogeneities observed in both hand-and outcrop-scale samples of upper mantle materials. Highly depleted compositions relative to ambient upper mantle with chondritic Os-187/Os-188 require that some of the heterogeneities must be >1 Ga. The homogeneity of the Os-186/Os-188 ratios lend no support to the contention that isotopic heterogeneities within the upper mantle may explain coupled Os-186/Os-187 enrichments that have been observed in putative plume derived lavas. (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Maryland, Dept Geol, College Pk, MD 20742 USA. NASA, Lyndon B Johnson Space Ctr, Houston, TX 77058 USA. Cornell Univ, Dept Earth & Atmospher Sci, Ithaca, NY 14853 USA. RP Walker, RJ (reprint author), Univ Maryland, Dept Geol, College Pk, MD 20742 USA. EM rjwalker@geol.umd.edu RI McDonough, William/C-4791-2009; Walker, Richard/K-6869-2016; McDonough, William/I-7720-2012 OI McDonough, William/0000-0001-9154-3673; Walker, Richard/0000-0003-0348-2407; McDonough, William/0000-0001-9154-3673 NR 43 TC 50 Z9 53 U1 0 U2 3 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 JAN 30 PY 2005 VL 230 IS 1-2 BP 211 EP 226 DI 10.1016/j.epsl.2004.11.009 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 895JF UT WOS:000226856400014 ER PT J AU Diner, DJ Martonchik, JV Kahn, RA Pinty, B Gobron, N Nelson, DL Holben, BN AF Diner, DJ Martonchik, JV Kahn, RA Pinty, B Gobron, N Nelson, DL Holben, BN TI Using angular and spectral shape similarity constraints to improve MISR aerosol and surface retrievals over land SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE MISR aerosol and surface retrieval; multi-angle imaging SpectroRaidiometer (MISR) AERONET aerosol sunphotometer data ID OPTICAL DEPTH; INSTRUMENT; AERONET AB The Multi-angle Imaging SpectroRadiorneter (MISR) instrument on the Terra satellite has demonstrated the capability to retrieve aerosol optical depths, surface bidirectional reflectance factors, and hemispherical reflectances over a wide variety of land surface types. In particular. its multiangular imaging design has enabled the application of algorithms that minimize sensitivity of the aerosol retrievals to the brightness of the underlying surface. The novel aerosol algorithm that was developed prior to launch has had notable quantitative success. Over certain scene types, however, the approach contained obvious spatial artifacts, so a postlaunch refinement to the algorithm was implemented. It constrains the retrieved aerosol models and optical depths such that the implied angular shape of the surface hemispherical-directional reflectance factor (HDRF) is similar among all of the MISR wavelengths. This upgrade has resulted in three tangible benefits: (1) the 1 occurrence of outliers has been dramatilcally reduced, (2) correlations with AERosol RObotic NETwork (AERONET) aerosol sunphotometer data are quantitatively improved, and (3) the quality of surface products is markedly enhanced. MISR Level 2 aerosol and surface products are archived at the NASA Langley Atmospheric Sciences Data Center. Those having version numbers v0012 and higher incorporate ibis upgrade in the data processing software. (C) 2004 Elsevier Inc. All rights reserved. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Inst Environm & Sustainabil, Joint Res Ctr, I-21020 Ispra, Italy. UTA TSEP Inc, Pasadena, CA 91101 USA. Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Diner, DJ (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM David.J.Diner@ipl.nasa.gov RI Kahn, Ralph/D-5371-2012 OI Kahn, Ralph/0000-0002-5234-6359 NR 27 TC 91 Z9 99 U1 1 U2 17 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 JAN 30 PY 2005 VL 94 IS 2 BP 155 EP 171 DI 10.1016/j.res.2004.09.009 PG 17 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 886ZC UT WOS:000226270800002 ER PT J AU Foster, JL Sun, CJ Walker, JP Kelly, R Chang, A Dong, JR Powell, H AF Foster, JL Sun, CJ Walker, JP Kelly, R Chang, A Dong, JR Powell, H TI Quantifying the uncertainty in passive microwave snow water equivalent observations SO REMOTE SENSING OF ENVIRONMENT LA English DT Article DE snow cover; snow water equivalent; passive microwave; uncertainty; observation errors; SMMR SSM/I ID COVER; PARAMETERS; REMOTE; ALASKA; WINTER; DEPTH; RADIOMETRY; SIGNATURES; EMISSION; FOREST AB Passive microwave sensors (PM) onboard satellites have the capability to provide global snow observations which are not affected by cloudiness and night condition (except when precipitating events are occurring). Furthermore, they provide information on snow mass. i.e., snow water equivalent (SWE), which is critically important for hydrological modeling and water resource management. However. the errors associated with the passive microwave measurements of SWE are well known but have not been adequately quantified thus far. Understanding these errors is important for correct interpretation of remotely sensed SWE and successful assimilation of such observations into numerical models. This study uses a novel approach to quantify these errors by taking into account various factors, that impact passive microwave responses from snow in various climatic/geographic regions. Among these factors are vegetation cover (particularly forest cover). snow morphology(crystal size), and errors related to brightness temperature calibration. A time-evolving retrieval algorithm that considers the evolution of snow crystals is formulated. An error model is developed based on the standard error estimation theory. This new algorithm and error estimation method is applied to the passive microwave data from Special Sensor Microwave/Imager (SSM/I) during the 1990-1991 snow season to produce annotated error maps for North America. The algorithm has been validated for seven snow seasons (from 1988 to 1995) in taiga, tundra, alpine, prairie, and maritime regions of Canada using in situ SWE data from the Meteorological Service of Canada (MSC) and satellite passive microwave observations. An ongoing study is applying this methodology to passive microwave measurements: from Scanning Multichannel Microwave Radiometer (SMMR); future study will further refine and extend the analysis globally, and produce an improved SWE dataset of more than 25 years in length by combining SSMR and SSM/I measurements. Published by Elsevier Inc. C1 NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Hydrol Sci Branch, Greenbelt, MD 20771 USA. NASA, Goddard Space Flight Ctr, Global Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. Univ Melbourne, Dept Civil & Environm Engn, Parkville, Vic 3010, Australia. Sci Applicat Int Corp, Beltsville, MD 20705 USA. RP Foster, JL (reprint author), NASA, Goddard Space Flight Ctr, Lab Hydrospher Proc, Hydrol Sci Branch, Code 974, Greenbelt, MD 20771 USA. EM James.L.Foster@nasa.gov RI Sun, Chaojiao/A-9569-2011; Walker, Jeffrey/D-2624-2009 OI Sun, Chaojiao/0000-0002-7030-0485; NR 49 TC 144 Z9 160 U1 6 U2 37 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 JAN 30 PY 2005 VL 94 IS 2 BP 187 EP 203 DI 10.1016/j.rse.2004.09.012 PG 17 WC Environmental Sciences; Remote Sensing; Imaging Science & Photographic Technology SC Environmental Sciences & Ecology; Remote Sensing; Imaging Science & Photographic Technology GA 886ZC UT WOS:000226270800004 ER PT J AU Richardson, IG Cane, HV AF Richardson, IG Cane, HV TI The approximate to 150 day quasi-periodicity in interplanetary and solar phenomena during cycle 23 SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID CORONAL MASS EJECTIONS; SUNSPOT AREAS; ACTIVE ZONES; FLARES; SUN; SOLAR-CYCLE-23; FLUXES AB An intermittent quasi-periodicity of similar to 150 days in various solar and interplanetary phenomena has been reported in earlier solar cycles. We suggest that variations in the occurrence of solar energetic particle events, interplanetary coronal mass ejections, and geomagnetic storm sudden commencements during solar cycle 23 show evidence of this quasi-periodicity, which is also present in the sunspot number, in particular in the northern solar hemisphere. It is not, however, prominent in the interplanetary magnetic field strength. C1 NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. Univ Maryland, Dept Astron, College Pk, MD 20742 USA. Univ Tasmania, Sch Math & Phys, Hobart, Tas, Australia. RP Richardson, IG (reprint author), NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Code 661, Greenbelt, MD 20771 USA. EM richardson@lheavx.gsfc.nasa.gov; hilary.cane@utas.edu.au OI Richardson, Ian/0000-0002-3855-3634 NR 23 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 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 29 PY 2005 VL 32 IS 2 AR L02104 DI 10.1029/2004GL021691 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 892XL UT WOS:000226683200007 ER PT J AU Usmanov, AV Goldstein, ML Ogilvie, KW Farrell, WM Lawrence, GR AF Usmanov, AV Goldstein, ML Ogilvie, KW Farrell, WM Lawrence, GR TI Low-density anomalies and sub-Alfvenic solar wind SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID INTERPLANETARY SCINTILLATION OBSERVATIONS; HELIOSPHERIC EQUATORIAL PLANE; FLARE-GENERATED DISTURBANCES; CORONAL MASS EJECTIONS; SPACE WEATHER EVENT; 2-DIMENSIONAL SIMULATION; DISAPPEARANCE EVENT; MAGNETIC-FIELDS; WAVE REFRACTION; MHD MODEL AB [ 1] During 10 - 12 May 1999, the solar wind density dropped to an anomalously low value of similar to0.1 cm(-3). The density depletion occurred in the midst of relatively slow wind flow, in between faster flows, and was apparently associated with neither a coronal mass ejection nor a fast corotating stream. While the magnetic field intensity did not show any notable variation across the density depletion, plasma analyzers on the ACE and Wind spacecraft revealed an abnormally strong nonradial flow component with an azimuthal speed that peaked at similar to100 km s(-1). Usmanov et al. [2000b] suggested that the density anomaly was, in fact, a rarefaction at the trailing edge of relatively fast flow that formed as a result of suppression of coronal outflow from a region that earlier provided fast wind flow. The suppression in turn may have resulted from a rapid restructuring of solar magnetic fields during the polar field reversal. Herewe show results from a two-dimensional time-dependent MHD simulation applied to the helioequatorial plane. The initially longitude-independent Parker solar wind and Archimedean spiral magnetic field are disturbed by a low-velocity/high-density jump on an inner computational boundary at 20 R-.. We follow the development and propagation of the rarefaction to Earth orbit and compare pseudo-time series with near-Earth spacecraft measurements. We show that a strong rarefaction can develop behind the fast flow and that simulation results and spacecraft observations are generally in agreement. The simulated radial magnetic field shows a relatively small variation across the density anomaly compared with that of the density. The stream interaction generates strong azimuthal velocities in the slow flow region, as observed. The simulation shows a sub-Alfvenic flow region embedded within the low-density region that does not extend all the way back to the Sun but which has become disconnected as the depletion propagates to Earth orbit. We discuss also the correlation between low-density and sub-Alfvenic events in the solar wind as inferred from spacecraft observations using the OMNI 2 data set from 1963 to 2003. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Interplanetary Phys Branch, Greenbelt, MD 20771 USA. St Petersburg State Univ, Inst Phys, St Petersburg, Russia. NASA, Goddard Space Flight Ctr, Planetary Magnetospheres Branch, Greenbelt, MD 20771 USA. Observ Royal Belgique, Dept Solar Phys, B-1180 Brussels, Belgium. RP NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Interplanetary Phys Branch, Code 692, Greenbelt, MD 20771 USA. EM usmanov@geo.phys.spbu.ru; melvyn.l.goldstein@nasa.gov; keith.w.ogilvie@nasa.gov; william.m.farrell@nasa.gov; gareth.lawrence@oma.be RI Goldstein, Melvyn/B-1724-2008; Usmanov, Arcadi/A-9860-2013; Farrell, William/I-4865-2013 NR 41 TC 8 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD JAN 28 PY 2005 VL 110 IS A1 AR A01106 DI 10.1029/2004JA010699 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 892YW UT WOS:000226686900004 ER PT J AU Lary, DJ AF Lary, DJ TI Halogens and the chemistry of the free troposphere SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID MARINE BOUNDARY-LAYER; POTENTIAL VORTICITY; RADIATION-FIELD; POLAR VORTEX; OCCULTATION EXPERIMENT; METHANE OXIDATION; DIFFUSE-RADIATION; OZONE; AEROSOL; STRATOSPHERE AB The role of halogens in both the marine boundary layer and the stratosphere has long been recognized, while their role in the free troposphere is often not considered in global chemical models. However, a careful examination of free-tropospheric chemistry constrained by observations using a full chemical data assimilation system shows that halogens do play a significant role in the free troposphere. In particular, the chlorine initiation of methane oxidation in the free troposphere can contribute more than 10%, and in some regions up to 50%, of the total rate of initiation. The initiation of methane oxidation by chlorine is particularly important below the polar vortex and in northern mid-latitudes. Likewise, the hydrolysis of BrONO2 alone can contribute more than 35% of the HNO3 production rate in the free-troposphere. C1 NASA, Global Modelling & Assimilat Off, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, GEST, Baltimore, MD 21228 USA. RP Lary, DJ (reprint author), NASA, Global Modelling & Assimilat Off, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM David.Lary@umbc.edu RI Lary, David/A-6163-2010 NR 68 TC 17 Z9 18 U1 1 U2 4 PU EUROPEAN GEOSCIENCES UNION PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD JAN 27 PY 2005 VL 5 BP 227 EP 237 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 891NC UT WOS:000226586800002 ER PT J AU Wong, EW Bronikowski, MJ Hoenk, ME Kowalczyk, RS Hunt, BD AF Wong, EW Bronikowski, MJ Hoenk, ME Kowalczyk, RS Hunt, BD TI Submicron patterning of iron nanoparticle monolayers for carbon nanotube growth SO CHEMISTRY OF MATERIALS LA English DT Article ID CATALYTIC PRODUCTION; CVD SYNTHESIS; DEPOSITION; WAFERS; MO AB We describe a method to reliably pattern monolayers of iron nanoparticle (FeNP) colloids into submicron features for growth of single-walled carbon nanotubes (SWNTs) by chemical vapor deposition. Our process results in very clean patterns that are readily imaged by atomic force microscopy, which has allowed the observation of nanoparticle size evolution before and after high-temperature nanotube growth. For our growth conditions, SWNTs grew only from nanoparticles smaller than similar to5 nm high. At the high growth temperature of 850 degreesC, nanoparticle sintering was clearly evident and had important effects on nanotube yield from the FeNP catalyst. The nanoparticle sintering and growth are drastically accelerated by brief reduction in H-2, resulting in nanoparticles that were too large to catalyze SWNT growth. The results suggest that if ultimate control over SWNT diameters is to be achieved from patterned nanoparticle catalysts, it will be critical to control nanoparticle aggregation and sintering during SNWT growth. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Wong, EW (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Eric.W.Wong@jpl.nasa.aov NR 24 TC 32 Z9 32 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD JAN 25 PY 2005 VL 17 IS 2 BP 237 EP 241 DI 10.1021/cm048795m PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 889ZC UT WOS:000226480400007 ER PT J AU Giampieri, G Dougherty, MK Russell, CT Smith, EJ AF Giampieri, G Dougherty, MK Russell, CT Smith, EJ TI Reply to comment by M. L. Kaiser et al. on "Rotation rate of Saturn's interior from magnetic field observations'' SO GEOPHYSICAL RESEARCH LETTERS LA English DT Editorial Material ID PERIOD; MODEL C1 Univ London Imperial Coll Sci Technol & Med, Dept Math, London SW7 2AZ, England. Univ London Imperial Coll Sci Technol & Med, London SW7 2BW, England. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90024 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Giampieri, G (reprint author), Univ London Imperial Coll Sci Technol & Med, Dept Math, Huxley Bldg, London SW7 2AZ, England. EM g.giampieri@imperial.ac.uk NR 8 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 JAN 25 PY 2005 VL 32 IS 2 AR L02202 DI 10.1029/2004GL021684 PG 2 WC Geosciences, Multidisciplinary SC Geology GA 892XD UT WOS:000226682400003 ER PT J AU Jo, YH Yan, XH Dzwonkowski, B Liu, WT AF Jo, YH Yan, XH Dzwonkowski, B Liu, WT TI A study of the freshwater discharge from the Amazon River into the tropical Atlantic using multi-sensor data SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID OCEAN HEAT-STORAGE; TOPEX AB We study freshwater discharge from the Amazon River into the tropical Atlantic using monthly mean multi-sensor data from September 1997 to July 2003. In order to demonstrate freshwater discharge, we used chlorophyll concentration (Chl_ a) and diffuse attenuation coefficient (DAC) measured by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS), and salt steric height anomaly ( Deltaeta'(s)) derived from Integrated Multi-Sensor Data Analysis (IMSDA). IMSDA was obtained from estimating the long term-time series of Deltaeta'(s) by removing the thermal steric height anomaly (eta'(T)) from altimetry data. Comparisons of long-term time series of Deltaeta'(s), Chl_ a, and DAC were made with mooring data at 8degreesN, 38degreesW, which were highly correlated. There are three- to five-month lags between the Amazon River discharge and 4 degreesN latitude estimated from latitude-time diagram derived from SeaWiFS measurements. C1 Univ Delaware, Grad Coll Marine Studies, Ctr Remote Sensing, Newark, DE 19716 USA. Ocean Univ China, Ocean Remote Sensing Inst, Qingdao, Peoples R China. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Jo, YH (reprint author), Univ Delaware, Grad Coll Marine Studies, Ctr Remote Sensing, Newark, DE 19716 USA. EM xiaohai@udel.edu OI Dzwonkowski, Brian/0000-0002-2333-2185 NR 13 TC 5 Z9 5 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 25 PY 2005 VL 32 IS 2 AR L02605 DI 10.1029/2004GL021840 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 892XD UT WOS:000226682400004 ER PT J AU Kaiser, ML Desch, MD Acuna, MH Ness, NF Connerney, JEP AF Kaiser, ML Desch, MD Acuna, MH Ness, NF Connerney, JEP TI Comment on "Rotation rate of Saturn's interior from magnetic field observations'' by Giacomo Giampieri and Michele K. Dougherty SO GEOPHYSICAL RESEARCH LETTERS LA English DT Editorial Material ID MAGNETOSPHERE; VOYAGER-1; PERIOD; MODEL C1 NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Delaware, Bartol Res Inst, Newark, DE 19716 USA. RP Kaiser, ML (reprint author), NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. EM michael.l.kaiser@nasa.gov RI connerney, john/I-5127-2013 NR 12 TC 1 Z9 1 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 JAN 25 PY 2005 VL 32 IS 2 AR L02201 DI 10.1029/2004GL021398 PG 2 WC Geosciences, Multidisciplinary SC Geology GA 892XD UT WOS:000226682400002 ER PT J AU Behrenfeld, MJ Boss, E Siegel, DA Shea, DM AF Behrenfeld, MJ Boss, E Siegel, DA Shea, DM TI Carbon-based ocean productivity and phytoplankton physiology from space SO GLOBAL BIOGEOCHEMICAL CYCLES LA English DT Article ID SUB-ARCTIC PACIFIC; IRON ENRICHMENT EXPERIMENTS; PARTICULATE ORGANIC-CARBON; ATLANTIC TIME-SERIES; EQUATORIAL PACIFIC; LIGHT-SCATTERING; SARGASSO SEA; CHLOROPHYLL CONCENTRATION; SEASONAL VARIABILITY; SUBTROPICAL GYRE AB Ocean biogeochemical and ecosystem processes are linked by net primary production (NPP) in the ocean's surface layer, where inorganic carbon is fixed by photosynthetic processes. Determinations of NPP are necessarily a function of phytoplankton biomass and its physiological status, but the estimation of these two terms from space has remained an elusive target. Here we present new satellite ocean color observations of phytoplankton carbon (C) and chlorophyll (Chl) biomass and show that derived Chl:C ratios closely follow anticipated physiological dependencies on light, nutrients, and temperature. With this new information, global estimates of phytoplankton growth rates (mu) and carbon-based NPP are made for the first time. Compared to an earlier chlorophyll-based approach, our carbon-based values are considerably higher in tropical oceans, show greater seasonality at middle and high latitudes, and illustrate important differences in the formation and demise of regional algal blooms. This fusion of emerging concepts from the phycological and remote sensing disciplines has the potential to fundamentally change how we model and observe carbon cycling in the global oceans. C1 NASA, Sci Applicat Int Corp, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Univ Maine, Sch Marine Sci, Orono, ME 04469 USA. Univ Calif Santa Barbara, Inst Computat Earth Syst Sci, Santa Barbara, CA 93106 USA. RP Behrenfeld, MJ (reprint author), Oregon State Univ, Dept Bot & Plant Pathol, Cordley Hall,2082, Corvallis, OR 97331 USA. EM behrenfm@science.oregonstate.edu; emmanuel.boss@maine.edu; davey@icess.ucsb.edu; don.shea@gsfc.nasa.gov RI Boss, Emmanuel/C-5765-2009; Siegel, David/C-5587-2008 OI Boss, Emmanuel/0000-0002-8334-9595; NR 60 TC 320 Z9 325 U1 4 U2 88 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0886-6236 J9 GLOBAL BIOGEOCHEM CY JI Glob. Biogeochem. Cycle PD JAN 25 PY 2005 VL 19 IS 1 AR GB1006 DI 10.1029/2004GB002299 PG 14 WC Environmental Sciences; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Geology; Meteorology & Atmospheric Sciences GA 892XN UT WOS:000226683400001 ER PT J AU Yang, JH Dass, A Sotiriou-Leventis, C Tyson, DS Leventis, N AF Yang, JH Dass, A Sotiriou-Leventis, C Tyson, DS Leventis, N TI Synthesis and near IR photoluminescence of Os(II) bis(2,2 '-bipyridine) (3,8-diarylethynyl-1,10-phenanthroline) complexes: anomalous behavior in the 3,8-dinitrophenylethynyl-substituted homologue SO INORGANICA CHIMICA ACTA LA English DT Article DE emission; near ir; osmium; complex ID FREE-ENERGY RELATIONSHIPS; INFRARED ABSORBING DYES; ELECTROCHEMICAL-BEHAVIOR; COORDINATION-COMPOUNDS; POLYPYRIDYL COMPLEXES; ABSORPTION-SPECTRA; BUILDING-BLOCKS; EXCITED-STATES; STEP SYNTHESIS; SUBSTITUTION AB A large bathochromic shift (greater than or equal to50 nm) and emission in the near infrared is observed by attaching arylethynyl groups at the 3,8-positions of the 1,10-phenanthroline ligand (phen) of [Os(bipy)(2)(phen)](2+) (where bipy = 2,2'-bipyridine). Thus [Os(bipy)(2)(3,8-di-4-methoxyphenylethynyl-1,10-phenathroline)](2+) emits at 795 nm, while [Os(bipy)(2)(3,8-diphenylethynyl-1,10-phenanthroline)](2+) emits at 815 nm. According to this trend it would have been expected that [Os(bipy)2(3,8-di-4-nitrophenylethynyl-1,10-phenathroline)](2+) emits farther in the near infrared. Nevertheless, this complex is not photoluminescent because of intramolecular electron transfer quenching of the MLCT excited state by the nitroaromatic group. These results set structural and redox potential standards in the design of near infrared emitters based on [Os(bipy)(2)(phen)](2+) type complexes. Published by Elsevier B.V. C1 Univ Missouri, Dept Chem, Rolla, MO 65409 USA. NASA, Glenn Res Ctr, Div Mat, Cleveland, OH 44135 USA. RP Sotiriou-Leventis, C (reprint author), Univ Missouri, Dept Chem, Rolla, MO 65409 USA. EM cslevent@umr.edu; nicholas.leventis@nasa.gov RI Dass, Amal/A-2520-2011; Dass, Amala/H-4729-2012 OI Dass, Amala/0000-0001-6942-5451 NR 29 TC 7 Z9 7 U1 0 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD JAN 25 PY 2005 VL 358 IS 2 BP 389 EP 395 DI 10.1016/j.ica.2004.08.012 PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 886LP UT WOS:000226229100018 ER PT J AU Leboissetier, A Okong'o, N Bellan, J AF Leboissetier, A Okong'o, N Bellan, J TI Consistent large-eddy simulation of a temporal mixing layer laden with evaporating drops. Part 2. A posteriori modelling SO JOURNAL OF FLUID MECHANICS LA English DT Article ID DIRECT NUMERICAL-SIMULATION; MACH-NUMBER TURBULENCE; SUBGRID-SCALE MODELS; FLOWS; COMBUSTION; DISPERSION; CHANNEL AB Large-eddy simulation (LES) is conducted of a three-dimensional temporal mixing layer whose lower stream is initially laden with liquid drops which may evaporate during the simulation. The gas-phase equations are written in an Eulerian frame for two perfect gas species (carrier gas and vapour emanating from the drops), while the liquid-phase equations are written in a Lagrangian frame. The effect of drop evaporation on the gas phase is considered through mass, species, momentum and energy source terms. The drop evolution is modelled using physical drops, or using computational drops to represent the physical drops. Simulations are performed using various LES models previously assessed on a database obtained from direct numerical simulations (DNS). These LES models are for: (i) the subgrid-scale (SGS) fluxes and (ii) the filtered source terms (FSTs) based on computational drops. The LES, which are compared to filtered-and-coarsened (FC) DNS results at the coarser LES grid, are conducted with 64 times fewer grid points than the DNS, and up to 64 times fewer computational than physical drops. It is found that both constant-coefficient and dynamic Smagorinsky SGS-flux models, though numerically stable, are overly dissipative and damp generated small-resolved-scale (SRS) turbulent structures. Although the global growth and mixing predictions of LES using Smagorinsky models are in good agreement with the FC-DNS, the spatial distributions of the drops differ significantly. In contrast, the constant-coefficient scale-similarity model and the dynamic gradient model perform well in predicting most flow features, with the latter model having the advantage of not requiring a priori calibration of the model coefficient. The ability of the dynamic models to determine the model coefficient during LES is found to be essential since the constant-coefficient gradient model, although more accurate than the Smagorinsky model, is not consistently numerically stable despite using DNS-calibrated coefficients. With accurate SGS-flux models, namely scale-similarity and dynamic gradient, the FST model allows up to a 32-fold reduction in computational drops compared to the number of physical drops, without degradation of accuracy; a 64-fold reduction leads to a slight decrease in accuracy. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Bellan, J (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. EM Josette.Bellan@jpl.nasa.gov NR 34 TC 27 Z9 27 U1 0 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4211 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD JAN 25 PY 2005 VL 523 BP 37 EP 78 DI 10.1017/S0022112004002101 PG 42 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 898KI UT WOS:000227075300002 ER PT J AU Skelley, AM Scherer, JR Aubrey, AD Grover, WH Ivester, RHC Ehrenfreund, P Grunthaner, FJ Bada, JL Mathies, RA AF Skelley, AM Scherer, JR Aubrey, AD Grover, WH Ivester, RHC Ehrenfreund, P Grunthaner, FJ Bada, JL Mathies, RA TI Development and evaluation of a microdevice for amino acid biomarker detection and analysis on Mars SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE amino acid analysis; astrobiology; capillary electrophoresis; microfabrication ID MARTIAN METEORITE ALH84001; EXTRATERRESTRIAL EXPLORATION; ATACAMA DESERT; LIFE; SEARCH; ENANTIOMERS; BACTERIA; DEVICES; SAMPLES; SOILS AB The Mars Organic Analyzer (MOA), a microfabricated capillary electrophoresis (CE) instrument for sensitive amino acid biomarker analysis, has been developed and evaluated. The microdevice consists of a four-wafer sandwich combining glass CE separation channels, microfabricated pneumatic membrane valves and pumps, and a nanoliter fluidic network. The portable MOA instrument integrates high voltage CE power supplies, pneumatic controls, and fluorescence detection optics necessary for field operation. The amino acid concentration sensitivities range from micromolar to 0.1 nM, corresponding to part-per-trillion sensitivity. The MOA was first used in the lab to analyze soil extracts from the Atacama Desert, Chile, detecting amino acids ranging from 10-600 parts per billion. Field tests of the MOA in the Panoche Valley, CA, successfully detected amino acids at 70 parts per trillion to 100 parts per billion in jarosite, a sulfate-rich mineral associated with liquid water that was recently detected on Mars. These results demonstrate the feasibility of using the MOA to perform sensitive in situ amino acid biomarker analysis on soil samples representative of a Mars-like environment. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif San Diego, Scripps Inst Oceanog, La Jolla, CA 92093 USA. Leiden Univ, Astrobiol Lab, NL-2300 RA Leiden, Netherlands. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Mathies, RA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM rich@zinc.cchem.berkeley.edu RI Grover, William/E-6995-2011; OI Grover, William/0000-0001-6854-8951 NR 29 TC 169 Z9 171 U1 6 U2 46 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JAN 25 PY 2005 VL 102 IS 4 BP 1041 EP 1046 DI 10.1073/pnas.0406798102 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 891YW UT WOS:000226617900017 PM 15657130 ER PT J AU Shukla, S Ludwig, L Parrish, C Seal, S AF Shukla, S Ludwig, L Parrish, C Seal, S TI Inverse-catalyst-effect observed for nanocrystalline-doped tin oxide sensor at lower operating temperatures SO SENSORS AND ACTUATORS B-CHEMICAL LA English DT Article DE hydrogen; indium oxide; inverse-catalyst-effect; lower operating temperatures; sensor; sol-gel; thin films; tin oxide ID GAS SENSOR; THIN-FILMS; PERFORMANCES; THICKNESS; H-2; CO AB Nanocrystalline In2O3-doped SnO2 thin film sensor is synthesized via sol-gel dip-coating technique. This nanocrystalline thin film is successfully utilized to sense hydrogen (H-2) gas with the concentration as low as 50 ppm at lower operating temperatures (25-100 degreesC). For short test-duration (30 min), the H-2 sensitivity of the Pt-sputtered sensor is observed to be higher than that of the non-Pt-sputtered film. An "inverse-catalyst-effect" on the H-2) gas sensitivity is, however, newly observed when the test-duration is increased to 24 h. The presence of H2O molecules, which remain adsorbed and get accumulated on the sensor surface, during the long test-duration, are primarily attributed to the reduced H-2 gas sensitivity of the Pt-sputtered sensors, relative to that of non-Pt- sputtered sensors, at lower operating temperatures (25-100 degreesC). (C) 2004 Elsevier B.V. All rights reserved. C1 Univ Cent Florida, Surface Engn & Nanotechnol Facil, MMAE Dept, Orlando, FL 32826 USA. Univ Cent Florida, Adv Mat Proc & Anal Ctr, Orlando, FL 32826 USA. NASA, Kennedy Space Ctr, Orlando, FL 32899 USA. RP Seal, S (reprint author), Univ Cent Florida, Surface Engn & Nanotechnol Facil, MMAE Dept, 381,4000 Cent Florida Blvd, Orlando, FL 32826 USA. EM sshukla@pegasus.cc.ucf.edu OI Shukla, Satyajit/0000-0002-7947-8095 NR 13 TC 27 Z9 27 U1 0 U2 10 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-4005 J9 SENSOR ACTUAT B-CHEM JI Sens. Actuator B-Chem. PD JAN 24 PY 2005 VL 104 IS 2 BP 223 EP 231 DI 10.1016/j.snb.2004.05.008 PG 9 WC Chemistry, Analytical; Electrochemistry; Instruments & Instrumentation SC Chemistry; Electrochemistry; Instruments & Instrumentation GA 874XP UT WOS:000225384200008 ER PT J AU Reichle, RH Koster, RD AF Reichle, RH Koster, RD TI Global assimilation of satellite surface soil moisture retrievals into the NASA Catchment land surface model SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BRIGHTNESS TEMPERATURE; SIMULATIONS; METHODOLOGY; PARAMETERS; IMPACT AB Global retrievals of surface soil moisture from the Scanning Multichannel Microwave Radiometer for the period 1979 - 87 are assimilated into the NASA Catchment land surface model as it is driven with surface meteorological data derived from observations. Validation against ground-based measurements in Eurasia and North America from the Global Soil Moisture Data Bank demonstrates a long assumed ( but rarely proven) property of soil moisture fields derived from data assimilation - that the assimilation product is superior to either satellite data or model data alone. An analysis of the innovations reveals that the filter is only partially operating within its underlying assumptions and offers clues how spatially distributed model error parameters could further enhance filter performance. C1 NASA, Goddard Space Flight Ctr, Globel Modeling & Assimilat Off, Greenbelt, MD 20771 USA. Univ Maryland Baltimore Cty, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. RP Reichle, RH (reprint author), NASA, Goddard Space Flight Ctr, Globel Modeling & Assimilat Off, Code 900-3,Greenbelt Rd, Greenbelt, MD 20771 USA. EM reichle@gmao.gsfc.nasa.gov RI Reichle, Rolf/E-1419-2012; Koster, Randal/F-5881-2012 OI Koster, Randal/0000-0001-6418-6383 NR 18 TC 95 Z9 97 U1 4 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JAN 22 PY 2005 VL 32 IS 2 AR L02404 DI 10.1029/2004GL021700 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 891JY UT WOS:000226578400002 ER PT J AU Feng, W Chipperfield, MP Davies, S Sen, B Toon, G Blavier, JF Webster, CR Volk, CM Ulanovsky, A Ravegnani, F von der Gathen, P Jost, H Richard, EC Claude, H AF Feng, W Chipperfield, MP Davies, S Sen, B Toon, G Blavier, JF Webster, CR Volk, CM Ulanovsky, A Ravegnani, F von der Gathen, P Jost, H Richard, EC Claude, H TI Three-dimensional model study of the Arctic ozone loss in 2002/2003 and comparison with 1999/2000 and 2003/2004 SO ATMOSPHERIC CHEMISTRY AND PHYSICS LA English DT Article ID DELTA-EDDINGTON APPROXIMATION; CHEMICAL-TRANSPORT MODEL; LOWER STRATOSPHERE; POLAR VORTEX; WINTER; DEPLETION; TROPOSPHERE; CHEMISTRY AB We have used the SLIMCAT 3-D off-line chemical transport model (CTM) to quantify the Arctic chemical ozone loss in the year 2002/2003 and compare it with similar calculations for the winters 1999/2000 and 2003/2004. Recent changes to the CTM have improved the model's ability to reproduce polar chemical and dynamical processes. The updated CTM uses sigma-theta as a vertical coordinate which allows it to extend down to the surface. The CTM has a detailed stratospheric chemistry scheme and now includes a simple NAT-based denitrification scheme in the stratosphere. In the model runs presented here the model was forced by ECMWF ERA40 and operational analyses. The model used 24 levels extending from the surface to similar to55 km and a horizontal resolution of either 7.5degrees x 7.5degrees or 2.8degrees x 2.8degrees. Two different radiation schemes, MIDRAD and the CCM scheme, were used to diagnose the vertical motion in the stratosphere. Based on tracer observations from balloons and aircraft, the more sophisticated CCM scheme gives a better representation of the vertical transport in this model which includes the troposphere. The higher resolution model generally produces larger chemical O-3 depletion, which agrees better with observations. The CTM results show that very early chemical ozone loss occurred in December 2002 due to extremely low temperatures and early chlorine activation in the lower stratosphere. Thus, chemical loss in this winter started earlier than in the other two winters studied here. In 2002/2003 the local polar ozone loss in the lower stratosphere was similar to40% before the stratospheric final warming. Larger ozone loss occurred in the cold year 1999/2000 which had a persistently cold and stable vortex during most of the winter. For this winter the current model, at a resolution of 2.8degrees x 2.8degrees, can reproduce the observed loss of over 70% locally. In the warm and more disturbed winter 2003/2004 the chemical O3 loss was generally much smaller, except above 620 K where large losses occurred due to a period of very low minimum temperatures at these altitudes. C1 Univ Leeds, Sch Earth & Environm, Inst Atmospher Sci, Leeds, W Yorkshire, England. NASA, Jet Prop Lab, Pasadena, CA USA. Univ Frankfurt, D-6000 Frankfurt, Germany. CAO, Moscow, Russia. Italian Natl Res Council, ISAC, Bologna, Italy. Alfred Wegener Inst Polar & Marine Res, Potsdam, Germany. NASA, Ames Res Ctr, Moffett Field, CA 94035 USA. NOAA, Aeron Lab, Boulder, CO 80303 USA. Deutsch Wetterdienst, Offenbach, Germany. RP Feng, W (reprint author), Univ Leeds, Sch Earth & Environm, Inst Atmospher Sci, Leeds, W Yorkshire, England. EM fengwh@env.leeds.ac.uk; martyn@env.leeds.ac.uk RI FENG, WUHU/B-8327-2008; von der Gathen, Peter/B-8515-2009; Chipperfield, Martyn/H-6359-2013; Ravegnani, Fabrizio/A-7800-2009 OI FENG, WUHU/0000-0002-9907-9120; von der Gathen, Peter/0000-0001-7409-1556; Chipperfield, Martyn/0000-0002-6803-4149; Ravegnani, Fabrizio/0000-0003-0735-9297 NR 30 TC 47 Z9 47 U1 1 U2 5 PU EUROPEAN GEOSCIENCES UNION PI KATLENBURG-LINDAU PA MAX-PLANCK-STR 13, 37191 KATLENBURG-LINDAU, GERMANY SN 1680-7324 J9 ATMOS CHEM PHYS JI Atmos. Chem. Phys. PD JAN 21 PY 2005 VL 5 BP 139 EP 152 PG 14 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 889NK UT WOS:000226449500004 ER PT J AU Yurtsever, U Hockney, G AF Yurtsever, U Hockney, G TI Signalling, entanglement and quantum evolution beyond Cauchy horizons SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article ID NONLINEAR SCHRODINGER-EQUATIONS; INDUCED COHERENCE; MECHANICS AB Consider a bipartite entangled system, half of which falls through the event horizon of an evaporating black hole, while the other half remains coherently accessible to experiments in the exterior region. Beyond complete evaporation, the evolution of the quantum state past the Cauchy horizon cannot remain unitary, raising the questions: how can this evolution be described as a quantum map, and how is causality preserved? What are the possible effects of such non-standard quantum evolution maps on the behaviour of the entangled laboratory partner? More generally, the laws of quantum evolution under extreme conditions in remote regions (not just in evaporating black-hole interiors, but possibly near other naked singularities and regions of extreme spacetime structure) remain untested by observation, and might conceivably be non-unitary or even nonlinear, raising the same questions about the evolution of entangled states. The answers to these questions are subtle, and are linked in unexpected ways to the fundamental laws of quantum mechanics. We show that terrestrial experiments can be designed to probe and constrain exactly how the laws of quantum evolution might be altered, either by black-hole evaporation, or by other extreme processes in remote regions possibly governed by unknown physics. C1 CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, Pasadena, CA 91109 USA. RP Yurtsever, U (reprint author), CALTECH, Jet Prop Lab, Quantum Comp Technol Grp, 4800 Oak Grove Dr,Mail Stop 126-347, Pasadena, CA 91109 USA. EM Ulvi.Yurisever@jpl.nasa.gov; George.Hockney@jpl.nasa.gov NR 30 TC 11 Z9 11 U1 1 U2 3 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 JAN 21 PY 2005 VL 22 IS 2 BP 295 EP 312 DI 10.1088/0264-9381/22/2/004 PG 18 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 917NT UT WOS:000228470100004 ER PT J AU Joughin, I MacAyeal, DR AF Joughin, I MacAyeal, DR TI Calving of large tabular icebergs from ice shelf rift systems SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID ANTARCTICA AB We used Interferometric Synthetic Aperture Radar to study the detachment process that allowed two large icebergs to calve from the Ross Ice Shelf, Antarctica. Time series of rift geometries indicate that rift widths increased steadily, whereas rift lengths increased episodically through several discrete rift-tip propagation events. We also conducted modeling experiments constrained by the observed rift geometry. Both the observations and model suggest that rift opening, and, thus, tabular-iceberg calving, are largely driven by "glaciological" stresses - stress introduced by the effect of gravity on the ice shelf - rather than by stress introduced by the ocean and atmosphere, e. g., tides and storms. This style of rift propagation is expected to determine the steady, background calving rate of ice shelves and, thus, differs significantly from styles that led to the recent disintegration of ice shelves in response to climate warming, e.g., the Larsen B Ice Shelf on the Antarctic Peninsula. C1 CALTECH, Jet Prop Lab, Pasadena, CA USA. Univ Chicago, Dept Geophys Sci, Chicago, IL 60637 USA. RP Joughin, I (reprint author), Univ Washington, Appl Phys Lab, Polar Sci Ctr, 1013 NE 40th St, Seattle, WA 98105 USA. EM ian@apl.washington.edu; drm7@midway.uchicago.edu RI Joughin, Ian/A-2998-2008 OI Joughin, Ian/0000-0001-6229-679X NR 13 TC 32 Z9 32 U1 0 U2 7 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 JAN 21 PY 2005 VL 32 IS 2 AR L02501 DI 10.1029/2004GL020978 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 891JX UT WOS:000226578300001 ER PT J AU Khavaran, A Bridges, J AF Khavaran, A Bridges, J TI Modelling of fine-scale turbulence mixing noise SO JOURNAL OF SOUND AND VIBRATION LA English DT Article ID JET; PREDICTION; ANALOGY AB The present paper is a study of aerodynamic noise spectra from model functions that describe the source. The study is motivated by the need to improve the spectral shape of the MGBK jet noise prediction methodology at high frequency. The predicted spectral shape usually appears less broadband than measurements and faster decaying at high frequency. Theoretical representation of the source is based on Lilley's equation. Numerical simulations of high-speed subsonic jets as well as some recent turbulence measurements reveal a number of interesting statistical properties of turbulence correlation functions that may have a bearing on radiated noise. These studies indicate that an exponential spatial function may be a more appropriate representation of a two-point correlation compared to its Gaussian counterpart. The effect of source non-compactness on spectral shape is discussed. It is shown that source non-compactness could well be the differentiating factor between the Gaussian and exponential model functions. In particular, the fall-off of the noise spectra at high frequency is studied and it is shown that a noncompact source with an exponential model function results in a broader spectrum and better agreement with data. A recent source model proposed by Tam and Auriault that represents the source as a covariance of the convective derivative of fine-scale turbulence kinetic energy is also examined. (C) 2004 Elsevier Ltd. All rights reserved. C1 NASA, Glenn Res Ctr, QSS Grp Inc, Cleveland, OH 44135 USA. NASA, Glenn Res Ctr, Acoust Branch, Cleveland, OH 44135 USA. RP Khavaran, A (reprint author), NASA, Glenn Res Ctr, QSS Grp Inc, Cleveland, OH 44135 USA. EM khavaran@grc.nasa.gov NR 22 TC 12 Z9 13 U1 0 U2 7 PU ACADEMIC PRESS LTD ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD JAN 21 PY 2005 VL 279 IS 3-5 BP 1131 EP 1154 DI 10.1016/j.jsv.2003.11.054 PG 24 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA 881TH UT WOS:000225891800028 ER PT J AU Hakala, P Ramsay, G Muhli, P Charles, P Hannikainen, D Mukai, K Vilhu, O AF Hakala, P Ramsay, G Muhli, P Charles, P Hannikainen, D Mukai, K Vilhu, O TI XMM-Newton observations of UWCrB: detection of X-ray bursts and evidence for accretion disc evolution SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; binaries : close; stars : individual : UWCrB; X-rays : binaries; X-rays : bursts ID UW CORONAE BOREALIS; MS 1603.6+2600; BINARY; LIGHT AB UW CrB (MS 1603 + 2600) is a peculiar short-period X-ray binary that exhibits extraordinary optical behaviour. The shape of the optical light curve of the system changes drastically from night to night, without any changes in overall brightness. Here we report X-ray observations of UWCrB obtained with XMM-Newton. We find evidence for several X-ray bursts, confirming a neutron star primary. This considerably strengthens the case that UW CrB is an accretion disc corona system located at a distance of at least 5-7 kpc (3- 5 kpc above the Galactic plane). The X-ray and Optical Monitor (ultraviolet-optical) light curves show remarkable shape variation from one observing run to another, which we suggest are due to large-scale variations in the accretion disc shape resulting from a warp that periodically obscures the optical and soft X-ray emission. This is also supported by the changes in phase-resolved X-ray spectra. C1 Univ Helsinki, Observatory, FIN-00014 Helsinki, Finland. UCL, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England. Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Hakala, P (reprint author), Univ Helsinki, Observatory, POB 14, FIN-00014 Helsinki, Finland. EM pahakala@astro.helsinki.fi NR 19 TC 9 Z9 9 U1 0 U2 0 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD JAN 21 PY 2005 VL 356 IS 3 BP 1133 EP 1138 DI 10.1111/j.1365-2966.2004.08543.x PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 889DE UT WOS:000226422900036 ER PT J AU Stern, D Yost, SA Eckart, ME Harrison, FA Helfand, DJ Djorgovski, SG Malhotra, S Rhoads, JE AF Stern, D Yost, SA Eckart, ME Harrison, FA Helfand, DJ Djorgovski, SG Malhotra, S Rhoads, JE TI A galaxy at z=6.545 and constraints on the epoch of reionization SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; early universe; galaxies : formation; galaxies : high-redshift ID LY-ALPHA EMITTERS; GUNN-PETERSON TROUGH; PROBE WMAP OBSERVATIONS; COSMOLOGICAL REIONIZATION; HIGH-REDSHIFT; SPECTROSCOPIC CONFIRMATION; INTERGALACTIC MEDIUM; NEUTRAL HYDROGEN; EMISSION-LINES; BAND DROPOUT AB We report the discovery of a Lyalpha-emitting galaxy at redshift z = 6.545 serendipitously identified in the course of spectroscopic follow-up of hard X-ray sources on behalf of the Serendipitous Extragalactic X-Ray Source Identification (SEXSI) survey. The line flux of the galaxy, 2.1 x 10(-17) ergs cm(-2) s(-1), is similar to line fluxes probed by narrowband imaging surveys; the 5.2 arcmin(2) surveyed implies a surface density of z approximate to 6: 5 Lyalpha emitters somewhat higher than that inferred from narrowband surveys. This source marks the sixth Lyalpha-emitting galaxy identified at z approximate to 6.5, a redshift putatively beyond the epoch of reionization when the damping wings of the neutral hydrogen of the intergalactic medium is capable of severely attenuating Lyalpha emission. By comparing the Lyalpha luminosity functions at z approximate to 5.7 and z approximate to 6.5, we infer that the intergalactic medium may remain largely reionized from the local universe out to z approximate to 6.5. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. CALTECH, Space Radiat Lab, Pasadena, CA 91125 USA. Columbia Univ, Dept Astron, New York, NY 10027 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Stern, D (reprint author), CALTECH, Jet Prop Lab, MS 169-506, Pasadena, CA 91109 USA. EM stern@zwolfkinder.jpl.nasa.gov NR 75 TC 71 Z9 71 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 JAN 20 PY 2005 VL 619 IS 1 BP 12 EP 18 DI 10.1086/426423 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KA UT WOS:000226508900002 ER PT J AU Shang, ZH Brotherton, MS Green, RF Kriss, GA Scott, J Quijano, JK Blaes, O Hubeny, I Hutchings, J Kaiser, ME Koratkar, A Oegerle, W Zheng, W AF Shang, ZH Brotherton, MS Green, RF Kriss, GA Scott, J Quijano, JK Blaes, O Hubeny, I Hutchings, J Kaiser, ME Koratkar, A Oegerle, W Zheng, W TI Quasars and the big blue bump SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : active; galaxies : nuclei; quasars : general; ultraviolet : general ID ACTIVE GALACTIC NUCLEI; DIGITAL SKY SURVEY; SMALL-MAGELLANIC-CLOUD; THIN ACCRETION DISKS; X-RAY PROPERTIES; NON-LTE MODELS; ENERGY-DISTRIBUTION; BLACK-HOLE; OBSERVATIONAL APPEARANCE; INTERSTELLAR EXTINCTION AB We investigate the ultraviolet-to-optical spectral energy distributions of 17 active galactic nuclei (AGNs) using quasi-simultaneous spectrophotometry spanning 900-9000 Angstrom (rest frame). We employ data from the Far Ultraviolet Spectroscopic Explorer, the Hubble Space Telescope, and the 2.1 m telescope at Kitt Peak National Observatory. Taking advantage of the short-wavelength coverage, we are able to study the so-called big blue bump, the region in which the energy output peaks, in detail. Most objects exhibit a spectral break around 1100 Angstrom. Although this result is formally associated with large uncertainty for some objects, there is strong evidence in the data that the far-ultraviolet spectral region is below the extrapolation of the near-ultraviolet-optical slope, indicating a spectral break around 1100 Angstrom. We compare the behavior of our sample to those of non-LTE thin-disk models covering a range in black hole mass, Eddington ratio, disk inclination, and other parameters. The distribution of ultraviolet-optical spectral indices redward of the break and far-ultraviolet indices shortward of the break are in rough agreement with the models. However, we do not see a correlation between the far-ultraviolet spectral index and the black hole mass, as seen in some accretion disk models. We argue that the observed spectral break is intrinsic to AGNs, although intrinsic reddening as well as Comptonization can strongly affect the far-ultraviolet spectral index. We make our data available online in digital format. C1 Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. Kitt Peak Natl Observ, Natl Opt Astron Observ, Tucson, AZ 85726 USA. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Natl Res Council Canada, Herzberg Inst Astrophys, Victoria, BC V9E 2E7, Canada. Johns Hopkins Univ, Ctr Astrophys Sci, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21250 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. RP Shang, ZH (reprint author), Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA. EM shang@uwyo.edu; mbrother@uwyo.edu RI Oegerle, William/C-9070-2012 NR 48 TC 92 Z9 94 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 JAN 20 PY 2005 VL 619 IS 1 BP 41 EP 59 DI 10.1086/426134 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KA UT WOS:000226508900005 ER PT J AU Collins, NR Kraemer, SB Crenshaw, DM Ruiz, J Deo, R Bruhweiler, FC AF Collins, NR Kraemer, SB Crenshaw, DM Ruiz, J Deo, R Bruhweiler, FC TI Physical conditions in the narrow-line region of Markarian 3. I. Observational results SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (Markarian 3); galaxies : Seyfert; line : formation ID ACTIVE GALACTIC NUCLEI; TELESCOPE IMAGING SPECTROGRAPH; SEYFERT-2 GALAXY MARKARIAN-3; LARGE-MAGELLANIC-CLOUD; INTERNATIONAL-ULTRAVIOLET-EXPLORER; INTER-STELLAR EXTINCTION; LONG-SLIT SPECTROSCOPY; EMISSION-LINE; NGC 4151; INTERSTELLAR EXTINCTION AB We use Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS) long-slit low-resolution spectroscopy from 1150 to 10300 8 to study the physical conditions in the narrow-line region (NLR) of the Seyfert 2 galaxy Markarian 3. We find from the He II lambda1640/lambda4686 line ratio and the Balmer decrement that the extinction within Mrk 3 along the line of sight to the NLR is best characterized by an LMC-type extinction curve. We observe an extinction gradient increasing from west to east along the STIS slit (at position angle 71degrees measured east from north) in both line and continuum emission. We infer from this gradient that the host galaxy disk is tilted toward the observer in the east: the line of sight to the eastern emission-line cone intersects more dust in the plane of the galaxy than that to the western cone. From emission-line diagnostics we find that the NLR gas is photoionized by the hidden active galactic nucleus continuum and that its density decreases with increasing distance from the center. We model the observed continuum as a combination of reddened host galaxy light from an old stellar population, reddened H+ and He+2 recombination continua, and less reddened scattered light from the central engine with spectral index alpha = 1 (L-nu proportional to nu(-alpha)). The host galaxy-to-scattered light ratio is estimated to be 3:1 at 8125 Angstrom in a 0."1 x 1."8 aperture. Using a two-component power-law model for the ionizing continuum (alpha = 2 for 13.6 eV < E < 0.2 keV and alpha = 1 for 0.2 keV < E < 50 keV), we find that the covering factor ( normalized for our observation aperture) of the NLR gas is greater than 0.7%. We estimate that the amount of intrinsic nonionizing UV continuum scattered into our line of sight is 0.04%. This is consistent with our estimate of the scattering fraction for broad C IV lambdalambda1548, 1551 emission. C1 Catholic Univ Amer, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. NASA, Goddard Space Flight Ctr, Greenbelt, MD 20771 USA. Georgia State Univ, Dept Phys & Astron, Astron Off, Atlanta, GA 30303 USA. RP Collins, NR (reprint author), Catholic Univ Amer, Inst Astrophys & Computat Sci, Washington, DC 20064 USA. EM collins@stis.gsfc.nasa.gov; stiskraemer@yancey.gsfc.nasa.gov; crenshaw@chara.gsu.edu; ruiz@yancey.gsfc.nasa.gov; deo@chara.gsu.edu; fredb@iacs.gsfc.nasa.gov NR 70 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 JAN 20 PY 2005 VL 619 IS 1 BP 116 EP 133 DI 10.1086/426314 PN 1 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KA UT WOS:000226508900011 ER PT J AU Bhattacharyya, S Strohmayer, TE Miller, MC Markwardt, CB AF Bhattacharyya, S Strohmayer, TE Miller, MC Markwardt, CB TI Constraints on neutron star parameters from burst oscillation light curves of the accreting millisecond pulsar XTE J1814-338 SO ASTROPHYSICAL JOURNAL LA English DT Article DE equation of state; radiative transfer; relativity; stars : neutron; X-rays : binaries; X-rays : bursts ID X-RAY-BURSTS; GENERAL-RELATIVITY; BRIGHTNESS OSCILLATIONS; COHERENT OSCILLATIONS; SAX J1808.4-3658; KS 1731-260; HOT-SPOTS; EVOLUTION; BINARY; COMPACTNESS AB Detailed modeling of the millisecond brightness oscillations during thermonuclear bursts from low-mass X-ray binaries can provide important information about neutron star structure. Until now, the implementation of this idea has not been entirely successful, largely because of the negligible harmonic content in burst oscillation light curves. However, the recent discovery of nonsinusoidal burst oscillation light curves from the accreting millisecond pulsar XTE J1814 - 338 has changed this situation. We therefore, for the first time, make use of this opportunity to constrain neutron star parameters. In our detailed study of the light curves of 22 bursts, we fit the burst oscillation light curves with fully general relativistic models that include light bending and frame dragging for light curve calculation and numerically compute the structure of neutron stars using realistic equations of state. We find that for our model and parameter grid values, at the 90% confidence level, Rc(2)/GM > 4.2 for the neutron star in XTE J1814 - 338. We also find that the photons from the thermonuclear flash come out through the layers of accreted matter under conditions consistent with Thomson scattering and show that the secondary companion is a hydrogen-burning main-sequence star with possible bloating ( probably due to X-ray heating). C1 Univ Maryland, Dept Astron, College Pk, MD 20742 USA. NASA, Goddard Space Flight Ctr, High Energy Astrophys Lab, Greenbelt, MD 20771 USA. RP Univ Maryland, Dept Astron, College Pk, MD 20742 USA. EM sudip@astro.umd.edu; stroh@clarence.gsfc.nasa.gov; miller@astro.umd.edu; craigm@milkyway.gsfc.nasa.gov NR 37 TC 61 Z9 61 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 JAN 20 PY 2005 VL 619 IS 1 BP 483 EP 491 DI 10.1086/426383 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KA UT WOS:000226508900037 ER PT J AU Yurchyshyn, V Yashiro, S Abramenko, V Wang, H Gopalswamy, N AF Yurchyshyn, V Yashiro, S Abramenko, V Wang, H Gopalswamy, N TI Statistical distributions of speeds of coronal mass ejections SO ASTROPHYSICAL JOURNAL LA English DT Article DE Sun : corona; Sun : coronal mass ejections (CMEs) ID SOLAR-FLARES; ACCELERATION; AVALANCHE; EVENT; CME AB We studied the distribution of plane-of-sky speeds determined for 4315 coronal mass ejections (CMEs) detected by the Large Angle and Spectrometric Coronagraph Experiment on board the Solar and Heliospheric Observatory (SOHO LASCO). We found that the speed distributions for accelerating and decelerating events are nearly identical and to a good approximation they can be fitted with a single lognormal distribution. This finding implies that, statistically, there is no physical distinction between the accelerating and the decelerating events. The lognormal distribution of the CME speeds suggests that the same driving mechanism of a nonlinear nature is acting in both slow and fast dynamical types of CMEs. C1 Big Bear Solar Observ, Big Bear City, CA 92314 USA. Catholic Univ Amer, Ctr Solar Phys & Space Weather, Washington, DC 20064 USA. Crimean Astrophys Observ, UA-98409 Nauchnyi, Crimea, Ukraine. New Jersey Inst Technol, Ctr Solar Res, Newark, NJ 07102 USA. NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RP Yurchyshyn, V (reprint author), Big Bear Solar Observ, Big Bear City, CA 92314 USA. RI Gopalswamy, Nat/D-3659-2012; OI Gopalswamy, Nat/0000-0001-5894-9954 NR 31 TC 48 Z9 51 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 20 PY 2005 VL 619 IS 1 BP 599 EP 603 DI 10.1086/426129 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KA UT WOS:000226508900047 ER PT J AU Arnouts, S Schiminovich, D Ilbert, O Tresse, L Milliard, B Treyer, M Bardelli, S Budavari, T Wyder, TK Zucca, E Le Fevre, O Martin, DC Vettolani, G Adami, C Arnaboldi, M Barlow, T Bianchi, L Bolzonella, M Bottini, D Byun, YI Cappi, A Charlot, S Contini, T Donas, J Forster, K Foucaud, S Franzetti, P Friedman, PG Garilli, B Gavignaud, I Guzzo, L Heckman, TM Hoopes, C Iovino, A Jelinsky, P Le Brun, V Lee, YW Maccagni, D Madore, BF Malina, R Marano, B Marinoni, C McCracken, HJ Mazure, A Meneux, B Merighi, R Morrissey, P Neff, S Paltani, S Pello, R Picat, JP Pollo, A Pozzetti, L Radovich, M Rich, RM Scaramella, R Scodeggio, M Seibert, M Siegmund, O Small, T Szalay, AS Welsh, B Xu, CK Zamorani, G Zanichelli, A AF Arnouts, S Schiminovich, D Ilbert, O Tresse, L Milliard, B Treyer, M Bardelli, S Budavari, T Wyder, TK Zucca, E Le Fevre, O Martin, DC Vettolani, G Adami, C Arnaboldi, M Barlow, T Bianchi, L Bolzonella, M Bottini, D Byun, YI Cappi, A Charlot, S Contini, T Donas, J Forster, K Foucaud, S Franzetti, P Friedman, PG Garilli, B Gavignaud, I Guzzo, L Heckman, TM Hoopes, C Iovino, A Jelinsky, P Le Brun, V Lee, YW Maccagni, D Madore, BF Malina, R Marano, B Marinoni, C McCracken, HJ Mazure, A Meneux, B Merighi, R Morrissey, P Neff, S Paltani, S Pello, R Picat, JP Pollo, A Pozzetti, L Radovich, M Rich, RM Scaramella, R Scodeggio, M Seibert, M Siegmund, O Small, T Szalay, AS Welsh, B Xu, CK Zamorani, G Zanichelli, A TI The GALEX VIMOS-VLT Deep Survey measurement of the evolution of the 1500 luminosity function SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; galaxies : evolution; galaxies : luminosity function, mass function; ultraviolet : galaxies ID STAR-FORMING GALAXIES; HIGH-REDSHIFT; FIELD-SOUTH; ULTRAVIOLET; DENSITY AB We present the first measurement of the galaxy luminosity function (LF) at 1500 Angstrom in the range 0.2 less than or equal to z less than or equal to 1.2 based on Galaxy Evolution Explorer VIMOS-VLT Deep Survey observations (similar to1000 spectroscopic redshifts for galaxies with NUV less than or equal to 24.5) and at higher z using existing data sets. Our main results are summarized as follows: (1) Luminosity evolution is observed with DeltaM(*) similar to -2.0 mag between z = 0 and z = 1 and DeltaM(*) similar to -1.0 mag between z = 1 and z = 3. This confirms that the star formation activity was significantly higher in the past. (2) The LF slopes vary in the range -1.2 greater than or equal to alpha greater than or equal to -1.65, with a marginally significant hint of increase at higher z. (3) We split the sample in three rest-frame (B-I) intervals, providing an approximate spectral type classification: Sb - Sd, Sd - Irr, and unobscured starbursts. We find that the bluest class evolves less strongly in luminosity than the two other classes. On the other hand, their number density increases sharply with z (similar to 15% in the local universe to similar to55% at z similar to1), while that of the reddest classes decreases. C1 Lab Astrophys Marseille, F-13376 Marseille 12, France. Columbia Univ, Dept Astron, New York, NY 10027 USA. CALTECH, Pasadena, CA 91125 USA. Osservatorio Astron Bologna, INAF, I-40127 Bologna, Italy. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Inst Radioastron, INAF, I-40129 Bologna, Italy. Osserv Astron Capodimonte, INAF, I-80131 Naples, Italy. Univ Bologna, Dept Astron, I-40127 Bologna, Italy. Inst Astrofis Spaziale & Fis Cosmica, INAF, I-20133 Milan, Italy. Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. Max Planck Inst Astrophys, D-85741 Garching, Germany. Inst Astrophys, UMR 7095, F-75014 Paris, France. Observ Midi Pyrenees, Astrophys Lab, F-31400 Toulouse, France. Osserv Astron Brera, INAF, I-20121 Milan, Italy. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. CALTECH, NASA IPAC, Pasadena, CA 91125 USA. RP Arnouts, S (reprint author), Lab Astrophys Marseille, BP 8, F-13376 Marseille 12, France. EM stephane.arnouts@oamp.fr RI Pello, Roser/G-4754-2010; Le Fevre, Olivier/G-7389-2011; Merighi, Roberto/O-9360-2015; Cappi, Alberto/O-9391-2015; Zucca, Elena/O-9396-2015; Bolzonella, Micol/O-9495-2015; Bardelli, Sandro/O-9369-2015 OI Merighi, Roberto/0000-0003-2490-1834; Cappi, Alberto/0000-0002-9200-7167; Zucca, Elena/0000-0002-5845-8132; Bolzonella, Micol/0000-0003-3278-4607; Bardelli, Sandro/0000-0002-8900-0298 NR 27 TC 146 Z9 146 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 JAN 20 PY 2005 VL 619 IS 1 BP L43 EP L46 DI 10.1086/426733 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300011 ER PT J AU Bianchi, L Thilker, DA Burgarella, D Friedman, PG Hoopes, CG Boissier, S de Paz, AG Barlow, TA Byun, YI Donas, J Forster, K Heckman, TM Jelinsky, PN Lee, YW Madore, BF Malina, RF Martin, DC Milliard, B Morrissey, P Neff, SG Rich, RM Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK AF Bianchi, L Thilker, DA Burgarella, D Friedman, PG Hoopes, CG Boissier, S de Paz, AG Barlow, TA Byun, YI Donas, J Forster, K Heckman, TM Jelinsky, PN Lee, YW Madore, BF Malina, RF Martin, DC Milliard, B Morrissey, P Neff, SG Rich, RM Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK TI Recent star formation in nearby galaxies from Galaxy Evolution Explorer imaging: M101 and M51 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (M51, M101); galaxies : star clusters; ultraviolet : galaxies ID STELLAR POPULATION; ULTRAVIOLET; SCALE; RESOLUTION; FIELD AB The Galaxy Evolution Explorer (GALEX) Nearby Galaxies Survey is providing deep far-UV and near-UV imaging for a representative sample of galaxies in the local universe. We present early results for M51 and M101, from GALEX UV imaging and Sloan Digital Sky Survey optical data in five bands. The multiband photometry of compact stellar complexes in M101 is compared to population synthesis models, to derive ages, reddening, reddening-corrected luminosities, and current/initial masses. The GALEX UV photometry provides a complete census of young compact complexes on a approximate to160 pc scale. A galactocentric gradient of the far-UV/near-UV color indicates younger stellar populations toward the outer parts of the galaxy disks, the effect being more pronounced in M101 than in M51. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Lab Astrophys Marseille, F-13376 Marseille 12, France. CALTECH, Pasadena, CA 91125 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Bianchi, L (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. EM bianchi@pha.jhu.edu; dthilker@pha.jhu.edu; denis.burgarella@oamp.fr; friedman@srl.caltech.edu; hoopes@pha.jhu.edu; agpaz@ipac.caltech.edu; tab@srl.caltech.edu; byun@obs.yonsei.ac.kr; krl@srl.caltech.edu; heckman@pha.jhu.edu; patrick@srl.caltech.edu; ywlee@obs.yonsei.ac.kr; barry@ipac.caltech.edu; roger.malina@oamp.fr; cmartin@srl.caltech.edu; bruno.milliard@oamp.fr; patrick@srl.caltech.edu; neff@stars.gsfc.nasa.gov; rmr@astro.ucla.edu; ds@srl.caltech.edu; ossy@ssl.berkeley.edu; tas@srl.caltech.edu; bwelsh@ssl.berkeley.edu; wyder@srl.caltech.edu RI Gil de Paz, Armando/J-2874-2016; OI Gil de Paz, Armando/0000-0001-6150-2854; malina, roger/0000-0003-3399-3865 NR 20 TC 40 Z9 40 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 JAN 20 PY 2005 VL 619 IS 1 BP L71 EP L74 DI 10.1086/422685 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300018 ER PT J AU Bianchi, L Seibert, M Zheng, W Thilker, DA Friedman, PG Wyder, TK Donas, J Barlow, TA Byun, YI Forster, K Heckman, TM Jelinsky, PN Lee, YW Madore, BF Malina, RF Martin, DC Milliard, B Morrissey, P Neff, SG Rich, RM Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY AF Bianchi, L Seibert, M Zheng, W Thilker, DA Friedman, PG Wyder, TK Donas, J Barlow, TA Byun, YI Forster, K Heckman, TM Jelinsky, PN Lee, YW Madore, BF Malina, RF Martin, DC Milliard, B Morrissey, P Neff, SG Rich, RM Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY TI Classification and characterization of objects from the Galaxy Evolution Explorer Survey and the Sloan Digital Sky Survey SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : statistics; quasars : general; stars : statistics; surveys ID STELLAR; SPECTRUM AB We use the Galaxy Evolution Explorer (GALEX) Medium Imaging Survey (MIS) and All-sky Imaging Survey (AIS) data available in the first internal release, matched to the Sloan Digital Sky Survey (SDSS) catalogs in the overlapping regions, to classify objects by comparing the multiband photometry to model colors. We show an example of the advantage of such broad wavelength coverage (GALEX far-UV and near-UV, SDSS ugriz) in classifying objects and augmenting the existing samples and catalogs. From the MIS ( AIS) sample over an area of 75 (92) deg(2), we select a total of 1736 (222) QSO candidates at redshifts less than 2, significantly extending the number of fainter candidates and moderately increasing the number of bright objects in the SDSS list of spectroscopically confirmed QSOs. Numerous hot stellar objects are also revealed by the UV colors, as expected. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. CALTECH, Pasadena, CA 91125 USA. Lab Astrophys Marseille, F-13376 Marseille, France. Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Bianchi, L (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. EM bianchi@pha.jhu.edu; mseibert@srl.caltech.edu; zheng@pha.jhu.edu; dthilker@pha.jhu.edu; friedman@srl.caltech.edu; wyder@srl.caltech.edu; denis.burgarella@oamp.fr; tab@srl.caltech.edu; byun@obs.yonsei.ac.kr; krl@srl.caltech.edu; heckman@pha.jhu.edu; patj@ssl.berkeley.edu; ywlee@obs.yonsei.ac.kr; barry@ipac.caltech.edu; roger.malina@oamp.fr; cmartin@srl.caltech.edu; bruno.milliard@oamp.fr; patrick@srl.caltech.edu; neff@stars.gsfc.nasa.gov; rmr@astro.ucla.edu; ds@srl.caltech.edu; ossy@ssl.berkeley.edu; tas@srl.caltech.edu; szalay@pha.jhu.edu; bwelsh@ssl.berkeley.edu OI malina, roger/0000-0003-3399-3865 NR 21 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 JAN 20 PY 2005 VL 619 IS 1 BP L27 EP L30 DI 10.1086/423710 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300007 ER PT J AU Boissier, S de Paz, AG Madore, BF Boselli, A Buat, V Burgarella, D Friedman, PG Barlow, TA Bianchi, L Byun, YI Donas, J Forster, K Heckman, TM Jelinsky, PN Lee, YW Malina, RF Martin, DC Milliard, B Morrissey, P Neff, SG Rich, RM Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK AF Boissier, S de Paz, AG Madore, BF Boselli, A Buat, V Burgarella, D Friedman, PG Barlow, TA Bianchi, L Byun, YI Donas, J Forster, K Heckman, TM Jelinsky, PN Lee, YW Malina, RF Martin, DC Milliard, B Morrissey, P Neff, SG Rich, RM Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK TI Extinction radial profiles of M83 from GALEX ultraviolet imaging SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; galaxies : individual (M83); ultraviolet : galaxies ID SPECTRAL ENERGY-DISTRIBUTION; STAR-FORMATION HISTORY; STARBURST GALAXIES; FORMING GALAXIES; DISC GALAXIES; DUST CONTENT; GAS; NGC-891 AB We use the far-UV (FUV) and near-UV images of M83 obtained by the Galaxy Evolution Explorer (GALEX) to compute the radial profile of the UV spectral slope in the star-forming disk. We briefly present a model of its chemical evolution, which allows us to obtain realistic intrinsic properties of the stellar populations. Using corollary data, we also compute the profiles of Halpha/Hbeta and total-IR/FUV ratios. Both the data and model are used to estimate and compare the extinction gradients at the FUV wavelength obtained from these various indicators. We discuss the implications for the determination of the star formation rate. C1 Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Lab Astrophys Marseille, F-13376 Marseille 12, France. CALTECH, Pasadena, CA 91125 USA. Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Boissier, S (reprint author), Observ Carnegie Inst Washington, 813 Santa Barbara St, Pasadena, CA 91101 USA. EM boissier@ociw.edu; agpaz@ociw.edu; madore@ociw.edu; alessandro.boselli@oamp.fr; veronique.buat@oamp.fr; denis.burgarella@oamp.fr; friedman@srl.caltech.edu; tab@srl.caltech.edu; bianchi@skysrv.pha.jhu.edu; byun@csa.yonsei.ac.kr; jose.donas@oamp.fr; krl@srl.caltech.edu; heckman@pha.jhu.edu; patj@ssl.berkeley.edu; ywlee@csa.yonsei.ac.kr; roger.malina@oamp.fr; cmartin@srl.caltech.edu; bruno.milliard@oamp.fr; patrick@srl.caltech.edu; neff@stars.gsfc.nasa.gov; rmr@astro.ucla.edu; ds@srl.caltech.edu; ossy@ssl.berkeley.edu; tas@srl.caltech.edu; szalay@pha.jhu.edu; pwelsh@ssl.berkeley.edu; wyder@srl.caltech.edu RI Gil de Paz, Armando/J-2874-2016; OI Gil de Paz, Armando/0000-0001-6150-2854; malina, roger/0000-0003-3399-3865 NR 27 TC 32 Z9 32 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 JAN 20 PY 2005 VL 619 IS 1 BP L83 EP L86 DI 10.1086/423668 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300021 ER PT J AU Buat, V Iglesias-Paramo, J Seibert, M Burgarella, D Charlot, S Martin, DC Xu, CK Heckman, TM Boissier, S Boselli, A Barlow, T Bianchi, L Byun, YI Donas, J Forster, K Friedman, PG Jelinski, P Lee, YW Madore, BF Malina, R Milliard, B Morissey, P Neff, S Rich, M Schiminovitch, D Siegmund, O Small, T Szalay, AS Welsh, B Wyder, TK AF Buat, V Iglesias-Paramo, J Seibert, M Burgarella, D Charlot, S Martin, DC Xu, CK Heckman, TM Boissier, S Boselli, A Barlow, T Bianchi, L Byun, YI Donas, J Forster, K Friedman, PG Jelinski, P Lee, YW Madore, BF Malina, R Milliard, B Morissey, P Neff, S Rich, M Schiminovitch, D Siegmund, O Small, T Szalay, AS Welsh, B Wyder, TK TI Dust attenuation in the nearby universe: A comparison between galaxies selected in the ultraviolet and in the far-infrared SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; galaxies : photometry; galaxies : stellar content; infrared : galaxies; ultraviolet : galaxies ID STAR-FORMATION HISTORY; STARBURST GALAXIES; FORMING GALAXIES; FORMATION RATES; LOCAL UNIVERSE; VIRGO CLUSTER; DISK GALAXIES; EXTINCTION; LUMINOSITY; ABSORPTION AB We compare the dust attenuation properties of two samples of galaxies purely selected in the Galaxy Evolution Explorer (GALEX) near-ultraviolet band (NUV; 1750 - 2750 Angstrom, lambda(mean) = 2310 Angstrom) and in the far-infrared (FIR) at 60 mum. These samples are built using the GALEX and IRAS sky surveys over similar to 600 deg(2). The NUV-selected sample contains 95 galaxies detected down to NUV = 16 mag (AB system). Eighty-three galaxies in this sample are spiral or irregular, and only two of them are not detected at 60 mum. The FIR-selected sample is built from the IRAS PSCz survey, which is complete down to 0.6 Jy. Among the 163 sources, we select 118 star-forming galaxies that are well measured by IRAS; all but one are detected in NUV, and 14 galaxies are not detected in the far-ultraviolet band (FUV; 1350 - 1750 Angstrom, lambda(mean) = 1530 Angstrom). The dust-to-ultraviolet (NUV and FUV) flux ratio is calibrated to estimate the dust attenuation at both wavelengths. The median value of the attenuation in NUV is found to be similar to1 mag for the NUV-selected sample, versus similar to2 mag for the FIR-selected one. Within both samples, the dust attenuation is found to correlate with the luminosity of the galaxies. Almost all the NUV-selected galaxies and two-thirds of the FIR-selected sample exhibit a lower dust attenuation than expected from the tight relation found previously for starburst galaxies between dust attenuation and the slope of the ultraviolet continuum. The situation is reversed for the remaining third of the FIR-selected galaxies: their extinction is higher than that deduced from their color and the relation for starbursts. C1 Lab Astrophys Marseille, F-13012 Marseille, France. CALTECH, Space Astrophys Lab, Pasadena, CA 91125 USA. Inst Astrophys, CNRS, F-75014 Paris, France. Max Planck Inst Astrophys, D-85748 Garching, Germany. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Buat, V (reprint author), Lab Astrophys Marseille, BP 8, F-13012 Marseille, France. EM veronique.buat@oamp.fr OI malina, roger/0000-0003-3399-3865; Iglesias-Paramo, Jorge/0000-0003-2726-6370 NR 31 TC 215 Z9 215 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 JAN 20 PY 2005 VL 619 IS 1 BP L51 EP L54 DI 10.1086/423241 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300013 ER PT J AU Budavari, T Szalay, AS Charlot, S Seibert, M Wyder, TK Arnouts, S Barlow, TA Bianchi, L Byun, YI Donas, J Forster, K Friedman, PG Heckman, TM Jelinsky, PN Lee, YW Madore, BF Malina, RF Martin, DC Milliard, B Morrissey, P Neff, SG Rich, RM Schiminovich, D Siegmund, OHW Small, T Treyer, MA Welsh, B AF Budavari, T Szalay, AS Charlot, S Seibert, M Wyder, TK Arnouts, S Barlow, TA Bianchi, L Byun, YI Donas, J Forster, K Friedman, PG Heckman, TM Jelinsky, PN Lee, YW Madore, BF Malina, RF Martin, DC Milliard, B Morrissey, P Neff, SG Rich, RM Schiminovich, D Siegmund, OHW Small, T Treyer, MA Welsh, B TI The ultraviolet luminosity function of GALEX galaxies at photometric redshifts between 0.07 and 0.25 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : luminosity function, mass function; galaxies : photometry; surveys; ultraviolet : galaxies ID DIGITAL SKY SURVEY; STAR-FORMATION; DENSITY; SPACE AB We present measurements of the UV galaxy luminosity function and the evolution of luminosity density from Galaxy Evolution Explorer (GALEX) observations matched to the Sloan Digital Sky Survey (SDSS). We analyze galaxies in the Medium Imaging Survey overlapping the SDSS First Data Release, with a total coverage of 44 deg(2). Using the combined GALEX + SDSS photometry, we compute photometric redshifts and study the luminosity function in three redshift shells between z = 0.07 and 0.25. The Schechter function fits indicate that the faint-end slope alpha is consistent with -1.1 at all redshifts, but the characteristic UV luminosity M-* brightens by 0.2 mag from z = 0.07 to 0.25. In the lowest redshift bin, early- and late-type galaxies are studied separately, and we confirm that red galaxies tend to be brighter and have a shallower slope alpha than blue ones. The derived luminosity densities are consistent with other GALEX results based on a local spectroscopic sample from the Two-Degree Field, and the evolution follows the trend reported by deeper studies. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Inst Astrophys, CNRS, F-75014 Paris, France. CALTECH, Pasadena, CA 91125 USA. Lab Astrophys Marseille, F-13376 Marseille 12, France. Yonsei Univ, Ctr Space Astrophya, Seoul 120749, South Korea. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Columbia Univ, Dept Astron, New York, NY 10027 USA. RP Budavari, T (reprint author), Johns Hopkins Univ, Dept Phys & Astron, 3701 San Martin Dr, Baltimore, MD 21218 USA. OI malina, roger/0000-0003-3399-3865 NR 23 TC 34 Z9 34 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 JAN 20 PY 2005 VL 619 IS 1 BP L31 EP L34 DI 10.1086/423319 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300008 ER PT J AU Burgarella, D Buat, V Small, T Barlow, TA Boissier, S de Paz, AG Heckman, TM Madore, BF Martin, DC Rich, RM Bianchi, L Byun, YI Donas, J Forster, K Friedman, PG Jelinsky, PN Lee, YW Malina, RF Milliard, B Morrissey, P Neff, SG Schiminovich, D Siegmund, OHW Szalay, AS Welsh, BY Wyder, TK AF Burgarella, D Buat, V Small, T Barlow, TA Boissier, S de Paz, AG Heckman, TM Madore, BF Martin, DC Rich, RM Bianchi, L Byun, YI Donas, J Forster, K Friedman, PG Jelinsky, PN Lee, YW Malina, RF Milliard, B Morrissey, P Neff, SG Schiminovich, D Siegmund, OHW Szalay, AS Welsh, BY Wyder, TK TI Galaxy Evolution Explorer ultraviolet spectroscopy and deep imaging of luminous infrared galaxies in the European Large-Area ISO Survey S1 field SO ASTROPHYSICAL JOURNAL LA English DT Article DE dust, extinction; galaxies : starburst; infrared : galaxies; ultraviolet : galaxies ID STAR-FORMATION; STARBURST GALAXIES; DUST; DENSITY AB The European Large-Area ISO Survey (ELAIS) S1 field was observed by the Galaxy Evolution Explorer (GALEX) in both its Wide Spectroscopic and Deep Imaging Survey modes. This field was previously observed by the Infrared Space Observatory, and we made use of the catalog of multiwavelength data published by the ELAIS consortium to select galaxies common to the two samples. Among the 959 objects with GALEX spectroscopy, 88 are present in the ELAIS catalog and 19 are galaxies with an optical spectroscopic redshift. The distribution of redshifts covers the range 0 < z < 1.6. The selected galaxies have bolometric IR luminosities 10 < log L-IR < 13 (deduced from the 15 mum flux using ISOCAM), which means that we cover a wide range of IR galaxies from normal to ultraluminous IR galaxies. The mean (sigma) UV luminosity (not corrected for extinction) amounts to log lambdaL(1530) = 9.8(0.6)L-. for the low-z (z less than or equal to 0.35) sample. The UV slope beta (assuming f(lambda) proportional to lambda(beta)) correlates with the GALEX FUV - NUV color if the sample is restricted to galaxies below z < 0.1. Taking advantage of the UV and IR data, we estimate the dust attenuation from the IR/UV ratio and compare it to the UV slope β. We find that it is not possible to uniquely estimate the dust attenuation from β for our sample of galaxies. These galaxies are highly extinguished with a median value A(FUV) = 2.7 +/- 0.8. Once the dust correction is applied, the UV- and IR-based star formation rates correlate. For the closest galaxy with the best quality spectrum, we see a feature consistent with being produced by a bump near 220 nm in the attenuation curve. C1 Lab Astrophys Marseille, Observ Astron Marseille Prov, F-13376 Marseille 12, France. CALTECH, Pasadena, CA 91125 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. CALTECH, NASA IPAC Extragalact Database, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90065 USA. Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Burgarella, D (reprint author), Lab Astrophys Marseille, Observ Astron Marseille Prov, F-13376 Marseille 12, France. EM denis.burgarella@oamp.fr; veronique.buat@oamp.fr; tas@srl.caltech.edu; tab@srl.caltech.edu; boissier@ociw.edu; agpaz@ipac.caltech.edu; heckman@adcam.pha.jhu.edu; barry@ipac.caltech.edu; cmartin@srl.caltech.edu; rmr@astro.ucla.edu; bianchi@skyrv.pha.jhu.edu; byun@csa.yonsei.ac.kr; jose.donas@oamp.fr; krl@srl.caltech.edu; friedman@srl.caltech.edu; patj@ssl.berkeley.edu; ywlee@csa.yonsei.ac.kr; roger.malina@oamp.fr; bruno.milliard@oamp.fr; patrick@srlcaltech.edu; neff@cobblr.gsfc.nasa.gov; ds@srl.caltech.edu; ossy@ssl.berkeley.edu; szalay@tardis.pha.jhu.edu; bwelsh@ssl.berkeley.edu; wyder@srl.caltech.edu RI Gil de Paz, Armando/J-2874-2016; OI Gil de Paz, Armando/0000-0001-6150-2854; malina, roger/0000-0003-3399-3865 NR 22 TC 16 Z9 16 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 JAN 20 PY 2005 VL 619 IS 1 BP L63 EP L66 DI 10.1086/423894 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300016 ER PT J AU de Paz, AG Madore, BF Sohn, YJ Lee, YW Seibert, M Rich, RM Bianchi, L Barlow, TA Byun, YI Donas, J Forster, K Friedman, PG Heckman, TM Jelinsky, P Malina, RF Martin, DC Milliard, B Morrissey, P Neff, SG Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK AF de Paz, AG Madore, BF Sohn, YJ Lee, YW Seibert, M Rich, RM Bianchi, L Barlow, TA Byun, YI Donas, J Forster, K Friedman, PG Heckman, TM Jelinsky, P Malina, RF Martin, DC Milliard, B Morrissey, P Neff, SG Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK TI Galaxy Evolution Explorer observations of the ultraviolet surface brightness and color profiles of the local group elliptical galaxy M32 (NGC 221) SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : elliptical and lenticular, cD; galaxies : fundamental parameters; galaxies : individual (M32); Local Group; ultraviolet : galaxies ID PHOTOMETRY; POPULATIONS AB M32, the compact elliptical galaxy companion to the Andromeda spiral galaxy, has been imaged by the Galaxy Evolution Explorer (GALEX) in two UV bands, centered at similar to1500 (far-ultraviolet [FUV]) and 2300 Angstrom (near- ultraviolet). The imaging data have been carefully decomposed so as to properly account for the complicated background contamination from the disk of M31. We have derived the surface brightness and color profiles finding a slightly positive color gradient of Delta(FUV - B)/Delta log r = +0.15 +/- 0.03 within one effective radius. Earlier data from the Ultraviolet Imaging Telescope suggested that M32 had an extremely large (negative) FUV-optical color gradient [Delta(FUV - B)/Delta log r < -2], inverted with respect to the majority of gradients seen in giant elliptical galaxies. Our new results show that despite its very low UV upturn, M32 has similar UV properties to those observed in luminous elliptical galaxies. C1 Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. CALTECH, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. Lab Astrophys Marseille, F-13376 Marseille 12, France. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP de Paz, AG (reprint author), Observ Carnegie Inst Washington, 813 Santa Barbara St, Pasadena, CA 91101 USA. EM agpaz@ociw.edu; sohnyj@csa.yonsei.ac.kr; ywlee@csa.yonsei.ac.kr; mseibert@srl.caltech.edu; rmr@astro.ucla.edu; bianchi@skysrv.pha.jhu.edu; tab@srl.caltech.edu; byun@csa.yonsei.ac.kr; jose.donas@astrsp-mrs.fr; krl@srl.caltech.edu; friedman@srl.caltech.edu; heckman@pha.jhu.edu; patj@ssl.berkeley.edu; roger.malina@astrsp-mrs.fr; cmartin@srl.caltech.edu; bruno.milliard@astrsp-mrs.fr; patrick@srl.caltech.edu; neff@stars.gsfc.nasa.gov; ds@srl.caltech.edu; ossy@ssl.berkeley.edu; tas@srl.caltech.edu; szalay@pha.jhu.edu; bwelsh@ssl.berkeley.edu; wyder@srl.caltech.edu RI Gil de Paz, Armando/J-2874-2016; OI Gil de Paz, Armando/0000-0001-6150-2854; malina, roger/0000-0003-3399-3865 NR 19 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 JAN 20 PY 2005 VL 619 IS 1 BP L115 EP L118 DI 10.1086/422470 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300029 ER PT J AU Heckman, TM Hoopes, CG Seibert, M Martin, DC Salim, S Rich, RM Kauffmann, G Charlot, S Barlow, TA Bianchi, L Byun, YI Donas, J Forster, K Friedman, PG Jelinsky, PN Lee, YW Madore, BF Malina, RF Milliard, B Morrissey, PF Neff, SG Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK AF Heckman, TM Hoopes, CG Seibert, M Martin, DC Salim, S Rich, RM Kauffmann, G Charlot, S Barlow, TA Bianchi, L Byun, YI Donas, J Forster, K Friedman, PG Jelinsky, PN Lee, YW Madore, BF Malina, RF Milliard, B Morrissey, PF Neff, SG Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK TI The properties of ultraviolet-luminous galaxies at the current epoch SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : general; galaxies : starburst; ultraviolet : galaxies ID DIGITAL SKY SURVEY; STAR-FORMING GALAXIES; LYMAN-BREAK GALAXIES; REDSHIFT GALAXIES; STELLAR MASS; DATA RELEASE; EVOLUTION; DENSITY AB We have used the first matched set of Galaxy Evolution Explorer (GALEX) and Sloan Digital Sky Survey (SDSS) data to investigate the properties of a sample of 74 nearby (z < 0.3) galaxies with far-ultraviolet luminosities greater than 2 x 10(10) L-., chosen to overlap the luminosity range of typical high-z Lyman break galaxies (LBGs). GALEX deep surveys have shown that ultraviolet-luminous galaxies (UVLGs) similar to these are the fastest evolving component of the UV galaxy population. Model fits to the combined GALEX and SDSS photometry yield typical FUV extinctions in UVLGs of 0.5 - 2 mag ( similar to LBGs and less luminous GALEX-selected galaxies). The implied star formation rates are SFR &SIM; 3 3-30 M-. yr(-1). This overlaps the range of SFRs for LBGs. We find a strong inverse correlation between galaxy mass and FUV surface brightness, and on this basis we divide the sample into "large" and "compact" UVLGs. The large UVLGs are relatively massive (M* &SIM; 10(11) M-.) late-type disk galaxies forming stars at a rate similar to their past average (M-*/SFR &SIM; t(Hubble)). They are metal rich (approximately solar), have intermediate optical-UV colors (FUV - r &SIM; 2-3), and about a third host a type 2 (obscured) active galactic nucleus. In contrast, the compact UVLGs have half-light radii of a few kpc or less (similar to LBGs). They are relatively low-mass galaxies (M-* &SIM; 10(10) M-.) with typical velocity dispersions of 60 - 150 km s(-1). They span a range in metallicity from &SIM;0.3 to 1 times solar, have blue optical-UV colors (FUV - r &SIM; 0.5-2), and are forming stars at a rate sufficient to build the present galaxy in &SIM; 1 - 2 Gyr. In all these respects they appear similar to the LBG population. These "living fossils" may therefore provide an opportunity for detailed investigation of the physical processes occurring in typical star-forming galaxies in the early universe. C1 Johns Hopkins Univ, Ctr Astrophys Sci, Dept Phys & Astron, Baltimore, MD 21218 USA. CALTECH, Div Phys Math & Astron, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Max Planck Inst Astrophys, D-85748 Garching, Germany. Inst Astrophys, F-75014 Paris, France. Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. Lab Astrophys Marseille, F-13376 Marseille 12, France. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. CALTECH, NASA IPAC Extragalact Database, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Heckman, TM (reprint author), Johns Hopkins Univ, Ctr Astrophys Sci, Dept Phys & Astron, 3400 N Charles St, Baltimore, MD 21218 USA. OI malina, roger/0000-0003-3399-3865 NR 30 TC 112 Z9 112 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 JAN 20 PY 2005 VL 619 IS 1 BP L35 EP L38 DI 10.1086/425979 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300009 ER PT J AU Hibbard, JE Bianchi, L Thilker, DA Rich, RM Schiminovich, D Xu, CK Neff, SG Seibert, M Lauger, S Burgarella, D Barlow, TA Byun, YI Donas, J Forster, K Friedman, PG Heckman, TM Jelinsky, PN Lee, YW Madore, BF Malina, RF Martin, DC Milliard, B Morrissey, P Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK AF Hibbard, JE Bianchi, L Thilker, DA Rich, RM Schiminovich, D Xu, CK Neff, SG Seibert, M Lauger, S Burgarella, D Barlow, TA Byun, YI Donas, J Forster, K Friedman, PG Heckman, TM Jelinsky, PN Lee, YW Madore, BF Malina, RF Martin, DC Milliard, B Morrissey, P Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK TI Ultraviolet morphology and star formation in the tidal tails of NGC 4038/39 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : individual (NGC 4038, NGC 4039); galaxies : interactions; galaxies : ISM; galaxies : starburst; intergalactic medium; ultraviolet : galaxies ID INTERACTING GALAXIES; STELLAR POPULATIONS; DWARF CANDIDATES; ADVANCED CAMERA; ANTENNAE; CLUSTERS; RESOLUTION; SAMPLE AB We present Galaxy Evolution Explorer far-ultraviolet (1530 Angstrom) and near-ultraviolet (2310 Angstrom) observations of the archetypal merging system NGC 4038/39, "the Antennae." Both tails are relatively bright in the UV, especially in the vicinity of the tidal dwarf galaxy candidates at the end of the southern tail. The UV light generally falls within the optically delineated tails, although the UV light is considerably more structured, with a remarkably similar morphology to the tidal H I. The UV colors suggest that there has been continuing star formation within the tidal tails, even outside the previously studied tidal dwarf regions. Within the inner disk regions, there are interesting UV features that appear to be related to the extended soft X-ray loops and halo recently discovered by Chandra. C1 Natl Radio Astron Observ, Charlottesville, VA 22903 USA. Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. CALTECH, Pasadena, CA 91125 USA. Columbia Univ, Dept Astron, New York, NY 10025 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Lab Astrophys Marseille, F-13376 Marseille 12, France. Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. RP Hibbard, JE (reprint author), Natl Radio Astron Observ, 520 Edgemont Rd, Charlottesville, VA 22903 USA. EM jhibbard@nrao.edu OI malina, roger/0000-0003-3399-3865 NR 29 TC 45 Z9 45 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 JAN 20 PY 2005 VL 619 IS 1 BP L87 EP L90 DI 10.1086/423244 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300022 ER PT J AU Hoopes, CG Heckman, TM Strickland, DK Seibert, M Madore, BF Rich, RM Bianchi, L de Paz, AG Burgarella, D Thilker, DA Friedman, PG Barlow, TA Byun, YI Donas, J Forster, K Jelinsky, PN Lee, YW Malina, RF Martin, DC Milliard, B Morrissey, PF Neff, SG Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK AF Hoopes, CG Heckman, TM Strickland, DK Seibert, M Madore, BF Rich, RM Bianchi, L de Paz, AG Burgarella, D Thilker, DA Friedman, PG Barlow, TA Byun, YI Donas, J Forster, K Jelinsky, PN Lee, YW Malina, RF Martin, DC Milliard, B Morrissey, PF Neff, SG Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK TI GALEX observations of the ultraviolet halos of NGC 253 and M82 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : halos; galaxies : individual (M82, NGC 253); galaxies : starburst; ISM : jets and outflows; ultraviolet : galaxies ID X-RAY-EMISSION; LYMAN BREAK GALAXIES; DIFFUSE IONIZED-GAS; H-ALPHA EMISSION; STARBURST GALAXIES; STAR-FORMATION; CHANDRA OBSERVATIONS; GALACTIC SUPERWINDS; DUST; EXTINCTION AB We present Galaxy Evolution Explorer (GALEX) images of the prototypical edge-on starburst galaxies M82 and NGC 253. Our initial analysis is restricted to the complex of ultraviolet (UV) filaments in the starburst-driven outflows in the galaxy halos. The UV luminosities in the halo are too high to be provided by continuum and line emission from shock-heated or photoionized gas, except perhaps in the brightest filaments in M82, suggesting that most of the UV light is the stellar continuum of the starburst scattered into our line of sight by dust in the outflow. This interpretation agrees with previous results from optical imaging polarimetry in M82. The observed luminosity of the halo UV light is less than or similar to0.1% of the bolometric luminosity of the starburst. The morphology of the UV filaments in both galaxies shows a high degree of spatial correlation with Halpha and X-ray emission. This indicates that these outflows contain cold gas and dust, some of which may be vented into the intergalactic medium (IGM). UV light is seen in the "Halpha cap" 11 kpc north of M82. If this cap is a result of the wind fluid running into a preexisting gas cloud, the gas cloud contains dust and is not primordial in nature, but was probably stripped from M82 or M81. If starburst winds efficiently expel dust into the IGM, this could have significant consequences for the observation of cosmologically distant objects. C1 Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. CALTECH, Pasadena, CA 91125 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. CALTECH, NASA, IPAC Extragalact Database, Pasadena, CA 91125 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. Lab Astrophys Marseille, F-13376 Marseille 12, France. Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Hoopes, CG (reprint author), Johns Hopkins Univ, Dept Phys & Astron, Homewood Campus, Baltimore, MD 21218 USA. RI Gil de Paz, Armando/J-2874-2016; OI Gil de Paz, Armando/0000-0001-6150-2854; malina, roger/0000-0003-3399-3865 NR 36 TC 57 Z9 57 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 JAN 20 PY 2005 VL 619 IS 1 BP L99 EP L102 DI 10.1086/423032 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300025 ER PT J AU Lee, YW Ree, CH Rich, RM Deharveng, JM Sohn, YJ Rey, SC Yi, SK Yoon, SJ Bianchi, L Lee, JW Seibert, M Barlow, TA Byun, YI Donas, J Forster, K Friedman, PG Heckman, TM Jee, MJ Jelinsky, PN Kim, SW Madore, BF Malina, RF Martin, DC Milliard, B Morrissey, P Neff, SG Rhee, J Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK AF Lee, YW Ree, CH Rich, RM Deharveng, JM Sohn, YJ Rey, SC Yi, SK Yoon, SJ Bianchi, L Lee, JW Seibert, M Barlow, TA Byun, YI Donas, J Forster, K Friedman, PG Heckman, TM Jee, MJ Jelinsky, PN Kim, SW Madore, BF Malina, RF Martin, DC Milliard, B Morrissey, P Neff, SG Rhee, J Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK TI The look-back time evolution of far-ultraviolet flux from elliptical galaxies: The Fornax Cluster and A2670 SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : stellar content; ultraviolet : galaxies ID HORIZONTAL-BRANCH STARS; EMISSION; PHOTOMETRY; RADIATION; SPECTRA; CATALOG; Z=0.33 AB In order to investigate the origin of the far-UV (FUV) flux from the early-type galaxies, the Galaxy Evolution Explorer is collecting the UV data for the elliptical-rich clusters at moderate redshifts (z < 0.2) where the dominant FUV source is predicted to be hot horizontal-branch (HB) stars and their post-HB progeny. Here we present our first result for the early-type galaxies in A2670 at z = 0.076. Compared to NGC 1399, a nearby giant elliptical galaxy in the Fornax Cluster, it appears that the rest-frame FUV - V color of the giant elliptical galaxies gets redder by &SIM;0.7 mag at the distance of A2670 (z = 0.076; look-back time &AP; 1.0 Gyr). Although a detailed comparison with the models is postponed until more cluster data are accumulated, it is interesting to note that this value is consistent with the variation predicted by the population synthesis models where the mean temperature of HB stars declines rapidly with increasing look-back time. C1 Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. Yonsei Univ, Dept Astron, Seoul 120749, South Korea. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Lab Astrophys Marseille, F-13376 Marseille 12, France. CALTECH, Pasadena, CA 91125 USA. Chungnam Natl Univ, Dept Astron & Space Sci, Taejon 305764, South Korea. Univ Oxford, Dept Phys, Oxford OX1 3RH, England. Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. Sejong Univ, Dept Astron & Space Sci, Seoul 143747, South Korea. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. CALTECH, NASA, IPAC Extragalact Database, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. RP Lee, YW (reprint author), Yonsei Univ, Ctr Space Astrophys, 134 Shinchon, Seoul 120749, South Korea. EM ywlee@csa.yonsei.ac.kr; chr@csa.yonsei.ac.kr OI Ree, Chang Hee/0000-0001-8986-112X NR 26 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 JAN 20 PY 2005 VL 619 IS 1 BP L103 EP L106 DI 10.1086/422503 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300026 ER PT J AU Martin, DC Seibert, M Buat, R Iglesias-Paramo, J Barlow, TA Bianchi, L Byun, YI Donas, J Forster, K Friedman, PG Heckman, TM Jelinsky, PN Lee, YW Madore, BF Malina, RF Milliard, B Morrissey, PF Neff, SG Rich, RM Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK AF Martin, DC Seibert, M Buat, R Iglesias-Paramo, J Barlow, TA Bianchi, L Byun, YI Donas, J Forster, K Friedman, PG Heckman, TM Jelinsky, PN Lee, YW Madore, BF Malina, RF Milliard, B Morrissey, PF Neff, SG Rich, RM Schiminovich, D Siegmund, OHW Small, T Szalay, AS Welsh, BY Wyder, TK TI The star formation rate function of the local universe SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : fundamental parameters; galaxies : luminosity function, mass function; infrared : galaxies; ultraviolet : galaxies ID STELLAR MASS FUNCTIONS; LUMINOSITY FUNCTIONS; FORMING GALAXIES; IRAS OBSERVATIONS; FORMATION HISTORY; HIGH-REDSHIFT; CATALOG AB We have derived the bivariate luminosity function for the far-ultraviolet (1530 Angstrom) and far-infrared (60 mum). We use matched GALEX and IRAS data, and redshifts from NED and the PSCz survey. We have derived a total star formation luminosity function phi(L-tot), with L-tot = L-FUV + L-FIR. Using these, we determined the cosmic "star formation rate" (SFR) function and density for the local universe. The total SFR function phi(L-tot) is fitted very well by a lognormal distribution over 5 decades of luminosity. We find that the bivariate luminosity function phi(L-LUV, L-FIR) shows a bimodal behavior, with L-FIR tracking L-FUV for L-tot < 10(10) L-., and L-FUV saturating at &SIM;10(10) L-., while L-tot &SIM; L-FIR for higher luminosities. We also calculate the SFR density and compare it with other tot FIR measurements. C1 CALTECH, Space Astrophys Lab, Pasadena, CA 91125 USA. Lab Astrophys Marseille, F-13376 Marseille 12, France. Johns Hopkins Univ, Ctr Astrophys Sci, Baltimore, MD 21218 USA. Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Martin, DC (reprint author), CALTECH, Space Astrophys Lab, Mail Stop 405-47,1200 E Calif Blvd, Pasadena, CA 91125 USA. EM cmartin@srl.caltech.edu OI malina, roger/0000-0003-3399-3865; Iglesias-Paramo, Jorge/0000-0003-2726-6370 NR 31 TC 58 Z9 58 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 20 PY 2005 VL 619 IS 1 BP L59 EP L62 DI 10.1086/425496 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300015 ER PT J AU Martin, DC Fanson, J Schiminovich, D Morrissey, P Friedman, PG Barlow, TA Conrow, T Grange, R Jelinsky, PN Milliard, B Siegmund, OHW Bianchi, L Byun, YI Donas, J Forster, K Heckman, TM Lee, YW Madore, BF Malina, RF Neff, SG Rich, RM Small, T Surber, F Szalay, AS Welsh, B Wyder, TK AF Martin, DC Fanson, J Schiminovich, D Morrissey, P Friedman, PG Barlow, TA Conrow, T Grange, R Jelinsky, PN Milliard, B Siegmund, OHW Bianchi, L Byun, YI Donas, J Forster, K Heckman, TM Lee, YW Madore, BF Malina, RF Neff, SG Rich, RM Small, T Surber, F Szalay, AS Welsh, B Wyder, TK TI The Galaxy Evolution Explorer: A space ultraviolet survey mission SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies : evolution; galaxies : general; space vehicles : instruments; surveys; ultraviolet : galaxies; ultraviolet : general ID STAR-FORMATION HISTORY; HIGH-REDSHIFT; TELESCOPE; INSTRUMENT; LUMINOSITY; RESOLUTION; INTENSITY; SATELLITE; DENSITY AB We give an overview of the Galaxy Evolution Explorer (GALEX), a NASA Explorer Mission launched on 2003 April 28. GALEX is performing the first space UV sky survey, including imaging and grism surveys in two bands (1350 - 1750 and 1750 - 2750 Angstrom). The surveys include an all-sky imaging survey (m(AB) similar or equal to 20.5), a medium imaging survey of 1000 deg(2) (m(AB) similar or equal to 23), a deep imaging survey of 100 deg(2) (m(AB) similar or equal to 25), and a nearby galaxy survey. Spectroscopic (slitless) grism surveys (R = 100-200) are underway with various depths and sky coverage. Many targets overlap existing or planned surveys in other bands. We will use the measured UV properties of local galaxies, along with corollary observations, to calibrate the relationship of the UV and global star formation rate in local galaxies. We will apply this calibration to distant galaxies discovered in the deep imaging and spectroscopic surveys to map the history of star formation in the universe over the redshift range 0 < z < 2 and probe the physical drivers of star formation in galaxies. The GALEX mission includes a guest investigator program, supporting the wide variety of programs made possible by the first UV sky survey. C1 CALTECH, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Lab Astrophys Marseille, F-13376 Marseille, France. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Yonsei Univ, Ctr Space Astrophya, Seoul 120749, South Korea. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. CALTECH, NASA IPAC Extragalact Database, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Martin, DC (reprint author), CALTECH, MS 405-47,1200 E Calif Blvd, Pasadena, CA 91125 USA. NR 50 TC 879 Z9 881 U1 3 U2 13 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 JAN 20 PY 2005 VL 619 IS 1 BP L1 EP L6 DI 10.1086/426387 PN 2 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300001 ER PT J AU Morrissey, P Schiminovich, D Barlow, TA Martin, DC Blakkolb, B Conrow, T Cooke, B Erickson, K Fanson, J Friedman, PG Grange, R Jelinsky, PN Lee, SC Liu, DK Mazer, A McLean, R Milliard, B Randall, D Schmitigal, W Sen, A Siegmund, OHW Surber, F Vaughan, A Viton, M Welsh, BY Bianchi, L Byun, YI Donas, J Forster, K Heckman, TM Lee, YW Madore, BF Malina, RF Neff, SG Rich, RM Small, T Szalay, AS Wyder, TK AF Morrissey, P Schiminovich, D Barlow, TA Martin, DC Blakkolb, B Conrow, T Cooke, B Erickson, K Fanson, J Friedman, PG Grange, R Jelinsky, PN Lee, SC Liu, DK Mazer, A McLean, R Milliard, B Randall, D Schmitigal, W Sen, A Siegmund, OHW Surber, F Vaughan, A Viton, M Welsh, BY Bianchi, L Byun, YI Donas, J Forster, K Heckman, TM Lee, YW Madore, BF Malina, RF Neff, SG Rich, RM Small, T Szalay, AS Wyder, TK TI The on-orbit performance of the Galaxy Evolution Explorer SO ASTROPHYSICAL JOURNAL LA English DT Article DE space vehicles : instruments; surveys; telescopes; ultraviolet : general AB We report the first year's on-orbit performance results for the Galaxy Evolution Explorer (GALEX), a NASA Small Explorer that is performing a survey of the sky in two ultraviolet bands. The instrument comprises a 50 cm diameter modified Ritchey-Chretien telescope with a 1degrees.25 field of view, selectable imaging and objective-grism spectroscopic modes, and an innovative optical system with a thin-film multilayer dichroic beam splitter that enables simultaneous imaging by a pair of photon-counting, microchannel-plate, delay-line readout detectors. Initial measurements demonstrate that GALEX is performing well, meeting its requirements for resolution, efficiency, astrometry, bandpass definition, and survey sensitivity. C1 CALTECH, Space Astrophys Lab, Pasadena, CA 91125 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Lab Astrophys Marseille, F-13376 Marseille, France. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Yonsei Univ, Ctr Space Astrophys, Seoul 120749, South Korea. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. CALTECH, Ctr Infrared Proc & Anal, Pasadena, CA 91125 USA. NASA, Goddard Space Flight Ctr, Astron & Solar Phys Lab, Greenbelt, MD 20771 USA. Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. RP Morrissey, P (reprint author), CALTECH, Space Astrophys Lab, Mail Stop 405-47,1200 E Calif Blvd, Pasadena, CA 91125 USA. EM patrick@srl.caltech.edu NR 6 TC 231 Z9 232 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 JAN 20 PY 2005 VL 619 IS 1 BP L7 EP L10 DI 10.1086/424734 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 890KE UT WOS:000226509300002 ER EF