FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Bailey, SM Cornforth, MN Kurimasa, A Chen, DJ Goodwin, EH AF Bailey, SM Cornforth, MN Kurimasa, A Chen, DJ Goodwin, EH TI Strand-specific postreplicative processing of mammalian telomeres SO SCIENCE LA English DT Article ID HUMAN-CHROMOSOMES; DNA; END; TRF2; FUSIONS; LENGTH AB Telomeres are specialized nucleoprotein structures that stabilize the ends of linear eukaryotic chromosomes. In mammalian cells, abrogation of telomeric repeat binding factor TRF2 or DNA-dependent protein kinase (DNA-PK) activity causes end-to-end chromosomal fusion, thus establishing an essential role for these proteins in telomere function. Here we show that TRF2-mediated endcapping occurs after telomere replication. The postreplicative requirement for TRF2 and DNA-PKcs, the catalytic subunit of DNA-PK, is confined to only half of the telomeres, namely, those that were produced by leading-strand DNA synthesis. These results demonstrate a crucial difference in postrepticative processing of telomeres that is linked to their mode of replication. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87544 USA. Univ Texas, Med Branch, Dept Radiat Oncol, Galveston, TX 77550 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Cell & Mol Biol, Berkeley, CA 94720 USA. RP Goodwin, EH (reprint author), Los Alamos Natl Lab, Biosci Div, POB 1663, Los Alamos, NM 87544 USA. FU NCI NIH HHS [CA50519, CA76260]; NIA NIH HHS [AG-917709] NR 20 TC 186 Z9 193 U1 0 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 28 PY 2001 VL 293 IS 5539 BP 2462 EP 2465 DI 10.1126/science.1062560 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 476PD UT WOS:000171237200050 PM 11577237 ER PT J AU Lyman, JL Jensen, RJ AF Lyman, JL Jensen, RJ TI Chemical reactions occurring during direct solar reduction of CO2 SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article; Proceedings Paper CT 5th International Conference on Carbon Dioxide Utilization (ICCDU V) CY SEP 05-10, 1999 CL KARLSRUHE, GERMANY DE photochemistry; chemical kinetics; carbon dioxides; carbon monoxide; water reactions; solar reactions; carbon dioxide utilization AB At high temperatures carbon dioxide may absorb solar radiation and react to form carbon monoxide and molecular oxygen. The CO2 so produced, may be converted by well-established means to a combustible fuel, such as methanol. We intend to make a future demonstration of the solar reduction of CO2 based on these processes. This paper, however, addresses only the problem of preserving, or even enhancing, the initial photolytic CO2 by quenching the hot gas with colder H2O or CO2. We present model calculations with a reaction mechanism used extensively in other calculations. If a CO2 gas stream is heated and photolyzed by intense solar radiation and then allowed to cool slowly, it will react back to the initial CO2 by a series of elementary chemical reactions. The back reaction to CO2 can be terminated with the rapid addition of CO2 water, or a mixture. Calculations show that a three-fold quench with pure CO2 will stop the reactions and preserve over 90% of the initial photolytic CO. We find that water has one of two effects. It can either increase the CO level, or it can catalyze the recombination of O and CO to CO2 The gas temperature is the determining factor. If the quench gas is not sufficient to keep the temperature below approximately 1100 K, a chain-branching reaction dominates and the reaction to CO2 occurs. If the temperature stays below that level a chain terminating reaction dominates and the CO is increased. The former case occurs below approximately a fourfold quench with a water/CO2 mixture. The later case occurs when the quench is greater than fourfold. We conclude that CO2, H2O, or a mixture may quench the hot gas stream photolyzed by solar radiation and preserve the photolytic CO. ((C)) 2001 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Renewable Energy Corp, Los Alamos, NM 87544 USA. RP Lyman, JL (reprint author), Los Alamos Natl Lab, MS J567, Los Alamos, NM 87545 USA. NR 4 TC 12 Z9 12 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD SEP 28 PY 2001 VL 277 IS 1-3 BP 7 EP 14 DI 10.1016/S0048-9697(01)00829-4 PG 8 WC Environmental Sciences SC Environmental Sciences & Ecology GA 476JF UT WOS:000171222000002 PM 11589409 ER PT J AU Voss, KJ Welton, EJ Quinn, PK Frouin, R Miller, M Reynolds, RM AF Voss, KJ Welton, EJ Quinn, PK Frouin, R Miller, M Reynolds, RM TI Aerosol optical depth measurements during the Aerosols99 experiment SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SHIPBOARD; TABLES; INDEX; OZONE; AIR AB The Aerosols99 cruise took place during the period from January 14 to February 8, 1999, on the R/V Ronald Brown. The cruise track was almost a straight line in the southeast direction from Norfolk, Virginia, to Cape Town, South Africa, and afforded the opportunity to sample several different aerosol regimes over the North and South Atlantic. Handheld sunphotometers, a shadowband radiometer (FRSR), and a LIDAR were used to measure the aerosol optical depth (AOD) during the cruise. The AOD and angstrom exponent a (spectral dependence of the AOD) varied strongly between regimes. Maritime regions typically had AOD (500 nm) of approximately 0.10 +/- 0.03, with a around 0.3 +/- 0.3. An African dust event was encountered in which the AOD (500 nm) averaged 0.29 +/- 0.05 with an alpha of 0.36 +/- 0.13. At the Intertropical Convergence Zone (ITCZ), no measurements were obtained because of cloudiness; however, after the ITCZ we encountered a biomass burning aerosol with high average AOD (500 nm) of 0.36 +/- 0.13, and a high alpha (0.88 +/- 0.30). Farther south the aerosol went back to the low levels of a typical marine aerosol. C1 Univ Miami, Dept Phys, Miami, FL 33146 USA. Univ Maryland, Goddard Earth Sci & Technol Ctr, Baltimore, MD 21228 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Univ Washington, Joint Inst Study Atmosphere & Oceans, Seattle, WA 98195 USA. Univ Calif San Diego, Inst Oceanog Sci, La Jolla, CA 92037 USA. Brookhaven Natl Lab, Dept Environm Sci, Upton, NY 11973 USA. RP Voss, KJ (reprint author), Univ Miami, Dept Phys, Miami, FL 33146 USA. EM voss@physics.miami.edu RI Welton, Ellsworth/A-8362-2012; Voss, Kenneth /A-5328-2013; Quinn, Patricia/R-1493-2016 OI Voss, Kenneth /0000-0002-7860-5080; Quinn, Patricia/0000-0003-0337-4895 NR 16 TC 20 Z9 21 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 27 PY 2001 VL 106 IS D18 BP 20811 EP 20819 DI 10.1029/2000JD900783 PG 9 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 476FV UT WOS:000171216300014 ER PT J AU Gaffney, KJ Miller, AD Liu, SH Harris, CB AF Gaffney, KJ Miller, AD Liu, SH Harris, CB TI Femtosecond dynamics of electrons photoinjected into organic semiconductors at aromatic-metal interfaces SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID IMAGE-POTENTIAL STATES; PHOTOELECTRON-SPECTROSCOPY; 2-PHOTON PHOTOEMISSION; INJECTION; AG(111); ANTHRACENE; SURFACES; BENZENE; HYDROCARBONS; NAPHTHALENE AB The layer dependent evolution of the unoccupied electronic structure and electron dynamics at the naphthalene/ Ag(1 1 1) and the anthracene/Ag(1 1 1) interfaces have been investigated with femtosecond time and angle resolved two photon photoemission. With the exception of the peaks observed for the naphthalene monolayer, all excitations in the two photon photoemission spectra fit a hydrogenic progression, substantiating their assignment as image potential states. The monolayer excitations for naphthalene cannot be assigned as either image potential states or electron affinity (EA) levels, but rather as hybridized EA/image potential states. The binding energies and lifetimes of the image potential states for naphthalene and anthracene exhibit two significant differences that demonstrate the tremendous variation in the coupling between the image potential and the EA levels of naphthalene and those of anthracene. First., the binding energies at the naphthalene/ Ag(1 1 1) interface exceed those of the anthracene/Ag(1 1 1) interface, even though anthracene has a larger EA than naphthalene. Second, the 1. 1 ps lifetime for the n = 1 image potential state for a bilayer of anthracene exceeds the n = 1 lifetime for a bilayer bf naphthalene by a factor of 30. Theoretical calculations demonstrate that the transition from a near resonant to a nonresonant interaction between the image potential and the adsorbate EA levels causes these significant variations in binding energies and lifetimes. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Harris, CB (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 39 TC 30 Z9 30 U1 2 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 27 PY 2001 VL 105 IS 38 BP 9031 EP 9039 DI 10.1021/jp010931c PG 9 WC Chemistry, Physical SC Chemistry GA 476EX UT WOS:000171214200003 ER PT J AU Miyabe, K Guiochon, G AF Miyabe, K Guiochon, G TI Correlation between surface diffusion and molecular diffusion in reversed-phase liquid chromatography SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID COLUMN RADIAL HETEROGENEITY; LINEAR CHROMATOGRAPHY; LATERAL DIFFUSION; RESTRICTED DIFFUSION; ACTIVATED CARBON; SILICA SURFACES; ADSORPTION; MODEL; DEPENDENCE; INTERFACE AB Surface diffusion data previously measured for different compounds, mobile phase solvents, stationary phases, and temperatures in reversed-phase liquid chromatography (RPLC) were reevaluated to derive information related to the mechanism and characteristic features of surface diffusion. First, a comparison of the surface diffusion coefficient (D-s) and the corresponding molecular diffusivity (D-m) suggests that the dependence of D-s on the RPLC conditions is a consequence of that of D-m. There is a correlation between surface diffusion coefficients and molecular diffusivity. Second, we showed that D-s correlates with the adsorption equilibrium constant (K) and the isosteric heat of adsorption (Q(st)). These two parameters represent the intensity of the adsorptive interactions between the sample molecules and the surface of the stationary phase. Finally, the ratio Ds/Dm increases with decreasing K and -Q(st) and D-s becomes of the same order of magnitude as D-m when the adsorptive interactions become small. These results imply that surface diffusion should be regarded as molecular diffusion restricted by the influence of adsorptive interactions. Other information on surface diffusion was also obtained. The value of D,. extrapolated at Q(st) = 0 is not equal to D-s The difference between the two coefficients depends on the experimental conditions, e.g., the nature of the organic modifier in the mobile phase or the surface density of the C-18 alkyl ligand on the stationary phase. Our results demonstrate that surface diffusion is fundamentally related to molecular diffusion. C1 Toyama Univ, Fac Educ, Toyama 9308555, Japan. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Guiochon, G (reprint author), Toyama Univ, Fac Educ, 3190 Gofuku, Toyama 9308555, Japan. NR 47 TC 21 Z9 21 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 27 PY 2001 VL 105 IS 38 BP 9202 EP 9209 DI 10.1021/jp010563c PG 8 WC Chemistry, Physical SC Chemistry GA 476EX UT WOS:000171214200027 ER PT J AU LeSar, R AF LeSar, R TI An analytic approach describing structural effects on the properties of molecular fluids SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID VIBRATIONAL FREQUENCY-SHIFTS; NITROGEN; TEMPERATURES; PRESSURES AB An analytic approach is used to evaluate how the angular structure of a molecular fluid contributes to its thermodynamic properties, The average interactions (energy, forces, etc.) between molecules are first expressed as integrals over a spherical-harmonic expansion of the pair distribution function of the fluid. Angularly averaged interactions for systems described by site-site representations of the intermolecular potentials are then developed. Specifically, homonuclear diatomic molecules described by two-site potential are considered in this paper. These results are used to examine the role that fluid structure plays in determining the average energy, pressure, and forces on a molecule, using as comparison simulation data on dense, fluid nitrogen. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP LeSar, R (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI LeSar, Richard/G-1609-2012 NR 16 TC 0 Z9 0 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 27 PY 2001 VL 105 IS 38 BP 9287 EP 9296 DI 10.1021/jp0036994 PG 10 WC Chemistry, Physical SC Chemistry GA 476EX UT WOS:000171214200037 ER PT J AU Bearden, IG Boggild, H Boissevain, J Christiansen, P Conin, L Dodd, J Erazmus, B Esumi, S Fabjan, CW Ferenc, D Fields, DE Franz, A Gaardhoje, J Hansen, AG Hansen, O Hardtke, D van Hecke, H Holzer, EB Humanic, TJ Hummel, P Jacak, BV Jayanti, R Kaimi, K Kaneta, M Kohama, T Kopytine, M Leltchouk, M Ljubicic, A Lorstad, B Maeda, N Martin, L Medvedev, A Murray, M Ohnishi, H Paic, G Pandey, SU Piuz, F Pluta, J Polychronakos, V Potekhin, M Poulard, G Reichold, D Sakaguchi, A Schmidt-Sorensen, J Simon-Gillo, J Sondheim, W Sugitate, T Sullivan, JP Sumi, Y Willis, WJ Wolf, KL Xu, N Zachary, DS AF Bearden, IG Boggild, H Boissevain, J Christiansen, P Conin, L Dodd, J Erazmus, B Esumi, S Fabjan, CW Ferenc, D Fields, DE Franz, A Gaardhoje, J Hansen, AG Hansen, O Hardtke, D van Hecke, H Holzer, EB Humanic, TJ Hummel, P Jacak, BV Jayanti, R Kaimi, K Kaneta, M Kohama, T Kopytine, M Leltchouk, M Ljubicic, A Lorstad, B Maeda, N Martin, L Medvedev, A Murray, M Ohnishi, H Paic, G Pandey, SU Piuz, F Pluta, J Polychronakos, V Potekhin, M Poulard, G Reichold, D Sakaguchi, A Schmidt-Sorensen, J Simon-Gillo, J Sondheim, W Sugitate, T Sullivan, JP Sumi, Y Willis, WJ Wolf, KL Xu, N Zachary, DS CA NA44 Collaboration TI One and two-dimensional analysis of 3 pi correlations measured in Pb plus Pb interactions SO PHYSICS LETTERS B LA English DT Article DE three-particle correlations; 3-body; interferometry; HBT; heavy-ion collisions; CERN SPS ID RELATIVISTIC NUCLEAR COLLISIONS; BOSE-EINSTEIN CORRELATIONS; HEAVY-ION COLLISIONS; PION INTERFEROMETRY; 2-PION AB pi (-)pi (-)pi (-) correlations from Pb+Pb collisions at 158 GeV/c per nucleon are presented as measured by the focusing spectrometer of the NA44 experiment at CERN. The three-body effect is found to be stronger for Pb+Pb than for S+Pb. The two-dimensional three-particle correlation function is also measured and the longitudinal extension of the source is larger than the transverse extension. (C) 2001 Published by Elsevier Science B.V. C1 Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Phys Nucl Lab, F-44072 Nantes, France. Columbia Univ, New York, NY 10027 USA. Hiroshima Univ, Higashihiroshima 739, Japan. CERN, CH-1211 Geneva 23, Switzerland. Rudjer Boskovic Inst, Zagreb, Croatia. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Lund Univ, S-22362 Lund, Sweden. Texas A&M Univ, College Stn, TX 77843 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Warsaw Univ Technol, PL-00662 Warsaw, Poland. RP Bearden, IG (reprint author), Niels Bohr Inst, Blegdamsvej 17, DK-2100 Copenhagen, Denmark. RI Bearden, Ian/M-4504-2014 OI Bearden, Ian/0000-0003-2784-3094 NR 23 TC 31 Z9 31 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD SEP 27 PY 2001 VL 517 IS 1-2 BP 25 EP 31 DI 10.1016/S0370-2693(01)00978-9 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 476GY UT WOS:000171218900005 ER PT J AU Chiang, WT Tabakin, F Lee, TSH Saghai, B AF Chiang, WT Tabakin, F Lee, TSH Saghai, B TI Coupled-channel study of gamma p -> K+ Lambda SO PHYSICS LETTERS B LA English DT Article DE kaon photoproduction; coupled channel; final-state interaction; meson-baryon interaction ID KAON PHOTOPRODUCTION; ELECTROMAGNETIC PRODUCTION; PION-PHOTOPRODUCTION; MESON; MODEL; SCATTERING; STRANGENESS; CONSTANTS; DYNAMICS; PHYSICS AB A coupled-channel (CC) approach has been developed to investigate kaon photoproduction on the nucleon. In addition to direct K+ Lambda production, our CC approach accounts for strangeness production including K+ Lambda final state interactions with both pi (0) p and pi (+) n intermediate states. Calculations for the gammap --> K+ Lambda reaction have been performed, and compared with the recent data from SAPHIR, with emphasis on the CC effects. We show that the CC effects are significant at the level of inducing 20% changes on total cross sections; thereby, demonstrating the need to include piN channels to correctly describe the gammap --> K+ Lambda reaction. (C) 2001 Published by Elsevier Science B.V. C1 Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Natl Taiwan Univ, Dept Phys, Taipei 10617, Taiwan. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. CEA Saclay, Serv Phys Nucl, DSM, DAPNIA, F-91191 Gif Sur Yvette, France. RP Chiang, WT (reprint author), Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. NR 25 TC 53 Z9 53 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD SEP 27 PY 2001 VL 517 IS 1-2 BP 101 EP 108 DI 10.1016/S0370-2693(01)00945-5 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 476GY UT WOS:000171218900014 ER PT J AU Diehl, M Hiller, G AF Diehl, M Hiller, G TI Yet another way to measure gamma SO PHYSICS LETTERS B LA English DT Article ID CP-VIOLATION; DECAYS AB We show that the CKM phase 2 beta + gamma can be extracted from measurement of the time dependent rates in the decays (B) over bar (0) --> D-(*M-)+/-(-/+) and B-0 --> D-(*M-)+/-(+/-), where M = a(0), pi (1300), b(1), a(2), pi (2), rho (3). These channels have a large asymmetry between decays of (B) over bar (0) and B-0 into the same final state. Even though the branching ratios are small, their sensitivity to gamma can be competitive with decays into D-(*()) and (pi, rho, a(1)). (C) 2001 Elsevier Science B.V. All rights reserved. C1 DESY, D-22603 Hamburg, Germany. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Diehl, M (reprint author), DESY, D-22603 Hamburg, Germany. NR 20 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD SEP 27 PY 2001 VL 517 IS 1-2 BP 125 EP 128 DI 10.1016/S0370-2693(01)00979-0 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 476GY UT WOS:000171218900017 ER PT J AU Eichberg, MJ Dorta, RL Grotjahn, DB Lamottke, K Schmidt, M Vollhardt, KPC AF Eichberg, MJ Dorta, RL Grotjahn, DB Lamottke, K Schmidt, M Vollhardt, KPC TI Approaches to the synthesis of (+/-)-strychnine via the cobalt-mediated [2+2+2] cycloaddition: Rapid assembly of a classic framework SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Review ID WIELAND-GUMLICH ALDEHYDE; INTRAMOLECULAR CONJUGATE ADDITION; ASPIDOSPERMATAN-TYPE ALKALOIDS; AZA-COPE REARRANGEMENTS; ALPHA,BETA-UNSATURATED KETONES; CATALYZED SYNTHESIS; ORGANIC-SYNTHESIS; 2,3-DOUBLE BOND; ENANTIOSELECTIVE SYNTHESIS; HYDROAROMATIC COMPOUNDS AB Five synthetic approaches to racemic strychnine (1), with the cobalt-mediated [2 + 2 + 2] cycloaddition of alkynes to indoles as the key step, are described. These include the generation and attempted cyclization of macrocycle 8 and the synthesis of dihydrocarbazoles 15, 22, and 26 and their elaboration to pentacyclic structures via a conjugate addition, dipolar cycloaddition, and propellane-to-spirofused skeletal rearrangement, respectively. Finally, the successful total synthesis of 1 is discussed. The development of a short, highly convergent route (14 steps in the longest linear sequence) is highlighted by the cyclization of enynoylindole 40 with acetylene and the formal intramolecular 1,8-conjugate addition of amine 49 to form pentacycle 50. Numerous attempts toward the formation of the piperidine ring of 1 from vinyl iodide 56 were made and its successful formation via palladium-, nickel-, and radical-mediated processes is described. C1 Univ Calif Berkeley, Dept Chem, Ctr New Direct Organ Synth, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Vollhardt, KPC (reprint author), Univ Calif Berkeley, Dept Chem, Ctr New Direct Organ Synth, Berkeley, CA 94720 USA. RI Dorta, Rosa/K-2914-2014; Lamottke, Kai/J-1881-2016 OI Dorta, Rosa/0000-0002-4565-0301; Lamottke, Kai/0000-0002-3265-1057 NR 175 TC 89 Z9 90 U1 4 U2 32 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 26 PY 2001 VL 123 IS 38 BP 9324 EP 9337 DI 10.1021/ja016333t PG 14 WC Chemistry, Multidisciplinary SC Chemistry GA 475NC UT WOS:000171169700015 PM 11562215 ER PT J AU Roberts, SA Weichsel, A Qiu, Y Shelnutt, JA Walker, FA Montfort, WR AF Roberts, SA Weichsel, A Qiu, Y Shelnutt, JA Walker, FA Montfort, WR TI Ligand-induced heme ruffling and bent NO geometry in ultra-high-resolution structures of nitrophorin 4 SO BIOCHEMISTRY LA English DT Article ID NITRIC-OXIDE BINDING; RAY-DIFFRACTION DATA; RHODNIUS-PROLIXUS; BLOODSUCKING INSECT; MOLECULAR STEREOCHEMISTRY; TRANSPORT PROTEIN; CRYSTAL-STRUCTURE; COMPLEXES; H-1-NMR; CONFIGURATION AB The nitrophorins are a family of proteins that use ferric heme to transport nitric oxide (NO) from the salivary glands of blood-sucking insects to their victims, resulting in vasodilation and reduced blood coagulation. We have refined atomic resolution structures of nitrophorin 4 (NP4) from Rhodnius prolixus complexed with NO (1.08 Angstrom) and NH3 (1.15 Angstrom), yielding a highly detailed picture of the iron coordination sphere. In NP4-NO, the NO nitrogen is coordinated to iron (Fe-N distance = 1.66 Angstrom) and is somewhat bent (Fe-N-O angle = 156 degrees), with bending occurring in the same plane as the proximal histidine ring, The Fe(NO)(heme)(His) coordination geometry is unusual but consistent with an Fe(III) oxidation state that is stabilized by a highly ruffled heme. Heme ruffling occurs in both structures, apparently due to close contacts between the heme and leucines 123 and 133, but increases on binding NO even though the steric contacts have not changed. We also report the structure of NP4 in complexes with histamine (1.50 Angstrom) and imidazole (1.27 Angstrom). Unexpectedly, two mobile loops that rearrange to pack against the bound NO in NP4-NO, also rearrange in the NP4-imidazole complex. This conformational change is apparently driven by the nonpolar nature of the NO and imidazole (as bound) ligands. Taken together, the desolvation of the NO binding pocket through a change in protein conformation, and the bending of the NO moiety, possibly through protein-assisted heme ruffling, may lead to a nitrosyl-heme complex that is unusually resistant to autoreduction. C1 Univ Arizona, Dept Biochem, Tucson, AZ 85721 USA. Univ Arizona, Dept Mol Biophys, Tucson, AZ 85721 USA. Univ Arizona, Dept Chem, Tucson, AZ 85721 USA. Sandia Natl Labs, Biomol Mat & Interfaces Dept, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem, Albuquerque, NM 87131 USA. RP Montfort, WR (reprint author), Univ Arizona, Dept Biochem, Tucson, AZ 85721 USA. RI Shelnutt, John/A-9987-2009; Walker, Frances/O-4395-2016 OI Shelnutt, John/0000-0001-7368-582X; FU NHLBI NIH HHS [HL54826, HL62969] NR 47 TC 122 Z9 123 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD SEP 25 PY 2001 VL 40 IS 38 BP 11327 EP 11337 DI 10.1021/bi0109257 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 476BA UT WOS:000171205300005 PM 11560480 ER PT J AU Cook, AW Dimotakis, PE AF Cook, AW Dimotakis, PE TI Transition stages of Rayleigh-Taylor instability between miscible fluids SO JOURNAL OF FLUID MECHANICS LA English DT Article ID NUMERICAL-SIMULATION; TURBULENCE AB Direct numerical simulations (DNS) are presented of three-dimensional, Rayleigh-Taylor instability (RTI) between two incompressible, miscible fluids, with a 3:1 density ratio. Periodic boundary conditions are imposed in the horizontal directions of a rectangular domain, with no-slip top and bottom walls. Solutions are obtained for the Navier-Stokes equations, augmented by a species transport-diffusion equation, with various initial perturbations. The DNS achieved outer-scale Reynolds numbers, based on mixing-zone height and its rate of growth, in excess of 3000. Initial growth is diffusive and independent of the initial perturbations. The onset of nonlinear growth is not predicted by available linear-stability theory. Following the diffusive-growth stage, growth rates are found to depend on the initial perturbations, up to the end of the simulations. Mixing is found to be even more sensitive to initial conditions than growth rates. Taylor microscales and Reynolds numbers are anisotropic throughout the simulations. Improved collapse of many statistics is achieved if the height of the mixing zone, rather than time, is used as the scaling or progress variable. Mixing has dynamical consequences for this flow, since it is driven by the action of the imposed acceleration field on local density differences. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. CALTECH, Grad Aeronaut Labs, Pasadena, CA 91125 USA. RP Cook, AW (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 35 TC 109 Z9 109 U1 0 U2 12 PU CAMBRIDGE UNIV PRESS PI PORT CHESTER PA 110 MIDLAND AVE, PORT CHESTER, NY 10573-9863 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD SEP 25 PY 2001 VL 443 BP 69 EP 99 PG 31 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 479UM UT WOS:000171422000003 ER PT J AU Chen, HL Wu, JC Lin, TL Lin, JS AF Chen, HL Wu, JC Lin, TL Lin, JS TI Crystallization kinetics in microphase-separated poly(ethylene oxide)-block-poly(1.,4-butadiene) SO MACROMOLECULES LA English DT Article ID BUTADIENE DIBLOCK COPOLYMER; BLOCK-COPOLYMERS; BEHAVIOR; POLYMER; SCATTERING; OXIDE) AB We studied the crystallization kinetics in a diblock copolymer system exhibiting different mesophase structures in the melt. A symmetric poly(ethylene oxide)-block-poly(1,4-butadiene) (PEO-b-PB) was blended with a low molecular weight PB homopolymer to yield the block copolymer blends containing lamellar, cylindrical, and spherical PEO microdomains. The crystallization kinetics of PEO blocks in these nanoscaled microdomains was then studied by monitoring the development of crystallinity in the course of isothermal crystallization. In the lamellar melt, crystallization could occur at the normal undercooling, and its kinetics closely followed the classical Avrami model found in the spherulitic crystallization of homopolymers. Crystallinity developments in the cylindrical and spherical morphology obeyed a simple exponential function prescribed by the first-order kinetics. This first-order kinetic behavior along with the exceedingly large undercooling verified the homogeneous nucleation controlled kinetics in these two types of mesophases. Crystallization in the lamellar melt transformed the melt structure into a highly interconnected lamellar morphology due to the ability of the crystal growth fronts to repeatedly thrust into the microdomains yet to be crystallized. For the crystallization condition chosen (i.e., cooling at -5 degreesC/min from the melt), the melt structures associated with the cylindrical and spherical morphology were not totally disrupted and transformed into one-dimensionally stacked lamellae upon crystallization. The melt mesophases were not fully preserved either, suggesting that some intermediate structures may have been formed through the crystallization. C1 Natl Tsing Hua Univ, Dept Chem Engn, Hsinchu 30013, Taiwan. Natl Tsing Hua Univ, Dept Engn & Syst Sci, Hsinchu 30013, Taiwan. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Chen, HL (reprint author), Natl Tsing Hua Univ, Dept Chem Engn, Hsinchu 30013, Taiwan. NR 31 TC 131 Z9 131 U1 4 U2 25 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 25 PY 2001 VL 34 IS 20 BP 6936 EP 6944 DI 10.1021/ma010552h PG 9 WC Polymer Science SC Polymer Science GA 475ZD UT WOS:000171199300015 ER PT J AU Zhang, YM Ge, S Tang, B Koga, T Rafailovich, MH Sokolov, JC Peiffer, DG Li, Z Dias, AJ McElrath, KO Lin, MY Satija, SK Urquhart, SG Ade, H Nguyen, D AF Zhang, YM Ge, S Tang, B Koga, T Rafailovich, MH Sokolov, JC Peiffer, DG Li, Z Dias, AJ McElrath, KO Lin, MY Satija, SK Urquhart, SG Ade, H Nguyen, D TI Effect of carbon black and silica fillers in elastomer blends SO MACROMOLECULES LA English DT Article ID POLYMER MOBILITY; REFLECTIVITY; INTERFACE; DIFFUSION; RUBBER; FILMS AB The effects of carbon black and pyrogeneous silica fillers on the interfacial properties of a homopolymer [polybutadiene, (PB)] and a terpolymer [brominated poly(isobutylene-co-p-metliylstyrene), (BIMS)] are reported. Neutron reflectivity (NR) was used to study the interfacial structure. The results are complemented by scanning transmission X-ray microscopy (STXM) and lateral force microscopy (LFM), which were used to probe the morphology and surface lateral force. Small-angle neutron scattering (SANS) was used to characterize the size and surface properties of the filler aggregates in elastomers. Our results show that the interfacial behavior of PB/BIMS is more sensitive to carbon black than to silica. The interfacial broadening is significantly slowed down with addition of merely phi (CB) = 0.01 (volume fraction) carbon black fillers. This volume level is much lower than that used in bulk rubbers (phi (CB) greater than or equal to 0.1). Pyrogeneous silica has a less pronounced effect on the interfacial characteristics. When both carbon and silica are incorporated into the PB layer, the effect of carbon black is offset by silica fillers. C1 SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. Exxon Res & Engn Co, Annandale, NJ 08801 USA. Exxon Chem Co, Polymer Sci Div, Baytown, TX 77520 USA. Exxon Chem Co, Butyl Technol Div, Baytown, TX 77520 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Rafailovich, MH (reprint author), SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. RI Koga, Tadanori/A-4007-2010; Ade, Harald/E-7471-2011; Urquhart, Stephen/A-6237-2014 OI Urquhart, Stephen/0000-0002-6415-6341 NR 32 TC 32 Z9 35 U1 1 U2 28 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 25 PY 2001 VL 34 IS 20 BP 7056 EP 7065 DI 10.1021/ma010183p PG 10 WC Polymer Science SC Polymer Science GA 475ZD UT WOS:000171199300029 ER PT J AU Wang, HC Thompson, DG Schoonover, JR Aubuchon, SR Palmer, RA AF Wang, HC Thompson, DG Schoonover, JR Aubuchon, SR Palmer, RA TI DMA-FTIR creep-recovery study of a poly(ester urethane) elastomer with molecular-level viscoelastic modeling SO MACROMOLECULES LA English DT Article ID INFRARED LINEAR DICHROISM; FOURIER-TRANSFORM IR; SPECTROSCOPY; POLYPROPYLENE; ORIENTATION; DEFORMATION; POLYMERS; STRAIN AB The combination of a research-grade DMA (dynamic mechanical analyzer) and an FTIR (Fourier transform infrared) spectrometer is demonstrated in simultaneous mechanical analysis and dynamic IR spectral measurement. In such a study, molecular-level responses to the deformation can be observed in the dynamic IR spectra and used to better understand the macroscopic viscoelastic behavior of the polymer sample characterized by monitoring the stress and strain. The measurements are performed on polymer films, with the DMA in the tensile geometry and IR measurement in the transmission mode. The DMA-FTIR technique is demonstrated in the creep-recovery study of an industrially important elastomer, Estane 5703. Differential orientation of various segments of the macromolecule during the creep and recovery process is observed. In a novel molecular-level application, Burger's model, a viscoelastic model that is often used to explain the bulk properties of materials, is applied to the analysis of the orientation of individual infrared dipoles. By replacing strain with orientation functions, contributions from separate molecular moieties to the macroscopic elasticity and viscosity are differentiated. Permanent damage observed after a large displacement is attributed to the irreversible alteration of the microscopic network structure of the elastomer and is discussed in light of IR spectral changes during the creep-recovery process. C1 Duke Univ, Dept Chem, Durham, NC 27708 USA. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. TA Instruments Inc, New Castle, DE 19720 USA. RP Palmer, RA (reprint author), Duke Univ, Dept Chem, Durham, NC 27708 USA. NR 25 TC 21 Z9 21 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 25 PY 2001 VL 34 IS 20 BP 7084 EP 7090 DI 10.1021/ma001783b PG 7 WC Polymer Science SC Polymer Science GA 475ZD UT WOS:000171199300033 ER PT J AU Chang, L Speck, O Miller, EN Braun, J Jovicich, J Koch, C Itti, L Ernst, T AF Chang, L Speck, O Miller, EN Braun, J Jovicich, J Koch, C Itti, L Ernst, T TI Neural correlates of attention and working memory deficits in HIV patients SO NEUROLOGY LA English DT Article ID FUNCTIONAL MAGNETIC-RESONANCE; COGNITIVE MOTOR COMPLEX; MULTICENTER AIDS COHORT; HUMAN PREFRONTAL CORTEX; BRAIN ACTIVATION; METABOLITE ABNORMALITIES; DEMENTIA COMPLEX; HOMOSEXUAL MEN; INDIVIDUALS; TASK AB Objectives: To evaluate the neural correlates of attention and working memory deficits in patients with HIV-1. Method: fMRI was used to evaluate brain activity in 11 patients with HIV and 11 age-, sex-, education-, and handedness-matched seronegative subjects, while performing a battery of tasks that required different levels of attention for working memory. Results: Patients with HIV showed greater brain activation (blood oxygenation level dependent signal changes) in some regions compared with control subjects while performing the same tasks. For the simpler tasks, patients with HIV showed greater activation in the parietal regions. However, with more difficult tasks, patients with HIV showed greater activation additionally in the frontal lobes. Reaction times during these tasks were slower but accuracy was similar in the patients with HIV compared with control subjects. Conclusion: Injury to the neural substrate caused by HIV infection may necessitate greater attentional modulation of the neural circuits, hence a greater use of the brain reserve; additional activation of the frontal lobes is required to perform the more complex tasks. The task-dependent increased frontal activation in patients with HIV suggests that the neural correlate of attentional deficits may be excessive attentional modulation as a result of frontostriatal brain injury. C1 Univ Calif Los Angeles, Harbor UCLA Med Ctr, Sch Med, Dept Neurol, Torrance, CA 90509 USA. Univ Calif Los Angeles, Harbor UCLA Med Ctr, Sch Med, Dept Psychiat, Torrance, CA 90509 USA. Univ Calif Los Angeles, Harbor UCLA Med Ctr, Sch Med, Dept Radiol, Torrance, CA 90509 USA. CALTECH, Computat & Neural Syst Program, Pasadena, CA 91125 USA. RP Chang, L (reprint author), Brookhaven Natl Lab, Dept Med, Bldg 490, Upton, NY 11973 USA. RI Jovicich, Jorge/D-2293-2010; Speck, Oliver/F-1406-2013; Braun, Jochen/F-1370-2013; OI Speck, Oliver/0000-0002-6019-5597; Braun, Jochen/0000-0002-8886-078X; Jovicich, Jorge/0000-0001-9504-7503; Koch, Christof/0000-0001-6482-8067 FU NCRR NIH HHS [MO1-RR00425]; NIDA NIH HHS [5 K20 DA00280]; PHS HHS [1R01 61427-01] NR 46 TC 103 Z9 109 U1 0 U2 9 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0028-3878 J9 NEUROLOGY JI Neurology PD SEP 25 PY 2001 VL 57 IS 6 BP 1001 EP 1007 PG 7 WC Clinical Neurology SC Neurosciences & Neurology GA 474PK UT WOS:000171115900013 PM 11571324 ER PT J AU Hollenbach, DF Herndon, JM AF Hollenbach, DF Herndon, JM TI Deep-Earth reactor: Nuclear fission, helium, and the geomagnetic field SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE Earth core; breeder reactor; natural reactor ID METEORITES; CORE AB Geomagnetic field reversals and changes in intensity are understandable from an energy standpoint as natural consequences of intermittent and/or variable nuclear fission chain reactions deep within the Earth. Moreover, deep-Earth production of helium, having He-3/He-4 ratios within the range observed from deep-mantle sources, is demonstrated to be a consequence of nuclear fission. Numerical simulations of a planetary-scale geo-reactor were made by using the SCALE sequence of codes. The results clearly demonstrate that such a geo-reactor (i) would function as a fast-neutron fuel breeder reactor; (ii) could, under appropriate conditions, operate over the entire period of geologic time; and (iii) would function in such a manner as to yield variable and/or intermittent output power. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Transdyne Corp, San Diego, CA 92131 USA. RP Hollenbach, DF (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 31 TC 47 Z9 50 U1 0 U2 5 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 25 PY 2001 VL 98 IS 20 BP 11085 EP 11090 DI 10.1073/pnas.201393998 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 476PC UT WOS:000171237100022 PM 11562483 ER PT J AU Laws, DD Bitter, HML Liu, K Ball, HL Kaneko, K Wille, H Cohen, FE Prusiner, SB Pines, A Wemmer, DE AF Laws, DD Bitter, HML Liu, K Ball, HL Kaneko, K Wille, H Cohen, FE Prusiner, SB Pines, A Wemmer, DE TI Solid-state NMR studies of the secondary structure of a mutant prion protein fragment of 55 residues that induces neurodegeneration SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID C-13 CHEMICAL-SHIFTS; CONFORMATIONAL CHARACTERIZATION; SYNTHETIC PEPTIDES; TRANSGENIC MICE; ALPHA-HELICES; SCRAPIE; TRANSITIONS; DISEASES AB The secondary structure of a 55-residue fragment of the mouse prion protein, MoPrP(89-143), was studied in randomly aggregated (dried from water) and fibrillar (precipitated from water/ acetonitrile) forms by C-13 solid-state NMR. Recent studies have shown that the fibrillar form of the P101L mutant of MoPrP(89-143) is capable of inducing prion disease in transgenic mice, whereas unaggregated or randomly aggregated samples do not provoke disease. Through analysis of C-13 chemical shifts, we have determined that both wild-type and mutant sequence MoPrP(89-143) form a mixture of beta -sheet and alpha -helical conformations in the randomly aggregated state although the beta -sheet content in MoPrP(89-143, P101L) is significantly higher than in the wild-type peptide. In a fibrillar state, MoPrP(89-143, P101L) is completely converted into beta -sheet, suggesting that the formation of a specific beta -sheet structure may be required for the peptide to induce disease. Studies of an analogous peptide from Syrian hamster PrP verify that sequence alterations in residues 101-117 affect the conformation of aggregated forms of the peptides. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif San Francisco, Dept Neurol, San Francisco, CA 94143 USA. Univ Calif San Francisco, Dept Biochem & Biophys, San Francisco, CA 94143 USA. RP Wemmer, DE (reprint author), Univ Calif Berkeley, Dept Chem, MC-1460, Berkeley, CA 94720 USA. RI Wille, Holger/C-2280-2008 OI Wille, Holger/0000-0001-5102-8706 FU NIA NIH HHS [AG-10770, P01 AG010770] NR 26 TC 58 Z9 64 U1 0 U2 6 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 25 PY 2001 VL 98 IS 20 BP 11686 EP 11690 DI 10.1073/pnas.201404298 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 476PC UT WOS:000171237100125 PM 11562491 ER PT J AU Tuch, DS Wedeen, VJ Dale, AM George, JS Belliveau, JW AF Tuch, DS Wedeen, VJ Dale, AM George, JS Belliveau, JW TI Conductivity tensor mapping of the human brain using diffusion tensor MRI SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID ELECTRICAL-CONDUCTIVITY; MAGNETIC-RESONANCE; FINITE-ELEMENT; TISSUE; MODEL; ANISOTROPY; FIELDS; FLUID; MEDIA; ROCKS AB Knowledge of the electrical conductivity properties of excitable tissues is essential for relating the electromagnetic fields generated by the tissue to the underlying electrophysiological currents. Efforts to characterize these endogenous currents from measurements of the associated electromagnetic fields would significantly benefit from the ability to measure the electrical conductivity properties of the tissue noninvasively. Here, using an effective medium approach, we show how the electrical conductivity tensor of tissue can be quantitatively inferred from the water selfdiffusion tensor as measured by diffusion tensor magnetic resonance imaging. The effective medium model indicates a strong linear relationship between the conductivity and diffusion tensor eigenvalues (respectively, sigma and d) in agreement with theoretical bounds and experimental measurements presented here (sigma /d approximate to 0.844 +/- 0.0545 S.s/mm(3), r(2) = 0.945). The extension to other biological transport phenomena is also discussed. C1 Massachusetts Gen Hosp, NMR Ctr, Charlestown, MA 02129 USA. MIT, Div Hlth Sci & Technol, Cambridge, MA 02139 USA. MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. Los Alamos Natl Lab, Biophys Grp, Los Alamos, NM 87545 USA. RP Tuch, DS (reprint author), Massachusetts Gen Hosp, NMR Ctr, 149 13th St, Charlestown, MA 02129 USA. RI Dale, Anders/A-5180-2010 FU NIMH NIH HHS [MH 60993-04] NR 37 TC 198 Z9 206 U1 3 U2 18 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 25 PY 2001 VL 98 IS 20 BP 11697 EP 11701 DI 10.1073/pnas.171473898 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 476PC UT WOS:000171237100127 PM 11573005 ER PT J AU Curry, JJ Adler, HG Shastri, SD Lawler, JE AF Curry, JJ Adler, HG Shastri, SD Lawler, JE TI Minority additive distributions in a ceramic metal-halide arc lamp using high-energy x-ray induced fluorescence SO APPLIED PHYSICS LETTERS LA English DT Article ID DISCHARGE; DENSITY AB X-ray induced fluorescence is used to measure the elemental densities of minority additives in a metal-halide arc contained inside a translucent ceramic envelope. A monochromatic x-ray beam from the Sector 1 Insertion Device beamline at the Advanced Photon Source is used to excite K-shell x-ray fluorescence in the constituents of a ceramic metal-halide arc lamp dosed with DyI3 and CsI. Fluorescence and scattered photons are collected by a cryogenic energy-resolving Ge detector. The high signal-to-noise spectra show strong fluorescence from Dy, Cs, and I, as well as elastic scattering from Hg. Radial distributions of the absolute elemental densities of Dy, Cs, and I are obtained. (C) 2001 American Institute of Physics. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. OSRAM Sylvania, Beverly, MA 01915 USA. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Curry, JJ (reprint author), Natl Inst Stand & Technol, Stop 8421, Gaithersburg, MD 20899 USA. NR 13 TC 17 Z9 17 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 24 PY 2001 VL 79 IS 13 BP 1974 EP 1976 DI 10.1063/1.1404401 PG 3 WC Physics, Applied SC Physics GA 472ZQ UT WOS:000171015200015 ER PT J AU Kent, PRC Zunger, A AF Kent, PRC Zunger, A TI Carrier localization and the origin of luminescence in cubic InGaN alloys SO APPLIED PHYSICS LETTERS LA English DT Article ID QUANTUM DOTS; SEMICONDUCTORS; IMMISCIBILITY; SINGLE; DIODES; GAINN AB The electronic structure and optical properties of cubic (nonpiezoelectric) InGaN are investigated using large scale atomistic empirical pseudopotential calculations. We find that (i) strong hole localization exists even in the homogeneous random alloy, with a preferential localization along the [1,1,0] In-N-In-N-In chains, (ii) even modest sized (< 50 Angstrom) indium rich quantum dots provide substantial quantum confinement and readily reduce emission energies relative to the random alloy by 200-300 meV, depending on size and composition, consistent with current photoluminescence, microscopy, and Raman data. The dual effects of alloy hole localization and localization of electrons and hole at intrinsic quantum dots are responsible for the emission characteristics of current grown cubic InGaN alloys. (C) 2001 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Kent, PRC (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Kent, Paul/A-6756-2008; Zunger, Alex/A-6733-2013 OI Kent, Paul/0000-0001-5539-4017; NR 21 TC 64 Z9 64 U1 3 U2 21 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 24 PY 2001 VL 79 IS 13 BP 1977 EP 1979 DI 10.1063/1.1405003 PG 3 WC Physics, Applied SC Physics GA 472ZQ UT WOS:000171015200016 ER PT J AU Kalyanaraman, R Haynes, TE Holland, OW Gossmann, HJL Rafferty, CS Gilmer, GH AF Kalyanaraman, R Haynes, TE Holland, OW Gossmann, HJL Rafferty, CS Gilmer, GH TI Binding energy of vacancies to clusters formed in Si by high-energy ion implantation SO APPLIED PHYSICS LETTERS LA English DT Article ID SILICON; DIFFUSION; DOPANTS; DEFECTS AB Measurements of the binding energy (E-b) of vacancies to vacancy clusters formed in silicon following high-energy ion implantation are reported. Vacancy clusters were created by 2 MeV, 2x10(15) cm(-2) dose Si implant and annealing. To prevent recombination of the excess vacancies (V-ex) with interstitials from the implant damage near the projected range (R-p), a Si-on-insulator substrate was used such that the R-p damage was separated from the V-ex by the buried oxide (BOX). Two V-ex regions were observed: one in the middle of the top Si layer (V-1(ex)) and the other at the front Si/BOX interface (V-2(ex)). The rates of vacancy evaporation were directly measured by Au labeling following thermal treatments at temperatures between 800 and 900 degreesC for times ranging from 600 to 1800 s. The rate of vacancy evaporation from V-2(ex) was observed to be greater than from V-1(ex). The binding energy of vacancies to clusters in the middle of the silicon top layer was 3.2 +/-0.2 eV as determined from the kinetics for vacancy evaporation. (C) 2001 American Institute of Physics. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Agere Syst, Murray Hill, NJ 07974 USA. RP Kalyanaraman, R (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 19 TC 19 Z9 19 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 24 PY 2001 VL 79 IS 13 BP 1983 EP 1985 DI 10.1063/1.1405814 PG 3 WC Physics, Applied SC Physics GA 472ZQ UT WOS:000171015200018 ER PT J AU Chen, J Lian, J Wang, LM Ewing, RC Boatner, LA AF Chen, J Lian, J Wang, LM Ewing, RC Boatner, LA TI X-ray photoelectron spectroscopy study of irradiation-induced amorphizaton of Gd2Ti2O7 SO APPLIED PHYSICS LETTERS LA English DT Article ID ION AB The radiation-induced evolution of the microstructure of Gd2Ti2O7, an important pyrochlore phase in radioactive waste disposal ceramics and a potential solid electrolyte and oxygen gas sensor, has been characterized using transmission electron microscopy and x-ray photoelectron spectroscopy. Following the irradiation of a Gd2Ti2O7 single crystal with 1.5 MeV Xe+ ions at a fluence of 1.7x10(14) Xe+/cm(2), cross-sectional transmission electron microscopy revealed a 300-nm-thick amorphous layer at the specimen surface. X-ray photoelectron spectroscopy analysis of the Ti 2p and O 1s electron binding energy shifts of Gd2Ti2O7 before and after amorphization showed that the main results of ion-irradiation-induced disorder are a decrease in the coordination number of titanium and a transformation of the Gd-O bond. These features resemble those occurring in titanate glass formation, and they have implications for the chemical stability and electronic properties of pyrochlores subjected to displacive radiation damage. (C) 2001 American Institute of Physics. C1 Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Chen, J (reprint author), Univ Michigan, Dept Nucl Engn & Radiol Sci, Ann Arbor, MI 48109 USA. RI Lian, Jie/A-7839-2010; Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 21 TC 37 Z9 38 U1 1 U2 11 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 24 PY 2001 VL 79 IS 13 BP 1989 EP 1991 DI 10.1063/1.1402647 PG 3 WC Physics, Applied SC Physics GA 472ZQ UT WOS:000171015200020 ER PT J AU Hubert, C Levy, J Rivkin, TV Carlson, C Parilla, PA Perkins, JD Ginley, DS AF Hubert, C Levy, J Rivkin, TV Carlson, C Parilla, PA Perkins, JD Ginley, DS TI Nanopolar reorientation in ferroelectric thin films SO APPLIED PHYSICS LETTERS LA English DT Article ID DIELECTRIC-CONSTANT AB The influence of varying oxygen pressure P(O-2) during the growth of Ba0.4Sr0.6TiO3 thin films is investigated using dielectric and local optical probes. A transition from in-plane to out-of-plane ferroelectricity is observed with increasing P(O-2). Signatures of in-plane and out-of-plane ferroelectricity are identified using dielectric response and time-resolved confocal scanning optical microscopy (TRCSOM). At the crossover pressure between in-plane and out-of-plane polarization (P-c=85 mTorr), TRCSOM measurements reveal a soft, highly dispersive out-of-plane polarization that reorients in plane under modest applied electric fields. At higher deposition pressures, the out-of-plane polarization is hardened and is less dispersive at microwave frequencies, and the dielectric tuning is suppressed. Nanopolar reorientation is believed to be responsible for the marked increase in dielectric tuning at P(O-2)=P-c. (C) 2001 American Institute of Physics. C1 Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Univ Pittsburgh, Dept Phys & Astron, 3941 OHara St, Pittsburgh, PA 15260 USA. EM jlevy@pitt.edu RI Levy, Jeremy/A-2081-2009 OI Levy, Jeremy/0000-0002-5700-2977 NR 19 TC 21 Z9 21 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 24 PY 2001 VL 79 IS 13 BP 2058 EP 2060 DI 10.1063/1.1406146 PG 3 WC Physics, Applied SC Physics GA 472ZQ UT WOS:000171015200043 ER PT J AU DelNegro, AS Woessner, SM Sullivan, BP Dattelbaum, DM Schoonover, JR AF DelNegro, AS Woessner, SM Sullivan, BP Dattelbaum, DM Schoonover, JR TI Stereospecific, unsymmetrical photosubstitution in a ligand-bridged dimer SO INORGANIC CHEMISTRY LA English DT Article ID COMPLEXES; RUTHENIUM(II); SUBSTITUTION AB Irradiation of the symmetrical dimer Re(CO)(3)(bpy)(mu (2)-dppene)Re(CO)(3)(bpy)(2+) in the presence of a coordinating group, L, results in only a single CO substitution due to internal quenching. The product unsymmetrical dimers are valuable precursors for linear oligomer preparation. [GRAPHICS] C1 Univ Wyoming, Dept Chem, Laramie, WY 82071 USA. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Sullivan, BP (reprint author), Univ Wyoming, Dept Chem, Laramie, WY 82071 USA. NR 14 TC 15 Z9 15 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 24 PY 2001 VL 40 IS 20 BP 5056 EP + DI 10.1021/ic001401i PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 475RG UT WOS:000171177500001 PM 11559054 ER PT J AU Huynh, MHV Jameson, DL Meyer, TJ AF Huynh, MHV Jameson, DL Meyer, TJ TI Preparation of heteroatom compounds by stepwise atom/group transfer in cis- and trans-[Os-VI(tPY)(Cl)(2)(N)](+) SO INORGANIC CHEMISTRY LA English DT Article ID NITROGEN ATOM-TRANSFER; PHOSPHORANIMINATO COMPLEXES; ARYLAZO SULFIDES; REACTIVITY; ION AB Rapid 2e(-) N- transfer reactions occur between both cis- and trans-[Os-VI(tpy)(Cl)(2)(N)](+) and Me2C6H3SH to give cis- and trans-[Os-IV(tpy)(Cl)(2)(NS(H)C6H3Me2)](+) with retention of stereo chemistry. These complexes undergo further reactions With PPh3 or p-MeOC6H4NH2 by net 2e(-), NSC6H3Me22- group transfer reactions to give the solvento complexes, cis- and trans- [Os-II(tpy)(Cl)(2)(NCCH3)], and the organic products, Ph3PNSC6H3Me2 and p-MeOC6H4N(H)NS(H)C6H3Me2, respectively. The sequential atom/group transfer reactions at the nitrido nitrogen atom provide a new stepwise synthetic route to PNS and NNS heteroatom compounds. [GRAPHICS] C1 Los Alamos Natl Lab, Div Chem, C SIC, Los Alamos, NM 87545 USA. Univ N Carolina, Venable & Kenan Labs, Dept Chem, Chapel Hill, NC 27599 USA. RP Huynh, MHV (reprint author), Los Alamos Natl Lab, Div Chem, C SIC, POB 1663, Los Alamos, NM 87545 USA. NR 14 TC 12 Z9 12 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 24 PY 2001 VL 40 IS 20 BP 5062 EP + DI 10.1021/ic010675i PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 475RG UT WOS:000171177500004 PM 11559057 ER PT J AU Huynh, MHV White, PS Meyer, TJ AF Huynh, MHV White, PS Meyer, TJ TI Redox chemistry of morpholine-based Os(VI)-hydrazido complexes: trans-[Os-VI(tPY)(Cl)(2)(NN(CH2)(4)O)](2+) SO INORGANIC CHEMISTRY LA English DT Article ID OSMIUM HYDRAZIDO COMPLEXES; CRYSTAL-STRUCTURE; OXIDATION AB The oxidations of benzyl alcohol, PPh3, and the sulfides (SEt2 and SPh2) (Ph = phenyl and Et = ethyl) by the Os(VI)-hydrazido complex trans-[Os-VI(tpy(Cl)(2)(NN(CH2)(4)O)](2+) (tpy = 2,2 ' :6 ' ,2 " -terpyridine and O(CH2)(4)N- = morpholide) have been investigated in CH3CN solution by UV-visible monitoring and product analysis by gas chromatography-mass spectrometry. For benzyl alcohol and the sulfides, the rate law for the formation of the Os(V)-hydrazido complex, trans- [Os-V(tpy)(Cl)(2)(NN(CH2)(4)O)](+), is first order in both trans-[Os-VI(typ(Cl)(2)(NN(CH2)(4)O)](2+) and reductant, with k(benzyl) (25.0 +/- 0.1 degreesC, CH3CN) = (1.80 +/- 0.07) x 10(-4) M-1 s(-1), k(SEt2) = (1.33 +/- 0.02) x 10(-1) M-1 s(-1), and k(SPh2) = (1.12 +/- 0.05) x 10(-1) M-1 s(-1). Reduction of trans-[Os-VI(tpy)(Cl)(2)(NN(CH2)(4)O)](2+) by PPh3 is rapid and accompanied by isomerization and solvolysis to give the Os(IV)hydrazido product, cis-[Os-IV(tpy)(NCCH3)(2)(NN(CH2)(4)O)](2+), and OPPh3. This reaction presumably occurs by net double Cl-atom transfer to PPh3 to give Cl2PPh3 that subsequently undergoes hydrolysis by trace H2O to give the Final product, OPPh3. In the X-ray crystal structure of the Os(IV)-hydrazido complex, the Os-N-N angle of 130.9(5)degrees and the Os-N bond length of 1.971(7) Angstrom are consistent with an Os-N double bond. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Univ N Carolina, Dept Chem, Venable & Kenan Labs, Chapel Hill, NC 27599 USA. RP Huynh, MHV (reprint author), Los Alamos Natl Lab, Div Chem, MS J514, Los Alamos, NM 87545 USA. NR 19 TC 7 Z9 7 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 24 PY 2001 VL 40 IS 20 BP 5231 EP 5235 DI 10.1021/ic001153q PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 475RG UT WOS:000171177500034 PM 11559087 ER PT J AU Faulkner, JS Ujfalussy, B Moghadam, N Stocks, GM Wang, Y AF Faulkner, JS Ujfalussy, B Moghadam, N Stocks, GM Wang, Y TI The mathematics of the polymorphous coherent potential approximation SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT Meeting on Electronic Structure and Alloy Phase Stability CY FEB, 2001 CL NEW ORLEANS, LA ID ELECTRONIC-STRUCTURE CALCULATIONS; INDIVIDUAL PAIR DISPLACEMENTS; CALCULATING PROPERTIES; DISORDERED ALLOYS; BAND-STRUCTURE; CU-NI; LATTICE; METALS; ORDER; MODEL AB The original coherent potential approximation (CPA) used for calculating the electronic states in substitutional solid-solution alloys contains the implicit assumption that the alloy is isomorphous. That is, all of the atoms of a given chemical type are assumed to be identical. The extension of the CPA philosophy to treat an alloy model in which all of the atoms are allowed to have distinct charges and potentials is called the polymorphous CPA (PCPA). This extension requires some interesting changes in the mathematical formalism that is used to develop the CPA equations. Aspects of the mathematical formalism of the PCPA will be discussed. In particular, the ergodic theorem from measure theory will be invoked to justify the new equations for the average Green's function. C1 Florida Atlantic Univ, Dept Phys, Alloy Res Ctr, Boca Raton, FL 33431 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37830 USA. Pittsburgh Supercomp Ctr, Pittsburgh, PA 15213 USA. RP Faulkner, JS (reprint author), Florida Atlantic Univ, Dept Phys, Alloy Res Ctr, Boca Raton, FL 33431 USA. RI Ujfalussy, Balazs/A-8155-2013; Stocks, George Malcollm/Q-1251-2016 OI Ujfalussy, Balazs/0000-0003-3338-4699; Stocks, George Malcollm/0000-0002-9013-260X NR 47 TC 5 Z9 5 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 EI 1361-648X J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD SEP 24 PY 2001 VL 13 IS 38 BP 8573 EP 8585 DI 10.1088/0953-8984/13/38/304 PG 13 WC Physics, Condensed Matter SC Physics GA 483JH UT WOS:000171631900005 ER PT J AU Dooley, DE Olson, DL Edwards, GR Gibbs, FE AF Dooley, DE Olson, DL Edwards, GR Gibbs, FE TI Development of an electronic phase diagram and the predictions of plutonium alloy phase stability using electronic properties SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT Meeting of the Eletronic Structure and Alloy Phase Stability CY FEB, 2001 CL NEW ORLEANS, LOUISIANA ID ACTINIDES AB Experimentally measuring electronic properties could have a significant impact in determining the kinetics of aged plutonium alloys. Phase stability of plutonium alloys can be assessed by using modified empirical electronic models in conjunction with measurements of electronic and magnetic properties of plutonium alloys. The issues surrounding the evaluation of aged plutonium alloys and the evolution of electronic-based alloy theories as applied to the prediction of the solubility of gallium in plutonium are presented. Using solid solution thermodynamics in combination with these electronic models, the phase diagram for dilute solid solutions can be estimated. There are numerous measurements that could be used to determine the relationship between a material's phase stability and its electronic structure. The measured properties of interest here are the Seebeck coefficient (thermopower), Hall coefficient and electrical resistivity. Combining three property measurements (or three other phase sensitive properties) into a three-dimensional plot with a specific property on each axis, a region of space will be formed that describes the stability of the phase. Also, the implications of assessing electronic data with this methodology are discussed. C1 Colorado Sch Mines, Golden, CO 80401 USA. RP Dooley, DE (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 37 TC 5 Z9 5 U1 0 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD SEP 24 PY 2001 VL 13 IS 38 BP 8677 EP 8696 DI 10.1088/0953-8984/13/38/310 PG 20 WC Physics, Condensed Matter SC Physics GA 483JH UT WOS:000171631900011 ER PT J AU Turchi, PEA Gonis, A AF Turchi, PEA Gonis, A TI Special issue containing papers from the procedings of the Hume-Rothery award symposium for professor B Gyorffy - Foreword SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Editorial Material C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Turchi, PEA (reprint author), Lawrence Livermore Natl Lab, POB 5508, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD SEP 24 PY 2001 VL 13 IS 38 BP U3 EP U3 PG 1 WC Physics, Condensed Matter SC Physics GA 483JH UT WOS:000171631900001 ER PT J AU Iancu, E Leonidov, A McLerran, L AF Iancu, E Leonidov, A McLerran, L TI Nonlinear gluon evolution in the color glass condensate: I SO NUCLEAR PHYSICS A LA English DT Article ID WILSON RENORMALIZATION-GROUP; QUASI-CLASSICAL APPROXIMATION; DEEP-INELASTIC SCATTERING; LOW X PHYSICS; BFKL POMERON; PARTON DENSITY; CHARGE-DENSITY; LARGE NUCLEUS; QCD; SATURATION AB We consider a nonlinear evolution equation recently proposed to describe the small-x hadronic physics in the regime of very high gluon density. This is a functional Fokker-Planck equation in terms of a classical random color source, which represents the color charge density of the partons with large x. In the saturation regime of interest, the coefficients of this equation must be known to all orders in the source strength. In this first paper of a series of two, we carefully derive the evolution equation, via a matching between classical and quantum correlations, and set up the framework for the exact background source calculation of its coefficients. We address and clarify many of the subtleties and ambiguities which have plagued past attempts at an explicit construction of this equation. We also introduce the physical interpretation of the saturation regime at small x as a Color Glass Condensate. In the second paper we shall evaluate the expressions derived here, and compare them to known results in various limits. (C) 2001 Elsevier Science B.V. All rights reserved. C1 CEA Saclay, Serv Phys Theor, F-91191 Gif Sur Yvette, France. PN Lebedev Phys Inst, Moscow 117924, Russia. Brookhaven Natl Lab, Dept Phys, Upton, NY 11979 USA. RP Iancu, E (reprint author), CEA Saclay, Serv Phys Theor, F-91191 Gif Sur Yvette, France. RI Leonidov, Andrey/M-4440-2013 NR 44 TC 752 Z9 753 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD SEP 24 PY 2001 VL 692 IS 3-4 BP 583 EP 645 DI 10.1016/S0375-9474(01)00642-X PG 63 WC Physics, Nuclear SC Physics GA 474BT UT WOS:000171085000008 ER PT J AU Farzan, Y Peres, OLG Smirnov, AY AF Farzan, Y Peres, OLG Smirnov, AY TI Neutrino mass spectrum and future beta decay experiments SO NUCLEAR PHYSICS B LA English DT Article DE neutrino masses and mixing; beta decay ID MAJORANA NEUTRINOS; OSCILLATIONS; DEGENERATE; NUCLEOSYNTHESIS; MECHANISM; SEARCH; LIMITS; BURST AB We study the discovery potential of future beta decay experiments on searches for the neutrino mass in the sub-eV range. and, in particular, KATRIN experiment with sensitivity m > 0.3 eV. Effects of neutrino mass and mixing on the beta decay spectrum in the neutrino schemes which explain the solar and atmospheric neutrino data are discussed. The schemes which lead to observable effects contain one or two sets of quasi-degenerate states. Future beta decay measurements will allow to check the three-neutrino scheme with mass degeneracy, moreover, the possibility appears to measure the CP-violating Majorana phase. Effects in the four-neutrino schemes which can also explain the LSND data are strongly restricted by the results of Bugey and CHOOZ oscillation experiments: apart from bending of the spectrum and the shift of the end point one expects appearance of small kink of (< 2%) size or suppressed tail after bending of the spectrum with rate below 2% of the expected rate for zero neutrino mass. We consider possible implications of future beta decay experiments for the neutrino mass spectrum, the determination of the absolute scale of neutrino mass and for establishing the nature of neutrinos. We show that beta decay measurements in combination with data from the oscillation and double beta decay experiments will allow to establish the structure of the scheme (hierarchical or non-hierarchical), the type of the hierarchy or ordering of states (normal or inverted) and to measure the relative CP-violating phase in the solar pair of states. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Scuola Int Super Studi Avanzati, I-34014 Trieste, Italy. Univ Estadual Campinas, UNICAMP, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP, Brazil. Abdus Salam Int Ctr Theoret Phys, I-34100 Trieste, Italy. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Scuola Int Super Studi Avanzati, Via Beirut 4, I-34014 Trieste, Italy. EM farzan@sissa.it; orlando@ifi.unicamp.br; smirnov@ictp.trieste.it RI Peres, Orlando/C-3760-2012; Inst. of Physics, Gleb Wataghin/A-9780-2017 OI Peres, Orlando/0000-0003-2104-8460; NR 84 TC 69 Z9 69 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD SEP 24 PY 2001 VL 612 IS 1-2 BP 59 EP 97 DI 10.1016/S0550-3213(01)00361-3 PG 39 WC Physics, Particles & Fields SC Physics GA 486XG UT WOS:000171841900003 ER PT J AU Affolder, T Akimoto, H Akopian, A Albrow, MG Amaral, P Amidei, D Anikeev, K Antos, J Apollinari, G Arisawa, T Artikov, A Asakawa, T Ashmanskas, W Azfar, F Azzi-Bacchetta, P Bacchetta, N Bachacou, H Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Baroiant, S Barone, M Bauer, G Bedeschi, F Belforte, S Bell, WH Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bhatti, A Binkley, M Bisello, D Bishai, M Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, SR Bocci, A Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A van den Brink, S Bromberg, C Brozovic, M Brubaker, E Bruner, N Buckley-Geer, E Budagov, J Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Cabrera, S Calafiura, P Campbell, M Carithers, W Carlson, J Carlsmith, D Caskey, W Castro, A Cauz, D Cerri, A Chan, AW Chang, PS Chang, PT Chapman, J Chen, C Chen, YC Cheng, MT Chertok, M Chiarelli, G Chirikov-Zorin, I Chlachidze, G Chlebana, F Christofek, L Chu, ML Chung, YS Ciobanu, CI Clark, AG Connolly, A Conway, J Cordelli, M Cranshaw, J Cropp, R Culbertson, R Dagenhart, D D'Auria, S DeJongh, F Dell'Agnello, S Dell'Orso, M Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Dominguez, A Donati, S Done, J D'Onofrio, M Dorigo, T Eddy, N Einsweiler, K Elias, JE Engels, E Erbacher, R Errede, D Errede, S Fan, Q Feild, RG Fernandez, JP Ferretti, C Field, RD Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Fukui, Y Furic, I Galeotti, S Gallas, A Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Gerdes, DW Giannetti, P Giromini, P Glagolev, V Glenzinski, D Gold, M Goldstein, J Gorelov, I Goshaw, AT Gotra, Y Goulianos, K Green, C Grim, G Gris, P Groer, L Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Haas, RM Haber, C Hahn, SR Hall, C Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hatakeyama, K Hauser, J Heinrich, J Heiss, A Herndon, M Hill, C Hoffman, KD Holck, C Hollebeek, R Holloway, L Hughes, R Huston, J Huth, J Ikeda, H Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kilminster, B Kim, BJ Kim, DH Kim, HS Kim, MJ Kim, SB Kim, SH Kim, YK Kirby, M Kirk, M Kirsch, L Klimenko, S Koehn, P Kondo, K Konigsberg, J Korn, A Korytov, A Kovacs, E Kroll, J Kruse, M Kuhlmann, SE Kurino, K Kuwabara, T Laasanen, AT Lai, N Lami, S Lammel, S Lancaster, J Lancaster, M Lander, R Lath, A Latino, G LeCompte, T Lee, AM Lee, K Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Litvintsev, DO Lobban, O Lockyer, N Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Mariotti, M Martignon, G Martin, A Matthews, JAJ Mayer, J Mazzanti, P McFarland, KS McIntyre, P McKigney, E Menguzzato, M Menzione, A Mesropian, C Meyer, A Miao, T Miller, R Miller, JS Minato, H Miscetti, S Mishina, M Mitselmakher, G Moggi, N Moore, E Moore, R Morita, Y Moulik, T Mulhearn, M Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Nachtman, J Nagaslaev, V Nahn, S Nakada, H Nakano, I Nelson, C Nelson, T Neu, C Neuberger, D Newman-Holmes, C Ngan, CYP Niu, H Nodulman, L Nomerotski, A Oh, SH Oh, YD Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Orejudos, W Pagliarone, C Palmonari, F Paoletti, R Papadimitriou, V Partos, D Patrick, J Pauletta, G Paulini, M Paus, C Pellett, D Pescara, L Phillips, TJ Piacentino, G Pitts, KT Pompos, A Pondrom, L Pope, G Popovic, M Prokoshin, F Proudfoot, J Ptohos, F Pukhov, O Punzi, G Rakitine, A Ratnikov, F Reher, D Reichold, A Ribon, A Riegler, W Rimondi, F Ristori, L Riveline, M Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Roy, A Ruiz, A Safonov, A St Denis, R Sakumoto, WK Saltzberg, D Sanchez, C Sansoni, A Santi, L Sato, H Savard, P Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Scodellaro, L Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semenov, A Semeria, F Shah, T Shapiro, MD Shepard, PF Shibayama, T Shimojima, M Shochet, M Sidoti, A Siegrist, J Sill, A Sinervo, P Singh, P Slaughter, AJ Sliwa, K Smith, C Snider, FD Solodsky, A Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, T Takano, T Takashima, R Takikawa, K Tamburello, P Tanaka, M Tannenbaum, B Tecchio, M Tesarek, R Teng, PK Terashi, K Tether, S Thompson, AS Thurman-Keup, R Tipton, P Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Tonelli, D Toyoda, H Trischuk, W de Troconiz, JF Tseng, J Turini, N Ukegawa, F Vaiciulis, T Valls, J Vejcik, S Velev, G Veramendi, G Vidal, R Vila, I Vilar, R Volobouev, I von der Mey, M Vucinic, D Wagner, RG Wagner, RL Wallace, NB Wan, Z Wang, C Wang, MJ Ward, B Waschke, S Watanabe, T Waters, D Watts, T Webb, R Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkes, T Williams, HH Wilson, P Winer, BL Winn, D Wolbers, S Wolinski, D Wolinski, J Wolinski, S Worm, S Wu, X Wyss, J Yao, W Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Yu, S Yu, Z Zanetti, A Zetti, F Zucchelli, S AF Affolder, T Akimoto, H Akopian, A Albrow, MG Amaral, P Amidei, D Anikeev, K Antos, J Apollinari, G Arisawa, T Artikov, A Asakawa, T Ashmanskas, W Azfar, F Azzi-Bacchetta, P Bacchetta, N Bachacou, H Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Baroiant, S Barone, M Bauer, G Bedeschi, F Belforte, S Bell, WH Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bhatti, A Binkley, M Bisello, D Bishai, M Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, SR Bocci, A Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A van den Brink, S Bromberg, C Brozovic, M Brubaker, E Bruner, N Buckley-Geer, E Budagov, J Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Cabrera, S Calafiura, P Campbell, M Carithers, W Carlson, J Carlsmith, D Caskey, W Castro, A Cauz, D Cerri, A Chan, AW Chang, PS Chang, PT Chapman, J Chen, C Chen, YC Cheng, MT Chertok, M Chiarelli, G Chirikov-Zorin, I Chlachidze, G Chlebana, F Christofek, L Chu, ML Chung, YS Ciobanu, CI Clark, AG Connolly, A Conway, J Cordelli, M Cranshaw, J Cropp, R Culbertson, R Dagenhart, D D'Auria, S DeJongh, F Dell'Agnello, S Dell'Orso, M Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Dominguez, A Donati, S Done, J D'Onofrio, M Dorigo, T Eddy, N Einsweiler, K Elias, JE Engels, E Erbacher, R Errede, D Errede, S Fan, Q Feild, RG Fernandez, JP Ferretti, C Field, RD Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Fukui, Y Furic, I Galeotti, S Gallas, A Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Gerdes, DW Giannetti, P Giromini, P Glagolev, V Glenzinski, D Gold, M Goldstein, J Gorelov, I Goshaw, AT Gotra, Y Goulianos, K Green, C Grim, G Gris, P Groer, L Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Haas, RM Haber, C Hahn, SR Hall, C Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hatakeyama, K Hauser, J Heinrich, J Heiss, A Herndon, M Hill, C Hoffman, KD Holck, C Hollebeek, R Holloway, L Hughes, R Huston, J Huth, J Ikeda, H Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kilminster, B Kim, BJ Kim, DH Kim, HS Kim, MJ Kim, SB Kim, SH Kim, YK Kirby, M Kirk, M Kirsch, L Klimenko, S Koehn, P Kondo, K Konigsberg, J Korn, A Korytov, A Kovacs, E Kroll, J Kruse, M Kuhlmann, SE Kurino, K Kuwabara, T Laasanen, AT Lai, N Lami, S Lammel, S Lancaster, J Lancaster, M Lander, R Lath, A Latino, G LeCompte, T Lee, AM Lee, K Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Litvintsev, DO Lobban, O Lockyer, N Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Mariotti, M Martignon, G Martin, A Matthews, JAJ Mayer, J Mazzanti, P McFarland, KS McIntyre, P McKigney, E Menguzzato, M Menzione, A Mesropian, C Meyer, A Miao, T Miller, R Miller, JS Minato, H Miscetti, S Mishina, M Mitselmakher, G Moggi, N Moore, E Moore, R Morita, Y Moulik, T Mulhearn, M Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Nachtman, J Nagaslaev, V Nahn, S Nakada, H Nakano, I Nelson, C Nelson, T Neu, C Neuberger, D Newman-Holmes, C Ngan, CYP Niu, H Nodulman, L Nomerotski, A Oh, SH Oh, YD Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Orejudos, W Pagliarone, C Palmonari, F Paoletti, R Papadimitriou, V Partos, D Patrick, J Pauletta, G Paulini, M Paus, C Pellett, D Pescara, L Phillips, TJ Piacentino, G Pitts, KT Pompos, A Pondrom, L Pope, G Popovic, M Prokoshin, F Proudfoot, J Ptohos, F Pukhov, O Punzi, G Rakitine, A Ratnikov, F Reher, D Reichold, A Ribon, A Riegler, W Rimondi, F Ristori, L Riveline, M Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Roy, A Ruiz, A Safonov, A St Denis, R Sakumoto, WK Saltzberg, D Sanchez, C Sansoni, A Santi, L Sato, H Savard, P Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Scodellaro, L Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semenov, A Semeria, F Shah, T Shapiro, MD Shepard, PF Shibayama, T Shimojima, M Shochet, M Sidoti, A Siegrist, J Sill, A Sinervo, P Singh, P Slaughter, AJ Sliwa, K Smith, C Snider, FD Solodsky, A Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, T Takano, T Takashima, R Takikawa, K Tamburello, P Tanaka, M Tannenbaum, B Tecchio, M Tesarek, R Teng, PK Terashi, K Tether, S Thompson, AS Thurman-Keup, R Tipton, P Tkaczyk, S Toback, D Tollefson, K Tollestrup, A Tonelli, D Toyoda, H Trischuk, W de Troconiz, JF Tseng, J Turini, N Ukegawa, F Vaiciulis, T Valls, J Vejcik, S Velev, G Veramendi, G Vidal, R Vila, I Vilar, R Volobouev, I von der Mey, M Vucinic, D Wagner, RG Wagner, RL Wallace, NB Wan, Z Wang, C Wang, MJ Ward, B Waschke, S Watanabe, T Waters, D Watts, T Webb, R Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkes, T Williams, HH Wilson, P Winer, BL Winn, D Wolbers, S Wolinski, D Wolinski, J Wolinski, S Worm, S Wu, X Wyss, J Yao, W Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Yu, S Yu, Z Zanetti, A Zetti, F Zucchelli, S CA CDF Collaboration TI Measurement of d sigma/dM and forward-backward charge asymmetry for high-mass Drell-Yan e(+)e(-) pairs from p(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID QED RADIATIVE-CORRECTIONS; UNIVERSAL MONTE-CARLO; (P)OVER-BAR-P COLLISIONS; PARTON DISTRIBUTIONS; HADRON COLLISIONS; CROSS-SECTION; K-FACTOR; DILEPTONS; ENERGIES; PHOTOS AB We report on a measurement of the mass dependence of the forward-backward charge asymmetry, A(FB), and production cross section d sigma /dM for e(+)e(-) pairs with mass M-ee > 40 GeV/c(2). The data sample consists of 108 pb(-1) of p (p) over bar collisions at roots = 1.8 TeV taken by the Collider Detector at Fermilab during 1992-1995. The measured asymmetry and d sigma /dM are compared with the predictions of the standard model and a model with an extra Z' gauge boson. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40127 Bologna, Italy. Brandeis Univ, Waltham, MA 02254 USA. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Cantabria, CSIC, Inst Fis Cantabria, E-39005 Santander, Spain. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Joint Inst Nucl Res, RU-141980 Dubna, Russia. Duke Univ, Durham, NC 27708 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Florida, Gainesville, FL 32611 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Geneva, CH-1211 Geneva 4, Switzerland. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Harvard Univ, Cambridge, MA 02138 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Univ Illinois, Urbana, IL 61801 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. Kyungpook Natl Univ, Ctr High Energy Phys, Taegu 702701, South Korea. Seoul Natl Univ, Seoul 151742, South Korea. Sungkyunkwan Univ, Suwon 440746, South Korea. High Energy Accelerator Res Org, Tsukuba, Ibaraki 305, Japan. MIT, Cambridge, MA 02139 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Ohio State Univ, Columbus, OH 43210 USA. Osaka City Univ, Osaka 588, Japan. Univ Oxford, Oxford OX1 3RH, England. Univ Padua, Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Ist Nazl Fis Nucl, I-56100 Pisa, Italy. Scuola Normale Super Pisa, I-56100 Pisa, Italy. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Rockefeller Univ, New York, NY 10021 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Texas A&M Univ, College Stn, TX 77843 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Univ Toronto, Inst Particle Phys, Toronto, ON M5S 1A7, Canada. Univ Trieste Udine, Ist Nazl Fis Nucl, Udine, Italy. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Tufts Univ, Medford, MA 02155 USA. Waseda Univ, Tokyo 169, Japan. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06520 USA. RP Affolder, T (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Introzzi, Gianluca/K-2497-2015; Gorelov, Igor/J-9010-2015; Chiarelli, Giorgio/E-8953-2012; Kim, Soo-Bong/B-7061-2014; Gallas Torreira, Abraham Antonio/K-6508-2014; Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Nomerotski, Andrei/A-5169-2010; Ruiz, Alberto/E-4473-2011; Scodellaro, Luca/K-9091-2014; St.Denis, Richard/C-8997-2012; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Cabrera Urban, Susana/H-1376-2015; Prokoshin, Fedor/E-2795-2012 OI Introzzi, Gianluca/0000-0002-1314-2580; Gorelov, Igor/0000-0001-5570-0133; Lami, Stefano/0000-0001-9492-0147; Latino, Giuseppe/0000-0002-4098-3502; Wyss, Jeffery/0000-0002-8277-4012; Lancaster, Mark/0000-0002-8872-7292; Toback, David/0000-0003-3457-4144; Gallinaro, Michele/0000-0003-1261-2277; Paulini, Manfred/0000-0002-6714-5787; Turini, Nicola/0000-0002-9395-5230; CHANG, PAO-TI/0000-0003-4064-388X; Chiarelli, Giorgio/0000-0001-9851-4816; Gallas Torreira, Abraham Antonio/0000-0002-2745-7954; Ruiz, Alberto/0000-0002-3639-0368; Scodellaro, Luca/0000-0002-4974-8330; Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Prokoshin, Fedor/0000-0001-6389-5399 NR 28 TC 2 Z9 2 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 24 PY 2001 VL 87 IS 13 AR 131802 DI 10.1103/PhysRevLett.87.131802 PG 6 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500006 ER PT J AU Ahn, JK Ajimura, S Akikawa, H Bassalleck, B Berdoz, A Carman, D Chrien, RE Davis, CA Eugenio, P Fischer, H Franklin, GB Franz, J Fukuda, T Gan, L Hotchi, H Ichikawa, A Imai, K Kahana, SH Khaustov, P Kishimoto, T Koran, P Kohri, H Kourepin, A Kubota, K Landry, M May, M Meyer, C Meziani, Z Minami, S Miyachi, T Nagae, T Nakano, J Outa, H Paschke, K Pile, P Prokhabatilov, M Quinn, BP Rasin, V Rusek, A Schmitt, H Schumacher, RA Sekimoto, M Shileev, K Shimizu, Y Sutter, R Tamagawa, T Tang, L Tanida, K Yamamoto, K Yuan, L AF Ahn, JK Ajimura, S Akikawa, H Bassalleck, B Berdoz, A Carman, D Chrien, RE Davis, CA Eugenio, P Fischer, H Franklin, GB Franz, J Fukuda, T Gan, L Hotchi, H Ichikawa, A Imai, K Kahana, SH Khaustov, P Kishimoto, T Koran, P Kohri, H Kourepin, A Kubota, K Landry, M May, M Meyer, C Meziani, Z Minami, S Miyachi, T Nagae, T Nakano, J Outa, H Paschke, K Pile, P Prokhabatilov, M Quinn, BP Rasin, V Rusek, A Schmitt, H Schumacher, RA Sekimoto, M Shileev, K Shimizu, Y Sutter, R Tamagawa, T Tang, L Tanida, K Yamamoto, K Yuan, L TI Production of H-4(Lambda Lambda) hypernuclei SO PHYSICAL REVIEW LETTERS LA English DT Article ID DECAYS AB An experiment demonstrating the production of double- Lambda hypernuclei in (K-, K+) reactions on Be-9 was carried out at the D6 line in the BNL alternating-gradient synchrotron. The technique was the observation of pions produced in sequential mesonic weak decay, each pion associated with one unit of strangeness change. The results indicate the production of a significant number of the double hypernucleus H-4(Lambda Lambda) and the twin hypernuclei H-4(Lambda) and H-3(Lambda). The relevant decay chains are discussed and a simple model of the production mechanism is presented. An implication of this experiment is that the existence of an S = -2 dibaryon more than a few MeV below the Lambda Lambda mass is unlikely. C1 Pusan Natl Univ, Dept Phys, Pusan 609735, South Korea. Brookhaven Natl Lab, Upton, NY 11973 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Univ Freiburg, Dept Phys, D-79104 Freiburg, Germany. Hampton Univ, Dept Phys, Hampton, VA 23668 USA. High Energy Accelerator Res Org, Tsukuba, Ibaraki 3050801, Japan. Russian Acad Sci, Inst Nucl Res, Moscow 117312, Russia. Kyoto Univ, Dept Phys, Sakyo Ku, Kyoto 6068502, Japan. Univ Manitoba, Dept Phys & Astron, Winnipeg, MB R3T 2N2, Canada. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. Osaka Univ, Dept Phys, Osaka 5600043, Japan. Temple Univ, Dept Phys, Philadelphia, PA 19122 USA. Univ Tokyo, Dept Phys, Tokyo 1130033, Japan. TRIUMF, Vancouver, BC V6T 2A3, Canada. Osaka Electrocommun Univ, Phys Lab, Osaka 5728530, Japan. RP Ahn, JK (reprint author), Pusan Natl Univ, Dept Phys, Pusan 609735, South Korea. RI Ahn, Jung Keun/C-1293-2008; Schumacher, Reinhard/K-6455-2013 OI Schumacher, Reinhard/0000-0002-3860-1827 NR 19 TC 91 Z9 97 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 24 PY 2001 VL 87 IS 13 AR 132504 DI 10.1103/PhysRevLett.87.132504 PG 5 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500011 PM 11580581 ER PT J AU Alavi-Harati, A Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barbosa, RF Barker, AR Barrio, M Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, G Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Glazov, A Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hamm, J Hanagaki, K Hidaka, S Hsiung, YB Jejer, V Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL Mikelsons, P Monnier, E Nakaya, T Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Qi, XR Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Shields, J Slater, W Solomey, N Somalwar, SV Stone, RL Swallow, EC Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Turner, SE Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Yamanaka, T Zimmerman, ED AF Alavi-Harati, A Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barbosa, RF Barker, AR Barrio, M Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, G Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Glazov, A Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hamm, J Hanagaki, K Hidaka, S Hsiung, YB Jejer, V Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL Mikelsons, P Monnier, E Nakaya, T Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Qi, XR Quinn, B Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Shields, J Slater, W Solomey, N Somalwar, SV Stone, RL Swallow, EC Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Turner, SE Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Yamanaka, T Zimmerman, ED CA KTeV Collaboration TI First measurement of form factors of the decay Xi(0)->Sigma(+) e(-)(nu)over-bar(e) SO PHYSICAL REVIEW LETTERS LA English DT Article ID BREAKING AB We present the first measurement of the form factor ratios g(1)/f(1) (direct axial vector to vector), g(2)/f(1) (second class current), and f(2)/f(1) (weak magnetism) for the decay Xi (o) --> Sigma (+)e(-)<()over bar>(e) using the KTeV (E799) beam line and detector at Fermilab. From the Sigma (+) polarization measured with the decay Sigma (+) --> p pi (o) and the e(-) - <()over bar> correlation, we measure g(1)/f(1) to be 1.32 (+0.21)(-0.17) (stat) +/- 0.05(syst), assuming the SU(3)(f) (flavor) values for g(2)/f(1) and f(2)/f(1). Our results are all consistent with exact SU(3)(f) symmetry. C1 Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Arizona, Tucson, AZ 85721 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Colorado, Boulder, CO 80309 USA. Elmhurst Coll, Elmhurst, IL 60126 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Osaka Univ, Osaka 5600043, Japan. Rice Univ, Houston, TX 77005 USA. Rutgers State Univ, Piscataway, NJ 08854 USA. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. Univ Virginia, Inst Nucl & Particle Phys, Charlottesville, VA 22901 USA. Univ Wisconsin, Madison, WI 53706 USA. Univ Sao Paulo, Sao Paulo, Brazil. CNRS, CPP Marseille, F-75700 Paris, France. RP Winston, R (reprint author), Univ Chicago, Enrico Fermi Inst, 5640 S Ellis Ave, Chicago, IL 60637 USA. EM r-winston@uchicago.edu NR 10 TC 30 Z9 30 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 24 PY 2001 VL 87 IS 13 AR 132001 DI 10.1103/PhysRevLett.87.132001 PG 4 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500007 PM 11580577 ER PT J AU Cooper, JR Krucken, R Beausang, CW Novak, JR Dewald, A Klug, T Kemper, G von Brentano, P Carpenter, MP Janssens, RVF Lister, CJ Wiedenhover, I AF Cooper, JR Krucken, R Beausang, CW Novak, JR Dewald, A Klug, T Kemper, G von Brentano, P Carpenter, MP Janssens, RVF Lister, CJ Wiedenhover, I TI Crossing of shears bands in Pb-197: B(M1) values and semiclassical description SO PHYSICAL REVIEW LETTERS LA English DT Article ID DECAY CURVE METHOD; LIFETIME MEASUREMENTS; MECHANISM; NUCLEI; ROTATION; STATES AB Subpicosccond lifetimes of states in shears band 1 in Pb-197 were measured by means of the recoil distance method employing Gammasphere and the New Yale Plunger Device. The extracted reduced matrix elements, B(M1), show a clear sensitivity to the crossing of different shears configurations reflecting the closing and reopening of the shears blades. The energies and B(Ml) values in the band crossing region are successfully described in the framework of the semiclassical model of the shears bands. The relevance of core rotation contributions are shown. The results point to the existence of shears states with an angular momentum coupling angle larger than 90 degrees. C1 Yale Univ, AW Wright Nucl Struct Lab, New Haven, CT 06520 USA. Univ Cologne, Inst Kernphys, D-5000 Cologne, Germany. Argonne Natl Lab, Argonne, IL 60439 USA. RP Yale Univ, AW Wright Nucl Struct Lab, New Haven, CT 06520 USA. RI Carpenter, Michael/E-4287-2015; Dewald, Alfred/O-5810-2015; Kruecken, Reiner/A-1640-2013 OI Carpenter, Michael/0000-0002-3237-5734; Kruecken, Reiner/0000-0002-2755-8042 NR 27 TC 19 Z9 19 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 24 PY 2001 VL 87 IS 13 AR 132503 DI 10.1103/PhysRevLett.87.132503 PG 4 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500010 PM 11580580 ER PT J AU Fischer, SM Lister, CJ Balamuth, DP Bauer, R Becker, JA Bernstein, LA Carpenter, MP Durell, J Fotiades, N Freeman, SJ Garrett, PE Hausladen, PA Janssens, RVF Jenkins, D Leddy, M Ressler, J Schwartz, J Svelnys, D Sarantites, DG Seweryniak, D Varley, BJ Wyss, R AF Fischer, SM Lister, CJ Balamuth, DP Bauer, R Becker, JA Bernstein, LA Carpenter, MP Durell, J Fotiades, N Freeman, SJ Garrett, PE Hausladen, PA Janssens, RVF Jenkins, D Leddy, M Ressler, J Schwartz, J Svelnys, D Sarantites, DG Seweryniak, D Varley, BJ Wyss, R TI Alignment delays in the N = Z nuclei Kr-72, Sr-76, and Zr-80 SO PHYSICAL REVIEW LETTERS LA English DT Article ID ROTATIONAL BANDS; N=Z; ZIRCONIUM; MODEL; T=0 AB The ground state rotational bands of the N = Z nuclei Kr-72, Sr-76, and Zr-80 have been extended into the angular momentum region where rotation alignment of particles is normally expected. By measuring the moments of inertia of these bands we have observed a consistent increase in the rotational frequency required to start pair breaking, when compared to neighboring nuclei. Kr-72 shows the most marked effect. It has been widely suggested that these "delayed alignments" arise from np-pairing correlations. However, alignment frequencies are very sensitive to shape degrees of freedom and normal pairing, so the new experimental observations are still open to interpretation. C1 De Paul Univ, Dept Phys, Chicago, IL 60614 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Penn, Dept Phys & Astron, Philadelphia, PA 19104 USA. Lawrence Livermore Natl Lab, Div Phys, Livermore, CA 94550 USA. Univ Manchester, Dept Phys, Manchester M13 9PL, Lancs, England. Rutgers State Univ, Dept Phys & Astron, New Brunswick, NJ 08903 USA. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Royal Inst Technol, KTH Frescati, S-10405 Stockholm, Sweden. RP Fischer, SM (reprint author), De Paul Univ, Dept Phys, Chicago, IL 60614 USA. RI Ressler, Jennifer Jo/F-2279-2010; Freeman, Sean/B-1280-2010; Carpenter, Michael/E-4287-2015 OI Freeman, Sean/0000-0001-9773-4921; Carpenter, Michael/0000-0002-3237-5734 NR 31 TC 57 Z9 60 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 24 PY 2001 VL 87 IS 13 AR 132501 DI 10.1103/PhysRevLett.87.132501 PG 4 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500008 PM 11580578 ER PT J AU Garrett, PE Ormand, WE Appelbe, D Bauer, RW Becker, JA Bernstein, LA Cameron, JA Carpenter, MP Janssens, RVF Lister, CJ Seweryniak, D Tavukcu, E Warner, DD AF Garrett, PE Ormand, WE Appelbe, D Bauer, RW Becker, JA Bernstein, LA Cameron, JA Carpenter, MP Janssens, RVF Lister, CJ Seweryniak, D Tavukcu, E Warner, DD TI Observation of Cr-46 and testing the isobaric multiplet mass equation at high spin SO PHYSICAL REVIEW LETTERS LA English DT Article ID BAND TERMINATION; NUCLEI; SHELL AB The ground state band in Cr-46 and the isospin T = 1 band in V-46 have been delineated up to I-pi = 10(+) (tentatively 12(+)). These observations complete the highest spin T = 1 isospin triplet known. Following the isobaric multiplet mass equation, a combination of level energies in Cr-46, Ti-46, and V-46 are taken to highlight the angular momentum dependence of the isovector and isotensor parts of the interaction. The results are compared with full-fp-space shell model calculations. The influence of the one-body and two-body contributions to the isovector energy difference are investigated. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. N Carolina State Univ, Raleigh, NC 27695 USA. SERC, Daresbury Lab, CLRC, Warrington WA4 4AD, Cheshire, England. RP Garrett, PE (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 21 TC 39 Z9 39 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 24 PY 2001 VL 87 IS 13 AR 132502 DI 10.1103/PhysRevLett.87.132502 PG 4 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500009 PM 11580579 ER PT J AU Hughes, DA Hansen, N AF Hughes, DA Hansen, N TI Graded nanostructures produced by sliding and exhibiting universal behavior SO PHYSICAL REVIEW LETTERS LA English DT Article ID DEFORMATION; FRICTION; STRESS; METALS AB Nanostructured copper was produced by deformation under large sliding loads. In the near surface layers, 10 nm scale microstructures form and coarsen with increasing depth from the surface. The graded structure enables characterization of the structural scale over several orders of magnitude. Analysis reveals that universal scaling of the microstructure exists from 10000 to 10 nm. The limit of scale is pushed to an order of magnitude of the ultimate scale at which the crystallinity is lost. This universality opens the door for easy manufacture of ever finer scale components by deformation. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Riso Natl Lab, Dept Mat, DK-4000 Roskilde, Denmark. RP Sandia Natl Labs, MS 9405,POB 969, Livermore, CA 94551 USA. EM darcyhu@sandia.gov NR 15 TC 109 Z9 114 U1 5 U2 46 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 24 PY 2001 VL 87 IS 13 AR 135503 DI 10.1103/PhysRevLett.87.135503 PG 4 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500034 PM 11580604 ER PT J AU Lamoreaux, SK AF Lamoreaux, SK TI Comment on "Thermal effects on the Casimir force in the 0.1-5 mu m range" SO PHYSICAL REVIEW LETTERS LA English DT Editorial Material C1 Los Alamos Natl Lab, Phys Div P23, Los Alamos, NM 87545 USA. RP Lamoreaux, SK (reprint author), Los Alamos Natl Lab, Phys Div P23, M-S H803, Los Alamos, NM 87545 USA. NR 5 TC 19 Z9 19 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 24 PY 2001 VL 87 IS 13 AR 139101 DI 10.1103/PhysRevLett.87.139101 PG 1 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500060 ER PT J AU Miranovic, P Kogan, VG AF Miranovic, P Kogan, VG TI Elastic moduli of vortex lattices within nonlocal London model SO PHYSICAL REVIEW LETTERS LA English DT Article ID FLUX-LINE-LATTICE; STRUCTURAL PHASE-TRANSITION; NEUTRON-SCATTERING; SUPERCONDUCTORS; ERNI2B2C; YNI2B2C; FIELD AB Vortex lattice (VL) elastic response is analyzed within the nonlocal London model which hold for high-kappa clean superconductors. The squash modulus vanishes at the field H-square where VL undergoes a square-to-rhombus transition. For H > H-square, where the square VL is stable, the rotation modulus turns zero at H = H-r, indicating VL instability to rotations. The shear modulus depends on the shear direction; the dependence is strong in the vicinity of H-square where the square VL is soft with respect to the shear along [110]. The H dependences of the moduli are evaluated for LuNi2B2C. C1 Univ Montenegro, Dept Phys, Podgorica, Yugoslavia. Ames Lab, Ames, IA 50011 USA. Dept Phys, Ames, IA 50011 USA. RP Miranovic, P (reprint author), Univ Montenegro, Dept Phys, POB 211, Podgorica, Yugoslavia. NR 19 TC 12 Z9 12 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 24 PY 2001 VL 87 IS 13 AR 137002 DI 10.1103/PhysRevLett.87.137002 PG 4 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500047 PM 11580617 ER PT J AU Schachter, L Colby, E Siemann, RH AF Schachter, L Colby, E Siemann, RH TI Saturation of bunch-wave interaction in an active medium SO PHYSICAL REVIEW LETTERS LA English DT Article ID PARTICLE-ACCELERATION; ELECTRON-ACCELERATOR; LASER ACCELERATION; RESONANT MEDIUM; CERENKOV; VACUUM; CHERENKOV; GRADIENT; PLASMAS; FORCES AB We determine the set of equations which describe the dynamics of electrons in the presence of a wave propagating in an active medium. Simulation results indicate that, even when virtually all the energy is drained from the medium, electrons remain trapped by the accelerating wave. In spite of saturation, gradients of a few GV/m may become available. C1 Technion Israel Inst Technol, Dept Elect Engn, IL-32000 Haifa, Israel. Stanford Univ, SLAC, Menlo Pk, CA 94025 USA. RP Technion Israel Inst Technol, Dept Elect Engn, IL-32000 Haifa, Israel. NR 22 TC 7 Z9 7 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 24 PY 2001 VL 87 IS 13 AR 134802 DI 10.1103/PhysRevLett.87.134802 PG 4 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500025 PM 11580595 ER PT J AU Sernelius, BE AF Sernelius, BE TI Comment on "Thermal effects on the Casimir force in the 0.1-5 mu m range" - Reply SO PHYSICAL REVIEW LETTERS LA English DT Editorial Material C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Sernelius, BE (reprint author), Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RI Sernelius, Bo/I-4566-2012 OI Sernelius, Bo/0000-0002-6281-868X NR 5 TC 22 Z9 22 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 24 PY 2001 VL 87 IS 13 AR 139102 DI 10.1103/PhysRevLett.87.139102 PG 1 WC Physics, Multidisciplinary SC Physics GA 476HE UT WOS:000171219500061 ER PT J AU Yu, HG Gonzalez-Lezana, T Marr, AJ Muckerman, JT Sears, TJ AF Yu, HG Gonzalez-Lezana, T Marr, AJ Muckerman, JT Sears, TJ TI Experimental and theoretical studies of the near-infrared spectrum of bromomethylene SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FREQUENCY-MODULATION SPECTROSCOPY; SUBSTITUTED CARBENES; HCBR; DCBR; GAP; CL; BR AB New measurements in the (A) over tilde (1)A " - (X) over tilde (1)A' band system of monobromomethylene (HCBr) at near-infrared wavelengths are reported. Rotationally resolved spectra of HCBr and DCBr for both naturally occurring Br isotopes are analyzed and provide accurate energies for the low-lying bending vibrational levels in both the (A) over tilde and (X) over tilde states. The experimental results are compared to extensive ab initio calculations of these two states and the low-lying (a) over tilde (3)A " state. The ab initio T-00 value for the (A) over tilde-(X) over tilde system is calculated within 500 cm(-1) of the experimental results. For the triplet state, T-00 (<()over tilde>-(X) over tilde) was calculated to be 1833 cm(-1). The measurements of the bending intervals in the (X) over tilde (1)A' state suggest that this is about 250 cm(-1) too low. With this shift and inclusion of spin-orbit coupling between the (a) over tilde and (X) over tilde states, the calculated bending vibrational levels in the (X) over tilde state reproduce the observations, and the calculations make testable predictions of the position of the triplet and other singlet state vibronic levels. Combining the experimental and computational results, we estimate the triplet, T-00(<()over tilde>-(X) over tilde), excitation energy to be 2028 cm(-1). (C) 2001 American Institute of Physics. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Yu, HG (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Muckerman, James/D-8752-2013; Sears, Trevor/B-5990-2013; Yu, Hua-Gen/N-7339-2015 OI Sears, Trevor/0000-0002-5559-0154; NR 31 TC 36 Z9 36 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 22 PY 2001 VL 115 IS 12 BP 5433 EP 5444 DI 10.1063/1.1386812 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 472YZ UT WOS:000171013700013 ER PT J AU Mendez, S Curro, JG Putz, M Bedrov, D Smith, GD AF Mendez, S Curro, JG Putz, M Bedrov, D Smith, GD TI Explicit inclusion of the solvent molecules SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INTEGRAL-EQUATION THEORY; THERMODYNAMIC PERTURBATION-THEORY; POLYMER-CHAIN; DYNAMICS SIMULATION; EQUILIBRIUM-THEORY; EXCESS ELECTRONS; SIMPLE FLUIDS; LIQUIDS; CONFORMATION; DIMENSIONS AB Self-consistent Polymer Reference Interaction Site Model (PRISM) calculations and molecular dynamics (MD) simulations were performed on athermal solutions of linear polymers. Unlike most previous treatments of polymer solutions, we explicitly included the solvent molecules. The polymers were modeled as tangent site chains and the solvent molecules were taken to be spherical sites having the same intermolecular potential as the polymer sites. The PRISM theory was solved self-consistently for both the single chain structure and intermolecular correlations as a function of chain length and concentration. The rms end-to-end distance from PRISM theory was found to be in agreement with corresponding MD simulations, and exhibited molecular weight dependence in accordance with scaling predictions in the dilute and concentrated solution limits. The presence of explicit solvent molecules had a significant effect on the packing of the polymer by inducing additional structure in the intermolecular radial distribution function between polymer sites. Using the direct correlation functions from the athermal solution and the random phase approximation, we were able to estimate the spinodal curves for solutions when polymer and solvent attractions were turned on. We found significant deviations from Flory-Huggins theory that are likely due to compressibility and nonrandom mixing effects. (C) 2001 American Institute of Physics. C1 Univ New Mexico, Albuquerque, NM 87106 USA. Max Planck Inst Polymer Res, Mainz, Germany. Univ Utah, Dept Mat Sci & Engn, Salt Lake City, UT 84112 USA. Univ Utah, Dept Chem & Fuels Engn, Salt Lake City, UT 84112 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Curro, JG (reprint author), Univ New Mexico, Albuquerque, NM 87106 USA. NR 50 TC 31 Z9 31 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 22 PY 2001 VL 115 IS 12 BP 5669 EP 5678 DI 10.1063/1.1397333 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 472YZ UT WOS:000171013700041 ER PT J AU Walters, KA Dattelbaum, DM Ley, KD Schoonover, JR Meyer, TJ Schanze, KS AF Walters, KA Dattelbaum, DM Ley, KD Schoonover, JR Meyer, TJ Schanze, KS TI Photophysics of phenyleneethynylene metal-organic oligomers. Probing the lowest excited state by time-resolved IR spectroscopy SO CHEMICAL COMMUNICATIONS LA English DT Article ID CONJUGATED POLYMERS; COMPLEXES; RHENIUM(I) AB The long-lived excited state in a series of metal-organic phenyleneethynylene oligomers is probed by UV-visible and infrared transient absorption spectroscopy. C1 Univ Florida, Dept Chem, Gainesville, FL 32611 USA. Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87544 USA. RP Schanze, KS (reprint author), Univ Florida, Dept Chem, POB 117200, Gainesville, FL 32611 USA. RI Schanze, Kirk/A-7200-2009; OI Schanze, Kirk/0000-0003-3342-4080; Walters, Keith/0000-0002-5997-1579 NR 16 TC 24 Z9 24 U1 2 U2 11 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD SEP 21 PY 2001 IS 18 BP 1834 EP 1835 DI 10.1039/b105124p PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 477ML UT WOS:000171287300064 PM 12240338 ER PT J AU Siegel, RW Jain, R Bradbury, A AF Siegel, RW Jain, R Bradbury, A TI Using an in vivo phagemid system to identify non-compatible loxP sequences (vol 499, pg 147, 2001) SO FEBS LETTERS LA English DT Correction ID SITE-SPECIFIC RECOMBINATION; CRE-MEDIATED RECOMBINATION; AFFINITY HUMAN-ANTIBODIES; MAMMALIAN-CELLS; TRANSGENIC MICE; SPACER REGION; DNA; REPLACEMENT; INTEGRATION; ACTIVATION AB The site-specific recombination system of bacteriophage P1 is composed of the Cre recombinase that recognizes a 34-bp loxP site. The CrelloxP system has been extensively used to manipulate eukaryotic genomes for functional genomic investigations. The creation of additional heterologous loxP sequences potentially expands the utility of this system, but only if these loxP sequences do not recombine with one another. We have developed a stringent in vivo assay to examine the degree of recombination between all combinations of each previously published heterologous loxP sequence. As expected, homologous loxP sequences efficiently underwent Cre-mediated recombination. However, many of the heterologous loxP pairs were able to support recombination with rates varying from 5 to 100%. Some of these loxP sequences have previously been reported to be noncompatible with one another. Our study also confirmed other heterologous loxP pairs that had previously been shown to be non-compatible, as well as defined additional combinations that could be used in designing new recombination vectors. (C) 2001 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Biosci Div, Los Alamos, NM 87545 USA. SISSA, Int Sch Adv Studies, I-34014 Trieste, Italy. RP Bradbury, A (reprint author), Los Alamos Natl Lab, Biosci Div, MS-M888, Los Alamos, NM 87545 USA. OI Siegel, Robert/0000-0002-0833-5580 NR 25 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0014-5793 J9 FEBS LETT JI FEBS Lett. PD SEP 21 PY 2001 VL 505 IS 3 BP 466 EP 473 DI 10.1016/S0014-5793(01)02805-8 PG 8 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 477FM UT WOS:000171272500026 ER PT J AU An, XL Takakuwa, Y Manno, S Han, BG Gascard, P Mohandas, N AF An, XL Takakuwa, Y Manno, S Han, BG Gascard, P Mohandas, N TI Structural and functional characterization of protein 4.1R-phosphatidylserine interaction - Potential role in 4.1R sorting within cells SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID SPECTRIN-ACTIN BINDING; ERYTHROCYTE-MEMBRANE; PHOSPHATIDYLINOSITOL 4,5-BISPHOSPHATE; TERNARY COMPLEX; GLYCOPHORIN-C; BANDS 2.1; CALMODULIN; SITE; DOMAIN; IDENTIFICATION AB Erythrocyte protein 4.1R is a multifunctional protein that binds to various membrane proteins and to phosphatidylserine. In the present study, we report two important observations concerning 4.1R-phosphatidylserine interaction. Biochemically, a major finding of the present study is that 4.1R binding to phosphatidylserine appears to be a two-step process in which 4.1R first interacts with serine head group of phosphatidylserine through the positively charged amino acids YKRS and subsequently forms a tight hydrophobic interaction with fatty acid moieties. 4.1R failed to dissociate from phosphatidylserine liposomes under high ionic strength but could be released specifically by phospholipase A(2) but not by phospholipase C or D. Biochemical analyses showed that acyl chains were associated with 4.1R released by phospholipase A(2). Importantly, the association of acyl chains with 4.1R impaired its ability to interact with calmodulin, band 3, and glycophorin C. Removal of acyl chains restored 4.1R binding. These data indicate that acyl chains of phosphatidylserine play an important role in its interaction with 4.1R and on 4.1R function. In terms of biological significance, we have obtained evidence that 4.1R-phosphatidylserine interaction may play an important role in cellular sorting of 4.1R. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. Tokyo Womens Med Univ, Dept Biochem, Sch Med, Shinjuku Ku, Tokyo 1628666, Japan. RP Mohandas, N (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Mail Stop 74hy157,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Han, Bong-Gyoon/J-9120-2012 FU NIDDK NIH HHS [DK 26263, DK 32094, DK 56355] NR 43 TC 40 Z9 41 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD SEP 21 PY 2001 VL 276 IS 38 BP 35778 EP 35785 DI 10.1074/jbc.M101364200 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 474LU UT WOS:000171109300075 PM 11423550 ER PT J AU Kaminker, PG Kim, SH Taylor, RD Zebarjadian, Y Funk, WD Morin, GB Yaswen, P Campisi, J AF Kaminker, PG Kim, SH Taylor, RD Zebarjadian, Y Funk, WD Morin, GB Yaswen, P Campisi, J TI TANK2, a new TRF1-associated poly(ADP-ribose) polymerase, causes rapid induction of cell death upon overexpression SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID NUCLEAR-MATRIX; REPLICATIVE SENESCENCE; TELOMERE LENGTH; HUMAN FIBROBLASTS; TANKYRASE; PROTEIN; INHIBITION; MOUSE; DNA; CENTROSOMES AB Tankyrase (TANK1) is a human telomere-associated poly(ADP-ribose) polymerase (PARP) that binds the telomere-binding protein TRF1 and increases telomere length when overexpressed. Here we report characterization of a second human tankyrase, tankyrase 2 (TANK2), which can also interact with TRF1 but has properties distinct from those of TANK1. TANK2 is encoded by a 66-kilobase pair gene (TNKS2) containing 28 exons, which express a 6.7-kilobase pair mRNA and a 1166-amino acid protein. The protein shares 85% amino acid identity with TANK1 in the ankyrin repeat, sterile a-motif, and PARP catalytic domains but has a unique N-terminal domain, which is conserved in the murine TNKS2 gene. TANK2 interacted with TRF1 in yeast and in vitro and localized predominantly to a perinuclear region, similar to the properties of TANK1. In contrast to TANK1, however, TANK2 caused rapid cell death when highly overexpressed. TANK2-induced death featured loss of mitochondrial membrane potential, but not PARP1 cleavage, suggesting that TANK2 kills cells by necrosis. The cell death was prevented by the PARP inhibitor 3-aminobenzamide. lit vivo, TANK2 may differ from TANK1 in its intrinsic or regulated PARP activity or its substrate specificity. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Geron Corp, Menlo Pk, CA 94025 USA. RP Campisi, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Mailstop 84-171,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Tang, Macy/B-9798-2014; Morin, Gregg/E-9123-2012 OI Morin, Gregg/0000-0001-8949-4374 FU NIA NIH HHS [AG00266, AG09909] NR 48 TC 157 Z9 169 U1 0 U2 11 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD SEP 21 PY 2001 VL 276 IS 38 BP 35891 EP 35899 DI 10.1074/jbc.M105968200 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 474LU UT WOS:000171109300089 PM 11454873 ER PT J AU Waszczuk, P Wieckowski, A Zelenay, P Gottesfeld, S Coutanceau, C Leger, JM Lamy, C AF Waszczuk, P Wieckowski, A Zelenay, P Gottesfeld, S Coutanceau, C Leger, JM Lamy, C TI Adsorption of CO poison on fuel cell nanoparticle electrodes from methanol solutions: a radioactive labeling study SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE electrocatalysis; methanol; platinum; ruthenium; electronic modification; radioactive labeling ID PT-RU ALLOYS; CARBON-MONOXIDE; PLATINUM-ELECTRODE; SURFACE-STRUCTURE; FORMIC-ACID; OXIDATION; ELECTROOXIDATION; ELECTROCATALYSIS; RUTHENIUM; TRANSPORTATION AB Combined radioactive labeling and electrochemical measurements were conducted to study adsorption and desorption of methanol-derived surface CO on fuel-cell grade platinum and platinum-ruthenium alloy nanoparticle catalysts. The adsorption results were obtained under constant potential and voltammetric conditions, and the experiments were carried out in sulfuric acid solutions containing methanol (at room temperature). The electrode potential effect on the CO coverage, the rates of methanol adsorption and CO desorption, as well as the susceptibility of the CO adsorbate to exchange with bulk methanol (surface/bulk exchange) were investigated. We found that CO adsorption at low electrode potentials was slower than at higher potentials, but higher coverages were obtained at the low potentials. Adsorption, desorption and surface/bulk exchange processes were significantly different on Pt than on Pt/Ru, confirming some of the previous results published in the electrochemical literature. The higher rate of methanol adsorption on Pt/Ru is explained on the basis of electronic modification of platinum by ruthenium using state-of-the-art concepts from the theory of electrocatalytic reactivity. We also report that combined bifunctional and ligand effects account for the difference in desorption kinetics. Finally, the relevance of our observations to the processes occurring on the anode of the direct methanol oxidation fuel cell is highlighted. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Illinois, Dept Chem, Urbana, IL 61801 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Poitiers, CNRS, UMR 6503, Lab Equipe Electrocatalyse, F-86022 Poitiers, France. RP Wieckowski, A (reprint author), Univ Illinois, Dept Chem, 1209 W Calif St, Urbana, IL 61801 USA. RI LEGER, Jean-Michel/D-1125-2013 OI LEGER, Jean-Michel/0000-0002-9879-5029 NR 58 TC 128 Z9 129 U1 3 U2 28 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD SEP 21 PY 2001 VL 511 IS 1-2 BP 55 EP 64 DI 10.1016/S0022-0728(01)00559-9 PG 10 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA 479MM UT WOS:000171408200008 ER PT J AU Xing, EP Wolf, DM Dubchak, I Spengler, S Zorn, M Muchnik, I Kulikowski, C AF Xing, EP Wolf, DM Dubchak, I Spengler, S Zorn, M Muchnik, I Kulikowski, C TI Automatic discovery of sub-molecular sequence domains in multi-aligned sequences: A dynamic programming algorithm for multiple alignment segmentation SO JOURNAL OF THEORETICAL BIOLOGY LA English DT Article ID RIBOSOMAL-RNA STRUCTURES; 16S AB Automatic identification of sub-structures in multi-aligned sequences is of great importance for effective and objective structural/functional domain annotation, phylogenetic treeing and other molecular analyses. We present a segmentation algorithm that optimally partitions a given multi-alignment into a set of potentially biologically significant blocks, or segments. This algorithm applies dynamic programming and progressive optimization to the statistical profile of a multi-alignment in order to optimally demarcate relatively homogenous subregions. Using this algorithm, a large multi-alignment of eukaryotic 16S rRNA was analyzed. Three types of sequence patterns were identified automatically and efficiently: shared conserved domain; shared variable motif, and rare signature sequence. Results were consistent with the patterns identified through independent phylogenetic and structural approaches. This algorithm facilitates the automation of sequence-based molecular structural and evolutionary analyses through statistical modeling and high performance computation. (C) 2001 Academic Press. C1 Lawrence Berkeley Natl Lab, NERSC, Ctr Bioinformat & Computat Genom, Berkeley, CA 94720 USA. Rutgers State Univ, Dept Comp Sci, Piscataway, NJ 08855 USA. Rutgers State Univ, DIMACS, Piscataway, NJ 08855 USA. RP Xing, EP (reprint author), Univ Calif Berkeley, Div Comp Sci, 593 Soda Hall, Berkeley, CA 94706 USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-5193 J9 J THEOR BIOL JI J. Theor. Biol. PD SEP 21 PY 2001 VL 212 IS 2 BP 129 EP 139 DI 10.1006/jtbi.2001.2319 PG 13 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA 473UX UT WOS:000171067400001 PM 11531380 ER PT J AU Drinkwater, MJ Gregg, MD Holman, BA Brown, MJI AF Drinkwater, MJ Gregg, MD Holman, BA Brown, MJI TI The evolution and star formation of dwarf galaxies in the Fornax Cluster SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE stars : formation; galaxies : dwarf; galaxies : evolution; galaxies : clusters : individual : Fornax ID SURFACE-BRIGHTNESS GALAXIES; VIRGO CLUSTER; ELLIPTICAL GALAXIES; CATALOG; PHOTOMETRY; SPECTROSCOPY; FIELD; VELOCITIES; POPULATION; SAMPLE AB We present the results of a spectroscopic survey of 675 bright (16.5 < b(J) < 18) galaxies in a 6 degrees field centred on the Fornax cluster with the FLAIR-II spectrograph on the UK Schmidt Telescope. Three galaxy samples were observed: compact galaxies to search for new blue compact dwarfs, candidate M 32-like compact dwarf ellipticals, and a subset of the brightest known cluster members in order to study the cluster dynamics. We measured redshifts for 516 galaxies, of which 108 were members of the Fornax Cluster. Defining dwarf galaxies to be those with b(J) greater than or equal to 15 (M-B greater than or equal to - 16.5), there are a total of 62 dwarf cluster galaxies in our sample. Nine of these are new cluster members previously misidentified as background galaxies. The cluster dynamics show that the dwarf galaxies are still falling into the cluster whereas the giants are virialized. We classified the observed galaxies as late-type if we detected H alpha emission at an equivalent width greater than 1 Angstrom. The spectra were obtained through fixed apertures, so they reflect activity in the galaxy cores, but this does not significantly bias the classifications of the compact dwarfs in our sample. The new classifications reveal a higher rate of star formation among the dwarf galaxies than suggested by morphological classification: 35 per cent have significant H alpha emission indicative of star formations but only 19 per cent were morphologically classified as late-types. The star-forming dwarf galaxies span the full range of physical sizes and we find no evidence in our data for a distinct class of star-forming blue compact dwarf (BCD) galaxy. The distribution of scale sizes is consistent with evolutionary processes which transform late-type dwarfs to early-type dwarfs. The fraction of dwarfs with active star formation drops rapidly towards the cluster centre: this is the usual density-morphology relation confirmed here for dwarf galaxies. The star-forming dwarfs are concentrated in the outer regions of the cluster, the most extreme in an infalling subcluster. We estimate gas depletion time-scales for five dwarfs with detected Hi emission: these are long (of order 10(10) yr), indicating that an active gas removal process must be involved if they are transformed into gas-poor dwarfs as they fall further into the cluster. Finally, in agreement with our previous results, we find no compact dwarf elliptical (M 32-like) galaxies in the Fornax Cluster. C1 Univ Melbourne, Sch Phys, Parkville, Vic 3010, Australia. Univ Calif Davis, Dept Phys, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Natl Opt Astron Observ, Tucson, AZ 85726 USA. RP Drinkwater, MJ (reprint author), Univ Melbourne, Sch Phys, Parkville, Vic 3010, Australia. RI Drinkwater, Michael/A-2201-2008; Brown, Michael/B-1181-2015; OI Drinkwater, Michael/0000-0003-4867-0022; Brown, Michael/0000-0002-1207-9137; Holman, Brett/0000-0001-6489-2798 NR 57 TC 71 Z9 71 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 21 PY 2001 VL 326 IS 3 BP 1076 EP 1094 DI 10.1046/j.1365-8711.2001.04646.x PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 477YP UT WOS:000171314400025 ER PT J AU Branchini, E Freudling, W Da Costa, LN Frenk, CS Giovanelli, R Haynes, MP Salzer, JJ Wegner, G Zehavi, I AF Branchini, E Freudling, W Da Costa, LN Frenk, CS Giovanelli, R Haynes, MP Salzer, JJ Wegner, G Zehavi, I TI Comparing the SFI peculiar velocities with the PSCz gravity field: a VELMOD analysis SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : clusters : general; galaxies : distances and redshifts; cosmology : observations; cosmology : theory; large-scale structure of Universe ID TULLY-FISHER RELATION; CATALOG-REDSHIFT-SURVEY; SCALE POWER SPECTRUM; DENSITY FIELDS; LIKELIHOOD ANALYSIS; SAMPLE SELECTION; NEARBY GALAXIES; SC GALAXIES; LOCAL-GROUP; JY SURVEY AB We compare the peculiar velocities derived from the I-band Tully-Fisher (TF) relation for 989 field spiral galaxies in the SFI catalogue with the predicted velocity field derived from the IRAS PSCz galaxy redshift survey. We assume linear gravitational instability theory and apply the maximum likelihood technique, VELMOD to SFI galaxies within a redshift cz(LG) = 6000 km s(-1). The resulting calibration of the TF relation is consistent with a previous, independent calibration for a similar sample of spirals residing in clusters. Our analysis provides an accurate estimate of the quantity beta (1) = Omega (0.6)(m)/b(1), where b(1) is the linear biasing parameter for IRAS galaxies. Using the forward TF relation and smoothing the predicted velocity field with a Gaussian filter of radius 300 km s(-1), we obtain beta (1) = 0.42 +/- 0.04 (1 sigma, uncertainty). This value, as well as other parameters in the fit, are robust to varying the smoothing radius to 500 km s(-1) and splitting the sample into spherical shells in redshift space. The one exception is the small-scale velocity dispersion, sigma (v), which varies from similar to 200 km s(-1) (within cz(LG) = 4000 km s(-1)) to similar to 500 km s(-1) at larger distance. For beta (1) similar or equal to 0.42, the residuals between the TF data and the PSCz gravity field are uncorrelated, indicating that the model provides a good fit to the data. More generally, a chi (2) statistic indicates that the PSCz model velocity field provides an acceptable (3 sigma) fit to the data for 0.3 < (1) < 0.5. C1 Univ Groningen, Kapteyn Inst, NL-9700 Groningen, Netherlands. Univ Roma Tre, Dipartimento Fis, I-00146 Rome, Italy. Space Telescope European Coordinating Facil, D-85748 Garching, Germany. European So Observ, D-85748 Garching, Germany. Univ Durham, Dept Phys, Durham DH1 3LE, England. Cornell Univ, Ctr Radiophys & Space Res, Ithaca, NY 14853 USA. Cornell Univ, Natl Astron & Ionosphere Ctr, Ithaca, NY 14853 USA. Wesleyan Univ, Dept Astron, Middletown, CT 06457 USA. Dartmouth Coll, Dept Phys & Astron, Hanover, NH 03755 USA. Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Grp, Batavia, IL 60510 USA. RP Branchini, E (reprint author), Univ Groningen, Kapteyn Inst, Landleven 12,POB 800, NL-9700 Groningen, Netherlands. OI Branchini, Enzo/0000-0002-0808-6908 NR 51 TC 31 Z9 31 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 21 PY 2001 VL 326 IS 3 BP 1191 EP 1204 DI 10.1046/j.1365-8711.2001.04671.x PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 477YP UT WOS:000171314400037 ER PT J AU Haber, C AF Haber, C TI The discovery of the top quark: instruments and methods SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT Imaging 2000 Conference CY JUN 27-JUL 01, 2000 CL STOCKHOLM, SWEDEN SP Nobel Inst Phys, ACREO, Detect Technol Inc, MAMEA Imaging AB, Pixel Vis Technol Inc, Sectra AB, SINTEF Electr & Cybernet DE top quark; CDF; D0; silicon detector; vertex detector; jet spectroscopy ID PRODUCTION CROSS-SECTION; SILICON VERTEX DETECTOR; P(P)OVER-BAR COLLISIONS; COLLIDER DETECTOR; T(T)OVER-BAR PRODUCTION; PAIR PRODUCTION; HADRONIC COLLISIONS; DILEPTON EVENTS; ROOT-S=1.8 TEV; MASS AB The discovery of the top quark utilized a number of new methods and instruments. These include radiation hard silicon tracking detectors, b quark tagging the use of jets in mass reconstruction, and various kinematical analyses. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM chaber@LBL.GOV NR 36 TC 1 Z9 1 U1 1 U2 1 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 SEP 21 PY 2001 VL 471 IS 1-2 BP 12 EP 17 DI 10.1016/S0168-9002(01)00909-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 476BN UT WOS:000171206500005 ER PT J AU De Geronimo, G O'Connor, P Radeka, V Yu, B AF De Geronimo, G O'Connor, P Radeka, V Yu, B TI Front-end electronics for imaging detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT Imaging 2000 Conference CY JUN 27-JUL 01, 2000 CL STOCKHOLM, SWEDEN SP Nobel Inst Phys, ACREO, Detect Technol Inc, MAMEA Imaging AB, Pixel Vis Technol Inc, Sectra AB, SINTEF Electr & Cybernet ID ACTIVE-MATRIX READOUT; X-RAY SPECTROSCOPY; PROTEIN CRYSTALLOGRAPHY; PIXEL DETECTORS; LOW-NOISE; SYNCHROTRON-RADIATION; CHARGE PREAMPLIFIER; CMOS PREAMPLIFIER; SILICON; SYSTEM AB Front-end electronics for imaging detectors with large numbers of pixels (10(5)-10(7)) is reviewed. The noise limits as a. function of detector capacitance and power dissipation are presented for CMOS technology. Active matrix flat panel imagers (AMFPIs) are discussed and their potential noise performance is illustrated. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Instrumentat Div, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Instrumentat Div, Bldg 535B, Upton, NY 11973 USA. EM radeka@bnl.gov NR 40 TC 33 Z9 33 U1 3 U2 7 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 SEP 21 PY 2001 VL 471 IS 1-2 BP 192 EP 199 DI 10.1016/S0168-9002(01)00963-9 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 476BN UT WOS:000171206500038 ER PT J AU Moses, WW AF Moses, WW TI Trends in PET imaging SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT Imaging 2000 Conference CY JUN 27-JUL 01, 2000 CL STOCKHOLM, SWEDEN SP Nobel Inst Phys, ACREO, Detect Technol Inc, MAMEA Imaging AB, Pixel Vis Technol Inc, Sectra AB, SINTEF Electr & Cybernet DE PET; PET instrumentation ID LUTETIUM OXYORTHOSILICATE; DETECTOR; RESOLUTION; DEPTH; SCINTILLATOR; SCANNER; DESIGN; CAMERA; FIBERS; BLOCK AB Positron Emission Tomography (PET) imaging is a well established method for obtaining information on the status of certain organs within the human body or in animals. This paper presents an overview of recent trends in PET instrumentation. Significant effort is being expended to develop new PET detector modules, especially those capable of measuring the depth of interaction. This is aided by recent advances in scintillator and pixellated photodetector technology. The other significant area of effort is in the development of special purpose PET cameras (such as for imaging breast cancer or small animals) or cameras that have the ability to image in more than one modality (such as PET/SPECT or PET/X-ray CT). (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Moses, WW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Mailstop 55-121,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 33 TC 62 Z9 63 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD SEP 21 PY 2001 VL 471 IS 1-2 BP 209 EP 214 DI 10.1016/S0168-9002(01)00969-X PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 476BN UT WOS:000171206500041 ER PT J AU Pitts, WK Martin, MD AF Pitts, WK Martin, MD TI Experience with laser microfabricated detectors at the University of Louisville SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT Imaging 2000 Conference CY JUN 27-JUL 01, 2000 CL STOCKHOLM, SWEDEN SP Nobel Inst Phys, ACREO, Detect Technol Inc, MAMEA Imaging AB, Pixel Vis Technol Inc, Sectra AB, SINTEF Electr & Cybernet DE detector; gas proportional counter; X-ray; microfabrication ID GASEOUS DETECTORS AB We have designed, produced, and tested several different types, of micropatterned gas proportional counters at the University of Louisville. A particular specialty has been the development and application of laser micromachining techniques to produce devices as the Microwell, GEM, and Microtube. Laser micromachining is a new technology with particular advantages for detector fabrication, including the ability to produce novel structures, machine wells in thick substrates, and produce detector arrays well suited to inclusion in modern microelectronics components. We report here the development of the Microwell detector and laser micromachining techniques for its production. First results are also presented for the Microtube detector, a device with a reduced anode formed as a tube extending into the center of the well. (C) 2001 Elsevier Science B.V. Ali rights reserved. C1 Univ Louisville, Dept Phys, Louisville, KY 40292 USA. RP Pitts, WK (reprint author), Pacific NW Natl Lab, MSIN P8-20,POB 999, Richland, WA 99352 USA. NR 13 TC 1 Z9 1 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 SEP 21 PY 2001 VL 471 IS 1-2 BP 268 EP 271 DI 10.1016/S0168-9002(01)01000-2 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 476BN UT WOS:000171206500052 ER PT J AU Gillooly, JF Brown, JH West, GB Savage, VM Charnov, EL AF Gillooly, JF Brown, JH West, GB Savage, VM Charnov, EL TI Effects of size and temperature on metabolic rate SO SCIENCE LA English DT Article AB We derive a general model, based on principles of biochemical kinetics and allometry, that characterizes the effects of temperature and body mass on metabolic rate. The model fits metabolic rates of microbes, ectotherms, endotherms; (including those in hibernation), and plants in temperatures ranging from 0 degrees to 40 degreesC. Mass- and temperature-compensated resting metabolic rates of all organisms are similar: The lowest (for unicellular organisms and plants) is separated from the highest (for endothermic vertebrates) by a factor of about 20. Temperature and body size are primary determinants of biological time and ecological roles. C1 Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. Santa Fe Inst, Santa Fe, NM 87501 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Gillooly, JF (reprint author), Univ New Mexico, Dept Biol, Albuquerque, NM 87131 USA. RI Langerhans, R./A-7205-2009 NR 12 TC 1278 Z9 1325 U1 91 U2 868 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 21 PY 2001 VL 293 IS 5538 BP 2248 EP 2251 DI 10.1126/science.1061967 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 475AL UT WOS:000171139400042 PM 11567137 ER PT J AU Kostecki, R Schnyder, B Alliata, D Song, X Kinoshita, K Kotz, R AF Kostecki, R Schnyder, B Alliata, D Song, X Kinoshita, K Kotz, R TI Surface studies of carbon films from pyrolyzed photoresist SO THIN SOLID FILMS LA English DT Article DE atomic force microscopy; carbon; Raman scattering; X-ray photoelectron spectroscopy ID DIAMOND-LIKE CARBON; HEAT-TREATMENT TEMPERATURES; LITHIUM-ION BATTERIES; AMORPHOUS-CARBON; RAMAN-SPECTRA; DEPOSITION; GRAPHITE; ANODES; ARC AB Positive and negative photoresists, which are commonly used in the semiconductor industry, were deposited on silicon wafers by spin coating and then pyrolyzed at temperatures of 600-1100 degreesC in an inert environment to produce thin carbon films. Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning probe microscopy involving current-sensing atomic force microscopy (CS-AFM) were utilized to characterize the properties of the carbon films. Raman spectroscopy showed two broad bands at approximately 1360 cm(-1) and 1600 cm(-1), which deconvoluted to four Gaussian bands. The origin of these bands is discussed. CS-AFM showed that the surface conductance increased with increased pyrolysis temperature, and the results are consistent with measurements by a four-point probe method. The XPS spectra revealed the presence of oxygen functional groups (C=O and C-O) on the carbon surface. The relative fraction of oxygen, O/C ratio, decreased as the pyrolysis temperature increased, in agreement with published results. The full-width at half-maximum of the C-1s peak obtained by XPS also decreased with increasing pyrolysis temperature. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Paul Scherrer Inst, Lab Electrochem, CH-5232 Villigen, Switzerland. RP Kinoshita, K (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 42 TC 111 Z9 116 U1 1 U2 43 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 21 PY 2001 VL 396 IS 1-2 BP 36 EP 43 DI 10.1016/S0040-6090(01)01185-3 PG 8 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 485FM UT WOS:000171742900007 ER PT J AU Hu, J Snell, AJ Hajto, J Rose, MJ Edmiston, W AF Hu, J Snell, AJ Hajto, J Rose, MJ Edmiston, W TI Field-induced anomalous changes in Cr/a-Si : H/V thin film structures SO THIN SOLID FILMS LA English DT Article DE field-induced; anomalous changes; Cr/a-Si : H/V; thin film structures ID AMORPHOUS-SILICON; DEVICES; TRANSITION AB Experimental results on the electronic properties of conditioned Cr/hydrogenated amorphous silicon (a-Si:H)/V thin film devices are presented. The devices under test were electro-formed, and had resistances in the range from several hundred Ohms to several kiloOhms. The current of conditioned devices varied non-linearly with bias at low voltages, but exhibited 'jumps' at a threshold voltage (V-th) (typically 2-3 V), leading to a resistance change of one to three orders of magnitude. Above V-th the current increased almost linearly with bias, and the carrier transport changed from a semiconducting behaviour to a more conducting (metallic) state. This was confirmed by a.c. characteristics of the conditioned devices, which showed a transition from a capacitive to an inductive behaviour around V-th. The threshold voltage V-th, was found to decrease with increasing temperature and disappeared at 340-350 K, but recovered when the temperature was reduced. The transition at V-th has been analysed in terms of an electrothermal mechanism. The calculated turnover temperature is approximately 346 K, close to that for the disappearance of Vh. We suggest that the observed transition could involve vanadium oxides such as VO2. The phase transition could also facilitate the underlying 'quantisation' effect. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Napier Polytech, Sch Engn, Edinburgh EH10 5DT, Midlothian, Scotland. Univ Edinburgh, Dept Elect Engn, Edinburgh EH9 3JL, Midlothian, Scotland. Univ Dundee, Dept Appl Phys & Elect & Mfg Engn, Dundee DD1 4HN, Scotland. RP Hu, J (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 33 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 21 PY 2001 VL 396 IS 1-2 BP 240 EP 249 PG 10 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 485FM UT WOS:000171742900036 ER PT J AU Lee, EH Byun, TS Hunn, JD Yoo, MH Farrell, K Mansur, LK AF Lee, EH Byun, TS Hunn, JD Yoo, MH Farrell, K Mansur, LK TI On the origin of deformation microstructures in austenitic stainless steel: Part I - Microstructures SO ACTA MATERIALIA LA English DT Article DE steels (austenite); deformation; microstructure ID IRRADIATED STEELS; MECHANISMS; CRYSTALS; ALLOYS; PROTON AB A comprehensive characterization of room temperature deformation microstructures was carried out by transmission electron microscopy for ion irradiated and deformed AISI 316LN austenitic stainless steel. Deformation microstructures were produced by a recently developed disk-bend test method and also by a uniaxial tensile test. Cross-slip was dramatically suppressed by the radiation-induced defects and slip occurred predominantly by planar glide of Shockley partial dislocations. Deformed microstructures consisted of piled-up dislocations, nanotwin layers, stacking faults, and defect-reduced dislocation channel bands. Analyses revealed that all these features were different manifestations of the same type of deformation band, namely a composite of overlapping faulted layers produced by Shockley partial dislocations. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. EM farrellk@ornl.gov NR 24 TC 54 Z9 56 U1 0 U2 23 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD SEP 20 PY 2001 VL 49 IS 16 BP 3269 EP 3276 DI 10.1016/S1359-6454(01)00193-8 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 476VG UT WOS:000171249000014 ER PT J AU Lee, EH Yoo, MH Byun, TS Hunn, JD Farrell, K Mansur, LK AF Lee, EH Yoo, MH Byun, TS Hunn, JD Farrell, K Mansur, LK TI On the origin of deformation microstructures in austenitic stainless steel: Part II - Mechanisms SO ACTA MATERIALIA LA English DT Article DE steels (austenite); deformation mechanisms ID MARTENSITE; DEFECT AB Deformation microstructures of austenitic stainless steels consist of profuse pile-up dislocations, stacking faults, nanotwins, and defect-reduced channels as demonstrated in the Part I companion paper of this title [Acta mater., 2001, 49(16), 3269-3276]. Yet the mechanisms of such microstructural. evolution are poorly understood. Thus, a comprehensive study was conducted to understand the underlying physics of deformation in metals using radiation damage as a tool. It was found that, for energetic reasons, glide dislocations dissociated into Shockley partials during glide. Consequently, the interaction between a glide dislocation and radiation-induced defects occurs by a two-step reaction, first with the leading partial and then with the trailing partial. With this insight, the origin of deformation microstructures was explained by analyzing Shockley partial dislocations and their interactions with radiation-induced Frank loops. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Farrell, K (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 19 TC 48 Z9 49 U1 2 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD SEP 20 PY 2001 VL 49 IS 16 BP 3277 EP 3287 DI 10.1016/S1359-6454(01)00194-X PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 476VG UT WOS:000171249000015 ER PT J AU Kirkman, D Tytler, D O'Meara, JM Burles, S Lubin, D Suzuki, N Carswell, RF Turner, MS Wampler, EJ AF Kirkman, D Tytler, D O'Meara, JM Burles, S Lubin, D Suzuki, N Carswell, RF Turner, MS Wampler, EJ TI New Hubble Space Telescope spectra of QSO PG 1718+4807: No evidence for strong deuterium absorption SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; intergalactic medium; quasars : absorption lines; quasars : individual (PG 1718+4807) ID ABUNDANCE; RATIO; Z=0.7 AB The Z(abs) similar to 0.701 absorption system toward QSO PG 1718 + 4807 is the only example of a QSO absorption system which might have a deuterium/hydrogen ratio approximately 10 times the value found toward other QSOs. We have obtained new Space Telescope Imaging Spectrograph spectra from the Hubble Space Telescope of the Ly alpha and Lyman limit regions of the system. These spectra give the redshift and velocity dispersion of the neutral hydrogen, which produces most of the observed absorption. The Ly alpha line is too narrow to account for all of the observed absorption. It was previously known that extra absorption is needed on the blue side of the main H I near the expected position of deuterium. We do not find evidence in the current data that the extra absorption is entirely deuterium and find that it is more likely that some of the extra absorption is contaminating H. Until new data can be found that can independently constrain the line parameters of the potential contaminating H, it will not be possible to measure D/H in this system. Some uncertainty persists because we have a low signal-to-noise ratio and the extra absorption-be it deuterium or hydrogen-is heavily blended with the Ly alpha absorption from the main hydrogen absorption. C1 Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Univ Chicago, Enrico Fermi Inst, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Kirkman, D (reprint author), Univ Calif San Diego, Ctr Astrophys & Space Sci, MS 0424, La Jolla, CA 92093 USA. NR 9 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 SEP 20 PY 2001 VL 559 IS 1 BP 23 EP 28 DI 10.1086/322357 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 478WP UT WOS:000171371300003 ER PT J AU Koller, J Kimeswenger, S AF Koller, J Kimeswenger, S TI The anomalous infrared emission of Abell 58 SO ASTROPHYSICAL JOURNAL LA English DT Article DE circumstellar matter; dust, extinction; infrared : ISM; methods : numerical; planetary nebulae : individual (Abell 58); stars : individual (V605 Aquilae) ID TRANSIENTLY HEATED PARTICLES; POOR PLANETARY-NEBULAE; HELIUM SHELL FLASH; TEMPERATURE-FLUCTUATIONS; INTERSTELLAR GRAINS; RADIATIVE-TRANSFER; DUST PARTICLES; EVOLUTION; A58; SPECTRUM AB We present a new model to explain the excess in mid- and near-infrared emission of the central, hydrogen-poor dust knot in the planetary nebula (PN) Abell 58. Current models disagree with ISO measurements because they apply an average grain size and equilibrium conditions only. We investigate grain size distributions and temperature fluctuations affecting infrared emission using a new radiative transfer code and discuss in detail the conditions requiring an extension of the classical description. The peculiar infrared emission of V605 Aql, the central dust knot in Abell 58, has been modeled with our code. V605 Aql is of special interest as it is one of only three stars ever observed to move from the evolutionary track of a central PN star back to the post-asymptotic giant branch state. C1 Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. Los Alamos Natl Lab, Div Plasma Phys X1, Los Alamos, NM 87545 USA. Univ Innsbruck, Inst Astrophys, A-6020 Innsbruck, Austria. RP Koller, J (reprint author), Rice Univ, Dept Phys & Astron, MS-108, Houston, TX 77005 USA. EM josef@rice.edu; stefan.kimeswenger@uibk.ac.at RI Koller, Josef/C-5591-2009; Kimeswenger, of/K-7393-2013 OI Koller, Josef/0000-0002-6770-4980; NR 38 TC 13 Z9 13 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 20 PY 2001 VL 559 IS 1 BP 419 EP 423 DI 10.1086/322407 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 478WP UT WOS:000171371300039 ER PT J AU Almeida, AL Martins, JBL Longo, E Furtado, NC Taft, CA Sambrano, JR Lester, WA AF Almeida, AL Martins, JBL Longo, E Furtado, NC Taft, CA Sambrano, JR Lester, WA TI Theoretical study of MgO(001) surfaces: Pure, doped with Fe, Ca, and Al, and with and without adsorbed water SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article DE MgO; ab initio; water adsorption; Fe; Ca; Al; theoretical study ID TEMPERATURE-PROGRAMMED DESORPTION; LARGE CLUSTER-MODELS; MAGNESIUM-OXIDE; MGO SURFACES; AB-INITIO; MGO(100) SURFACE; ZNO SURFACES; DISSOCIATIVE ADSORPTION; HYDROGEN MOLECULE; PROPYLENE-OXIDE AB Ab initio calculations of large cluster models have been performed in order to study water adsorption at the five-fold coordinated adsorption site on pure Mg(001) and MgO(001) surfaces doped with Fe, Ca, and Al. The geometric parameters of the adsorbed water molecule have been optimized preparatory to analysis of binding energies, charge transfer, preferential sites of interaction, and bonding distances. We have used Mulliken population analysis methods in order to analyze charge distributions and the direction of charge transfer. We have also investigated energy gaps, HOMO energies, and SCF orbital energies as well as the acid-base properties of our cluster model. Numerical results are compared, where possible, with experiment and interpreted in the framework of various analytical models. (C) 2001 John Wiley & Sons, Inc. C1 Ctr Brasileiro Pesquisas Fis, Dept Mat Condensada & Fis Estatist, BR-22290180 Rio De Janeiro, Brazil. Univ Estado Bahia, Dept Ciencias Exatas & Terra, BR-41195001 Salvador, BA, Brazil. Univ Brasilia, Inst Quim, BR-70919970 Brasilia, DF, Brazil. Univ Fed Sao Carlos, Dept Quim, BR-3565905 Sao Carlos, SP, Brazil. Univ Estadual Paulista, Dept Matemat, BR-17033360 Sao Paulo, Brazil. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Taft, CA (reprint author), Ctr Brasileiro Pesquisas Fis, Dept Mat Condensada & Fis Estatist, Rua Dr Xavier Sigaud 150, BR-22290180 Rio De Janeiro, Brazil. RI Sambrano, Julio/B-9434-2013; Martins, Joao/I-6226-2012; Longo, Elson/B-9395-2012 OI Martins, Joao/0000-0001-8677-3239; Longo, Elson/0000-0001-8062-7791 NR 54 TC 9 Z9 9 U1 2 U2 7 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD SEP 20 PY 2001 VL 84 IS 6 BP 705 EP 713 DI 10.1002/qua.1426 PG 9 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA 470RF UT WOS:000170884400012 ER PT J AU Shepard, R Wagner, AF Tilson, JL Minkoff, M AF Shepard, R Wagner, AF Tilson, JL Minkoff, M TI The subspace projected approximate matrix (SPAM) modification of the Davidson method SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE Davidson; matrix; eigenvalue; eigenvector; iterative; subspace; projection; Ritz; symmetric; tensor; chemistry ID CORRESPONDING EIGENVECTORS; GENERALIZED EIGENPROBLEMS; COMPUTING EIGENVALUES; ITERATIVE CALCULATION; SYMMETRIC-MATRICES; LANCZOS-ALGORITHM; PROGRAM SYSTEM; LOWEST; CHEMISTRY; COLUMBUS AB A modification of the iterative matrix diagonalization method of Davidson is presented that is applicable to the symmetric eigenvalue problem. This method is based on subspace projections of a sequence of one or more approximate matrices. The purpose of these approximate matrices is to improve the efficiency of the solution of the desired eigenpairs by reducing the number of matrix-vector products that must be computed with the exact matrix. Several applications are presented. These are chosen to show the range of applicability of the method, the convergence behavior for a wide range of matrix types. and also the wide range of approaches that may be employed to generate approximate matrices. (C) 2001 Academic Press. C1 Argonne Natl Lab, Div Chem, Theoret Chem Grp, Argonne, IL 60439 USA. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Shepard, R (reprint author), Argonne Natl Lab, Div Chem, Theoret Chem Grp, Argonne, IL 60439 USA. EM shepard@tcg.anl.gov; wagner@tcg.anl.gov; jtilson@ccr.buffalo.edu; minkoff@mcs.anl.gov NR 33 TC 8 Z9 10 U1 1 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 20 PY 2001 VL 172 IS 2 BP 472 EP 514 DI 10.1006/jcph.2001.6828 PG 43 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 477FY UT WOS:000171273600004 ER PT J AU Gentile, NA AF Gentile, NA TI Implicit Monte Carlo diffusion - An acceleration method for Monte Carlo time-dependent radiative transfer simulations SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID TRANSPORT AB Implicit Monte Carlo (IMC) is often employed to numerically simulate radiative transfer. In problems with regions that are characterized by a small mean free path, IMC can take a prohibitive amount of time, because many particle steps must be simulated to advance the particle through the time step. Problems containing regions with a small mean free path can frequently be accurately simulated much more quickly by employing the diffusion equation as an approximation. However, the diffusion approximation is not accurate in regions of the problem where the mean free path is large. We present a method for accelerating time-dependent Monte Carlo radiative transfer calculations by using a discretization of the diffusion equation to calculate probabilities that are used to advance particles in regions with small mean free paths. The method is demonstrated on problems with one-and two-dimensional orthogonal grids. It results in decreases in run time of more than an order of magnitude on these problems, while producing answers with accuracy comparable to pure IMC simulations. We call the method Implicit Monte Carlo Diffusion, which we abbreviate IMD. (C) 2001 Academic Press. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Gentile, NA (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 19 TC 51 Z9 52 U1 0 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 20 PY 2001 VL 172 IS 2 BP 543 EP 571 DI 10.1006/jcph.2001.6836 PG 29 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 477FY UT WOS:000171273600006 ER PT J AU Campbell, JC Shashkov, MJ AF Campbell, JC Shashkov, MJ TI A tensor artificial viscosity using a mimetic finite difference algorithm SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID LOGICALLY RECTANGULAR GRIDS; NATURAL DISCRETIZATIONS; DIVERGENCE; GRADIENT; FLUX; CURL AB We have developed a two-dimensional tensor artificial viscosity for finite difference shock wave computations. The discrete viscosity tensor is formed by multiplying the gradient of velocity tensor by a scalar term. The scalar term is based on the form of viscosity first presented by Kurapatanko, and also contains a limiter designed to switch off the viscosity for shockless compression and rigid-body rotation. Mimetic discretizations are used to derive the form of the momentum and energy equations for a nonorthogonal grid where the viscosity tensor is evaluated at the zone edges. The advantage of the tensor viscosity is a reduction of the dependence of the solution on the relation of the g-rid to the flow structure. (C) 2001 Academic Press. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Campbell, JC (reprint author), Los Alamos Natl Lab, Los Alamos, NM 87545 USA. OI Campbell, James/0000-0001-8208-8103 NR 19 TC 107 Z9 115 U1 0 U2 5 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 20 PY 2001 VL 172 IS 2 BP 739 EP 765 DI 10.1006/jcph.2001.6856 PG 27 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 477FY UT WOS:000171273600015 ER PT J AU Mercuri, F Mundy, CJ Parrinello, M AF Mercuri, F Mundy, CJ Parrinello, M TI Formation of a reactive intermediate in molecular beam chemistry of sodium and water SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID AB-INITIO; CLUSTERS; DYNAMICS AB The aim of this work is a theoretical study of the initial steps in the reaction of sodium and water clusters in a molecular beam. Recent experimental and theoretical works have indicated that the presence of both sodium atoms and Nat dimers in the molecular beam give rise to a chemical reaction yielding sodium hydroxide and molecular hydrogen. Furthermore, experiments seem to indicate that at least three sodium atoms are present (e.g. a dimer and a solvated neutral atom). In this study, we take a step toward answering the question of why it is necessary to have three sodium atoms present to initiate the chemistry. By means of Car-Parrinello molecular dynamics simulations we investigate the formation of the dipolar reactive intermediate using a sodium dimer and a small water clusters, (H2O)(n) (n = 6, 8), as reagents. This stable reactive intermediate is then able to initiate the reaction, yielding sodium hydroxide and a sodium hydride. To our surprise, our findings indicate that that formation of the dipolar atom is a natural state of the dimer/water cluster system; lending credibility to it being the only channel for the reactive process. C1 Univ Perugia, Dipartimento Chim, I-06123 Perugia, Italy. CNR, Ctr Studio Calcolo Intensivo Sci Mol, I-06123 Perugia, Italy. RP Mundy, CJ (reprint author), Lawrence Livermore Natl Lab, L-371, Livermore, CA 94550 USA. RI Mercuri, Francesco/A-4066-2009 OI Mercuri, Francesco/0000-0002-3369-4438 NR 14 TC 22 Z9 22 U1 2 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD SEP 20 PY 2001 VL 105 IS 37 BP 8423 EP 8427 DI 10.1021/jp011046x PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 473GQ UT WOS:000171032500007 ER PT J AU Wang, BS Fockenberg, C AF Wang, BS Fockenberg, C TI Direct measurement of the rate constant for the CH2((X)over-tilde(3)B(1))+CH3 reaction at 300 K SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID EVALUATED KINETIC DATA; 193 NM; PRESSURE-DEPENDENCE; STATE DISTRIBUTIONS; METHYL RADICALS; GAS-PHASE; ACETONE; RECOMBINATION; TEMPERATURE; PHOTOLYSIS AB The kinetics of the reaction of ground-state methylene radicals ((X) over tilde B-3(1), (CH2)-C-3) with methyl radicals (CH3) has been investigated. Both radicals were produced by the photolysis of acetone (CH3C(O)CH3) at 193 nm. Using time-resolved time-of-flight mass spectrometry, the temporal evolution of the concentration of reactants as well as products could be observed simultaneously. Rate coefficients at T = (300 +/- 3) K with a bath gas (He) pressure of P = 133 Pa (1 Torr) for (CH2)-C-3 + CH3 (1) and CH3 + CH3 (2) have been determined to be: k(1) = (2.1 +/- 0.7) x 10(-10) cm(3) molecule(-1) s(-1) and k(2) = (4.6 +/- 1.0) x 10(-11) cm(3) molecule(-1) s(-1), respectively. C1 Brookhaven Natl Lab, Chem Dept 555A, Upton, NY 11973 USA. RP Fockenberg, C (reprint author), Brookhaven Natl Lab, Chem Dept 555A, Upton, NY 11973 USA. NR 30 TC 14 Z9 14 U1 1 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD SEP 20 PY 2001 VL 105 IS 37 BP 8449 EP 8455 DI 10.1021/jp011350q PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 473GQ UT WOS:000171032500012 ER PT J AU Matyushov, DV Newton, MD AF Matyushov, DV Newton, MD TI Understanding the optical band shape: Coumarin-153 steady-state spectroscopy SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Review ID ELECTRON-TRANSFER REACTIONS; SOLVENT REORGANIZATION ENERGY; CHARGE-TRANSFER REACTIONS; PUSH-PULL CHROMOPHORES; RADICAL-ION PAIRS; SOLVATION DYNAMICS; PERTURBATION-THEORY; DIPOLE SOLVATION; RESONANCE RAMAN; NONEQUILIBRIUM SOLVATION AB We have developed a band-shape analysis of optical transitions in polarizable chromophores characterized by large magnitudes of the transition dipole (intense transitions). The model is tested on steady-state spectra of the coumarin-153 optical dye, employing an explicit solvent description accounting for dipole moment, quadrupole moment, and polarizability of the solvent molecules. The calculations are performed for solvents ranging from nondipolar to strongly dipolar. The solvent dependence of both the experimental Stokes shift and the spectral width is satisfactorily reproduced over the whole polarity range. The optical width is shown to demonstrate a qualitatively different solvent dependence for absorption and emission. The solvent-induced absorption width increases with solvent polarity, whereas the solvent-induced emission width passes through a maximum: This is a result of non-Gaussian statistics of the energy gap fluctuations in polarizable/electronically delocalized chromophores. The total (i.e., solvent and vibrational) emission width tends to pass through a broad maximum at low solvent polarities, decreasing with solvent polarity for highly polar solvents. This results from the combined influence of a solvent-induced mixing of the vacuum adiabatic states and a decrease of the vibrational reorganization energy with increasing solvent polarity. The latter effect arises as a result of a coupling of the vibrational and solvent nuclear modes due to the electronic state occupation number difference, making the vibrational reorganization energy solvent-dependent. The study revels a breakdown of the linear relation between the solvent-induced width and Stokes shift. The model suggests that the Franck-Condon factor of intense optical lines should significantly depend on the magnitude of the transition dipole. C1 Arizona State Univ, Dept Chem & Biochem, Tempe, AZ 85287 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Matyushov, DV (reprint author), Arizona State Univ, Dept Chem & Biochem, POB 871604, Tempe, AZ 85287 USA. EM dmitrym@asu.edu; newton@bnl.gov OI Matyushov, Dmitry/0000-0002-9352-764X NR 104 TC 69 Z9 70 U1 1 U2 34 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD SEP 20 PY 2001 VL 105 IS 37 BP 8516 EP 8532 DI 10.1021/jp011074f PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 473GQ UT WOS:000171032500020 ER PT J AU Taatjes, CA Klippenstein, SJ AF Taatjes, CA Klippenstein, SJ TI Kinetic isotope effects and variable reaction coordinates in barrierless recombination reactions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRANSITION-STATE THEORY; KASSEL-MARCUS THEORY; BOND LENGTH; METHANE; TEMPERATURE; DEPENDENCE; FRAMEWORK; RADICALS AB The factors affecting kinetic isotope effects in barrierless recombination reactions are considered from the perspective of variational transition state theory (VTST). Despite the broad application of VTST methods, a general consideration of kinetic isotope effect predictions of the theory has not previously been undertaken, especially for cases where changes in the internal structure and vibrational frequencies of the fragments (i.e., the conserved modes) can be assumed to be negligible. Use of the center-of-mass separation as the reaction coordinate in such a case entails some restriction on the range of kinetic isotope effects which can be accommodated. Larger effects are possible within a variable reaction coordinate implementation of transition state theory, and the predicted kinetic isotope effects are shown to be strongly dependent on the location of the pivot point. Illustrative model calculations demonstrate the feasibility of reproducing the experimentally observed kinetic isotope effects for the CH + O-2, HCC + O-2, CH + C2H2, and CH + C2H4 reactions with realistic deviations of the pivot points from the center-of-mass. In contrast, calculations restricted to center-of-mass pivot points predict isotope effects that are even inverted. For the CH + CH4 reaction, the isotope effects appear too large to be explained by the reaction coordinate variations, and changes in the conserved modes play a key role in the observed isotope effects, as demonstrated with ab initio based TST simulations. Overall, the experimentally observed kinetic isotope effects in CH addition reactions are strongly suggestive of an optimum reaction coordinate corresponding to a pivot paint located near the center of the radical orbital. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Case Western Reserve Univ, Dept Chem, Cleveland, OH 44106 USA. RP Taatjes, CA (reprint author), Sandia Natl Labs, Combust Res Facil, Mail Stop 9055, Livermore, CA 94551 USA. OI Klippenstein, Stephen/0000-0001-6297-9187 NR 45 TC 19 Z9 19 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD SEP 20 PY 2001 VL 105 IS 37 BP 8567 EP 8578 DI 10.1021/jp011632q PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 473GQ UT WOS:000171032500025 ER PT J AU Nozik, AJ AF Nozik, AJ TI Royce W. Murray Festschrift - Editorial note SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Editorial Material C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Nozik, AJ (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Nozik, Arthur/A-1481-2012; Nozik, Arthur/P-2641-2016 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 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 20 PY 2001 VL 105 IS 37 BP 8639 EP 8639 DI 10.1021/jp012745c PG 1 WC Chemistry, Physical SC Chemistry GA 473GR UT WOS:000171032600001 ER PT J AU Schaaff, TG Shafigullin, MN Khoury, JT Vezmar, I Whetten, RL AF Schaaff, TG Shafigullin, MN Khoury, JT Vezmar, I Whetten, RL TI Properties of a ubiquitous 29 kDa Au : SR cluster compound SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; NANOCRYSTAL GOLD MOLECULES; ALKANETHIOLATE MONOLAYERS; CARBONYL CLUSTERS; ELECTRON-TRANSFER; LASER-DESORPTION; METAL CLUSTER; 3 DIMENSIONS; DYNAMICS; NANOPARTICLES AB The broad, intense peak found near 29 kDa in the laser-desorption mass-spectral abundances of various aurothiol (Au:SR) cluster compounds has been used to optimize the preferential formation of the species in that mass range. Recrystallization gives enriched fractions, on the 10 mg scale, that in several cases appear free of species outside that mass range. Elemental analysis and X-ray photoelectron spectra (XPS) confirm the absence of elements other than Au, S, C, and H, while infrared and NMR (H-1,C-13) spectra are consistent with intact thio groups. The Au 4f(7/2) XPS peak is only slightly shifted (similar to0.2 eV) and broadened from that of bulk Au(0) metal, and intense optical absorption extends far into the infrared region (0.5 eV), consistent with a metallic Au core. Recrystallized samples of the R = C4, C6, and C12 materials readily form highly diffractive crystalline films, powders, and single crystals on the scale of 10 mum, consistent with perfect ordering in > 100 nm grains, and a negligible amorphous content. Uniformity is quantified through several independent measures: (1) the mass spectrometrically determined core mass of 29.2 +/- 2 kDa is invariant to that of the thiol used, indicating an equivalent Art core diameter of 1.68 +/- 0.05 nm, assuming bulk density. (2) The powder X-ray diffraction intensities are sensitively fit to a Au core of 1.64 +/- 0.03 nm equivalent diameter. (3) The powder patterns index unambiguously to bcc packing, with nearest-neighbor distances of 2.68 +/- 0.02 nm (R = C6) and 3.15 +/- 0.02 nm (R = C12). An fcc packing structure with 2.56 +/- 0.04 nm distance (11.9 nm(3) volume) is found for R = C4. A formulation consistent with this mass spectral, diffraction, and average compositional information is Au144-146(SR)(50-60), with the structure of the inorganic core being influenced by the type of adsorbate used to produce the entire inorganic/organic assembly. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Georgia Inst Technol, Sch Chem, Atlanta, GA 30332 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. RP Schaaff, TG (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 67 TC 157 Z9 157 U1 4 U2 38 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 20 PY 2001 VL 105 IS 37 BP 8785 EP 8796 DI 10.1021/jp011122w PG 12 WC Chemistry, Physical SC Chemistry GA 473GR UT WOS:000171032600021 ER PT J AU Gerion, D Pinaud, F Williams, SC Parak, WJ Zanchet, D Weiss, S Alivisatos, AP AF Gerion, D Pinaud, F Williams, SC Parak, WJ Zanchet, D Weiss, S Alivisatos, AP TI Synthesis and properties of biocompatible water-soluble silica-coated CdSe/ZnS semiconductor quantum dots SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NANOCRYSTALS AB We describe the synthesis of water-soluble semiconductor nanoparticles and discuss and characterize their proper-ties. Hydrophobic CdSe/ZnS core/shell nanocrystals with a core size between 2 and 5 nm are embedded in a siloxane shell and functionalized with thiol and/or amine groups. Structural characterization by AFM indicates that the siloxane shell is 1-5 nm thick, yielding final particle sizes of 6-17 nm, depending on the initial CdSe core size. The silica coating does not significantly modify the optical properties of the nanocrystals. Their fluorescence emission is about 32-35 nm fwhm and can be tuned from blue to red with quantum yields up to 18%, mainly determined by the quantum yield of the underlying CdSe/ZnS nanocrystals. Silanized nanocrystals exhibit enhanced photochemical stability over organic fluorophores. They also display high stability in buffers at physiological conditions (> 150 mM NaCl). The introduction of functionalized groups onto the siloxane surface would permit the conjugation of the nanocrystals to biological entities. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Gerion, D (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Pinaud, Fabien/F-2306-2010; Zanchet, Daniela/D-6566-2012; weiss, shimon/B-4164-2009; Parak, Wolfgang J./M-3998-2014; Alivisatos , Paul /N-8863-2015 OI Zanchet, Daniela/0000-0003-1475-2548; weiss, shimon/0000-0002-0720-5426; Parak, Wolfgang J./0000-0003-1672-6650; Alivisatos , Paul /0000-0001-6895-9048 NR 32 TC 991 Z9 1008 U1 37 U2 479 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 20 PY 2001 VL 105 IS 37 BP 8861 EP 8871 DI 10.1021/jp0105488 PG 11 WC Chemistry, Physical SC Chemistry GA 473GR UT WOS:000171032600030 ER PT J AU Trammell, SA Yang, P Sykora, M Fleming, CN Odobel, F Meyer, TJ AF Trammell, SA Yang, P Sykora, M Fleming, CN Odobel, F Meyer, TJ TI Molecular energy transfer across oxide surfaces SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CHARGE-TRANSFER; ELECTRON-TRANSFER; EXCITED-STATES; METAL-COMPLEXES; THIN-FILMS; TIO2; ASSEMBLIES; DISTANCE; DYNAMICS; SPECTRA AB The decay properties of the metal-to-ligand charge transfer (MLCT) excited state(s) of [Ru(bpy)(2)(4,4 '-(PO3H2)(2-)bpy)](Br)(2) adsorbed in nanoporous, thin ZrO2 films are complex. Decay kinetics are comparable under Ar or Ar-deaerated CH3CN suggesting that the complexes are imbedded in the open porous structures of the films. Average lifetimes are dependent on the extent of fractional coverage (F-Ru(II)) and emission maxima are time dependent. A model is invoked involving complex surface relaxation dynamics arising from a heterogeneity in adsorption sites and cross-surface Ru-II*-to-Ru-II migration and quenching at low-energy trap sites. On mixed surfaces containing both adsorbed Ru-II and [Os(bpy)(2)(4,4 '-(CO2H)(2)bpy)](PF6)(2) (Os-II), Ru-II*-to-Os-II energy transfer occurs with DeltaG degrees = -0.40 eV. On the basis of CW emission and lifetime measurements, the extent of quenching varies with the fractional surface coverage of Os-II, Fo(s)(II). The average rate constant for energy transfer is exponentially dependent on distance r according to the equation, k(en)(r) = k(en)(r(o)) exp(-beta (en)(r - ro)), consistent with a dominant role for the Dexter (exchange) energy transfer mechanism. In this equation, the rate constant at close contact, r(o), is = 2.7 x 10(7) s(-1) and beta = 0.35 Angstrom (-1). By using emission spectral fitting to evaluate the barrier parameters for energy transfer, the energy transfer matrix element at close contact is = 0.4 cm(-1). As shown by CW emission measurements, the extent of Ru-II* quenching is also dependent on the fractional coverage of Ru-II but in a complex way. A qualitative model is proposed to explain the data based on (1) Ru-II* - Os-II energy transfer, (2) cross-surface energy migration by a random walk and (3) Ru-II* - Os energy transfer following Ru-II* - Ru-II migration by percolation. C1 Univ N Carolina, Dept Chem, Chapel Hill, NC 27599 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Meyer, TJ (reprint author), Univ N Carolina, Dept Chem, CB 3290, Chapel Hill, NC 27599 USA. NR 36 TC 22 Z9 22 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 20 PY 2001 VL 105 IS 37 BP 8895 EP 8904 DI 10.1021/jp0116353 PG 10 WC Chemistry, Physical SC Chemistry GA 473GR UT WOS:000171032600034 ER PT J AU Gerrish, P AF Gerrish, P TI The rhythm of microbial adaptation SO NATURE LA English DT Article ID NATURAL-SELECTION; EVOLUTION; POPULATION; RECOMBINATION; INTERFERENCE; LIMITS AB The evolutionary biologist "studies the steps by which the miraculous adaptations so characteristic of every aspect of the organic world have evolved''(1). But the general nature of such adaptive steps is still unclear. Evolution is often thought to be random and dependent on unpredictable events(2). In this light, one might expect the steps taken by adaptation to be completely random, both biologically and temporally. Here I present a mathematical derivation to show that, on the contrary, adaptive steps can have fairly strong rhythm. I find that the strength of the adaptive rhythm, that is its relative temporal regularity, is equal to a constant that is the same for all microbial populations. As a consequence, numbers of accumulated adaptations are predicted to have a universal variance/mean ratio. The theory derived here is potentially applicable to the study of molecular evolution. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Gerrish, P (reprint author), Los Alamos Natl Lab, T-10,Mailstop K710, Los Alamos, NM 87545 USA. OI Gerrish, Philip/0000-0001-6393-0553 NR 29 TC 50 Z9 51 U1 0 U2 2 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 20 PY 2001 VL 413 IS 6853 BP 299 EP 302 DI 10.1038/35095046 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 473KB UT WOS:000171040500037 PM 11565030 ER PT J AU Andersen, E Blaes, R Brom, JM Cherney, M de la Cruz, B Fernandez, C Garabatos, C Garzon, JA Geist, WM Greiner, DE Gruhn, CR Hafidouni, M Hrubec, J Jones, PG Judd, EG Kuipers, JPM Ladrem, M de Guevara, PL Lovhoiden, G MacNaughton, J Mosquera, J Natkaniec, Z Nelson, JM Neuhofer, G de los Heros, CP Plo, M Porth, P Powell, B Ramil, A Rohringer, H Sakrejda, I Thorsteinsen, TF Traxler, J Voltolini, C Wozniak, K Yanez, A Zybert, R AF Andersen, E Blaes, R Brom, JM Cherney, M de la Cruz, B Fernandez, C Garabatos, C Garzon, JA Geist, WM Greiner, DE Gruhn, CR Hafidouni, M Hrubec, J Jones, PG Judd, EG Kuipers, JPM Ladrem, M de Guevara, PL Lovhoiden, G MacNaughton, J Mosquera, J Natkaniec, Z Nelson, JM Neuhofer, G de los Heros, CP Plo, M Porth, P Powell, B Ramil, A Rohringer, H Sakrejda, I Thorsteinsen, TF Traxler, J Voltolini, C Wozniak, K Yanez, A Zybert, R TI Measurement of negative particle multiplicity in S-Pb collisions at 200 GeV/c per nucleon with the NA36 TPC SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION INTERACTIONS; CROSS-SECTIONS; MULTIPARTICLE PRODUCTION; ENTROPY; S-32; DISTRIBUTIONS; ENERGY AB A high statistics Study of the negative particle multiplicity distribution from S-Pb collisions at 200 GeV/c per nucleon is presented. The NA36 TPC was used to detect charged particles; corrections are based upon the maximum entropy method. (C) 2001 Published by Elsevier Science B.V. C1 Univ Bergen, Dept Phys, N-5007 Bergen, Norway. Univ Strasbourg 1, CNRS, IN2P3, IReS, F-67037 Strasbourg 2, France. Creighton Univ, Dept Phys, Omaha, NE 68178 USA. CIEMAT, Div Fis Particulas, E-28040 Madrid, Spain. Univ Santiago, Dept Fis Particulas, E-15706 Santiago De Compostela, Spain. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Austrian Acad Sci, Inst Hochenergiephys, HEPHY, A-1050 Vienna, Austria. Univ Birmingham, Sch Phys & Space Res, Birmingham B15 2TT, W Midlands, England. CERN, European Org Nucl Res, CH-1211 Geneva 23, Switzerland. Inst Fiz Jadrowej, PL-30005 Krakow 30, Poland. RP Andersen, E (reprint author), Haukeland Hosp, Med Tek Avd, N-5021 Bergen, Norway. RI de la Cruz, Begona/K-7552-2014; Yanez, Armando/L-2957-2014; Plo Casasus, Maximo/M-1445-2014; Ramil, Alberto/B-4698-2008; OI Yanez, Armando/0000-0003-4626-7993; Plo Casasus, Maximo/0000-0002-2289-918X; Ramil, Alberto/0000-0002-5333-9425; Perez de los Heros, Carlos/0000-0002-2084-5866 NR 37 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD SEP 20 PY 2001 VL 516 IS 3-4 BP 249 EP 256 DI 10.1016/S0370-2693(01)00853-X PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 474TB UT WOS:000171122000003 ER PT J AU Adams, GS Adams, T Bar-Yam, Z Bishop, JM Bodyagin, VA Brown, DS Cason, NM Chung, SU Cummings, JP Danyo, K Demianov, AI Denisov, S Dorofeev, V Dowd, JP Eugenio, P Fan, XL Gribushin, AM Hackenburg, RW Hayek, M Hu, J Ivanov, EI Joffe, D Kachaev, I Kern, W King, E Kodolova, OL Korotkikh, VL Kostin, MA Kuhn, J Lipaev, V Losecco, JM Lu, M Manak, JJ Napolitano, J Nozar, M Olchanski, C Ostrovidov, AI Pedlar, TK Popov, A Ryabchikov, D Sanjari, AH Sarycheva, LI Seth, KK Shenhav, N Shen, X Shephard, WD Sinev, NB Stienike, DL Taegar, SA Thompson, DR Tomaradze, A Vardanyan, IN Weygand, DP White, D Willutzki, HJ Yershov, AA AF Adams, GS Adams, T Bar-Yam, Z Bishop, JM Bodyagin, VA Brown, DS Cason, NM Chung, SU Cummings, JP Danyo, K Demianov, AI Denisov, S Dorofeev, V Dowd, JP Eugenio, P Fan, XL Gribushin, AM Hackenburg, RW Hayek, M Hu, J Ivanov, EI Joffe, D Kachaev, I Kern, W King, E Kodolova, OL Korotkikh, VL Kostin, MA Kuhn, J Lipaev, V Losecco, JM Lu, M Manak, JJ Napolitano, J Nozar, M Olchanski, C Ostrovidov, AI Pedlar, TK Popov, A Ryabchikov, D Sanjari, AH Sarycheva, LI Seth, KK Shenhav, N Shen, X Shephard, WD Sinev, NB Stienike, DL Taegar, SA Thompson, DR Tomaradze, A Vardanyan, IN Weygand, DP White, D Willutzki, HJ Yershov, AA TI Observation of pseudoscalar and axial vector resonances in pi(-) p -> K+K-pi(0)n at 18 GeV SO PHYSICS LETTERS B LA English DT Article ID PARTIAL-WAVE ANALYSIS; SPIN-PARITY ANALYSIS; ETA-PI+PI SYSTEM; P INTERACTIONS; DRIFT CHAMBER; MESON; REST; K(K)OVER-BAR-PI; ANNIHILATION; DECAYS AB The number of pseudoscalar mesons in the mass range from 1400 to 1500 MeV/c(2) has been a subject of considerable interest for many years, with several experiments having presented evidence for two closely spaced states. A new measurement of the reaction pi (-)p --> K(+)K(-)pi (0)n has been made at a beam energy of 18 GeV. A partial wave analysis of the K(+)K(-)pi (0) system shows evidence for three pseudoscalar resonances, eta (1295), eta (1416), and eta (1485), as well as two axial vectors, f(1)(1285), and f(1)(1420). Their observed masses, widths and decay properties are reported. No signal was observed for C(1480), an I-G J(PC) = 1(+)1(--) state previously reported in phi pi (0) decay. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Rensselaer Polytech Inst, Dept Phys, Troy, NY 12180 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Univ Massachusetts, Dept Phys, N Dartmouth, MA 02747 USA. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow 119899, Russia. Northwestern Univ, Dept Phys, Evanston, IL 60208 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Protvino High Energy Phys Inst, Protvino 142284, Russia. Thomas Jefferson Natl Accelerator Facil, Dept Phys, Newport News, VA 23606 USA. RAFAEL, IL-31021 Haifa, Israel. Inst High Energy Phys, Beijing 100039, Peoples R China. RP Rensselaer Polytech Inst, Dept Phys, Troy, NY 12180 USA. EM adamsg@rpi.edu RI Demianov, Andrei/E-4565-2012; Vardanyan, Irina/K-7981-2012; Gribushin, Andrei/J-4225-2012 NR 49 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD SEP 20 PY 2001 VL 516 IS 3-4 BP 264 EP 272 DI 10.1016/S0370-2693(01)00951-0 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 474TB UT WOS:000171122000005 ER PT J AU Chekanov, S Derrick, M Krakauer, D Magill, S Musgrave, B Pellegrino, A Repond, J Yoshida, R Mattingly, MCK Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Sartorelli, G Zichichi, A Aghuzumtsyan, G Brock, I Goers, S Hartmann, H Hilger, E Irrgang, P Jakob, HP Kappes, A Katz, UF Kerger, R Kind, O Paul, E Rautenberg, J Schnurbusch, H Stifutkin, A Tandler, J Voss, KC Weber, A Wieber, H Bailey, DS Brook, NH Cole, JE Foster, B Heath, GP Heath, HF Robins, S Ridrigues, E Scott, J Tapper, RJ Wing, M Capua, M Mastroberardino, A Schioppa, M Susinno, G Jeoung, HY Kim, JY Lee, JH Lim, IT Ma, KJ Pac, MY Caldwell, A Helbich, M Liu, W Liu, X Mellado, B Paganis, S Sampson, S Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Klimek, K Olkiewicz, K Przybycien, MB Stopa, P Zawiejski, L Bednarek, B Jelen, K Kisielewska, D Kowal, AM Kowal, M Kowalski, T Mindur, B Przybycien, M Rulikowska-Zarebska, E Suszycki, L Szuba, D Bauerdick, LAT Behrens, U Borras, K Chiochia, V Crittenden, J Dannheim, D Desler, K Drews, G Fox-Murphy, A Fricke, U Geiser, A Goebel, F Gottlicher, P Graciani, R Haas, T Hain, W Hartner, GF Hebbel, K Hillert, S Koch, W Kotz, U Kowalski, H Labes, H Lohr, B Mankel, R Martens, J Martinez, M Milite, M Moritz, M Notz, D Petrucci, MC Polini, A Schneekloth, U Selonke, F Stonjek, S Wolf, G Wollmer, U Whitmore, JJ Wichmann, R Youngman, C Zeuner, W Coldewey, C Viani, ALD Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, PG Bamberger, A Benen, A Coppola, N Markun, P Raach, H Wolfle, S Bell, M Bussey, PJ Doyle, AT Glasman, C Lee, SW Lupi, A McCance, GJ Saxon, DH Skillicorn, IO Bodmann, B Gendner, N Holm, U Salehi, H Wick, K Yildirim, A Ziegler, A Carli, T Garfagnini, A Gialas, I Lohrmann, E Foudas, C Goncalo, R Long, KR Metlica, F Miller, DB Tapper, AD Walker, R Cloth, P Filges, D Kuze, M Nagano, K Tokushuku, K Yamada, S Yamazaki, Y Barakbaev, AN Boos, EG Pokrovskiy, NS Zhautykov, BO Ahn, SH Lee, SB Park, SK Lim, H Son, D Barreiro, F Garcia, G Gonzalez, O Labarga, L del Peso, J Redondo, I Terron, J Vazquez, M Barbi, M Bertolin, A Corriveau, F Ochs, A Padhi, S Stairs, DG Tsurugai, T Antonov, A Bashkirov, V Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V Suchkov, S Dementiev, RK Ermolov, PF Golubkov, YA Katkov, II Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Levchenko, BB Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Vlasov, NN Zotkin, SA Bokel, C Engelen, J Grijpink, S Maddox, E Koffeman, E Kooijman, P Schagen, S Tassi, E Tiecke, H Tuning, N Velthuis, JJ Wiggers, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Gilmore, J Ginsberg, CM Kim, CL Ling, TY Boogert, S Cooper-Sarkar, AM Devenish, RCE Ferrando, J Grosse-Knetter, J Matsushita, T Rigby, M Ruske, O Sutton, MR Walczak, R Brugnera, R Carlin, R Dal Corso, F Dusini, S Limentani, S Longhin, A Parenti, A Posocco, M Stanco, L Turcato, M Adamczyk, L Iannotti, L Oh, BY Saull, PRB Toothacker, WS Iga, Y D'Agostini, G Marini, G Nigro, A Cormack, C Hart, JC McCubbin, NA Epperson, D Heusch, C Sadrozinski, HFW Seiden, A Williams, DC Park, IH Pavel, N Abramowicz, H Dagan, S Gabareen, A Kananov, S Kreisel, A Levy, A Abe, T Fusayasu, T Kohno, T Umemori, K Yamashita, T Hamatsu, R Hirose, T Inuzuka, M Kitamura, S Matsuzawa, K Nishimura, T Arneodo, M Cartiglia, N Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Ruspa, M Sacchi, R Solano, A Staiano, A Bailey, DC Fagerstroem, CP Galea, R Koop, T Levman, GM Martin, JF Mirea, A Sabetfakhri, A Butterworth, JM Gwenlan, C Hall-Wilton, R Hayes, ME Heaphy, EA Jones, TW Lane, JB Lightwood, MS West, BJ Ciborowski, J Ciesielski, R Grzelak, G Nowak, RJ Pawlak, JM Smalska, B Tymieniecka, T Ukleja, J Zakrzewski, JA Zarnecki, AF Adamus, M Plucinski, P Sztuk, J Deppe, O Eisenberg, Y Gladilin, LK Hochman, D Karshon, U Breitweg, J Chapin, D Cross, R Kcira, D Lammers, S Reeder, DD Savin, AA Smith, WH Deshpande, A Dhawan, S Hughes, VW Straub, PB Bhadra, S Catterall, CD Frisken, WR Khakzad, M Menary, S AF Chekanov, S Derrick, M Krakauer, D Magill, S Musgrave, B Pellegrino, A Repond, J Yoshida, R Mattingly, MCK Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Cifarelli, L Cindolo, F Contin, A Corradi, M De Pasquale, S Giusti, P Iacobucci, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Sartorelli, G Zichichi, A Aghuzumtsyan, G Brock, I Goers, S Hartmann, H Hilger, E Irrgang, P Jakob, HP Kappes, A Katz, UF Kerger, R Kind, O Paul, E Rautenberg, J Schnurbusch, H Stifutkin, A Tandler, J Voss, KC Weber, A Wieber, H Bailey, DS Brook, NH Cole, JE Foster, B Heath, GP Heath, HF Robins, S Ridrigues, E Scott, J Tapper, RJ Wing, M Capua, M Mastroberardino, A Schioppa, M Susinno, G Jeoung, HY Kim, JY Lee, JH Lim, IT Ma, KJ Pac, MY Caldwell, A Helbich, M Liu, W Liu, X Mellado, B Paganis, S Sampson, S Schmidke, WB Sciulli, F Chwastowski, J Eskreys, A Figiel, J Klimek, K Olkiewicz, K Przybycien, MB Stopa, P Zawiejski, L Bednarek, B Jelen, K Kisielewska, D Kowal, AM Kowal, M Kowalski, T Mindur, B Przybycien, M Rulikowska-Zarebska, E Suszycki, L Szuba, D Bauerdick, LAT Behrens, U Borras, K Chiochia, V Crittenden, J Dannheim, D Desler, K Drews, G Fox-Murphy, A Fricke, U Geiser, A Goebel, F Gottlicher, P Graciani, R Haas, T Hain, W Hartner, GF Hebbel, K Hillert, S Koch, W Kotz, U Kowalski, H Labes, H Lohr, B Mankel, R Martens, J Martinez, M Milite, M Moritz, M Notz, D Petrucci, MC Polini, A Schneekloth, U Selonke, F Stonjek, S Wolf, G Wollmer, U Whitmore, JJ Wichmann, R Youngman, C Zeuner, W Coldewey, C Viani, ALD Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, PG Bamberger, A Benen, A Coppola, N Markun, P Raach, H Wolfle, S Bell, M Bussey, PJ Doyle, AT Glasman, C Lee, SW Lupi, A McCance, GJ Saxon, DH Skillicorn, IO Bodmann, B Gendner, N Holm, U Salehi, H Wick, K Yildirim, A Ziegler, A Carli, T Garfagnini, A Gialas, I Lohrmann, E Foudas, C Goncalo, R Long, KR Metlica, F Miller, DB Tapper, AD Walker, R Cloth, P Filges, D Kuze, M Nagano, K Tokushuku, K Yamada, S Yamazaki, Y Barakbaev, AN Boos, EG Pokrovskiy, NS Zhautykov, BO Ahn, SH Lee, SB Park, SK Lim, H Son, D Barreiro, F Garcia, G Gonzalez, O Labarga, L del Peso, J Redondo, I Terron, J Vazquez, M Barbi, M Bertolin, A Corriveau, F Ochs, A Padhi, S Stairs, DG Tsurugai, T Antonov, A Bashkirov, V Danilov, P Dolgoshein, BA Gladkov, D Sosnovtsev, V Suchkov, S Dementiev, RK Ermolov, PF Golubkov, YA Katkov, II Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Levchenko, BB Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Vlasov, NN Zotkin, SA Bokel, C Engelen, J Grijpink, S Maddox, E Koffeman, E Kooijman, P Schagen, S Tassi, E Tiecke, H Tuning, N Velthuis, JJ Wiggers, L de Wolf, E Brummer, N Bylsma, B Durkin, LS Gilmore, J Ginsberg, CM Kim, CL Ling, TY Boogert, S Cooper-Sarkar, AM Devenish, RCE Ferrando, J Grosse-Knetter, J Matsushita, T Rigby, M Ruske, O Sutton, MR Walczak, R Brugnera, R Carlin, R Dal Corso, F Dusini, S Limentani, S Longhin, A Parenti, A Posocco, M Stanco, L Turcato, M Adamczyk, L Iannotti, L Oh, BY Saull, PRB Toothacker, WS Iga, Y D'Agostini, G Marini, G Nigro, A Cormack, C Hart, JC McCubbin, NA Epperson, D Heusch, C Sadrozinski, HFW Seiden, A Williams, DC Park, IH Pavel, N Abramowicz, H Dagan, S Gabareen, A Kananov, S Kreisel, A Levy, A Abe, T Fusayasu, T Kohno, T Umemori, K Yamashita, T Hamatsu, R Hirose, T Inuzuka, M Kitamura, S Matsuzawa, K Nishimura, T Arneodo, M Cartiglia, N Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Ruspa, M Sacchi, R Solano, A Staiano, A Bailey, DC Fagerstroem, CP Galea, R Koop, T Levman, GM Martin, JF Mirea, A Sabetfakhri, A Butterworth, JM Gwenlan, C Hall-Wilton, R Hayes, ME Heaphy, EA Jones, TW Lane, JB Lightwood, MS West, BJ Ciborowski, J Ciesielski, R Grzelak, G Nowak, RJ Pawlak, JM Smalska, B Tymieniecka, T Ukleja, J Zakrzewski, JA Zarnecki, AF Adamus, M Plucinski, P Sztuk, J Deppe, O Eisenberg, Y Gladilin, LK Hochman, D Karshon, U Breitweg, J Chapin, D Cross, R Kcira, D Lammers, S Reeder, DD Savin, AA Smith, WH Deshpande, A Dhawan, S Hughes, VW Straub, PB Bhadra, S Catterall, CD Frisken, WR Khakzad, M Menary, S TI Three-jet production in diffractive deep inelastic scattering at HERA SO PHYSICS LETTERS B LA English DT Article ID LARGE-RAPIDITY-GAP; MONTE-CARLO GENERATOR; CENTRAL TRACKING DETECTOR; ZEUS BARREL CALORIMETER; COLOR DIPOLE MODEL; CROSS-SECTIONS; E+E-ANNIHILATION; QCD CASCADES; FINAL-STATE; EVENTS AB Three-jet production in the reaction ep --> eXp has been studied with the ZEUS detector at HERA using an integrated luminosity of 42.74 pb(-1).The data were measured in the kinematic region 5 < Q(2) < 100 GeV2, 200 < W < 250 GeV and 23 < M-X < 40 GeV. The diffractive signal was selected by requiring a large rapidity gap in the outgoing proton direction. Jets were reconstructed in the centre-of-mass system of X using the exclusive k(T)-algorithm. A sample of three-jet events in diffraction has been identified. Differential cross sections were measured as a function of the jet pseudorapidity and jet transverse momentum with respect to the virtual photon-pomeron axis. The jets going in the pomeron direction are broader than those going in the virtual-photon direction. This is consistent with models predicting that gluons a-re predominantly produced in the pomeron direction and quarks in the virtual-photon direction. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Tokyo, Tokyo, Japan. Univ Piemonte Orientale, I-28100 Novara, Italy. Univ Lodz, PL-90131 Lodz, Poland. Argonne Natl Lab, Argonne, IL 60439 USA. Andrews Univ, Berrien Springs, MI 49104 USA. Univ Bologna, Bologna, Italy. Ist Nazl Fis Nucl, Bologna, Italy. Univ Bonn, Inst Phys, D-5300 Bonn, Germany. Univ Bristol, HH Wills Phys Lab, Bristol BS8 1TL, Avon, England. Univ Calabria, Dept Phys, I-87036 Cosenza, Italy. Ist Nazl Fis Nucl, Cosenza, Italy. Chonnam Natl Univ, Kwangju, South Korea. Columbia Univ, Nevis Labs, Irvington, NY USA. Inst Nucl Phys, Krakow, Poland. Acad Min & Met, Fac Phys & Nucl Techniques, Krakow, Poland. Jagiellonian Univ, Dept Phys, Krakow, Poland. DESY, D-2000 Hamburg, Germany. DESY, Zeuthen, Germany. Univ Florence, Florence, Italy. Ist Nazl Fis Nucl, Florence, Italy. Univ Freiburg, Fak Phys, Freiburg, Germany. Univ Glasgow, Dept Phys & Astron, Glasgow, Lanark, Scotland. Univ Hamburg, Inst Expt Phys 1, Hamburg, Germany. Univ Hamburg, Inst Expt Phys 2, D-2000 Hamburg, Germany. Univ London Imperial Coll Sci Technol & Med, High Energy Nucl Phys Grp, London, England. Forschungszentrum Julich, Inst Kernphys, D-5170 Julich, Germany. KEK, Inst Particle & Nucl Studies, Tsukuba, Ibaraki, Japan. Minist Educ & Sci Kazakhstan, Inst Phys & Technol, Alma Ata, Kazakhstan. Korea Univ, Seoul 136701, South Korea. Kyungpook Natl Univ, Taegu 702701, South Korea. Univ Autonoma Madrid, Dept Fis Teor, Madrid, Spain. McGill Univ, Dept Phys, Montreal, PQ, Canada. Meiji Gakuin Univ, Fac Gen Educ, Yokohama, Kanagawa, Japan. Moscow Phys Engn Inst, Moscow, Russia. Moscow MV Lomonosov State Univ, Inst Nucl Phys, Moscow, Russia. NIKHEF H, NL-1009 DB Amsterdam, Netherlands. Univ Amsterdam, Amsterdam, Netherlands. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Oxford, Dept Phys, Oxford, England. Univ Padua, Dipartimento Fis, Padua, Italy. Ist Nazl Fis Nucl, Padua, Italy. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Polytech Univ, Sagamihara, Kanagawa, Japan. Univ Roma La Sapienza, Dipartimento Fis, I-00185 Rome, Italy. Ist Nazl Fis Nucl, Rome, Italy. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Seoul Natl Univ, Seoul, South Korea. Univ Siegen, Fachbereich Phys, D-5900 Siegen, Germany. Tel Aviv Univ, Sch Phys, Raymond & Beverly Sackler Fac Exact Sci, IL-69978 Tel Aviv, Israel. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Tokyo Metropolitan Univ, Dept Phys, Tokyo, Japan. Univ Turin, Dipartimento Fis Sperimentale, Turin, Italy. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Toronto, Dept Phys, Toronto, ON, Canada. UCL, Dept Phys & Astron, London, England. Warsaw Univ, Inst Expt Phys, Warsaw, Poland. Inst Nucl Studies, PL-00681 Warsaw, Poland. Weizmann Inst Sci, Dept Particle Phys, IL-76100 Rehovot, Israel. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Yale Univ, Dept Phys, New Haven, CT USA. York Univ, Dept Phys, Toronto, ON M3J 2R7, Canada. RP Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. EM b.foster@bris.ac.uk RI De Pasquale, Salvatore/B-9165-2008; Wiggers, Leo/B-5218-2015; Tassi, Enrico/K-3958-2015; Wing, Matthew/C-2169-2008; Bashkirov, Vladimir/A-4818-2008; Doyle, Anthony/C-5889-2009; Ferrando, James/A-9192-2012; Golubkov, Yury/E-1643-2012; Levchenko, B./D-9752-2012; Proskuryakov, Alexander/J-6166-2012; Dementiev, Roman/K-7201-2012; Katz, Uli/E-1925-2013; Gladilin, Leonid/B-5226-2011; Solomin, Anatoly/C-3072-2016; dusini, stefano/J-3686-2012; Goncalo, Ricardo/M-3153-2016; Capua, Marcella/A-8549-2015; OI De Pasquale, Salvatore/0000-0001-9236-0748; Wiggers, Leo/0000-0003-1060-0520; Doyle, Anthony/0000-0001-6322-6195; Ferrando, James/0000-0002-1007-7816; Katz, Uli/0000-0002-7063-4418; Gladilin, Leonid/0000-0001-9422-8636; dusini, stefano/0000-0002-1128-0664; Goncalo, Ricardo/0000-0002-3826-3442; Capua, Marcella/0000-0002-2443-6525; PAGANIS, STATHES/0000-0002-1950-8993 NR 69 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD SEP 20 PY 2001 VL 516 IS 3-4 BP 273 EP 292 DI 10.1016/S0370-2693(01)00928-5 PG 20 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 474TB UT WOS:000171122000006 ER PT J AU Song, Z Pascual, JI Conrad, H Horn, K Rust, HP AF Song, Z Pascual, JI Conrad, H Horn, K Rust, HP TI Surface states of d character imaged by scanning tunneling microscopy SO SURFACE SCIENCE LA English DT Article DE scanning tunneling microscopy; scanning tunneling spectroscopies; surface structure, morphology, roughness; and topography; surface electronic phenomena (work function; surface potential, surface states, etc.); alloys; single crystal surfaces ID 2-DIMENSIONAL ELECTRON-GAS; FRIEDEL OSCILLATIONS; NIAL(110); WAVES; SPECTROSCOPY; LIFETIME; DENSITY; STEPS; STM AB The electronic structure of NiAl(1 1 0) is measured with scanning tunneling spectroscopy at a temperature of 4 K. Reciprocal space images of surface states are obtained by Fourier transformation (FT) of wave patterns created by defects in differential conductance images. Each surface state exhibits a different wave vector pattern in 2-dimensional k-space. Surface states with strong s-p character exhibit contours distributed uniformly in all directions over most of their energy range, while states with d character exhibit strongly directional patterns. For these states, the dispersion is measured and compare favorably with results from photoemission experiments and with theoretical calculations. An indication of a strong interaction between sp- and d-surface states was found from both the Fourier transformed conductance images and their dispersion behaviors. We put forward some arguments to assign one of the FT image features to the sigma(2) (d(xy) character) surface state, which is dipole forbidden in photoemission. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Max Planck Gesell, Fritz Haber Inst, D-14195 Berlin, Germany. RP Song, Z (reprint author), Brookhaven Natl Lab, Dept Chem, Bldg 555,POB 5000, Upton, NY 11973 USA. EM songz@bnl.gov; pascual@fhi-berlin.mpg.de RI Pascual, Jose/F-3489-2011; Pascual, Jose Ignacio/N-3102-2016 OI Pascual, Jose Ignacio/0000-0002-7152-4747 NR 21 TC 9 Z9 9 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 20 PY 2001 VL 491 IS 1-2 BP 39 EP 47 DI 10.1016/S0039-6028(01)01434-0 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 479EA UT WOS:000171389900008 ER PT J AU Soong, Y Link, TA Schoffstall, MR Gray, ML Fauth, DJ Knoer, JP Jones, JR AF Soong, Y Link, TA Schoffstall, MR Gray, ML Fauth, DJ Knoer, JP Jones, JR TI Dry beneficiation of Slovakian coal SO FUEL PROCESSING TECHNOLOGY LA English DT Article DE beneficiation; triboelectrostatics; Slovakian coal AB The dry beneficiation of three types of Slovakian brown coal, namely Ci'gel, Handlova', and Nova'ky coal was conducted via triboelectrostatic separation. Three different types of separators -parallel plate, cylindrical and louvered plate-were used for this study. It was found that a parallel plate separator could reduce the ash contents of Ci'gel and Handlova' coals. The poor quality of separation for the Nova'ky coal studied is probably due to the particle-particle interactions and surface oxidation states of the coal. Published by Elsevier Science B.V. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP Soong, Y (reprint author), US DOE, Natl Energy Technol Lab, POB 10940, Pittsburgh, PA 15236 USA. NR 15 TC 13 Z9 14 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-3820 J9 FUEL PROCESS TECHNOL JI Fuel Process. Technol. PD SEP 19 PY 2001 VL 72 IS 3 BP 185 EP 198 DI 10.1016/S0378-3820(01)00187-4 PG 14 WC Chemistry, Applied; Energy & Fuels; Engineering, Chemical SC Chemistry; Energy & Fuels; Engineering GA 466JF UT WOS:000170641900002 ER PT J AU Huynh, MHV White, PS Meyer, TJ AF Huynh, MHV White, PS Meyer, TJ TI Formation and O-atom reactivity of the Os(IV)-sulfilimido and Os(IV)-sulfoximido complexes, cis-/trans-[OSIV(tpy)(Cl)(2)(NSC6H3Me2)] and cis-/trans-[Os-IV(tpy)(Cl)(2)(NS(O)C6H3Me2)] SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TRANSITION-METAL COMPLEXES; HYDRAZIDO COMPLEXES; CRYSTAL-STRUCTURE; OSMIUM HYDRAZIDO; CHEMISTRY; OXIDATION; EPOXIDATION; MECHANISM; HALIDES; SERIES C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Univ N Carolina, Dept Chem, Venable & Kenan Labs, Chapel Hill, NC 27599 USA. RP Huynh, MHV (reprint author), Los Alamos Natl Lab, Div Chem, MS J515, Los Alamos, NM 87545 USA. NR 39 TC 25 Z9 25 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 19 PY 2001 VL 123 IS 37 BP 9170 EP 9171 DI 10.1021/ja002874r PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 471YM UT WOS:000170956300036 PM 11552829 ER PT J AU Lu, HP Iakoucheva, LM Ackerman, EJ AF Lu, HP Iakoucheva, LM Ackerman, EJ TI Single-molecule conformational dynamics of fluctuating noncovalent DNA - Protein interactions a in DNA damage recognition SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID FLUORESCENCE SPECTROSCOPY; ENZYMATIC DYNAMICS; ELECTRON-TRANSFER; FORCE MICROSCOPE; ROOM-TEMPERATURE; MECHANISM; REPAIR; DEPENDENCE; MISMATCH; ENZYMES C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Pacific NW Natl Lab, Mol Biosci Dept, Richland, WA 99352 USA. RP Lu, HP (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 35 TC 38 Z9 40 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 19 PY 2001 VL 123 IS 37 BP 9184 EP 9185 DI 10.1021/ja0058942 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 471YM UT WOS:000170956300043 PM 11552836 ER PT J AU Zhang, ZT Dai, S AF Zhang, ZT Dai, S TI Preparation and characterization of novel inorganic-organic mesoscopic ordered composites with bridges formed by coordination compounds SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MESOPOROUS MOLECULAR-SIEVES; MESOPHASES; FRAMEWORKS; CHEMISTRY; SILICATES C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Dai, S (reprint author), Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RI Dai, Sheng/K-8411-2015 OI Dai, Sheng/0000-0002-8046-3931 NR 25 TC 17 Z9 18 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 19 PY 2001 VL 123 IS 37 BP 9204 EP 9205 DI 10.1021/ja0158556 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 471YM UT WOS:000170956300053 PM 11552846 ER PT J AU Shafir, A Arnold, J AF Shafir, A Arnold, J TI Stabilization of a cationic Ti center by a ferrocene moiety: A remarkably short Ti-Fe interaction in the diamide {[(eta(5)-C5H4NSiMe3)(2)Fe]TiCl2}(2)(2+) SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ETHYLENE POLYMERIZATION; LIVING POLYMERIZATION; METAL-COMPLEXES; LIGAND; REACTIVITY; ZIRCONIUM; TITANIUM; BOND; METALLOCENE; DERIVATIVES C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Arnold, J (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Shafir, Alexandr/D-1676-2009; Arnold, John/F-3963-2012 OI Shafir, Alexandr/0000-0002-8127-2299; Arnold, John/0000-0001-9671-227X NR 32 TC 67 Z9 68 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 19 PY 2001 VL 123 IS 37 BP 9212 EP 9213 DI 10.1021/ja0161857 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 471YM UT WOS:000170956300057 PM 11552850 ER PT J AU d'Erme, M Yang, GL Sheagly, E Palitti, F Bustamante, C AF d'Erme, M Yang, GL Sheagly, E Palitti, F Bustamante, C TI Effect of poly(ADP-ribosyl)ation and Mg2+ ions on chromatin structure revealed by scanning force microscopy SO BIOCHEMISTRY LA English DT Article ID RAT TESTIS CHROMATIN; NUCLEOSOME STRUCTURE; ADP-RIBOSYLATION; DNA; POLYMERASE; HISTONE-H1; PROTEINS; INVITRO; REPAIR; CARCINOGENESIS AB Poly(ADP-ribosyl)ation of nuclear proteins is responsible for major changes in the high-order chromatin structure. The effects of this post-translation modification on nuclear architecture were examined at different Mg2+ concentrations using scanning force microscopy. A quantitative analysis of the internucleosomal distance, the width, and the volume of chromatin fibers imaged in tapping mode reveals that poly(ADP-ribosyl)ation induces a complete relaxation and decondensation of the chromatin structure. Our data, on the center-to-center distance between adjacent nucleosomes and on the fiber width, indicate that the poly(ADP-ribosyl)ated fibers remain significantly decondensed even in the presence of Mg2+. Our results also show that the Mg2+ assumes an important role in the folding of chromatin structure, but Mg2+ is not able to restore the native feature of chromatin, when the fibers are depleted of H1/H5 histones. The combined effect of post-translation modification and cation ions on the chromatin structure shows that poly(ADP- ribosyl)ation could promote accessibility to DNA even in those nuclear processes that require Mg2+. C1 Univ Roma La Sapienza, Dept Biochem Sci, I-00185 Rome, Italy. Drexel Univ, Dept Phys, Philadelphia, PA 19104 USA. Univ Oregon, Inst Mol Biol, Eugene, OR 97403 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cell Biol, Berkeley, CA 94720 USA. RP d'Erme, M (reprint author), Univ Roma La Sapienza, Dept Biochem Sci, P A Moro 5, I-00185 Rome, Italy. NR 63 TC 17 Z9 17 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD SEP 18 PY 2001 VL 40 IS 37 BP 10947 EP 10955 DI 10.1021/bi002742 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 473GP UT WOS:000171032400004 PM 11551189 ER PT J AU Yang, BS Lal, J Richetti, P Marques, CM Russel, WB Prud'homme, RK AF Yang, BS Lal, J Richetti, P Marques, CM Russel, WB Prud'homme, RK TI Interaction of hydrophobically modified polymers and surfactant lamellar phase SO LANGMUIR LA English DT Article ID NONIONIC MICROEMULSION; LYOTROPIC PHASES; X-RAY; MICROSTRUCTURE; MEMBRANES; SYSTEM; POLYELECTROLYTE; ASSOCIATION; CONFINEMENT; SCATTERING AB We investigate the effect of polysoaps on the phase behavior and membrane elastic properties of the lyotropic lamellar (L-alpha) phase of the nonionic surfactant penta(ethylene glycol) dodecyl ether (C12E5). The polysoap is a hydrophobically modified polymer (hm-polymer) with n-alkyl side groups randomly grafted to a polyacrylate (PAA) backbone. The membrane properties are extracted from small-angle neutron scattering data based on a model developed by Nallet et al. and the excess area method developed by Roux et al. The phase behavior, membrane rigidity, compression modulus, and bilayer mean bending modulus are found to be independent of molecular weight, polydispersity, and hydrophobe length of hm-polymers. The rigidity and compression moduli of membranes increase with increasing polymer concentration and hydrophobe substitution level. A minimum hydrophobic interaction strength (combination of hydrophobe length and hydrophobe substitution level) is required to produce single phase polysoap/lamellar surfactant systems. A scaling model is proposed that defines the boundaries between homogeneous and biphasic solutions based on two criteria: (1) the surface coverage of chain segments between hydrophobus (i.e. blobs) must be less than the available membrane area and (2) the interlamellar spacing must be larger than the blob size. This simple model captures the essential features of the phase diagrams. C1 Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. CNRS, Complex Fluids Lab, UMR 166, Rhodia, Cranbury, NJ 08512 USA. RP Prud'homme, RK (reprint author), Princeton Univ, Dept Chem Engn, Princeton, NJ 08544 USA. RI Marques, Carlos/B-2322-2010; OI Marques, Carlos/0000-0002-3952-0498; Marques, Carlos/0000-0002-6526-1258 NR 38 TC 33 Z9 34 U1 2 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD SEP 18 PY 2001 VL 17 IS 19 BP 5834 EP 5841 DI 10.1021/la001391y PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 473HF UT WOS:000171034000023 ER PT J AU Ball, M Lucas, CA Markovic, NM Murphy, BM Steadman, P Schmidt, TJ Stamenkovic, V Ross, PN AF Ball, M Lucas, CA Markovic, NM Murphy, BM Steadman, P Schmidt, TJ Stamenkovic, V Ross, PN TI X-ray scattering studies of irreversibly adsorbed bismuth on the Pt(111) electrode surface SO LANGMUIR LA English DT Article ID CARBON-MONOXIDE; UNDERPOTENTIAL DEPOSITION; INFRARED-SPECTROSCOPY; INTERFACE STRUCTURE; ATOMIC-STRUCTURE; REDOX BEHAVIOR; CO ADSORPTION; ELECTROCHEMISTRY; RECONSTRUCTION; HYDROGEN AB The surface electrochemistry of irreversibly adsorbed bismuth (Bi-ir) on the Pt(111) electrode in 0.1 M HClO4 has been studied by in situ surface X-ray scattering to correlate the atomic structure with the voltammetric features. Bi-ir saturates at a coverage of similar to one-third of a monolayer and forms a disordered structure on the Pt(111) surface with some evidence that the Bi-ir is mobile. If the Bi-ir coverage is slightly increased, then there is a reduction in the charge under the reversible peaks in the cyclic voltammetry at a potential of similar to0.68 V (vs Pd/H-2). The charge under the reversible peaks is most likely associated with the adsorption of oxygenated species at platinum sites adjacent to Bi-ir atoms. Saturation of the electrolyte with CO and subsequent potential cycling leads to displacement of Bi-ir from the surface and the appearance of an X-ray diffraction pattern due to a p(2 x 2)-3CO adlayer that has previously been observed on the unmodified Pt(111) electrode. C1 Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Kiel, Inst Expt & Angew Phys, D-24098 Kiel, Germany. ESRF, F-38043 Grenoble, France. RP Lucas, CA (reprint author), Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. RI Schmidt, Thomas/A-2586-2010; OI Schmidt, Thomas/0000-0002-1636-367X; Lucas, Christopher/0000-0001-5743-3868 NR 22 TC 11 Z9 11 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD SEP 18 PY 2001 VL 17 IS 19 BP 5943 EP 5946 DI 10.1021/la010192r PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 473HF UT WOS:000171034000037 ER PT J AU Ahrenkiel, SR Hanna, MC AF Ahrenkiel, SR Hanna, MC TI Anti phase-boundary extension in single-variant CuPt-B ordered Ga0.47In0.53As on InP SO APPLIED PHYSICS LETTERS LA English DT Article ID EPITAXIAL LAYERS; GROWTH-RATE; GAINP; MECHANISM; ALLOYS; (GAIN)P AB We describe the extension (tilt) of antiphase boundaries (APBs) in single-variant, CuPt-B ordered, epitaxial Ga0.47In0.53As films grown by low-pressure metalorganic chemical vapor deposition on (001) InP miscut 6 degrees toward (111)B. The mean extension angles [measured from (001) toward the (111)B ordering plane] range from approximately 90 degrees to 123 degrees, in these samples. We suggest that APBs propagate in step-flow growth mode as advancing step edges traverse the intersections of extant APBs and the vicinal (001) surface. (C) 2001 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ahrenkiel, SR (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 17 TC 2 Z9 2 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 17 PY 2001 VL 79 IS 12 BP 1781 EP 1782 DI 10.1063/1.1403255 PG 2 WC Physics, Applied SC Physics GA 472ZL UT WOS:000171014800013 ER PT J AU Zeng, XH Sukiasyan, A Xi, XX Hu, YF Wertz, E Li, Q Tian, W Sun, HP Pan, XQ Lettieri, J Schlom, DG Brubaker, CO Liu, ZK Li, Q AF Zeng, XH Sukiasyan, A Xi, XX Hu, YF Wertz, E Li, Q Tian, W Sun, HP Pan, XQ Lettieri, J Schlom, DG Brubaker, CO Liu, ZK Li, Q TI Superconducting properties of nanocrystalline MgB2 thin films made by an in situ annealing process SO APPLIED PHYSICS LETTERS LA English DT Article AB We have studied the structural and superconducting properties of MgB2 thin films made by pulsed-laser deposition followed by in situ annealing. The cross-sectional transmission electron microscopy reveals a nanocrystalline mixture of textured MgO and MgB2 with very small grain sizes. A zero-resistance transition temperature (T(c)0) of 34 K and a zero-field critical current density (J(c)) of 1.3x10(6) A/cm(2) were obtained. The irreversibility field was similar to8 T at low temperatures, although severe pinning instability was observed. The result is a step towards making the in situ deposition process a viable technique for MgB2 Josephson junction technologies. (C) 2001 American Institute of Physics. C1 Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. Brookhaven Natl Lab, Div Mat & Chem Sci, Upton, NY 11973 USA. RP Xi, XX (reprint author), Penn State Univ, Dept Phys, 104 Davey Lab, University Pk, PA 16802 USA. RI Schlom, Darrell/J-2412-2013; Liu, Zi-Kui/A-8196-2009 OI Schlom, Darrell/0000-0003-2493-6113; Liu, Zi-Kui/0000-0003-3346-3696 NR 19 TC 69 Z9 78 U1 2 U2 11 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 17 PY 2001 VL 79 IS 12 BP 1840 EP 1842 DI 10.1063/1.1405431 PG 3 WC Physics, Applied SC Physics GA 472ZL UT WOS:000171014800033 ER PT J AU Chisolm, ED Wallace, DC AF Chisolm, ED Wallace, DC TI Dynamics of monatomic liquids SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Review ID SHORT-TIME DYNAMICS; SELF-DIFFUSION; SUPERCOOLED LIQUIDS; STATE DYNAMICS; TRANSITION; FILMS; ELEMENTS; GLASSES; FLUIDS; NICKEL AB We present a theory of the dynamics of monatomic liquids built on two basic ideas: (1) the potential surface of the liquid contains three classes of intersecting nearly harmonic valleys, one of which (the 'random' class) dominates the potential surface and consists of valleys which all have the same depth and normal-mode spectrum; and (2) the motion of particles in the liquid can be decomposed into oscillations in a single many-body valley, and nearly instantaneous inter-valley transitions called transits. We review the thermodynamic data which led to the theory, and we discuss the results of molecular dynamics (MD) simulations of sodium and Lennard-Jones argon which support the theory in more detail. Then we apply the theory to problems in equilibrium and nonequilibrium statistical mechanics, and we compare the results to experimental data and M simulations. We also discuss our work in comparison with the quenched normal-mode and instantaneous normal-mode research programmes and suggest directions for future research. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Chisolm, ED (reprint author), Los Alamos Natl Lab, T-1,Mail Stop B221, Los Alamos, NM 87545 USA. NR 46 TC 23 Z9 24 U1 1 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD SEP 17 PY 2001 VL 13 IS 37 BP R739 EP R769 DI 10.1088/0953-8984/13/37/201 PG 31 WC Physics, Condensed Matter SC Physics GA 481VF UT WOS:000171540600001 ER PT J AU Del Duca, V Kilgore, W Oleari, C Schmidt, C Zeppenfeld, D AF Del Duca, V Kilgore, W Oleari, C Schmidt, C Zeppenfeld, D TI Production of a Higgs boson accompanied by two jets via gluon fusion SO PHYSICAL REVIEW LETTERS LA English DT Article ID ONE-LOOP INTEGRALS; CERN LHC AB Real-emission corrections to gg --> H, which lead to H + 2 jet events, are calculated at order alpha (4)(s). Contributions include top-quark triangles, boxes, and pentagon diagrams and are evaluated analytically for arbitrary top mass m(t). This new source of H + 2 jet events is compared to the weak-boson fusion cross section for a range of Higgs boson masses. The heavy top-mass approximation appears to work well for intermediate Higgs-boson masses, provided that the transverse momenta of the final-state partons are smaller than the top-quark mass. C1 Ist Nazl Fis Nucl, Sez Torino, I-10125 Turin, Italy. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Michigan State Univ, Dept Phys & Astron, E Lansing, MI 48824 USA. RP Del Duca, V (reprint author), Ist Nazl Fis Nucl, Sez Torino, Via P Giuria, I-10125 Turin, Italy. RI del duca, vittorio/F-6992-2012 NR 27 TC 86 Z9 86 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 17 PY 2001 VL 87 IS 12 AR 122001 DI 10.1103/PhysRevLett.87.122001 PG 4 WC Physics, Multidisciplinary SC Physics GA 474TJ UT WOS:000171122700012 PM 11580499 ER PT J AU Hoang, GT Bourdelle, C Garbet, X Giruzzi, G Aniel, T Ottaviani, M Horton, W Zhu, P Budny, RV AF Hoang, GT Bourdelle, C Garbet, X Giruzzi, G Aniel, T Ottaviani, M Horton, W Zhu, P Budny, RV TI Experimental determination of critical threshold in electron transport on Tore Supra SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAT-TRANSPORT; IMPROVED CONFINEMENT; PLASMAS; FLUCTUATIONS; DISCHARGES; TOKAMAK; MODES AB In Tore Supra plasmas with fast wave electron heating, a critical threshold in the electron temperature gradient (delT(e)) is clearly observed, i.e., a finite value of delT(e) for which the turbulent heat diffusivity vanishes. The radial profile of this critical gradient is experimentally determined from a set of discharges characterized by similar plasma parameters with fast wave powers ranging from 0.75 to 7.4 MW. The dependence of the electron heat flux on the gradient length is found to be offset linearly. The offset term increases linearly with the ratio of the local magnetic shear to the safety factor. C1 CEA Cadarache, EURATOM Assoc, Dept Rech Fus Controlee, F-13108 St Paul Les Durance, France. Univ Texas, Inst Fus Studies, Austin, TX 78712 USA. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Hoang, GT (reprint author), CEA Cadarache, EURATOM Assoc, Dept Rech Fus Controlee, F-13108 St Paul Les Durance, France. RI ANIEL, Thierry/G-8734-2011 OI ANIEL, Thierry/0000-0002-2598-9551 NR 22 TC 91 Z9 92 U1 1 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 SEP 17 PY 2001 VL 87 IS 12 AR 125001 DI 10.1103/PhysRevLett.87.125001 PG 4 WC Physics, Multidisciplinary SC Physics GA 474TJ UT WOS:000171122700030 PM 11580517 ER PT J AU Montalenti, F Sorensen, MR Voter, AR AF Montalenti, F Sorensen, MR Voter, AR TI Closing the gap between experiment and theory: Crystal growth by temperature accelerated dynamics SO PHYSICAL REVIEW LETTERS LA English DT Article ID THIN-FILM GROWTH; MOLECULAR-DYNAMICS; INFREQUENT EVENTS; EPITAXIAL-GROWTH; SADDLE-POINTS; DIFFUSION; DEPOSITION; SURFACES; SIMULATION; MECHANISMS AB We present atomistic simulations of crystal growth where realistic experimental deposition rates are reproduced, without needing any a priori information on the relevant diffusion processes. Using the temperature accelerated dynamics method, we simulate the deposition of 4 monolayers (ML) of Ag/Ag(100) at the rate of 0.075 ML/s, thus obtaining a boost of several orders of magnitude with respect to ordinary molecular dynamics. In the temperature range analyzed (0-70 K), steering and activated mechanisms compete in determining the surface roughness. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Montalenti, F (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM montalenti@t12.lanl.gov RI Montalenti, Francesco/A-7738-2010 OI Montalenti, Francesco/0000-0001-7854-8269 NR 30 TC 65 Z9 65 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 17 PY 2001 VL 87 IS 12 AR 126101 DI 10.1103/PhysRevLett.87.126101 PG 4 WC Physics, Multidisciplinary SC Physics GA 474TJ UT WOS:000171122700041 PM 11580528 ER PT J AU Schumacher, AB Dodge, JS Carnahan, MA Kaindl, RA Chemla, DS Miller, LL AF Schumacher, AB Dodge, JS Carnahan, MA Kaindl, RA Chemla, DS Miller, LL TI Parity-forbidden excitations of Sr2CuO2Cl2 revealed by optical third-harmonic spectroscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID SUPERCONDUCTIVITY; INSTABILITY; INSULATORS; SCATTERING; EXCITONS; MODEL AB We present the first study of nonlinear optical third-harmonic generation (THG) in the strongly correlated charge-transfer insulator Sr2CuO2Cl2. For fundamental excitation in the. near infrared, the THG spectrum reveals a strongly resonant response for photon energies near 0.7 eV. Polarization analysis reveals this novel resonance to, be only partially accounted for by three-photon excitation to the optical charge-transfer exciton, and indicates that an even-parity state at 2 eV. with a(1g) symmetry, participates in the third-harmonic susceptibility. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. Univ Karlsruhe, Inst Angew Phys, D-76128 Karlsruhe, Germany. RP Schumacher, AB (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 21 TC 11 Z9 11 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 17 PY 2001 VL 87 IS 12 AR 127006 DI 10.1103/PhysRevLett.87.127006 PG 4 WC Physics, Multidisciplinary SC Physics GA 474TJ UT WOS:000171122700058 PM 11580545 ER PT J AU Wang, H Snell, G Hemmers, O Sant'Anna, MM Sellin, I Berrah, N Lindle, DW Deshmukh, PC Haque, N Manson, ST AF Wang, H Snell, G Hemmers, O Sant'Anna, MM Sellin, I Berrah, N Lindle, DW Deshmukh, PC Haque, N Manson, ST TI Dynamical relativistic effects in photoionization: Spin-orbit-resolved angular distributions of xenon 4d photoelectrons near the cooper minimum SO PHYSICAL REVIEW LETTERS LA English DT Article ID RANDOM-PHASE APPROXIMATION; INDEPENDENT-PARTICLE APPROXIMATION; HIGH-Z ELEMENTS; PHOTO-IONIZATION; HIGH-RESOLUTION; BRANCHING RATIO; CROSS-SECTION; OUTER SHELLS; XE; NEON AB Two decades ago, it was predicted [Y S. Kim et al., Phys. Rev. Lett. 46, 1326 (1981)] that relativistic effects should alter the dynamics of the photoionization process in. the vicinity of Cooper minima. The present experimental and theoretical study of the angular distributions of Xe 4d(3/2) and 4d(5/2) photoelectrons demonstrates this effect for the first time. The results clearly imply that relativistic effects are likely to be important for intermediate-Z atoms at most energies. C1 Univ Nevada, Dept Chem, Las Vegas, NV 89154 USA. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Indian Inst Technol, Dept Phys, Madras 600036, Chennai, India. Georgia State Univ, Dept Phys & Astron, Atlanta, GA 30030 USA. Clark Atlanta Univ, Ctr Theoret Studies Phys Syst, Atlanta, GA 30030 USA. Morehouse Coll, Dept Phys, Atlanta, GA 30030 USA. RP Wang, H (reprint author), Univ Nevada, Dept Chem, Las Vegas, NV 89154 USA. EM smanson@gsu.edu RI Sant'Anna, Marcelo/B-9355-2013 OI Sant'Anna, Marcelo/0000-0001-5342-5799 NR 47 TC 15 Z9 15 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 17 PY 2001 VL 87 IS 12 AR 123004 DI 10.1103/PhysRevLett.87.123004 PG 4 WC Physics, Multidisciplinary SC Physics GA 474TJ UT WOS:000171122700018 ER PT J AU Wright, DL Kasibhatla, PS McGraw, R Schwartz, SE AF Wright, DL Kasibhatla, PS McGraw, R Schwartz, SE TI Description and evaluation of a six-moment aerosol microphysical module for use in atmospheric chemical transport models SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID MARINE BOUNDARY-LAYER; PARTICLE-SIZE DISTRIBUTION; OPTICAL-PROPERTIES; ADVECTION SCHEME; MOMENTS; NUCLEATION; DYNAMICS; CONDENSATION; PARAMETERIZATION; COAGULATION AB We describe and evaluate a six-moment aerosol microphysical module, 6M, designed for implementation in atmospheric chemical transport models (CTMs). The module 6M is based upon the quadrature method of moments (QMOM) [McGraw, 1997] and the multiple isomomental distribution aerosol surrogate (MIDAS) method [Wright, 2000]. The module 6M evolves the lowest six radial moments of H2SO4-H2O aerosols for a comprehensive set of dynamical processes including the formation of new particles via binary H2SO4-H2O nucleation, condensational growth, coagulation, evolution due to cloud processing, size-resolved dry deposition, and water uptake and release with changing relative humidity. Performance of the moment-based aerosol evolution is examined and evaluated by comparison with results obtained using a high-resolution discrete model of the particle dynamics for a range of conditions representative of the boundary layer and lower troposphere. Overall, the performance of 6M is good relative to uncertainties associated with other processes represented in CTMs for the 30 test cases evaluated. Differences between 6M and the discrete model in the mass/volume moment and in the partitioning of sulfur (VI) between the gas and aerosol phases remain under 1% whenever significant, aerosol is present, and differences in particle number rarely exceed 15%. Estimates of cloud droplet number from 6M are on average within 16% of those of the discrete model, with a significant part,of these differences attributable to limitations of the discrete dynamics. Multimodal lognormal (MIDAS) surrogates to the underlying size distributions derived from the 6M moments are in good agreement with the benchmark size distributions. C1 Duke Univ, Nicholas Sch Environm, Durham, NC 27705 USA. Brookhaven Natl Lab, Dept Appl Sci, Atmospher Sci Div, Upton, NY 11973 USA. RP Wright, DL (reprint author), Duke Univ, Nicholas Sch Environm, Box 90328, Durham, NC 27705 USA. EM dwright@bnl.gov; psk@duke.edu; rlm@aerosol.das.bnl.gov; ses@bnl.gov RI Kasibhatla, Prasad/A-2574-2010; Schwartz, Stephen/C-2729-2008; OI Schwartz, Stephen/0000-0001-6288-310X; Kasibhatla, Prasad/0000-0003-3562-3737 NR 37 TC 18 Z9 18 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD SEP 16 PY 2001 VL 106 IS D17 BP 20275 EP 20291 DI 10.1029/2001JD900098 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 473KZ UT WOS:000171044200021 ER PT J AU Ferrare, RA Turner, DD Brasseur, LH Feltz, WF Dubovik, O Tooman, TP AF Ferrare, RA Turner, DD Brasseur, LH Feltz, WF Dubovik, O Tooman, TP TI Raman lidar measurements of the aerosol extinction-to-backscatter ratio over the Southern Great Plains SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SPECTRAL RESOLUTION LIDAR; SKY RADIANCE MEASUREMENTS; MID-ATLANTIC COAST; OPTICAL-PROPERTIES; WATER-VAPOR; ATMOSPHERIC AEROSOLS; TROPOSPHERIC AEROSOL; 6-WAVELENGTH LIDAR; SUN-PHOTOMETER; BOUNDARY-LAYER AB We derive profiles of the aerosol extinction-to-backscatter ratio, S-a, at 355 nm using aerosol extinction and backscatter profiles measured during 1998 and 1999 by the operational Raman lidar at the Department of Energy Atmospheric Radiation Measurement Program Southern Great Plains site in north central Oklahoma. Data from this Raman/Rayleigh-Mie lidar, which measures Raman scattering from nitrogen as well as the combined molecular (Rayleigh) and aerosol (Mie) scattering at the laser wavelength, are used to derive aerosol extinction and backscattering independently as a function of altitude. Because this lidar operates at 355 nm, where molecular backscattering is comparable to aerosol backscattering, S-a retrievals are generally limited to conditions where aerosol extinction at 355 nm is >0.03 km(-1). The mean value of S-a at 355 nm derived for this period was 68 sr with a standard deviation of 12 sr. S-a was generally about 5-10 sr higher during high aerosol optical thickness (AOT) (>0.3) conditions than during low AOT (<0.1). A similar increase in S-a was found when the relative humidity increased from 30 to 80%. Large (> 15%) variations in the vertical profile of S-a occurred about 30% of the time, which implies that significant variability in the vertical distribution of the aerosol size distribution, shape, and/or composition often occurs. The Raman lidar measurements of S-a were compared with estimates of particle size and refractive index derived from an algorithm that uses ground-based Sun photometer measurements of Sun and sky radiance. For 17 cases of coincident Raman lidar and Sun and sky radiance measurements, S-a was linearly correlated with the aerosol fine mode effective radius and the volume ratio of fine/coarse particles. C1 NASA, Langley Res Ctr, Sci Applicat Int Corp, Hampton, VA 23665 USA. Pacific NW Natl Lab, Richland, WA USA. Univ Wisconsin, Cooperat Inst Meteorol Satellite Studies, Madison, WI USA. NASA, Goddard Space Flight Ctr, Sci Syst & Applicat Inc, Greenbelt, MD 20771 USA. Sandia Natl Labs, Livermore, CA USA. RP Ferrare, RA (reprint author), NASA, Langley Res Ctr, Sci Applicat Int Corp, Hampton, VA 23665 USA. EM r.ferrare@larc.nasa.gov; dave.turner@pnl.gov; l.h.heilman@larc.nasa.gov; wayne.feltz@ssec.wisc.edu; dubovik@spamer.gsfc.nasa.gov; tooman@ca.sandia.gov RI Dubovik, Oleg/A-8235-2009 OI Dubovik, Oleg/0000-0003-3482-6460 NR 57 TC 65 Z9 65 U1 0 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 SEP 16 PY 2001 VL 106 IS D17 BP 20333 EP 20347 DI 10.1029/2000JD000144 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 473KZ UT WOS:000171044200024 ER PT J AU Heske, C Groh, U Fuchs, O Umbach, E Franco, N Bostedt, C Terminello, LJ Perera, RCC Hallmeier, KH Preobrajenski, A Szargan, R Zweigart, S Riedl, W Karg, F AF Heske, C Groh, U Fuchs, O Umbach, E Franco, N Bostedt, C Terminello, LJ Perera, RCC Hallmeier, KH Preobrajenski, A Szargan, R Zweigart, S Riedl, W Karg, F TI X-ray emission spectroscopy of Cu(In,Ga)(S,Se)(2)-based thin film solar cells: Electronic structure, surface oxidation, and buried interfaces SO PHYSICA STATUS SOLIDI A-APPLIED RESEARCH LA English DT Article; Proceedings Paper CT 3rd Brazilian-German Workshop on Applied Surface Science CY MAR 05-09, 2001 CL FLORIANOPOLIS, BRAZIL ID BATH DEPOSITION PROCESS; BAND-STRUCTURE; CUINSE2; FLUORESCENCE; SCATTERING; CDS; HETEROJUNCTION; EFFICIENCY AB The electronic and chemical structure of Cu(In,Ga)(S,Se)(2) (CIGSSe) thin film surfaces and of relevant interfaces in CIGSSe-based thin film solar cells is investigated with a combination of X-ray emission spectroscopy (XES) and photoelectron spectroscopy. Examples of sulfur L-2,L-3 XES spectra of CdS and CIGSSe are discussed in view of resonant excitation, surface oxidation, and chemical bonding. The combination of the two techniques proves to be a powerful tool to identify spectral features correlated to certain chemical states or bonds. By monitoring these features in interface formation sequences, chemical and electronic information about buried interfaces can be obtained, which will be discussed in detail for the ZnO/CIGSSe interface. The experimental results provide valuable information on the CIGSSe surface and the ZnO/CIGSSe interface and, in general, demonstrate some of the spectroscopic advantages of X-ray emission spectroscopy. C1 Univ Wurzburg, D-97074 Wurzburg, Germany. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Leipzig, Wilhelm Ostwald Inst Phys & Theoret Chem, D-04103 Leipzig, Germany. Siemens AG, D-87130 Munich, Germany. Siemens & Shell Solar, D-87139 Munich, Germany. RP Heske, C (reprint author), Univ Wurzburg, Hubland, D-97074 Wurzburg, Germany. RI Preobrajenski, Alexei/A-3150-2009 NR 42 TC 25 Z9 25 U1 1 U2 11 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0031-8965 J9 PHYS STATUS SOLIDI A JI Phys. Status Solidi A-Appl. Res. PD SEP 16 PY 2001 VL 187 IS 1 BP 13 EP 24 DI 10.1002/1521-396X(200109)187:1<13::AID-PSSA13>3.0.CO;2-D PG 12 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 480JJ UT WOS:000171458000005 ER PT J AU Su, H Hou, YJ Houk, RS Schrader, GL Yeung, ES AF Su, H Hou, YJ Houk, RS Schrader, GL Yeung, ES TI Combinatorial screening of heterogeneous catalysts in selective oxidation of naphthalene by laser-induced fluorescence imaging SO ANALYTICAL CHEMISTRY LA English DT Article ID SURFACE-ACTIVE SITES; LIBRARIES; DISCOVERY AB Heterogeneous catalysis is one of the most important processes in the petroleum and the chemical industries. To be able to screen catalysts at high throughput will dramatically improve performance and reduce costs. Here we used laser-induced fluorescence imaging as a high-throughput screening technique in the combinatorial discovery of active catalysts for naphthalene oxidation. Binary catalysts of V-Mo-O, V-Sn-O, V-Ti-O, and V-W-O in various 15-member libraries were screened. Laser ablation ICPMS was employed to confirm the composition of the individual catalysts in the combinatorial library. The addition Of MoO3, WO3, SnO2, and TiO2 to V2O5 did not improve the catalytic activity in the conversion of naphthalene to naphthoquinone, but the overall activity was found to increase for certain binary samples. The screening of ternary catalysts of V-Sn-Mo-O revealed that the combination of V (45%)-Sn (45%)-Mo (10%) gave 70% higher catalytic activity than pure V2O5 in converting naphthalene to naphthoquinone. Reaction temperature and sample preparation effects on the activity and selectivity of catalysts are also studied in a combinatorial manner. C1 Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Yeung, ES (reprint author), Iowa State Univ, Ames Lab, US DOE, Ames, IA 50011 USA. NR 15 TC 26 Z9 26 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 15 PY 2001 VL 73 IS 18 BP 4434 EP 4440 DI 10.1021/ac015513i PG 7 WC Chemistry, Analytical SC Chemistry GA 473LC UT WOS:000171044600007 PM 11575790 ER PT J AU Cook, RJ Champion, KM Giometti, CS AF Cook, RJ Champion, KM Giometti, CS TI Methanol toxicity and formate oxidation in NEUT2 mice SO ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS LA English DT Article ID OXIDE-TREATED RATS; NITROUS-OXIDE; 10-FORMYLTETRAHYDROFOLATE DEHYDROGENASE; HEPATIC TETRAHYDROFOLATE; METHIONINE; LIVER; COMPARTMENTATION; INACTIVATION; METABOLISM AB NEUT2 mice are deficient in cytosolic 10-formyltetrahydrofolate dehydrogenase (FDH; EC 1.5.1.6) which catalyzes the oxidation of excess folate-linked one-carbon units in the form of 10-formyltetrahydrofolate to CO and tetrahydrofolate (Champion et al, Proc. Natl Acad Sci. USA 91, 11338 - 11342, 1994). The absence of FDH should impair the oxidation of formate via the folate-dependent pathway and as a consequence render homozygous NEUT2 mice more susceptible to methanol toxicity. Normal (CB6-F1) and NEUT2 heterozygous and homozygous mice had essentially identical LD. values for methanol, 6.08, 6.00, and 6.03 g/kg, respectively. Normal mice oxidized low doses of [C-14]sodium formate (ip 5 mg/kg) to (CO2)-C-14, at approximately twice the rate of homozygous NEUT2 mice, indicating the presence of another formate-oxidizing system in addition to FDH. Treatment of mice with the catalase inhibitor, 3-aminotriazole (1 g/kg ip) had no effect on the rate of formate oxidation, indicating that at low concentrations formate was not oxidized peroxidatively by catalase. High doses of [C-14]sodium formate Up 100 mg/kg) were oxidized to (CO2)-C-14 at identical rates in normal and NEUT2 homozygous mice. Pretreatment with 3-aminotriazole (1 g/kg ip) in this instance resulted in a 40 and 50% decrease in formate oxidation to CO2 in both normal and homozygous NEUT2 mice, respectively. These results indicate that mice are able to oxidize formate to CO2 by at least three different routes: (1) folate-dependent via FDH at low levels of formate; (2) peroxidation by catalase at high levels of formate; and (3) by an unknown route(s) which appears to function at both low and high levels of formate. The implications of these observations are discussed in terms of the current hypotheses concerning methanol and formate toxicity in rodents and primates. (C) 2001 Academic Press. C1 Vanderbilt Univ, Sch Med, Dept Biochem, Nashville, TN 37232 USA. Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. RP Cook, RJ (reprint author), Vanderbilt Univ, Sch Med, Dept Biochem, 221 Kirkland Hall,Room 604 MRBI, Nashville, TN 37232 USA. FU NIDDK NIH HHS [R01-DK49563] NR 27 TC 23 Z9 23 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0003-9861 J9 ARCH BIOCHEM BIOPHYS JI Arch. Biochem. Biophys. PD SEP 15 PY 2001 VL 393 IS 2 BP 192 EP 198 DI 10.1006/abbi.2001.2485 PG 7 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 479LW UT WOS:000171406700002 PM 11556805 ER PT J AU Jager, HI Tyler, JA AF Jager, HI Tyler, JA TI Discussion on 'Movement rules for individual-based models of stream fish' [S.F. Railsback et al. 123 (1999) 73-89] SO ECOLOGICAL MODELLING LA English DT Editorial Material ID RAINBOW-TROUT; ENVIRONMENT; DECISIONS; BEHAVIOR; PREY C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Worcester Polytech Inst, Worcester, MA 01609 USA. RP Jager, HI (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM jagerhi@ornl.gov NR 21 TC 1 Z9 1 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3800 EI 1872-7026 J9 ECOL MODEL JI Ecol. Model. PD SEP 15 PY 2001 VL 143 IS 3 BP 245 EP 248 DI 10.1016/S0304-3800(01)00332-5 PG 4 WC Ecology SC Environmental Sciences & Ecology GA 481DY UT WOS:000171505700007 ER PT J AU Riley, RG Thompson, CJ Huesemann, MH Wang, ZM Peyton, B Fortman, T Truex, MJ Parker, KE AF Riley, RG Thompson, CJ Huesemann, MH Wang, ZM Peyton, B Fortman, T Truex, MJ Parker, KE TI Artificial aging of phenanthrene in porous silicas using supercritical carbon dioxide SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID DISTRIBUTED REACTIVITY MODEL; ORGANIC-COMPOUNDS; UNSATURATED CONDITIONS; HALOGENATED ORGANICS; SLOW DESORPTION; SEDIMENTS; SORPTION; SOIL; CHEMICALS; SOLIDS AB Expedited artificial aging is described and demonstrated using a novel system that circulates a solution of supercritical carbon dioxide and a hydrophobic organic sorbate (phenanthrene) through a closed loop containing a porous substrate. Unlike traditional methods used to simulate the natural aging process, our approach allows for realtime monitoring of sorption equilibria, and the process is highly accelerated due to the unique physical properties of supercritcal carbon dioxide. The effectiveness of the system to simulate aging was demonstrated with a series of experiments in which three silicas with varying particle and pore sizes were loaded with phenanthrene. Batch aqueous desorption experiments were used to evaluate the extent of the aging process. For the two types of particles containing the largest pores (i.e., mean diameters of 202 and 66 Angstrom), 95% and 86%, respectively, of the phenanthrene was released to the aqueous fraction within 3 h. In contrast, only 16% of the phenanthrene was released from particles having a mean pore diameter of 21 Angstrom after 24 h. These results were confirmed by the results from an aqueous column desorption experiment. Confounding factors that might contribute to slow aqueous desorption such as the hydration state of the particles' surfaces, the chemical form of the loaded phenanthrene, and the organic carbon content were investigated and/or normalized for all three particle types. Consequently, we were able to attribute the slow desorption behavior and the presence of the resistant fraction in the 21 A silica to pore effects. With properly designed experiments, the results of this study suggest that the supercritical fluid system could be extended to the study of contaminant aging and bioavailability in natural soils and sediments. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Pacific NW Natl Lab, Marine Sci Lab, Sequim, WA 99382 USA. Washington State Univ, Dept Chem Engn, Pullman, WA 99164 USA. RP Riley, RG (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. RI Wang, Zheming/E-8244-2010; OI Wang, Zheming/0000-0002-1986-4357; Peyton, Brent/0000-0003-0033-0651 NR 27 TC 4 Z9 5 U1 0 U2 7 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 SEP 15 PY 2001 VL 35 IS 18 BP 3707 EP 3712 DI 10.1021/es0020613 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 473PW UT WOS:000171055400018 PM 11783649 ER PT J AU Schneegurt, MA Jain, JC Menicucci, JA Brown, SA Kemner, KM Garofalo, DF Quallick, MR Neal, CR Kulpa, CF AF Schneegurt, MA Jain, JC Menicucci, JA Brown, SA Kemner, KM Garofalo, DF Quallick, MR Neal, CR Kulpa, CF TI Biomass byproducts for the remediation of wastewaters contaminated with toxic metals SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID HEAVY-METALS; AQUEOUS-SOLUTIONS; SACCHAROMYCES-CEREVISIAE; ASPERGILLUS-NIGER; REMOVAL; BIOSORPTION; RECOVERY; BINDING; CADMIUM; SPECTRA AB Pollution of the environment with toxic metals is widespread and often involves large volumes of wastewater. Remediation strategies must be designed to support high throughput while keeping costs to a minimum. Biosorption is presented as an alternative to traditional physicochemical means for removing toxic metals from wastewater. We have investigated the metal binding qualities of two biomass byproducts that are commercially available in quantity and at low cost, namely "spillage", a dried yeast and plant mixture from the production of ethanol from corn, and ground corn cobs used in animal feeds. The biomass materials effectively removed toxic metals, such as Cu, Cs, Mo, Ni, Pb, and Zn, even in the presence of competing metals likely to be found in sulfide mine tailing ponds. The effectiveness of these biosorbents was demonstrated using samples from the Berkeley Pit in Montana. Investigations included column chromatography and slurry systems, and linear distribution coefficients are presented. X-ray spectroscopy was used to identify the binding sites for metals adsorbed to the spillage material. The results of our experiments demonstrate that the biosorption of metals from wastewaters using biomass byproducts is a viable and cost-effective technology that should be included in process evaluations. C1 Wichita State Univ, Dept Biol Sci, Wichita, KS 67260 USA. Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Univ Notre Dame, Dept Biol Sci, Ctr Environm Sci & Technol, Notre Dame, IN 46556 USA. Univ Notre Dame, Dept Civil Engn & Geol Sci, Notre Dame, IN 46556 USA. RP Schneegurt, MA (reprint author), Wichita State Univ, Dept Biol Sci, Wichita, KS 67260 USA. EM mark.schneegurt@wichita.edu RI ID, MRCAT/G-7586-2011 NR 31 TC 75 Z9 77 U1 2 U2 20 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 SEP 15 PY 2001 VL 35 IS 18 BP 3786 EP 3791 DI 10.1021/es010766e PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 473PW UT WOS:000171055400029 PM 11783660 ER PT J AU Ryan, JA Zhang, PC Hesterberg, D Chou, J Sayers, DE AF Ryan, JA Zhang, PC Hesterberg, D Chou, J Sayers, DE TI Formation of chloropyromorphite in a lead-contaminated soil amended with hydroxyapatite SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SEQUENTIAL EXTRACTION PROCEDURE; AQUEOUS-SOLUTIONS; IMMOBILIZATION; PB; ORTHOPHOSPHATES; PYROMORPHITE; SOLUBILITY; APATITE; PH AB Conversion of soil Pb to pyromorphite [Pb-5(PO4)(3)Cl] was evaluated by reacting a Pb contaminated soil collected adjacent to a historical smelter with hydroxyapatite [Ca-5(PO4)(3)OH]. In a dialysis experiment where the soil and hydroxyapatite solids were placed in separate dialysis bags suspended in 0.01 M NaNO3 solution a crystalline precipitate, identified as chloropyromorphite, formed on the dialysis membrane containing the soil. The aqueous composition of the solution indicated that dissolution of solid-phase soil Pb was the rate-limiting step for pyromorphite formation. Addition of hydroxyapatite to the soil caused a decrease in each of the first four fractions of sequential extractable Pb and a 35% increase in the recalcitrant extraction residue, After a 240-d incubation at field-moisture content there was a further increase in the recalcitrant extraction residue fraction of the hydroxyapatite-amended soil to 45% of the total soil Pb. The increase in the extraction residue fraction in the hydroxyapatite amended 0-d incubated soil as compared to the control soil illustrates that the chemical extraction procedure itself caused changes in extractability. Thus,the chemical extraction procedure cannot easily be utilized to confirm changes occurring in amended soils. The further increase after the 240-d incubation implies that the reaction also occurs in the soil during incubation. Extended X-ray absorption fine structure (EXAFS) spectroscopy indicated that after the 240-d incubation the hydroxyapatite treatment caused a change in the average, local molecular bonding environment of soil Pb. Low-temperature EXAFS spectra (chi data and radial structure functions - RSFs) showed a high degree of similarity between the chemical extraction residue and synthetic pyromorphite, providing additional evidence that the change of soil Pb to pyromorphite is possible by simple amendments of hydroxyapatite to soil. C1 US EPA, Natl Risk Management Res Lab, Cincinnati, OH 45224 USA. Sandia Natl Labs, Dept Geochem, Albuquerque, NM 87185 USA. N Carolina State Univ, Dept Soil Sci, Raleigh, NC 27695 USA. N Carolina State Univ, Dept Phys, Raleigh, NC 27695 USA. RP Ryan, JA (reprint author), US EPA, Natl Risk Management Res Lab, 5995 Ctr Hill Ave, Cincinnati, OH 45224 USA. NR 29 TC 119 Z9 127 U1 2 U2 27 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 SEP 15 PY 2001 VL 35 IS 18 BP 3798 EP 3803 DI 10.1021/es010634l PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 473PW UT WOS:000171055400031 PM 11783662 ER PT J AU Mege, D Reidel, SP AF Mege, D Reidel, SP TI A method for estimating 2D wrinkle ridge strain from application of fault displacement scaling to the Yakima folds, Washington SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID BLIND THRUST FAULTS; PLANETS; SLIP AB The Yakima folds on the central Columbia Plateau are a succession of thrusted anticlines thought to be analogs of planetary wrinkle ridges. They provide a unique opportunity to understand wrinkle ridge structure. Field data and length-displacement scaling are used to demonstrate a method for estimating two-dimensional horizontal contractional strain at wrinkle ridges. Strain is given as a function of ridge length, and depends on other parameters that can be inferred from the Yakima folds and fault population displacement studies. Because ridge length can be readily obtained from orbital imagery, the method can be applied to any wrinkle ridge population, and helps constrain quantitative tectonic models on other planets. C1 Univ Paris 06, Lab Tecton, F-75252 Paris 05, France. Pacific NW Natl Lab, Richland, WA 99352 USA. Washington State Univ, Pullman, WA 99164 USA. RP Mege, D (reprint author), Univ Paris 06, Lab Tecton, Boite 129, F-75252 Paris 05, France. RI Mege, Daniel/A-2331-2009; OI Mege, Daniel/0000-0003-4304-9878 NR 25 TC 7 Z9 7 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 SEP 15 PY 2001 VL 28 IS 18 BP 3545 EP 3548 DI 10.1029/2001GL012934 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 473HN UT WOS:000171035000032 ER PT J AU Liao, XZ Zou, J Cockayne, DJH Jiang, ZM Wang, X AF Liao, XZ Zou, J Cockayne, DJH Jiang, ZM Wang, X TI Extracting composition and alloying information of coherent Ge(Si)/Si(001) islands from [001] on-zone bright-field diffraction contrast images SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID TRANSMISSION-ELECTRON-MICROSCOPY; INXGA1-XAS/GAAS QUANTUM DOTS; GE ISLANDS; STRAIN; SEGREGATION; SCATTERING; EVOLUTION; SI(100); SI(001); SHAPE AB Ge(Si)/Si(001) coherent islands grown at 700 degreesC by molecular beam epitaxy were investigated using transmission electron microscopy. [001] on-zone bright-field diffraction contrast imaging and image simulation techniques were used to investigate the structure of these coherent islands. Comparison of simulated and experimental images indicates nonuniform composition distribution within the coherent islands when the islands were grown at high temperatures (700 degreesC), but uniform composition for growth at lower temperatures (600 degreesC). (C) 2001 American Institute of Physics. C1 Univ Sydney, Australian Key Ctr Microscopy & Microanal, Sydney, NSW 2006, Australia. Univ Oxford, Dept Mat, Oxford OX1 3PH, England. Fudan Univ, Surface Phys Lab, Shanghai 200433, Peoples R China. RP Liao, XZ (reprint author), Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RI Liao, Xiaozhou/B-3168-2009; Zou, Jin/B-3183-2009 OI Liao, Xiaozhou/0000-0001-8565-1758; Zou, Jin/0000-0001-9435-8043 NR 19 TC 23 Z9 24 U1 2 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 2001 VL 90 IS 6 BP 2725 EP 2729 DI 10.1063/1.1394900 PG 5 WC Physics, Applied SC Physics GA 466LR UT WOS:000170647500014 ER PT J AU Walters, RJ Summers, GP Messenger, SR Romero, MJ Al-Jassim, MM Garcia, R Araujo, D Freundlich, A Newman, F Vilela, MF AF Walters, RJ Summers, GP Messenger, SR Romero, MJ Al-Jassim, MM Garcia, R Araujo, D Freundlich, A Newman, F Vilela, MF TI Electron beam induced current and cathodoluminescence study of proton irradiated InAsxP1-x/InP quantum-well solar cells SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB The effects of proton irradiation on strained InAsxP1-x/InP-based quantum well solar cells (QWSCs) have been investigated by the electron beam induced current (EBIC) and cathodoluminescence (CL) techniques. From analysis of the EBIC data, capture rates within the quantum well region have been estimated, from which the open circuit voltages of the cells were calculated and shown to agree well with the measured values. Diffusion lengths have been estimated from analysis of both the EBIC and CL measurements. The location of the energy levels of proton-induced defects and their effectiveness as nonradiative recombination centers have been determined from Arrhenius plots of the total CL intensity emitted from the quantum wells following irradiation. The results suggest that deeper and narrower quantum wells increase the sensitivity of QWSCs to radiation damage. (C) 2001 American Institute of Physics. C1 USN, Res Lab, Solid State Devices Branch, Washington, DC 20375 USA. SFA Inc, Largo, MD 20774 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Cadiz, E-1150 Cadiz, Spain. Univ Houston, Ctr Space Vacuum Epitaxy, Houston, TX 77240 USA. RP Walters, RJ (reprint author), USN, Res Lab, Solid State Devices Branch, Code 6825,4555 Overlook Ave SW, Washington, DC 20375 USA. OI Garcia Roja, Rafael/0000-0003-2867-7016 NR 12 TC 10 Z9 10 U1 0 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 2001 VL 90 IS 6 BP 2840 EP 2846 DI 10.1063/1.1389755 PG 7 WC Physics, Applied SC Physics GA 466LR UT WOS:000170647500032 ER PT J AU Orwa, JO Prawer, S Jamieson, DN Peng, JL McCallum, JC Nugent, KW Li, YJ Bursill, LA Withrow, SP AF Orwa, JO Prawer, S Jamieson, DN Peng, JL McCallum, JC Nugent, KW Li, YJ Bursill, LA Withrow, SP TI Diamond nanocrystals formed by direct implantation of fused silica with carbon SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID TETRAHEDRAL AMORPHOUS-CARBON; ION-BEAM SYNTHESIS; SEMICONDUCTOR NANOCRYSTALS; HIGH-TEMPERATURE; QUANTUM DOTS; RAMAN-SPECTROSCOPY; COPPER; GROWTH; FILMS; EXCITONS AB We report synthesis of diamond nanocrystals directly from carbon atoms embedded into fused silica by ion implantation followed by thermal annealing. The production of the diamond nanocrystals and other carbon phases is investigated as a function of ion dose, annealing time, and annealing environment. We observe that the diamond nanocrystals are formed only when the samples are annealed in forming gas (4% H in Ar). Transmission electron microscopy studies show that the nanocrystals range in size from 5 to 40 nm, depending on dose, and are embedded at a depth of only 140 nm below the implanted surface, whereas the original implantation depth was 1450 nm. The bonding in these nanocrystals depends strongly on cluster size, with the smaller clusters predominantly aggregating into cubic diamond structure. The larger clusters, on the other hand, consist of other forms of carbon such as i-carbon and n-diamond and tend to be more defective. This leads to a model for the formation of these clusters which is based on the size dependent stability of the hydrogen-terminated diamond phase compared to other forms of carbon. Additional studies using visible and ultraviolet Raman Spectroscopy, optical absorption, and electron energy loss spectroscopy reveal that most samples contain a mixture of sp(2) and sp(3) hybridized carbon phases. (C) 2001 American Institute of Physics. C1 Univ Melbourne, Sch Phys, Microanalyt Res Ctr, Parkville, Vic 3010, Australia. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Univ Melbourne, Sch Phys, Microanalyt Res Ctr, Parkville, Vic 3010, Australia. EM s.prawer@physics.unimelb.edu.au RI Jamieson, David/G-3753-2010; Orwa, Julius/C-3631-2011; OI Jamieson, David/0000-0001-7733-6715; PRAWER, STEVEN/0000-0002-4959-0828; Orwa, Julius/0000-0001-6041-6751 NR 45 TC 33 Z9 34 U1 5 U2 15 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 SEP 15 PY 2001 VL 90 IS 6 BP 3007 EP 3018 DI 10.1063/1.1388857 PG 12 WC Physics, Applied SC Physics GA 466LR UT WOS:000170647500058 ER PT J AU Winey, JM Gupta, YM Hare, DE AF Winey, JM Gupta, YM Hare, DE TI r-axis sound speed and elastic properties of sapphire single crystals SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SHOCK-WAVE; COMPRESSION; CONSTANTS AB The sound speed was measured for plane wave propagation along the normal to the (1 (1) over bar 02) plane of sapphire single crystals. The measured r-axis sound speed is significantly different (similar to7%) from measured c- and a-axis sound speeds. These results contradict the previous assumption that the mechanical response of sapphire is nearly isotropic. Also, the r axis is not a pure mode direction for longitudinal acoustic wave propagation. The measured r-axis sound speed was not consistent with calculations using the elastic constants reported for sapphire. This discrepancy arises because the elastic constants determined previously used crystallographic conventions different from those in current use. By rotating the coordinate system used for describing the material properties of sapphire in earlier work, consistency is achieved with the current crystallographic conventions. The effect of this coordinate transformation on the second-order elastic constants, the third-order elastic constants, and the photoelastic constants of sapphire is discussed. (C) 2001 American Institute of Physics. C1 Washington State Univ, Inst Shock Phys, Pullman, WA 99164 USA. Washington State Univ, Dept Phys, Pullman, WA 99164 USA. Univ Calif Lawrence Livermore Natl Labs, Livermore, CA 94551 USA. RP Winey, JM (reprint author), Washington State Univ, Inst Shock Phys, Pullman, WA 99164 USA. NR 18 TC 33 Z9 33 U1 0 U2 10 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 15 PY 2001 VL 90 IS 6 BP 3109 EP 3111 DI 10.1063/1.1391420 PG 3 WC Physics, Applied SC Physics GA 466LR UT WOS:000170647500072 ER PT J AU Zhai, HJ Liu, SR Li, X Wang, LS AF Zhai, HJ Liu, SR Li, X Wang, LS TI Photoelectron spectroscopy of mono-niobium carbide clusters NbCn-(n=2-7): Evidence for a cyclic to linear structural transition SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DENSITY-FUNCTIONAL CALCULATIONS; METAL-CARBON NANOCRYSTALS; ELECTRONIC-STRUCTURE; THERMODYNAMIC PROPERTIES; GROWTH PATHWAYS; METALLOCARBOHEDRENES; STABILITY; SPECTRA; IONS; CARS AB We investigated a series of mono-niobium carbide clusters, NbCn- (n = 2-7), using anion photoelectron spectroscopy. Vibrationally resolved photoelectron spectra were observed for NbC2- and NbC3-, which were both shown to have cyclic C-2v structures. Two isomers were observed for NbC4- and NbC5-. The weak and low electron binding energy isomers were shown to be cyclic structures forming a series with NbC2- and NbC3-, and all have similar and low electron binding energies. The main isomers of NbC4- and NbC5-, which possess much higher electron binding energies, were shown to be due to linear structures, which form a series with NbC6- and NbC7-. All the linear NbCn- clusters were observed to have high electron binding energies and exhibit an even-odd alternation, similar to that observed for pure linear carbon clusters in the same size range. A cyclic to linear structural transition was thus observed for the NbCn- clusters from NbC3- to NbC4-, with the cyclic structures favored for the smaller clusters and the linear isomers favored for the larger clusters. (C) 2001 American Institute of Physics. C1 Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Wang, LS (reprint author), Washington State Univ, Dept Phys, 2710 Univ Dr, Richland, WA 99352 USA. NR 50 TC 26 Z9 27 U1 2 U2 13 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 15 PY 2001 VL 115 IS 11 BP 5170 EP 5178 DI 10.1063/1.1395556 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 472NW UT WOS:000170991200025 ER PT J AU Gulley, GL Martin, JE AF Gulley, GL Martin, JE TI Stabilization of colloidal silica using polyols SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE aggregation; stabilization; colloidal silica; polyols ID HYDRATION FORCES; AGGREGATION; DEPOSITION; TURBIDITY AB We have discovered that small polyols are reasonably effective at stabilizing colloidal silica against aggregation, even under the conditions of high PH and salt concentration. Both quasielastic and elastic light scattering were used to show that these polyols dramatically decrease the aggregation rate of the suspension, changing the growth kinetics from diffusion-limited cluster-cluster aggregation to reaction-limited cluster-cluster aggregation. These polyols may be useful in the treatment of tank wastes at the Hanford site. (C) 2001 Academic Press. C1 Dominican Univ, Dept Nat Sci, River Forest, IL 60305 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Gulley, GL (reprint author), Dominican Univ, Dept Nat Sci, 7900 W Div St, River Forest, IL 60305 USA. NR 21 TC 9 Z9 9 U1 3 U2 12 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD SEP 15 PY 2001 VL 241 IS 2 BP 340 EP 345 DI 10.1006/jcis.2001.7718 PG 6 WC Chemistry, Physical SC Chemistry GA 472QG UT WOS:000170996000006 ER PT J AU Taddeucci, J Wohletz, KH AF Taddeucci, J Wohletz, KH TI Temporal evolution of the Minoan eruption (Santorini, Greece), as recorded by its Plinian fall deposit and interlayered ash flow beds SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE Santorini; Plinian-type eruptions; tephra; fragmentation ID VOLCANIC ASH; FRAGMENTATION; DISTRIBUTIONS; TRANSPORT AB The Plinian fall deposit of the Minoan eruption (Santorini, Greece) and its interlayered ash flow beds show textural, componentry and chemical trends indicative of their temporal evolution and conditions that lead to the ash-flow emplacement. The deposits have been sampled in detail at a selected locality, and the following features have been analyzed: (i) maximum clast size; (ii) grain size distribution; (iii) componentry; (iv) lithic types; (v) pumice morphology; (vi) pumice types; and (vii) pumice crystal abundance. Stratigraphic variations of these features are assumed to record changes that occurred during the eruption, including changes in eruptive plume height, nature and relative efficiency of the magma fragmentation process, conduit stability, and magma flow in the conduit. Based upon the inferred temporal changes, we propose the following eruption reconstruction. The sustained Plinian column activity reached its climax (in terms of mass eruption rate and plume altitude) soon after the beginning of the eruption, and subsequently began to gradually subside. As a result of eruption waning, the conduit walls began to collapse, causing an increase in the shear stress in the flowing vesicular magma and an increase in the efficiency of the magma fragmentation process. Eventually the conduit closed or became too narrow to support a high-standing eruption column, leading to ash flow eruption as a result of the collapse of what was left of the eruptive plume, and/or directly from emission of an overpressured jet. Subsequent conduit pressure increases led to conduit re-opening and a Plinian column with associated pumice fallout began anew. The eruptive magma fragmentation process is proposed to have been of a brittle nature and linked to the shear stress generated by conduit wall friction. Fragmentation efficiency is recorded by grain size distributions and free crystal contents of the deposits. (C) 2001 Elsevier Science Ltd All rights reserved. C1 Univ Rome La Sapienza, Dipartimento Sci Terra, Dottorato Ricerca, Rome, Italy. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Taddeucci, J (reprint author), Via Giannina Milli 42, I-00135 Rome, Italy. OI Taddeucci, Jacopo/0000-0002-0516-3699 NR 33 TC 16 Z9 17 U1 0 U2 10 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 SEP 15 PY 2001 VL 109 IS 4 BP 299 EP 317 DI 10.1016/S0377-0273(01)00197-4 PG 19 WC Geosciences, Multidisciplinary SC Geology GA 491ZJ UT WOS:000172140200004 ER PT J AU Peralta, P Ramamurty, U Suresh, S Campbell, GH King, WE Mitchell, TE AF Peralta, P Ramamurty, U Suresh, S Campbell, GH King, WE Mitchell, TE TI Effects of anisotropy and slip geometry on fatigue fracture of Cu/sapphire bicrystals SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT Annual 2000 TMS Meeting CY MAR 12-16, 2000 CL NASHVILLE, TENNESSEE SP Minerals Met & Mat Soc, Extract & Proc Div DE anisotropy; Cu/sapphire bicrystal; interfacial crack; compact tension ID COPPER-SAPPHIRE INTERFACES; CRACK-PROPAGATION; ALUMINA; RESISTANCE; EXTENSION; GROWTH AB Interfacial fatigue cracks were propagated in Cu/sapphire bicrystals with (110)Cu parallel to (10 (1) over bar0)Al(2)O(3)parallel to [0001]Al2O3[0001]Al2O3 to study the effect of anisotropy and slip geometry in the fracture process. Compact tension specimens with two different crystallographic crack growth directions were loaded to Delta K1a similar or equal to 2 Mpa m(1.2)with R(.)0. Interfacial cracks grew preferentially along (110),,, and less favorably along < 001 > (Cu). Large areas of the copper fracture surface were relatively featureless for crack growth along < 110 > (Cu), whereas well defined striations could be observed for the second direction. A refined elastic analysis of the anisotropic near-tip fields for the interfacial crack revealed that the preferential crack growth direction had the highest energy release rate and mode I crack tip opening displacement. The second direction corresponded to a minimum mode II mix. Similar correlations were found in other Cu/sapphire bicrystal experiments described in the literature. Dislocation nucleation from the interfacial crack tip is also analyzed. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Arizona State Univ, Dept Mech & Aerosp Engn, Tempe, AZ 85287 USA. MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Peralta, P (reprint author), Arizona State Univ, Dept Mech & Aerosp Engn, POB 876106, Tempe, AZ 85287 USA. RI Campbell, Geoffrey/F-7681-2010; Ramamurty, Upadrasta/E-5623-2011 NR 24 TC 7 Z9 7 U1 1 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 15 PY 2001 VL 314 IS 1-2 SI SI BP 55 EP 66 DI 10.1016/S0921-5093(00)01939-0 PG 12 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 451BX UT WOS:000169782200009 ER PT J AU Yang, B Liaw, PK Wang, H Jiang, L Huang, JY Kuo, RC Huang, JG AF Yang, B Liaw, PK Wang, H Jiang, L Huang, JY Kuo, RC Huang, JG TI Thermographic investigation of the fatigue behavior of reactor pressure vessel steels SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT Annual 2000 TMS Meeting CY MAR 12-16, 2000 CL NASHVILLE, TENNESSEE SP Minerals Met & Mat Soc, Extract & Proc Div ID GROWTH RATE PROPERTIES; TEMPERATURE AB The fatigue behavior of reactor pressure vessel (RPV) steels during fatigue testing was monitored by an advanced, high-speed, high-sensitivity, nondestructive evaluation (NDE) technique called infrared (IR) thermography. Five stages of temperature profiles during fatigue were recorded: an initial increase of the mean specimen temperature followed by a temperature decrease, a constant (equilibrium) temperature region, an abrupt temperature increase, and a temperature drop after the specimen failure. Using the state-of-the-art IR camera, the temperature profiles were recorded cycle by cycle during 20 Hz fatigue testing. A theoretical model combining the thermoelastic, inelastic, and heat-conduction effects were used to explain and predict the temperature evolution during fatigue. Specifically, the temperature evolution was predicted, and the results were found to be in good agreement with the experimental data. (C) 2001 Elsevier Science B.V, All rights reserved. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. INER, Lungtan 325, Taiwan. Taiwan Power Co, Nucl Operat Dept, Taipei 100, Taiwan. RP Yang, B (reprint author), Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. RI Wang, Hsin/A-1942-2013 OI Wang, Hsin/0000-0003-2426-9867 NR 26 TC 84 Z9 89 U1 1 U2 15 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 15 PY 2001 VL 314 IS 1-2 SI SI BP 131 EP 139 DI 10.1016/S0921-5093(00)01910-9 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 451BX UT WOS:000169782200019 ER PT J AU Tian, H Liaw, PK Wang, H Fielden, D Strizak, JP Mansur, LK DiStefano, JR AF Tian, H Liaw, PK Wang, H Fielden, D Strizak, JP Mansur, LK DiStefano, JR TI Influence of mercury environment on the fatigue behavior of spallation neutron source (SNS) target container materials SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT Annual 2000 TMS Meeting CY MAR 12-16, 2000 CL NASHVILLE, TN SP Minerals Met & Mat Soc, Extract & Proc Div DE spallation neutron source; mercury environment; fatigue behavior ID CRACK-GROWTH-BEHAVIOR; STAINLESS-STEELS; HYDROGEN; EMBRITTLEMENT AB The high-cycle fatigue behavior of 316 LN stainless steel (SS), the prime candidate target-container material for the spallation neutron source (SNS), was investigated in air and mercury at frequencies from 10 to 700 Hz with a R ratio of 0.1. A decrease in the fatigue life of 316 LN SS in air was observed with increasing frequency. However, little influence of frequency on fatigue life was found in mercury. An increase in the specimen temperature at 700 Hz seems to be the main factor that contributed to the decrease of the fatigue life in air, relative to that at 10 Hz. However, because of the cooling effect of mercury, only a small temperature increase was found at 700 Hz. and, therefore, there was little frequency influence in mercury. At 10 Hz, a shorter fatigue life of 316 LN SS was measured in mercury than in air at stresses greater than yield strength, which may have resulted from liquid metal embrittlement (LME). At lower stresses. no difference in fatigue lives between mercury and air was detected at 10 Hz. At 700 Hz, the fatigue life in mercury was longer than in air. The fatigue endurance limit measured at both frequencies in mercury and in air was approx. 350 MPa. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. RI Wang, Hsin/A-1942-2013 OI Wang, Hsin/0000-0003-2426-9867 NR 22 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 EI 1873-4936 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 15 PY 2001 VL 314 IS 1-2 SI SI BP 140 EP 149 DI 10.1016/S0921-5093(00)01919-5 PG 10 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 451BX UT WOS:000169782200020 ER PT J AU Jiang, L Brooks, CR Liaw, PK Wang, H Rawn, CJ Klarstrom, DL AF Jiang, L Brooks, CR Liaw, PK Wang, H Rawn, CJ Klarstrom, DL TI High-frequency metal fatigue: the high-cycle fatigue behavior of ULTIMET (R) alloy SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT Annual 2000 TMS Meeting CY MAR 12-16, 2000 CL NASHVILLE, TENNESSEE SP Minerals Met & Mat Soc, Extract & Proc Div DE high-cycle fatigue; high-frequency; temperature increase; crack initiation; cobalt-based alloy ID CRACK INITIATION; TEMPERATURE AB ULTIMET (R) alloy is a relatively new commercial Co-26Cr-9Ni (wt.%) alloy, which exhibits good resistance to both wear and corrosion. A state-of-the-art high-frequency, 1000-Hz, material test system was used to study the high-cycle fatigue behavior of ULTIMET alloy up to 10 degrees cycles. Fatigue experiments were conducted at high (1000 Hz) and conventional (20 Hz) frequencies in air at room temperature. The effects of the test frequency. the temperature increase during fatigue, and the change of crack initiation sites from the surface to subsurface on fatigue life are discussed. Although the fatigue life was comparable at test frequencies of 1000 and 20 Hz. the equilibrium temperature at 1000 Hz was considerably higher than that at 20 Hz. The fractographic study showed different morphologies of fracture surfaces at various frequencies. The high-cycle fatigue behavior of ULTIMET alloy at both high- and low-frequencies exhibited a typical two-stage fatigue-crack-growth process, i.e., (a) stage I fatigue-crack initiation in which the cracks formed on those planes most closely aligned with the maximum sheer-stress direction in the grains of the fatigue specimen; and (b) stage II fatigue-crack growth in which the maximum principal tensile stress controlled crack propagation in the region of the crack tip. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Haynes Int Inc, Kokomo, IN 46904 USA. RP Jiang, L (reprint author), GE, Corp Res & Dev, POB 8, Schenectady, NY 12301 USA. RI Wang, Hsin/A-1942-2013 OI Wang, Hsin/0000-0003-2426-9867 NR 26 TC 17 Z9 17 U1 1 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 15 PY 2001 VL 314 IS 1-2 SI SI BP 162 EP 175 DI 10.1016/S0921-5093(00)01928-6 PG 14 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 451BX UT WOS:000169782200023 ER PT J AU Porter, GA Liaw, PK Tiegs, TN Wu, KH AF Porter, GA Liaw, PK Tiegs, TN Wu, KH TI Fatigue and fracture behavior of nickel-titanium shape-memory alloy reinforced aluminum composites SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article; Proceedings Paper CT Annual 2000 TMS Meeting CY MAR 12-16, 2000 CL NASHVILLE, TENNESSEE SP Minerals Met & Mat Soc, Extract & Proc Div DE scanning electron microscopy; yield strength; ultimate strength ID MATRIX AB A shape-memory alloy, nickel-titanium (NiTi), has been distributed throughout an aluminum matrix, using powder-metallurgy processing, in the hope of using the shape-memory effect to achieve strengthening and improve the fatigue resistance, as compared with the aluminum matrix. The shape-memory effect was activated by cold rolling the samples at - 30 degreesC. Upon reheating to the austenite phase, the NiTi was expected to return to its original shape, while embedded in the aluminum matrix. This action created residual, internal stresses around each particle, which strengthened the material. The yield and ultimate strengths, and fatigue lives of the NiTi reinforced aluminum composites, have been improved considerably, as compared with the unreinforced material. The cross-sectional microstructures of the composites, as well as, the modes of crack growth, have been examined with scanning electron microscopy (SEM) to identify fatigue and fracture mechanisms. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Florida Int Univ, Dept Mech Engn, Miami, FL 33174 USA. RP Porter, GA (reprint author), Univ Tennessee, Dept Mat Sci & Engn, Knoxville, TN 37996 USA. OI Porter, Glen/0000-0001-5598-4041 NR 10 TC 21 Z9 22 U1 2 U2 13 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD SEP 15 PY 2001 VL 314 IS 1-2 SI SI BP 186 EP 193 DI 10.1016/S0921-5093(00)01915-8 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 451BX UT WOS:000169782200025 ER PT J AU Tsutakawa, SE Morikawa, K AF Tsutakawa, SE Morikawa, K TI The structural basis of damaged DNA recognition and endonucleolytic cleavage for very short patch repair endonuclease SO NUCLEIC ACIDS RESEARCH LA English DT Article ID SUBSTRATE-ASSISTED CATALYSIS; II RESTRICTION ENDONUCLEASES; ESCHERICHIA-COLI K-12; MISMATCH-REPAIR; CRYSTAL-STRUCTURE; GENE-PRODUCT; BINDING; MUTS; VSR; MECHANISM AB Endonucleases in DNA repair must be able to recognize damaged DNA as well as cleave the phosphodiester backbone. These functional prerequisites are manifested in very short patch repair (Vsr) endonuclease through a common endonuclease topology that has been tailored for recognition of TG mismatches. Structural and biochemical comparison with type II restriction enzymes illustrates how Vsr resembles these endonucleases in overall topology but also how Vsr diverges in terms of the detailed catalytic mechanism. A histidine and two metal-water clusters catalyze the phosphodiester cleavage. The mode of DNA damage recognition is also unique to Vsr. All other structurally characterized DNA damage-binding enzymes employ a nucleotide flipping mechanism for substrate recognition and for catalysis. Vsr, on the other hand, recognizes the TG mismatch as a wobble base pair and penetrates the DNA with three aromatic residues on one side of the mismatch. Thus, Vsr endonuclease provides important counterpoints in our understanding of endonucleolytic mechanisms and of damaged DNA recognition. C1 Lawrence Berkeley Natl Lab, Berkeley, CA USA. Biomol Engn Res Inst, Suita, Osaka, Japan. RP Morikawa, K (reprint author), Lawrence Berkeley Natl Lab, Berkeley, CA USA. NR 43 TC 13 Z9 14 U1 0 U2 0 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD SEP 15 PY 2001 VL 29 IS 18 BP 3775 EP 3783 DI 10.1093/nar/29.18.3775 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 477UD UT WOS:000171301900006 PM 11557809 ER PT J AU Shastri, SD Maser, JM Lai, B Tys, J AF Shastri, SD Maser, JM Lai, B Tys, J TI Microfocusing of 50 keV undulator radiation with two stacked zone plates SO OPTICS COMMUNICATIONS LA English DT Article DE X-ray optics; X-ray microfocusing; high-energy X-rays; zone plates ID X-RAYS; FOCUSING OPTICS; DIFFRACTION AB The limitations of current fabrication methods preclude producing an efficient Fresnel phase zone plate optimized for focusing high-energy (> 40 keV) synchrotron X-ray beams. To get around this difficulty, one can attempt a Multiple zone plate setup that distributes the focusing task among more than one element, each of which can be manufactured. The focusing of 50 keV undulator radiation to a 9 x 7 mum(2) spot size with a flux density gain of 24 was achieved using two stacked zone plates precisely aligned with respect to each other. The instrument was used to record elemental concentration maps of a geological inclusion specimen using X-ray fluorescence. The stacked zone plate approach is a viable option for microfocusing high-energy X-rays. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. Warsaw Univ, Heavy Ion Lab, PL-02093 Warsaw, Poland. RP Shastri, SD (reprint author), Argonne Natl Lab, Adv Photon Source, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Maser, Jorg/K-6817-2013 NR 16 TC 25 Z9 26 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD SEP 15 PY 2001 VL 197 IS 1-3 BP 9 EP 14 DI 10.1016/S0030-4018(01)01408-0 PG 6 WC Optics SC Optics GA 473YV UT WOS:000171077900002 ER PT J AU Fiedorowicz, H Bartnik, A Dunn, J Smith, RF Hunter, J Nilsen, J Osterheld, AL Shlyaptsev, VN AF Fiedorowicz, H Bartnik, A Dunn, J Smith, RF Hunter, J Nilsen, J Osterheld, AL Shlyaptsev, VN TI Demonstration of a neonlike argon soft-x-ray laser with a picosecond-laser-irradiated gas puff target SO OPTICS LETTERS LA English DT Article ID TRANSIENT GAIN; NM; AMPLIFICATION; SATURATION; IONS; BRIGHTNESS; EFFICIENT; TABLETOP; TITANIUM AB We demonstrate a neonlike argon-ion x-ray laser, using a short-pulse laser-irradiated gas puff target. The gas puff target was formed by pulsed injection of gas from a high-pressure solenoid valve through a nozzle in the form of a narrow slit and irradiated with a combination of long, 600-ps and short, 6-ps high-power laser pulses with a total of 10 J of energy in a traveling-wave excitation scheme. Lasing was observed on the 3p S-1(0) --> 3s(1)P(1) transition at 46.9 nm and the 3d(1)P(1) --> 3p(1)P(1) transition at 45.1 nm. A gain of 11 cm(-1) was measured on these transitions for targets up to 0.9 cm long. (C) 2001 Optical Society of America. C1 Mil Univ Technol, Inst Optoelect, PL-00908 Warsaw, Poland. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Davis, Livermore, CA 94550 USA. RP Fiedorowicz, H (reprint author), Mil Univ Technol, Inst Optoelect, Ulica Kaliskiego 2, PL-00908 Warsaw, Poland. NR 25 TC 18 Z9 18 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD SEP 15 PY 2001 VL 26 IS 18 BP 1403 EP 1405 DI 10.1364/OL.26.001403 PG 3 WC Optics SC Optics GA 471ED UT WOS:000170913900005 PM 18049619 ER PT J AU Manciu, M Sen, S Hurd, AJ AF Manciu, M Sen, S Hurd, AJ TI Impulse propagation in dissipative and disordered chains with power-law repulsive potentials SO PHYSICA D LA English DT Article DE solitary wave; disordered chain; power-law repulsive potential ID SOLITON-LIKE PULSES; GRANULAR COLUMNS; HERTZIAN CHAINS; QUARTZ BEADS; WAVES; BACKSCATTERING; DYNAMICS AB We report particle dynamics based studies of impulse propagation in a chain of elastic beads with dissipative contacts and with randomly distributed masses. The interaction between the beads is characterized by the potential V(delta) similar to delta (n), delta greater than or equal to 0 being grain overlap, n > 2 and at zero external loading, i.e., under conditions of "sonic vacuum" in which sound cannot propagate through the chain [J. Appl. Mech. Technol. Phys. 5 (1983) 733]. In the earlier work, we have confirmed the studies of Nesterenko and coworkers and have reported that impulses propagate as solitary waves in the system of interest in the absence of dissipation and disorder [Physica A 268 (1999) 644]. In the present study, we first discuss the effects of restitution and velocity dependent friction on the propagation of the impulse. We next report that the maximum energy Emax of the solitary wave as it propagates from a chain of monodisperse grains of mass m to a chain with masses m(1 + r(z)epsilon), where -1 less than or equal to r(z) less than or equal to 1 and epsilon = const. that measures the degree of randomness, decays with linear distance traveled z as exp(-alpha (E)z), alpha (E) similar to epsilon (2+f(n)), f(n) being some n dependent constant for 2 < n < infinity. In monodisperse chains, the velocity of the solitary wave c similar to E-max((n - 2)/2n). In polydisperse chains, we show that the propagation speed of a non-dispersive solitary wave decays with distance as exp(-alpha (c)z), where alpha (c) = alpha (E)(n - 2)/2n. (C) 2001 Elsevier Science B.V. All rights reserved. C1 SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA. SUNY Buffalo, Ctr Adv Photon & Elect Mat, Buffalo, NY 14260 USA. SUNY Buffalo, Dept Chem Engn, Buffalo, NY 14260 USA. Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. RP Sen, S (reprint author), SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA. RI Manciu, Marian/C-7247-2017 OI Manciu, Marian/0000-0003-4821-4131 NR 19 TC 60 Z9 59 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD SEP 15 PY 2001 VL 157 IS 3 BP 226 EP 240 DI 10.1016/S0167-2789(01)00302-5 PG 15 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 466YQ UT WOS:000170674100005 ER PT J AU Schmidt, TJ Stamenkovic, VR Lucas, CA Markovic, NM Ross, PN AF Schmidt, TJ Stamenkovic, VR Lucas, CA Markovic, NM Ross, PN TI Surface processes and electrocatalysis on the Pt(hkl)/Bi-solution interface SO PHYSICAL CHEMISTRY CHEMICAL PHYSICS LA English DT Article ID FORMIC-ACID OXIDATION; IRREVERSIBLY ADSORBED BISMUTH; DEFINED PLATINUM SURFACES; SINGLE-CRYSTAL SURFACES; MONOXIDE ADLAYER STRUCTURES; MODIFIED PT(111) ELECTRODES; POISON FORMATION REACTION; ROTATING-DISK ELECTRODE; OXYGEN REDUCTION; CARBON-MONOXIDE AB In this article we review the most important findings for Bi modified Pt single crystal electrodes. The main focus is on results obtained on Pt(111)-Bi-ir but also some data for Pt(100)-Bi-ir are provided. Our own data are discussed in the light of previous data from the literature. By making use of in situ surface X-ray scattering in combination with ex situ X-ray photoelectron spectroscopy and cyclic voltammetry it is possible to establish a link between surface atomic structures and electrochemical surface processes. In short, Bi-ir was found to remain in its zero-valent state over the whole potential range. Besides a physical site blocking effect, Bi-ir alters the adsorption properties of H-upd, OHad, and anions from the supporting electrolyte due to electronic modifications of the platinum surface atoms. Rotating (ring-)disk electrode measurements were carried out to study the kinetics of H-2, CO or HCOOH electrooxidation on Pt(111)-Bi-ir or the oxygen reduction reaction on Pt(100)-Bi-ir, respectively. The kinetics of CO oxidation (both CO stripping and continuous CO oxidation) is accelerated initially on the Bi-ir modified Pt(111) surface compared to pure Pt(111) electrodes. The same effect was observed during the oxidation of formic acid. The oxygen reduction activity on Pt(100)-Bi-ir is reduced vs. pure Pt(100) due to the reduced number of active Pt sites for the reaction (site blocking). At negative potentials, however, the formation of peroxide is enhanced on the Bi-ir modified electrode. Hence, the selectivity of oxygen reduction to H2O2 (2-electron reduction) es. the reduction to H2O (4-electron reduction) is enhanced. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. RP Schmidt, TJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Schmidt, Thomas/A-2586-2010; OI Schmidt, Thomas/0000-0002-1636-367X; Lucas, Christopher/0000-0001-5743-3868 NR 92 TC 23 Z9 23 U1 2 U2 20 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1463-9076 J9 PHYS CHEM CHEM PHYS JI Phys. Chem. Chem. Phys. PD SEP 15 PY 2001 VL 3 IS 18 BP 3879 EP 3890 DI 10.1039/b102388h PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 477YG UT WOS:000171313700001 ER PT J AU Cancio, AC Chou, MY Hood, RQ AF Cancio, AC Chou, MY Hood, RQ TI Comparative study of density-functional theories of the exchange-correlation hole and energy in silicon SO PHYSICAL REVIEW B LA English DT Article ID GENERALIZED GRADIENT APPROXIMATION; QUANTUM MONTE-CARLO; KOHN-SHAM EXCHANGE; ELECTRON-GAS; NONLOCAL APPROXIMATION; GROUND-STATE; SEMICONDUCTORS; FORMALISM; SYSTEMS; SURFACE AB We present a detailed study of the exchange-correlation hole and exchange-correlation energy per particle in the Si crystal as calculated by the variational Monte Carlo method and predicted by various density-functional models. Nonlocal density-averaging methods prove to be successful in correcting severe errors in the local-density approximation (LDA) at low densities where the density changes dramatically over the correlation length of the LDA hole. but fail to provide systematic improvements at higher densities where the effects of density inhomogeneity are more subtle. Exchange and correlation considered separately show a sensitivity to the nonlocal semiconductor-crystal environment, particularly within the Si bond. which is not predicted by the nonlocal approaches based on density averaging. The exchange hole is well described by a bonding-orbital picture, while the correlation hole has a significant component due to the polarization of the nearby bonds, which partially screens out the anisotropy in the exchange hole. C1 Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. RI Chou, Mei-Yin/D-3898-2012; OI Cancio, Antonio/0000-0001-6313-0329 NR 55 TC 11 Z9 11 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 11 AR 115112 DI 10.1103/PhysRevB.64.115112 PG 15 WC Physics, Condensed Matter SC Physics GA 474ZG UT WOS:000171136700050 ER PT J AU Chang, CM Neto, AHC Bishop, AR AF Chang, CM Neto, AHC Bishop, AR TI Phonons and solitons in one-dimensional Mott insulators SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-TRANSFER; CONDUCTORS; DNA AB We study the problem of one-dimensional Luttinger liquids in the insulating Mott-Hubbard phase in the presence of acoustic phonons in the semiclassical limit. We show that solitonic excitations can propagate freely in the system and the energy required to produce a soliton is reduced by a polaronic effect. We find a critical value of the electron-phonon coupling constant for which this energy vanishes. C1 Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Boston Univ, Dept Phys, Boston, MA 02215 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Chang, CM (reprint author), Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. RI Castro Neto, Antonio/C-8363-2014 OI Castro Neto, Antonio/0000-0003-0613-4010 NR 14 TC 0 Z9 0 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 11 AR 113406 PG 3 WC Physics, Condensed Matter SC Physics GA 474ZG UT WOS:000171136700034 ER PT J AU Coulthard, I Sham, TK Hu, YF Naftel, SJ Kim, PS Freeland, JW AF Coulthard, I Sham, TK Hu, YF Naftel, SJ Kim, PS Freeland, JW TI Threshold behavior of the Cu L3M4,5M4,5 Auger effect of Cu metal at the L-3 edge SO PHYSICAL REVIEW B LA English DT Article ID SYNCHROTRON-RADIATION; RESONANT RAMAN; AU ALLOYS; SPECTRA; RESOLUTION; DENSITY; STATES; DECAY AB The Cu L3M4,5M4,5 Auger effect from Cu metal resulting from photoexcitation across the Cu L-3 edge has been investigated. We observe that (a) the resonant Auger features (lack of satellites below the (1)G line and narrower linewidths) are noticeably different from those of normal Auger excited with photon energy far above the threshold. (b) the Auger patterns exhibit a dispersion associated with varying excitation photon energy slightly below the threshold, in accordance with the resonant Raman effect, and (c) on the lower kinetic-energy side of the (1)G line there exists a shoulder not predicted by atomic theory this feature skews the (1)G line and is attributed to density-of-state effects. This threshold behavior and its implications are discussed in terms of multielectron processes, resonant x-ray Raman scattering, and sublifetime x-ray-absorption near-edge structure measurements using a partial Auger yield. C1 Univ Western Ontario, Dept Chem, London, ON N6A 5B7, Canada. Univ Saskatchewan, Canadian Light Source, Saskatoon, SK S7N 5C6, Canada. Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Coulthard, I (reprint author), Univ Western Ontario, Dept Chem, London, ON N6A 5B7, Canada. NR 26 TC 7 Z9 7 U1 2 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 11 AR 115101 DI 10.1103/PhysRevB.64.115101 PG 6 WC Physics, Condensed Matter SC Physics GA 474ZG UT WOS:000171136700039 ER PT J AU Dean, DJ Strayer, MR Wells, JC AF Dean, DJ Strayer, MR Wells, JC TI Quantum dots in magnetic fields: Thermal response of broken-symmetry phases SO PHYSICAL REVIEW B LA English DT Article ID MAXIMUM-DENSITY-DROPLET; ARTIFICIAL ATOMS; STATISTICS; LEVEL; ELECTRONS; SPECTRA; SYSTEMS; ENERGY; SHAPE AB We investigate the thermal properties of circular semiconductor quantum dots in high magnetic fields using finite-temperature Hartree-Fock techniques. We demonstrate that for a given magnetic field strength quantum dots undergo various shape phase transitions as a function of temperature, and we outline possible observable consequences. C1 Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. RP Dean, DJ (reprint author), Oak Ridge Natl Lab, Ctr Engn Sci Adv Res, Oak Ridge, TN 37831 USA. RI Wells, Jack/D-3675-2016; OI Wells, Jack/0000-0002-5083-3030; Dean, David/0000-0002-5688-703X NR 22 TC 6 Z9 6 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 125305 DI 10.1103/PhysRevB.64.125305 PG 5 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400066 ER PT J AU Diaz, J Anders, S Zhou, X Moler, EJ Kellar, SA Hussain, Z AF Diaz, J Anders, S Zhou, X Moler, EJ Kellar, SA Hussain, Z TI Analysis of the pi* and sigma* bands of the x-ray absorption spectrum of amorphous carbon SO PHYSICAL REVIEW B LA English DT Article ID DIAMOND-LIKE-CARBON; K-SHELL EXCITATION; FINE-STRUCTURE; THIN-FILMS; THERMAL-STABILITY; ARC DEPOSITION; AB-INITIO; GAS-PHASE; PHOTOEMISSION; GRAPHITE AB The same method used to determine sigma* excitations in the x-ray-absorption spectra of organic molecules is applied to analyze the structure of the sigma* band in the x-ray absorption spectra of amorphous carbon (a-C) films. The analysis assumes that only a sigma bond interaction to first neighbors is relevant to explain the structure of the sigma* band in a-C films. This is justified by the local character of the x-ray absorption probe and the short-range order existing in these films. The identification of the different sigma* components is based on the dependence of the sigma* binding energy with bond distance. The sigma* band is built up by summing the components resulting from the possible different types of sigma bonds in a-C. This method serves to separate the pi* states from the sigma* states and to identify the kind of chemical bonds existing between carbon atoms. This analysis yields a proportion of sp(3)-bonded atoms of 60% in a film with a density of about 2.9 g/cm(3), which is a value closer to what is expected from theoretical calculations. The analysis identifies a component at about 288.5 eV which is associated to strained sigma bonds of the type of the existing in sp(3) bonded rings like cyclopropene. Raman and photoemission spectroscopies help in the interpretation of the x-ray absorption spectra and the assignment of the sigma* components. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Univ Oviedo, Dept Fis, E-33007 Oviedo, Spain. RP Diaz, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Diaz, Javier/F-2381-2016; Raoux, Simone/G-3920-2016 NR 58 TC 50 Z9 50 U1 0 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 125204 DI 10.1103/PhysRevB.64.125204 PG 19 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400053 ER PT J AU Feibelman, PJ AF Feibelman, PJ TI Surface-diffusion mechanism versus electric field: Pt/Pt(001) SO PHYSICAL REVIEW B LA English DT Article ID ABINITIO MOLECULAR-DYNAMICS; TOTAL-ENERGY CALCULATIONS; WAVE BASIS-SET; ULTRASOFT PSEUDOPOTENTIALS; SELF-DIFFUSION; PT(111); SYSTEMS; METALS; ADSORPTION; TRANSITION AB Ab initio calculations agree with field ion microscopy (FIM) that the barrier to substitutional diffusion of a Pt atom on Pt(001) varies linearly with external electric field. changing similar to0.1 eV per V/Angstrom and increasing for fields oriented to push electrons into the surface. But with a computed hopping barrier remaining >0.5 eV higher than that for substitution, they contradict the idea that a change in FIM site visitation at fields of 1.5-2 V/Angstrom and temperatures similar to 265-284 K can be attributed to the onset of hopping. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 34 TC 43 Z9 43 U1 3 U2 15 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 125403 DI 10.1103/PhysRevB.64.125403 PG 6 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400092 ER PT J AU Funk, DJ Moore, DS Gahagan, KT Buelow, SJ Reho, JH Fisher, GL Rabie, RL AF Funk, DJ Moore, DS Gahagan, KT Buelow, SJ Reho, JH Fisher, GL Rabie, RL TI Ultrafast measurement of the optical properties of aluminum during shock-wave breakout SO PHYSICAL REVIEW B LA English DT Article ID FREQUENCY-DOMAIN INTERFEROMETER; ABSORPTION; PRESSURE; PHASE AB We have used high-resolution frequency domain interferometry to make ultrafast measurements of shock-induced changes in the optical properties of thin aluminum targets. Measurements with an 800 nm probe wavelength found an unexpected phase shift during a 4.65 GPa shock breakout. Further measurements at 400 nm associate this phase shift with the pressure dependence of the 1.5 eV interband transition in aluminum. Data taken at several angles of incidence allowed the separation of optical from material motion effects, yielding an effective complex index for the shocked material. RP Funk, DJ (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Moore, David/C-8692-2013 NR 17 TC 21 Z9 22 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 11 AR 115114 DI 10.1103/PhysRevB.64.115114 PG 5 WC Physics, Condensed Matter SC Physics GA 474ZG UT WOS:000171136700052 ER PT J AU Jiang, W Weber, WJ AF Jiang, W Weber, WJ TI Multiaxial channeling study of disorder accumulation and recovery in gold-irradiated 6H-SiC SO PHYSICAL REVIEW B LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; SILICON-CARBIDE; INDUCED AMORPHIZATION; ANNEALING BEHAVIOR; LATTICE DISPLACEMENTS; COMPUTER-SIMULATION; DEFECT PRODUCTION; ION-IMPLANTATION; IN-SITU; CERAMICS AB Single crystal 6H-SiC has been irradiated 60 degrees off normal with 2 MeV Au2+ ions at 300 K to fluences of 0.029, 0.058, and 0.12 ions/nm(2), which produced relatively tow damage levels. The disorder profiles as a function of ion fluence on both the Si and C sublattices have been determined simultaneously in situ using Rutherford backscattering and nuclear reaction analysis with 0.94 MeV D+ ions in channeling geometry along the [0001], [1 (1) over bar 02], and [10 (1) over bar1] axes. Along the [0001] axis at these low doses, similar levels of Si and C disorder are observed, and the damage accumulation is linear with dose. However, along (1 (1) over bar 02) and [10 (1) over bar1], the disorder accumulation is larger and increases sublinearly with dose. Furthermore, a higher level of C disorder than Si disorder is observed along the [1 (1) over bar 02] and [10 (1) over bar1] axes, which is consistent with a smaller threshold displacement energy on the C sublattice in SiC. The mean lattice displacement, perpendicular to each corresponding axis, ranges from 0.014 to 0.037 nn for this range of ion fluences. A steady accumulation of small displacements due to lattice stress is observed along the [10 (1) over bar1] axis, and a detectable reduction of the lattice stress perpendicular to the [0001] axis occurs at 0.12 Au2+/nm(2). There is only a moderate recovery of disorder, produced at and below 0.058 Au2+/nm(2), during thermal annealing at 570 K; more significant recovery is observed for 0.12 Au2+/nm(2) along both the [0001] and [1 (1) over bar 02] axes. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Jiang, W (reprint author), Pacific NW Natl Lab, MSIN K8-93,POB 999, Richland, WA 99352 USA. EM Weilin.Jiang@pnl.gov RI Weber, William/A-4177-2008; OI Weber, William/0000-0002-9017-7365; Jiang, Weilin/0000-0001-8302-8313 NR 46 TC 43 Z9 43 U1 1 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 125206 DI 10.1103/PhysRevB.64.125206 PG 11 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400055 ER PT J AU Kent, PRC Zunger, A AF Kent, PRC Zunger, A TI Theory of electronic structure evolution in GaAsN and GaPN alloys SO PHYSICAL REVIEW B LA English DT Review ID MOLECULAR-BEAM EPITAXY; NITROGEN-PAIR LUMINESCENCE; III-V SEMICONDUCTORS; DEEP IMPURITY LEVELS; BAND-GAP; QUANTUM-WELLS; COMPOSITION-DEPENDENCE; CHEMICAL TRENDS; COVALENT SEMICONDUCTORS; OPTICAL-PROPERTIES AB Using the empirical pseudopotential method and large atomistically relaxed supercells, we have systematically studied the evolution of the electronic structure of GaP1-xNx and GaAs1-xNx, from the dilute nitrogen impurity regime to the nascent nitride alloy. We show how substitutional nitrogen forms perturbed host states (PHS) inside the conduction band, whereas small nitrogen aggregates form localized cluster states (CS) in the band gap. By following the evolution of these states and the "perturbed host states" with increasing nitrogen composition, we propose a new model for low-nitrogen-content GaAs1-xNx and GaP1-xNx alloys: As the nitrogen composition increases. the energy of the CS is pinned while the energy of the PHS plunges down as the nitrogen composition increases. The impurity limit (PHS above CS) is characterized by strongly localized wave functions, low pressure coefficients, and sharp emission lines from the CS. The amalgamation limit (PHS overtake the CS) is characterized by a coexistence of localized states (leading to high effective mass, exciton localization, Stokes shift in emission versus absorption) overlapping delocalized PHS (leading to asymmetrically broadened states, low temperature coefficeint, delocalized E+ band at higher energies). The alloy! limit (PHS well below CS) may not have been reached experimentally, but is predicted to be characterized by conventional extended states. Our theory shows that these alloy systems require a polymorphous description, permitting the coexistence of many different local environments, rather than an isomorphous model that focuses on few impurity-host motifs. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Kent, Paul/A-6756-2008 OI Kent, Paul/0000-0001-5539-4017 NR 107 TC 313 Z9 316 U1 3 U2 46 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 11 AR 115208 DI 10.1103/PhysRevB.64.115208 PG 23 WC Physics, Condensed Matter SC Physics GA 474ZG UT WOS:000171136700062 ER PT J AU Lee, SJ Park, JM Wiener, TA Miller, LL Lynch, DW AF Lee, SJ Park, JM Wiener, TA Miller, LL Lynch, DW TI Optical properties and electronic structure of MgAuSn SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-CRYSTALS; CU; EXCHANGE; ALLOYS; PHASES; AG AB The optical conductivity spectrum of single-crystal MgAuSn was measured by spectroscopic ellipsometry in the energy range 1.5-5.0 eV. The spectrum has a large peak at 2.9 eV and a small shoulder around 4.3 eV. The band structure, density of states, and interband contribution to the optical conductivity were calculated with the tight-binding linear muffin-tin orbital method in the atomic-sphere approximation. The intraband contribution to the optical conductivity was added using the Drude response fitted to the experimental data. The total theoretical spectrum, including the intraband contribution, agrees well with experimental data. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. RP Lee, SJ (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 20 TC 3 Z9 3 U1 1 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 125112 DI 10.1103/PhysRevB.64.125112 PG 6 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400035 ER PT J AU Lyo, SK Huang, DH AF Lyo, SK Huang, DH TI Multisublevel magnetoquantum conductance in single and coupled double quantum wires SO PHYSICAL REVIEW B LA English DT Article ID INPLANE MAGNETIC-FIELDS; QUANTIZED CONDUCTANCE; MAGNETORESISTANCE; TRANSPORT; WELLS; SCATTERING; RESISTANCE; SUBBANDS AB We study the ballistic and diffusive magnetoquantum transport using a typical quantum point contact geometry for single and tunnel-coupled double wires that are wide (less than or similar to1 mum) in one perpendicular direction with densely populated sublevels and extremely confined in the other perpendicular (i.e., growth) direction. A general analytic solution to the Boltzmann equation is presented for multisublevel elastic scattering at low temperatures. The solution is employed to study interesting magnetic-field dependent behavior of the conductance such as a large enhancement and quantum oscillations of the conductance for various structures and field orientations. These phenomena originate from the following field-induced properties: magnetic confinement, displacement of the initial- and final-state wave functions for scattering, variation of the Fermi velocities, mass enhancement, depopulation of the sublevels and anticrossing (in double quantum wires). The magnetoconductance is strikingly different in long diffusive (or rough. dirty) wires from the quantized conductance in short ballistic (or clean) wires. Numerical results obtained for the rectangular confinement potentials in the growth direction are satisfactorily interpreted in terms of the analytic solutions based on harmonic confinement potentials. Some of the predicted features of the field-dependent diffusive and quantized conductances are consistent with recent data from GaAs/AlxGa1-xAs double quantum wires. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. USAF, Res Lab, VSSS, Kirtland AFB, NM 87117 USA. RP Lyo, SK (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 21 TC 17 Z9 17 U1 1 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 11 AR 115320 DI 10.1103/PhysRevB.64.115320 PG 13 WC Physics, Condensed Matter SC Physics GA 474ZG UT WOS:000171136700084 ER PT J AU Lyo, SK AF Lyo, SK TI Photon-assisted transmission through a double-barrier structure SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM-WELLS; SCATTERING; TRANSPORT; THZ; DOT AB We study multiphoton-assisted transmission of electrons through single-step, single-barrier and double-barrier potential-energy structures as a function of the photon energy and the temperature. Sharp resonances are obtained for the spectra of the tunneling current and are relevant to infrared detectors. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Lyo, SK (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 11 AR 113311 PG 4 WC Physics, Condensed Matter SC Physics GA 474ZG UT WOS:000171136700026 ER PT J AU Perkins, JD Mascarenhas, A Geisz, JF Friedman, DJ AF Perkins, JD Mascarenhas, A Geisz, JF Friedman, DJ TI Conduction-band-resonant nitrogen-induced levels in GaAs1-xNx with x < 0.03 SO PHYSICAL REVIEW B LA English DT Article ID SPECTROSCOPIC ELLIPSOMETRY; RAMAN-SCATTERING; QUANTUM-WELLS; SOLAR-CELLS; GAAS; ALLOYS; GAP; STATES; ELECTROREFLECTANCE; TRANSITIONS AB We report electroreflectance spectra between 1 and 4 eV for GaAs1-xNx samples with x<3%. In addition to four intrinsic GaAs transitions, three nitrogen-induced optical transitions, E+, E+ + (0), and E*, were observed. The weak and heretofore unknown E* transition was observed in four samples with 0.1 to 2.4 % nitrogen and occurs 0.1 to 0.3 eV below the similar to3 eV intrinsic E-1 transition. Opposite to E+, E* decreases in energy with increasing nitrogen content. Furthermore, in the dilute limit, both E+ and E* appear to converge to the known conduction-band-resonant nitrogen-impurity level N-x. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Perkins, JD (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM john_perkins@nrel.gov NR 32 TC 24 Z9 24 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 121301 DI 10.1103/PhysRevB.64.121301 PG 4 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400010 ER PT J AU Raczkowski, D Canning, A Wang, LW AF Raczkowski, D Canning, A Wang, LW TI Thomas-Fermi charge mixing for obtaining self-consistency in density functional calculations SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE CALCULATIONS; TOTAL-ENERGY CALCULATIONS; SEMICONDUCTORS; CONVERGENCE; EFFICIENCY; SCHEME AB We present a method for charge mixing in self-consistent density functional calculations which uses the Thomas-Fermi-von Weizsacker equation to solve implicitly for the charge density response function to the potential. This approach has significant improvements over existing methods, particularly for inhomogeneous systems with large unit cells which commonly suffer from poor convergence due to charge sloshing. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. NR 18 TC 19 Z9 19 U1 1 U2 8 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 121101 DI 10.1103/PhysRevB.64.121101 PG 4 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400001 ER PT J AU Schneider, HC Chow, WW Koch, SW AF Schneider, HC Chow, WW Koch, SW TI Many-body effects in the gain spectra of highly excited quantum-dot lasers SO PHYSICAL REVIEW B LA English DT Article ID TIME-RESOLVED PHOTOLUMINESCENCE; RAPID CARRIER RELAXATION; ENERGY RELAXATION; PHONON BOTTLENECK; THRESHOLD CURRENT; AUGER PROCESSES; DYNAMICS; LUMINESCENCE; WAVELENGTH; STATES AB Optical gain spectra are computed for quantum dots under high excitation conditions. where there is a non-negligible two-dimensional carrier density surrounding the dots. Using a screened Hartree-Fock theory to describe the influence of the Coulomb interaction, we find different self-energy shifts for the dot and quantum-well transitions. Furthermore. in contrast to the result for quantum-well and bulk systems. the peak gain at the quantum-dot transition computed including Coulomb effects is reduced from its free carrier value. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Marburg, Dept Phys, D-35037 Marburg, Germany. Univ Marburg, Ctr Mat Sci, D-35037 Marburg, Germany. RP Schneider, HC (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Schneider, Hans Christian/B-9450-2009 OI Schneider, Hans Christian/0000-0001-7656-4919 NR 36 TC 71 Z9 71 U1 1 U2 12 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 11 AR 115315 DI 10.1103/PhysRevB.64.115315 PG 7 WC Physics, Condensed Matter SC Physics GA 474ZG UT WOS:000171136700079 ER PT J AU Shumway, J Williamson, AJ Zunger, A Passaseo, A DeGiorgi, M Cingolani, R Catalano, M Crozier, P AF Shumway, J Williamson, AJ Zunger, A Passaseo, A DeGiorgi, M Cingolani, R Catalano, M Crozier, P TI Electronic structure consequences of In/Ga composition variations in self-assembled InxGa1-xAs/GaAs alloy quantum dots SO PHYSICAL REVIEW B LA English DT Article ID OPTICAL-PROPERTIES; HOLE ALIGNMENT; STRAIN; GAAS; INTERDIFFUSION; STATES; BAND; NANOSTRUCTURES; LUMINESCENCE; SEGREGATION AB Provided that the shape, size, and composition profile of semiconductor-embedded quantum dots are given, theory is able to accurately calculate the excitonic transitions, including the effects of inhomogeneous strain, alloy fluctuations, electron-hole binding, and multiband and intervalley coupling. While experiment can accurately provide the spectroscopic signature of the excitonic transitions, accurate determination of the size, shape, and composition profile of such dots is still difficult. We show how one can arrive at a consistent picture of both the material and the electronic structure by interactive iteration between theory and experiment. Using high-resolution transmission electron microscopy, electron-energy-loss spectroscopy, and photoluminescence (PL) spectroscopy in conjunction with atomistic empirical pseudopotential calculations, we establish a model consistent with both the observed material structure and measured electronic/optical properties of a quantum dot sample. The structural model with best agreement between measured and predicted PL is a truncated cone with height 35 Angstrom, base diameter 200 Angstrom, and top diameter 160 Angstrom, having a nonuniform, peaked composition profile with average 60% In content. Next, we use our best structure to study the effect of varying (i) the amount of In in the dots, and (ii) the spatial distribution of In within the dots. We find that by either increasing the amount of In within the dot or by concentrating a given amount of In near the center of the dot, both electrons and holes become more strongly bound to the dot. A small change of In content from 50 to 60% causes an exciton redshift of about 70 meV. Changing the composition profile from a uniform In distribution to a centrally peaked distribution can redshift the exciton by an additional 20-40 meV. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Lecce, Dipartimento Ingn Innovaz, Inst CNR IME, I-73100 Lecce, Italy. Arizona State Univ, Ctr Solid State Sci, Tempe, AZ 85287 USA. RP Shumway, J (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Cingolani, Roberto/B-9191-2011; Zunger, Alex/A-6733-2013; Passaseo, Adriana/C-5136-2016 OI Passaseo, Adriana/0000-0002-1845-4073 NR 53 TC 69 Z9 69 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 125302 DI 10.1103/PhysRevB.64.125302 PG 12 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400063 ER PT J AU Woicik, JC Nelson, EJ Heskett, D Warner, J Berman, LE Karlin, BA Vartanyants, IA Hasan, MZ Kendelewicz, T Shen, ZX Pianetta, P AF Woicik, JC Nelson, EJ Heskett, D Warner, J Berman, LE Karlin, BA Vartanyants, IA Hasan, MZ Kendelewicz, T Shen, ZX Pianetta, P TI X-ray standing-wave investigations of valence electronic structure SO PHYSICAL REVIEW B LA English DT Article ID SURFACE-STRUCTURE DETERMINATION; PHOTOELECTRON-SPECTROSCOPY; PHOTOEMISSION SPECTRA; PARTIAL DENSITY; CROSS-SECTIONS; COOPER-MINIMUM; NIO; STATES; ALLOYS; DIFFRACTION AB We have examined the valence-electron emission from Cu, Ge, GaAs, InP, and NiO single crystals under the condition of strong x-ray Bragg reflection; i.e., in the presence of the spatially modulated x-ray standing-wave interference field that is produced by the superposition of the incident and reflected x-ray beams. These crystals span the entire metallic, covalent, and ionic range of solid-state bonding. It is demonstrated that the valence-electron emission is closely coupled to the atomic cores, even for electron states close to a metallic Fermi edge. Using the bond-orbital approximation, the x-ray standing-wave structure factor for valence-electron emission is derived in terms of the bond polarities and photoionization cross sections of the atoms within the crystalline unit cell and compared to experiment. Additionally, we demonstrated that by exploiting the spatial dependence of the electric-field intensity under Bragg condition, site specific valence electronic structure may be obtained. The technique is demonstrated for GaAs and NiO. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Rhode Isl, Dept Phys, Kingston, RI 02881 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Woicik, JC (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RI HASAN, M. Zahid/D-8237-2012 NR 60 TC 24 Z9 24 U1 1 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 125115 DI 10.1103/PhysRevB.64.125115 PG 15 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400038 ER PT J AU Xu, J Moxom, J Somieski, B White, CW Mills, AP Suzuki, R Ishibashi, S AF Xu, J Moxom, J Somieski, B White, CW Mills, AP Suzuki, R Ishibashi, S TI Positronic probe of vacancy defects on surfaces of Au nanoparticles embedded in MgO SO PHYSICAL REVIEW B LA English DT Article ID ANNIHILATION AB Clusters of four atomic vacancies were found in Au nanoparticle-embedded MgO by positron lifetime spectroscopy [Phys. Rev. Lett. 83, 4586 (1999)]. These clusters were also suggested to locate at the surface of Au nanoparticles by one-detector measurements of Doppler broadening of annihilation radiation. In this work we provide evidence, using two-detector coincidence experiments of Doppler broadening (2D-DBAR), to clarify that these vacancy clusters reside on the surfaces of Au nanoparticles. This work also demonstrates a method for identifying defects at nanomaterials interfaces: a combination of both positron lifetime spectroscopy, which tells the type of the defects, and 2D-DBAR measurements, which reveals chemical environment of the defects. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Electrotech Lab, Tsukuba, Ibaraki 305, Japan. RP Xu, J (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 14 TC 9 Z9 10 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 11 AR 113404 DI 10.1103/PhysRevB.64.113404 PG 4 WC Physics, Condensed Matter SC Physics GA 474ZG UT WOS:000171136700032 ER PT J AU Zhang, Y Mascarenhas, A Wang, LW AF Zhang, Y Mascarenhas, A Wang, LW TI Statistical aspects of electronic and structural properties in partially ordered semiconductor alloys SO PHYSICAL REVIEW B LA English DT Article ID LONG-RANGE-ORDER; ABSORPTION FINE-STRUCTURE; ATOMIC-SCALE STRUCTURE; PHOTOLUMINESCENCE AB We have investigated the statistical effects of spontaneous ordering on the electronic and structural properties of a semiconductor alloy as a function of order parameter using an empirical pseudopotential method in conjunction with a valence force field method in a supercell approach. The theoretical modeling yields valuable information on the statistical fluctuation of electronic properties, which includes the individual band edge as well as the band gap, for understanding the effects of ordering on various optical and transport measurements. The results on the average bond lengths and the statistical distributions of different types of bonds provide a guideline for the measurability of the effects of ordering in a partially ordered alloy in terms of the order parameter. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Berkeley, CA 94720 USA. RP Zhang, Y (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. EM yzhang@nrel.gov NR 23 TC 12 Z9 12 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 125207 DI 10.1103/PhysRevB.64.125207 PG 5 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400056 ER PT J AU Zudov, MA Kono, J Mitchell, AP Chin, AH AF Zudov, MA Kono, J Mitchell, AP Chin, AH TI Time-resolved, nonperturbative, and off-resonance generation of optical terahertz sidebands from bulk GaAs SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM-WELLS; SIDE-BAND; ELECTROABSORPTION AB We have investigated terahertz (THz) sideband generation from bulk GaAs using intense pulses of coherent THz (or far-infrared) radiation from a free electron laser. In contrast to previous studies, sidebands appeared inside the band gap and therefore were not resonantly enhanced from real states. Also, using picosecond pulses and changing the temporal overlap between the THz and near-infrared pulses allowed us to monitor the evolution of the THz sidebands directly in the time domain; this suggests a convenient method for characterizing THz pulses using a conventional Si photodetector. In addition to an expected second-order sideband, we detected a first-order sideband, which has previously been observed only in an asymmetrically coupled double quantum well system where the inversion symmetry was intentionally broken. Finally, the THz power dependence clearly revealed a deviation from perturbative behavior, indicating the entrance into the strong-field regime. C1 Rice Univ, Dept Elect & Comp Engn, Houston, TX 77005 USA. Stanford Univ, WW Hansen Expt Phys Lab, Stanford, CA 94305 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Kono, J (reprint author), Rice Univ, Dept Elect & Comp Engn, Houston, TX 77005 USA. EM maz@physics.utah.edu; kono@rice.edu RI Zudov, Michael/A-3013-2008 NR 14 TC 18 Z9 19 U1 1 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD SEP 15 PY 2001 VL 64 IS 12 AR 121204 DI 10.1103/PhysRevB.64.121204 PG 4 WC Physics, Condensed Matter SC Physics GA 476TG UT WOS:000171244400009 ER PT J AU Antunes, ND Bettencourt, LMA Yates, A AF Antunes, ND Bettencourt, LMA Yates, A TI Predicting the critical density of topological defects in O(N) scalar field theories SO PHYSICAL REVIEW D LA English DT Article ID COSMIC-STRING FORMATION; PHASE-TRANSITIONS; SUPERFLUID HE-3; VORTEX STRINGS; HELIUM AB O(N) symmetric lambda phi (4) field theories describe many critical phenomena in the laboratory and in the early Universe. Given N and D less than or equal to 3, the spatial dimension, these models exhibit topological defect classical solutions that in some cases fully determine their critical behavior. For N = 2 and D = 3, it has been observed that the defect density is seemingly a universal quantity at T-c. We prove this conjecture and show how to predict its value based on the universal critical exponents of the field theory. Analogously, for general N and D we predict the universal critical densities of domain walls and monopoles, for which no detailed thermodynamic study exists, to our knowledge. Remarkably this procedure can be inverted, producing an algorithm for generating typical defect networks at criticality, in contrast with the usual procedure [Vachaspati and Vilenkin, Phys. Rev. D 30, 2036 (1984)], which applies only in the unphysical limit of infinite temperature. C1 Univ Sussex, Ctr Theoret Phys, Brighton BN1 9QJ, E Sussex, England. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. UCL, Ctr Nonlinear Dynam & Its Applicat, London WC1E 6BT, England. RP Univ Sussex, Ctr Theoret Phys, Brighton BN1 9QJ, E Sussex, England. NR 19 TC 3 Z9 3 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD SEP 15 PY 2001 VL 64 IS 6 AR 065020 DI 10.1103/PhysRevD.64.065020 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 472HN UT WOS:000170978200064 ER PT J AU Chung, DJH Everett, L Davoudiasl, H AF Chung, DJH Everett, L Davoudiasl, H TI Experimental probes of the Randall-Sundrum infinite extra dimension SO PHYSICAL REVIEW D LA English DT Article ID LARGE COMPACT DIMENSIONS; SCALE QUANTUM-GRAVITY; COLLIDER SIGNATURES; BRANE WORLD; TEV; PHENOMENOLOGY; CONSTRAINTS; HIERARCHY; MODEL; BULK AB The phenomenological possibilities of the Randall-Sundrum noncompact extra dimension scenario with the AdS horizon increased to approximately a millimeter length, corresponding to an effective brane tension of (Tev)(4), are investigated. The corrections to the Newtonian potential are found to be the only observationally accessible probe of this scenario, as previously suggested in the literature. In particular, the presence of the continuum of Kaluza-Klein modes does not lead to any observable collider signatures. The extent to which experimental tests of Newtonian gravity can distinguish this scenario from the scenario of Arkani-Hamed, Dimopoulos, and Dvali, with 1- and 2-mm size extra dimensions, is explicitly demonstrated. C1 Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Univ Michigan, Randall Lab Phys, Ann Arbor, MI 48109 USA. EM djchung@umich.edu; leverett@feynman.physics.lsa.umich.edu; hooman@slac.stanford.edu NR 56 TC 22 Z9 22 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 SEP 15 PY 2001 VL 64 IS 6 AR 065002 DI 10.1103/PhysRevD.64.065002 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 472HN UT WOS:000170978200047 ER PT J AU de Oliveira, HP Joras, SE AF de Oliveira, HP Joras, SE TI Perturbations in warm inflation SO PHYSICAL REVIEW D LA English DT Article ID COSMOLOGICAL PERTURBATIONS; DENSITY PERTURBATIONS; THERMAL DISSIPATION; SCENARIO; SPECTRA; SCALAR; MODELS AB Warm inflation is an interesting possibility to describe the early universe, whose basic feature is the absence, at least in principle, of a preheating or reheating phase. Here we analyze the dynamics of warm inflation generalizing the usual slow-roll parameters that are useful for characterizing the inflationary phase. We study the evolution of entropy and adiabatic perturbations, where the main result is that for a very small amount of dissipation the entropy perturbations can be neglected and the purely adiabatic perturbations will be responsible for the primordial spectrum of inhomogeneities. Taking into account the Cosmic Background Explorer Differential Microwave Radiometer data of the cosmic microwave background anisotropy as well as the fact that the interval of inflation for which the scales of astrophysical interest cross outside the Hubble radius is about 50 e-folds before the end of inflation, we could estimate the magnitude of the dissipation term. It is also possible to show that at the end of inflation the universe is hot enough to provide a smooth transition to the radiation era. C1 Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. Univ Estado Rio de Janeiro, Inst Fis, Dept Fis Teor, BR-20550013 Rio De Janeiro, Brazil. Brown Univ, Dept Phys, Providence, RI 02912 USA. RP de Oliveira, HP (reprint author), Fermilab Natl Accelerator Lab, NASA, Fermilab Astrophys Ctr, POB 500, Batavia, IL 60510 USA. EM henrique@fnal.gov; joras@het.brown.edu RI Joras, Sergio/M-9230-2014 NR 22 TC 36 Z9 36 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 SEP 15 PY 2001 VL 64 IS 6 AR 063513 DI 10.1103/PhysRevD.64.063513 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 472HN UT WOS:000170978200019 ER PT J AU Kleban, M Lawrence, A Shenker, S AF Kleban, M Lawrence, A Shenker, S TI Closed strings from nothing SO PHYSICAL REVIEW D LA English DT Article ID SUPERSTRING FIELD-THEORY; D-BRANES; TACHYON CONDENSATION; DESCENT RELATIONS; MODEL; GEOMETRY; VACUUM AB We study the physics of open strings in bosonic and type-II string theories in the presence of unstable D-branes. When the potential energy of the open string tachyon is at its minimum. Sen has argued that only closed strings remain in the perturbative spectrum. We explore the scenario of Yi and of Bergman, Hori. and Yi. who argue that the open string degrees of freedom are strongly coupled and disappear through confinement. We discuss arguments using open string field theory and world sheet boundary renormalization group flows, which seem to indicate otherwise. We then describe a solitonic excitation of the open string tachyon and gauge field with the charge and tension of a fundamental closed string. This requires a double scaling limit where the tachyon is taken to its minimal value and the electric field is taken to its maximum value. The resulting flux tube has an unconstrained spatial profiled and for large fundamental string charge it appears to have light, weakly coupled open strings existing in the core. We argue that the flux tube acquires a size of order alpha' through sigma model and string coupling effects, and that confinement effects make the light degrees of freedom heavy and strongly interacting. C1 Stanford Univ, Dept Phys, Stanford, CA 94305 USA. Stanford Linear Accelerator Ctr, Theory Grp, Stanford, CA 94309 USA. RP Kleban, M (reprint author), Stanford Univ, Dept Phys, Stanford, CA 94305 USA. OI Kleban, Matthew/0000-0002-1889-2487; Lawrence, Albion/0000-0003-4116-045X NR 71 TC 23 Z9 23 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD SEP 15 PY 2001 VL 64 IS 6 AR 066002 DI 10.1103/PhysRevD.64.066002 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 472HN UT WOS:000170978200073 ER PT J AU Salian, U Srinivas, S Jellinek, J AF Salian, U Srinivas, S Jellinek, J TI Theoretical investigations of the interaction of silver trimer with ethylene molecule SO CHEMICAL PHYSICS LETTERS LA English DT Article ID EFFECTIVE CORE POTENTIALS; DENSITY-FUNCTIONAL CALCULATIONS; BASIS-SETS; CLUSTERS; ENERGY; AMMONIA; COPPER; ATOMS; SPECTROSCOPY; DERIVATIVES AB The interaction of silver trimer with ethylene molecule is investigated within the density functional framework using the Becke exchange and Perdew-Wang (91) correlation functionals. Structural forms and electronic properties (binding energy and ionization potential) of the cluster-molecule complex are determined. Ag(3)-C(2)H(4) forms two isomers. In agreement with the experimental results, the computed ionization potential of the more stable isomer is lower than that of the bare Ag(3) cluster. (C) 2001 Published by Elsevier Science B.V. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Jellinek, J (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM jellinek@anlchm.chm.anl.gov NR 35 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD SEP 14 PY 2001 VL 345 IS 3-4 BP 312 EP 318 DI 10.1016/S0009-2614(01)00881-8 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 479LD UT WOS:000171405100017 ER PT J AU Yang, M Agarwal, R Fleming, GR AF Yang, M Agarwal, R Fleming, GR TI The mechanism of energy transfer in the antenna of photosynthetic purple bacteria SO JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY LA English DT Article DE purple bacteria; antenna; photosynthesis ID LIGHT-HARVESTING COMPLEX; ECHO PEAK SHIFT; RHODOBACTER-SPHAEROIDES R-26; NONLINEAR-OPTICAL RESPONSE; POLAR SOLVATION DYNAMICS; STIMULATED PHOTON-ECHO; RHODOPSEUDOMONAS-ACIDOPHILA; CRYSTAL-STRUCTURE; LH2 ANTENNA; EXCITON DELOCALIZATION AB The mechanism of energy transfer in the antenna system of purple bacteria is investigated by combination of photon echo spectroscopy and disordered exciton theory. In the B800 component of light harvesting complex 2 (LH2), a picture of incoherent hopping between monomers provides an excellent description of the photon echo data recorded as a function of excitation wavelength. In the B850 pigments of LH2, and to a somewhat greater extent in the B875 pigments of light harvesting complex 1 (LH1), the excitation is delocalized over several pigments. The observed dynamics correspond to relaxation between exciton states as a result of exciton-phonon coupling. Nonetheless, a picture of "hopping" between small groups of molecules provides a crude description of the motion of the excitation in B850, and B875. The electronic coupling required to simulate the experimental absorption spectrum and photon echo data is larger in LH1 than in LH2 (B850). (C) 2001 Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Phys Biosci Div, Berkeley, CA 94720 USA. RP Yang, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Phys Biosci Div, Berkeley, CA 94720 USA. OI Yang, Mino/0000-0001-9504-0280 NR 83 TC 57 Z9 59 U1 2 U2 13 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 1010-6030 J9 J PHOTOCH PHOTOBIO A JI J. Photochem. Photobiol. A-Chem. PD SEP 14 PY 2001 VL 142 IS 2-3 BP 107 EP 119 DI 10.1016/S1010-6030(01)00504-4 PG 13 WC Chemistry, Physical SC Chemistry GA 475NH UT WOS:000171170300003 ER PT J AU Rumbles, G Selmarten, DC Ellingson, RJ Blackburn, JL Yu, PR Smith, BB Micic, OI Nozik, AJ AF Rumbles, G Selmarten, DC Ellingson, RJ Blackburn, JL Yu, PR Smith, BB Micic, OI Nozik, AJ TI Anomalies in the linear absorption, transient absorption, photoluminescence and photoluminescence excitation spectroscopies of colloidal InP quantum dots SO JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY LA English DT Article DE linear absorption; transient absorption; InP quantum dots; photoluminescence ID SEMICONDUCTOR NANOCRYSTALS; DYNAMICS; EMISSION; TRANSITIONS; ASSIGNMENT; EXCITON AB We report photoluminescence (PL), linear absorption and femtosecond, transient bleaching spectra for a colloidal solution of indium phosphide (InP) quantum dots (QDs) at ambient temperature. The PL quantum yield is shown to depend significantly upon the excitation wavelength and the PL excitation spectrum deviates markedly from the absorption spectrum. The cooling of electrons and holes to the lowest energy excited state is determined, by transient bleaching spectroscopy, to occur with an efficiency that is independent of the excitation wavelength. These results are discussed in terms of a threshold for a non-radiative decay process that resides above the bandgap and a PL quantum yield that depends upon the size of QD. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. RP Rumbles, G (reprint author), Natl Renewable Energy Lab, Ctr Basic Sci, Golden, CO 80401 USA. RI Blackburn, Jeffrey/D-7344-2012; Ellingson, Randy/H-3424-2013; Nozik, Arthur/A-1481-2012; Nozik, Arthur/P-2641-2016; OI Rumbles, Garry/0000-0003-0776-1462 NR 32 TC 18 Z9 18 U1 2 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 1010-6030 J9 J PHOTOCH PHOTOBIO A JI J. Photochem. Photobiol. A-Chem. PD SEP 14 PY 2001 VL 142 IS 2-3 BP 187 EP 195 DI 10.1016/S1010-6030(01)00513-5 PG 9 WC Chemistry, Physical SC Chemistry GA 475NH UT WOS:000171170300012 ER PT J AU Papenbrock, T Seligman, TH AF Papenbrock, T Seligman, TH TI Invariant manifolds and collective coordinates SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID CHAOTIC SYSTEMS; BODY SYSTEMS; NUCLEI; SYNCHRONIZATION; QUANTIZATION; COEXISTENCE; DYNAMICS; BILLIARD; ORBITS; STATES AB We introduce suitable coordinate systems for interacting many-body systems with invariant manifolds. These are Cartesian in coordinate and momentum space and chosen such that several components are identically zero for motion on the invariant manifold. In this sense these coordinates are collective. We make a connection to Zickendraht's collective coordinates and present certain configurations of few-body systems where rotations and vibrations decouple from single-particle motion. These configurations do not depend on details of the interaction. C1 Ctr Int Ciencias, Cuernavaca, Morelos, Mexico. Univ Washington, Inst Nucl Theory, Seattle, WA 98195 USA. Univ Nacl Autonoma Mexico, Ctr Ciencias Fis, Cuernavaca 62191, Morelos, Mexico. RP Papenbrock, T (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. OI Papenbrock, Thomas/0000-0001-8733-2849 NR 27 TC 2 Z9 2 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD SEP 14 PY 2001 VL 34 IS 36 BP 7423 EP 7430 DI 10.1088/0305-4470/34/36/321 PG 8 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 482VB UT WOS:000171597000023 ER PT J AU Reinhold, CO Yoshida, S Burgdorfer, J Tannian, BE Stokely, CL Dunning, FB AF Reinhold, CO Yoshida, S Burgdorfer, J Tannian, BE Stokely, CL Dunning, FB TI Designing Rydberg wavepackets using trains of half-cycle pulses SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID WAVE-PACKETS; DYNAMICAL STABILIZATION; ATOM AB A technique for generating Rydberg wavepackets in preferred target states is demonstrated that exploits the mixed phase space structure of the periodically 'kicked' Rydberg atom. Experimental data and classical simulations for very-high-n Rydberg atoms are presented that show that application of a train of equispaced, unidirectional half-cycle pulses can lead to localization of the final wavepacket in classical stable islands. The product wavepackets are examined using a delayed half-cycle probe pulse. It is demonstrated that the motion of the wavepackets is either quasiperiodic or random depending on whether or not the initial state of the atom overlaps a stable island. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Vienna Univ Technol, Inst Theoret Phys, A-1040 Vienna, Austria. Rice Univ, Rice Quantum Inst, Houston, TX 77005 USA. Rice Univ, Dept Phys & Astron, Houston, TX 77005 USA. RP Reinhold, CO (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. OI Reinhold, Carlos/0000-0003-0100-4962 NR 11 TC 15 Z9 16 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD SEP 14 PY 2001 VL 34 IS 17 BP L551 EP L558 DI 10.1088/0953-4075/34/17/101 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 482KA UT WOS:000171574300001 ER PT J AU Smith, ACH Bannister, ME Chung, YS Djuric, N Dunn, GH Neau, A Popovic, D Stepanovic, M Wallbank, B AF Smith, ACH Bannister, ME Chung, YS Djuric, N Dunn, GH Neau, A Popovic, D Stepanovic, M Wallbank, B TI Excitation of He(+) to the 2 (2)S and 2 (2)P states by electron impact SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID CLOSE-COUPLING CALCULATIONS; ENERGY-LOSS TECHNIQUE; CROSS-SECTIONS; N=3 LEVEL; 2S STATE; SCATTERING; BEAMS; IONS; AUTOIONIZATION; TRANSITIONS AB The first absolute measurement of the cross section for excitation of a hydrogenlike ion is reported. The combined cross section for electron impact excitation of ground state He(+) to the 2 (2)S and 2 (2)P excited states has been measured in the near-threshold region from 40.08 to 41.95 eV using the JILA/ORNL merged electron-ion beams energy-loss technique. The threshold step in the cross section is measured as (8.46 +/-1.52) x 10(-18) cm(2) at 90% confidence level of total uncertainty, which is approximately 20% larger than values calculated using close-coupling and variational methods. This contrasts with the longstanding disparity of nearly a factor of two between theory and normalized experiment fur excitation to the 2 (2)S state. C1 UCL, Dept Phys & Astron, London WC1E 6BT, England. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Chungnam Natl Univ, Dept Phys, Taejon 305764, South Korea. Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. Univ Colorado, Natl Inst Stand & Technol, Boulder, CO 80309 USA. Univ Stockholm, Dept Phys, S-11385 Stockholm, Sweden. St Francis Xavier Univ, Antigonish, NS B2G 2W5, Canada. RP Smith, ACH (reprint author), UCL, Dept Phys & Astron, Mortimer St, London WC1E 6BT, England. EM banniste@mail.phy.ornl.gov NR 20 TC 7 Z9 7 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD SEP 14 PY 2001 VL 34 IS 17 BP L571 EP L577 DI 10.1088/0953-4075/34/17/104 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 482KA UT WOS:000171574300004 ER PT J AU Wolfrum, E Allen, AM Al'Miev, I Barbee, TW Burnett, PDS Djaoui, A Iglesias, C Kalantar, DH Lee, RW Keenan, R Key, MH Lewis, CLS Machacek, AM Remington, BA Rose, SJ O'Rourke, R Wark, JS AF Wolfrum, E Allen, AM Al'Miev, I Barbee, TW Burnett, PDS Djaoui, A Iglesias, C Kalantar, DH Lee, RW Keenan, R Key, MH Lewis, CLS Machacek, AM Remington, BA Rose, SJ O'Rourke, R Wark, JS TI Measurements of the XUV mass absorption coefficient of an overdense liquid metal SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID X-RAY LASER; ELECTRICAL-CONDUCTIVITY; ALUMINUM PLASMAS; SHOCK HUGONIOT; RESISTIVITY; IONIZATION; 106-K; STATE AB The increase in the XUV mass absorption coefficient of liquid aluminium, produced by high-power-laser shock-compression, is measured using XUV laser radiography. At a photon energy of 63 eV a change in the mass absorption coefficient by up to a factor of similar to2.2 is determined at densities close to twice that of solid and electron temperatures of the order of 1 eV. Comparison with hydrodynamic simulations indicate that the absorption coefficient scales with density as rho (1.3 +/-0.2). C1 Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Queens Univ Belfast, Sch Math & Phys, Belfast BT7 1NN, Antrim, North Ireland. RP Wolfrum, E (reprint author), Max Planck Inst Plasma Phys, Boltzmannstr 2, D-85748 Garching, Germany. NR 22 TC 6 Z9 6 U1 1 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD SEP 14 PY 2001 VL 34 IS 17 BP L565 EP L570 DI 10.1088/0953-4075/34/17/103 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 482KA UT WOS:000171574300003 ER PT J AU Viola, L Fortunato, EM Pravia, MA Knill, E Laflamme, R Cory, DG AF Viola, L Fortunato, EM Pravia, MA Knill, E Laflamme, R Cory, DG TI Experimental realization of noiseless subsystems for quantum information processing SO SCIENCE LA English DT Article ID DECOHERENCE-FREE SUBSPACES; ERROR-CORRECTION; ENTANGLEMENT; COMPUTATION; CODES AB We demonstrate the protection of one bit of quantum information against all collective noise in three nuclear spins. Because no subspace of states offers this protection, the quantum bit was encoded in a proper noiseless subsystem. We therefore realize a general and efficient method for protecting quantum information. Robustness was verified for a full set of noise operators that do not distinguish the spins. Verification relied on the most complete exploration of engineered decoherence to date. The achieved fidelities show improved information storage for a large, noncommutative set of errors. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. MIT, Dept Nucl Engn, Cambridge, MA 02139 USA. RP Viola, L (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 30 TC 159 Z9 162 U1 3 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 SEP 14 PY 2001 VL 293 IS 5537 BP 2059 EP 2063 DI 10.1126/science.1064460 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 473FB UT WOS:000171028700066 PM 11557885 ER PT J AU Lorenz, KT Chandler, DW Barr, JW Chen, WW Barnes, GL Cline, JI AF Lorenz, KT Chandler, DW Barr, JW Chen, WW Barnes, GL Cline, JI TI Direct measurement of the preferred sense of NO rotation after collision with argon SO SCIENCE LA English DT Article ID DIFFERENTIAL CROSS-SECTIONS; INELASTIC-SCATTERING; ANGULAR-DISTRIBUTIONS; CHEMICAL-REACTIONS; STEREODYNAMICS; POLARIZATION; DYNAMICS; SYSTEM; BEAMS AB The preferred sense of product molecule rotation (clockwise or counterclockwise) in a bimolecular collision system has been measured. Rotationally inelastic collisions of nitric oxide (NO) molecules with Ar atoms were studied by combining crossed molecular beams, circularly polarized resonant multiphoton ionization probing, and velocity-mapped ion imaging detection. The observed sense of NO product rotation varies with deflection angle and is a strong function of the NO final rotational state. The largest preferences for sense of rotation are observed at the highest kinematically allowed product rotational states; for tower rotational states, the variation with deflection angle becomes oscillatory. Quantum calculations on the most recently reported NO-Ar potential give good agreement with the observed oscillation patterns in the sense of rotation. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94550 USA. Univ Nevada, Dept Chem, Reno, NV 89557 USA. Univ Nevada, Chem Phys Program, Reno, NV 89557 USA. RP Lorenz, KT (reprint author), Sandia Natl Labs, Combust Res Facil, POB 969, Livermore, CA 94550 USA. RI Barnes, George/A-3552-2011; Barnes, George/D-6951-2012 NR 25 TC 85 Z9 90 U1 2 U2 21 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 14 PY 2001 VL 293 IS 5537 BP 2063 EP 2066 DI 10.1126/science.1062754 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 473FB UT WOS:000171028700067 PM 11557886 ER PT J AU Kim, SK Lund, J Kiraly, M Duke, K Jiang, M Stuart, JM Eizinger, A Wylie, BN Davidson, GS AF Kim, SK Lund, J Kiraly, M Duke, K Jiang, M Stuart, JM Eizinger, A Wylie, BN Davidson, GS TI A gene expression map for Caenorhabditis elegans SO SCIENCE LA English DT Article ID FUNCTIONAL GENOMIC ANALYSIS; C-ELEGANS; DNA MICROARRAY; PROTEINS; PATTERNS; RNAI; ORGANIZATION; MUTATIONS; DISCOVERY; PROFILES AB We have assembled data from Caenorhabditis elegans DNA microarray experiments involving many growth conditions, developmental stages, and varieties of mutants. Co-regulated genes were grouped together and visualized in a three-dimensional expression map that displays correlations of gene expression profiles as distances in two dimensions and gene density in the third dimension. The gene expression map can be used as a gene discovery toot to identify genes that are co-regulated with known sets of genes (such as heat shock, growth control genes, germ line genes, and so forth) or to uncover previously unknown genetic functions (such as genomic instability in mates and sperm caused by specific transposons). C1 Stanford Univ, Sch Med, Dept Dev Biol & Genet, Stanford, CA 94305 USA. Stanford Med Informat, Stanford, CA 94305 USA. Sandia Natl Labs, Computat Comp & Math Ctr, Albuquerque, NM 87185 USA. RP Stanford Univ, Sch Med, Dept Dev Biol & Genet, Stanford, CA 94305 USA. EM kim@cmgm.stanford.edu OI Lund, Jim/0000-0002-1437-8448 NR 31 TC 478 Z9 491 U1 2 U2 19 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 SEP 14 PY 2001 VL 293 IS 5537 BP 2087 EP 2092 DI 10.1126/science.1061603 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 473FB UT WOS:000171028700074 PM 11557892 ER PT J AU Marcy, TP Diaz, RR Heard, D Leone, SR Harding, LB Klippenstein, SJ AF Marcy, TP Diaz, RR Heard, D Leone, SR Harding, LB Klippenstein, SJ TI Theoretical and experimental investigation of the dynamics of the production of CO from the CH3+O and CD3+O reactions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; RESOLVED FTIR EMISSION; GAUSSIAN-BASIS SETS; WAVE-FUNCTIONS; ATOMS; RADICALS AB Combined experimental and theoretical investigations of the title reactions are presented. Time-resolved Fourier transform infrared (FTIR) emission studies of CO (v = 1) produced from the CH3 + O and CD3 + O reactions show that there is approximately a one-third reduction in the branching to the CO channel upon deuteration of the methyl radical. Direct dynamics, classical trajectory calculations using a B3LYP potential surface, confirm the existence of the CO producing channel. The calculations show that the CO comes from the decomposition of HCO produced by the elimination of H-2 from highly vibrationally excited methoxy radicals. Scans of the potential surface reveal no saddle point for the direct elimination of H-2 from methoxy. The mininum-energy path for this elimination is a stepwise process involving first a CH bond cleavage, forming H + H2CO, followed by an abstraction, forming H-2 + HCO. However, at the high internal energies produced in the initial O + CH3 addition, trajectories for the direct elimination of H-2 from methoxy are observed. The predicted branching ratio between the CO and H2CO channels is in good agreement with previous room temperature measurements, and there is predicted to be little temperature dependence to it. The observed reduction in the branching to the CO channel upon deuteration is also well reproduced in the calculations. C1 Univ Colorado, Dept Chem & Biochem, Boulder, CO 80309 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. Univ Leeds, Sch Chem, Leeds LS2 9JT, W Yorkshire, England. RI Diaz-Morales, Robert/D-8733-2013; OI Diaz-Morales, Robert/0000-0003-1565-0412; Klippenstein, Stephen/0000-0001-6297-9187; Heard, Dwayne/0000-0002-0357-6238 NR 23 TC 81 Z9 81 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD SEP 13 PY 2001 VL 105 IS 36 BP 8361 EP 8369 DI 10.1021/jp010961f PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 472RG UT WOS:000170998300013 ER PT J AU Zelicoff, AP AF Zelicoff, AP TI Enthusiasm ran ahead of discoveries still to come SO NATURE LA English DT Letter C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Zelicoff, AP (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD SEP 13 PY 2001 VL 413 IS 6852 BP 108 EP 108 DI 10.1038/35093275 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 471FU UT WOS:000170918800022 PM 11557951 ER PT J AU Daum, KA Atkinson, DA Ewing, RG AF Daum, KA Atkinson, DA Ewing, RG TI Formation of halide reactant ions and effects of excess reagent chemical on the ionization of TNT in ion mobility spectrometry SO TALANTA LA English DT Article DE ion mobility spectrometry; halide reactant ions ID GAS-PHASE; ATMOSPHERIC-PRESSURE; CHLORIDE-ION; FRAGMENTATION PATHWAYS; PLASMA CHROMATOGRAPHY; MASS-SPECTROMETRY; FALP TECHNIQUE; ELECTRONS; 2,4,6-TRINITROTOLUENE; COEFFICIENTS AB The efficiency of chloride reactant ion formation, when chlorinated hydrocarbon reagent chemicals were added to the ionization region of an ion mobility spectrometer, corresponded to the electron attachment rate constant of the chemical. The chemicals investigated here included chloromethane, dichlormethane, trichloromethane, tetrachloromethane and chlorobenzene, with tetrachloromethane producing the greatest amount of chloride reactant ions for the amount of chemical added. Reagent chemicals with smaller electron attachment rate constants required the addition of more chemical to reach functional reactant ion levels. The excess neutral reagent molecules clustered to the chloride reactant ions and reduced the effectiveness of abstracting a proton from 2,4,6-trinitrotoluene (TNT). The effect of clustering was different for each chemical. Tetrachloromethane, which had the least exothermic clustering reaction, had the most effective production of the (TNT-H)(-) product ion per mole of reagent chemical. Bromide and iodide ions were also investigated as potential reactant ions. Bromide was found to effectively produce the proton abstracted (TNT-H)(-) ion. Iodide, however, was not a strong enough base to form (TNT-H)(-) from TNT. There was no apparent transfer of an electron to TNT by chloride, bromide or iodide. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Idaho Natl Engn & Environm Lab, Dept Chem, Idaho Falls, ID 83415 USA. RP Daum, KA (reprint author), Idaho Natl Engn & Environm Lab, Dept Chem, Idaho Falls, ID 83415 USA. NR 37 TC 25 Z9 25 U1 0 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-9140 J9 TALANTA JI Talanta PD SEP 13 PY 2001 VL 55 IS 3 BP 491 EP 500 DI 10.1016/S0039-9140(01)00453-2 PG 10 WC Chemistry, Analytical SC Chemistry GA 479RZ UT WOS:000171418500007 PM 18968394 ER PT J AU Huynh, MHV Lasker, JM Wetzler, M Mort, B Szczepura, LF Witham, LM Cintron, JM Marschilok, AC Ackerman, LJ Castellano, RK Jameson, DL Churchill, MR Jircitano, AJ Takeuchi, KJ AF Huynh, MHV Lasker, JM Wetzler, M Mort, B Szczepura, LF Witham, LM Cintron, JM Marschilok, AC Ackerman, LJ Castellano, RK Jameson, DL Churchill, MR Jircitano, AJ Takeuchi, KJ TI Remarkable spectator ligand effect on the rate constant of ligand substitution of (aqua)ruthenium(II) complexes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID RAY CRYSTAL-STRUCTURE; COORDINATION CHEMISTRY; RUTHENIUM COMPLEXES; PLATINUM(II); MONONUCLEAR; DINUCLEAR; ADDUCTS; CIS AB The influence of two different di(I-pyrazolyl)alkane ligands on the rate constant of aqua ligand substitution of ruthenium(II) complexes with the formula [Ru(H2O)(L-2)(tpmm)](2+) (L-2 = di(I-pyrazolyl)methane (DPMet) or 2,2-di(I-pyrazolyl)propane (DPPro)) was investigated. A 9.4 x 10(5)-fold increase in the rate constant of ligand substitution at pH = 6.86 was observed when DPMet was replaced with DPPro. This remarkable increase was unexpected, considering that these bidentate ligands appear quite similar. To help lend insight into this dramatic spectator ligand effect, the activation parameters for the ligand substitution reactions were determined, and single-crystal X-ray data were collected on the structurally analogous (chloro)ruthenium(II) complexes, [Ru(Cl)(L-2)(tpmm)](+). These results are discussed in the context of a heteroscorpionate effect exerted by the DPPro ligand. C1 SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA. Gettysburg Coll, Dept Chem, Gettysburg, PA 17325 USA. Illinois State Univ, Dept Chem, Normal, IL 61790 USA. Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Huynh, MHV (reprint author), SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA. RI Castellano, Ronald/C-5082-2012; Marschilok, Amy/D-1821-2014; OI Castellano, Ronald/0000-0003-4322-9932 NR 26 TC 12 Z9 12 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 12 PY 2001 VL 123 IS 36 BP 8780 EP 8784 DI 10.1021/ja0041977 PG 5 WC Chemistry, Multidisciplinary SC Chemistry GA 471JC UT WOS:000170925400016 PM 11535083 ER PT J AU Kuznetsov, AE Boldyrev, AI Li, X Wang, LS AF Kuznetsov, AE Boldyrev, AI Li, X Wang, LS TI On the aromaticity of square planar Ga-4(2-) and In-4(2-) in gaseous NaGa4- and NaIn4- clusters SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID EFFECTIVE CORE POTENTIALS; COMPACT EFFECTIVE POTENTIALS; MOLECULAR-ORBITAL METHODS; GAUSSIAN-BASIS SETS; EXPONENT BASIS-SETS; PHOTOELECTRON-SPECTROSCOPY; GREEN-FUNCTION; ATOMS; EFFICIENT; ANIONS AB We investigated the electronic structure and chemical bonding of two bimetallic clusters NaGa4- and NaIn4-. Photoelectron spectra of the anions were obtained and compared with ab initio calculations. We found that the ground state of the two anions contains a square planar dianion interacting with a Na+ cation. The Ga-4(2-) and In-4(2-) dianions both possess two delocalized pi electrons and are considered to be aromatic, similar to that recently found in Al-4(2-). Using calculations for a model compound, we showed that a recently synthesized Ga-4-organometallic compound also contains an aromatic -Ga-4(2-)- unit, analogous to the gaseous clusters. C1 Utah State Univ, Dept Chem & Biochem, Logan, UT 84322 USA. Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Kuznetsov, AE (reprint author), Utah State Univ, Dept Chem & Biochem, Logan, UT 84322 USA. RI Kuznetsov, Aleksey/F-1345-2010; Boldyrev, Alexander/C-5940-2009; Kuznetsov, Aleksey/E-5099-2015 OI Boldyrev, Alexander/0000-0002-8277-3669; NR 49 TC 185 Z9 189 U1 2 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 12 PY 2001 VL 123 IS 36 BP 8825 EP 8831 DI 10.1021/ja0106117 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA 471JC UT WOS:000170925400022 PM 11535089 ER PT J AU Lee, L Wang, JX Adzic, RR Robinson, IK Gewirth, AA AF Lee, L Wang, JX Adzic, RR Robinson, IK Gewirth, AA TI Adsorption configuration and local ordering of silicotungstate anions on Ag(100) electrode surfaces SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; ABSORPTION FINE-STRUCTURE; UNDERPOTENTIALLY DEPOSITED SILVER; X-RAY; MONOLAYERS; HETEROPOLYANION; DIFFRACTION; INTERFACE; GRAPHITE; AG(110) AB X-ray reflectivity, cyclic voltammetry, and scanning tunneling microscopy (STM) are used to examine the structure of alpha -SiW12O44- or silicotungstic acid (STA) adsorbed on Ag(100) in acid solution. The voltammetry shows that STA passivates the Ag surface relative to electron transfer to a solution redox species. STM images reveal the formation of a series of lattice structures, one of which can be associated with a commensurate (root 13 x root 13)R33.69 degrees structural model. X-ray reflectivity measurements show uniquely that STA orients with its four-fold axis perpendicular to the Ag(100) surface and that the center of the STA molecule is 4.90 Angstrom above the top laver of the Ag substrate. Analysis of bond lengths leads to a footprint of STA on Ag(100), in which the four terminal O atoms are located near the hollow sites and have a Ag-O bond length of 2.06 Angstrom. This bond length is consistent with a strong covalent interaction between STA and the Ag surface. C1 Brookhaven Natl Lab, Dept Appl Sci, Div Mat & Chem Sci, Upton, NY 11973 USA. Univ Illinois, Dept Chem, Dept Phys, Urbana, IL 61801 USA. Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA. RP Gewirth, AA (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Div Mat & Chem Sci, Upton, NY 11973 USA. RI Wang, Jia/B-6346-2011 NR 37 TC 27 Z9 27 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 12 PY 2001 VL 123 IS 36 BP 8838 EP 8843 DI 10.1021/ja0161352 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA 471JC UT WOS:000170925400024 PM 11535091 ER PT J AU Yin, J Mundorff, EC Yang, PL Wendt, KU Hanway, D Stevens, RC Schultz, PG AF Yin, J Mundorff, EC Yang, PL Wendt, KU Hanway, D Stevens, RC Schultz, PG TI A comparative analysis of the immunological evolution of antibody 28B4 SO BIOCHEMISTRY LA English DT Article ID SOMATIC HYPERMUTATION; CATALYTIC ANTIBODIES; MAXIMUM-LIKELIHOOD; BINDING; OXYGENATION; GENES; MICE; AUTOANTIBODY; REFINEMENT; MATURATION AB In an effort to gain greater insight into the evolution of the redox active, catalytic antibody 28B4, the germline genes used by the mouse to generate this antibody were cloned and expressed, and the X-ray crystal structures of the unliganded and hapten-bound germline Fab of antibody 28B4 were determined. Comparison with the previously determined structures of the unliganded and hapten-bound affinity-matured Fab [Hsieh-Wilson, L.C., Schultz, P.G., and Stevens, R.C. (1996) Proc. Nad. Acad. Sci. U.S.A. 93, 5363] shows that the gem-dine antibody binds the p-nitrophenyl ring of hapten 3 in an orientation significantly different from that seen in the affinity matured antibody, whereas the phosphonate moiety is bound in a similar mode by both antibodies. The affinity-matured antibody 28B4 has more electrostatic and hydrophobic interactions with hapten 3 than the germline antibody and binds the hapten in a lock-and-key fashion. In contrast, significant conformational changes occur in the loops of CDR H3 and CDR LI upon hapten binding to the germline antibody, consistent with the notion of structural plasticity in the germline antibody-combining site [Wedemayer, G. J., Patten, P. A., Wang, L. H., Schultz, P. G., and Stevens, R. C. (1997) Science 276, 1665]. The structural differences are reflected in the differential binding affinities of the germline Fab (K-d=25 muM) and 28B4 Fab (K-d=37 nM) to hapten 3. Nine replacement mutations were found to accumulate in the affinity-matured antibody 28B4 compared to its germline precursor. The effects of each mutation on the binding affinity of the antibody to hapten 3 were characterized in detail in the contexts of both the germline and the affinity-matured antibodies. One of the mutations, Asp95(H)Trp, leads to a change in the orientation of the bound hapten, and its presence is a prerequisite for other somatic mutations to enhance the binding affinity of the germline antibody for hapten 3. Thus, the germline antibody of 28B4 acquired functionally important mutations in a stepwise manner, which fits into a multicycle mutation, affinity selection, and clonal expansion model for germline antibody evolution. Two other antibodies, 20-1 and NZA6, with very different antigen specificities were found to be highly homologous to the germline antibody of 28B4, consistent with the notion that certain germline variable-region gene combinations can give rise to polyspecific hapten binding sites [Romesberg, F. E., Spiller, B.. Schultz, P. G., and Stevens, R. C. (1998) Science 279, 1929]. The ultimate specificity of the polyspecific germline antibody appears to be defined by CDR H3 variability and subsequent somatic mutation. Insights into the evolution of antibody-combining sites provided by this and other structural studies are discussed. C1 Scripps Res Inst, Dept Chem & Mol Biol, La Jolla, CA 92037 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Scripps Res Inst, Dept Mol & Expt Med, La Jolla, CA 92037 USA. Aventis Pharma, Struct Biol Chem, D-65926 Frankfurt, Germany. RP Stevens, RC (reprint author), Scripps Res Inst, Dept Chem & Mol Biol, 10550 N Torrey Pines Rd, La Jolla, CA 92037 USA. RI Stevens, Raymond/K-7272-2015 OI Stevens, Raymond/0000-0002-4522-8725 NR 35 TC 51 Z9 52 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD SEP 11 PY 2001 VL 40 IS 36 BP 10764 EP 10773 DI 10.1021/bi010536c PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 470NC UT WOS:000170877200004 PM 11535051 ER PT J AU Grayson, SM Frechet, JMJ AF Grayson, SM Frechet, JMJ TI Divergent synthesis of dendronized poly(p-hydroxystyrene) SO MACROMOLECULES LA English DT Article ID DENDRIMERS; POLYMERS; POLYMERIZATION C1 Univ Calif Berkeley, Dept Chem, Ctr New Direct Organ Synth, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Frechet, JMJ (reprint author), Univ Calif Berkeley, Dept Chem, Ctr New Direct Organ Synth, Berkeley, CA 94720 USA. EM frechet@cchem.berkeley.edu NR 19 TC 97 Z9 98 U1 1 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 11 PY 2001 VL 34 IS 19 BP 6542 EP 6544 DI 10.1021/ma010698g PG 3 WC Polymer Science SC Polymer Science GA 470CU UT WOS:000170853500006 ER PT J AU Harris, DJ Assink, RA Celina, M AF Harris, DJ Assink, RA Celina, M TI NMR analysis of oxidatively aged HTPB/IPDI polyurethane rubber: Degradation products, dynamics, and heterogeneity SO MACROMOLECULES LA English DT Article ID PROTON SPIN-DIFFUSION; POLYMERS; EXTRAPOLATION; SPECTROSCOPY; MORPHOLOGY; RELAXATION; SEPARATION; ARRHENIUS; MOBILITY AB NMR spectroscopy experiments on thermally aged cross-linked hydroxyl-terminated polybutadiene (HTPB)/isophorone diisocyanate (IPDI) based polyurethane rubber indicated only a slight temperature dependence for the degradation products distribution but revealed the presence of chemical and dynamic heterogeneities. The samples were aged in sealed ampules containing either oxygen or O-17(2) gas at temperatures ranging from ambient temperature to 125 degreesC. The O-17 and C-13 NMR spectra showed that alcohols are the dominant oxygen-containing degradation products (similar to 60%). Ester and acid functional groups were also detected, but there was no significant amount of ketones. Gel permeation chromatography (GPC) showed evidence of both chain scission and cross-linking during degradation. The dynamics in the rubber system was probed with wide-line H-1 spectra, H-1 spin diffusion measurements, and 2D wide-line-separation (WISE) experiments. Dynamic and chemical heterogeneities were detected in highly aged materials. The smallest dimension of the chemically pristine mobile regions is similar to 20 nm. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Harris, DJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 20 TC 24 Z9 29 U1 1 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD SEP 11 PY 2001 VL 34 IS 19 BP 6695 EP 6700 DI 10.1021/ma0108766 PG 6 WC Polymer Science SC Polymer Science GA 470CU UT WOS:000170853500029 ER PT J AU Brown, P Cooke, B AF Brown, P Cooke, B TI Model predictions for the 2001 Leonids and implications for Earth-orbiting satellites SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE comets : individual : 55P/Tempel; Tuttle; meteors, meteoroids ID STREAM AB A numerical model of the Leonid stream is developed, based on an earlier model which has been applied to the Perseid stream. The results for this model are applied to the 2001 Leonid return. By examining the full three-dimensional dispersion of individual 'streamlets' released from the Leonid parent comet, 55P/Tempel-Tuttle, we have derived an estimate for the temporal change in spatial density of each trail. Using this result along with an estimate for the location of the centres for individual streamlets and fits to previous Leonid storm profiles, we estimate that the activity from the shower will be broad and relatively strong (zenithal hourly rates perhaps in excess of 1000). In particular, streamlets from the 1766 and 1799 ejections contribute to activity peaking near 10 and 12 UT on 2001 November 18, respectively. Additional older material from 1633, 1666 and 1699, as well as more recent ejections from 1866 and 1833, contributes to a much broader secondary maximum near 17.5 UT on November 18. Comparison with other published models of predicted Leonid activity in 2001 shows general agreement in terms of timing, but the models differ significantly in terms of the relative magnitude of the activity (which other models suggest will be larger). Significant anisotropy in the impact hazard exists for satellites in the geostationary belt, with those over western longitudes most likely to be affected. Integrated fluences for the 2001 Leonid return suggest a hazard of order one magnitude greater than occurred for the 1999 Leonid storm. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Western Ontario, Dept Phys & Astron, London, ON N6A 3K7, Canada. Comp Sci Corp, Engn Directorate, George C Marshall Space Flight Ctr, Huntsville, AL 35812 USA. RP Brown, P (reprint author), Los Alamos Natl Lab, EES-8, Los Alamos, NM 87545 USA. NR 16 TC 13 Z9 13 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 11 PY 2001 VL 326 IS 2 BP L19 EP L22 DI 10.1046/j.1365-8711.2001.04765.x PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 475UL UT WOS:000171186400002 ER PT J AU Adler, C Denisov, A Garcia, E Murray, M Stroebele, H White, S AF Adler, C Denisov, A Garcia, E Murray, M Stroebele, H White, S TI The RHIC zero degree calorimeters SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE heavy ions; calorimeter; luminosity ID COLLISIONS AB The RHIC zero degree calorimeters provide common event characterization in the four heavy ion experiments which recently completed their first data taking run. Here we describe simulations which lead to the design of these devices, testbeam performance and initial experience at RHIC. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. IHEP, Protvino, Russia. Univ Frankfurt, IKF, D-6000 Frankfurt, Germany. Texas A&M Cyclotron, College Stn, TX 77843 USA. Univ Maryland, College Pk, MD 20742 USA. RP White, S (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 9 TC 119 Z9 119 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 SEP 11 PY 2001 VL 470 IS 3 BP 488 EP 499 DI 10.1016/S0168-9002(01)00627-1 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 474PH UT WOS:000171115600003 ER PT J AU Geist, WH Carrillo, LA Ensslin, N Ianakiev, K Mayo, DR Miller, MC AF Geist, WH Carrillo, LA Ensslin, N Ianakiev, K Mayo, DR Miller, MC TI Evaluation of a fast neutron coincidence counter for the measurements of uranium samples SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB A fast neutron coincidence counter using BC454/BGO phoswich detectors has been evaluated for the purpose of rapid verification measurements of uranium items. This counter uses custom electronics to identify and count coincidence neutrons in the presence of background radiation. Measurements of uranium standards were performed to evaluate the counter, This counter is successful in measuring uranium items but has a low efficiency that results in minimal improvement over current technology. An optimized counter can be built with better performance capabilities, but it is recommended that newer technologies be used instead. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Geist, WH (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 11 TC 2 Z9 3 U1 1 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 SEP 11 PY 2001 VL 470 IS 3 BP 590 EP 599 DI 10.1016/S0168-9002(01)00803-8 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 474PH UT WOS:000171115600013 ER PT J AU Hu, FS Ito, E Brown, TA Curry, BB Engstrom, DR AF Hu, FS Ito, E Brown, TA Curry, BB Engstrom, DR TI Pronounced climatic variations in Alaska during the last two millennia SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID TEMPERATURE-CHANGES; AIR-TEMPERATURE; RECORD; LAKE AB Paired oxygen-isotopic analyses of abiotic carbonate and benthic-ostracode shells from lake sediments provide a continuous quantitative record of growing-season temperature for the past 2000 years in the northwestern foothills of the Alaska Range. This record reveals three time intervals of comparable warmth: anno Domini (A.D.) 0-300, 850-1200, and post-1800, the latter two of which correspond to the Medieval Climatic Anomaly and climatic amelioration after the end of the Little Ice Age. The Little Ice Age culminated at A.D. 1700, when the climate was approximate to1.7 degreesC colder than at present. A marked climatic cooling also occurred around A.D. 600, coinciding with extensive glacial advances in Alaska. Comparisons of this temperature record with ostracode trace-element ratios (Mg/Ca, Sr/Ca) further suggest that colder periods were wetter and vice versa during the past 2000 years. C1 Univ Illinois, Dept Plant Biol, Urbana, IL 61801 USA. Univ Illinois, Dept Geol, Urbana, IL 61801 USA. Univ Minnesota, Limnol Res Ctr, Minneapolis, MN 55455 USA. Univ Minnesota, Dept Geol & Geophys, Minneapolis, MN 55455 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94551 USA. Illinois State Geol Survey, Champaign, IL 61820 USA. Sci Museum Minnesota, St Croix Watershed Res Stn, Marine St Croix, MN 55047 USA. RP Hu, FS (reprint author), Univ Illinois, Dept Plant Biol, Urbana, IL 61801 USA. NR 32 TC 84 Z9 86 U1 0 U2 15 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 11 PY 2001 VL 98 IS 19 BP 10552 EP 10556 DI 10.1073/pnas.181333798 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 472CZ UT WOS:000170966800012 PM 11517320 ER PT J AU Liu, Y Ogata, CM Hendrickson, WA AF Liu, Y Ogata, CM Hendrickson, WA TI Multiwavelength anomalous diffraction analysis at the M absorption edges of uranium SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE MAD; protein crystallography; resonance scattering; x-ray absorption ID SYNCHROTRON RADIATION; MAD ANALYSIS; X-RAYS; RESOLUTION; SCATTERING; DISPERSION; SPECTRA; PROTEIN AB The multiwavelength anomalous diffraction (MAD) method for phase evaluation is now widely used in macromolecular crystallography. Successful MAD structure determinations have been carried out at the K or L absorption edges of a variety of elements. In this study, we investigate the anomalous scattering properties of uranium at its M-IV (3.326 Angstrom) and M-V (3.490 Angstrom) edge. Fluorescence spectra showed remarkably strong anomalous scattering at these edges (f ' = -70e, f " = 80e at the M-IV edge and f ' = -90e, f " = 105e at the Mv edge), many times higher than from any anomalous scatterers used previously for MAD phasing. However, the large scattering angles and high absorption at the low energies of these edges present some difficulties not found in typical crystallographic studies. We conducted test experiments at the M-IV edge with crystals of porcine elastase derivatized with uranyl nitrate. A four-wavelength MAD data set complete to 3.2-Angstrom Bragg spacings was collected from a single small frozen crystal. Analysis of the data yielded satisfactory phase information (average difference of (0)(phiT) - (0)(phiA) for replicated determinations is 32 degrees) and produced an interpretable electron-density map. Our results demonstrate that it is practical to measure macromolecular diffraction data at these edges with current instrumentation and that phase information of good accuracy can be extracted from such experiments. We show that such experiments have potential for the phasing of very large macromolecular assemblages. C1 Brookhaven Natl Lab, Howard Hughes Med Inst, Upton, NY 11793 USA. Brookhaven Natl Lab, Natl Synchtron Light Source X4, Upton, NY 11793 USA. RP Hendrickson, WA (reprint author), Brookhaven Natl Lab, Howard Hughes Med Inst, Upton, NY 11793 USA. FU NIGMS NIH HHS [GM34102, R01 GM034102, R37 GM034102] NR 22 TC 16 Z9 17 U1 0 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 11 PY 2001 VL 98 IS 19 BP 10648 EP 10653 DI 10.1073/pnas.191003998 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 472CZ UT WOS:000170966800029 PM 11526210 ER PT J AU Spence, MM Rubin, SM Dimitrov, IE Ruiz, EJ Wemmer, DE Pines, A Yao, SQ Tian, F Schultz, PG AF Spence, MM Rubin, SM Dimitrov, IE Ruiz, EJ Wemmer, DE Pines, A Yao, SQ Tian, F Schultz, PG TI Functionalized xenon as a biosensor SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID LASER-POLARIZED XENON; HYPERPOLARIZED XE-129 NMR; MAGNETIC-RESONANCE; CRYPTOPHANE-A; PROTEINS; ENHANCEMENT; TECHNOLOGY; MYOGLOBIN; BINDING; MRI AB The detection of biological molecules and their interactions is a significant component of modern biomedical research. In current biosensor technologies, simultaneous detection is limited to a small number of analytes by the spectral overlap of their signals. We have developed an NMR-based xenon biosensor that capitalizes on the enhanced signal-to-noise, spectral simplicity, and chemical-shift sensitivity of laser-polarized xenon to detect specific biomolecules at the level of tens of nanomoles. We present results using xenon "functionalized" by a biotin-modified supramolecular cage to detect biotin-avidin binding. This biosensor methodology can be extended to a multiplexing assay for multiple analytes. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Phys Biosci, Berkeley, CA 94720 USA. Univ Penn, Dept Radiol, Philadelphia, PA 19104 USA. Scripps Res Inst, Skaggs Inst Chem Biol, La Jolla, CA 92037 USA. RP Pines, A (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Yao, Shao/B-8825-2008 FU NCRR NIH HHS [P41 RR002305, RR02305] NR 29 TC 188 Z9 192 U1 3 U2 36 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 11 PY 2001 VL 98 IS 19 BP 10654 EP 10657 DI 10.1073/pnas.191368398 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 472CZ UT WOS:000170966800030 PM 11535830 ER PT J AU Wang, JH Meijers, R Xiong, Y Liu, JH Sakihama, T Zhang, RG Joachimiak, A Reinherz, EL AF Wang, JH Meijers, R Xiong, Y Liu, JH Sakihama, T Zhang, RG Joachimiak, A Reinherz, EL TI Crystal structure of the human CD4 N-terminal two-domain fragment complexed to a class II MHC molecule SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID T-CELL ACTIVATION; IMMUNODEFICIENCY-VIRUS GP120; ENVELOPE GLYCOPROTEIN; BETA-CHAINS; BINDING; RECEPTOR; ANTIGENS; ALPHA; CD8-ALPHA-ALPHA; OLIGOMERIZATION AB The structural basis of the interaction between the CD4 coreceptor and a class II major histocompatibility complex (MHC) is described. The crystal structure of a complex containing the human CD4 N-terminal two-domain fragment and the murine I-A(k) class II MHC molecule with associated peptide (pMHCII) shows that only the "top corner" of the CD4 molecule directly contacts pMHCII. The CD4 Phe-43 side chain extends into a hydrophobic concavity formed by MHC residues from both alpha2 and beta2 domains. A ternary model of the CD4-pMHCII-T-cell receptor (TCR) reveals that the complex appears V-shaped with the membrane-proximal pMHCII at the apex. This configuration excludes a direct TCR-CD4 interaction and suggests how TCR and CD4 signaling is coordinated around the antigenic pMHCII complex. Human CD4 binds to HIV gp120 in a manner strikingly similar to the way in which CD4 interacts with pMHCII. Additional contacts between gp120 and CD4 give the CD4-gp120 complex a greater affinity. Thus, ligation of the viral envelope glycoprotein to CD4 occludes the pMHCII-binding site on CD4, contributing to immunodeficiency. C1 Dana Farber Canc Inst, Immunobiol Lab, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Mol Pharmacol, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Biol Chem & Mol Pharmacol, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Pediat, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Med, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Med, Boston, MA 02115 USA. Dana Farber Canc Inst, Dept Canc Immunol, Boston, MA 02115 USA. Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. RP Wang, JH (reprint author), Dana Farber Canc Inst, Immunobiol Lab, Boston, MA 02115 USA. RI Meijers, Rob/D-5521-2011; OI Meijers, Rob/0000-0003-2872-6279 NR 47 TC 156 Z9 163 U1 0 U2 3 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 11 PY 2001 VL 98 IS 19 BP 10799 EP 10804 DI 10.1073/pnas.191124098 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 472CZ UT WOS:000170966800055 PM 11535811 ER PT J AU Sorlie, T Perou, CM Tibshirani, R Aas, T Geisler, S Johnsen, H Hastie, T Eisen, MB van de Rijn, M Jeffrey, SS Thorsen, T Quist, H Matese, JC Brown, PO Botstein, D Lonning, PE Borresen-Dale, AL AF Sorlie, T Perou, CM Tibshirani, R Aas, T Geisler, S Johnsen, H Hastie, T Eisen, MB van de Rijn, M Jeffrey, SS Thorsen, T Quist, H Matese, JC Brown, PO Botstein, D Lonning, PE Borresen-Dale, AL TI Gene expression patterns of breast carcinomas distinguish tumor subclasses with clinical implications SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID GROWTH-FACTOR RECEPTOR; PROGNOSTIC-SIGNIFICANCE; PROGESTERONE RECEPTORS; SYSTEMIC THERAPY; CANCER PATIENTS; P53; MUTATIONS; SURVIVAL; ESTROGEN AB The purpose of this study was to classify breast carcinomas based on variations in gene expression patterns derived from cDNA microarrays and to correlate tumor characteristics to clinical outcome. A total of 85 cDNA microarray experiments representing 78 cancers, three fibroadenomas, and four normal breast tissues were analyzed by hierarchical clustering. As reported previously, the cancers could be classified into a basal epithelial-like group, an ERBB2-overexpressing group and a normal breast-like group based on variations in gene expression. A novel finding was that the previously characterized luminal epithelial/estrogen receptor-positive group could be divided into at least two subgroups, each with a distinctive expression profile. These subtypes proved to be reasonably robust by clustering using two different gene sets: first, a set of 456 cDNA clones previously selected to reflect intrinsic properties of the tumors and, second, a gene set that highly correlated with patient outcome. Survival analyses on a subcohort of patients with locally advanced breast cancer uniformly treated in a prospective study showed significantly different outcomes for the patients belonging to the various groups, including a poor prognosis for the basal-like subtype and a significant difference in outcome for the two estrogen receptor-positive groups. C1 Norwegian Radium Hosp, Dept Genet, N-0310 Oslo, Norway. Norwegian Radium Hosp, Dept Surg, N-0310 Oslo, Norway. Univ N Carolina, Dept Genet, Chapel Hill, NC 27599 USA. Univ N Carolina, Lineberger Comprehens Canc Ctr, Chapel Hill, NC 27599 USA. Stanford Univ, Sch Med, Howard Hughes Med Inst, Stanford, CA 94305 USA. Stanford Univ, Sch Med, Dept Biochem, Stanford, CA 94305 USA. Stanford Univ, Sch Med, Dept Surg, Stanford, CA 94305 USA. Stanford Univ, Sch Med, Dept Pathol, Stanford, CA 94305 USA. Stanford Univ, Sch Med, Dept Genet, Stanford, CA 94305 USA. Stanford Univ, Sch Med, Dept Hlth Res & Policy & Stat, Stanford, CA 94305 USA. Haukeland Univ Hosp, Dept Med, Sect Oncol, N-5021 Bergen, Norway. Haukeland Univ Hosp, Dept Surg, N-5021 Bergen, Norway. Haukeland Univ Hosp, Dept Biochem Endocrinol, N-5021 Bergen, Norway. Lawrence Orlando Berkeley Natl Labs, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mol & Cellular Biol, Berkeley, CA 94720 USA. RP Borresen-Dale, AL (reprint author), Norwegian Radium Hosp, Dept Genet, N-0310 Oslo, Norway. RI Sorlie, Therese/B-1413-2015; OI Sorlie, Therese/0000-0002-5995-2319; Eisen, Michael/0000-0002-7528-738X; Perou, Charles/0000-0001-9827-2247 FU NCI NIH HHS [U01 CA085129] NR 20 TC 5400 Z9 5569 U1 43 U2 312 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 11 PY 2001 VL 98 IS 19 BP 10869 EP 10874 DI 10.1073/pnas.191367098 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 472CZ UT WOS:000170966800067 PM 11553815 ER PT J AU de Leon, MJ Convit, A Wolf, OT Tarshish, CY DeSanti, S Rusinek, H Tsui, W Kandil, E Scherer, AJ Roche, A Imossi, A Thorn, E Bobinski, M Caraos, C Lesbre, P Schlyer, D Poirier, J Reisberg, B Fowler, J AF de Leon, MJ Convit, A Wolf, OT Tarshish, CY DeSanti, S Rusinek, H Tsui, W Kandil, E Scherer, AJ Roche, A Imossi, A Thorn, E Bobinski, M Caraos, C Lesbre, P Schlyer, D Poirier, J Reisberg, B Fowler, J TI Prediction of cognitive decline in normal elderly subjects with 2-[F-18]fluoro-2-deoxy-D-glucose/positron-emission tomography (FDG/PET) SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID MILD ALZHEIMERS-DISEASE; POSITRON EMISSION TOMOGRAPHY; APOLIPOPROTEIN-E GENOTYPE; HIPPOCAMPAL VOLUME; NEUROFIBRILLARY CHANGES; GLUCOSE-METABOLISM; MEMORY IMPAIRMENT; ENTORHINAL CORTEX; DEMENTIA; RISK AB Neuropathology studies show that patients with mild cognitive impairment (MCl) and Alzheimer's disease typically have lesions of the entorhinal cortex (EC), hippocampus (Hip), and temporal neocortex., Related observations with in vivo imaging have enabled the prediction of dementia from MCl. Although individuals with normal cognition may have focal EC lesions, this anatomy has not been studied,as a predictor of cognitive decline and brain change. The objective of this MRI-guided 2-[F-18]fluoro-2-deoxy-D-glucose/ positron-emission tomography (FDG/PET) study was to examine the hypothesis that among normal elderly subjects, EC METglu reductions predict decline and the involvement of the Hip and neocortex. In a 3-year longitudinal study of 48 healthy normal elderly, 12 individuals (mean age 72) demonstrated cognitive decline (11 to MCl and 1 to Alzheimer's disease). Nondeclining controls were matched on apolipoprotein E genotype, age, education, and gender. At baseline, metabolic reductions in the EC accurately predicted the conversion from normal to MCl. Among those who declined, the baseline EC predicted longitudinal memory and temporal neocortex metabolic reductions. At follow-up, those who declined showed memory impairment and hypometabolism in temporal lobe neocortex and Hip. Among those subjects who declined, apolipoprotein E E4 carriers showed marked longitudinal temporal neocortex reductions. In summary, these data suggest that an EC stage of brain involvement can be detected in normal elderly that predicts future cognitive and brain metabolism reductions. Progressive E4-related hypometabolism may underlie the known increased susceptibility for dementia. Further study is required to estimate individual risks and to determine the physiologic basis for METglu changes detected while cognition is normal. C1 NYU, Sch Med, Ctr Brain Hlth HN400, New York, NY 10016 USA. Nathan S Kline Inst Psychiat Res, Orangeburg, NY 10962 USA. Univ Dusseldorf, D-40225 Dusseldorf, Germany. Brookhaven Natl Lab, Upton, NY 11973 USA. McGill Univ, Verdun, PQ H4H 1R3, Canada. RP de Leon, MJ (reprint author), NYU, Sch Med, Ctr Brain Hlth HN400, 560 1st Ave, New York, NY 10016 USA. OI de Leon, Mony/0000-0003-2245-4380 FU NIA NIH HHS [R01 AG012101, AG03051, AG08051, AG12101, AG13616, P30 AG008051, R01 AG003051, R01 AG013616] NR 47 TC 378 Z9 386 U1 2 U2 14 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD SEP 11 PY 2001 VL 98 IS 19 BP 10966 EP 10971 DI 10.1073/pnas.191044198 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 472CZ UT WOS:000170966800083 PM 11526211 ER PT J AU Minor, AM Morris, JW Stach, EA AF Minor, AM Morris, JW Stach, EA TI Quantitative in situ nanoindentation in an electron microscope SO APPLIED PHYSICS LETTERS LA English DT Article ID DEFORMATION; INDENTATION; HARDNESS AB We report the development of a method for quantitative, in situ nanoindentation in an electron microscope and its application to study the onset of deformation during the nanoindentation of aluminum films. The force-displacement curve developed shows the characteristic "staircase" instability at the onset of plastic deformation. This instability corresponds to the first appearance of dislocations in a previously defect-free grain. Plastic deformation proceeds through the formation and propagation of prismatic loops punched into the material, and half loops that emanate from the sample surface. These results represent the first real time observations of the discrete microstructural events that occur during nanoindentation. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Natl Ctr Electron Microscopy, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Minor, AM (reprint author), Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. RI Stach, Eric/D-8545-2011 OI Stach, Eric/0000-0002-3366-2153 NR 9 TC 94 Z9 97 U1 2 U2 36 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 10 PY 2001 VL 79 IS 11 BP 1625 EP 1627 DI 10.1063/1.1400768 PG 3 WC Physics, Applied SC Physics GA 469EB UT WOS:000170800700014 ER PT J AU Wang, K Atkins, R Benbow, W Berley, D Chen, ML Coyne, DG Dingus, BL Dorfan, DE Ellsworth, RW Falcone, A Fleysher, L Fleysher, R Gisler, G Goodman, JA Haines, TJ Hoffman, CM Hugenberger, S Kelley, LA Leonor, I McConnell, M McCullough, JF McEnery, JE Miller, RS Mincer, AI Morales, MF Nemethy, P Ryan, JM Samuelson, FW Shen, B Shoup, A Sinnis, G Smith, AJ Sullivan, GW Tumer, OT Wascko, O Westerhoff, S Williams, DA Yang, T Yodh, GB AF Wang, K Atkins, R Benbow, W Berley, D Chen, ML Coyne, DG Dingus, BL Dorfan, DE Ellsworth, RW Falcone, A Fleysher, L Fleysher, R Gisler, G Goodman, JA Haines, TJ Hoffman, CM Hugenberger, S Kelley, LA Leonor, I McConnell, M McCullough, JF McEnery, JE Miller, RS Mincer, AI Morales, MF Nemethy, P Ryan, JM Samuelson, FW Shen, B Shoup, A Sinnis, G Smith, AJ Sullivan, GW Tumer, OT Wascko, O Westerhoff, S Williams, DA Yang, T Yodh, GB CA Milagro Collaboration TI A survey of the northern sky for TeV point sources SO ASTROPHYSICAL JOURNAL LA English DT Article DE gamma rays : observations; surveys ID GAMMA-RAY ASTRONOMY; MARKARIAN-501; RADIATION; MILAGRITO; SPECTRUM; SEARCH AB A search for steady TeV point sources anywhere in the northern sky has been made with data from the Milagrito air-shower particle detector. Over 3x10(9) events, collected from 1997 February to 1998 May, have been used in this study. No statistically significant excess above the background from the isotropic flux of cosmic rays was found for any direction of the sky with declination between -5 degrees and 71.degrees7. Upper limits are derived for the photon flux above 1 TeV from any steady point source in the northern sky. C1 Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. George Mason Univ, Dept Phys, Fairfax, VA 22030 USA. Univ New Hampshire, Dept Phys, Durham, NH 03824 USA. NYU, Dept Phys, New York, NY 10003 USA. Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87544 USA. Los Alamos Natl Lab, Nonproliferat & Int Secur Div, Los Alamos, NM 87544 USA. Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. RP Wang, K (reprint author), Amillaire Technol Inc, Bethesda, MD 20817 USA. OI Dingus, Brenda/0000-0001-8451-7450 NR 23 TC 6 Z9 6 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2001 VL 558 IS 2 BP 477 EP 481 DI 10.1086/322312 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 472TW UT WOS:000171001900001 ER PT J AU Hamuy, M Pinto, PA Maza, J Suntzeff, NB Phillips, MM Eastman, RG Smith, RC Corbally, CJ Burstein, D Li, Y Ivanov, V Moro-Martin, A Strolger, LG de Souza, RE dos Anjos, S Green, EM Pickering, TE Gonzalez, L Antezana, R Wischnjewsky, M Galaz, G Roth, M Persson, SE Schommer, RA AF Hamuy, M Pinto, PA Maza, J Suntzeff, NB Phillips, MM Eastman, RG Smith, RC Corbally, CJ Burstein, D Li, Y Ivanov, V Moro-Martin, A Strolger, LG de Souza, RE dos Anjos, S Green, EM Pickering, TE Gonzalez, L Antezana, R Wischnjewsky, M Galaz, G Roth, M Persson, SE Schommer, RA TI The distance to SN 1999em from the expanding photosphere method SO ASTROPHYSICAL JOURNAL LA English DT Article DE distance scale; galaxies : distances and redshifts; supernovae : general; supernovae : individual (SN 1999em) ID INFRARED STANDARD STARS; II SUPERNOVAE; LINE IDENTIFICATIONS; VRI PHOTOMETRY; IA SUPERNOVAE; SPECTROSCOPY; SN-1987A; CALIBRATION; EMISSION; SPECTRUM AB We present optical and infrared spectroscopy of the first 2 months of evolution of the Type II supernova SN 1999em. We combine these data with high-quality optical/infrared photometry beginning only 3 days after shock breakout, in order to study the performance of the " expanding photosphere method II (EPM) in the determination of distances. With this purpose, we develop a technique to measure accurate photospheric velocities by cross-correlating observed and model spectra. The application of this technique to SN 1999em shows that we can reach an average uncertainty of 11% in velocity from an individual spectrum. Our analysis shows that EPM is quite robust to the effects of dust. In particular, the distances derived from the VI filters change by only 7% when the adopted visual extinction in the host galaxy is varied by 0.45 mag. The superb time sampling of the BV IZJHK light curves of SN 1999em permits us to study the internal consistency of EPM and test the dilution factors computed from atmosphere models for Type II plateau supernovae. We find that, in the first week since explosion, the EPM distances are up to 50% lower than the average, possibly because of the presence of circumstellar material. Over the following 65 days, on the other hand, our tests lend strong credence to the atmosphere models, and confirm previous claims that EPM can produce consistent distances without having to craft specific models to each supernova. This is particularly true for the V I filters, which yield distances with an internal consistency of 4%. From the whole set of BV IZJHK photometry, we obtain an average distance of 7.5 +/- 0.5 Mpc, where the quoted uncertainty (7%) is a conservative estimate of the internal precision of the method obtained from the analysis of the first 70 days of the supernova evolution. C1 Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. Univ Chile, Dept Astron, Santiago, Chile. Cerro Tololo Interamer Observ, Natl Opt Astron Observ, La Serena, Chile. Las Campanas Observ, Carnegie Inst Washington, La Serena, Chile. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Arizona, Vatican Observ, Tucson, AZ 85721 USA. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Univ Michigan, Dept Astron, Ann Arbor, MI 48109 USA. Observ Carnegie Inst Washington, Pasadena, CA 91101 USA. Univ Sao Paulo, Dept Astron, BR-01065 Sao Paulo, Brazil. RP Hamuy, M (reprint author), Univ Arizona, Steward Observ, Tucson, AZ 85721 USA. RI Maza, Jose/I-5722-2016; Hamuy, Mario/G-7541-2016 OI Maza, Jose/0000-0003-2068-1328; NR 56 TC 143 Z9 144 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 10 PY 2001 VL 558 IS 2 BP 615 EP 642 DI 10.1086/322450 PN 1 PG 28 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 472TW UT WOS:000171001900015 ER PT J AU Paul, M Valenta, A Ahmad, I Berkovits, D Bordeanu, C Ghelberg, S Hashimoto, Y Hershkowitz, A Jiang, S Nakanishi, T Sakamoto, K AF Paul, M Valenta, A Ahmad, I Berkovits, D Bordeanu, C Ghelberg, S Hashimoto, Y Hershkowitz, A Jiang, S Nakanishi, T Sakamoto, K TI Experimental limit to interstellar Pu-244 abundance SO ASTROPHYSICAL JOURNAL LA English DT Article DE instrumentation : spectrographs; ISM : abundances; methods : laboratory; nuclear reactions, nucleosynthesis, abundances ID DUST MEASUREMENTS; SUPERNOVA; PLUTONIUM-244; ELEMENTS; GRAINS; SOLAR; FE-60; EARTH AB Short-lived nuclides, now extinct in the solar system, are expected to be present in the interstellar medium (ISM). Grains of ISM origin were recently discovered in the inner solar system and at Earth orbit and may accrete onto Earth after ablation in the atmosphere. A favorable matrix for detection of such extraterrestrial material is presented by deep-sea sediments with very low sedimentation rates (0.8-3 mm kyr(-1)). We report here on the measurement of Pu isotopic abundances in a 1 kg deep-sea dry sediment collected in 1992 in the North Pacific. Our estimate of (3 +/- 3) x 10(5) Pu-244 atoms in the Pu-separated fraction of the sample shows no excess over the expected stratospheric nuclear fallout content and, under reasonable assumptions, sets a limit of 0.2 Pu-244 atoms cm(-2) yr(-1) for extraterrestrial deposition. Using the available data on the ISM steady-state flux on Earth, we derive a limit of 2 x 10(-11) g Pu-244 (g ISM)(-1) for the abundance of Pu-244 in the ISM. C1 Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. Univ Vienna, VERA Lab, Inst Isotopenforsch & Kernphys, A-1090 Vienna, Austria. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Soreq NRC, IL-81800 Yavne, Israel. Weizmann Inst Sci, Particle Phys Dept, IL-76100 Rehovot, Israel. Kanazawa Univ, Fac Sci, Dept Chem, Kanazawa, Ishikawa 9201192, Japan. RP Paul, M (reprint author), Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. RI Bordeanu, Cristina/J-3438-2012 OI Bordeanu, Cristina/0000-0003-4641-0630 NR 27 TC 33 Z9 33 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 SEP 10 PY 2001 VL 558 IS 2 BP L133 EP L135 DI 10.1086/323617 PN 2 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 472UE UT WOS:000171002700014 ER PT J AU Hu, ZB George, GN Gorun, SM AF Hu, ZB George, GN Gorun, SM TI Fluorine encapsulation and stabilization of biologically relevant low-valence copper-oxo cores SO INORGANIC CHEMISTRY LA English DT Article ID DIOXYGEN COMPLEXES; REACTIVITY; HEMOCYANIN; OXYGENASES; TYROSINASE; OXIDASES; BINDING; SITES; MODEL AB Slow crystallization of the dinuclear [(CuTp(3)(3)(CF)(,CH))(2)O-2] yields a solid-state solution of the peroxo and bis(hydroxo) complex, but not sterically compressed Cu(III) complexes. Since the CF3 substituents, while Space-filing view of [(CuTp(3)(3)(CF)(,CH))(2)O-2] showing the green region of fluorine steric hindrance of the metal-peroxo core. The two-fold rotationally disordered CF3 groups are shown in full. C1 Brown Univ, Dept Chem, Providence, RI 02912 USA. Stanford Synchrotron Radiat Lab, SLAC, Menlo Pk, CA 94025 USA. RP Gorun, SM (reprint author), Brown Univ, Dept Chem, Providence, RI 02912 USA. RI George, Graham/E-3290-2013 NR 27 TC 33 Z9 33 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 10 PY 2001 VL 40 IS 19 BP 4812 EP + DI 10.1021/ic015529r PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 470RA UT WOS:000170883900001 PM 11531422 ER PT J AU Pirani, AM Mercier, HPA Dixon, DA Borrmann, H Schrobilgen, GJ AF Pirani, AM Mercier, HPA Dixon, DA Borrmann, H Schrobilgen, GJ TI Syntheses, vibrational spectra, and theoretical studies of the adamantanoid Sn(4)Ch(10)(4-) (Ch = Se, Te) anions: X-ray crystal structures of [18-crown-6-K](4)[Sn4Se10]center dot 5en and [18-Crown-6-K](4)[Sn4Te10]center dot 3en center dot 2THF SO INORGANIC CHEMISTRY LA English DT Article ID MULTINUCLEAR MAGNETIC-RESONANCE; RAMAN-SPECTRA; BOND ORDERS; GERMANIUM SULFIDE; SCF THEORY; VALENCES; SE-77; CHEMISTRY; MOLECULES; ENERGIES AB The salts [18-crown-6-K](4)[Sn4Se10]. 5en and [18-crown-6-K](4)[Sn4Te10]. 3en . 2THF were isolated upon addition of THF to the ethylenediamine (en) extracts of the alloys KSn0.90Se1.93 and K4Sn4Te10 that had been extracted in the presence of 18-crown-6 (1,4,7,10,13,16-hexaoxacyclooctadecane). The Sn4Te104- anion has been structurally characterized for the first time by a single-crystal X-ray diffraction study of [ 18-crown-6-K](4)[Sn4Te10]. 3en . 2THF: P2(1)/n, a = 22.420(5) Angstrom, b = 19.570(4) Angstrom, c = 24.680(5) Angstrom, beta = 96.90(3)degrees, Z = 4, and R-1 = 0.0468 at -183 degreesC. In addition to Si4Te104- and Ge4Te104-, the Sn4Te104- anion represents the only other known group 14 adamantanoid telluride. The X-ray crystal structure determination of the related [18-crown-6-K](4)[Sn4Se10]. 5en salt has also been determined: P2(1)/n, a = 22.003(2) Angstrom, b = 18.966(2) Angstrom, c = 24.393(2) Angstrom, beta = 97.548(8)degrees, Z = 4, and R-1 = 0.0843 at -123 degreesC. The anion geometries are of the adamantanoid type where the Sn-IV atoms occupy the bridgehead positions and the chalcogen atoms occupy the bridging and terminal sites. The energy minimized geometries of Sn(4)Ch(10)(4-) have also been determined using density functional theory (DFT). Mayer bond order analyses, Mayer valencies, and empirical bond valencies indicate that the terminal Sn-Ch bonds have significant multiple bond character, with the terminal Sn-Se bond having more multiple bond character than the terminal Sn-Te bond. The vibrational frequencies of the Sn4Se104- and Sn4Te104- anions have been calculated using DFT methods, allowing the Raman spectrum of Sn4Se104- to be fully assigned. C1 McMaster Univ, Dept Chem, Hamilton, ON L8S 4M1, Canada. Pacific NW Natl Lab, William R Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Max Planck Inst Chem Phys Fester Stoffe, D-01187 Dresden, Germany. RP McMaster Univ, Dept Chem, 1280 Main St W, Hamilton, ON L8S 4M1, Canada. NR 57 TC 18 Z9 18 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 EI 1520-510X J9 INORG CHEM JI Inorg. Chem. PD SEP 10 PY 2001 VL 40 IS 19 BP 4823 EP 4829 DI 10.1021/ic010242f PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 470RA UT WOS:000170883900006 PM 11531427 ER PT J AU Piccoli, PMB Abney, KD Schoonover, JD Dorhout, PK AF Piccoli, PMB Abney, KD Schoonover, JD Dorhout, PK TI Synthesis, structure, and properties of Cs4Th4P4Se26: A quaternary thorium selenophosphate containing the (P2Se9)(6-) anion SO INORGANIC CHEMISTRY LA English DT Article ID CRYSTAL-STRUCTURE; CHALCOGENIDES; CHEMISTRY; URANIUM; FLUXES; RB AB Orange crystals of Cs4Th4P4Se26 were grown from the reaction of Th-232 and P in a Cs2Se3/Se Molten salt flux at 750 degreesC. Cs4Th4P4Se26 crystallizes in the orthorhombic space group Pbca with the unit cell parameters: a 12.0130(6), b = 14.5747(7), c = 27.134(1) Angstrom; Z = 8. The compound exhibits a three-dimensional structure, consisting of dimeric [Th2Se13] polyhedral units. The two crystallographically independent, nine-coordinate, bicapped trigonal prismatic thorium atoms share a triangular face to form the dimer, and each dimer edge-shares two selenium atoms with two other dimers to form kinked chains along the [010] direction. While this structure shares features of the previously reported Rb4U4P4Se26, including phosphorus in the 5+ oxidation state, careful inspection of the structure reveals that the selenophosphate anion that knits the structure together in three directions in both compounds is a unique (P2Se9)(6-) anion. The formula may be described best as [CS2Th2(P2Se9)(Se-2)(2)](2). The (P2Sc9)(6-) anion features a nearly linear Se-Se-Se backbone with an angle of 171 degrees and Se-Se distances that are approximately 0.2-0.3 Angstrom longer than the typical single Se-Se bond. Magnetic studies confirm that this phase contains Th(IV). Raman data for this compound is reported, and structural comparisons will be drawn to its uranium analogue, Rb4U4P4Se26. C1 Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA. Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Mat Sci Technol Div, Los Alamos, NM 87545 USA. RP Dorhout, PK (reprint author), Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA. NR 23 TC 15 Z9 15 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD SEP 10 PY 2001 VL 40 IS 19 BP 4871 EP 4875 DI 10.1021/ic0011031 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 470RA UT WOS:000170883900012 ER PT J AU Belytschko, T Mish, K AF Belytschko, T Mish, K TI Computability in non-linear solid mechanics SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article; Proceedings Paper CT 5th US National Congress on Computational Mechanics CY AUG 04-06, 1999 CL UNIV COLORADO, BOULDER, COLORADO HO UNIV COLORADO DE non-linear; finite elements; stability; continuity ID SENSITIVITY ANALYSIS; CRACK-GROWTH AB The computability of non-linear problems in solid and structural mechanics problems is examined. Several factors which contribute to the level of difficulty of a simulation are discussed: the smoothness and stability of the response, the required resolution, the uncertainties in the load, boundary conditions and initial conditions and inadequacies and uncertainties in the constitutive equation. An abstract measure of the level of difficulty is proposed, and some examples of typical engineering simulations are classified by this measure. We have put particular emphasis on engineering calculations, where many of the factors that diminish computability play a prominent role. Copyright (C) 2001 John Wiley & Sons, Ltd. C1 Northwestern Univ, Dept Mech Engn, Evanston, IL 60208 USA. Lawrence Livermore Natl Lab, Ctr Computat Engn, Livermore, CA 94550 USA. RP Belytschko, T (reprint author), Northwestern Univ, Dept Mech Engn, Evanston, IL 60208 USA. RI Belytschko, Ted/B-6710-2009 NR 22 TC 30 Z9 30 U1 2 U2 5 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD SEP 10 PY 2001 VL 52 IS 1-2 BP 3 EP 21 DI 10.1002/nme.270 PG 21 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA 463KV UT WOS:000170476100002 ER PT J AU Gerald, RE Sanchez, J Johnson, CS Klingler, RJ Rathke, JW AF Gerald, RE Sanchez, J Johnson, CS Klingler, RJ Rathke, JW TI In situ nuclear magnetic resonance investigations of lithium ions in carbon electrode materials using a novel detector SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID LI-7 NMR; DISORDERED CARBONS; HARD CARBON; MESOCARBON MICROBEADS; GRAPHITE; INSERTION; INTERCALATION; BATTERIES; SPECTROSCOPY; SURFACE AB The reversible electrochemical process (insertion/extraction) of lithium ions in graphitic carbon was monitored it? situ for the first time by Li-7 nuclear magnetic resonance (NMR) spectroscopy using a novel NMR apparatus. The compression coin cell battery imager is a simple device that combines the functions of an electrochemical cell and an NMR detector. A series of 7Li NMR spectra obtained for a blend of spherical and flaky disordered graphitic carbon particles revealed two distinct chemical shift signatures for the lithium ions that were inserted and extracted in the first electrochemical cycle. The lithium signal at similar to 50 ppm is consistent with the interplane sites for lithium ions on the sixfold axis between two stacked aromatic carbon rings aligned in registry. The second predominant lithium signal at similar to 12 ppm occurs in the chemical shift region reported for high-stage lithiated graphite and a dispersion of lithium-ion sites found in disordered carbon matrices. In addition, we observed chemical shift signatures similar to those assigned to Li-7 nuclei in lithium oxide, lithium carbonate, lithium alkyls, and lithium alkoxides that occur near 0 ppm and represent lithium nuclei that are irreversibly bound in the electrode/electrolyte interphase. An increase in intensity in the spectral region that is normally associated with irreversibly bound lithium was observed during the first discharge cycle, as anticipated. However, the same peaks in the spectrum unexpectedly diminished during the subsequent charge cycle, suggesting that the interphase between the carbon electrode and the electrolyte is built up over several cycles. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Gerald, RE (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 66 TC 26 Z9 26 U1 3 U2 32 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD SEP 10 PY 2001 VL 13 IS 36 BP 8269 EP 8285 DI 10.1088/0953-8984/13/36/304 PG 17 WC Physics, Condensed Matter SC Physics GA 482KC UT WOS:000171574500006 ER PT J AU Mielke, C Singleton, J Nam, MS Harrison, N Agosta, CC Fravel, B Montgomery, LK AF Mielke, C Singleton, J Nam, MS Harrison, N Agosta, CC Fravel, B Montgomery, LK TI Superconducting properties and Fermi-surface topology of the quasi-two-dimensional organic superconductor lambda-(BETS)(2)GaCl4 (BETS bis(ethylene-dithio)tetraselenafulvalene) SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID SMALL CLOSED ORBITS; MIXED-STATE PROPERTIES; UPPER CRITICAL-FIELD; BEDT-TTF; QUASI-2-DIMENSIONAL CONDUCTORS; II SUPERCONDUCTORS; MAGNETIC-FIELDS; INTERLAYER MAGNETORESISTANCE; LAYERED METALS; KAPPA-(BEDT-TTF)(2)CU(NCS)(2) AB The Fermi-surface topology of the organic superconductor lambda-(BETS)(2)GaCl4 has been determined using the Shubnikov-de Haas and magnetic breakdown effects and angle-dependent magnetoresistance oscillations. The former experiments were carried out in pulsed fields of up to 60 T, whereas the latter employed quasistatic fields of up to 30 T. All of these data show that the Fermi-surface topology of lambda-(BETS)(2)GaCl4 is very similar to that of he most heavily studied organic superconductor, kappa-(BEDT-TTF)(2)Cu(NCS)(2), (BEDT-TTF drop bis(ethylene-dithio)tetrathiafulvalene), except in one important respect: the interplane transfer integral of lambda-(BETS)(2)GaCl4 is a factor similar to5 larger than that of kappa-(BEDT-TTF)(2)Cu(NCS)(2). The increased three-dime,nsionality of k-(BETS)(2)GaCl4 is manifested in radio-frequency penetration-depth measurements, which show a clear dimensional crossover in the behaviour of H-c2(T). The radio-frequency measurements have also been used to extract the Labusch parameter determining the fluxoid interactions as a function of temperature, and to map the flux-lattice melting curve. C1 Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Clark Univ, Dept Phys, Worcester, MA 01610 USA. Indiana Univ, Dept Chem, Bloomington, IN 47405 USA. RP Mielke, C (reprint author), Los Alamos Natl Lab, Natl High Magnet Field Lab, MS-E536, Los Alamos, NM 87545 USA. NR 83 TC 48 Z9 48 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD SEP 10 PY 2001 VL 13 IS 36 BP 8325 EP 8345 DI 10.1088/0953-8984/13/36/308 PG 21 WC Physics, Condensed Matter SC Physics GA 482KC UT WOS:000171574500010 ER PT J AU Ifti, M Li, Q Soukoulis, CM Velgakis, MJ AF Ifti, M Li, Q Soukoulis, CM Velgakis, MJ TI A study of 2D Ising ferromagnets with dipole interactions SO MODERN PHYSICS LETTERS B LA English DT Article ID ULTRATHIN MAGNETIC-FILMS; DOMAIN-STRUCTURES; CO/AU(111) FILMS; FE/CU(100); INSTABILITIES; TEMPERATURE; ANISOTROPY; DEPENDENCE; MONOLAYER AB A two-dimensional Ising model with competing short range ferromagnetic. and long range dipolar interactions is used to study the transition properties and phase diagram in ultrathin magnetic films. Monte Carlo simulations in systems with exchange and dipolar interactions reveal a ground state of striped phases with varying width. By raising the temperature, the domain walls are smeared out by fluctuations, leading to a random domain mesoscopic. phase with no long-range order, and finally the domains are melted to the high-temperature disordered phase. Local magnetic field distributions and specific heat calculations reproduced transition points consistent with the previous phase diagram of the model. The resemblance to the phase diagram in ultrathin magnetic films, such as in Fe/Cu(100), is discussed. C1 Univ Patras, Dept Engn Sci, GR-26110 Patras, Greece. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Univ Crete, FORTH, GR-71110 Iraklion, Greece. Univ Crete, Dept Phys, GR-71110 Iraklion, Greece. RP Velgakis, MJ (reprint author), Univ Patras, Dept Engn Sci, GR-26110 Patras, Greece. RI Soukoulis, Costas/A-5295-2008 NR 21 TC 3 Z9 3 U1 0 U2 4 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-9849 J9 MOD PHYS LETT B JI Mod. Phys. Lett. B PD SEP 10 PY 2001 VL 15 IS 21 BP 895 EP 903 DI 10.1142/S0217984901002695 PG 9 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA 492GX UT WOS:000172161000002 ER PT J AU Patrignani, C Ambrogiani, M Bagnasco, S Baldini, W Bettoni, D Borreani, G Buzzo, A Calabrese, R Cester, R Dalpiaz, P Garzoglio, G Gollwitzer, KE Graham, M Kasper, J Lasio, G Lo Vetere, M Luppi, E Macri, M Mandelkern, M Marchetto, F Marinelli, M Marsh, W Menichetti, E Metreveli, Z Mussa, R Negrini, M Obertino, M Pallavicini, M Pastrone, N Pedlar, T Pordes, S Robutti, E Rosen, J Rumerio, P Rusack, R Santroni, A Schultz, J Seth, KK Stancari, M Stancari, G Seo, S Tomaradze, A Vidnovic, T Werkema, S AF Patrignani, C Ambrogiani, M Bagnasco, S Baldini, W Bettoni, D Borreani, G Buzzo, A Calabrese, R Cester, R Dalpiaz, P Garzoglio, G Gollwitzer, KE Graham, M Kasper, J Lasio, G Lo Vetere, M Luppi, E Macri, M Mandelkern, M Marchetto, F Marinelli, M Marsh, W Menichetti, E Metreveli, Z Mussa, R Negrini, M Obertino, M Pallavicini, M Pastrone, N Pedlar, T Pordes, S Robutti, E Rosen, J Rumerio, P Rusack, R Santroni, A Schultz, J Seth, KK Stancari, M Stancari, G Seo, S Tomaradze, A Vidnovic, T Werkema, S CA E835 Collaboration TI E835 at FNAL: Charmonium spectroscopy in (p)over-barp annihilations SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT 6th Biennial Conference on Low-Energy Antiproton Physics (LEAP 2000) CY AUG 20-26, 2000 CL VENICE INT UNIV, VENICE, ITALY HO VENICE INT UNIV ID STATE; DECAYS AB E835 has studied the properties of the charmonium states formed in p (p) over bar annihilations. Preliminary results on the chi (c0) and eta (c) mass and width are presented. Preliminary results on the measurement of the chi (c1) and chi (c2) angular distributions are also presented. C1 Ist Nazl Fis Nucl, I-16146 Genoa, Italy. Univ Genoa, Genoa, Italy. Ist Nazl Fis Nucl, Ferrara, Italy. Univ Ferrara, I-44100 Ferrara, Italy. Ist Nazl Fis Nucl, I-10125 Turin, Italy. Univ Turin, I-10124 Turin, Italy. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Minnesota, Minneapolis, MN 55455 USA. Northwestern Univ, Evanston, IL 60208 USA. Univ Calif Irvine, Irvine, CA USA. RP Patrignani, C (reprint author), Ist Nazl Fis Nucl, Via Dodecaneso 33, I-16146 Genoa, Italy. RI Negrini, Matteo/C-8906-2014; Patrignani, Claudia/C-5223-2009; Messier, Claude/A-2322-2008; Luppi, Eleonora/A-4902-2015; Calabrese, Roberto/G-4405-2015; Lo Vetere, Maurizio/J-5049-2012; Pallavicini, Marco/G-5500-2012 OI Negrini, Matteo/0000-0003-0101-6963; Patrignani, Claudia/0000-0002-5882-1747; Messier, Claude/0000-0002-4791-1763; Luppi, Eleonora/0000-0002-1072-5633; Calabrese, Roberto/0000-0002-1354-5400; Lo Vetere, Maurizio/0000-0002-6520-4480; Pallavicini, Marco/0000-0001-7309-3023 NR 16 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD SEP 10 PY 2001 VL 692 IS 1-2 BP 308C EP 314C PG 7 WC Physics, Nuclear SC Physics GA 474BR UT WOS:000171084900040 ER PT J AU Blansett, EL Raymer, MG Khitrova, G Gibbs, HM Serkland, DK Allerman, AA Geib, KM AF Blansett, EL Raymer, MG Khitrova, G Gibbs, HM Serkland, DK Allerman, AA Geib, KM TI Ultrafast polarization dynamics and noise in pulsed vertical-cavity surface-emitting lasers SO OPTICS EXPRESS LA English DT Article ID SEMICONDUCTOR-LASERS; LIGHT AB We have measured on ps time scales the temporal behavior of the intensity noise of, and correlations between, orthogonally polarized modes in an optically pumped VCSEL. Measurements were made in both the circular and the linear bases. Sub-ps optical pumping with circular polarization leads to positively correlated intensity noise for emission in orthogonal linear polarizations. Optical pumping with linear polarization leads to anti-correlated intensity noise for emission in orthogonal linear polarizations, due to random orientation of linearly polarized emission. Intensity noise for circularly polarized emission is uncorrelated or anti-correlated depending on spin-flip rates which determine the strength of gain competition. We have generalized the theoretical treatment of San Miguel, Feng, and Moloney to successfully model these phenomena. (C) 2001 Optical Society of America. C1 Univ Oregon, Oregon Ctr Opt, Eugene, OR 97403 USA. Univ Oregon, Dept Phys, Eugene, OR 97403 USA. Univ Arizona, Ctr Opt Sci, Tucson, AZ 85721 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Blansett, EL (reprint author), Univ Oregon, Oregon Ctr Opt, Eugene, OR 97403 USA. NR 14 TC 15 Z9 15 U1 0 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD SEP 10 PY 2001 VL 9 IS 6 BP 312 EP 318 PG 7 WC Optics SC Optics GA 473AW UT WOS:000171018000007 PM 19421302 ER PT J AU Alavi-Harati, A Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barbosa, RF Barker, AR Barrio, M Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, C Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Glazov, A Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hamm, J Hanagaki, K Hidaka, S Hsiung, YB Jejer, V Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL Mikelsons, P Monnier, E Nakaya, T Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Quinn, B Qi, XR Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Shields, J Slater, W Solomey, N Somalwar, SV Stone, RL Swallow, EC Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Turner, SE Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Yamanaka, T Zimmerman, ED AF Alavi-Harati, A Alexopoulos, T Arenton, M Arisaka, K Averitte, S Barbosa, RF Barker, AR Barrio, M Bellantoni, L Bellavance, A Belz, J Ben-David, R Bergman, DR Blucher, E Bock, GJ Bown, C Bright, S Cheu, E Childress, S Coleman, R Corcoran, MD Corti, G Cox, B Crisler, MB Erwin, AR Ford, R Glazov, A Golossanov, A Graham, G Graham, J Hagan, K Halkiadakis, E Hamm, J Hanagaki, K Hidaka, S Hsiung, YB Jejer, V Jensen, DA Kessler, R Kobrak, HGE LaDue, J Lath, A Ledovskoy, A McBride, PL Mikelsons, P Monnier, E Nakaya, T Nelson, KS Nguyen, H O'Dell, V Pang, M Pordes, R Prasad, V Quinn, B Qi, XR Ramberg, EJ Ray, RE Roodman, A Sadamoto, M Schnetzer, S Senyo, K Shanahan, P Shawhan, PS Shields, J Slater, W Solomey, N Somalwar, SV Stone, RL Swallow, EC Taegar, SA Tesarek, RJ Thomson, GB Toale, PA Tripathi, A Tschirhart, R Turner, SE Wah, YW Wang, J White, HB Whitmore, J Winstein, B Winston, R Yamanaka, T Zimmerman, ED CA KTev Collaboration TI Branching ratio measurement of the decay K-L -> e(+)e(-)mu(+)mu(-) SO PHYSICAL REVIEW LETTERS LA English DT Article AB We have collected a 43 event sample of the decay K-L --> e(+)e(-)mu (+)mu (-) with negligible backgrounds and measured its branching ratio to be (2.62 +/- 0.40 +/- 0.17) X 10(-9). We see no evidence for CP violation in this decay. In addition, we set the 90% confidence upper limit on the combined branching ratios for the lepton flavor violating decays K-L --> e(+/-)e(+/-)mu (-/+)mu (-/+) at B(K-L --> e(+/-)e(+/-)mu (-/+)mu (-/+)) less than or equal to 1.23 X 10(-10), assuming a uniform phase space distribution. C1 Univ Wisconsin, Madison, WI 53706 USA. Univ Arizona, Tucson, AZ 85721 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Univ Colorado, Boulder, CO 80309 USA. Elmhurst Coll, Elmhurst, IL 60126 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Osaka Univ, Osaka 5600043, Japan. Rice Univ, Houston, TX 77005 USA. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. Univ Virginia, Inst Nucl & Particle Phys, Charlottesville, VA 22901 USA. Univ Sao Paulo, Sao Paulo, Brazil. CNRS, CPP Marseille, Marseille, France. Rutgers State Univ, Piscataway, NJ 08854 USA. RP Lath, A (reprint author), Univ Wisconsin, Madison, WI 53706 USA. NR 8 TC 6 Z9 6 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 10 PY 2001 VL 87 IS 11 BP art. no. EP 111802 DI 10.1103/PhysRevLett.87.111802 PG 5 WC Physics, Multidisciplinary SC Physics GA 472LB UT WOS:000170984600005 PM 11531512 ER PT J AU Bearden, IG Beavis, D Besliu, C Blyakhman, Y Brzychczyk, J Budick, B Boggild, H Chasman, C Christensen, CH Christiansen, P Cibor, J Debbe, R Gaardhoje, JJ Grotowski, K Hagel, K Hansen, O Holm, A Holme, AK Ito, H Jakobsen, E Jipa, A Jordre, JI Jundt, F Jorgensen, CE Keutgen, T Kim, EJ Kozik, T Larsen, TM Lee, JH Lee, YK Lovhoiden, GL Majka, Z Makeev, A McBreen, B Murray, M Natowitz, J Nielsen, BS Olchanski, K Olness, J Ouerdane, D Planeta, R Rami, F Rohrich, D Samset, BH Sanders, SJ Sheetz, RA Sosin, Z Staszel, P Thorsteinsen, TF Tveter, TS Videbaek, F Wada, R Wieloch, A Zgura, IS AF Bearden, IG Beavis, D Besliu, C Blyakhman, Y Brzychczyk, J Budick, B Boggild, H Chasman, C Christensen, CH Christiansen, P Cibor, J Debbe, R Gaardhoje, JJ Grotowski, K Hagel, K Hansen, O Holm, A Holme, AK Ito, H Jakobsen, E Jipa, A Jordre, JI Jundt, F Jorgensen, CE Keutgen, T Kim, EJ Kozik, T Larsen, TM Lee, JH Lee, YK Lovhoiden, GL Majka, Z Makeev, A McBreen, B Murray, M Natowitz, J Nielsen, BS Olchanski, K Olness, J Ouerdane, D Planeta, R Rami, F Rohrich, D Samset, BH Sanders, SJ Sheetz, RA Sosin, Z Staszel, P Thorsteinsen, TF Tveter, TS Videbaek, F Wada, R Wieloch, A Zgura, IS CA BRAHMS Collaboration TI Rapidity dependence of antiproton-to-proton ratios in Au+Au collisions at root s(NN)=130 GeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; MIDRAPIDITY; MODEL AB Measurements, with the BRAHMS detector, of the antiproton-to-proton ratio at midrapidities and forward rapidities, are presented for Au + Au reactions at roots(NN) = 130 GeV, and for three different collision centralities. For collisions in the 0%-40% centrality range, we find N((p) over bar)/N(p) = 0.64 +/- 0.04((stat)) +/- 0.06((syst)) at y approximate to 0, 0.66 +/- 0.03 +/- 0.06 at y approximate to 0.7, and 0.41 +/- 0.04 +/- 0.06 at y approximate to 2. The ratios are found to be nearly independent of collision centrality and transverse momentum. The antiproton and proton rapidity densities vary differently with rapidity, and indicate a significant degree of collision transparency, although a net-baryon free midrapidity plateau (Bjorken limit) is not yet reached. C1 Univ Copenhagen, Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Brookhaven Natl Lab, Upton, NY 11973 USA. Inst Rech Subatom, Strasbourg, France. Univ Strasbourg 1, Strasbourg, France. Inst Nucl Phys, Krakow, Poland. Jagiellonian Univ, Krakow, Poland. Johns Hopkins Univ, Baltimore, MD 21218 USA. NYU, New York, NY 10003 USA. Texas A&M Univ, College Stn, TX 77843 USA. Univ Bergen, Dept Phys, Bergen, Norway. Univ Bucharest, Bucharest, Romania. Univ Kansas, Lawrence, KS 66045 USA. Univ Oslo, Dept Phys, Oslo, Norway. RP Bearden, IG (reprint author), Univ Copenhagen, Niels Bohr Inst, Blegdamsvej 17, DK-2100 Copenhagen, Denmark. RI Christensen, Christian Holm/A-4901-2010; Christensen, Christian/D-6461-2012; Bearden, Ian/M-4504-2014 OI Christensen, Christian Holm/0000-0002-1850-0121; Christensen, Christian/0000-0002-1850-0121; Bearden, Ian/0000-0003-2784-3094 NR 20 TC 64 Z9 64 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 10 PY 2001 VL 87 IS 11 BP art. no. EP 112305 DI 10.1103/PhysRevLett.87.112305 PG 4 WC Physics, Multidisciplinary SC Physics GA 472LB UT WOS:000170984600012 PM 11531519 ER PT J AU Bearden, IG Boggild, H Boissevain, J Christiansen, PHL Conin, L Dodd, J Erazmus, B Esumi, S Fabjan, CW Ferenc, D Franz, A Gaardhoje, JJ Hansen, AG Hansen, O Hardtke, D van Hecke, H Holzer, EB Humanic, TJ Hummel, P Jacak, BV Kaimi, K Kaneta, M Kohama, T Kopytine, M Leltchouk, M Ljubicic, A Lorstad, B Maeda, N Martin, L Medvedev, A Murray, M Ohnishi, H Paic, G Pandey, SU Piuz, F Pluta, J Polychronakos, V Potekhin, M Poulard, G Reichhold, D Sakaguchi, A Schmid-Sorensen, J Simon-Gillo, J Sondheim, W Sugitate, T Sullivan, JP Sumi, Y Willis, WJ Wolf, K Xu, N Zachary, DS AF Bearden, IG Boggild, H Boissevain, J Christiansen, PHL Conin, L Dodd, J Erazmus, B Esumi, S Fabjan, CW Ferenc, D Franz, A Gaardhoje, JJ Hansen, AG Hansen, O Hardtke, D van Hecke, H Holzer, EB Humanic, TJ Hummel, P Jacak, BV Kaimi, K Kaneta, M Kohama, T Kopytine, M Leltchouk, M Ljubicic, A Lorstad, B Maeda, N Martin, L Medvedev, A Murray, M Ohnishi, H Paic, G Pandey, SU Piuz, F Pluta, J Polychronakos, V Potekhin, M Poulard, G Reichhold, D Sakaguchi, A Schmid-Sorensen, J Simon-Gillo, J Sondheim, W Sugitate, T Sullivan, JP Sumi, Y Willis, WJ Wolf, K Xu, N Zachary, DS CA NA44 Collaboration TI Two-kaon correlations in central Pb+Pb collisions at 158 a GeV/c SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; BOSE-EINSTEIN CORRELATIONS; TWISS CORRELATION RADII; QUARK-GLUON PLASMA; PION INTERFEROMETRY; DEPENDENCE; EXPANSION; COHERENCE; CERN AB Two-particle interferometry of positive kaons is studied in Pb + Pb collisions at mean transverse momenta [p(T)] approximate to 0.25 and 0.91 GeV/c. A three-dimensional analysis was applied to the lower p(T) data, while a two-dimensional analysis was used for the higher p(T) data. We find that the source-size parameters are consistent with the m(T) scaling curve observed in pion-correlation measurements in the same collisions. and that the duration time of kaon emission is consistent with zero within the experimental sensitivity. C1 Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Nucl Phys Lab Nantes, F-44072 Nantes, France. Columbia Univ, Dept Phys, New York, NY 10027 USA. Hiroshima Univ, Higashihiroshima 7398526, Japan. CERN, CH-1211 Geneva 23, Switzerland. Rudjer Boskovic Inst, Zagreb, Croatia. Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Lund Univ, Dept Phys, S-22362 Lund, Sweden. Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Bearden, IG (reprint author), Niels Bohr Inst, Blegdamsvej 17, DK-2100 Copenhagen, Denmark. RI Bearden, Ian/M-4504-2014; OI Bearden, Ian/0000-0003-2784-3094; Gaardhoje, Jens-Jorgen/0000-0001-6122-4698 NR 24 TC 31 Z9 33 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 10 PY 2001 VL 87 IS 11 BP art. no. EP 112301 PG 4 WC Physics, Multidisciplinary SC Physics GA 472LB UT WOS:000170984600008 PM 11531515 ER PT J AU Hawkes, NC Stratton, BC Tala, T Challis, CD Conway, G DeAngelis, R Giroud, C Hobirk, J Joffrin, E Lomas, P Lotte, P Mailloux, J Mazon, D Rachlew, E Reyes-Cortes, S Solano, E Zastrow, KD AF Hawkes, NC Stratton, BC Tala, T Challis, CD Conway, G DeAngelis, R Giroud, C Hobirk, J Joffrin, E Lomas, P Lotte, P Mailloux, J Mazon, D Rachlew, E Reyes-Cortes, S Solano, E Zastrow, KD TI Observation of zero current density in the core of JET discharges with lower hybrid heating and current drive SO PHYSICAL REVIEW LETTERS LA English DT Article ID REVERSED MAGNETIC SHEAR; CONFINEMENT; TRANSPORT; TOKAMAKS AB Simultaneous current ramping and application of lower hybrid heating and current drive (LHCD) have produced a region with zero current density within measurement errors in the core (r/a less than or equal to 0.2) of JET tokamak optimized shear discharges. The reduction of core current density is consistent with a simple physical explanation and numerical simulations of radial current diffusion including the effects of LHCD. However, the core current density is clamped at zero, indicating the existence of a physical mechanism which prevents it from becoming negative. C1 UKAEA Euratom Fus Assoc, Culham Sci Ctr, Abingdon OX14 3DB, Oxon, England. Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. Assoc Euratom Tekes, VTT Chem Technol, Espoo, Finland. Max Planck Inst Plasmaphys, EURATOM Assoc, D-85740 Garching, Germany. EURATOM Assoc, ENEA Fus, CRE Frascati, Rome, Italy. CEA Cadarache, EURATOM Assoc, CEA, F-13108 St Paul Durance, France. Royal Inst Technol, Dept Phys 1, Euratom NFR, SE-10044 Stockholm, Sweden. Ctr Fusao Nucl, Euratom IST Assoc, P-1049001 Lisbon, Portugal. CIEMAT, CIEMAT Fus, Assoc EURATOM, E-28040 Madrid, Spain. EFDA CSU JET, Abingdon OX14 3EA, Oxon, England. RP Hawkes, NC (reprint author), UKAEA Euratom Fus Assoc, Culham Sci Ctr, Abingdon OX14 3DB, Oxon, England. RI Solano, Emilia/A-1212-2009 OI Solano, Emilia/0000-0002-4815-3407 NR 17 TC 113 Z9 113 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 10 PY 2001 VL 87 IS 11 BP art. no. EP 115001 DI 10.1103/PhysRevLett.87.115001 PG 4 WC Physics, Multidisciplinary SC Physics GA 472LB UT WOS:000170984600022 PM 11531529 ER PT J AU Murillo, MS AF Murillo, MS TI Using Fermi statistics to create strongly coupled ion plasmas in atom traps SO PHYSICAL REVIEW LETTERS LA English DT Article ID ULTRACOLD NEUTRAL PLASMA; RELAXATION AB We investigate the possibility of forming a strongly coupled ion plasma from a cold atomic gas. We show that rapid ion heating occurs as correlations develop from the initial disordered configuration. This heating severely reduces the Coulomb coupling of the final configuration, although the final Coulomb coupling can be maximized by introducing order into the initial atomic gas. We show that such order can be introduced into the initial state by employing a degenerate Fermi gas whereby the Pauli hole mimics the Coulomb hole. The corresponding initial state correlations can enhance the Coulomb coupling in the final,rate by orders of magnitude. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Murillo, MS (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 12 TC 92 Z9 92 U1 1 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 10 PY 2001 VL 87 IS 11 BP art. no. EP 115003 DI 10.1103/PhysRevLett.87.115003 PG 4 WC Physics, Multidisciplinary SC Physics GA 472LB UT WOS:000170984600024 PM 11531531 ER PT J AU Nam, MS Ardavan, A Symington, JA Singleton, J Harrison, N Mielke, CH Schlueter, JA Winter, RW Gard, GL AF Nam, MS Ardavan, A Symington, JA Singleton, J Harrison, N Mielke, CH Schlueter, JA Winter, RW Gard, GL TI Thermal activation between Landau levels in the organic superconductor beta ''-(BEDT-TTF)(2)SF5CH2CF2SO3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH MAGNETIC-FIELDS; CHARGE-DENSITY-WAVE; FERMI-SURFACE; BEDT-TTF; MAGNETORESISTANCE; SALT; OSCILLATIONS; LOCALIZATION; CONDUCTOR; STATES AB We show that Shubnikov-de Haas oscillations in the interlayer resistivity of the organic superconductor beta"-(BEDT-TTF)(2)SF5CH2CF2SO3 become very pronounced in magnetic fields similar to 60 T. The conductivity minima exhibit thermally activated behavior that can be explained simply by the presence of a Landau gap, with the quasi-one-dimensional Fermi surface sheets contributing negligibly to the conductivity. This observation, together with complete suppression of chemical potential oscillations, is consistent with an incommensurate nesting instability of the quasi-one-dimensional sheets. C1 Univ Oxford, Dept Phys, Clarendon Lab, Oxford OX1 3PU, England. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Argonne Natl Lab, Div Chem & Mat Sci, Argonne, IL 60439 USA. Portland State Univ, Dept Chem, Portland, OR 97207 USA. RP Nam, MS (reprint author), Univ Oxford, Dept Phys, Clarendon Lab, Parks Rd, Oxford OX1 3PU, England. NR 23 TC 25 Z9 25 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 10 PY 2001 VL 87 IS 11 BP art. no. EP 117001 DI 10.1103/PhysRevLett.87.117001 PG 4 WC Physics, Multidisciplinary SC Physics GA 472LB UT WOS:000170984600037 PM 11531544 ER PT J AU Adler, C Ahammed, Z Allgower, C Amonett, J Anderson, BD Anderson, M Averichev, GS Balewski, J Barannikova, O Barnby, LS Baudot, J Bekele, S Belaga, VV Bellwied, R Berger, J Bichsel, H Bland, LC Blyth, CO Bonner, BE Bossingham, R Boucham, A Brandin, A Caines, H Sanchez, MCD Cardenas, A Carroll, J Castillo, J Castro, M Cebra, D Chattopadhyay, S Chen, ML Chen, Y Chernenko, SP Cherney, M Chikanian, A Choi, B Christie, W Coffin, JP Conin, L Cormier, TM Cramer, JG Crawford, HJ DeMello, M Deng, WS Derevschikov, AA Didenko, L Draper, JE Dunin, VB Dunlop, JC Eckardt, V Efimov, LG Emelianov, V Engelage, J Eppley, G Erazmus, B Fachini, P Finch, E Fisyak, Y Flierl, D Foley, KJ Fu, J Gagunashvili, N Gans, J Gaudichet, L Germain, M Geurts, F Ghazikhanian, V Grabski, J Grachov, O Greiner, D Grigoriev, V Guedon, M Gushin, E Hallman, TJ Hardtke, D Harris, JW Heffner, M Heppelmann, S Herston, T Hippolyte, B Hirsch, A Hjort, E Hoffmann, GW Horsley, M Huang, HZ Humanic, TJ Hummler, H Igo, G Ishihara, A Ivanshin, YI Jacobs, P Jacobs, WW Janik, M Johnson, I Jones, PG Judd, E Kaneta, M Kaplan, M Keane, D Kisiel, A Klay, J Klein, SR Klyachko, A Konstantinov, AS Kotchenda, L Kovalenko, AD Kramer, M Kravtsov, P Krueger, K Kuhn, C Kulikov, AI Kunde, GJ Kunz, CL Kutuev, RK Kuznetsov, AA Lakehal-Ayat, L Lamas-Valverde, J Lamont, MAC Landgraf, JM Lange, S Lansdell, CP Lasiuk, B Laue, F Lebedev, A LeCompte, T Lednicky, R Leontiev, VM Leszczynski, P LeVine, MJ Li, Q Li, Q Lindenbaum, SJ Lisa, MA Ljubicic, T Llope, WJ LoCurto, G Long, H Longacre, RS Lopez-Noriega, M Love, WA Lynn, D Majka, R Maliszewski, A Margetis, S Martin, L Marx, J Matis, HS Matulenko, YA McShane, TS Meissner, F Melnick, Y Meschanin, A Messer, M Miller, ML Milosevich, Z Minaev, NG Mitchell, J Moiseenko, VA Moltz, D Moore, CF Morozov, V de Moura, MM Munhoz, MG Mutchler, GS Nelson, JM Nevski, P Nikitin, VA Nogach, LV Norman, B Nurushev, SB Odyniec, G Ogawa, A Okorokov, V Oldenburg, M Olson, D Paic, G Pandey, SU Panebratsev, Y Panitkin, SY Pavlinov, AI Pawlak, T Perevoztchikov, V Peryt, W Petrov, VA Pinganaud, W Platner, E Pluta, J Porile, N Porter, J Poskanzer, AM Potrebenikova, E Prindle, D Pruneau, C Radomski, S Rai, G Ravel, O Ray, RL Razin, SV Reichhold, D Reid, JG Retiere, F Ridiger, A Ritter, HG Roberts, JB Rogachevski, OV Romero, JL Roy, C Russ, D Rykov, V Sakrejda, I Sandweiss, J Saulys, AC Savin, I Schambach, J Scharenberg, RP Schweda, K Schmitz, N Schroeder, LS Schuttauf, A Seger, J Seliverstov, D Seyboth, P Shahaliev, E Shestermanov, KE Shimanskii, SS Shvetcov, VS Skoro, G Smirnov, N Snellings, R Sowinski, J Spinka, HM Srivastava, B Stephenson, EJ Stock, R Stolpovsky, A Strikhanov, M Stringfellow, B Stroebele, H Struck, C Suaide, AAP Sugarbaker, E Suire, C Sumbera, M Symons, TJM de Toledo, AS Szarwas, P Takahashi, J Tang, AH Thomas, JH Tikhomirov, V Trainor, TA Trentalange, S Tokarev, M Tonjes, MB Trofimov, V Tsai, O Turner, K Ullrich, T Underwood, DG Van Buren, G VanderMolen, AM Vanyashin, A Vasilevski, IM Vasiliev, AN Vigdor, SE Voloshin, SA Wang, F Ward, H Watson, JW Wells, R Wenaus, T Westfall, GD Whitten, C Wieman, H Willson, R Wissink, SW Witt, R Xu, N Xu, Z Yakutin, AE Yamamoto, E Yang, J Yepes, P Yokosawa, A Yurevich, VI Zanevski, YV Zborovsky, I Zhang, YM Zoulkarneev, R Zubarev, AN AF Adler, C Ahammed, Z Allgower, C Amonett, J Anderson, BD Anderson, M Averichev, GS Balewski, J Barannikova, O Barnby, LS Baudot, J Bekele, S Belaga, VV Bellwied, R Berger, J Bichsel, H Bland, LC Blyth, CO Bonner, BE Bossingham, R Boucham, A Brandin, A Caines, H Sanchez, MCD Cardenas, A Carroll, J Castillo, J Castro, M Cebra, D Chattopadhyay, S Chen, ML Chen, Y Chernenko, SP Cherney, M Chikanian, A Choi, B Christie, W Coffin, JP Conin, L Cormier, TM Cramer, JG Crawford, HJ DeMello, M Deng, WS Derevschikov, AA Didenko, L Draper, JE Dunin, VB Dunlop, JC Eckardt, V Efimov, LG Emelianov, V Engelage, J Eppley, G Erazmus, B Fachini, P Finch, E Fisyak, Y Flierl, D Foley, KJ Fu, J Gagunashvili, N Gans, J Gaudichet, L Germain, M Geurts, F Ghazikhanian, V Grabski, J Grachov, O Greiner, D Grigoriev, V Guedon, M Gushin, E Hallman, TJ Hardtke, D Harris, JW Heffner, M Heppelmann, S Herston, T Hippolyte, B Hirsch, A Hjort, E Hoffmann, GW Horsley, M Huang, HZ Humanic, TJ Hummler, H Igo, G Ishihara, A Ivanshin, YI Jacobs, P Jacobs, WW Janik, M Johnson, I Jones, PG Judd, E Kaneta, M Kaplan, M Keane, D Kisiel, A Klay, J Klein, SR Klyachko, A Konstantinov, AS Kotchenda, L Kovalenko, AD Kramer, M Kravtsov, P Krueger, K Kuhn, C Kulikov, AI Kunde, GJ Kunz, CL Kutuev, RK Kuznetsov, AA Lakehal-Ayat, L Lamas-Valverde, J Lamont, MAC Landgraf, JM Lange, S Lansdell, CP Lasiuk, B Laue, F Lebedev, A LeCompte, T Lednicky, R Leontiev, VM Leszczynski, P LeVine, MJ Li, Q Li, Q Lindenbaum, SJ Lisa, MA Ljubicic, T Llope, WJ LoCurto, G Long, H Longacre, RS Lopez-Noriega, M Love, WA Lynn, D Majka, R Maliszewski, A Margetis, S Martin, L Marx, J Matis, HS Matulenko, YA McShane, TS Meissner, F Melnick, Y Meschanin, A Messer, M Miller, ML Milosevich, Z Minaev, NG Mitchell, J Moiseenko, VA Moltz, D Moore, CF Morozov, V de Moura, MM Munhoz, MG Mutchler, GS Nelson, JM Nevski, P Nikitin, VA Nogach, LV Norman, B Nurushev, SB Odyniec, G Ogawa, A Okorokov, V Oldenburg, M Olson, D Paic, G Pandey, SU Panebratsev, Y Panitkin, SY Pavlinov, AI Pawlak, T Perevoztchikov, V Peryt, W Petrov, VA Pinganaud, W Platner, E Pluta, J Porile, N Porter, J Poskanzer, AM Potrebenikova, E Prindle, D Pruneau, C Radomski, S Rai, G Ravel, O Ray, RL Razin, SV Reichhold, D Reid, JG Retiere, F Ridiger, A Ritter, HG Roberts, JB Rogachevski, OV Romero, JL Roy, C Russ, D Rykov, V Sakrejda, I Sandweiss, J Saulys, AC Savin, I Schambach, J Scharenberg, RP Schweda, K Schmitz, N Schroeder, LS Schuttauf, A Seger, J Seliverstov, D Seyboth, P Shahaliev, E Shestermanov, KE Shimanskii, SS Shvetcov, VS Skoro, G Smirnov, N Snellings, R Sowinski, J Spinka, HM Srivastava, B Stephenson, EJ Stock, R Stolpovsky, A Strikhanov, M Stringfellow, B Stroebele, H Struck, C Suaide, AAP Sugarbaker, E Suire, C Sumbera, M Symons, TJM de Toledo, AS Szarwas, P Takahashi, J Tang, AH Thomas, JH Tikhomirov, V Trainor, TA Trentalange, S Tokarev, M Tonjes, MB Trofimov, V Tsai, O Turner, K Ullrich, T Underwood, DG Van Buren, G VanderMolen, AM Vanyashin, A Vasilevski, IM Vasiliev, AN Vigdor, SE Voloshin, SA Wang, F Ward, H Watson, JW Wells, R Wenaus, T Westfall, GD Whitten, C Wieman, H Willson, R Wissink, SW Witt, R Xu, N Xu, Z Yakutin, AE Yamamoto, E Yang, J Yepes, P Yokosawa, A Yurevich, VI Zanevski, YV Zborovsky, I Zhang, YM Zoulkarneev, R Zubarev, AN CA STAR Collaboration TI Multiplicity distribution and spectra of negatively charged hadrons in Au+Au collisions at root s(NN)=130 GeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; 0.9 TEV; ENERGY; QUARK AB The minimum-bias multiplicity distribution and the transverse momentum and pseudorapidity distributions for central collisions have been measured for negative hadrons (h(-)) in Au + Au interactions at roots(NN) = 130 GeV. The multiplicity density at midrapidity for the 5% most central interactions is dN(h)-/d eta\(eta =0) = 280 +/- (stat) +/- 20(syst), an increase per participant of 38% relative to p (p) over bar collisions at the same energy. The mean transverse momentum is 0.508 +/- 0.012 GcV/c and is larger than in central Pb + Pb collisions at lower energies. The scaling of the h(-) yield per participant is a strong function of p(perpendicular to). The pseudorapidity distribution is almost constant within \eta\ < 1. C1 Univ Frankfurt, D-6000 Frankfurt, Germany. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Birmingham, Birmingham, W Midlands, England. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Los Angeles, Los Angeles, CA 90095 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Creighton Univ, Omaha, NE 68178 USA. Joint Inst Nucl Res Dubna, Lab High Energy, Dubna, Russia. Joint Inst Nucl Res Dubna, Particle Phys Lab, Dubna, Russia. Indiana Univ, Bloomington, IN 47408 USA. Inst Rech Subatom, Strasbourg, France. Kent State Univ, Kent, OH 44242 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Max Planck Inst Phys & Astrophys, D-80805 Munich, Germany. Michigan State Univ, E Lansing, MI 48824 USA. Moscow Engn Phys Inst, Moscow 115409, Russia. CUNY City Coll, New York, NY 10031 USA. Ohio State Univ, Columbus, OH 43210 USA. Penn State Univ, University Pk, PA 16802 USA. Inst High Energy Phys, Protvino, Russia. Purdue Univ, W Lafayette, IN 47907 USA. Rice Univ, Houston, TX 77251 USA. Univ Sao Paulo, Sao Paulo, Brazil. SUBATECH, Nantes, France. Univ Texas, Austin, TX 78712 USA. Warsaw Univ Technol, Warsaw, Poland. Univ Washington, Seattle, WA 98195 USA. Wayne State Univ, Detroit, MI 48201 USA. Yale Univ, New Haven, CT 06520 USA. Argonne Natl Lab, Argonne, IL 60439 USA. RP Adler, C (reprint author), Univ Frankfurt, D-6000 Frankfurt, Germany. RI Strikhanov, Mikhail/P-7393-2014; Kisiel, Adam/O-8754-2015; Tikhomirov, Vladimir/M-6194-2015; Suaide, Alexandre/L-6239-2016; Okorokov, Vitaly/C-4800-2017; Sumbera, Michal/O-7497-2014; Skoro, Goran/P-1229-2014; Skoro, Goran/F-3642-2010; Barnby, Lee/G-2135-2010; Takahashi, Jun/B-2946-2012; Chen, Yu/E-3788-2012; Witt, Richard/H-3560-2012; Castillo Castellanos, Javier/G-8915-2013; Vanyashin, Aleksandr/H-7796-2013; Voloshin, Sergei/I-4122-2013; Johnson, Ian/I-2439-2013; Lednicky, Richard/K-4164-2013; Zborovsky, Imrich/G-7964-2014 OI Strikhanov, Mikhail/0000-0003-2586-0405; Kisiel, Adam/0000-0001-8322-9510; Tikhomirov, Vladimir/0000-0002-9634-0581; Suaide, Alexandre/0000-0003-2847-6556; Okorokov, Vitaly/0000-0002-7162-5345; Sumbera, Michal/0000-0002-0639-7323; Skoro, Goran/0000-0001-7745-9045; Barnby, Lee/0000-0001-7357-9904; Takahashi, Jun/0000-0002-4091-1779; Castillo Castellanos, Javier/0000-0002-5187-2779; Vanyashin, Aleksandr/0000-0002-0367-5666; NR 24 TC 173 Z9 173 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 10 PY 2001 VL 87 IS 11 AR 112303 DI 10.1103/PhysRevLett.87.112303 PG 5 WC Physics, Multidisciplinary SC Physics GA 472LB UT WOS:000170984600010 PM 11531517 ER PT J AU Belkin, MA Han, SH Wei, X Shen, YR AF Belkin, MA Han, SH Wei, X Shen, YR TI Sum-frequency generation in chiral liquids near electronic resonance SO PHYSICAL REVIEW LETTERS LA English DT Article ID SURFACE 2ND-HARMONIC GENERATION; CIRCULAR-DICHROISM SPECTROSCOPY; 2ND HARMONIC-GENERATION; VIBRATIONAL SPECTROSCOPY; MOLECULAR CHIRALITY AB We demonstrate experimentally that visible-visible sum-frequency generation in the bulk of a chiral liquid is observable near electronic resonant transitions. Although the process is electric dipole allowed. it is rather weak because the orientational average over molecules effectively reduces the bulk chiral nonlinearity. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Shen, YR (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Belkin, Mikhail/E-9041-2013 OI Belkin, Mikhail/0000-0003-3172-9462 NR 12 TC 87 Z9 87 U1 1 U2 26 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 10 PY 2001 VL 87 IS 11 AR 113001 DI 10.1103/PhysRevLett.87.113001 PG 4 WC Physics, Multidisciplinary SC Physics GA 472LB UT WOS:000170984600013 PM 11531520 ER PT J AU Chuang, YD Gromko, AD Fedorov, A Aiura, Y Oka, K Ando, Y Eisaki, H Uchida, SI Dessau, DS AF Chuang, YD Gromko, AD Fedorov, A Aiura, Y Oka, K Ando, Y Eisaki, H Uchida, SI Dessau, DS TI Doubling of the bands in overdoped Bi2Sr2CaCu2O8+delta: Evidence for c-axis bilayer coupling SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMI-SURFACE; ELECTRONIC-STRUCTURE; PHOTOEMISSION AB We present high resolution angle resolved photoemission data of the bilayer superconductor Bi2Sr2CaCu2O8+delta (Bi2212) showing a clear doubling of the near E-F bands. This splitting approaches zero along the (0, 0) - (pi, pi) nodal line and is not observed in single layer Bi2Sr2CuO6+delta (Bi2201), indicating that the splitting is due to the long sought after bilayer splitting effect. The splitting has a magnitude of approximately 75 meV near the middle of the zone, extrapolating to about 110 meV near the (pi, 0) point. The existence of these two bands also helps to clear up the recent controversy concerning the topology of the Fermi surface. C1 Univ Colorado, Dept Phys, Boulder, CO 80309 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Electrotech Lab, Tsukuba, Ibaraki 3058568, Japan. Cent Res Inst Elect Power Ind, Tokyo 2018511, Japan. Univ Tokyo, Dept Superconduct, Bunkyo Ku, Tokyo 113, Japan. RP Chuang, YD (reprint author), Univ Colorado, Dept Phys, Boulder, CO 80309 USA. RI Ando, Yoichi/B-8163-2013 OI Ando, Yoichi/0000-0002-3553-3355 NR 22 TC 106 Z9 107 U1 1 U2 14 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 10 PY 2001 VL 87 IS 11 AR 117002 DI 10.1103/PhysRevLett.87.117002 PG 4 WC Physics, Multidisciplinary SC Physics GA 472LB UT WOS:000170984600038 PM 11531545 ER PT J AU Panitkin, SY Ajitanand, NN Alexander, J Anderson, M Best, D Brady, FP Case, T Caskey, W Cebra, D Chance, J Chung, P Cole, B Crowe, K Das, A Draper, J Gilkes, M Gushue, S Heffner, M Hirsch, A Hjort, E Huo, L Justice, M Kaplan, M Keane, D Kintner, J Klay, J Krofcheck, D Lacey, R Lauret, J Lisa, MA Liu, H Liu, YM McGrath, R Milosevich, Z Odyniec, G Olson, D Pinkenburg, C Porile, N Rai, G Ritter, HG Romero, J Scharenberg, R Schroeder, LS Srivastava, B Stone, NTB Symon, TJM Wang, S Wells, R Whitfield, J Wienold, T Witt, R Wood, L Yang, X Zhang, WN Zhang, Y AF Panitkin, SY Ajitanand, NN Alexander, J Anderson, M Best, D Brady, FP Case, T Caskey, W Cebra, D Chance, J Chung, P Cole, B Crowe, K Das, A Draper, J Gilkes, M Gushue, S Heffner, M Hirsch, A Hjort, E Huo, L Justice, M Kaplan, M Keane, D Kintner, J Klay, J Krofcheck, D Lacey, R Lauret, J Lisa, MA Liu, H Liu, YM McGrath, R Milosevich, Z Odyniec, G Olson, D Pinkenburg, C Porile, N Rai, G Ritter, HG Romero, J Scharenberg, R Schroeder, LS Srivastava, B Stone, NTB Symon, TJM Wang, S Wells, R Whitfield, J Wienold, T Witt, R Wood, L Yang, X Zhang, WN Zhang, Y CA E895 Collaboration TI Model-independent source imaging using two-pion correlations in (2 to 8)A GeVAu+Au collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; INTERFEROMETRY AB We report a particle source imaging analysis based on two-pion correlations in high multiplicity Au+Au collisions at beam energies between 2A and 8A GeV. We apply the imaging technique introduced by Brown and Danielewicz, which allows a model-independent extraction of source functions with useful accuracy out to relative pion separations of about 20 fm. The extracted source functions have Gaussian shapes. Values of source functions at zero separation are almost constant across the energy range under study. Imaging results are found to be consistent with conventional source parameters obtained from a multidimensional Hanburg-Brown-Twiss analysis. C1 Kent State Univ, Kent, OH 44242 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Columbia Univ, New York, NY 10027 USA. Univ Calif Davis, Davis, CA 95616 USA. Harbin Inst Technol, Harbin 150001, Peoples R China. St Marys Coll, Moraga, CA 94575 USA. Univ Auckland, Auckland 1, New Zealand. Ohio State Univ, Columbus, OH 43210 USA. Purdue Univ, W Lafayette, IN 47907 USA. SUNY Stony Brook, Stony Brook, NY 11794 USA. Univ Washington, Seattle, WA 98195 USA. Michigan State Univ, E Lansing, MI 48824 USA. RP Panitkin, SY (reprint author), Kent State Univ, Kent, OH 44242 USA. RI Witt, Richard/H-3560-2012 NR 22 TC 16 Z9 18 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 10 PY 2001 VL 87 IS 11 AR 112304 DI 10.1103/PhysRevLett.87.112304 PG 5 WC Physics, Multidisciplinary SC Physics GA 472LB UT WOS:000170984600011 PM 11531518 ER PT J AU Rodriguez, JA Dvorak, J Jirsak, T Hrbek, J AF Rodriguez, JA Dvorak, J Jirsak, T Hrbek, J TI Formation of Mo and MoSx nanoparticles on Au(111) from Mo(CO)(6) and S-2 precursors: electronic and chemical properties SO SURFACE SCIENCE LA English DT Article DE carbon monoxide; gold; molybdenum; sulphides; sulphur; surface chemical reaction; synchrotron radiation photoelectron spectroscopy ID CHARGE REDISTRIBUTION; THERMAL-DECOMPOSITION; SURFACE-CHEMISTRY; VAPOR-DEPOSITION; NI(100) SURFACES; ADSORPTION; THIOPHENE; SULFUR; BEHAVIOR; FILMS AB Mo(CO)(6) can be useful as a precursor for the preparation of Mo and MoSx nanoparticles on a Au(1 1 1) substrate. On this surface the carbonyl adsorbs intact at 100 K and desorbs at temperatures lower than 300 K. Under these conditions, the dissociation of the Mo(CO)(6) molecule is negligible and a desorption channel clearly dominates. An efficient dissociation channel was found after dosing Mo(CO)(6) at high temperatures (> 400 K). The decomposition of Mo(CO)(6) yields the small coverages of pure Mo that are necessary for the formation of Mo nanoclusters on the Au(1 1 1) substrate. At large coverages of Mo (>0.15 ML), the dissociation of Mo(CO)(6) produces also C and O ad-atoms. Mo nanoclusters bonded to Au(1 1 1) exhibit a surprising low reactivity towards CO. Mo/Au(1 1 1) surfaces with Mo coverages below 0.1 ML adsorb the CO molecule weakly (desorption temperature < 400 K) and do not induce C-O bond cleavage. These systems, however, are able to induce the dissociation of thiophene at temperatures below 300 K and react with sulfur probably to form MoSx nanoparticles. The formed MoSx species are more reactive towards thiophene than extended MoS2(0 0 0 2) surfaces, MoSx films or MoSX/Al2O3 catalysts. This could be a consequence of special adsorption sites and/or distinctive electronic properties that favor bonding interactions with sulfur-containing molecules. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Bldg 555,POB 5000, Upton, NY 11973 USA. RI Hrbek, Jan/I-1020-2013 NR 63 TC 37 Z9 37 U1 1 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 10 PY 2001 VL 490 IS 3 BP 315 EP 326 DI 10.1016/S0039-6028(01)01347-4 PG 12 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 473XW UT WOS:000171075300014 ER PT J AU Abramowski, M Redfern, SE Grimes, RW Owens, S AF Abramowski, M Redfern, SE Grimes, RW Owens, S TI Modification of UO2 crystal morphologies through hydroxylation SO SURFACE SCIENCE LA English DT Article DE computer simulations; surface structure, morphology, roughness and topography; uranium oxide; single crystal surfaces; surface defects ID TZP AB Atomic scale computer simulation is used to predict the surface energies Of UO2, subject to different hydroxide coverages. It was found that the {111} surface dominates dry UO2, resulting in an octahedral morphology. However, the {100} surfaces were strongly stabilized by hydroxylation relative to the {111} surfaces. Consequently, even a modest hydroxylation of 30% substantially truncates the octahedron crystal morphology, and a fully cubic morphology is predicted at 80% hydroxide coverage. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ London Imperial Coll Sci Technol & Med, Dept Mat Sci, London SW7 2BP, England. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. BNFL, Res & Technol, Warrington WA3 6AS, Cheshire, England. RP Grimes, RW (reprint author), Univ London Imperial Coll Sci Technol & Med, Dept Mat Sci, Consort Rd, London SW7 2BP, England. NR 13 TC 24 Z9 24 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD SEP 10 PY 2001 VL 490 IS 3 BP 415 EP 420 DI 10.1016/S0039-6028(01)01368-1 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 473XW UT WOS:000171075300023 ER PT J AU Shroll, RM Lohr, LL Barker, JR AF Shroll, RM Lohr, LL Barker, JR TI Empirical potentials for rovibrational energy transfer of hydrogen fluoride in collisions with argon SO JOURNAL OF CHEMICAL PHYSICS LA English DT Review ID NONLOCAL THERMODYNAMIC-EQUILIBRIUM; CORRELATED MOLECULAR CALCULATIONS; COUPLED STATES APPROXIMATION; AB-INITIO CALCULATIONS; GAUSSIAN-BASIS SETS; ANISOTROPIC INTERMOLECULAR FORCES; ROTATIONALLY INELASTIC-COLLISIONS; HIGH-RESOLUTION SPECTROSCOPY; ANGULAR-MOMENTUM TRANSFER; DER-WAALS MOLECULES AB Rovibrational energy transfer of hydrogen fluoride in collisions with argon was investigated by using the coupled-states approximation to the quantum scattering problem. Empirically determined 3-D ab initio potential energy surfaces (PES) for the interaction between hydrogen fluoride and argon are presented. Second-order Moller-Plesset perturbation theory (MP2) was used to provide an initial approximate PES for the complex. The MP2 PES was subsequently modified to compensate for the underestimated dispersion interaction and adjusted until the desired agreement between calculated and observed spectroscopic quantities was achieved. Calculated rotational cross sections are in good agreement with experimental results as well as those obtained with a highly accurate vibrationally averaged empirical PES [J. M. Hutson, J. Chem. Phys. 96, 6752 (1992)]. The rate constants for the collision induced relaxation of the first vibrational state of hydrogen fluoride are presented as functions of temperature. The rate constants show structure at low temperature corresponding to cross-section resonances. The calculated rate constants are in good agreement with available high temperature experimental results. The calculations provide lower temperature rate constants and a wealth of detailed state-to-state information that are not available from experiment. (C) 2001 American Institute of Physics. C1 Univ Michigan, Dept Chem, Ann Arbor, MI 48109 USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. RP Shroll, RM (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Computat Biochem Biophys & Biol Grp, Richland, WA 99352 USA. RI Barker, John/F-5904-2012 OI Barker, John/0000-0001-9248-2470 NR 130 TC 10 Z9 11 U1 3 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 2001 VL 115 IS 10 BP 4573 EP 4585 DI 10.1063/1.1388547 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 466LT UT WOS:000170647600020 ER PT J AU Taylor, TR Gomez, H Asmis, KR Neumark, DM AF Taylor, TR Gomez, H Asmis, KR Neumark, DM TI Photoelectron spectroscopy of GaX2-, Ga2X-, Ga2X2-, and Ga2X3-(X=P,As) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GALLIUM-ARSENIDE CLUSTERS; POTENTIAL-ENERGY CURVES; SMALL GAAS CLUSTERS; ELECTRONIC-STRUCTURE; BASIS-SETS; AB-INITIO; STATES; SPECTRA; IONS; PHOSPHIDE AB Anion photoelectron spectra taken at various photodetachment wavelengths have been obtained for GaX2-, Ga2X-, Ga2X2-, and Ga2X3- (X=P,As). The incorporation of a liquid nitrogen cooled channel in the ion source resulted in substantial vibrational cooling of the cluster anions, resulting in resolved vibrational progressions in the photoelectron spectra of all species except Ga2X2-. Electron affinities, electronic term values, and vibrational frequencies are reported and compared to electronic structure calculations. In addition, similarities and differences between the phosphorus and arsenic-containing isovalent species are discussed. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Free Univ Berlin, Fachbereich Phys, Inst Phys Expt, D-14195 Berlin, Germany. RP Taylor, TR (reprint author), 47131 Bayside Pkwy, Fremont, CA 94538 USA. RI Neumark, Daniel/B-9551-2009; Asmis, Knut/N-5408-2014 OI Neumark, Daniel/0000-0002-3762-9473; Asmis, Knut/0000-0001-6297-5856 NR 51 TC 67 Z9 69 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 2001 VL 115 IS 10 BP 4620 EP 4631 DI 10.1063/1.1391267 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 466LT UT WOS:000170647600025 ER PT J AU Bright, JN Stevens, MJ Hoh, J Woolf, TB AF Bright, JN Stevens, MJ Hoh, J Woolf, TB TI Characterizing the function of unstructured proteins: Simulations of charged polymers under confinement SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS; POLYAMPHOLYTES; CHAIN; POLYELECTROLYTES; CONFORMATIONS; MECHANISM; PARTICLES; BRUSHES; FORCES; WALLS AB Experimental findings that some polypeptides may be unstructured and behave as entropically driven polymeric spacers in biological systems motivates a study of confined polymers. Here we examine the confinement of neutral, polyampholyte, and polyelectrolyte polymers between two parallel surfaces using course grained models and molecular dynamics. Forces between the confining surfaces are determined for different polymer classes and as a function of chain length, charge sequence (pattern) and degree of confinement. Changes in chain properties are also evaluated under these conditions. The results reinforce the significance of length and net charge for predicting chain properties. In addition the clustering of charge along the chain appears to be critical, and changes in cluster size and distribution produce dramatic changes in chain behavior. (C) 2001 American Institute of Physics. C1 Johns Hopkins Univ, Sch Med, Dept Physiol, Baltimore, MD 21205 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Bright, JN (reprint author), Johns Hopkins Univ, Sch Med, Dept Physiol, Baltimore, MD 21205 USA. OI Hoh, Jan/0000-0003-3842-9454 NR 51 TC 16 Z9 17 U1 1 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 8 PY 2001 VL 115 IS 10 BP 4909 EP 4918 DI 10.1063/1.1392361 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 466LT UT WOS:000170647600055 ER PT J AU Coe, BJ Harris, JA Clays, K Persoons, A Wostyn, K Brunschwig, BS AF Coe, BJ Harris, JA Clays, K Persoons, A Wostyn, K Brunschwig, BS TI A comparison of the pentaammine(pyridyl)ruthenium(II) and 4-(dimethylamino)phenyl groups as electron donors for quadratic non-linear optics SO CHEMICAL COMMUNICATIONS LA English DT Article ID HYPER-RAYLEIGH SCATTERING; HIGH-FREQUENCY DEMODULATION; MULTIPHOTON FLUORESCENCE; COMPLEXES; HYPERPOLARIZABILITIES; SPECTROSCOPY; CHROMOPHORES AB Hyper-Rayleigh scattering and Stark spectroscopic studies show that the complex salts [1-4]PF6 have larger static first hyperpolarizabilities beta (0) than [5-8]PF6, because the higher HOMO energy of a {Ru-II(NH3)(5)}(2+) centre more than offsets the superior pi -orbital overlap in the purely organic chromophores. C1 Univ Manchester, Dept Chem, Manchester M13 9PL, Lancs, England. Univ Louvain, Dept Chem, B-3001 Louvain, Belgium. Univ Arizona, Ctr Opt Sci, Tucson, AZ 85721 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Coe, BJ (reprint author), Univ Manchester, Dept Chem, Oxford Rd, Manchester M13 9PL, Lancs, England. RI Brunschwig, Bruce/G-4249-2011 NR 18 TC 32 Z9 32 U1 1 U2 6 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD SEP 7 PY 2001 IS 17 BP 1548 EP 1549 DI 10.1039/b103543f PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 469DQ UT WOS:000170798800008 PM 12240375 ER PT J AU Kavallieratos, K Moyer, BA AF Kavallieratos, K Moyer, BA TI Attenuation of Hofmeister bias in ion-pair extraction by a disulfonamide anion host used in strikingly effective synergistic combination with a calix-crown Cs+ host SO CHEMICAL COMMUNICATIONS LA English DT Article ID 1,2-DICHLOROETHANE; RECOGNITION; DERIVATIVES; RECEPTORS; TRANSPORT; VERSATILE; BINDING; NITRATE AB A calix-crown/disulfonamide dual-host combination in 1,2-dichloroethane exhibits markedly enhanced ion-pair extraction of caesium salts, with the observed synergism following an anti-Hofmeister order. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Chem Separat Grp, Oak Ridge, TN 37831 USA. RP Moyer, BA (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Chem Separat Grp, Bldg 4500S,MS-6119,POB 2008, Oak Ridge, TN 37831 USA. RI Solominow, Sonia/A-4021-2008; Moyer, Bruce/L-2744-2016 OI Moyer, Bruce/0000-0001-7484-6277 NR 21 TC 56 Z9 56 U1 0 U2 5 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD SEP 7 PY 2001 IS 17 BP 1620 EP 1621 DI 10.1039/b102152b PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 469DQ UT WOS:000170798800044 PM 12240411 ER PT J AU Barnum, H Caves, CM Fuchs, CA Jozsa, R Schumacher, B AF Barnum, H Caves, CM Fuchs, CA Jozsa, R Schumacher, B TI On quantum coding for ensembles of mixed states SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID CLASSICAL INFORMATION; ENTROPY; CHANNEL AB We consider the problem of optimal asymptotically faithful compression for ensembles of mixed quantum states. Although the optimal rate is unknown, we prove upper and lower bounds and describe a series of illustrative examples of compression of mixed states. We also discuss a classical analogue of the problem. C1 Univ Bristol, Dept Comp Sci, Bristol BS8 1UB, Avon, England. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Kenyon Coll, Dept Phys, Gambier, OH 43022 USA. RP Barnum, H (reprint author), Univ Bristol, Dept Comp Sci, Merchant Venturers Bldg, Bristol BS8 1UB, Avon, England. RI Caves, Carlton/K-8167-2014 OI Caves, Carlton/0000-0001-8876-1186 NR 30 TC 14 Z9 14 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD SEP 7 PY 2001 VL 34 IS 35 BP 6767 EP 6785 DI 10.1088/0305-4470/34/35/304 PG 19 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 481VG UT WOS:000171540700005 ER PT J AU Viola, L Knill, E Laflamme, R AF Viola, L Knill, E Laflamme, R TI Constructing qubits in physical systems SO JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL LA English DT Article ID UNIVERSAL QUANTUM COMPUTATION; CHANNELS; CODES AB The notion of a qubit is ubiquitous in quantum information processing. In spite of the simple abstract definition of qubits as two-state quantum systems, identifying qubits; in physical systems is often unexpectedly difficult. There is an astonishing variety of ways in which qubits can emerge from devices. What essential features are required for an implementation to properly instantiate a qubit? We give three typical examples and propose an operational characterization of qubits based on quantum observables and subsystems. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Viola, L (reprint author), Los Alamos Natl Lab, MS B265, Los Alamos, NM 87545 USA. NR 41 TC 36 Z9 37 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0305-4470 J9 J PHYS A-MATH GEN JI J. Phys. A-Math. Gen. PD SEP 7 PY 2001 VL 34 IS 35 BP 7067 EP 7079 DI 10.1088/0305-4470/34/35/331 PG 13 WC Physics, Multidisciplinary; Physics, Mathematical SC Physics GA 481VG UT WOS:000171540700032 ER PT J AU Harrison, WTA Phillips, MLF Nenoff, TM AF Harrison, WTA Phillips, MLF Nenoff, TM TI (CN3H6)(2)center dot Zn(HPO3)(2): An open-framework zincophosphite built up from polyhedral 12-rings SO JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS LA English DT Article ID PHOSPHATE; HYDROGEN; NETS AB The solution-mediated synthesis and single crystal structure of (CN3H6)(2). Zn(HPO3)(2) are reported. This phase is built up from a three-dimensional framework of vertex-linked ZnO4 and HPO3 building units encapsulating the extraframework guanidinium cations. The structure is stabilised by template-to-framework hydrogen bonding. The inorganic framework contains polyhedral 12-rings and shows a surprising similarity to those of some known organically-templated zinc phosphates. C1 Univ Aberdeen, Dept Chem, Aberdeen AB24 3UE, Scotland. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Harrison, WTA (reprint author), Univ Aberdeen, Dept Chem, Aberdeen AB24 3UE, Scotland. NR 17 TC 67 Z9 67 U1 0 U2 3 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1472-7773 J9 J CHEM SOC DALTON JI J. Chem. Soc.-Dalton Trans. PD SEP 7 PY 2001 IS 17 BP 2459 EP 2461 DI 10.1039/b102007m PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 475UF UT WOS:000171185800005 ER PT J AU Babajide, A Farber, R Hofacker, IL Inman, J Lapedes, AS Stadler, PF AF Babajide, A Farber, R Hofacker, IL Inman, J Lapedes, AS Stadler, PF TI Exploring protein sequence space using knowledge-based potentials SO JOURNAL OF THEORETICAL BIOLOGY LA English DT Article ID RNA SECONDARY STRUCTURES; NEUTRAL NETWORKS; CRYSTAL-STRUCTURE; MEAN FORCE; EXHAUSTIVE ENUMERATION; GLOBULAR-PROTEINS; MODEL PROTEINS; STRUCTURE MAPS; FOLDS; RESOLUTION AB Knowledge-based potentials can be used to decide whether an amino. acid sequence is likely to fold into a prescribed native protein structure. We use this idea to survey the sequence-structure relations in protein space. In particular, we test the following two propositions which were found to be important for efficient evolution: the sequences folding into a particular native fold form extensive neutral networks that percolate through sequence space. The neutral networks of any two native folds approach each other to within a few point mutations. Computer simulations using two very different potential functions, M. Sippl's PP,OSA pair potential and a neural network based potential, are used to verify these claims. (C) 2001 Academic Press. C1 Univ Vienna, Inst Theoret Chem & Mol Strukturbiol, A-1090 Vienna, Austria. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Santa Fe Inst, Santa Fe, NM 87501 USA. Natl Ctr Genome Resources, Santa Fe, NM 87505 USA. RP Stadler, PF (reprint author), Univ Vienna, Inst Theoret Chem, Wahringerstr 17, A-1090 Vienna, Austria. RI Hofacker, Ivo/A-2378-2013; Stadler, Peter F./L-7857-2015 OI Hofacker, Ivo/0000-0001-7132-0800; Stadler, Peter F./0000-0002-5016-5191 NR 52 TC 34 Z9 36 U1 0 U2 3 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-5193 J9 J THEOR BIOL JI J. Theor. Biol. PD SEP 7 PY 2001 VL 212 IS 1 BP 35 EP 46 DI 10.1006/jtbi.2001.2343 PG 12 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA 471FT UT WOS:000170918500003 PM 11527443 ER PT J AU Lapedes, A Farber, R AF Lapedes, A Farber, R TI The geometry of shape space: Application to influenza SO JOURNAL OF THEORETICAL BIOLOGY LA English DT Article ID HEMAGGLUTININ; PATHWAYS AB Shape space was proposed over 20 years ago as a conceptual formalism in which to represent antibody/antigen binding. It has since played a key role in computational immunology. Antigens and antibodies are considered to be points in an abstract "shape space", where coordinates of points in this space represent generalized physico-chemical properties associated with various (unspecified) physical properties related to binding, such as geometric shape, hydrophobicity, charge, etc. Distances in shape space between points representing antibodies and (the shape complement) of antigens are assumed to be related to their affinity, with small distances corresponding to high affinity. In this paper, we provide algorithms, related to metric and ordinal multidimensional scaling algorithms first developed in the mathematical psychology literature, which construct explicit, quantitative coordinates for points in shape space given experimental data such as hemagglutination inhibition assays, or other general affinity assays. Previously, such coordinates had been conceptual constructs and totally implicit. The dimension of shape space deduced from hemagglutination inhibition assays for influenza is low, approximately five dimensional. The deduction of the explicit geometry of shape space given experimental affinity data provides new ways to quantify the similarity of antibodies to antibodies, antigens to antigens, and the affinity of antigens to antibodies. This has potential utility in, e.g. strain selection decisions for annual influenza vaccines, among other applications. The analysis techniques presented here are not restricted to the analysis of antibody-antigen interactions and are generally applicable to affinity data resulting from binding assays. (C) 2001 Academic Press. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Santa Fe Inst, Santa Fe, NM 87501 USA. RP Lapedes, A (reprint author), Los Alamos Natl Lab, Div Theoret, MS B213, Los Alamos, NM 87545 USA. NR 25 TC 44 Z9 47 U1 1 U2 6 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-5193 J9 J THEOR BIOL JI J. Theor. Biol. PD SEP 7 PY 2001 VL 212 IS 1 BP 57 EP 69 DI 10.1006/jtbi.2001.2347 PG 13 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA 471FT UT WOS:000170918500005 PM 11527445 ER PT J AU Molina, PE Ahmed, N Gatley, J Volkow, ND Abumrad, NN AF Molina, PE Ahmed, N Gatley, J Volkow, ND Abumrad, NN TI L-tryptophan attenuation of the dopaminergic and behavioral responses to cocaine SO LIFE SCIENCES LA English DT Article DE cocaine; dopamine; tryptophan; microdialysis ID PROGRESSIVE RATIO SCHEDULE; NUCLEUS-ACCUMBENS; PLASMA TRYPTOPHAN; SEROTONIN; HYPERACTIVITY; REINFORCEMENT; MICRODIALYSIS; MECHANISM; DEPLETION; ACID AB This study assessed the effects of acute intravenous L-tryptophan (neutral amino acid precursor for serotonin) administration on cocaine-induced dopaminergic responses. Male Sprague-Dawley rats were surgically implanted with guide cannulas in the nucleus accumbens 5 days prior to the study and with vascular catheters (carotid artery and jugular vein) on the day prior to the study. Using microdialysis, extracellular nucleus accumbens dopamine levels were measured in freely moving rats. Following a 2 h equilibration period, animals were randomized (n=7-8 per group) to receive either a constant intravenous (IV) infusion of L-tryptophan (200 mg/kg/h) or an equal volume (2 ml/h) of saline. Ninety minutes into the infusion, cocaine (20 mg/kg) was injected intra-peritoneally. Cocaine increased nucleus accumbens microdialysate dopamine levels (500% at 30 min). This was associated with marked hyperactivity. Tryptophan infusion elevated plasma tryptophan (8-fold), and blunted the cocaine-induced increase in nucleus accumbens microdialysate dopamine levels by similar to 60%. Furthermore, tryptophan attenuated the cocaine-induced locomotor activity. These neurochemical and behavioral effects of tryptophan were associated with a marked increase in brain tissue serotonin content. The results of these studies demonstrate the feasibility of acute dietary manipulation of neurochemical and behavioral responses to cocaine. The duration, adaptation and tolerance to these effects remain to be elucidated. (C) 2001 Elsevier Science Inc. All rights reserved. C1 Louisiana State Univ, Hlth Sci Ctr, Dept Physiol, New Orleans, LA 70112 USA. Louisiana State Univ, Med Ctr, Dept Physiol, New Orleans, LA 70112 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Molina, PE (reprint author), Louisiana State Univ, Hlth Sci Ctr, Dept Physiol, 1901 Perdido St, New Orleans, LA 70112 USA. FU NIDA NIH HHS [NIDA09490-03]; NIGMS NIH HHS [NIGMS50567-07] NR 31 TC 14 Z9 14 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0024-3205 J9 LIFE SCI JI Life Sci. PD SEP 7 PY 2001 VL 69 IS 16 BP 1897 EP 1906 DI 10.1016/S0024-3205(01)01276-0 PG 10 WC Medicine, Research & Experimental; Pharmacology & Pharmacy SC Research & Experimental Medicine; Pharmacology & Pharmacy GA 473AD UT WOS:000171016400007 PM 11693270 ER PT J AU Layne, SP Beugelsdijk, TJ Patel, CKN Taubenberger, JK Cox, NJ Gust, ID Hay, AJ Tashiro, M Lavanchy, D AF Layne, SP Beugelsdijk, TJ Patel, CKN Taubenberger, JK Cox, NJ Gust, ID Hay, AJ Tashiro, M Lavanchy, D TI A global lab against influenza SO SCIENCE LA English DT Editorial Material C1 Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Los Alamos Natl Lab, Los Alamos, NM USA. Armed Forces Inst Pathol, Washington, DC 20306 USA. Ctr Dis Control & Prevent, WHO, Collaborating Ctr Influenza, Atlanta, GA USA. Victoria Univ, WHO, Collaborating Ctr Influenza, Parkville, Vic, Australia. Natl Inst Med Res, MRC, WHO, Collaborating Ctr Influenza, London NW7 1AA, England. Natl Inst Infect Dis, WHO, Collaborating Ctr Influenza, Tokyo, Japan. WHO, Influenza Program, CH-1211 Geneva, Switzerland. RP Layne, SP (reprint author), Univ Calif Los Angeles, Los Angeles, CA 90024 USA. NR 0 TC 28 Z9 29 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 7 PY 2001 VL 293 IS 5536 BP 1729 EP 1729 DI 10.1126/science.293.5536.1729 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 470WN UT WOS:000170894400003 PM 11546841 ER PT J AU Jacobs, K Zaziski, D Scher, EC Herhold, AB Alivisatos, AP AF Jacobs, K Zaziski, D Scher, EC Herhold, AB Alivisatos, AP TI Activation volumes for solid-solid transformations in nanocrystals SO SCIENCE LA English DT Article ID CDSE NANOCRYSTALS; HIGH-PRESSURE; THIN-FILM; II-VI; SIZE; METASTABILITY; SYSTEM AB The transition between four- and six-coordinate structures in CdSe nanocrystals displays simple transition kinetics as compared with the extended solid, and we determined activation volumes from the pressure dependence of the relaxation times. Our measurements indicate that the transformation takes place by a nucleation mechanism and place strong constraints on the type of microscopic motions that lead to the transformation. The type of analysis presented here is difficult for extended solids, which transform by complicated kinetics and involve ill-defined domain volumes. Solids patterned on the nanoscale may prove to be powerful models for the general study of structural transitions in small systems, as welt as in extended solids. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Alivisatos, AP (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Alivisatos , Paul /N-8863-2015 OI Alivisatos , Paul /0000-0001-6895-9048 NR 34 TC 186 Z9 188 U1 2 U2 44 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD SEP 7 PY 2001 VL 293 IS 5536 BP 1803 EP 1806 DI 10.1126/science.1063581 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 470WN UT WOS:000170894400039 PM 11546866 ER PT J AU Thompson, DW Wishart, JF Brunschwig, BS Sutin, N AF Thompson, DW Wishart, JF Brunschwig, BS Sutin, N TI Efficient generation of the ligand field excited state of tris-(2,2 '-bipyridine)-ruthenium(II) through sequential two-photon capture by [Ru(bpy)(3)](2+) or electron capture by [Ru(bpy)(3)](3+) SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Letter ID SODIUM DODECYL-SULFATE; DIMENSIONAL PROTON NMR; CHARGE-TRANSFER; FLASH-PHOTOLYSIS; POLYPYRIDINE COMPLEXES; 2-PHOTON EXCITATION; AQUEOUS-SOLUTIONS; METAL; RUTHENIUM; TRIS(2,2'-BIPYRIDINE)RUTHENIUM(II) AB The relaxation dynamics and product distribution resulting from the decay of high lying excited states generated via sequential two-photon capture by [Ru(bpy)(3)](2+) or electron capture by [Ru(bpy)(3)](3+) have been investigated by flash photolysis and pulse radiolysis techniques. In comparison to the decay dynamics for monophotonic excitation, dramatically different relaxation dynamics have been observed. High-power flash excitation yields both the lowest lying metal-to-ligand charge transfer ((MLCT)-M-3) state and a new transient photoproduct associated with nonradiative decay through the photo dissociative metal-centered ((3)dd) excited state/s. The photoproduct is postulated to be [Ru-II(bpy)(2)(eta (1)-bpy)](2+) where the pendant pyridine has rotated to yield a transient that is stabilized by pi -bonded or a three-centered Ru-C-H agostic interaction. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Rutgers State Univ, Piscataway, NJ 08854 USA. RP Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Brunschwig, Bruce/G-4249-2011; Wishart, James/L-6303-2013 OI Wishart, James/0000-0002-0488-7636 NR 50 TC 63 Z9 63 U1 0 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD SEP 6 PY 2001 VL 105 IS 35 BP 8117 EP 8122 DI 10.1021/jp011854o PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 470MW UT WOS:000170876600001 ER PT J AU Konovalova, TA Dikanov, SA Bowman, MK Kispert, LD AF Konovalova, TA Dikanov, SA Bowman, MK Kispert, LD TI Detection of anisotropic hyperfine components of chemically prepared carotenoid radical cations: 1D and 2D ESEEM and pulsed ENDOR study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELECTRON-SPIN-RESONANCE; SUBLEVEL CORRELATION SPECTROSCOPY; ECHO ENVELOPE-MODULATION; PHOTOSYSTEM-II; DISORDERED-SYSTEMS; HYSCORE; EPR; LINESHAPE; SPECTRA; SOLIDS AB Canthaxanthin and 8 ' -apo-beta -caroten-8 ' -al radical cations chemically prepared on activated silica-alumina and in CH2Cl2 solution containing AlCl3 were studied by pulsed EPR and ENDOR spectroscopies. Both the 1D three-pulse ESEEM and the 2D HYSCORE spectra of the carotenoid-AlCl3 mixtures exhibited the Al-27 nuclei peak at 3.75 MHz. This indicates electron-transfer interactions between carotenoids and Al-III ions resulting in the formation and stabilization of carotenoid radical cations. Davies ENDOR measurements of the canthaxanthin radical cation on silica-alumina determined the hyperfine couplings of protons belonging to three different methyl groups with a(H1) = 2.6 MHz, a(H2) = 8.6 MHz, and a(H3) ca. 13 MHz. The principal components of the proton hyperfine tensors were obtained from HYSCORE spectra in AlCl3 solutions and on the solid support. Identification of the protons was made on the basis of isotropic hyperfine couplings determined by RHF-INDO/SP molecular orbital calculations. In frozen AlCl3 solution, the C(7,7 ')-H alpha and C(14,14 ')-H alpha alpha protons were observed for canthaxanthin and the C(8 or 14 ')-H alpha and C(15 ')-H alpha were observed for 8 ' -apo-beta -caroten-8 ' -al. On the silica-alumina support, the C(10,10 ')-H alpha, C(11,11 ')-H alpha, and C(15,15 ')-H alpha alpha protons were measured for canthaxanthin and the C(12)-H alpha and C(15 ')-H alpha were measured for 8 ' -apo- beta -caroten-8'-al. Some protons with large isotropic couplings (> 10 MHz) determined from HYSCORE analysis could be assigned to beta protons, but the principal components of their hyperfine tensors are much more anisotropic than those reported previously for protons. We suggest that cis/trans isomerization of carotenoids on silica-alumina results in stabilization of di-cis isomers with large isotropic couplings for some alpha protons which are comparable to those of beta protons. HYSCORE is a promising technique to increase spectral resolution for proper assignment of protons with large hyperfine anisotropy, which cannot be resolved by ENDOR spectroscopy. C1 Univ Alabama, Dept Chem, Tuscaloosa, AL 35487 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Illinois, Illinois EPR Res Ctr, Urbana, IL 61801 USA. Univ Illinois, Dept Vet Clin Med, Urbana, IL 61801 USA. Inst Chem Kinet & Combust, Novosibirsk 630090, Russia. RP Kispert, LD (reprint author), Univ Alabama, Dept Chem, Box 870336, Tuscaloosa, AL 35487 USA. RI Bowman, Michael/F-4265-2011 OI Bowman, Michael/0000-0003-3464-9409 NR 29 TC 13 Z9 14 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 6 PY 2001 VL 105 IS 35 BP 8361 EP 8368 DI 10.1021/jp010960n PG 8 WC Chemistry, Physical SC Chemistry GA 470MQ UT WOS:000170876100016 ER PT J AU Koper, MTM Schmidt, TJ Markovic, NM Ross, PN AF Koper, MTM Schmidt, TJ Markovic, NM Ross, PN TI Potential oscillations and S-shaped polarization curve in the continuous electro-oxidation of CO on platinum single-crystal electrodes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELECTROCHEMICAL SYSTEMS; CARBON-MONOXIDE; H-2/CO MIXTURES; ACID-SOLUTIONS; PT-RU; ELECTROOXIDATION; PT(100); PT(111); MODEL; DISK AB The occurrence of an S-shaped polarization curve in a simple model for the continuous electrochemical oxidation of CO on a platinum electrode is discussed. In the model, the S-shaped polarization curve is caused by the competitive Langmuir-Hinshelwood mechanism between surface-bonded CO and OH. The reaction is studied experimentally on single-crystal platinum rotating disk electrodes in perchloric and sulfuric acid solution, and it is shown that the voltammetry is in good agreement with the model predictions. When studied under current-controlled conditions, a fast galvanodynamic scan indeed suggests the existence of the S-shaped polarization curve. At lower scan rates, however, irregularities and small-amplitude irregular fluctuations or oscillations in potential are observed. Very regular potential oscillations under current-controlled conditions are observed only on Pt(111) in sulfuric acid. The possible origin of these irregularities and oscillations is discussed in relation to the existing theories of electrochemical instabilities. C1 Eindhoven Univ Technol, Schuit Inst Catalysis, Inorgan Chem & Catalysis Lab, NL-5600 MB Eindhoven, Netherlands. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Koper, MTM (reprint author), Eindhoven Univ Technol, Schuit Inst Catalysis, Inorgan Chem & Catalysis Lab, NL-5600 MB Eindhoven, Netherlands. RI Schmidt, Thomas/A-2586-2010; Koper, Marc/C-5026-2009 OI Schmidt, Thomas/0000-0002-1636-367X; NR 25 TC 59 Z9 60 U1 1 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 6 PY 2001 VL 105 IS 35 BP 8381 EP 8386 DI 10.1021/jp011410s PG 6 WC Chemistry, Physical SC Chemistry GA 470MQ UT WOS:000170876100019 ER PT J AU Levitsky, IA Krivoshlykov, SG Grate, JW AF Levitsky, IA Krivoshlykov, SG Grate, JW TI Signal amplification in multichromophore luminescence-based sensors SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ENERGY-TRANSFER; ACOUSTIC-WAVE; FLUORESCENCE; POLYMERS; SENSITIVITY; ARRAYS AB A method for signal amplification in the detection of vapors with luminescence-based sensors is described. Amplification involves energy transfer between two or more fluorescent chromophores in a carefully selected polymer matrix. A quantitative model has been derived that can be applied to any luminescence sensor comprising donor-acceptor pairs, and it can be generalized to multichromophore systems with n chromophores leading to n-fold signal amplification. Signal amplification has been demonstrated experimentally in the fluorescent sensing of dimethyl methylphosphonate (DMMP) using two dyes, 3-aminofluoranten (AM) and Nile Red (NR), in a hydrogen-bond acidic polymer matrix. The selected polymer matrix quenches the fluorescence of both dyes and shifts dye emission and absorption spectra relative to those of more inert matrixes. Upon DMMP sorption, the AM fluorescence shifts to the red at the same time that the NR absorption shifts to the blue, resulting in more band overlap and increased energy transfer between chromophores. In addition, the emission of both chromophores is enhanced. Using an excitation wavelength tuned to the AM dye, we found that the absolute signal magnitude observed upon DMMP exposure in the two-dye film was an order of magnitude greater than that observed when using a single-dye NR-containing film. The ratio of the response signal under vapor exposure to the signal prior to exposure was 250 for the two-dye film compared to 15 for single-dye, films. The two-dye approach to signal amplification also significantly increases the selectivity relative to the potentially interfering vapors. Experimental results to date favor a reabsorption mechanism over a Forster radiationless direct energy-transfer mechanism. C1 LLC, ALTAIR Ctr, Shrewsbury, MA 01545 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Levitsky, IA (reprint author), LLC, ALTAIR Ctr, 1 Chartwell Circle, Shrewsbury, MA 01545 USA. NR 32 TC 17 Z9 17 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD SEP 6 PY 2001 VL 105 IS 35 BP 8468 EP 8473 DI 10.1021/jp011376h PG 6 WC Chemistry, Physical SC Chemistry GA 470MQ UT WOS:000170876100032 ER PT J AU Gramer, CJ Raymond, KN AF Gramer, CJ Raymond, KN TI A streamlined synthesis for 2,3-dihydroxyterephthalamides SO ORGANIC LETTERS LA English DT Article ID SEQUESTERING AGENTS; (+)-OBAFLUORIN; ENTEROBACTIN AB [GRAPHICS] 2,3-Dihydroxyterephthalamides have been synthesized through a route that avoids the protection and deprotection of the phenol groups. The procedure allows for symmetric and unsymmetric amide linkages. This synthetic sequence significantly decreases the time and cost of preparation and increases the overall yield of this class of metal chelators. C1 Univ Calif Berkeley, Div Chem Sci, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Raymond, KN (reprint author), Univ Calif Berkeley, Div Chem Sci, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 25 TC 15 Z9 16 U1 2 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1523-7060 J9 ORG LETT JI Org. Lett. PD SEP 6 PY 2001 VL 3 IS 18 BP 2827 EP 2830 DI 10.1021/ol016253u PG 4 WC Chemistry, Organic SC Chemistry GA 469MX UT WOS:000170820400011 PM 11529767 ER PT J AU Atwood, D Soni, A AF Atwood, D Soni, A TI Determining the phases alpha and gamma from time-dependent CP violation in B-0 decays to rho(omega) plus pseudoscalar SO PHYSICS LETTERS B LA English DT Article ID B-MESON DECAYS; EXTRACTION; ETA' AB A method is proposed for the determination of the unitarity angle a through tree penguin interference. The modes needed would be of the form B-0/(B) over bar (0) --> rho M-0 and B-0/(B) over bar (0) --> omegaM where M is spin-0 u (u) over bar /d (d) over bar meson, for instance M = pi (0), eta, eta', a(0) or f(0). An analogous method can also determine gamma using M = K-S or K-L. The validity of the theoretical approximations used may be tested by over determining alpha with several modes. If two or more modes are used, the determination has a four-fold ambiguity but additional information from pure penguin decays or theoretical estimates may be used to reduce the ambiguity to alpha, alpha + 7 pi. The method as applied to determining gamma is probably less promising. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Brookhaven Natl Lab, Theory Grp, Upton, NY 11973 USA. RP Atwood, D (reprint author), Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. NR 37 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD SEP 6 PY 2001 VL 516 IS 1-2 BP 39 EP 46 DI 10.1016/S0370-2693(01)00900-5 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 469ZM UT WOS:000170846000005 ER PT J AU Bodeker, D AF Bodeker, D TI A local Langevin equation for slow long-distance modes of hot non-Abelian gauge fields SO PHYSICS LETTERS B LA English DT Article ID HARD THERMAL LOOPS; SIMONS NUMBER DIFFUSION; HIGH-TEMPERATURE; SPHALERON RATE; QCD; DYNAMICS; PLASMA; ENERGY AB The effective theory for the dynamics of hot non-Abelian gauge fields with spatial momenta of order of the magnetic screening scale g(2)T is described by a Boltzmann equation. The dynamical content of this theory is explored. There are three relevant frequency scales, gT, g(2)T and g(4)T, associated with plasmon oscillations, multipole fluctuations of the charged particle distribution, and with the nonperturbative gauge field dynamics, respectively. The frequency scale gT is integrated out. The result is a local Langevin-type equation. It is valid to leading order in g and to all orders in log(1/g), and it does not suffer from the hard thermal loop divergences of classical thermal Yang-Mills theory. We then derive the corresponding Fokker-Planck equation, which is shown to generate an equilibrium distribution corresponding to 3-dimensional Yang-Mills theory plus a Gaussian free field. (C) 2001 Published by Elsevier Science B.V. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RIKEN, BNL, Res Ctr, Upton, NY 11973 USA. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM bodeker@bnl.gov NR 32 TC 12 Z9 12 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD SEP 6 PY 2001 VL 516 IS 1-2 BP 175 EP 182 DI 10.1016/S0370-2693(01)00911-X PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 469ZM UT WOS:000170846000025 ER PT J AU Ogunsola, OI Shadle, LJ Casleton, K Mei, J AF Ogunsola, OI Shadle, LJ Casleton, K Mei, J TI Investigation of the causes of seasonal variations in NOx emissions from waste-coal-fired circulating fluidized-bed utility plants SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID NITROUS-OXIDE; FUEL PROPERTIES; COMBUSTION; CONVERSION; LIMESTONE AB The results of a study aimed at identifying and understanding possible causes of seasonal variations in NOx, emissions from circulating fluidized-bed (CFB) coal-fired power plants are. discussed. Historical data on fuel properties, operating conditions, and emission characteristics provided by two plants were used. The extensive data were carefully and thoroughly examined and analyzed for any evidence of seasonal variations in NOx and any of the variables and relationships between NOx and the pertinent parameters. Prior to the comprehensive data analyses, a review of the literature was conducted to identify the NOx dependence parameters or variables of importance. Results obtained reveal that relatively higher ammonia was required to control NOx in the winter compared to the rest of the year at the plant that uses this compound to control NOx. NOx emission and a number of operating conditions/factors (bed temperature, excess oxygen, cyclone outlet temperature, and Ca/S ratio) were observed to vary unpredictably with season, whereas a predictable seasonal variation was observed for a few other factors (humidity ratio, ammonia consumption, fuel moisture content, and ambient air temperature). Bed temperature, excess oxygen, cyclone outlet temperature, Ca/S ratio, and ammonia consumption were suspected to be related to the variations in NOx emission. C1 US DOE, Natl Energy Technol Ctr, Morgantown, WV 26507 USA. RP Shadle, LJ (reprint author), US DOE, Natl Energy Technol Ctr, 3610 Collins Ferry Rd, Morgantown, WV 26507 USA. OI Shadle, Lawrence/0000-0002-6283-3628 NR 53 TC 2 Z9 2 U1 2 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD SEP 5 PY 2001 VL 40 IS 18 BP 3869 EP 3878 DI 10.1021/ie001114m PG 10 WC Engineering, Chemical SC Engineering GA 468EE UT WOS:000170744500003 ER PT J AU Gomez-Vega, JM Hozumi, A Saiz, E Tomsia, AP Sugimura, H Takai, O AF Gomez-Vega, JM Hozumi, A Saiz, E Tomsia, AP Sugimura, H Takai, O TI Bioactive glass-mesoporous silica coatings on Ti6Al4V through enameling and triblock-copolymer-templated sol-gel processing SO JOURNAL OF BIOMEDICAL MATERIALS RESEARCH LA English DT Article DE glass coating; mesoporous silica; triblock copolymer; apatite; bioactivity ID TITANIUM IMPLANT ALLOYS; TI-BASED IMPLANTS; BLOCK-COPOLYMERS; PREPARED SILICA; THIN-FILMS; HYDROXYAPATITE; PHOSPHATE; BIOGLASS(R); INDUCTION; PATHWAYS AB The combination of thick glass coatings that can protect Ti6Al4V from corrosion in the body fluids, and mesoporous silica films able to readily induce the formation of apatite when immersed in a simulated body fluid (SBF), has been investigated in this work as a possible route towards more resistant and long-lasting implants. Glasses in the system Si-Ca-Mg-Na-K-P-O with thermal expansion coefficients close to that of Ti6Al4V were prepared and used to coat this alloy by an enameling technique. However, the glasses apt to coat Ti6A14V exhibited a very limited capacity to induce apatite formation in SBF. In order to enhance their bioactivity, a thin film of mesoporous silica was applied on the exterior of the specimens by spin coating a sol-gel solution. When tested in SBF, these coatings induced apatite formation after 7 days. The mesoporosity of the silica film was created through a triblock-copolymer-templating process. The diameters of the mesochannels could be adjusted by changing the size of the directing agent. A preferred alignment of the mesostructure was observed. The removal of the organic templates could be achieved through a photocalcination treatment, which, compared to conventional thermocalcination, offered several advantages. (C) 2001 John Wiley & Sons, Inc. C1 Nagoya Univ, Grad Sch Engn, Dept Mat Proc Engn, Chikusa Ku, Nagoya, Aichi 4648603, Japan. Natl Ind Res Inst Nagoya, Kita Ku, Nagoya, Aichi 4628510, Japan. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Gomez-Vega, JM (reprint author), Nagoya Univ, Grad Sch Engn, Dept Mat Proc Engn, Chikusa Ku, Furo Cho, Nagoya, Aichi 4648603, Japan. EM jose@plasma.numse.nagoya-u.ac.jp FU NIDCR NIH HHS [1R01 DE11289] NR 39 TC 38 Z9 39 U1 2 U2 23 PU JOHN WILEY & SONS INC PI HOBOKEN PA 111 RIVER ST, HOBOKEN, NJ 07030 USA SN 0021-9304 J9 J BIOMED MATER RES JI J. Biomed. Mater. Res. PD SEP 5 PY 2001 VL 56 IS 3 BP 382 EP 389 DI 10.1002/1097-4636(20010905)56:3<382::AID-JBM1107>3.0.CO;2-P PG 8 WC Engineering, Biomedical; Materials Science, Biomaterials SC Engineering; Materials Science GA 442DV UT WOS:000169270700009 PM 11372056 ER PT J AU Rubin, SM Spence, MM Dimitrov, IE Ruiz, EJ Pines, A Wemmer, DE AF Rubin, SM Spence, MM Dimitrov, IE Ruiz, EJ Pines, A Wemmer, DE TI Detection of a conformational change in maltose binding protein by Xe-129 NMR spectroscopy SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID LASER-POLARIZED XENON; ACTIVE-TRANSPORT; LIGAND-BINDING; CHEMOTAXIS; CAVITIES; RESONANCE; MYOGLOBIN; BLOOD C1 Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Penn, Dept Radiol, MMRRCC, Philadelphia, PA 19104 USA. RP Wemmer, DE (reprint author), Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. OI Dimitrov, Ivan/0000-0003-2686-6884 FU NCRR NIH HHS [RR02305] NR 28 TC 35 Z9 36 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD SEP 5 PY 2001 VL 123 IS 35 BP 8616 EP 8617 DI 10.1021/ja0110325 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 467XN UT WOS:000170729200029 PM 11525678 ER PT J AU Stratton, JR Pelton, JG Kirsch, JF AF Stratton, JR Pelton, JG Kirsch, JF TI A novel engineered subtilisin BPN ' lacking a low-barrier hydrogen bond in the catalytic triad SO BIOCHEMISTRY LA English DT Article ID ENZYMATIC CATALYSIS; FRACTIONATION FACTORS; CITRATE SYNTHASE; TRIOSEPHOSPHATE ISOMERASE; ACTIVATION-ENERGIES; INHIBITOR COMPLEX; SERINE PROTEASES; CHYMOTRYPSIN; PROTON; STABILIZATION AB The low-barrier hydrogen bond (LBHB) between the Asp and His residues of the catalytic triad in a serine protease was perturbed via the D32C mutation in subtilisin BPN ' (Bacillus protease N '). This mutant enzyme catalyzes the hydrolysis of N-Suc-Ala-Ala-Pro-Phe-SBzl with a k(cat)/K-m value that is only 8-fold reduced from that of the wild-type (WT) enzyme. The value of k(cat)/K-m for the corresponding p-nitroanilide (pNA) substrate is only 50-fold lower than that of the WT enzyme (Delta DeltaG(double dagger) = 2.2 kcal/mol). The pK(a) controlling the ascending limb of the pH versus k(cat)/K-m profile is lowered from 7.01 (WT) to 6.53 (D32C), implying that any hydrogen bond replacing that between Asp32 and His64 of the WT enzyme most likely involves the neutral thiol rather than the thiolate form of Cys32. It is shown by viscosity variation that the reaction of WT subtilisin with N-Suc-Ala-Ala-Pro-Phe-SBzl is 50% (sucrose) to 100% (glycerol) diffusion-con trolled, while that of the D32C construct is 29% (sucrose) to 76% (glycerol) diffusion-controlled. The low-field NMR resonance of 18 ppm that has been assigned to a proton shared by Asp32 and His64, and is considered diagnostic of a LBHB in the WT enzyme, is not present in D32C subtilisin. Thus, the LBHB is not an inherent requirement for substantial rate enhancement for subtilisin. C1 Univ Calif Berkeley, Dept Mol & Cellular Biol, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Phys Biosci Div, Berkeley, CA 94710 USA. RP Kirsch, JF (reprint author), Univ Calif Berkeley, Dept Mol & Cellular Biol, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM35393] NR 53 TC 22 Z9 22 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD SEP 4 PY 2001 VL 40 IS 35 BP 10411 EP 10416 DI 10.1021/bi015542n PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 467YT UT WOS:000170731900001 PM 11523982 ER PT J AU Campbell, ML Apodaca, DL Yates, MZ McCleskey, TM Birnbaum, ER AF Campbell, ML Apodaca, DL Yates, MZ McCleskey, TM Birnbaum, ER TI Metal extraction from heterogeneous surfaces using carbon dioxide microemulsions SO LANGMUIR LA English DT Article ID SUPERCRITICAL-FLUID EXTRACTION; CHELATING-AGENTS; AQUEOUS-SOLUTIONS; SOLID MATERIALS; WATER; SOLUBILITIES; ENVIRONMENT; SURFACTANTS AB We have demonstrated that water in carbon dioxide (w/c) microemulsions extract copper and europium ions from a variety of solid substrates in high yields. The microemulsions are unique from bulk aqueous extractions in that the volume of water used is similar to that of the metal extracted, rather than that of the entire solid substrate, allowing grams of waste to be extracted with microliters of water. The microemulsion enhances wetting without saturation of the solid matrix, allowing almost complete recovery of the metal ions. Our results show that > 98% of the metal can be recovered from a filter paper surface in a single extrtaction step. Extraction experiments using wood spiked with metal ions have shown that the microemulsions have enhanced diffusivity compared to bulk water. Pressure changes allow recovery and regeneration of the surfactant; in a test case, 81% of the initial capacity is achieved upon reexposure of the w/c microemulsion to a second batch of copper nitrate. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Birnbaum, ER (reprint author), Los Alamos Natl Lab, Div Chem, MS E518, Los Alamos, NM 87545 USA. RI McCleskey, Thomas/J-4772-2012; OI Mccleskey, Thomas/0000-0003-3750-3245 NR 24 TC 31 Z9 31 U1 1 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD SEP 4 PY 2001 VL 17 IS 18 BP 5458 EP 5463 DI 10.1021/la0104166 PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 468FE UT WOS:000170746800009 ER PT J AU Nieh, TG Wadsworth, J Liu, CT Ohkubo, T Hirotsu, Y AF Nieh, TG Wadsworth, J Liu, CT Ohkubo, T Hirotsu, Y TI Plasticity and structural instability in a bulk metallic glass deformed in the supercooled liquid region SO ACTA MATERIALIA LA English DT Article DE metallic glasses; superplasticity; amorphous materials ID AMORPHOUS-ALLOYS; NEWTONIAN FLOW; DEFORMATION; BEHAVIOR; CRYSTALLIZATION; SUPERPLASTICITY; STRENGTH; PHASE AB The deformation behavior of a bulk amorphous Zr-10Al-5Ti-17.9Cu-14.6Ni alloy was characterized in the supercooled liquid re.-ion, The alloy was observed to exhibit Newtonian behavior at low strain rates but to become non-Newtonian at high strain rates. Structures of the amorphous material, both before and after deformation, were examined using X-ray diffraction and high-resolution electron microscopy. Experimental results showed the presence of nanocrystallites in the deformed samples, suggesting that the non-Newtonian behavior,vas associated with the concurrent crystallization of the amorphous structure during deformation; that is, a mixed crystalline-plus-amorphous structure was being tested. A mechanistic model based upon structural evolution has been developed to interpret the observed non-Newtonian behavior. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Osaka Univ, Inst Sci & Ind Res, Osaka 5670047, Japan. RP Nieh, TG (reprint author), Lawrence Livermore Natl Lab, POB 808,L-350, Livermore, CA 94551 USA. RI Nieh, Tai-Gang/G-5912-2011; OI Nieh, Tai-Gang/0000-0002-2814-3746; Liu, Chain Tsuan/0000-0001-7888-9725 NR 32 TC 170 Z9 191 U1 0 U2 24 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD SEP 3 PY 2001 VL 49 IS 15 BP 2887 EP 2896 DI 10.1016/S1359-6454(01)00218-X PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 466NR UT WOS:000170652100003 ER PT J AU Holm, EA Hassold, GN Miodownik, MA AF Holm, EA Hassold, GN Miodownik, MA TI On misorientation distribution evolution during anisotropic grain growth SO ACTA MATERIALIA LA English DT Article DE grain growth; computer simulation; grain boundaries; microstructure; texture ID MONTE-CARLO-SIMULATION; MICROSTRUCTURAL EVOLUTION; COMPUTER-SIMULATION; BOUNDARY ENERGIES; POTTS-MODEL; ORIENTATION; MOBILITIES; KINETICS AB In order to study the development of texture and boundary character during annealing, three-dimensional grain crystallography and crystallographically mediated grain boundary properties were incoporated into a finite temperature Monte Carlo model for.-rain growth. Randomly textured microstructures evolve normally, with growth exponent n = 0.96. While texture remains random, the steady-state boundary misorientation distribution favors low-angle boundaries. To first order, low-angle boundaries increase by lengthening, not by proliferating. In contrast, microstructures with a strong single-component texture develop four-grain junctions and highly curved grain boundaries, which alter evolution. The boundary misorientation distribution narrows and shifts to low angles, and no steady state is observed. The accompanying decrease in mean boundary mobility causes growth to slow, resulting in a growth exponent n = 0.62. The dependence of the growth exponent on average boundary mobility may explain experimental observations of exponents less than unity. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Kettering Univ, Dept Sci & Math, Flint, MI 48504 USA. Kings Coll London, Dept Mech Engn, London, England. RP Holm, EA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM eaholm@sandia.gov RI Holm, Elizabeth/S-2612-2016 OI Holm, Elizabeth/0000-0003-3064-5769 NR 37 TC 130 Z9 133 U1 2 U2 26 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD SEP 3 PY 2001 VL 49 IS 15 BP 2981 EP 2991 DI 10.1016/S1359-6454(01)00207-5 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 466NR UT WOS:000170652100012 ER PT J AU Tome, CN Maudlin, PJ Lebensohn, RA Kaschner, GC AF Tome, CN Maudlin, PJ Lebensohn, RA Kaschner, GC TI Mechanical response of zirconium - I. Derivation of a polycrystal constitutive law and finite element analysis SO ACTA MATERIALIA LA English DT Article DE texture; polycrystal modeling ID SELF-CONSISTENT APPROACH; TEXTURE DEVELOPMENT; CRYSTALLOGRAPHIC TEXTURE; DEFORMATION; MODEL; PLASTICITY; PREDICTION; BEHAVIOR; ALLOYS AB Stimulating the forming of anisotropic polycrystals, such as zirconium, requires a description of the anisotropy of the aggregate and the single crystal, and also of their evolution with deformation (texture development and hardening). Introducing the anisotropy of the single crystal requires the use of polycrystal models that account for inhomogeneous deformation depending on grain orientation. In particular, visco-plastic self-consistent models have been successfully used for describing strongly anisotropic aggregates. As a consequence, using a polycrystal. constitutive law inside finite element (FE) codes represents a considerable improvement over using empirical constitutive laws, since the former provides a physically based description of anisotropy and its evolution. In this work we develop a polycrystal constitutive description for pure Zr deforming under quasi-static conditions at room and liquid nitrogen temperatures, We use tensile and compressive experimental data obtained from a clock-rolled Zr sheet to adjust the constitutive parameters of the polycrystal model. Twinning is accounted for in the description. The polycrystal model is implemented into an explicit FE code, assuming a full polycrystal at the position of each integration point. The orientation and hardening of the individual grains associated with each element is updated as deformation proceeds. We report preliminary results of this methodology applied to simulate the three-dimensional deformation of zirconium bars deforming under four-point bend conditions to maximum strains of about 20%. A critical comparison between experiments and predictions is done in a second paper Published by Elsevier Science Ltd on behalf of Acta Materialia Inc. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Inst Fis Rosario, RA-2000 Rosario, Argentina. RP Los Alamos Natl Lab, MST-8 MS G755, Los Alamos, NM 87545 USA. EM tome@lanl.gov RI Lebensohn, Ricardo/A-2494-2008; Tome, Carlos/D-5058-2013; Kaschner, George/H-4445-2013 OI Lebensohn, Ricardo/0000-0002-3152-9105; NR 27 TC 157 Z9 157 U1 3 U2 36 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD SEP 3 PY 2001 VL 49 IS 15 BP 3085 EP 3096 DI 10.1016/S1359-6454(01)00190-2 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 466NR UT WOS:000170652100022 ER PT J AU Kaschner, GC Bingert, JF Liu, C Lovato, ML Maudlin, PJ Stout, MG Tome, CN AF Kaschner, GC Bingert, JF Liu, C Lovato, ML Maudlin, PJ Stout, MG Tome, CN TI Mechanical response of zirconium - II. Experimental and finite element analysis of bent beams SO ACTA MATERIALIA LA English DT Article DE texture; bent beam AB In a companion paper [Acta mater. 2001, 49(15), 3085-3096] we develop a polycrystal constitutive law that incorporates the deformation mechanisms operating in high purity zirconium (Zr) at liquid nitrogen (LN) and room temperature (RT). In this paper we present results of 4-point bending tests performed on beams of highly textured zirconium. These tests have been performed at LN and RT, in two orthogonal bending planes, and up to a strain of approximately 20% in the outermost fibers of the beams. A novel experimental technique, dot-matrix deposition and mapping (DMDM), has been developed and employed to analyze the distribution of local plastic strain and macroscopic deformation in the deformed beams, Automated electron backscatter diffraction (EBSD) pattern analysis has been used to evaluate the textures just below the outermost tensile and compressive surfaces and at the neutral plane. Experimental results compare very well with the predictions of finite element (FE) simulations obtained using the constitutive law developed in Part I. Specifically, we compare local deformation, macroscopic deformation and local texture in the beam. We show that the contribution of twinning to deformation results in different qualitative responses in the compressive and tensile fibers of the bent beam. Our results indicate the necessity of using a constitutive description that accounts for the anisotropy of the aggregate and for its evolution with deformation. Published by Elsevier Science Ltd on behalf of Acta Materialia Inc. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Tome, CN (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Tome, Carlos/D-5058-2013; Kaschner, George/H-4445-2013 NR 8 TC 46 Z9 47 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD SEP 3 PY 2001 VL 49 IS 15 BP 3097 EP 3108 DI 10.1016/S1359-6454(01)00191-4 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 466NR UT WOS:000170652100023 ER PT J AU De Arellano-Lopez, AR Balachandran, U Goretta, KC Ma, B Routbort, JL AF De Arellano-Lopez, AR Balachandran, U Goretta, KC Ma, B Routbort, JL TI High-temperature deformation of Sr(FeCo)(1.5)O-X ceramics SO ACTA MATERIALIA LA English DT Article DE creep; microstructure; functional ceramics; non-binary; crystalline oxides ID RETROGRADE DENSIFICATION; OXYGEN PERMEATION; CREEP; SUPERCONDUCTORS; DIFFUSION; MEMBRANES; SRCO0.8FE0.2O3-DELTA; SRFECO0.5OX; CONDUCTORS; FLOW AB Compressive creep of polycrystalline SrFe1.2Co0.30Ox and SrFeCo0.50Ox ceramics has been investigated at 940-1000 degreesC in constant-load and constant-displacement-rate experiments. At low stresses, the stress exponent was approximate to1 and the activation energy was approximate to 110-135 kJ/mol. At higher stresses, a transition occurred and the stress exponent became approximate to2.4-3.1 and the activation energy became approximate to 425-453 kJ/mol. At higher stresses, there was no dependence of the steady-state flow stress on oxygen partial pressure from 10-10(5) Pa. The creep parameters and scanning and transmission electron microscopy observations of the deformed samples suggested that deformation was controlled by diffusion at low stresses and dislocation glide at high stresses. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Sevilla, Dept Fis Mat Condensada, E-41080 Seville, Spain. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP De Arellano-Lopez, AR (reprint author), Univ Sevilla, Dept Fis Mat Condensada, POB 1065, E-41080 Seville, Spain. RI Ma, Beihai/I-1674-2013; OI Ma, Beihai/0000-0003-3557-2773; R. de Arellano Lopez, Antonio/0000-0002-7443-0244 NR 43 TC 9 Z9 9 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD SEP 3 PY 2001 VL 49 IS 15 BP 3109 EP 3116 DI 10.1016/S1359-6454(01)00164-1 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 466NR UT WOS:000170652100024 ER PT J AU Venezia, VC Kalyanaraman, R Gossmann, HJL Rafferty, CS Werner, P AF Venezia, VC Kalyanaraman, R Gossmann, HJL Rafferty, CS Werner, P TI Depth dependence of {311} defect dissolution SO APPLIED PHYSICS LETTERS LA English DT Article ID TRANSIENT ENHANCED DIFFUSION; ION-IMPLANTATION; SI; SILICON; INTERSTITIALS; SURFACE AB A deep band of {311} defects was created 520 nm below the silicon surface with a 350 keV Si implant followed by a cluster-forming rapid thermal anneal (800 degreesC, 1000 s). Chemical etching was used to vary the depth to the surface of the {311}-defect band. Afterwards, the defect dissolution was investigated at 750 degreesC for different times. Varying the depth in this fashion assures that only the depth and no other feature of the cluster distribution is changed. The {311} defects were analyzed by plan-view, transmission electron microscopy. We show that the dissolution time of the {311}-defect band varies linearly with depth, confirming that surface recombination controls the dissolution and is consistent with analogous observations of transient enhanced diffusion. (C) 2001 American Institute of Physics. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Max Planck Inst Microstruct Phys, D-06120 Halle Saale, Germany. RP Venezia, VC (reprint author), Philips Res Leuven, Kapledreef 75, B-3001 Louvain, Belgium. NR 14 TC 21 Z9 21 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 3 PY 2001 VL 79 IS 10 BP 1429 EP 1431 DI 10.1063/1.1392972 PG 3 WC Physics, Applied SC Physics GA 466LN UT WOS:000170647200007 ER PT J AU Bhattacharyya, S Auciello, O Birrell, J Carlisle, JA Curtiss, LA Goyette, AN Gruen, DM Krauss, AR Schlueter, J Sumant, A Zapol, P AF Bhattacharyya, S Auciello, O Birrell, J Carlisle, JA Curtiss, LA Goyette, AN Gruen, DM Krauss, AR Schlueter, J Sumant, A Zapol, P TI Synthesis and characterization of highly-conducting nitrogen-doped ultrananocrystalline diamond films SO APPLIED PHYSICS LETTERS LA English DT Article ID N-TYPE DIAMOND; NANOCRYSTALLINE DIAMOND; GRAIN-BOUNDARIES; THIN-FILMS; CVD DIAMOND; GROWTH; PLASMAS; CARBON; ENERGY; DOPANT AB Ultrananocrystalline diamond (UNCD) films with up to 0.2% total nitrogen content were synthesized by a microwave plasma-enhanced chemical-vapor-deposition method using a CH4(1%)/Ar gas mixture and 1%-20% nitrogen gas added. The electrical conductivity of the nitrogen-doped UNCD films increases by five orders of magnitude (up to 143 Ohm (-1) cm(-1)) with increasing nitrogen content. Conductivity and Hall measurements made as a function of film temperature down to 4.2 K indicate that these films have the highest n-type conductivity and carrier concentration demonstrated for phase-pure diamond thin films. Grain-boundary conduction is proposed to explain the remarkable transport properties of these films. (C) 2001 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Carlisle, JA (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Zapol, Peter/G-1810-2012; Bhattacharyya, Somnath/M-1867-2015 OI Zapol, Peter/0000-0003-0570-9169; Bhattacharyya, Somnath/0000-0002-6435-7864 NR 31 TC 320 Z9 324 U1 9 U2 94 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD SEP 3 PY 2001 VL 79 IS 10 BP 1441 EP 1443 DI 10.1063/1.1400761 PG 3 WC Physics, Applied SC Physics GA 466LN UT WOS:000170647200011 ER PT J AU Soininen, JA Hamalainen, K Caliebe, WA Kao, CC Shirley, EL AF Soininen, JA Hamalainen, K Caliebe, WA Kao, CC Shirley, EL TI Core-hole-electron interaction in x-ray Raman scattering SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID AB-INITIO CALCULATION; DYNAMIC STRUCTURE FACTOR; ENERGY-LOSS SCATTERING; EXCHANGE-CORRELATION; DIELECTRIC MATRICES; OPTICAL-ABSORPTION; DIAMOND; SEMICONDUCTORS; EXCITON; INSULATORS AB This work applies a recently developed first-principles scheme for calculating core excited states in solids to non-resonant inelastic x-ray scattering. The model explicitly includes the interaction between the excited electron and the core hole. The calculated results are compared with recent experimental results on inelastic x-ray scattering from K shells of Li, Be and C in lithium fluoride, beryllium oxide and diamond, respectively. The overall agreement between experimental and theoretical spectra is found to be good in all cases, even for the near-edge structure. C1 Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. Natl Inst Stand & Technol, Phys Lab, Opt Technol Div, Gaithersburg, MD 20899 USA. RP Univ Helsinki, Dept Phys, POB 64, FIN-00014 Helsinki, Finland. RI Hamalainen, Keijo/A-3986-2010 OI Hamalainen, Keijo/0000-0002-9234-9810 NR 41 TC 35 Z9 35 U1 1 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 EI 1361-648X J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD SEP 3 PY 2001 VL 13 IS 35 BP 8039 EP 8047 DI 10.1088/0953-8984/13/35/311 PG 9 WC Physics, Condensed Matter SC Physics GA 479QV UT WOS:000171415800016 ER PT J AU Ini, S Oliver, AG Tilley, TD Bergman, RG AF Ini, S Oliver, AG Tilley, TD Bergman, RG TI Synthesis, structure, and hydrosilylation catalysis of a chiral A-frame rhodium(I) dimer with cis diphosphite ligands SO ORGANOMETALLICS LA English DT Article ID COMPLEXES; COOPERATIVITY AB This paper reports the synthesis and structure of two new dinuclear chiral rhodium(I) complexes which feature a "cis-A-frame" geometry and their use as catalysts for the hydrosilylation of aromatic ketones. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Tilley, TD (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 20 TC 20 Z9 20 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD SEP 3 PY 2001 VL 20 IS 18 BP 3839 EP 3841 DI 10.1021/om010428m PG 3 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 470UW UT WOS:000170890400003 ER PT J AU Back, BB Baker, MD Barton, DS Betts, RR Bindel, R Budzanowski, A Busza, W Carroll, A Decowski, MP Garcia, E George, N Gulbrandsen, K Gushue, S Halliwell, C Heintzelman, GA Henderson, C Hofman, DJ Holynski, R Holzman, B Johnson, E Kane, JL Katzy, J Khan, N Kucewicz, W Kulinich, P Lin, WT McLeod, D Michalowski, J Mignerey, AC Mulmenstadt, J Nouicer, R Olszewski, A Pak, R Park, IC Pernegger, H Reed, C Remsberg, LP Reuter, M Roland, C Roland, G Rosenberg, L Sarin, P Sawicki, P Skulski, W Steadman, SG Steinberg, P Stephans, GSF Stodulski, M Sukhanov, A Tang, JL Teng, R Trzupek, A Vale, C van Nieuwenhuizen, GJ Verdier, R Wadsworth, B Wolfs, FLH Woseik, B Wozniak, K Wuosmaa, AH Wyslouch, B AF Back, BB Baker, MD Barton, DS Betts, RR Bindel, R Budzanowski, A Busza, W Carroll, A Decowski, MP Garcia, E George, N Gulbrandsen, K Gushue, S Halliwell, C Heintzelman, GA Henderson, C Hofman, DJ Holynski, R Holzman, B Johnson, E Kane, JL Katzy, J Khan, N Kucewicz, W Kulinich, P Lin, WT McLeod, D Michalowski, J Mignerey, AC Mulmenstadt, J Nouicer, R Olszewski, A Pak, R Park, IC Pernegger, H Reed, C Remsberg, LP Reuter, M Roland, C Roland, G Rosenberg, L Sarin, P Sawicki, P Skulski, W Steadman, SG Steinberg, P Stephans, GSF Stodulski, M Sukhanov, A Tang, JL Teng, R Trzupek, A Vale, C van Nieuwenhuizen, GJ Verdier, R Wadsworth, B Wolfs, FLH Woseik, B Wozniak, K Wuosmaa, AH Wyslouch, B CA PHOBOS Collaboration TI Charged-particle pseudorapidity density distributions from Au plus Au collisions at root s(NN)=130 GeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEAR COLLISIONS; ENERGIES; MODEL; PROTON; PP AB The charged-particle pseudorapidity density dN(ch)/d eta has been measured for Au + Au collisions at roots(NN) = 130 GeV at RHIC, using the PHOBOS apparatus. The total number of charged particles produced for the 3% most-central Au + Au collisions for \eta\ less than or equal to 5.4 is found to be 4200 +/- 470. The evolution of dN(ch)/d eta with centrality is discussed, and compared to model calculations and to data from proton-induced collisions. The data show an enhancement in charged-particle production at midrapidity, while in the fragmentation regions, the results are consistent with expectations from pp and pA scattering. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, CA Dept, Upton, NY 11973 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Univ Maryland, Dept Chem & Biochem, College Pk, MD 20742 USA. Inst Nucl Phys, Krakow, Poland. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. Natl Cent Univ, Dept Phys, Chungli 32054, Taiwan. RP Back, BB (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RI Decowski, Patrick/A-4341-2011; Mignerey, Alice/D-6623-2011; Muelmenstaedt, Johannes/K-2432-2015 OI Muelmenstaedt, Johannes/0000-0003-1105-6678 NR 23 TC 168 Z9 171 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2001 VL 87 IS 10 BP art. no. EP 102303 DI 10.1103/PhysRevLett.87.102303 PG 4 WC Physics, Multidisciplinary SC Physics GA 470ZA UT WOS:000170901300012 PM 11531476 ER PT J AU Choi, SM Lynn, JW Lopez, D Gammel, PL Canfield, PC Bud'ko, SL AF Choi, SM Lynn, JW Lopez, D Gammel, PL Canfield, PC Bud'ko, SL TI Direct observation of spontaneous weak ferromagnetism in the superconductor ErNi2B2C SO PHYSICAL REVIEW LETTERS LA English DT Article ID SINGLE-CRYSTAL ERNI2B2C; MAGNETIC ORDER; SPIN; COEXISTENCE; TRANSITION; STATE; SCATTERING; ERRH4B4; PHASE AB Neutron measurements show that superconducting ErNi2B2C (T-c = 11 K) develops anti ferromagnetic spin density wave magnetic order (T-N = 6 K), which squares up with decreasing temperature yielding a series of higher-order magnetic Bragg peaks with odd harmonies. Below T-WFM = 2.3 K where magnetization indicates a net moment develops, even-order Bragg peaks develop which low field (similar to3 Oe) polarized beam measurements show are magnetic in origin. The data directly demonstrate the existence of a net magnetization with a periodicity of 20a, confirming the microscopic coexistence of spontaneous weak ferromagnetism with superconductivity. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Choi, SM (reprint author), Korea Adv Inst Sci & Technol, Dept Nucl Engn, Taejon 305701, South Korea. RI Canfield, Paul/H-2698-2014 NR 32 TC 45 Z9 46 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2001 VL 87 IS 10 BP art. no. EP 107001 DI 10.1103/PhysRevLett.87.107001 PG 4 WC Physics, Multidisciplinary SC Physics GA 470ZA UT WOS:000170901300033 PM 11531497 ER PT J AU Meersschaut, J L'abbe, C Rots, M Bader, SD AF Meersschaut, J L'abbe, C Rots, M Bader, SD TI Origin of biquadratic coupling in Fe/Cr(100) superlattices SO PHYSICAL REVIEW LETTERS LA English DT Article ID DENSITY-WAVE ANTIFERROMAGNETISM; FE/CR(001) SUPERLATTICES; EXCHANGE; MULTILAYERS; CR; CHROMIUM; SPECTROSCOPY; MOMENTS; LAYERS AB We investigate the magnetic properties of a (100) oriented [Fe(1.7 nm)/Cr(8.4 nm)](10) superlattice by means of perturbed angular correlation spectroscopy. The magnetic ordering in the Cr layers is obtained by measuring the magnetic hyperfine interaction at implanted Cd-111 nuclear probes. We identify dynamic antiferromagnetic spin fluctuations in the Cr layers and show that it gives rise to the biquadratic interlayer coupling. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Katholieke Univ Leuven, Inst Kern & Stralingsfys, B-3001 Louvain, Belgium. RP Meersschaut, J (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bader, Samuel/A-2995-2013 NR 29 TC 18 Z9 19 U1 0 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2001 VL 87 IS 10 BP art. no. EP 107201 DI 10.1103/PhysRevLett.87.107201 PG 4 WC Physics, Multidisciplinary SC Physics GA 470ZA UT WOS:000170901300035 PM 11531499 ER PT J AU Schulte, EC Ahmidouch, A Armstrong, CS Arrington, J Asaturyan, R Avery, S Baker, OK Beck, DH Blok, HP Bochna, CW Boeglin, W Bosted, PY Bouwhuis, M Breuer, H Brown, DS Bruell, A Cadman, RV Carlini, R Chant, NS Cochran, A Cole, L Danagoulian, S Day, DB Dunne, JA Dutta, D Ent, R Fenker, HC Fox, B Gan, L Gao, H Garrow, K Gaskell, D Gasparian, A Gessaman, DF Gilman, R Glashausser, C Gueye, P Harvey, M Holt, RJ Jackson, HE Jiang, X Keppel, CE Kinney, ER Liang, Y Lorenzon, W Lung, AF Mack, DJ Markowitz, PE Martin, J McIlhany, K McKee, D Meekins, DG Miller, MA Milner, RG Mitchell, JH Mkrtchyan, H Mueller, BA Nathan, AM Niculescu, G Niculescu, I O'Neill, TG Papavassiliou, V Pate, SF Piercey, RB Potterveld, DH Ransome, RD Reinhold, J Rollinde, E Roos, P Saha, A Sarty, AJ Sawafta, R Segbefia, E Shin, T Stepanyan, S Strauch, S Sutter, MF Tadevosyan, V Tang, L Tieulent, R Uzzle, A Vulcan, WF Wood, SA Xiong, F Yuan, L Zeier, M Zihlmann, B Ziskin, V AF Schulte, EC Ahmidouch, A Armstrong, CS Arrington, J Asaturyan, R Avery, S Baker, OK Beck, DH Blok, HP Bochna, CW Boeglin, W Bosted, PY Bouwhuis, M Breuer, H Brown, DS Bruell, A Cadman, RV Carlini, R Chant, NS Cochran, A Cole, L Danagoulian, S Day, DB Dunne, JA Dutta, D Ent, R Fenker, HC Fox, B Gan, L Gao, H Garrow, K Gaskell, D Gasparian, A Gessaman, DF Gilman, R Glashausser, C Gueye, P Harvey, M Holt, RJ Jackson, HE Jiang, X Keppel, CE Kinney, ER Liang, Y Lorenzon, W Lung, AF Mack, DJ Markowitz, PE Martin, J McIlhany, K McKee, D Meekins, DG Miller, MA Milner, RG Mitchell, JH Mkrtchyan, H Mueller, BA Nathan, AM Niculescu, G Niculescu, I O'Neill, TG Papavassiliou, V Pate, SF Piercey, RB Potterveld, DH Ransome, RD Reinhold, J Rollinde, E Roos, P Saha, A Sarty, AJ Sawafta, R Segbefia, E Shin, T Stepanyan, S Strauch, S Sutter, MF Tadevosyan, V Tang, L Tieulent, R Uzzle, A Vulcan, WF Wood, SA Xiong, F Yuan, L Zeier, M Zihlmann, B Ziskin, V TI Measurement of the high energy two-body deuteron photodisintegration differential cross section SO PHYSICAL REVIEW LETTERS LA English DT Article ID 2-BODY PHOTODISINTEGRATION; QUANTUM CHROMODYNAMICS; ASYMPTOTIC AMPLITUDES; HADRONS; MODEL AB The first measurements of the d(gamma, p)n differential cross section at forward angles and photon energies above 4 GeV were performed at the Thomas Jefferson National Accelerator Facility (JLab). The results indicate evidence of an angular dependent scaling threshold. Results at theta (cm) = 37 degrees are consistent with the constituent counting rules for E-gamma greater than or similar to 4 GeV, while those at 70 degrees are consistent with the constituent counting rules for E-gamma greater than or similar to 1.5 GeV. C1 Univ Illinois, Urbana, IL 61801 USA. N Carolina Agr & Tech State Univ, Greensboro, NC 27411 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Yerevan Phys Inst, Yerevan 375036, Armenia. Hampton Univ, Hampton, VA 23668 USA. Vrije Univ Amsterdam, Amsterdam, Netherlands. Florida Int Univ, Miami, FL 33199 USA. Univ Massachusetts, Amherst, MA 01003 USA. Univ Maryland, College Pk, MD 20742 USA. MIT, Cambridge, MA 02139 USA. Univ Virginia, Charlottesville, VA 22901 USA. Mississippi State Univ, Starkville, MS 39759 USA. Univ Colorado, Boulder, CO 80309 USA. Rutgers State Univ, New Brunswick, NJ 08903 USA. American Univ, Washington, DC 20016 USA. Univ Michigan, Ann Arbor, MI 48109 USA. New Mexico State Univ, Las Cruces, NM 88003 USA. Florida State Univ, Tallahassee, FL 32306 USA. Ohio Univ, Athens, OH 45701 USA. George Washington Univ, Washington, DC 20052 USA. RP Schulte, EC (reprint author), Univ Illinois, Urbana, IL 61801 USA. RI Gao, Haiyan/G-2589-2011; Arrington, John/D-1116-2012; Holt, Roy/E-5803-2011; Sarty, Adam/G-2948-2014; Day, Donal/C-5020-2015 OI Arrington, John/0000-0002-0702-1328; Day, Donal/0000-0001-7126-8934 NR 31 TC 47 Z9 47 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2001 VL 87 IS 10 BP art. no. EP 102302 DI 10.1103/PhysRevLett.87.102302 PG 4 WC Physics, Multidisciplinary SC Physics GA 470ZA UT WOS:000170901300011 PM 11531475 ER PT J AU Zhang, SB Branz, HM AF Zhang, SB Branz, HM TI Hydrogen above saturation at silicon vacancies: H-pair reservoirs and metastability sites SO PHYSICAL REVIEW LETTERS LA English DT Article ID A-SI-H; AMORPHOUS-SILICON; POSITRON-ANNIHILATION; SOLAR-CELLS; MODEL; DEFECTS AB We propose that hydrogen-passivated multivacancies which appear to be fully saturated with H can actually capture additional H in electrically inactive sites. In silicon, first-principles total energy calculations show that splitting an (m greater than or equal to 2) multivacancy into a mono- and an (m - 1) vacancy provides a low-strain pairing site for H, 0.4 eV per H lower than any known bulk pairing site. This monovacancy ejection mechanism is an excellent candidate for the H reservoir found both in crystalline and amorphous Si. A distinct H pairing on the fully saturated in vacancies, by forming an internal surface Si-Si dimer, provides the final state of light-induced metastable degradation of hydrogenated amorphous silicon. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Zhang, SB (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013 OI Zhang, Shengbai/0000-0003-0833-5860 NR 24 TC 33 Z9 33 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2001 VL 87 IS 10 BP art. no. EP 105503 DI 10.1103/PhysRevLett.87.105503 PG 4 WC Physics, Multidisciplinary SC Physics GA 470ZA UT WOS:000170901300021 PM 11531485 ER PT J AU Affolder, T Akimoto, H Akopian, A Albrow, MG Amaral, P Amendolia, SR Amidei, D Anikeev, K Antos, J Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Azfar, F Azzi-Bacchetta, P Bacchetta, N Bailey, MW Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Baroiant, S Barone, M Bauer, G Bedeschi, F Belforte, S Bell, WH Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bevensee, B Bhatti, A Binkley, M Bisello, D Bishai, M Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, SR Bocci, A Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A van den Brink, S Bromberg, C Brozovic, M Bruner, N Buckley-Geer, E Budagov, J Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Calafiura, P Campbell, M Carithers, W Carlson, J Carlsmith, D Caskey, W Cassada, J Castro, A Cauz, D Cerri, A Chan, AW Chang, PS Chang, PT Chapman, J Chen, C Chen, YC Cheng, MT Chertok, M Chiarelli, G Chirikov-Zorin, I Chlachidze, G Chlebana, F Christofek, L Chu, ML Chung, YS Ciobanu, CI Clark, AG Connolly, A Conway, J Cordelli, M Cranshaw, J Cronin-Hennessy, D Cropp, R Culbertson, R Dagenhart, D D'Auria, S DeJongh, F Dell'Agnello, S Dell'Orso, M Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Engels, E Errede, D Errede, S Fan, Q Feild, RG Fernandez, JP Ferretti, C Field, RD Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Fukui, Y Furic, I Galeotti, S Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Gerdes, DW Giannetti, P Giromini, P Glagolev, V Gold, M Goldstein, J Gordon, A Gorelov, I Goshaw, AT Gotra, Y Goulianos, K Green, C Grim, G Gris, P Groer, L Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Haas, RM Haber, C Hafen, E Hahn, SR Hall, C Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hatakeyama, K Hauser, J Heinrich, J Heiss, A Herndon, M Hill, C Hoffman, KD Holck, C Hollebeek, R Holloway, L Hughes, R Huston, J Huth, J Ikeda, H Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kilminster, B Kim, BJ Kim, DH Kim, HS Kim, MJ Kim, SH Kim, YK Kirby, M Kirk, M Kirsch, L Klimenko, S Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korn, A Korytov, A Kovacs, E Kroll, J Kruse, M Kuhlmann, SE Kurino, K Kuwabara, T Laasanen, AT Lai, N Lami, S Lammel, S Lamoureux, JI Lancaster, J Lancaster, M Lander, R Latino, G LeCompte, T Lee, AM Lee, K Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Mariotti, M Martignon, G Martin, A Matthews, JAJ Mayer, J Mazzanti, P McFarland, KS McIntyre, P McKigney, E Menguzzato, M Menzione, A Mesropian, C Meyer, A Miao, T Miller, R Miller, JS Minato, H Miscetti, S Mishina, M Mitselmakher, G Moggi, N Moore, E Moore, R Morita, Y Moulik, T Mulhearn, M Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Nachtman, J Nahn, S Nakada, H Nakaya, T Nakano, I Nelson, C Nelson, T Neu, C Neuberger, D Newman-Holmes, C Ngan, CYP Niu, H Nodulman, L Nomerotski, A Oh, S Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Orejudos, W Pagliarone, C Palmonari, F Paoletti, R Papadimitriou, V Pappas, SP Partos, D Patrick, J Pauletta, G Paulini, M Paus, C Pescara, L Phillips, TJ Piacentino, G Pitts, KT Pompos, A Pondrom, L Pope, G Popovic, M Prokoshin, F Proudfoot, J Ptohos, F Pukhov, O Punzi, G Ragan, K Rakitine, A Reher, D Reichold, A Ribon, A Reigler, W Rimondi, F Ristori, L Riveline, M Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Roy, A Safonov, A St Denis, R Sakumoto, WK Saltzberg, D Sanchez, C Sansoni, A Santi, L Sato, H Savard, P Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Scodellaro, L Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semenov, A Semeria, F Shah, T Shapiro, MD Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Signorelli, G Sill, A Sinervo, P Singh, P Slaughter, AJ Sliwa, K Smith, C Snider, FD Solodsky, A Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, T Takano, T Takashima, R Takikawa, K Tamburello, P Tanaka, M Tannenbaum, B Taylor, W Tecchio, M Teng, PK Terashi, K Tether, S Thompson, AS Thurman-Keup, R Tipton, P Tkaczyk, S Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Tseng, J Turini, N Ukegawa, F Vaiciulis, T Valls, J Vejcik, S Velev, G Vidal, R Vilar, R Volobouev, I Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, MJ Watanabe, T Waters, D Watts, T Webb, R Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkes, T Williams, HH Wilson, P Winer, BL Winn, D Wolbers, S Wolinski, D Wolinski, J Wolinski, S Worm, S Wu, X Wyss, J Yagil, A Yao, W Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Yu, S Yu, Z Zanetti, A Zetti, F Zucchelli, S AF Affolder, T Akimoto, H Akopian, A Albrow, MG Amaral, P Amendolia, SR Amidei, D Anikeev, K Antos, J Apollinari, G Arisawa, T Asakawa, T Ashmanskas, W Azfar, F Azzi-Bacchetta, P Bacchetta, N Bailey, MW Bailey, S de Barbaro, P Barbaro-Galtieri, A Barnes, VE Barnett, BA Baroiant, S Barone, M Bauer, G Bedeschi, F Belforte, S Bell, WH Bellettini, G Bellinger, J Benjamin, D Bensinger, J Beretvas, A Berge, JP Berryhill, J Bevensee, B Bhatti, A Binkley, M Bisello, D Bishai, M Blair, RE Blocker, C Bloom, K Blumenfeld, B Blusk, SR Bocci, A Bodek, A Bokhari, W Bolla, G Bonushkin, Y Bortoletto, D Boudreau, J Brandl, A van den Brink, S Bromberg, C Brozovic, M Bruner, N Buckley-Geer, E Budagov, J Budd, HS Burkett, K Busetto, G Byon-Wagner, A Byrum, KL Calafiura, P Campbell, M Carithers, W Carlson, J Carlsmith, D Caskey, W Cassada, J Castro, A Cauz, D Cerri, A Chan, AW Chang, PS Chang, PT Chapman, J Chen, C Chen, YC Cheng, MT Chertok, M Chiarelli, G Chirikov-Zorin, I Chlachidze, G Chlebana, F Christofek, L Chu, ML Chung, YS Ciobanu, CI Clark, AG Connolly, A Conway, J Cordelli, M Cranshaw, J Cronin-Hennessy, D Cropp, R Culbertson, R Dagenhart, D D'Auria, S DeJongh, F Dell'Agnello, S Dell'Orso, M Demortier, L Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Eddy, N Einsweiler, K Elias, JE Engels, E Errede, D Errede, S Fan, Q Feild, RG Fernandez, JP Ferretti, C Field, RD Fiori, I Flaugher, B Foster, GW Franklin, M Freeman, J Friedman, J Fukui, Y Furic, I Galeotti, S Gallinaro, M Gao, T Garcia-Sciveres, M Garfinkel, AF Gatti, P Gay, C Gerdes, DW Giannetti, P Giromini, P Glagolev, V Gold, M Goldstein, J Gordon, A Gorelov, I Goshaw, AT Gotra, Y Goulianos, K Green, C Grim, G Gris, P Groer, L Grosso-Pilcher, C Guenther, M Guillian, G da Costa, JG Haas, RM Haber, C Hafen, E Hahn, SR Hall, C Handa, T Handler, R Hao, W Happacher, F Hara, K Hardman, AD Harris, RM Hartmann, F Hatakeyama, K Hauser, J Heinrich, J Heiss, A Herndon, M Hill, C Hoffman, KD Holck, C Hollebeek, R Holloway, L Hughes, R Huston, J Huth, J Ikeda, H Incandela, J Introzzi, G Iwai, J Iwata, Y James, E Jensen, H Jones, M Joshi, U Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Kelley, K Kelly, M Kennedy, RD Kephart, R Khazins, D Kikuchi, T Kilminster, B Kim, BJ Kim, DH Kim, HS Kim, MJ Kim, SH Kim, YK Kirby, M Kirk, M Kirsch, L Klimenko, S Koehn, P Kongeter, A Kondo, K Konigsberg, J Kordas, K Korn, A Korytov, A Kovacs, E Kroll, J Kruse, M Kuhlmann, SE Kurino, K Kuwabara, T Laasanen, AT Lai, N Lami, S Lammel, S Lamoureux, JI Lancaster, J Lancaster, M Lander, R Latino, G LeCompte, T Lee, AM Lee, K Leone, S Lewis, JD Lindgren, M Liss, TM Liu, JB Liu, YC Lockyer, N Loken, J Loreti, M Lucchesi, D Lukens, P Lusin, S Lyons, L Lys, J Madrak, R Maeshima, K Maksimovic, P Malferrari, L Mangano, M Mariotti, M Martignon, G Martin, A Matthews, JAJ Mayer, J Mazzanti, P McFarland, KS McIntyre, P McKigney, E Menguzzato, M Menzione, A Mesropian, C Meyer, A Miao, T Miller, R Miller, JS Minato, H Miscetti, S Mishina, M Mitselmakher, G Moggi, N Moore, E Moore, R Morita, Y Moulik, T Mulhearn, M Mukherjee, A Muller, T Munar, A Murat, P Murgia, S Nachtman, J Nahn, S Nakada, H Nakaya, T Nakano, I Nelson, C Nelson, T Neu, C Neuberger, D Newman-Holmes, C Ngan, CYP Niu, H Nodulman, L Nomerotski, A Oh, S Ohmoto, T Ohsugi, T Oishi, R Okusawa, T Olsen, J Orejudos, W Pagliarone, C Palmonari, F Paoletti, R Papadimitriou, V Pappas, SP Partos, D Patrick, J Pauletta, G Paulini, M Paus, C Pescara, L Phillips, TJ Piacentino, G Pitts, KT Pompos, A Pondrom, L Pope, G Popovic, M Prokoshin, F Proudfoot, J Ptohos, F Pukhov, O Punzi, G Ragan, K Rakitine, A Reher, D Reichold, A Ribon, A Reigler, W Rimondi, F Ristori, L Riveline, M Robertson, WJ Robinson, A Rodrigo, T Rolli, S Rosenson, L Roser, R Rossin, R Roy, A Safonov, A St Denis, R Sakumoto, WK Saltzberg, D Sanchez, C Sansoni, A Santi, L Sato, H Savard, P Schlabach, P Schmidt, EE Schmidt, MP Schmitt, M Scodellaro, L Scott, A Scribano, A Segler, S Seidel, S Seiya, Y Semenov, A Semeria, F Shah, T Shapiro, MD Shepard, PF Shibayama, T Shimojima, M Shochet, M Siegrist, J Signorelli, G Sill, A Sinervo, P Singh, P Slaughter, AJ Sliwa, K Smith, C Snider, FD Solodsky, A Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Steele, J Stefanini, A Strologas, J Strumia, F Stuart, D Sumorok, K Suzuki, T Takano, T Takashima, R Takikawa, K Tamburello, P Tanaka, M Tannenbaum, B Taylor, W Tecchio, M Teng, PK Terashi, K Tether, S Thompson, AS Thurman-Keup, R Tipton, P Tkaczyk, S Tollefson, K Tollestrup, A Toyoda, H Trischuk, W de Troconiz, JF Tseng, J Turini, N Ukegawa, F Vaiciulis, T Valls, J Vejcik, S Velev, G Vidal, R Vilar, R Volobouev, I Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, NB Walsh, AM Wang, C Wang, MJ Watanabe, T Waters, D Watts, T Webb, R Wenzel, H Wester, WC Wicklund, AB Wicklund, E Wilkes, T Williams, HH Wilson, P Winer, BL Winn, D Wolbers, S Wolinski, D Wolinski, J Wolinski, S Worm, S Wu, X Wyss, J Yagil, A Yao, W Yeh, GP Yeh, P Yoh, J Yosef, C Yoshida, T Yu, I Yu, S Yu, Z Zanetti, A Zetti, F Zucchelli, S CA CDF Collaboration TI Measurement of the top quark p(T) distribution SO PHYSICAL REVIEW LETTERS LA English DT Article ID COLLIDER DETECTOR; (P)OVER-BAR-P COLLISIONS; PHYSICS; FERMILAB; MASS AB We have measured the p(T) distribution of top quarks that are pair produced in p (p) over bar collisions at roots = 1.8 TeV using a sample of t (t) over bar decays in which we observe a single high-P-T charged lepton, a neutrino, and four or more jets. We use a likelihood technique that corrects for the experimental bias introduced due to event reconstruction and detector resolution effects. The observed distribution is consistent with the standard model prediction. We use these data to place limits on the production of high-p(T) top quarks suggested in some models of anomalous top quark pair production. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Acad Sinica, Inst Phys, Taipei 11529, Taiwan. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Bologna, Ist Nazl Fis Nucl, I-40127 Bologna, Italy. Brandeis Univ, Waltham, MA 02254 USA. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Cantabria, CSIC, Inst Fis Cantabria, E-39005 Santander, Spain. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Joint Inst Nucl Res, RU-141980 Dubna, Russia. Duke Univ, Durham, NC 27708 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Florida, Gainesville, FL 32611 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Geneva, CH-1211 Geneva 4, Switzerland. Univ Glasgow, Glasgow G12 8QQ, Lanark, Scotland. Harvard Univ, Cambridge, MA 02138 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Univ Illinois, Urbana, IL 61801 USA. Johns Hopkins Univ, Baltimore, MD 21218 USA. Univ Karlsruhe, Inst Expt Kernphys, D-76128 Karlsruhe, Germany. Kyungpook Natl Univ, Ctr High Energy Phys, Taegu 702701, South Korea. Seoul Natl Univ, Seoul 151742, South Korea. Sungkyunkwan Univ, Suwon 440746, South Korea. High Energy Accelerator Res Org, Tsukuba, Ibaraki 305, Japan. MIT, Cambridge, MA 02139 USA. McGill Univ, Inst Particle Phys, Montreal, PQ H3A 2T8, Canada. Univ Toronto, Toronto, ON M5S 1A7, Canada. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ New Mexico, Albuquerque, NM 87131 USA. Ohio State Univ, Columbus, OH 43210 USA. Osaka City Univ, Osaka 588, Japan. Univ Oxford, Oxford OX1 3RH, England. Univ Padua, Ist Nazl Fis Nucl, Sez Padova, I-35131 Padua, Italy. Univ Penn, Philadelphia, PA 19104 USA. Univ Pisa, Ist Nazl Fis Nucl, I-56100 Pisa, Italy. Scuola Normale Super Pisa, I-56100 Pisa, Italy. Univ Pittsburgh, Pittsburgh, PA 15260 USA. Purdue Univ, W Lafayette, IN 47907 USA. Univ Rochester, Rochester, NY 14627 USA. Rockefeller Univ, New York, NY 10021 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Texas A&M Univ, College Stn, TX 77843 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Univ Trieste Udine, Ist Nazl Fis Nucl, Udine, Italy. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Tufts Univ, Medford, MA 02155 USA. Waseda Univ, Tokyo 169, Japan. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06520 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Scodellaro, Luca/K-9091-2014; Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Nomerotski, Andrei/A-5169-2010; Ruiz, Alberto/E-4473-2011; St.Denis, Richard/C-8997-2012; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Kim, Soo-Bong/B-7061-2014; Gallas Torreira, Abraham Antonio/K-6508-2014; Paulini, Manfred/N-7794-2014; vilar, rocio/P-8480-2014; Cabrera Urban, Susana/H-1376-2015; Introzzi, Gianluca/K-2497-2015; Gorelov, Igor/J-9010-2015; Prokoshin, Fedor/E-2795-2012; OI Scodellaro, Luca/0000-0002-4974-8330; Ruiz, Alberto/0000-0002-3639-0368; Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Gallas Torreira, Abraham Antonio/0000-0002-2745-7954; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580; Gorelov, Igor/0000-0001-5570-0133; Prokoshin, Fedor/0000-0001-6389-5399; Lami, Stefano/0000-0001-9492-0147; CHANG, PAO-TI/0000-0003-4064-388X; Signorelli, Giovanni/0000-0001-8262-8245; Goldstein, Joel/0000-0003-1591-6014 NR 20 TC 67 Z9 68 U1 2 U2 9 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2001 VL 87 IS 10 AR 102001 DI 10.1103/PhysRevLett.87.102001 PG 6 WC Physics, Multidisciplinary SC Physics GA 470ZA UT WOS:000170901300009 PM 11736493 ER PT J AU Back, BB Baker, MD Barton, DS Betts, RR Bindel, R Budzanowski, A Busza, W Carroll, A Decowski, MP Garcia, E George, N Gulbrandsen, K Gushue, S Halliwell, C Heintzelman, GA Henderson, C Holynski, R Hofman, D Holzman, B Johnson, E Kane, J Katzy, J Khan, N Kucewicz, W Kulinich, P Lin, WT Manly, S McLeod, D Michalowski, J Mignerey, A Mulmenstadt, J Nouicer, R Olszewski, A Pak, R Park, IC Pernegger, H Reed, C Remsberg, LP Reuter, M Roland, C Roland, G Rosenberg, L Sarin, P Sawicki, P Skulski, W Steadman, SG Stephans, GSF Steinberg, P Stodulski, M Sukhanov, A Tang, JL Teng, R Trzupek, A Vale, C van Nieuwenhuizen, GJ Verdier, R Wadsworth, B Wolfs, FLH Wosiek, B Wozniak, K Wuosmaa, AH Wyslouch, B AF Back, BB Baker, MD Barton, DS Betts, RR Bindel, R Budzanowski, A Busza, W Carroll, A Decowski, MP Garcia, E George, N Gulbrandsen, K Gushue, S Halliwell, C Heintzelman, GA Henderson, C Holynski, R Hofman, D Holzman, B Johnson, E Kane, J Katzy, J Khan, N Kucewicz, W Kulinich, P Lin, WT Manly, S McLeod, D Michalowski, J Mignerey, A Mulmenstadt, J Nouicer, R Olszewski, A Pak, R Park, IC Pernegger, H Reed, C Remsberg, LP Reuter, M Roland, C Roland, G Rosenberg, L Sarin, P Sawicki, P Skulski, W Steadman, SG Stephans, GSF Steinberg, P Stodulski, M Sukhanov, A Tang, JL Teng, R Trzupek, A Vale, C van Nieuwenhuizen, GJ Verdier, R Wadsworth, B Wolfs, FLH Wosiek, B Wozniak, K Wuosmaa, AH Wyslouch, B CA PHOBOS Collaboration TI Ratios of charged antiparticles-to-particles near mid-rapidity in Au plus Au collisions at root s(NN)=130 GeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID PB COLLISIONS AB We have measured the ratios of antiparticles to particles for charged pions, kaons, and protons near mid-rapidity in central Au + Au collisions at roots(NN) = 130 GeV. We observe (pi (-))/(pi (+)) = 1.00 +/- 0.01(stat) +/- 0.02(syst), (K-)/(K+) = 0.91 +/- 0.07(stat) +/- 0.06(syst), and [(p) over bar)/(p) = 0.60 +/- 0.04(stat) +/- 0.06(syst). The (K-)/(K+) and ((p) over bar)/(p) ratios give a consistent estimate of the baryo-chemical potential mu (B) of 45 MeV, a factor of 5-6 smaller than in central Pb + Pb collisions at roots(NN) = 17.2 GeV. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, CA Dept, Upton, NY 11973 USA. Inst Nucl Phys, Krakow, Poland. MIT, Nucl Sci Lab, Cambridge, MA 02139 USA. Natl Cent Univ, Dept Phys, Chungli 32054, Taiwan. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Univ Rochester, Dept Phys & Astron, Rochester, NY 14627 USA. RP Back, BB (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RI Decowski, Patrick/A-4341-2011; Mignerey, Alice/D-6623-2011; seto, richard/G-8467-2011; Cumming, James/I-3358-2013; Muelmenstaedt, Johannes/K-2432-2015 OI Cumming, James/0000-0001-6930-0958; Muelmenstaedt, Johannes/0000-0003-1105-6678 NR 22 TC 81 Z9 81 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2001 VL 87 IS 10 AR 102301 DI 10.1103/PhysRevLett.87.102301 PG 4 WC Physics, Multidisciplinary SC Physics GA 470ZA UT WOS:000170901300010 PM 11531474 ER PT J AU Bec, M AF Bec, M TI Universality of velocity gradients in forced Burgers turbulence SO PHYSICAL REVIEW LETTERS LA English DT Article ID EQUATION AB We demonstrate that Burgers turbulence subject to large-scale white-noise-in-time random forcing has a universal power-law tail with exponent -7/2 in the probability density function of negative velocity gradients, as predicted by E, Khanin, Mazel, and Sinai [Phys. Rev. Lett. 78, 1904 (1997)]. A particle and shock tracking numerical method gives about five decades of scaling. Using a Lagrangian approach. the -7/2 law is related to the shape of the unstable manifold associated to the global minimizer. C1 Observ Cote Azur, Lab GD Cassini, F-06304 Nice 4, France. Los Alamos Natl Lab, Div Theoret, CNLS, Los Alamos, NM 87545 USA. RP Observ Cote Azur, Lab GD Cassini, BP 4229, F-06304 Nice 4, France. EM bec@obs-nice.fr NR 20 TC 0 Z9 0 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2001 VL 87 IS 10 AR 104501 DI 10.1103/PhysRevLett.87.104501 PG 4 WC Physics, Multidisciplinary SC Physics GA 470ZA UT WOS:000170901300017 ER PT J AU VanZeeland, M Gekelman, W Vincena, S Dimonte, G AF VanZeeland, M Gekelman, W Vincena, S Dimonte, G TI Production of Alfven waves by a rapidly expanding dense plasma SO PHYSICAL REVIEW LETTERS LA English DT Article ID CORONAL MASS EJECTIONS; GEOMAGNETIC-ACTIVITY; INJECTION; SOLAR AB The expansion of a dense (initially, nl(pp)/n(o) >> 1) laser-produced plasma into an ambient magnetized plasma (n(o) = 2 x 10(12) cm(-3)) capable of supporting Alfven waves has been studied. The interaction results in the production of shear Alfven waves as well as large density perturbations (Deltan/n(o) similar to 0.3) associated with the moving dense plasma. The waves propagate away from the target and are observed to become plasma-column resonances. Spatial patterns of the wave magnetic fields are measured and are used to estimate the coupling efficiency of the laser energy and the kinetic energy of the dense plasma into wave energy. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP VanZeeland, M (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. NR 20 TC 33 Z9 33 U1 3 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD SEP 3 PY 2001 VL 87 IS 10 AR 105001 DI 10.1103/PhysRevLett.87.105001 PG 4 WC Physics, Multidisciplinary SC Physics GA 470ZA UT WOS:000170901300018 PM 11531482 ER PT J AU Vikhnin, VS Liu, GK Beitz, JV AF Vikhnin, VS Liu, GK Beitz, JV TI Laser-induced "charge transfer-lattice" clusters and site-conversion near charged impurities SO PHYSICS LETTERS A LA English DT Article DE charge transfer vibronic exciton; charged impurity; site conversion; multi-site phenomenon; cross-relaxation; memory effects ID TRANSFER VIBRONIC EXCITONS; PEROVSKITE-LIKE FERROELECTRICS; POLAR MICRODOMAINS; MULLER PHASE; ORIGIN AB Theoretical analysis of the laser excitation-induced conversion of the sites accompanied by memory effect both caused by Eu3+ impurities in BaFCl crystal was performed. A model based on a new type self-consistent "charge transfer-lattice distortion" states induced by charged impurities in their vicinity was considered in this connection. Here impurity field increases an equilibrium charge transfer with appearance of charge transfer vibronic exciton (CTVE) states. The origin of the phenomenon was explained as a result of cross-relaxation between CTVE trapped by impurity on the one hand and excited states of this impurity on the other. (C) 2001 Elsevier Science B.V. All rights reserved. C1 AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP AF Ioffe Phys Tech Inst, St Petersburg 194021, Russia. EM valentin.vikhnin@physik.uni-osnabrueck.de NR 10 TC 14 Z9 14 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 EI 1873-2429 J9 PHYS LETT A JI Phys. Lett. A PD SEP 3 PY 2001 VL 287 IS 5-6 BP 419 EP 425 DI 10.1016/S0375-9601(01)00509-6 PG 7 WC Physics, Multidisciplinary SC Physics GA 472LA UT WOS:000170984500020 ER PT J AU Mahan, AH Schropp, REI AF Mahan, AH Schropp, REI TI Cat-CVD (Hot-Wire CVD) Process - Proceedings of the First International Conference on Cat-CVD (Hot-Wire CVD) Process - Kanazawa, Japan - November 14-17, 2000 - Preface SO THIN SOLID FILMS LA English DT Editorial Material C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Utrecht, Debye Inst, NL-3508 TA Utrecht, Netherlands. RP Mahan, AH (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. RI Schropp, Ruud/C-6410-2009; Schropp, Ruud/I-7374-2012; Institute (DINS), Debye/G-7730-2014 OI Schropp, Ruud/0000-0003-4175-2658; NR 0 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 3 PY 2001 VL 395 IS 1-2 BP IX EP XI PG 3 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 483GJ UT WOS:000171625000001 ER PT J AU Mahan, AH AF Mahan, AH TI Status of Cat-CVD (Hot Wire CVD) research in the United States SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 1st International Conference on Cat-CVD (Hot Wire CVD) Process CY NOV 14-17, 2000 CL KANAZAWA, JAPAN DE hot filament CVD; gSi : H; mu c-Si; solar cells; deposition chemistry ID A-SI-H; AMORPHOUS-SILICON; DEPOSITION; QUALITY; HYDROGEN; SILANE; GROWTH; FILMS AB The status of Cat-CVD (Hot Wire CVD) research in the United States is presented. This paper is divided into two topics. Firstly, the status of Si-based Cat-CVD research is presented. For this topic, a short history of previous research in this field is given. This will serve to illustrate the increasing level of interest in this new and exciting field. This part includes both hydrogenated amorphous silicon (a-Si:H) as well as microcrystalline silicon (muc-Si) based materials. Although a heavy emphasis upon basic research will be shown, device work is also included. The second (very brief) topic includes research outside of Si-based materials. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Mahan, AH (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 27 TC 32 Z9 33 U1 0 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 3 PY 2001 VL 395 IS 1-2 BP 12 EP 16 DI 10.1016/S0040-6090(01)01199-3 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 483GJ UT WOS:000171625000003 ER PT J AU Crandall, RS Liu, X AF Crandall, RS Liu, X TI Elastic properties of amorphous and nanocrystalline silicon SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 1st International Conference on Cat-CVD (Hot Wire CVD) Process CY NOV 14-17, 2000 CL KANAZAWA, JAPAN DE internal friction; thermal conductivity; amorphous silicon; hot-wire chemical-vapor deposition ID A-SI-H; THERMAL-PROPERTIES; QUALITY; EXCITATIONS; DEPOSITION; SOLIDS; FILMS; GE AB We review the resent status of the elastic properties of amorphous silicon (a-Si) and germanium (a-Ge) thin films produced by either plasma-assisted chemical-vapor-deposition (PECVD) or hot-wire (cat) CVD (HWCVD). Using an extremely sensitive c-Si mechanical oscillator, we measure the low temperature oscillator damping for a variety of amorphous and nanocrystalline Si thin films deposited on the oscillator and thus determine their internal friction. This internal friction is a direct measure of the phonon loss mechanisms. We find that HWCVD a-Si with H content below approximately 3 at.% is the first example that the usual two-level tunneling states (TLS) found in all amorphous solids can be reduced by nearly three orders of magnitude. However, the TLS are present in a-Si prepared by other methods. This low H material also shows an enhanced resistance to the Staebler-Wronski effect. We will present results of light soaking on the elastic properties of both HWCVD and PECVD a-Si. Although the low temperature elastic properties Of PECVD and HWCVD are significantly different, their room temperature thermal conductivity is virtually the same. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. SFA Inc, Largo, MD 20774 USA. RP Crandall, RS (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 16 TC 2 Z9 2 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 3 PY 2001 VL 395 IS 1-2 BP 78 EP 83 DI 10.1016/S0040-6090(01)01212-3 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 483GJ UT WOS:000171625000016 ER PT J AU Han, DX Yue, GZ Habuchi, H Iwaniczko, E Wang, Q AF Han, DX Yue, GZ Habuchi, H Iwaniczko, E Wang, Q TI Electronic states and the light-induced metastability in hydrogenated amorphous silicon prepared by hot-wire CVD SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 1st International Conference on Cat-CVD (Hot Wire CVD) Process CY NOV 14-17, 2000 CL KANAZAWA, JAPAN DE electronic states; metastability; hydrogenated amorphous silicon AB We found that the improved structural order in hydrogenated amorphous silicon (a-Si:H) deposited by hot-wire chemical vapor deposition (HW-CVD) does not result in narrowing of the electronic band tail density of states. However, the features of light-induced effects are different from those in glow-discharge (GD-CVD) films. Upon light-soaking, (a) the photoconductivity (PC) does not change significantly, and (b) the Fermi level position moves up rather than down in most samples. These results are discussed in the context of possible defect complexes existing in an inhomogeneous network. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. Figu Natl Coll Technol, Gifu 5010495, Japan. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Han, DX (reprint author), Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. NR 3 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 3 PY 2001 VL 395 IS 1-2 BP 134 EP 137 DI 10.1016/S0040-6090(01)01235-4 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 483GJ UT WOS:000171625000028 ER PT J AU Fortmann, CM Jaen, EL Hata, N Anderson, WA Mahan, AH AF Fortmann, CM Jaen, EL Hata, N Anderson, WA Mahan, AH TI Hot-wire deposition of photonic-grade amorphous silicon SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 1st International Conference on Cat-CVD (Hot Wire CVD) Process CY NOV 14-17, 2000 CL KANAZAWA, JAPAN DE amorphous silicon; hot-wire deposition; photonic device AB A new amorphous silicon application related to the patterning of refractive index for the purpose of defining and integrating photonic-device elements is emerging. Photonic device elements include waveguides, splitters, mirrors, optical memories, etc. Hot-wire-deposited amorphous silicon has several attributes that make it an exceedingly attractive matrix for photonic device patterning, including: high hydrogen solubility limits; relatively little sub-gap absorption; low stress; non-peeling films; and fast, economical deposition of thick (greater than or equal to5 mum) films, as well as optically smooth as-deposited surfaces, even on thick films. The growing catalog of proposed and/or demonstrated amorphous silicon-based optical devices is rapidly expanding. (C) 2001 Elsevier Science B.V. All rights reserved. C1 SUNY Stony Brook, Dept Appl Math, Stony Brook, NY 11794 USA. Electrotech Lab, Div Mat Sci, Tsukuba, Ibaraki 3058568, Japan. SUNY Buffalo, Dept Elect Engn, Buffalo, NY 14260 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Fortmann, CM (reprint author), SUNY Stony Brook, Dept Appl Math, Stony Brook, NY 11794 USA. RI Hata, Nobuhiro/F-9579-2014 OI Hata, Nobuhiro/0000-0002-8132-0895 NR 13 TC 7 Z9 7 U1 1 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 3 PY 2001 VL 395 IS 1-2 BP 142 EP 146 DI 10.1016/S0040-6090(01)01239-1 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 483GJ UT WOS:000171625000030 ER PT J AU Nelson, BP Iwaniczko, E Mahan, AH Wang, Q Xu, YQ Crandall, RS Branz, HM AF Nelson, BP Iwaniczko, E Mahan, AH Wang, Q Xu, YQ Crandall, RS Branz, HM TI High-deposition rate a-Si : H n-i-p solar cells grown by HWCVD SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 1st International Conference on Cat-CVD (Hot Wire CVD) Process CY NOV 14-17, 2000 CL KANAZAWA, JAPAN DE amorphous materials; silicon; solar cells; deposition process ID HYDROGENATED AMORPHOUS-SILICON; HOT-WIRE CVD; QUALITY AB We grow hydrogenated amorphous silicon (a-Si:H) solar cells in a device structure denoted as SS/n-i-p/ITO. We grow all the a-Si:H layers by hot-wire chemical vapor deposition (HWCVD) and the indium-tin-oxide (ITO) by reactive evaporation. We axe able to grow HWCVD i-layer materials that maintain an AM1.5 photoconductivity-to-dark-conductivity ratio of 10(5) at deposition rates up to 130 Angstrom /s. We have put these high-deposition rate i-layer materials into SS/n-i-p/ITO devices and light-soaked them for greater than or equal to 1000 h under AM1.5 conditions. We obtain stabilized solar cell efficiencies of 5.5% at 18 Angstrom /s, 4.8% at 35 Angstrom /s, 4.1% at 83 Angstrom /s and 3.8% at 127 Angstrom /s. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Nelson, BP (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 20 TC 39 Z9 40 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD SEP 3 PY 2001 VL 395 IS 1-2 BP 292 EP 297 DI 10.1016/S0040-6090(01)01274-3 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 483GJ UT WOS:000171625000062 ER PT J AU Shea, KJ Loy, DA AF Shea, KJ Loy, DA TI A mechanistic investigation of gelation. The sol-gel polymerization of precursors to bridged polysilsesquioxanes SO ACCOUNTS OF CHEMICAL RESEARCH LA English DT Review ID ORGANIC-INORGANIC MATERIALS; INTRAMOLECULAR CONDENSATION-REACTIONS; CYCLIC DISILSESQUIOXANES; POROSITY; ALPHA,OMEGA-BIS(TRIETHOXYSILYL)ALKANES; CYCLIZATION; POLYMERS; XEROGELS AB The study of a homologous series of precursors to bridged polysilsesquioxanes has uncovered striking discontinuities in gelation behavior. An investigation of the chemistry during the early stages of the polymerization has provided a molecular basis for these observations. Monomers containing from one to four bridging carbon atoms exhibit a pronounced tendency to undergo rapid intra- or bimolecular cyclization. The cyclic and bicyclic intermediates have been characterized by Si-29 NMR spectroscopy, chemical ionization mass spectrometry, and isolation from the reaction solution. These carbosiloxanes are local thermodynamic sinks that produce kinetic bottlenecks in the production of high-molecular-weight silsesquioxanes. The formation of cyclic carbosiloxanes results in slowing, or in some cases completely shutting down, gelation. An additional finding is that the cyclic structures are incorporated intact into the final xerogel. C1 Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. Sandia Natl Labs, Micrototal Analyt Syst Dept, Albuquerque, NM 87185 USA. RP Shea, KJ (reprint author), Univ Calif Irvine, Dept Chem, Irvine, CA 92697 USA. RI Loy, Douglas/D-4847-2009 OI Loy, Douglas/0000-0001-7635-9958 NR 39 TC 97 Z9 100 U1 4 U2 32 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0001-4842 J9 ACCOUNTS CHEM RES JI Accounts Chem. Res. PD SEP PY 2001 VL 34 IS 9 BP 707 EP 716 DI 10.1021/ar000109b PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 476AW UT WOS:000171204900003 PM 11560470 ER PT J AU Hang, HC Bertozzi, CR AF Hang, HC Bertozzi, CR TI Chemoselective approaches to glycoprotein assembly SO ACCOUNTS OF CHEMICAL RESEARCH LA English DT Review ID EXPRESSED PROTEIN LIGATION; O-LINKED GLYCOPEPTIDES; SOLID-PHASE SYNTHESIS; SIALIC-ACID RESIDUES; CHEMOENZYMATIC SYNTHESIS; KETONE GROUPS; GLYCOSYLATION; PEPTIDES; CYSTEINE; OLIGOSACCHARIDES AB Oligosaccharides on proteins and lipids play central roles in human health and disease. The molecular analysis of glycoconjugate function has benefited tremendously from new methods for their chemical synthesis, which provides homogeneous material not attainable from biosynthetic systems. Still, glycoconjugate synthesis requires the manipulation of multiple stereocenters and protecting groups and remains the domain of a few expert laboratories around the world. This Account summarizes chemoselective approaches for assembling homogeneous glycoconjugates that attempt to reduce the barriers to their synthesis. The objective of these methods is to make glycoconjugate synthesis accessible to a broader community, thereby accelerating progress in glycobiology. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Dept Mol & Cell Biol,Mat Sci Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Dept Chem,Mat Sci Div, Berkeley, CA 94720 USA. Howard Hughes Med Inst, Berkeley, CA 94720 USA. RP Bertozzi, CR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Adv Mat, Dept Mol & Cell Biol,Mat Sci Div, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM58867] NR 49 TC 142 Z9 145 U1 2 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0001-4842 J9 ACCOUNTS CHEM RES JI Accounts Chem. Res. PD SEP PY 2001 VL 34 IS 9 BP 727 EP 736 DI 10.1021/ar9901570 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 476AW UT WOS:000171204900005 PM 11560472 ER PT J AU Benson, SJ McInnes, LC More, JJ AF Benson, SJ McInnes, LC More, JJ TI A case study in the performance and scalability of optimization algorithms SO ACM TRANSACTIONS ON MATHEMATICAL SOFTWARE LA English DT Article DE algorithms; performance; bound-constrained; conjugate gradients; efficiency; gradient projection; high-performance architectures; scalability AB We analyze the performance and scalabilty of algorithms for the solution of large optimization problems on high-performance parallel architectures. Our case study uses the GPCG (gradient projection, conjugate gradient) algorithm for solving bound-constrained convex quadratic problems. Our implementation of the GPCG algorithm within the Toolkit for Advanced Optimization (TAO) is available for a wide range of high-performance architectures and has been tested on problems with over 2.5 million variables. We analyze the performance as a function of the number of variables, the number of free variables, and the preconditioner. In addition, we discuss how the software design facilitates algorithmic comparisons. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Benson, SJ (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. EM more@mcs.anl.gov NR 17 TC 17 Z9 17 U1 0 U2 1 PU ASSOC COMPUTING MACHINERY PI NEW YORK PA 1515 BROADWAY, NEW YORK, NY 10036 USA SN 0098-3500 J9 ACM T MATH SOFTWARE JI ACM Trans. Math. Softw. PD SEP PY 2001 VL 27 IS 3 BP 361 EP 376 DI 10.1145/502800.502805 PG 16 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 517AM UT WOS:000173589000005 ER PT J AU Mocella, V Epelboin, Y Guigay, JP Hartwig, J AF Mocella, V Epelboin, Y Guigay, JP Hartwig, J TI Applications of dynamical diffraction under locally plane wave conditions: defects in nearly perfect crystals and X-ray refractometry SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article ID ANOMALOUS SCATTERING FACTORS; SYNCHROTRON-RADIATION; CONTRAST; SILICON; REFRACTION; TOPOGRAPHY; AMPLITUDE; COHERENCE; PRISM AB In a previous paper, the concept of a locally plane wave was explained theoretically. In such a configuration, the fringe pattern recorded on the film can be considered as a phase analyser. Here the experimental analysis is presented, showing examples of interesting applications to X-ray refractometry and to the visualization of the strain field around isolated defects. C1 Argonne Natl Lab, Adv Photon Source, User Program Div, Argonne, IL 60439 USA. European Synchrotron Radiat Facil, INFM, Operat Grp Grenoble, F-38043 Grenoble, France. Univ Paris 06, Lab Mineral Cristallog, CNRS, URA 009, F-75252 Paris, France. Univ D Diderot, Lab Mineral Cristallog, CNRS, URA 009, F-75252 Paris 05, France. RP Mocella, V (reprint author), Argonne Natl Lab, Adv Photon Source, User Program Div, Argonne, IL 60439 USA. NR 37 TC 2 Z9 2 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD SEP PY 2001 VL 57 BP 526 EP 530 DI 10.1107/S0108767301006985 PN 5 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 468UT UT WOS:000170777100006 PM 11526301 ER PT J AU Szoke, A AF Szoke, A TI Diffraction of partially coherent X-rays and the crystallographic phase problem SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article ID HOLOGRAPHIC METHODS; ATOMIC-RESOLUTION; SCATTERING; IMAGES; BEAM AB This paper proposes a new physical method for the partial solution of the crystallographic phase problem by illuminating the crystal with an X-ray beam of limited coherence. The diffraction spots broaden and, if the coherence length of the incident beam is small enough in all three dimensions, the diffraction pattern becomes continuous. Independent information about the structure is then available both at the Bragg angles and at angles that do not satisfy the Bragg conditions. Under certain conditions, the total information is sufficient to solve the crystal structure ab initio. Two prescriptions for producing X-ray beams with limited coherence are given. C1 Univ Uppsala, Ctr Biomed, Dept Biochem, S-75123 Uppsala, Sweden. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Szoke, A (reprint author), Univ Uppsala, Ctr Biomed, Dept Biochem, Box 576, S-75123 Uppsala, Sweden. NR 51 TC 7 Z9 7 U1 1 U2 6 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD SEP PY 2001 VL 57 BP 586 EP 603 DI 10.1107/S0108767301007322 PN 5 PG 18 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 468UT UT WOS:000170777100013 PM 11526308 ER PT J AU Gertsman, VY AF Gertsman, VY TI Geometrical theory of triple junctions of CSL boundaries. (vol A57, 369, 2001) SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Correction C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Gertsman, VY (reprint author), Pacific NW Natl Lab, POB 999,P8-16, Richland, WA 99352 USA. NR 1 TC 2 Z9 2 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD SEP PY 2001 VL 57 BP 627 EP 627 DI 10.1107/S0108767301010613 PN 5 PG 1 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 468UT UT WOS:000170777100016 ER PT J AU Kumaran, D Eswaramoorthy, S Furey, W Sax, M Swaminathan, S AF Kumaran, D Eswaramoorthy, S Furey, W Sax, M Swaminathan, S TI Structure of staphylococcal enterotoxin C2 at various pH levels SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID CRYSTAL-STRUCTURE; PROTEIN MODELS; BINDING-SITES; ZINC ENZYMES; T-CELLS; X-RAY; SUPERANTIGEN; TOXIN; REFINEMENT; CRYSTALLOGRAPHY AB The three-dimensional structure of staphylococcal enterotoxin C2 (SEC2), a toxin as well as a superantigen, has been determined at various pH levels from two different crystal forms, tetragonal (pH 5.0, 5.5, 6.0 and 6.5) and monoclinic (pH 8.0) at 100 and 293 K, respectively, by the molecular-replacement method. Tetragonal crystals belong to space group P4(3)2(1)2, with unit-cell parameters a = b = 42.68, c = 289.15 Angstrom (at pH 5.0), and monoclinic crystals to space group P2(1), with unit-cell parameters a = 43.3, b = 70.6, c = 42.2 Angstrom, beta = 90.3 degrees. SEC2 contains a zinc-binding motif, D+HExxH, and accordingly a Zn atom has been identified. The coordination of the zinc ion suggests that it may be catalytic zinc rather than structural, but there is so far no biological evidence that it possesses catalytic activity. However, superantigen staphylococcal exfoliative toxins A and B have been shown to have enzymatic activity after their fold was identified to be similar to that of serine protease. The structure and its conformation are similar to the previously reported structures of SEC2. Though it was expected that the zinc ion may be leached out, as the histidines coordinating the zinc ion are expected to be protonated below pH 6.0, zinc is present at all pH values. The coordination distances to zinc increase with decreasing pH, with the distances being the least at pH 8.0. The results of automated model building using the ARP/wARP program for different data sets collected at various pH values are discussed. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Vet Adm Med Ctr, Biocrystallog Lab, Pittsburgh, PA 15240 USA. Univ Pittsburgh, Dept Pharmacol, Pittsburgh, PA 15261 USA. RP Swaminathan, S (reprint author), Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. NR 42 TC 15 Z9 15 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD SEP PY 2001 VL 57 BP 1270 EP 1275 DI 10.1107/S0907444901011118 PN 9 PG 6 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 465VT UT WOS:000170611200007 PM 11526318 ER PT J AU Fronczek, FR Garcia, JG AF Fronczek, FR Garcia, JG TI (7-endo-Bromocamphorylsulfonyl)imine SO ACTA CRYSTALLOGRAPHICA SECTION E-STRUCTURE REPORTS ONLINE LA English DT Article AB [3aS-(3a alpha ,6 alpha ,7 beta)]-7-Bromo-4,5,6,7-tetrahydro-8,8-dimethyl-3H-3a,6-methano-2,1-benzisothiazole 2,2-dioxide, C10H14BrNO2S, has the (-)-camphorsulfonimine structure, with the Br atom beta -oriented. The C-Br distance is 1.941 (5) Angstrom, the S-N distance is 1.687 (3) Angstrom, and the C=N distance is 1.271 (6) Angstrom. C1 Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Fronczek, FR (reprint author), Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. NR 12 TC 1 Z9 1 U1 0 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 1600-5368 J9 ACTA CRYSTALLOGR E JI Acta Crystallogr. Sect. E.-Struct Rep. Online PD SEP PY 2001 VL 57 BP o886 EP o887 DI 10.1107/S1600536801013824 PN 9 PG 2 WC Crystallography SC Crystallography GA 480FQ UT WOS:000171451700043 ER PT J AU Nazarewicz, W Dobaczewski, J Matev, M Mizutori, S Satula, W AF Nazarewicz, W Dobaczewski, J Matev, M Mizutori, S Satula, W TI Rotational properties of neutron drip-line nuclei SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 2001 NATO Advanced Research Workshop of the High Spin Physics CY FEB 06-10, 2001 CL WARSAW, POLAND ID GROUND-STATE PROPERTIES; WEAKLY-BOUND NUCLEI; RICH RU ISOTOPES; SHAPE COEXISTENCE; MEAN-FIELD; QUADRUPOLE-MOMENTS; COULOMB-EXCITATION; BANDS; REGION; DEFORMATION AB We know very little about the structure of neutron-rich, weakly bound nuclei. We know even less about the way they rotate. In this work, the high-spin behavior of deformed neutron-rich nuclei is studied. In particular, quasi-particle Routhian spectra of heavy Er isotopes are discussed within the deformed shell model, and rotational properties and isovector shape deformations of heavy Ne and Mg isotopes are studied with the self-consistent cranked Skyrme-Hartree-Fock theory. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Warsaw, Inst Theoret Phys, PL-00681 Warsaw, Poland. Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. RP Nazarewicz, W (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. NR 57 TC 4 Z9 5 U1 0 U2 1 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD SEP PY 2001 VL 32 IS 9 BP 2349 EP 2364 PG 16 WC Physics, Multidisciplinary SC Physics GA 482GH UT WOS:000171568000010 ER PT J AU Svensson, CE Macchiavelli, AO Juodagalvis, A Poves, A Ragnarsson, I Aberg, S Appelbe, DE Austin, RAE Baktash, C Ball, GC Carpenter, MP Caurier, E Clark, RM Cromaz, M Deleplanque, MA Diamond, RM Fallon, P Furlotti, M Galindo-Uribarri, A Janssens, RVF Lane, GJ Lee, IY Lipoglavsek, M Nowacki, F Paul, SD Radford, DC Sarantites, DG Seweryniak, D Stephens, FS Tomov, V Vetter, K Ward, D Yu, CH AF Svensson, CE Macchiavelli, AO Juodagalvis, A Poves, A Ragnarsson, I Aberg, S Appelbe, DE Austin, RAE Baktash, C Ball, GC Carpenter, MP Caurier, E Clark, RM Cromaz, M Deleplanque, MA Diamond, RM Fallon, P Furlotti, M Galindo-Uribarri, A Janssens, RVF Lane, GJ Lee, IY Lipoglavsek, M Nowacki, F Paul, SD Radford, DC Sarantites, DG Seweryniak, D Stephens, FS Tomov, V Vetter, K Ward, D Yu, CH TI Fast rotation of the N = Z nucleus Ar-36 SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 2001 NATO Advanced Research Workshop on High Spin Physics CY FEB 06-10, 2001 CL WARSAW UNIV, INST THEORET PHYS, WARSAW, POLAND SP N Atlantic Treaty Org, Polish State Comm Sci Res (KBN), Leopold Kronenberg Fdn, Warsaw Univ, Polish Phys Soc, Polish Acad Sci, Comm Phys, Natl Atom Energy Agcy HO WARSAW UNIV, INST THEORET PHYS ID SHELL-MODEL DESCRIPTION; RESPONSE CHARACTERISTICS; CHANNEL-SELECTION; HIGH-SPIN; GAMMASPHERE; BANDS; MECHANISM AB A highly-deformed rotational band has been identified in the N = Z nucleus Ar-36. At high spin the band is observed to its presumed termination at I-pi = 16(+), while at low spin it has been firmly linked to previously known states in Ar-36. Spins, parities, and absolute excitation energies have thus been determined throughout the band. Lifetime measurements establish a large low-spin quadrupole deformation (beta (2) = 0.46 +/- 0.03) and indicate a decreasing collectivity as the band termination is approached. With effectively complete spectroscopic information and a valence space large enough for significant collectivity to develop, yet small enough to be meaningfully approached from the shell model perspective, this rotational band in Ar-36 provides many exciting opportunities to test and compare complementary models of collective motion in nuclei. C1 Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Lund Univ, Dept Math Phys, Lund, Sweden. Univ Madrid, Dept Fis Teor, Madrid 3, Spain. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. TRIUMF, Vancouver, BC V6T 2A3, Canada. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Strasbourg, Inst Rech Subatom, Strasbourg, France. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Univ Strasbourg, Phys Theor Lab, Strasbourg, France. RP Univ Guelph, Dept Phys, Guelph, ON N1G 2W1, Canada. RI Poves, Alfredo/L-2594-2013; radford, David/A-3928-2015; Carpenter, Michael/E-4287-2015 OI Poves, Alfredo/0000-0001-7539-388X; Carpenter, Michael/0000-0002-3237-5734 NR 19 TC 6 Z9 6 U1 0 U2 0 PU JAGIELLONIAN UNIV PRESS PI KRAKOW PA UL MICHALOWSKIEGO 9-2, KRAKOW, 31126, POLAND SN 0587-4254 EI 1509-5770 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD SEP PY 2001 VL 32 IS 9 BP 2413 EP 2422 PG 10 WC Physics, Multidisciplinary SC Physics GA 482GH UT WOS:000171568000016 ER PT J AU Maj, A Kmiecik, M Krolas, W Styczen, J Bracco, A Camera, F Million, B Gaardhoje, JJ Herskind, B Kicinska-Habior, M Kownacki, J Ormand, WE AF Maj, A Kmiecik, M Krolas, W Styczen, J Bracco, A Camera, F Million, B Gaardhoje, JJ Herskind, B Kicinska-Habior, M Kownacki, J Ormand, WE TI Search for the Jacobi instability in rapidly rotating Ti-46 nuclei SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 2001 NATO Advanced Research Workshop of the High Spin Physics CY FEB 06-10, 2001 CL WARSAW, POLAND ID HIGH-EXCITATION ENERGY AB The possible existence of Jacobi shape transition in hot Ti-46 at high angular momenta was investigated with the Giant Dipole Resonance exclusive experiments. The GDR spectra and the angular distributions are consistent with predictions of the thermal shape fluctuation model indicating elongated nuclear shapes. C1 H Niewodniczanski Inst Nucl Phys, PL-31342 Krakow, Poland. Univ Milan, Milan, Italy. Ist Nazl Fis Nucl, I-20133 Milan, Italy. Niels Bohr Inst, DK-2100 Copenhagen, Denmark. Warsaw Univ, Warsaw, Poland. Lawrence Livermore Natl Lab, Livermore, CA USA. RP Maj, A (reprint author), H Niewodniczanski Inst Nucl Phys, PL-31342 Krakow, Poland. RI Krolas, Wojciech/N-9391-2013 NR 12 TC 4 Z9 4 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD SEP PY 2001 VL 32 IS 9 BP 2433 EP 2439 PG 7 WC Physics, Multidisciplinary SC Physics GA 482GH UT WOS:000171568000018 ER PT J AU Ring, P Afanasjev, AV AF Ring, P Afanasjev, AV TI Effective field theory for rotational bands in deformed and superdeformed nuclei SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 2001 NATO Advanced Research Workshop of the High Spin Physics CY FEB 06-10, 2001 CL WARSAW, POLAND ID HARTREE-BOGOLIUBOV THEORY; RELATIVISTIC DESCRIPTION; A-SIMILAR-TO-190 REGION; IDENTICAL BANDS; MASS REGION AB An overview is given on the description of rotational bands in normally deformed and superdeformed nuclei in the framework of effective field theories such as the Relativistic Mean Field (RMF) theory and the Relativistic Hartree-Bogoliubov (RHB) theory. In particular we discuss recent investigations for the description of superdeformed bands in the A similar to 60, 140-150 and 190 mass regions and compare them briefly with the results obtained in non-relativistic mean field theories. C1 Tech Univ Munich, Dept Phys, D-85748 Garching, Germany. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Ring, P (reprint author), Tech Univ Munich, Dept Phys, D-85748 Garching, Germany. RI Ring, Peter/O-1638-2015 NR 18 TC 1 Z9 1 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD SEP PY 2001 VL 32 IS 9 BP 2469 EP 2478 PG 10 WC Physics, Multidisciplinary SC Physics GA 482GH UT WOS:000171568000021 ER PT J AU Lee, IY Clark, RM Ward, D Cromaz, M Deleplanque, MA Diamond, RM Fallon, P Gorgen, A Lane, GJ Macchiavelli, AO Stephens, FS Svensson, CE Vetter, K AF Lee, IY Clark, RM Ward, D Cromaz, M Deleplanque, MA Diamond, RM Fallon, P Gorgen, A Lane, GJ Macchiavelli, AO Stephens, FS Svensson, CE Vetter, K TI Recent results from Gammasphere SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 2001 NATO Advanced Research Workshop of the High Spin Physics CY FEB 06-10, 2001 CL WARSAW, POLAND AB Three examples of recent nuclear structure studies using Gammasphere axe discussed in this paper. (1) A rotational band has been identified in Cd-108. Its moment of inertia and quadrupole moment indicate that this band has a shape with an axis ratio larger than 1.8:1. (2) Possible "Jacobi" shape transitions at high spin were investigated from studies of the continuum gamma rays on a number of nuclei. (3) Population of high-spin states in neutron-rich nuclei were studied in target fragmentation reactions. States with spin up to 6-12h were observed in a wide range of nuclei. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Lee, IY (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. OI Gorgen, Andreas/0000-0003-1916-9941 NR 6 TC 3 Z9 3 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD SEP PY 2001 VL 32 IS 9 BP 2499 EP 2505 PG 7 WC Physics, Multidisciplinary SC Physics GA 482GH UT WOS:000171568000025 ER PT J AU Amzal, N Butler, PA Greenlees, PT Herzberg, RD Humphreys, RD Kankaanpaa, H Bastin, J Becker, F Brew, PM Cocks, JFC Cunningham, RA Czosnyka, T Eskola, K Gerl, J Hammond, NJ Hauschild, K Heikinen, P Helariutta, K Hessberger, FP Hurstel, A Iwanicki, I Jones, GD Jones, PM Julin, R Juutinen, S Keenan, A Kettunen, H Khlebnikov, S Khoo, TL Korten, W Kuusiniemi, P LeCoz, Y Leino, M Muikku, M Nieminen, P Page, T Rahkila, P Reiter, P Scholey, CS Sletten, G Stezowski, O Theisen, C Uusitalo, J Wollersheim, HJ AF Amzal, N Butler, PA Greenlees, PT Herzberg, RD Humphreys, RD Kankaanpaa, H Bastin, J Becker, F Brew, PM Cocks, JFC Cunningham, RA Czosnyka, T Eskola, K Gerl, J Hammond, NJ Hauschild, K Heikinen, P Helariutta, K Hessberger, FP Hurstel, A Iwanicki, I Jones, GD Jones, PM Julin, R Juutinen, S Keenan, A Kettunen, H Khlebnikov, S Khoo, TL Korten, W Kuusiniemi, P LeCoz, Y Leino, M Muikku, M Nieminen, P Page, T Rahkila, P Reiter, P Scholey, CS Sletten, G Stezowski, O Theisen, C Uusitalo, J Wollersheim, HJ TI The structure of heavy octupole and superheavy quadrupole deformed nuclei SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 2001 NATO Advanced Research Workshop of the High Spin Physics CY FEB 06-10, 2001 CL WARSAW, POLAND ID MOMENTS; NO-254 AB We report here experimental attempts to determine the sign of the electric dipole moment (relative to the electric octupole moment) in the octupole deformed nucleus Ra-226. Sensitivity to this quantity is observed in the measured yields of gamma -ray transitions following very low energy Coulomb excitation. Recent progress is also reported in the development of new spectroscopic techniques that promise to elucidate the structure of deformed superheavy nuclei in the region of No-254. The 4(+) --> 2(+) transition in No-254. as well as higher spin transitions, has been identified using recoil-tagged conversion electron spectroscopy. C1 Univ Liverpool, Oliver Lodge Lab, Liverpool L69 3BX, Merseyside, England. Univ Jyvaskyla, Dept Phys, Jyvaskyla, Finland. Univ Warsaw, Heavy Ion Lab, PL-00325 Warsaw, Poland. Daresbury Lab, Warrington, Cheshire, England. CEA Saclay, DAPNIA, SPHN, F-91191 Gif Sur Yvette, France. GSI Darmstadt, D-6100 Darmstadt, Germany. Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland. Univ Munich, Munich, Germany. Argonne Natl Lab, Argonne, IL 60439 USA. VG Khlopin Radium Inst, St Petersburg 197022, Russia. Niels Bohr Inst, DK-2100 Copenhagen, Denmark. RP Amzal, N (reprint author), Univ Liverpool, Oliver Lodge Lab, Liverpool L69 3BX, Merseyside, England. RI Hauschild, Karl/A-6726-2009; Herzberg, Rolf-Dietmar/E-1558-2011; KORTEN, Wolfram/H-3043-2013; Scholey, Catherine/G-2720-2014; THEISEN, Christophe/A-9343-2015; OI Scholey, Catherine/0000-0002-8743-6071; THEISEN, Christophe/0000-0002-8509-1022; KORTEN, Wolfram/0000-0002-3940-0816; Hammond, Neil/0000-0001-6390-8874; Butler, Peter/0000-0001-6080-9205 NR 16 TC 2 Z9 2 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD SEP PY 2001 VL 32 IS 9 BP 2519 EP 2526 PG 8 WC Physics, Multidisciplinary SC Physics GA 482GH UT WOS:000171568000027 ER PT J AU Riedinger, LL Hartley, DJ Galindo-Uribarri, A Smith, BH Baktash, C Carpenter, MP Danchev, M Devlin, M Gross, CJ Janssens, RVF Lipoglavsek, M Paul, SD Radford, DC Reviol, W Sarantites, DG Seweryniak, D Yu, CH Zeidan, O AF Riedinger, LL Hartley, DJ Galindo-Uribarri, A Smith, BH Baktash, C Carpenter, MP Danchev, M Devlin, M Gross, CJ Janssens, RVF Lipoglavsek, M Paul, SD Radford, DC Reviol, W Sarantites, DG Seweryniak, D Yu, CH Zeidan, O TI Signature inversion in odd-odd nuclei SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 2001 NATO Advanced Research Workshop of the High Spin Physics CY FEB 06-10, 2001 CL WARSAW, POLAND ID RARE-EARTH NUCLEI; RESIDUAL INTERACTION; TRIAXIALITY; STATES AB Trends in the energy staggering of the pih(11)/(2)nui(13/2) and pih(11)/(2)nuh(11/2) bands in the mass 160 and 130 regions, respectively, have been investigated in order to better understand the origin of signature inversion. While the A approximate to 160 nuclei behave in a consistent manner, a more complicated scenario is observed in the mass 130 region. As a result of our experiments on the lightest Pr nuclei, the systematics of these Z = 59 nuclei have been extended, which aids in the understanding of the latter region. Triaxial deformation, a pn interaction, and quadrupole pairing are considered as possible contributors to this effect. As all the chiral-twin bands that are known have signature inversion in the favored band, a possible link between the two phenomena should be considered. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Riedinger, LL (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RI radford, David/A-3928-2015; Carpenter, Michael/E-4287-2015; Devlin, Matthew/B-5089-2013 OI Carpenter, Michael/0000-0002-3237-5734; Devlin, Matthew/0000-0002-6948-2154 NR 18 TC 14 Z9 14 U1 0 U2 1 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD SEP PY 2001 VL 32 IS 9 BP 2613 EP 2623 PG 11 WC Physics, Multidisciplinary SC Physics GA 482GH UT WOS:000171568000036 ER PT J AU Riley, MA Laird, RW Kondev, FG Hartley, DJ Archer, DE Brown, TB Clark, RM Devlin, M Fallon, P Hibbert, IM Joss, DT LaFosse, DR Nolan, PJ O'Brien, NJ Paul, ES Pfohl, J Sarantites, DG Sheline, RK Shepherd, SL Simpson, J Wadsworth, R Matev, MT Afanasjev, AV Dobaczewski, J Lalazissis, GA Nazarewicz, W Satula, W AF Riley, MA Laird, RW Kondev, FG Hartley, DJ Archer, DE Brown, TB Clark, RM Devlin, M Fallon, P Hibbert, IM Joss, DT LaFosse, DR Nolan, PJ O'Brien, NJ Paul, ES Pfohl, J Sarantites, DG Sheline, RK Shepherd, SL Simpson, J Wadsworth, R Matev, MT Afanasjev, AV Dobaczewski, J Lalazissis, GA Nazarewicz, W Satula, W TI Global lifetime measurements of highly-deformed and other rotational structures in the A similar to 135 light rare-earth region: Probing the single-particle motion in a rotating potential SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT 2001 NATO Advanced Research Workshop of the High Spin Physics CY FEB 06-10, 2001 CL WARSAW, POLAND ID RELATIVE QUADRUPOLE DEFORMATIONS; ODD-ODD PR-130; SUPERDEFORMED BANDS; MASS REGION; IDENTICAL BANDS; NUCLEI; MOMENTS; ADDITIVITY; TRANSITION; DY-152 AB It has been possible, using Gammasphere plus Microball, to extract differential lifetime measurements free from common systematic errors for over 15 different nuclei (various isotopes of Ce, Pr, Nd, Pm, and Sm) at high spin within a single experiment. This comprehensive study establishes the effective single-particle quadrupole moments in the A similar to 135 light rare-earth region. Detailed comparisons axe made with calculations using the self-consistent cranked mean-field theory. C1 Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Univ Calif Berkeley, Div Nucl Sci, Berkeley, CA 94720 USA. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Univ York, Dept Phys, York Y01 5DD, N Yorkshire, England. Univ Liverpool, Oliver Lodge Lab, Liverpool L69 3BX, Merseyside, England. SERC, Daresbury Lab, CLRC, Warrington WA4 4AD, Cheshire, England. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Tech Univ Munich, Dept Phys, D-85747 Garching, Germany. Univ Warsaw, Inst Theoret Phys, PL-00681 Warsaw, Poland. Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Aristotelian Univ Thessaloniki, Dept Theoret Phys, GR-54006 Thessaloniki, Greece. Latvian State Univ, Lab Radiat Phys, Inst Solid State Phys, LV-2169 Salaspils, Latvia. RP Riley, MA (reprint author), Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. RI Devlin, Matthew/B-5089-2013; Paul, Stephan/F-7596-2015 OI Devlin, Matthew/0000-0002-6948-2154; Paul, Stephan/0000-0002-8813-0437 NR 46 TC 11 Z9 11 U1 0 U2 1 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD SEP PY 2001 VL 32 IS 9 BP 2683 EP 2695 PG 13 WC Physics, Multidisciplinary SC Physics GA 482GH UT WOS:000171568000043 ER PT J AU Weber, RJ Orsini, D Daun, Y Lee, YN Klotz, PJ Brechtel, F AF Weber, RJ Orsini, D Daun, Y Lee, YN Klotz, PJ Brechtel, F TI A particle-into-liquid collector for rapid measurement of aerosol bulk chemical composition SO AEROSOL SCIENCE AND TECHNOLOGY LA English DT Article ID FLIGHT MASS-SPECTROMETRY; AUTOMATED MEASUREMENT; SIZE; IMPACTOR; NITRATE; SYSTEM AB We report on a new instrument developed for rapid automated on-line and continuous measurement of ambient aerosol bulk composition. The general approach is based on earlier devices (Khlystov et al. 1995; Simon and Dasgupta 1995) in which ambient particles are mixed with saturated water vapor to produce droplets easily collected by inertial techniques. The resulting liquid stream is an ah-zed with an ion chromatograph to quantitatively measure the bulk aerosol ionic components. In this instrument, a modified version of a particle size magnifier (Okuyama et al. 1984) is employed to activate and grow particles comprising the fine aerosol mass. A single jet inertial impactor is used to collect the droplets onto a vertical glass plate that is continually washed with a constant water diluent flow of nominally 0.10 ml min(-1). The flow is divided and then analyzed by a dual channel ion chromatograph. In its current form, 4.3 min integrated samples were measured every 7 min. The instrument provides bulk composition measurements with a detection limit of approximately 0.1 mug m(-3) for chloride, nitrate, sulfate, sodium, ammonium, calcium, and potassium. Results obtained during its deployment in the August 1999 Atlanta EPA Supersite study are presented. C1 Georgia Inst Technol, Dept Earth & Atmospher Sci, Atlanta, GA 30332 USA. Brookhaven Natl Lab, Dept Environm Sci, New York, NY USA. RP Weber, RJ (reprint author), Georgia Inst Technol, Dept Earth & Atmospher Sci, 221 Bobby Dodd Way, Atlanta, GA 30332 USA. NR 26 TC 264 Z9 275 U1 5 U2 54 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA SN 0278-6826 J9 AEROSOL SCI TECH JI Aerosol Sci. Technol. PD SEP PY 2001 VL 35 IS 3 BP 718 EP 727 DI 10.1080/02786820152546761 PG 10 WC Engineering, Chemical; Engineering, Mechanical; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 473BT UT WOS:000171020000003 ER PT J AU Sheehan, JS Himmel, ME AF Sheehan, JS Himmel, ME TI Outlook for bioethanol production from lignocellulosic feedstocks: Technology hurtles SO AGRO FOOD INDUSTRY HI-TECH LA English DT Article ID TRICHODERMA-REESEI; HYDROLYSIS; EVOLUTION; CELLULOSE; CELLOBIOHYDROLASES; MODEL; OIL AB Ethanol is used today as an alternative fuel, a fuel extender, an oxygenate, and an octane enhancer From just over 10 million gallons of production in 1979, the U.S. fuel ethanol industry has grown to more than 1.8 billion gallons of annual production capacity, These commercial operations use technology that converts corn starch to sugars, which are then fermented to ethanol. Throughout this time, the U. S. Department of Energy has invested in R&D technology that will allow the fuel ethanol industry to expand production using lignocellulosic feedstocks. However unlike starch, cellulose is highly resistant to enzymatic degradation. It is now clear that cutting-edge biochemical technologies must be used to reduce the cost of cellulase activity delivered to the bioethanol process. We estimate that cellulase usage would contribute around $0.60 to the cost of making one gallon of ethanol using currently available technology. These costs must be reduced ten-fold by 2015. Technically, this objective requires a ten-fold increase in enzyme specific activity or production efficiency or some combination thereof. C1 Natl Ctr Bioenergy Res, Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 25 TC 7 Z9 7 U1 1 U2 1 PU TEKNOSCIENZE PUBL PI MILAN PA VIA AURELIO SAFFI 23, 20123 MILAN, ITALY SN 1120-6012 J9 AGRO FOOD IND HI TEC JI Agro Food Ind. Hi-Tech PD SEP-OCT PY 2001 VL 12 IS 5 BP 54 EP 57 PG 4 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA 495MX UT WOS:000172345900012 ER PT J AU Cohen, HJ Hecker, LH Mattheis, DK Johnson, JS Biermann, AH Foote, KL AF Cohen, HJ Hecker, LH Mattheis, DK Johnson, JS Biermann, AH Foote, KL TI Simulated workplace protection factor study of powered air purifying and supplied air respirators SO AIHAJ LA English DT Article DE protection factor; respirator ID LEAD AB A study protocol was developed to obtain simulated workplace protection factor (SWPF) data for eleven models of powered air-purifying respirators (PAPRs) and supplied-air respirators (SAR) with hoods and helmets. Respirators were tested in a chamber that allowed the simulation of 12 exercises, Including 2 exercises of interest to the pharmaceutical industry. Each respirator was tested by 12 volunteers, and a total of 144 sets of test results were obtained for each device. The testing protocol allowed SWPFs up to 250,000 to be measured (limit of quantification). Median SWPFs for all respirators, except one SAR, were at or above this reporting limit. Lower fifth percentiles were above 100,000, except for one SAR previously noted. An assigned protection factor (APF) was estimated for each respirator by dividing the lower fifth percentile by a safety factor of 25. APFs ranged from 6000-10,000 for PAPRs (Including one loose-fitting PAPR) and 3400-10,000 for SARs, with one exception. This SAR had a lower fifth percentile of less than 20 and an estimated APF of 1. Results indicated that most respirators tested could provide a high degree of protection for workers, although one National Institute for Occupational Safety and Health-approved SAR provided minimal, if any, protection, Direct testing in a simulated workplace seems the only method that will assure employers of choosing an adequate SAR, This may be true for other classes of respirators. Furthermore, the historical approach of establishing APFs for classes of respirators, rather than individual models, may not provide adequate protection to the wearer. This is also a serious problem for regulatory agencies seeking to promulgate respirator standard provisions such as APFs for classes of respirators. C1 Univ New Haven, Dept Occupat Safety & Hlth, W Haven, CT 06516 USA. Abbott Labs, Abbott Pk, IL 60064 USA. Org Resources Counselors, Washington, DC USA. Lawrence Livermore Natl Lab, Livermore, CA USA. RP Cohen, HJ (reprint author), Univ New Haven, Dept Occupat Safety & Hlth, 300 Orange Ave, W Haven, CT 06516 USA. NR 24 TC 13 Z9 13 U1 0 U2 2 PU AMER INDUSTRIAL HYGIENE ASSOC PI FAIRFAX PA 2700 PROSPERITY AVE #250, FAIRFAX, VA 22031-4307 USA SN 1529-8663 J9 AIHAJ JI AIHAJ PD SEP-OCT PY 2001 VL 62 IS 5 BP 595 EP 604 DI 10.1202/0002-8894(2001)062<0595:SWPFSO>2.0.CO;2 PG 10 WC Environmental Sciences; Public, Environmental & Occupational Health SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health GA 482VE UT WOS:000171597300006 PM 11669385 ER PT J AU Ravi, R Marathe, MV Ravi, SS Rosenkrantz, DJ Hunt, HB AF Ravi, R Marathe, MV Ravi, SS Rosenkrantz, DJ Hunt, HB TI Approximation algorithms for degree-constrained minimum-cost network-design problems SO ALGORITHMICA LA English DT Article DE approximation algorithms; network design; bicriteria problems ID DEGREE SPANNING-TREES; STEINER PROBLEM; WEIGHT; HEURISTICS AB We study network-design problems with two different design objectives: the total cost of the edges and nodes in the network and the maximum degree of any node in the network. A prototypical example is the degree-constrained node-weighted Steiner tree problem: We are given an undirected graph G(V, E), with a nonnegative integral function d that specifies an upper bound d(v) on the degree of each vertex v is an element of V in the Steiner tree to be constructed, nonnegative costs on the nodes, and a subset of k nodes called terminals. The goal is to construct a Steiner tree T containing all the terminals such that the degree of any node v in T is at most the specified upper bound d(v) and the total cost of the nodes in T is minimum. Our main result is a bicriteria approximation algorithm whose output is approximate in terms of both the degree and cost criteria-the degree of any node v is an element of V in the output Steiner tree is O(d(v)log k) and the cost of the tree is 0(log k) times that of a minimum-cost Steiner tree that obeys the degree bound d(v) for each node v. Our result extends to the more general problem of constructing one-connected networks such as generalized Steiner forests. We also consider the special case in which the edge costs obey the triangle inequality and present simple approximation algorithms with better performance guarantees. C1 Carnegie Mellon Univ, Grad Sch Ind Adm, Pittsburgh, PA 15213 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. SUNY Albany, Dept Comp Sci, Albany, NY 12222 USA. RP Ravi, R (reprint author), Carnegie Mellon Univ, Grad Sch Ind Adm, Pittsburgh, PA 15213 USA. NR 28 TC 57 Z9 57 U1 0 U2 2 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0178-4617 J9 ALGORITHMICA JI Algorithmica PD SEP PY 2001 VL 31 IS 1 BP 58 EP 78 DI 10.1007/s00453-001-0038-2 PG 21 WC Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 446ZJ UT WOS:000169543800004 ER PT J AU Schultz, PA Miller, RM Jastrow, JD Rivetta, CV Bever, JD AF Schultz, PA Miller, RM Jastrow, JD Rivetta, CV Bever, JD TI Evidence of a mycorrhizal mechanism for the adaptation of Andropogon gerardii (Poaceae) to high- and low-nutrient prairies SO AMERICAN JOURNAL OF BOTANY LA English DT Article DE adaptations; Andropogon gerardii; mycorrhizae; Poaceae; prairie; soil phosphorus ID TALLGRASS PRAIRIE; WHEAT CULTIVARS; DEPENDENCE; FUNGI; COLONIZATION; GRASSLAND; GROWTH; PLANTS; SPORULATION; COMMUNITIES AB Andropogon gerardii seed obtained from Kansas and Illinois was grown in a controlled environment in their own and each other's soils, with and without arbuscular mycorrhizal fungi (AMF). Each ecotype grew comparatively better in its own soil indicating adaptation to its soil of origin. Overall, A. gerardii benefited more from AMF in low-nutrient Kansas soil than Illinois soil. The two ecotypes, however, did not benefit equally from mycorrhizal infection. The Kansas ecotype was three times more responsive to mycorrhizal infection in the Kansas soil than was the Illinois ecotype. Our results indicate that plant adaptation to the nutrient levels of their local soils is likely to be due, at least in part, to a shift in their dependence on mycorrhizal fungi. The Illinois ecotype of A. gerardii has evolved a reduced dependence upon these fungi and greater reliance on a more highly branched root system. In contrast, the Kansas ecotype had a significantly coarser root system and invested proportionately greater carbon in the symbiotic association with AMF as measured by spore production. This study provides the first demonstration that plants can adapt to changing soil nutrient levels by shifting their dependence on AMF. This result has broad implications for our understanding of the role of these fungi in agricultural systems. C1 Indiana Univ, Dept Biol, Bloomington, IN 47405 USA. Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Schultz, PA (reprint author), Indiana Univ, Dept Biol, Jordan Hall,1001 E 3rd St, Bloomington, IN 47405 USA. NR 37 TC 65 Z9 69 U1 2 U2 39 PU BOTANICAL SOC AMER INC PI COLUMBUS PA OHIO STATE UNIV-DEPT BOTANY, 1735 NEIL AVE, COLUMBUS, OH 43210 USA SN 0002-9122 J9 AM J BOT JI Am. J. Bot. PD SEP PY 2001 VL 88 IS 9 BP 1650 EP 1656 DI 10.2307/3558410 PG 7 WC Plant Sciences SC Plant Sciences GA 473VP UT WOS:000171069600015 PM 21669699 ER PT J AU Friedrich, A Lager, GA Kunz, M Chakoumakos, BC Smyth, JR Schultz, AJ AF Friedrich, A Lager, GA Kunz, M Chakoumakos, BC Smyth, JR Schultz, AJ TI Temperature-dependent single-crystal neutron diffraction study of natural chondrodite and clinohumites SO AMERICAN MINERALOGIST LA English DT Article ID HYDROUS MAGNESIUM SILICATES; EARTHS UPPER-MANTLE; HUMITE MINERALS; SYSTEM MGO-SIO2-H2O; WATER; SPECTRA; STABILITY; CHEMISTRY; PRESSURES AB The crystal structures of natural F-bearing chondrodite [Mg4.64Fe0.28Mn0.014Ti0.023(Si1.01O4)(2) F1.02OH0.97] from the Tilley Foster mine (Brewster, New York), F-bearing titanian clinohumite [Mg8.805Fe0.006Ti0.214(Si0.993O4)(4)F0.484OH0.516] from Kukh-i-Lal (Tadjikistan) and F-free titanian hydroxy[clinohumite [Mg7.378Fe1.12Mn0.052Ni0.014Ti0.453(Si0.996O4)(4)OH1.0] from Val Malenco (Italy) were refined in space group P2(1)/b (unique axis a) from single-crystal neutron diffraction data, collected on a four-circle diffractometer at the High Flux Isotope Reactor at Oak Ridge National Laboratory. Accurate H atom positions were determined at 295 K, 100 K, and 20 (10) K. Only one H position of approximately 50% occupancy was observed for each structure, which confirms a disordered H model. Time-of-flight single-crystal neutron data were also collected at 295 K and 20 K for the Val Malenco clinohumite as an additional check on space group symmetry. The crystal structure of the Kukh-i-Lal clinohumite was further investigated by X-ray single-crystal refinement at 295 K and by piezoelectric measurements. A few, very weak, symmetry-forbidden reflections were observed for each crystal at both ambient and lower temperatures. The same reflections were observed by all methods used. No temperature dependence is indicated, as no additional peaks appear at low temperature, and the intensity of the reflections are sample dependent. It appears that the real structure is made up of P2(1) and Pb domains so that violations are due to ordering of both H and Ti. No distinct piezoelectric effect was observed that would indicate the absence of a center of symmetry. This points to the simultaneous presence of various enantiomorphic domains, which cancels the piezoelectric effect of individual domains. The decrease in unit-cell volume with F substitution in clinohumites can be explained by the higher concentration of H-site vacancies and the coupled cationic and anionic substitution on the M3 and O/F site. C1 ETH Zentrum, Lab Kristallograph, CH-8092 Zurich, Switzerland. Univ Louisville, Dept Geog & Geosci, Louisville, KY 40292 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Colorado, Dept Geol Sci, Boulder, CO 80309 USA. Argonne Natl Lab, Div Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP Friedrich, A (reprint author), ETH Zentrum, Lab Kristallograph, Sonneggstr 5, CH-8092 Zurich, Switzerland. RI Kunz, Martin/K-4491-2012; Chakoumakos, Bryan/A-5601-2016 OI Kunz, Martin/0000-0001-9769-9900; Chakoumakos, Bryan/0000-0002-7870-6543 NR 40 TC 17 Z9 18 U1 1 U2 3 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD SEP PY 2001 VL 86 IS 9 BP 981 EP 989 PG 9 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 472EB UT WOS:000170969600004 ER PT J AU Blencoe, JG Naney, MT Anovitz, LM AF Blencoe, JG Naney, MT Anovitz, LM TI The CO2-H2O system: III. A new experimental method for determining liquid-vapor equilibria at high subcritical temperatures SO AMERICAN MINERALOGIST LA English DT Article ID CARBON-DIOXIDE; FLUID INCLUSIONS; PRESSURES; MPA; EQUATION; MIXTURES; STATE; WATER AB A highly precise and accurate vibrating U-tube technique was developed to determine the upper baric stabilities of liquid-vapor assemblages in the CO2-H2O system at high subcritical temperatures (similar to 275-360 degreesC). The first step is to create an isobaric-isothermal, physically isolated and chemically homogeneous sample of "high-pressure" CO2-H2O fluid of known composition. Fluid pressure (P) is then lowered slowly at constant temperature. Pressure readings and matching values for tau (the period of vibration of the U-tube) are recorded at 0.1 or 0.2 MPa intervals. When the fluid begins to separate into two phases (liquid + vapor), a distinct inflection is observed in the trend of P vs. tau. Performing such experiments for fluid compositions at 0.05 mole fraction CO2 (X-CO2) intervals in the range 0.05 less than or equal to X-CO2 less than or equal to 0.40 at 300 degreesC produced a complete high-P liquid-vapor boundary curve for the CO2-H2O system at that temperature. Agreement with corresponding curves determined in previous studies ranges from poor to excellent. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Blencoe, JG (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008,Bldg 4500-S, Oak Ridge, TN 37831 USA. RI Anovitz, Lawrence/P-3144-2016 OI Anovitz, Lawrence/0000-0002-2609-8750 NR 16 TC 27 Z9 27 U1 2 U2 12 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD SEP PY 2001 VL 86 IS 9 BP 1100 EP 1111 PG 12 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 472EB UT WOS:000170969600018 ER PT J AU Lin, YM Raffen, R Zhou, YS Cassidy, CS Flavin, MT Stevens, FJ AF Lin, YM Raffen, R Zhou, YS Cassidy, CS Flavin, MT Stevens, FJ TI Amyloid fibril formation in microwell plates for screening of inhibitors SO AMYLOID-JOURNAL OF PROTEIN FOLDING DISORDERS LA English DT Article DE fibril formation; microwell plate assay; LEN V-L inhibitor ID IMMUNOGLOBULIN DEPOSITION DISEASE; THIOFLAVINE-T INTERACTION; LIGHT-CHAIN DEPOSITION; CENTRAL-NERVOUS-SYSTEM; ALZHEIMERS-DISEASE; FANCONIS SYNDROME; IN-VITRO; BETA; PROTEIN; PEPTIDE AB Fibril formation is the basis of amyloid production in a number of disease states, such as Alzheimer's disease, diabetes and immunocytic dyscrasias. Compounds that inhibit fibril formation could be directly relevant to the treatment of amyloid diseases, and may also provide a foundation for the development of interventions in other molecular condensation diseases ranging from sickle cell anemia to atherosclerosis. We developed an economical and convenient high-throughput method for screening compounds against fibril formation in microwell plates. Chalcones, flavonoids and biflavonoids were screened against fibril formation by a recombinant antibody variable domain (V-L). Chalcones 6 and 14 were found to demonstrate inhibition at 0.1 PM in 79 muM of protein solution in both test tube and microwell plate assays. The concentration of protein in the microwell plate assay could be as low as 5 muM using ThT as a monitoring agent. Molecular modeling studies indicated that both compounds could be individually docked into a binding site at the monomer-monomer interface of the V-L protein dimer. These studies suggested that these compounds could potentially stabilize the VL dimer and therefore reduce its tendency to form fibrils. These findings may provide the basis for a new therapeutic approach to prevent or treat amyloid diseases. C1 MediChem Life Sci Inc, Woodridge, IL 60517 USA. Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. RP Lin, YM (reprint author), MediChem Life Sci Inc, 2501 Davey Rd, Woodridge, IL 60517 USA. FU NIDDK NIH HHS [DK43757] NR 66 TC 11 Z9 11 U1 1 U2 2 PU PARTHENON PUBLISHING GROUP PI CARNFORTH LANCASHIRE PA CASTERTON HALL, CARNFORTH LANCASHIRE LA6 2LA, ENGLAND SN 1350-6129 J9 AMYLOID JI Amyloid-J. Protein Fold. Disord. PD SEP PY 2001 VL 8 IS 3 BP 182 EP 193 DI 10.3109/13506120109007361 PG 12 WC Biochemistry & Molecular Biology; Medicine, General & Internal; Medicine, Research & Experimental SC Biochemistry & Molecular Biology; General & Internal Medicine; Research & Experimental Medicine GA 479LM UT WOS:000171405900003 PM 11676295 ER PT J AU Egorov, OB O'Hara, MJ Farmer, OT Grate, JW AF Egorov, OB O'Hara, MJ Farmer, OT Grate, JW TI Extraction chromatographic separations and analysis of actinides using sequential injection techniques with on-line inductively coupled plasma mass spectrometry (ICP MS) detection SO ANALYST LA English DT Article ID FLOW-INJECTION; NUCLEAR WASTE; ION-CHROMATOGRAPHY; AUTOMATED-ANALYSIS; PRECONCENTRATION; URANIUM; SAMPLES; TC-99; SR-90 AB A sequential injection (SI) separation system has been developed for separation and analysis of Am, Pu, and Np isotopes using on-line inductively coupled plasma mass spectrometry (ICP MS) detection. On-line actinide separations were carried out using an actinide-specific extraction chromatographic material (TRU-resin, Eichrom Industries. Inc. USA). Separations are demonstrated and characterized that are compatible with on-line ICP MS detection and address isobaric ( Am-241/Pu-241, Pu-244/Cm-244. U-238/Pu-238), molecular ((UH)-U-238/Pu-239), and spectral (U-238/Np-237) interferences encountered in the analysis of Am. Pu and Np isotopic composition using ICP MS. The effects of reductive sample treatment on the extent of U matrix removal were investigated. Uranium separation factors were limited by the formation of U(iv) species, which exhibited separation behaviors similar to that of Pu(IV) and Np(iv). Nevertheless, separation factors as high as 3.0 x 10(5) can be achieved at the 0.1 mg ml(-1) U concentration levels using Fe(II) sulfamate as a reductant. The sequential injection (SI) ICP MS technique has been applied towards analysis of Am. Pu, and Np isotopes in a dissolved vitrified nuclear waste sample. Results obtained using the automated separation technique with ICP MS detection were in satisfactory agreement with results obtained using standard analytical methodologies. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Pacific NW Natl Lab, Appl Geol & Geochem Grp, Richland, WA 99352 USA. Pacific NW Natl Lab, Adv Inorgan Anal Grp, Richland, WA 99352 USA. RP Egorov, OB (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. RI O'Hara, Matthew/I-4967-2013; OI O'Hara, Matthew/0000-0003-3982-5897 NR 34 TC 45 Z9 46 U1 1 U2 12 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0003-2654 J9 ANALYST JI Analyst PD SEP PY 2001 VL 126 IS 9 BP 1594 EP 1601 DI 10.1039/b009842f PG 8 WC Chemistry, Analytical SC Chemistry GA 474WG UT WOS:000171129400020 ER PT J AU Kim, T Tang, KQ Udseth, HR Smith, RD AF Kim, T Tang, KQ Udseth, HR Smith, RD TI A multicapillary inlet jet disruption electrodynamic ion funnel interface for improved sensitivity using atmospheric pressure ion sources SO ANALYTICAL CHEMISTRY LA English DT Article ID IONIZATION MASS-SPECTROMETRY; ELECTROSPRAY-IONIZATION; TRANSMISSION; PRINCIPLES; MOBILITY; FIELD AB A new multicapillary inlet and ion funnel interface for electrospray ionization-mass spectrometry has been developed and demonstrated to achieve higher ion transmission efficiency compared to a single-capillary inlet and ion funnel interface. Even though the distance between the end of the ESI inlet capillary and the exit of the ion funnel (10 cm) is significantly longer than that of the conventional interface (typically a few millimeters), a significant part of the directed inlet gas flow persists into the first stage of pumping and results in an increased gas load to the second chamber. A jet disrupter made of a circular metal disk placed on axis in the ion funnel enhanced the dispersion of the directed gas flow from a multicapillary inlet and was also found to improve the ion transmission. The ion funnel with the jet disrupter demonstrated a 15% improvement in ion transmission (compared to that without the jet disrupter) and simultaneously reduced the pumping speed required for the first or second stage by a factor of 2-3. Compared to the sensitivity with the standard mass spectrometer interface (an API 3000, Sciex, Concord, ON, Canada) in MS/MS operation using an interface equipped with the jet disrupter and ion funnel, a 5.3-10.7-fold enhancement in signal was observed for samples with concentrations of 100-500 pg/muL and 10.2 to 14.1-fold enhancement for concentrations of 10 to 50 pg/muL. The decreased enhancement at higher concentrations is attributed to space charge effects and detector saturation. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Smith, RD (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NCRR NIH HHS [RR12365] NR 23 TC 61 Z9 63 U1 2 U2 36 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 2001 VL 73 IS 17 BP 4162 EP 4170 DI 10.1021/ac010174e PG 9 WC Chemistry, Analytical SC Chemistry GA 470FG UT WOS:000170859300026 PM 11569805 ER PT J AU Visser, H Curtright, AE McCusker, JK Sauer, K AF Visser, H Curtright, AE McCusker, JK Sauer, K TI Attenuated total reflection design for in situ FT-IR spectroelectrochemical studies SO ANALYTICAL CHEMISTRY LA English DT Article ID TRANSFORM INFRARED-SPECTROSCOPY; ELECTROCHEMICAL-CELL; VARIABLE-TEMPERATURE; ABSORPTION; ELECTRODE; INSITU; FERROCENE; SYSTEMS AB A versatile spectroelectrochemical apparatus is introduced to study the changes in IR spectra of organic and inorganic compounds upon oxidation or reduction. The design is based on an attenuated total reflection device, which permits the study of a wide spectral range of 16 700 (600 nm)-250 cm(-1),with a small opaque region of 2250-1900 cm(-1). In addition, an IR data collection protocol is introduced to deal with electrochemically nonreversible background signals. This method is tested with ferrocene in acetonitrile; concentrations as low as 1 mM produce results that agree with those in the literature. C1 Lawrence Berkeley Lab, Phys Biosci Div, Melvin Calvin Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Sauer, K (reprint author), Lawrence Berkeley Lab, Phys Biosci Div, Melvin Calvin Lab, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM 55302] NR 30 TC 9 Z9 9 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD SEP 1 PY 2001 VL 73 IS 17 BP 4374 EP 4378 DI 10.1021/ac010167q PG 5 WC Chemistry, Analytical SC Chemistry GA 470FG UT WOS:000170859300054 PM 11569833 ER PT J AU Hao, SG Ma, XP Yuan, SX Southon, J AF Hao, SG Ma, XP Yuan, SX Southon, J TI The Donghulin Woman from western Beijing: C-14 age and an associated compound shell necklace SO ANTIQUITY LA English DT Article C1 Beijing Univ, Dept Geol, Beijing 100871, Peoples R China. Beijing Univ, Dept Archaeol, Beijing 100871, Peoples R China. Lawrence Livermore Natl Lab, Ctr AMS, Livermore, CA 94551 USA. RP Hao, SG (reprint author), Beijing Univ, Dept Geol, Beijing 100871, Peoples R China. NR 22 TC 4 Z9 7 U1 1 U2 2 PU ANTIQUITY PUBL LTD PI CAMBRIDGE PA NEW HALL, CAMBRIDGE CB3 0DF, ENGLAND SN 0003-598X J9 ANTIQUITY JI Antiquity PD SEP PY 2001 VL 75 IS 289 BP 517 EP 522 PG 6 WC Anthropology; Archaeology SC Anthropology; Archaeology GA 470KY UT WOS:000170872200025 ER PT J AU de Souza, MP Amini, A Dojka, MA Pickering, IJ Dawson, SC Pace, NR Terry, N AF de Souza, MP Amini, A Dojka, MA Pickering, IJ Dawson, SC Pace, NR Terry, N TI Identification and characterization of bacteria in a selenium-contaminated hypersaline evaporation pond SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID SAN-JOAQUIN VALLEY; AGRICULTURAL DRAINAGE WATER; HALOPHILIC BACTERIA; CRYSTALLIZER PONDS; INDIAN MUSTARD; CALIFORNIA; VOLATILIZATION; COMMUNITY; DIVERSITY; REDUCTION AB Solar evaporation ponds are commonly used to reduce the volume of seleniferous agricultural drainage water in the San Joaquin Valley, Calif. These hypersaline ponds pose an environmental health hazard because they are heavily contaminated with selenium (Se), mainly in the form of selenate. Se in the ponds may be removed by microbial Se volatilization, a bioremediation process whereby toxic, bioavailable selenate is converted to relatively nontoxic dimethylselenide gas. In order to identify microbes that may be used for Se bioremediation, a 16S ribosomal DNA phylogenetic analysis of an aerobic hypersaline pond in the San Joaquin Valley showed that a previously unaffiliated group of uncultured bacteria (belonging to the order Cytophagales) was dominant, followed by a group of cultured gamma -Proteobacteria which was closely related to Halomonas species. Se K-edge X-ray absorption spectroscopy of selenate-treated bacterial isolates showed that they accumulated a mixture of predominantly selenate and a selenomethionine-like species, consistent with the idea that selenate was assimilated via the S assimilation pathway. One of these bacterial isolates (Halomonas-like strain MPD-51) was the best candidate for the bioremediation of hypersaline evaporation ponds contaminated with high Se concentrations because it tolerated 2 M selenate and 32.5% NaCl, grew rapidly in media containing selenate, and accumulated and volatilized Se at high rates (1.65 mug of Se g of protein(-1) h(-1)), compared to other cultured bacterial isolates. C1 Univ Calif Berkeley, Dept Plant & Microbial Biol, Berkeley, CA 94720 USA. Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Menlo Pk, CA 94025 USA. RP Terry, N (reprint author), Univ Calif Berkeley, Dept Plant & Microbial Biol, 111 Koshland Hall, Berkeley, CA 94720 USA. RI Pickering, Ingrid/A-4547-2013; OI Pickering, Ingrid/0000-0002-0936-2994 NR 38 TC 40 Z9 42 U1 0 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 SEP PY 2001 VL 67 IS 9 BP 3785 EP 3794 DI 10.1128/AEM.67.9.3785-3794.2001 PG 10 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 468FH UT WOS:000170747100003 PM 11525968 ER PT J AU Eschenfeldt, WH Stols, L Rosenbaum, H Khambatta, ZS Quaite-Randall, E Wu, S Kilgore, DC Trent, JD Donnelly, MI AF Eschenfeldt, WH Stols, L Rosenbaum, H Khambatta, ZS Quaite-Randall, E Wu, S Kilgore, DC Trent, JD Donnelly, MI TI DNA from uncultured organisms as a source of 2,5-diketo-D-gluconic acid reductases SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID ALDO-KETO REDUCTASE; L-ASCORBATE SYNTHESIS; ESCHERICHIA-COLI; 3-ALPHA-HYDROXYSTEROID DEHYDROGENASE; METHANOTROPHIC BACTERIA; ENVIRONMENTAL-SAMPLES; GENE-SEQUENCES; PCR; SUPERFAMILY; SOIL AB Total DNA of a population of uncultured organisms was extracted from soil samples, and by using PCR methods, the genes encoding two different 2,5-diketo-D-gluconic acid reductases (DKGRs) were recovered. Degenerate PCR primers based on published sequence information gave internal gene fragments homologous to known DKGRs. Nested primers specific for the internal fragments were combined with random primers to amplify flanking gene fragments from the environmental DNA, and two hypothetical full-length genes were predicted from the combined sequences. Based on these predictions, specific primers were used to amplify the two complete genes in single PCRs. These genes were cloned and expressed in Escherichia coli. The purified gene products catalyzed the reduction of 2,5-diketo-D-gluconic acid to 2-keto-L-gulonic acid. Compared to previously described DKGRs isolated from Corynebacterium spp., these environmental reductases possessed some valuable properties. Both exhibited greater than 20-fold-higher k(cat)/K-m values than those previously determined, primarily as a result of better binding of substrate. The K-m values for the two new reductases were 57 and 67 muM, versus 2 and 13 mM for the Corynebacterium enzymes. Both environmental DKGRs accepted NADH as well as NADPH as a cosubstrate; other DKGRs and most related aldo-keto reductases use only NADPH. In addition, one of the new reductases was more thermostable than known DKGRs. C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. Argonne Natl Lab, Div Biol Sci, Argonne, IL 60439 USA. Genencor Int Inc, Palo Alto, CA 94304 USA. Eastman Chem Co, Kingsport, TN 37662 USA. RP Donnelly, MI (reprint author), Argonne Natl Lab, Div Environm Res, Bldg 202,Rm BE111,9700 S Cass Ave, Argonne, IL 60439 USA. NR 41 TC 41 Z9 53 U1 0 U2 5 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 SEP PY 2001 VL 67 IS 9 BP 4206 EP 4214 DI 10.1128/AEM.67.9.4206-4214.2001 PG 9 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 468FH UT WOS:000170747100060 PM 11526025 ER PT J AU Stoner, DL Geary, MC White, LJ Lee, RD Brizzee, JA Rodman, AC Rope, RC AF Stoner, DL Geary, MC White, LJ Lee, RD Brizzee, JA Rodman, AC Rope, RC TI Mapping microbial biodiversity SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article AB We report the development of a prototype database that "maps" microbial diversity in the context of the geochemical and geological environment and geographic location. When it is fully implemented, scientists will be able to conduct database searches, construct maps containing the information of interest, download files, and enter data over the Internet. C1 Idaho Natl Engn & Environm Lab, Dept Biotechnol, Idaho Falls, ID 83415 USA. Idaho Natl Engn & Environm Lab, Appl Geosci Dept, Idaho Falls, ID 83415 USA. Idaho Natl Engn & Environm Lab, Software Dev Dept, Idaho Falls, ID 83415 USA. Idaho Natl Engn & Environm Lab, Integrated Environm Anal Dept, Idaho Falls, ID 83415 USA. Natl Pk Serv, Yellowstone Ctr Resources, Geog Informat Syst Lab, Yellowstone Natl Pk, WY 82190 USA. RP Stoner, DL (reprint author), Idaho Natl Engn & Environm Lab, Dept Biotechnol, POB 1625,MS 2203, Idaho Falls, ID 83415 USA. NR 3 TC 6 Z9 7 U1 0 U2 1 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 SEP PY 2001 VL 67 IS 9 BP 4324 EP 4328 DI 10.1128/AEM.67.9.4324-4328.2001 PG 5 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 468FH UT WOS:000170747100074 PM 11526039 ER PT J AU Bennett, GR AF Bennett, GR TI Advanced laser-backlit grazing-incidence x-ray imaging systems for inertial confinement fusion research. I. Design SO APPLIED OPTICS LA English DT Article ID NATIONAL-IGNITION-FACILITY; SPHERICALLY BENT CRYSTALS; NIKE KRF LASER; MICROSCOPE; PERFORMANCE; PLASMAS; MIRRORS; ULTRAVIOLET; IMPLOSIONS; SCATTERING AB By use of a focusing configuration analogous to a Gregorian or a Cassegrain telescope, the on-axis aberration of a grazing-incidence spheric-based Kirkpatrick-Baez compound microscope may be precisely corrected. For finite fields, the off-axis performance degrades too rapidly for high-spatial-resolution imaging of even the smallest objects of interest, However, by use of ray-trace optimization it is possible to perturb the system such that the perfect, but impractical, on-axis performance is modestly degraded and uniformly distributed over a chosen object field. By use of this and other performance-enhancing features, two example ultrahigh-spatial-resolution laser-backlit x-ray microscope designs suitable for inertial confinement fusion (ICF) research have been developed. A companion paper [Appl. Opt. 40, 4588 (2001)] describing the tolerance analysis indicates that <0.5-mum spatial resolution at x-ray energies as high as 25 KeV is possible. As a prototype step, simpler noncompound devices are under consideration for Sandia National Laboratories' Z accelerator/Z-Beamlet ICF facility. (C) 2001 Optical Society of America. C1 Ktech Corp Inc, Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Bennett, GR (reprint author), Ktech Corp Inc, Sandia Natl Labs, POB 5800,Mail Stop 1106,POB 5800, Albuquerque, NM 87185 USA. EM grbenne@sandia.gov NR 54 TC 9 Z9 12 U1 1 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 2001 VL 40 IS 25 BP 4570 EP 4587 DI 10.1364/AO.40.004570 PG 18 WC Optics SC Optics GA 467NT UT WOS:000170711200017 PM 18360499 ER PT J AU Bennett, GR Folta, JA AF Bennett, GR Folta, JA TI Advanced laser-backlit grazing -incidence x-ray imaging systems for inertial confinement fusion research. II. Tolerance analysis SO APPLIED OPTICS LA English DT Article ID EXTREME-ULTRAVIOLET LITHOGRAPHY; MULTILAYER REFLECTIVE COATINGS; SPHERICALLY BENT CRYSTALS; PERFORMANCE; MIRRORS; QUALITY AB Two example ultrahigh-spatial-resolution laser-backlit grazing-incidence x-ray microscope designs for inertial confinement fusion (ICF) research have been described [Appl. Opt. 40, 4570 (2001)]. Here details of fabrication, assembly, and optical surface errors that are characteristic of present state-of-the-art superpolished multilayer-coated spherical mirrors are given. They indicate that good image qualities can be expected; in particular, <0.5-mum spatial resolution at very high x-ray energies (up to 25 keV) appears to be feasible: Existing ICF imaging diagnostics approach similar to2 mum spatial at low (<2 keV) energy. The improvement in resolution compared with that of other grazing-incidence devices is attributed to a fortuitous residual on-axis aberration dependence on short wavelengths; recent advances in mirror fabrication, including a new thin-film deposition technique to correct figure errors precisely in one dimension; and novel design. For even higher resolutions, a means of creating precise aspherical mirrors of spheric-quality microroughness may be possible by use of the same deposition technique. (C) 2001 Optical Society of America. C1 Ktech Corp Inc, Sandia Natl Labs, Albuquerque, NM 87185 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Bennett, GR (reprint author), Ktech Corp Inc, Sandia Natl Labs, Mail Stop 1106,POB 5800, Albuquerque, NM 87185 USA. EM grbenne@sandia.gov NR 30 TC 5 Z9 6 U1 1 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1559-128X EI 2155-3165 J9 APPL OPTICS JI Appl. Optics PD SEP 1 PY 2001 VL 40 IS 25 BP 4588 EP 4607 DI 10.1364/AO.40.004588 PG 20 WC Optics SC Optics GA 467NT UT WOS:000170711200018 PM 18360500 ER PT J AU Hsu, HH Chen, J Vasilik, DG AF Hsu, HH Chen, J Vasilik, DG TI Photon radiation dose enhancement at material interfaces SO APPLIED RADIATION AND ISOTOPES LA English DT Article AB Experimental radiation dose-effect studies at a material's interface require high-resolution dose measurements resulting from the exposure of mounted samples on a supporting substrate. Reflections of photons and electrons from the substrate increase the effective dose to the sample relative to dose from the direct beam incident on the unbacked sample. This difficult-to-measure enhancement of effective dose can be calculated easily with Monte Carlo transport codes. We have used the Monte Carlo code, CYLTRAN, to carry out radiation transport and dose calculations in very thin water layers backed by different substrate materials. We present cases with an incident photon beam (15 - 100 keV) on a water medium with five different substrates - mylar, aluminum, copper, silver, and gold. Published by Elsevier Science Ltd. C1 Los Alamos Natl Lab, Hlth Phys Measurements Grp, Los Alamos, NM 87545 USA. RP Vasilik, DG (reprint author), Los Alamos Natl Lab, Hlth Phys Measurements Grp, POB 1663,MS G761, Los Alamos, NM 87545 USA. NR 10 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 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD SEP PY 2001 VL 55 IS 3 BP 323 EP 326 DI 10.1016/S0969-8043(00)00345-6 PG 4 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 460RQ UT WOS:000170322700007 PM 11515654 ER PT J AU Mills, GL McArthur, JV Wolfe, C Aho, JM Rader, RB AF Mills, GL McArthur, JV Wolfe, C Aho, JM Rader, RB TI Changes in fatty acid and hydrocarbon composition of leaves during decomposition in a southeastern blackwater stream SO ARCHIV FUR HYDROBIOLOGIE LA English DT Article DE decomposition; oak leaves; sweetgum leaves; biochemical composition ID AQUATIC BIOTA; SEDIMENTS; ECOSYSTEMS; DETRITUS; LIPIDS; TERRESTRIAL; SHREDDERS; PATTERNS; RIVERS; RATES AB Fatty acid and hydrocarbon composition were determined in decomposing leaf packets of sweetgum (Liquidambar styraciflua) and water oak (Quercus nigra) from a snag habitat in a southeastern blackwater stream. The initial total fatty acid and hydrocarbon concentrations in sweetgum leaves were significantly greater than in the oak species. Higher concentrations of unsaturated fatty acids and dicyclic diterpenoid hydrocarbons accounted for most of this difference. Both of these biochemical subgroups are preferentially degraded relative to the bulk leaf material and other corn pounds within their respective lipid classes. No significant differences remained after 70 days of decomposition. Cuticular fatty acids are selectively preserved and thus, increased relative to noncuticular components during decomposition. The bacterially derived iso- and anteiso-branched-chain fatty acids increased markedly after 23 days. The results of this study suggest that qualitative differences in lipid composition may contribute to the observed difference in overall decomposition rate of leaves between these species. C1 Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. RP Mills, GL (reprint author), Univ Georgia, Savannah River Ecol Lab, Drawer E, Aiken, SC 29802 USA. NR 42 TC 10 Z9 10 U1 0 U2 3 PU E SCHWEIZERBARTSCHE VERLAGS PI STUTTGART PA NAEGELE U OBERMILLER JOHANNESSTRASSE 3A, D 70176 STUTTGART, GERMANY SN 0003-9136 J9 ARCH HYDROBIOL JI Arch. Hydrobiol. PD SEP PY 2001 VL 152 IS 2 BP 315 EP 328 PG 14 WC Limnology; Marine & Freshwater Biology SC Marine & Freshwater Biology GA 491KN UT WOS:000172107700008 ER PT J AU Yasuda, N Fukugita, M Narayanan, VK Lupton, RH Strateva, I Strauss, MA Kim, RSJ Hogg, DW Weinberg, DH Ivezic, Z Shimasaku, K Loveday, J Annis, J Bahcall, NA Blanton, M Brinkmann, J Brunner, RJ Connolly, AJ Csabai, I Doi, M Hamabe, M Ichikawa, SI Ichikawa, T Johnston, DE Knapp, GR Kunszt, PZ Lamb, DQ McKay, TA Munn, JA Nichol, RC Okamura, S Schneider, DP Szokoly, GP Vogeley, MS Watanabe, M York, DG AF Yasuda, N Fukugita, M Narayanan, VK Lupton, RH Strateva, I Strauss, MA Kim, RSJ Hogg, DW Weinberg, DH Ivezic, Z Shimasaku, K Loveday, J Annis, J Bahcall, NA Blanton, M Brinkmann, J Brunner, RJ Connolly, AJ Csabai, I Doi, M Hamabe, M Ichikawa, SI Ichikawa, T Johnston, DE Knapp, GR Kunszt, PZ Lamb, DQ McKay, TA Munn, JA Nichol, RC Okamura, S Schneider, DP Szokoly, GP Vogeley, MS Watanabe, M York, DG TI Galaxy number counts from the Sloan Digital Sky Survey commissioning data SO ASTRONOMICAL JOURNAL LA English DT Article DE cosmology : observations ID LUMINOSITY FUNCTION; REDSHIFT-SURVEY; FIELD; EVOLUTION; DEEP; DENSITY; MODELS; COLORS; STARS AB We present bright galaxy number counts in five broad bands (u', g', r', i', z') from imaging data taken during the commissioning phase of the Sloan Digital Sky Survey (SDSS). The counts are derived from two independent stripes of imaging scans along the celestial equator, one each toward the northern and the southern Galactic cap, covering about 230 and 210 deg(2), respectively. A careful study is made to verify the reliability of the photometric catalog. For galaxies brighter than r* = 16, the catalog produced by automated software is examined against eye inspection of all objects. Statistically meaningful results on the galaxy counts are obtained in the magnitude range 12 less than or equal to r* less than or equal to 21, using a sample of 900,000 galaxies. The counts from the two stripes differ by about 30% at magnitudes brighter than r* = 15.5, consistent with a local 2 sigma fluctuation due to large-scale structure in the galaxy distribution. The shape of the number counts-magnitude relation brighter than r* = 16 is well characterized by N proportional to 10(0.6m), the relation expected for a homogeneous galaxy distribution in a "Euclidean" universe. In the magnitude range 16 3. The accuracy of quasar photometric redshifts does not appear to be dependent upon magnitude to nearly 21st magnitude in i'. Careful calibration of the color-redshift relation to 21st magnitude may allow for the discovery of similar to 10(6) quasar candidates in addition to the 10(5) quasars that the SDSS will confirm spectroscopically. We discuss the efficient selection of quasar candidates from imaging data for use with the photometric redshift technique and the potential scientific uses of a large sample of quasar candidates with photometric redshifts. C1 Penn State Univ, Dept Astron & Astrophys, Davel Lab 525, University Pk, PA 16802 USA. Inst Adv Study, Princeton, NJ 08540 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. Univ Dayton, Dept Phys, Dayton, OH 45469 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15232 USA. Eotvos Lorand Univ, Dept Phys Complex Syst, H-1518 Budapest, Hungary. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Astrophys Inst Potsdam, D-14482 Potsdam, Germany. Apache Point Observ, Sunspot, NM 88349 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Univ Tokyo, Inst Cosm Ray Res, Kashiwa, Chiba 2778582, Japan. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile. USN Observ, Washington, DC 20392 USA. USN Observ, Flagstaff, AZ 86002 USA. Rensselaer Polytech Inst, Dept Phys Appl Phys & Astron, Troy, NY 12180 USA. RP Richards, GT (reprint author), Penn State Univ, Dept Astron & Astrophys, Davel Lab 525, University Pk, PA 16802 USA. RI Csabai, Istvan/F-2455-2012; OI Kunszt, Peter/0000-0003-0933-4763; Csabai, Istvan/0000-0001-9232-9898; Benitez, Narciso/0000-0002-0403-7455 NR 42 TC 70 Z9 70 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2001 VL 122 IS 3 BP 1151 EP 1162 DI 10.1086/322132 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 472RA UT WOS:000170997700005 ER PT J AU Budavari, T Csabai, I Szalay, AS Connolly, AJ Szokoly, GP Vanden Berk, DE Richards, GT Weinstein, MA Schneider, DP Benitez, N Brinkman, J Brunner, R Hall, PB Hennessy, GS Ivezic, Z Kunszt, PZ Munn, JA Nichol, RC Pier, JR York, DG AF Budavari, T Csabai, I Szalay, AS Connolly, AJ Szokoly, GP Vanden Berk, DE Richards, GT Weinstein, MA Schneider, DP Benitez, N Brinkman, J Brunner, R Hall, PB Hennessy, GS Ivezic, Z Kunszt, PZ Munn, JA Nichol, RC Pier, JR York, DG TI Photometric redshifts from reconstructed quasar templates SO ASTRONOMICAL JOURNAL LA English DT Article DE galaxies : distances and redshifts; galaxies : photometry; quasars : general; methods : statistical ID HUBBLE DEEP FIELD; DIGITAL SKY SURVEY; CREATING SPECTRAL TEMPLATES; BROAD-BAND PHOTOMETRY; GALAXIES; EVOLUTION; CATALOG; COLORS; SYSTEM AB From Sloan Digital Sky Survey (SDSS) commissioning photometric and spectroscopic data, we investigate the utility of photometric redshift techniques in the task of estimating QSO redshifts. We consider empirical methods (e.g., nearest neighbor searches and polynomial fitting), standard spectral template fitting, and hybrid approaches (i.e., training spectral templates from spectroscopic and photometric observations of QSOs). We find that in all cases, because of the presence of strong emission lines within the QSO spectra, the nearest neighbor and template-fitting methods are superior to the polynomial-fitting approach. Applying a novel reconstruction technique, we can, from the SDSS multicolor photometry, reconstruct a statistical representation of the underlying SEDs of the SDSS QSOs. Although the reconstructed templates are based on only broadband photometry, the common emission lines present within the QSO spectra can be recovered in the resulting spectral energy distributions. The technique should be useful in searching for spectral differences among QSOs at a given redshift, in searching for spectral evolution of QSOs, in comparing photometric redshifts for objects beyond the SDSS spectroscopic sample with those in the well-calibrated photometric redshifts for objects brighter than 20th magnitude, and in searching for systematic and time-variable effects in the SDSS broadband photometric and spectral photometric calibrations. C1 Eotvos Lorand Univ, Dept Phys Complex Syst, H-1518 Budapest, Hungary. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Univ Pittsburgh, Dept Phys & Astron, Pittsburgh, PA 15260 USA. Astrophys Inst Potsdam, D-14482 Potsdam, Germany. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Penn State Univ, Dept Astron & Astrophys, Davey Lab 525, University Pk, PA 16802 USA. Apache Point Observ, Sunspot, NM 88349 USA. CALTECH, Dept Astron, Pasadena, CA 91125 USA. Princeton Univ Observ, Princeton, NJ 08544 USA. Pontificia Univ Catolica Chile, Dept Astron & Astrofis, Santiago 22, Chile. USN Observ, Washington, DC 20392 USA. Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15232 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. RP Budavari, T (reprint author), Eotvos Lorand Univ, Dept Phys Complex Syst, Pf 32, H-1518 Budapest, Hungary. RI Csabai, Istvan/F-2455-2012; OI Kunszt, Peter/0000-0003-0933-4763; Csabai, Istvan/0000-0001-9232-9898; Benitez, Narciso/0000-0002-0403-7455 NR 27 TC 56 Z9 56 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2001 VL 122 IS 3 BP 1163 EP 1171 DI 10.1086/322131 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 472RA UT WOS:000170997700006 ER PT J AU Roe, HG Gavel, D Max, C de Pater, I Gibbard, S Macintosh, B Baines, KH AF Roe, HG Gavel, D Max, C de Pater, I Gibbard, S Macintosh, B Baines, KH TI Near-infrared observations of Neptune's tropospheric cloud layer with the Lick Observatory adaptive optics system SO ASTRONOMICAL JOURNAL LA English DT Article DE infrared radiation; instrumentation : adaptive optics; planets and satellites : individual (Neptune) ID ATMOSPHERIC STRUCTURE; ABSORPTION SPECTRA; H-2-HE PAIRS; TEMPERATURES; METHANE; BAND; VARIABILITY; BRIGHTNESS; SCATTERING; OVERTONE AB We provide one of the first constraints on the combined infrared single-scattering albedo and opacity of Neptune's upper tropospheric cloud layer. For the observations, we used the adaptive optics system on the Lick Observatory's 3 m Shane Telescope (Mount Hamilton, California). The cloud layer is thought to be composed H(2)S of and extend up to 3.5-4.5 bars. Previously, the single-scattering albedo was measured in the range 0.2-0.94 mum and found to be extremely high (>0.8), but decreasing with increasing wavelength. Assuming an optically thick cloud, we find the best-Dt single-scattering albedo of a 3.5 bar layer to be at 0.23(-0.08)(+0.07) at 1.27 mum and 0.18(-0.04)(+0.03) at 1.56 mum. Uncertainties in the column density of haze above the cloud layer, and from deconvolution to remove contaminating light scattered by the point-spread function from infrared-bright features, indicate that the cloud could be even darker, but it is unlikely to be brighter than we report. The cloud particles could be brighter than we report if the total near-infrared opacity of the cloud is very low or the cloud's scattering phase function is significantly more forward-scattering at 1.2-1.6 mum than at 0.75 mum. C1 Univ Calif Berkeley, Dept Astron, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. RP Roe, HG (reprint author), Univ Calif Berkeley, Dept Astron, 601 Campbell Hall, Berkeley, CA 94720 USA. EM hroe@doty.berkeley.edu OI Max, Claire/0000-0003-0682-5436 NR 35 TC 8 Z9 8 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-6256 J9 ASTRON J JI Astron. J. PD SEP PY 2001 VL 122 IS 3 BP 1636 EP 1643 DI 10.1086/322125 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 472RA UT WOS:000170997700044 ER PT J AU Trudolyubov, SP AF Trudolyubov, SP TI On the two types of steady hard X-ray states of GRS 1915+105 SO ASTROPHYSICAL JOURNAL LA English DT Article DE black hole physics; stars : individual (GRS 1915+105); X-rays : stars ID QUASI-PERIODIC OSCILLATIONS; HOLE CANDIDATE GRS-1915+105; SUPERLUMINAL SOURCE; RXTE OBSERVATIONS; ACCRETION DISKS; BLACK-HOLES; VARIABILITY; COMPONENTS; SPECTRA; QPO AB Using data from five years of Rossi X-Ray Timing Explorer observations, we investigate the X-ray spectral and timing properties of GRS 1915+105 during the hard steady states. The broadband energy spectrum of the source during these periods is dominated by an extended hard component with a characteristic cutoff or break at similar to 10-120 keV. The power density spectrum of the source's rapid aperiodic variability shows a dominant band-limited white-noise component breaking at a few hertz, accompanied by a group of strong quasi-periodic oscillation peaks and in some cases an additional high-frequency noise component with a characteristic cutoff at similar to 60-80 Hz. According to the results of our simultaneous X-ray spectral and timing analysis, the behavior of the source during the hard steady states can be reduced to two major, distinct types. (1) Type I states: The dominant hard component of the energy spectrum has characteristic quasi-exponential cutoff at 60-120 keV. The broadband power density spectrum of the source shows a significant high-frequency noise component with a cutoff at similar to 60-80 Hz. (2) Type II states: The hard spectral component has a break in its slope at similar to 12-20 keV. The high-frequency part of the power density spectrum fades quickly, lacking significant variability at frequencies higher than similar to 30 Hz. These two types of X-ray hard states are also clearly distinguished by their properties in the radio band: while during the type I observations the source tends to be "radio quiet," the type II observations are characterized by a high level of radio flux ("plateau" radio states). In this work we demonstrate the aforementioned differences using data from 12 representative hard steady state observations. We conclude that the difference between these two types can probably be explained in terms of a difference in accretion flow structure in the immediate vicinity of the compact object due to the presence of relativistic outflow of matter. C1 Los Alamos Natl Lab, Div NIS2, Los Alamos, NM 87545 USA. Russian Acad Sci, Inst Space Res, Moscow 117810, Russia. RP Trudolyubov, SP (reprint author), Los Alamos Natl Lab, Div NIS2, POB 1663, Los Alamos, NM 87545 USA. NR 29 TC 30 Z9 30 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2001 VL 558 IS 1 BP 276 EP 282 DI 10.1086/322466 PN 1 PG 7 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 469CB UT WOS:000170794300027 ER PT J AU Goldhaber, G Groom, DE Kim, A Aldering, G Astier, P Conley, A Deustua, SE Ellis, R Fabbro, S Fruchter, AS Goobar, A Hook, I Irwin, M Kim, M Knop, RA Lidman, C McMahon, R Nugent, PE Pain, R Panagia, N Pennypacker, CR Perlmutter, S Ruiz-Lapuente, P Schaefer, B Walton, NA York, T AF Goldhaber, G Groom, DE Kim, A Aldering, G Astier, P Conley, A Deustua, SE Ellis, R Fabbro, S Fruchter, AS Goobar, A Hook, I Irwin, M Kim, M Knop, RA Lidman, C McMahon, R Nugent, PE Pain, R Panagia, N Pennypacker, CR Perlmutter, S Ruiz-Lapuente, P Schaefer, B Walton, NA York, T CA Supernova Cosmology Project TI Timescale stretch parameterization of Type Ia supernova B-band light curves SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmological parameters; galaxies : high-redshift; supernovae : general ID GAMMA-RAY BURSTS; TIME DILATION; EXPLOSION MODELS; HUBBLE CONSTANT; RISE TIMES; RED SHIFTS; UNIVERSE; REDSHIFTS; GALAXIES; LAMBDA AB R-band intensity measurements along the light curve of Type Ia supernovae (SNe Ia) discovered by the Supernova Cosmology Project (SCP) are fitted in brightness to templates allowing a free parameter the time-axis width factor w drop s(1 + z). The data points are then individually aligned in the time axis, normalized, and K-corrected back to the rest frame, after which the nearly 1300 normalized intensity measurements are found to lie on a well-determined common rest-frame B-band curve, which we call the "composite curve." The same procedure is applied to 18 low-redshift Calan/Tololo SNe with z < 0.11; these nearly 300 B-band photometry points are found to lie on the composite curve equally well. The SCP search technique produces several measurements before maximum light for each supernova. We demonstrate that the linear stretch factor, s, which parameterizes the light-curve timescale, appears independent of z, and applies equally well to the declining and rising parts of the light curve. In fact, the B-band template that best fits this composite curve fits the individual supernova photometry data when stretched by a factor s with chi (2)/dof approximate to 1-thus, as well as any parameterization can, given the current data sets. The measurement of the date of explosion, however, is model dependent and not tightly constrained by the current data. We also demonstrate the 1 + z light-curve time-axis broadening expected from cosmological expansion. This argues strongly against alternative explanations, such as tired light, for the redshift of distant objects. C1 EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Univ Paris 06, CNRS, IN2P3, Lab Phys Nucl Hautes Energies, F-75252 Paris, France. Univ Paris 07, CNRS, Lab Phys Nucl Hautes Energies, F-75252 Paris, France. Univ Cambridge, Inst Astron, Cambridge CB3 0HA, England. Space Telescope Sci Inst, Baltimore, MD 21218 USA. Univ Stockholm, Fysikum, S-11385 Stockholm, Sweden. Univ Edinburgh, Inst Astron, Edinburgh EH9 3HJ, Midlothian, Scotland. La Silla Observ, European So Observ, La Serena, Chile. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Barcelona, Dept Astron, E-08028 Barcelona, Spain. Yale Univ, Dept Astron, New Haven, CT 06520 USA. Isaac Newton Grp, Las Palmas Gran Canaria, Spain. RP EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. EM gerson@lbl.gov RI Perlmutter, Saul/I-3505-2015; OI Perlmutter, Saul/0000-0002-4436-4661; York, Thomas/0000-0002-6829-5816 NR 56 TC 195 Z9 195 U1 3 U2 6 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2001 VL 558 IS 1 BP 359 EP 368 DI 10.1086/322460 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 469CB UT WOS:000170794300033 ER PT J AU Jimenez-Garate, MA Raymond, JC Liedahl, DA Hailey, CJ AF Jimenez-Garate, MA Raymond, JC Liedahl, DA Hailey, CJ TI X-ray line emission from evaporating and condensing accretion disk atmospheres SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; atomic processes; instabilities; line : formation; X-rays : binaries ID THERMAL-INSTABILITY; BINARY-SYSTEMS; PLASMA AB We model the X-rays reprocessed by an accretion disk in a fiducial low-mass X-ray binary system with a neutron star primary. An atmosphere, or the intermediate region between the optically thick disk and a Compton temperature corona, is photoionized by the neutron star continuum. X-ray lines from the recombination of electrons with ions dominate the atmosphere emission and should be observable with the Chandra and XMM-Newton high-resolution spectrometers. The self-consistent disk geometry agrees well with optical observations of these systems, with the atmosphere shielding the companion from the neutron star. At a critical depth range, the disk gas has one thermally unstable and two stable solutions. A clear difference between the model spectra exists between evaporating and condensing disk atmospheres. This difference should be observable in high-inclination X-ray binaries, or whenever the central continuum is blocked by absorbing material and the extended disk emission is not. C1 MIT, Ctr Space Res, Cambridge, MA 02139 USA. Columbia Univ, Astrophys Lab, New York, NY 10027 USA. Lawrence Livermore Natl Lab, Dept Phys & Adv Technol, Livermore, CA 94550 USA. Ctr Astrophys, Cambridge, MA 02138 USA. RP Jimenez-Garate, MA (reprint author), MIT, Ctr Space Res, 77 Massachusetts Ave,NE80, Cambridge, MA 02139 USA. NR 27 TC 14 Z9 14 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD SEP 1 PY 2001 VL 558 IS 1 BP 448 EP 452 PN 1 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 469CB UT WOS:000170794300042 ER PT J AU Streets, DG Gupta, S Waldhoff, ST Wang, MQ Bond, TC Bo, YY AF Streets, DG Gupta, S Waldhoff, ST Wang, MQ Bond, TC Bo, YY TI Black carbon emissions in China SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE black carbons; China; biofuels; emission factors; coal combustion ID PARTICULATE ELEMENTAL CARBON; COAL COMBUSTION; TRACE-ELEMENTS; LIGHT-DUTY; FLY-ASH; VEHICLES; PARTICLES; CLIMATE; PLANT; ASIA AB Black carbon (BC) is an important aerosol species because of its global and regional influence on radiative forcing and its local effects on the environment and human health. We have estimated the emissions of BC in China, where roughly one-fourth of global anthropogenic emissions is believed to originate. China's high rates of usage of coal and biofuels are primarily responsible for high BC emissions. This paper pays particular attention to the application of appropriate emission factors for China and the attenuation of these emissions where control devices are used. Nevertheless, because of the high degree of uncertainty associated with BC emission factors, we provide ranges of uncertainty for our emission estimates, which are approximately a factor of eight. In our central case, we calculate that BC emissions in China in 1995 were 1342 Gg, about 83% being generated by the residential combustion of coal and biofuels, We estimate that BC emissions could fall to 1224 Gg by 2020. This 9% decrease in BC emissions can be contrasted with the expected increase of 50% in energy use; the reduction will be obtained because of a transition to more advanced technology, including greater use of coal briquettes in place of raw coal in cities and towns. The increased use of diesel vehicles in the future will result in a greater share of the transport sector in total BC emissions. Spatially, BC emissions are predominantly distributed in an east-west swath across China's heartland, where the rural use of coal and biofuels for cooking and heating is widespread. This is in contrast Lo the emissions of most other anthropogenically derived air pollutants. which are closely tied to population and industrial centers. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. NOAA, Pacific Marine Environm Lab, Seattle, WA 98115 USA. Beijing Municipal Inst Labor Protect, Dept Air Pollut Control, Beijing 100054, Peoples R China. RP Streets, DG (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Bond, Tami/A-1317-2013; OI Bond, Tami/0000-0001-5968-8928; Streets, David/0000-0002-0223-1350 NR 76 TC 281 Z9 344 U1 15 U2 118 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD SEP PY 2001 VL 35 IS 25 BP 4281 EP 4296 DI 10.1016/S1352-2310(01)00179-0 PG 16 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 468GF UT WOS:000170749200007 ER PT J AU Liu, DL Nazaroff, WW AF Liu, DL Nazaroff, WW TI Modeling pollutant penetration across building envelopes SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE exposure; infiltration; ozone; particles; penetration factor; reaction probability ID INDOOR AIR-QUALITY; PARTICLE DEPOSITION; OZONE; SURFACES; REMOVAL; GASES; RATES; FLOW AB As air infiltrates through unintentional openings in building envelopes, pollutants may interact with adjacent surfaces. Such interactions can alter human exposure to air pollutants of outdoor origin. We present modeling explorations of the proportion of particles and reactive gases (e.g., ozone) that penetrate building envelopes as air enters through cracks and wall cavities. Calculations were performed for idealized rectangular cracks, assuming regular geometry, smooth inner crack surface and steady airflow. Particles of 0.1-1.0 mum diameter are predicted to have the highest penetration efficiency, nearly unity for crack heights of 0.25 mm or larger, assuming a pressure difference of 4 Pa or greater and a flow path length of 3 cm or less. Supermicron and ultrafine particles are significantly removed by means of gravitational settling and Brownian diffusion, respectively. In addition to crack geometry, ozone penetration depends on its reactivity with crack surfaces, as parameterized by the reaction probability. For reaction probabilities less than similar to 10(-5), penetration is complete for cracks heights greater than similar to1 mm. However, penetration through mm scale cracks is small if the reaction probability is similar to 10(-4) or greater. For wall cavities, fiberglass insulation is an efficient particle filter, but particles would penetrate efficiently through uninsulated wall cavities or through insulated cavities with significant airflow bypass. The ozone reaction probability on fiberglass fibers was measured to be 10(-7) for fibers previously exposed to high ozone levels and 6 x 10(-6) for unexposed fibers. Over this range, ozone penetration through fiberglass insulation would vary from > 90% to similar to 10-40%. Thus, under many conditions penetration is high; however, there are realistic circumstances in which building envelopes can provide substantial pollutant removal. Not enough is yet known about the detailed nature of pollutant penetration leakage paths to reliably predict infiltration into real buildings. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Lawrence Berkeley Natl Lab, Indoor Environm Dept, Berkeley, CA 94720 USA. Univ Calif Berkeley, Environm Engn Program, Dept Civil & Environm Engn, Berkeley, CA 94720 USA. RP Nazaroff, WW (reprint author), Lawrence Berkeley Natl Lab, Indoor Environm Dept, Berkeley, CA 94720 USA. RI Nazaroff, William/C-4106-2008 OI Nazaroff, William/0000-0001-5645-3357 NR 29 TC 121 Z9 129 U1 7 U2 51 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD SEP PY 2001 VL 35 IS 26 BP 4451 EP 4462 DI 10.1016/S1352-2310(01)00218-7 PG 12 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 471MK UT WOS:000170933000008 ER PT J AU Kotamarthi, VR Gaffney, JS Marley, NA Doskey, PV AF Kotamarthi, VR Gaffney, JS Marley, NA Doskey, PV TI Heterogeneous NOx chemistry in the polluted PBL SO ATMOSPHERIC ENVIRONMENT LA English DT Article ID PARTICULATE AIR-POLLUTION; IN-SITU MEASUREMENTS; NITROUS-ACID; NITRIC-ACID; AEROSOLS; TROPOSPHERE; ATMOSPHERE; URBAN; OH; CONVERSION AB The significance of heterogeneous mechanisms in controlling gas-phase NOx (NO, NO2) mixing ratios in polluted urban air, especially during nighttime, is not well established. Several recent studies have suggested that carbon soot can provide an effective surface for mediating the inter conversion among several NOy members. However, a number of such reactions reported in the literature have widely varying reaction probabilities and often conflicting pathways. We evaluated several of these reactions and choose the NO2 conversion to HONO on the surface of soot particles for further analysis with a box photochemical model. These calculations show that the conversion of NO2 to HONO on particle surfaces produces a large, measurable signal (up to several parts per billion) in nighttime HONO mixing ratios. Inclusion of this reaction was also shown to have significant impacts on ozone, OH and HO2 in the polluted planetary boundary layer (PBL). The sensitivity of these results to the different reaction rate probabilities (gamma) and particle surface areas was also examined, Results are then evaluated to find the combination of gamma and surface areas that would mostly likely occur in the PBL within the limitations of the model. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Kotamarthi, VR (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. OI Kotamarthi, Veerabhadra Rao/0000-0002-2612-7590 NR 37 TC 18 Z9 20 U1 2 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD SEP PY 2001 VL 35 IS 26 BP 4489 EP 4498 DI 10.1016/S1352-2310(01)00221-7 PG 10 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA 471MK UT WOS:000170933000012 ER PT J AU Holmes, I Bruno, WJ AF Holmes, I Bruno, WJ TI Evolutionary HMMs: a Bayesian approach to multiple alignment SO BIOINFORMATICS LA English DT Article ID HIDDEN MARKOV-MODELS; MAXIMUM-LIKELIHOOD ALIGNMENT; SEQUENCE ALIGNMENT; DNA-SEQUENCES; SUBSTITUTION MATRICES; PROTEIN SEQUENCES; PHYLOGENY; ALGORITHM; PROGRAMS; HOMOLOGY AB Motivation: We review proposed syntheses of probabilistic sequence alignment, profiling and phylogeny. We develop a multiple alignment algorithm for Bayesian inference in the links model proposed by Thorne et el. (1991, J. Mol, Evol., 33, 114-124). The algorithm, described in detail in Section 3, samples from and/or maximizes the posterior distribution over multiple alignments for any number of DNA or protein sequences, conditioned on a phylogenetic tree. The individual sampling and maximization steps of the algorithm require no more computational resources than pairwise alignment. Methods: We present a software implementation (Handel) of our algorithm and report test results on (I) simulated data sets and (ii) the structurally informed protein alignments of BALiBASE Results: We find that the mean sum-of-pairs score (a measure of residue-pair correspondence) for the BAliBASE alignments is only 13% lower for Handel than for CLUSTALW (Thompson et al., 1994, Nucleic Acids Res., 22, 4673-4680), despite the relative simplicity of the links model (CLUSTALW uses affine gap scores and increased penalties for indels in hydrophobic regions). With reference to these benchmarks, we discuss potential improvements to the links model and implications for Bayesian multiple alignment and phylogenetic profiling. C1 Los Alamos Natl Lab, Grp T10, Los Alamos, NM 87545 USA. RP Holmes, I (reprint author), Los Alamos Natl Lab, Grp T10, POB 1663, Los Alamos, NM 87545 USA. OI Holmes, Ian/0000-0001-7639-5369 NR 49 TC 91 Z9 91 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1367-4803 J9 BIOINFORMATICS JI Bioinformatics PD SEP PY 2001 VL 17 IS 9 BP 803 EP 820 DI 10.1093/bioinformatics/17.9.803 PG 18 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 482FW UT WOS:000171566400005 PM 11590097 ER PT J AU Heinrich, V Ritchie, K Mohandas, N Evans, E AF Heinrich, V Ritchie, K Mohandas, N Evans, E TI Elastic thickness compressibilty of the red cell membrane SO BIOPHYSICAL JOURNAL LA English DT Article ID INTERFERENCE CONTRAST MICROSCOPY; ENTROPY-DRIVEN TENSION; FLUID MEMBRANES; ERYTHROCYTE CYTOSKELETON; STERIC INTERACTION; SPECTRIN; SKELETON; MICROINTERFEROMETRY AB We have used an ultrasensitive force probe and optical interferometry to examine the thickness compressibility of the red cell membrane in situ. Pushed into the centers of washed-white red cell ghosts lying on a coverglass, the height of the microsphere-probe tip relative to its closest approach on the adjacent glass surface revealed the apparent material thickness, which began at similar to 90 nm per membrane upon detection of contact (force similar to1-2 pN). With further impingement, the apparent thickness per membrane diminished over a soft compliant regime that spanned similar to 40 nm and stiffened on approach to similar to 50 nm under forces of similar to 100 pN. The same force-thickness response was obtained on recompression after retraction of the probe, which demonstrated elastic recoverability. Scaled by circumferences of the microspheres, the forces yielded energies of compression per area which exhibited an inverse distance dependence resembling that expected for flexible polymers. Attributed to the spectrin component of the membrane cytoskeleton, the energy density only reached one thermal energy unit (k(B)T) per spectrin tetramer near maximum compression. Hence, we hypothesized that the soft compliant regime probed in the experiments represented the compressibility of the outer region of spectrin loops and that the stiff regime < 50 nm was the response of a compact mesh of spectrin backed by a hardcore structure. To evaluate this hypothesis, we used a random flight theory for the entropic elasticity of polymer loops to model the spectrin network. We also examined the possibility that additional steric repulsion and apparent thickening could arise from membrane thermal-bending excitations. Fixing the energy scale to k(B)T/spectrin tetramer, the combined elastic response of a network of ideal polymer loops plus the membrane steric interaction correlated well with the measured dependence of energy density on distance for a statistical segment length of similar to5 nm for spectrin (i.e., free chain end-to-end length of similar to 29 nm) and a hardcore limit of similar to 30 nm for underlying structure. C1 Boston Univ, Dept Biomed Engn, Boston, MA 02215 USA. Nagoya Univ, Dept Biol Sci, Nagoya, Aichi, Japan. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 2A6, Canada. RP Evans, E (reprint author), Univ British Columbia, Dept Phys & Pathol, 6224 Agr Rd, Vancouver, BC V6T 2A6, Canada. RI Heinrich, Volkmar/D-1169-2009 FU NHLBI NIH HHS [HL31579] NR 33 TC 53 Z9 53 U1 0 U2 10 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD SEP PY 2001 VL 81 IS 3 BP 1452 EP 1463 PG 12 WC Biophysics SC Biophysics GA 465QE UT WOS:000170600800022 PM 11509359 ER PT J AU Dale, VH Joyce, LA McNulty, S Neilson, RP Ayres, MP Flannigan, MD Hanson, PJ Irland, LC Lugo, AE Peterson, CJ Simberloff, D Swanson, FJ Stocks, BJ Wotton, BM AF Dale, VH Joyce, LA McNulty, S Neilson, RP Ayres, MP Flannigan, MD Hanson, PJ Irland, LC Lugo, AE Peterson, CJ Simberloff, D Swanson, FJ Stocks, BJ Wotton, BM TI Climate change and forest disturbances SO BIOSCIENCE LA English DT Article ID UNITED-STATES FORESTS; GLOBAL CHANGE; TROPICAL CYCLONES; TREE MORTALITY; IMPACTS; ECOSYSTEMS; HURRICANES; VEGETATION; FREQUENCY; INVASIONS C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. USDA, Forest Serv, Ft Collins, CO 80523 USA. USDA, Forest Serv, Raleigh, NC 27606 USA. USDA, Forest Serv, Pacific NW Res Stn, Corvallis, OR 97331 USA. Dartmouth Coll, Dept Biol Sci, Hanover, NH 03755 USA. Canadian Forest Serv, Edmonton, AB T6H 3S5, Canada. Irland Grp, Winthrop, ME 04364 USA. USDA, Forest Serv, Int Inst Trop Forestry, Rio Piedras, PR 00928 USA. Univ Georgia, Dept Bot, Athens, GA 30602 USA. Univ Tennessee, Dept Ecol & Evolutionary Biol, Knoxville, TN 37996 USA. Canadian Forest Serv, Sault St Marie, ON P6A 5M7, Canada. RP Dale, VH (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Neilson, Ronald/A-8588-2009; Dale, Virginia/B-6023-2009; Hanson, Paul J./D-8069-2011; Peterson, A. Townsend/I-5697-2013; Flannigan, Michael/G-6996-2015 OI Hanson, Paul J./0000-0001-7293-3561; Peterson, A. Townsend/0000-0003-0243-2379; Flannigan, Michael/0000-0002-9970-5363 NR 71 TC 731 Z9 779 U1 39 U2 290 PU AMER INST BIOLOGICAL SCI PI WASHINGTON PA 1444 EYE ST, NW, STE 200, WASHINGTON, DC 20005 USA SN 0006-3568 J9 BIOSCIENCE JI Bioscience PD SEP PY 2001 VL 51 IS 9 BP 723 EP 734 DI 10.1641/0006-3568(2001)051[0723:CCAFD]2.0.CO;2 PG 12 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 473ND UT WOS:000171049700009 ER PT J AU Hansen, AJ Neilson, RR Dale, VH Flather, CH Iverson, LR Currie, DJ Shafer, S Cook, R Bartlein, PJ AF Hansen, AJ Neilson, RR Dale, VH Flather, CH Iverson, LR Currie, DJ Shafer, S Cook, R Bartlein, PJ TI Global change in forests: Responses of species, communities, and biomes SO BIOSCIENCE LA English DT Article ID EASTERN UNITED-STATES; LAND-USE CHANGE; CLIMATE-CHANGE; POTENTIAL CHANGES; FUTURE CLIMATE; TREE; MODEL; VEGETATION; RICHNESS; DISTRIBUTIONS C1 Montana State Univ, Dept Ecol, Bozeman, MT 59717 USA. USDA, Forest Serv, Corvallis, OR 97331 USA. Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. USDA, Forest Serv, Rocky Mt Res Stn, Ft Collins, CO 80526 USA. USDA, Forest Serv, NE Res Stn, Delaware, OH 43066 USA. Univ Ottawa, Dept Biol, Ottawa, ON K1N 6N5, Canada. Univ Oregon, Dept Geog, Eugene, OR 97403 USA. Colorado State Univ, Dept Fishery & Wildlife Biol, Ft Collins, CO 80523 USA. RP Hansen, AJ (reprint author), Montana State Univ, Dept Ecol, Bozeman, MT 59717 USA. EM hansen@montana.edu RI Dale, Virginia/B-6023-2009; Bartlein, Patrick/E-4643-2011; Flather, Curtis/G-3577-2012; OI Bartlein, Patrick/0000-0001-7657-5685; Flather, Curtis/0000-0002-0623-3126; Currie, David J./0000-0002-4906-2363 NR 64 TC 203 Z9 219 U1 9 U2 75 PU AMER INST BIOLOGICAL SCI PI WASHINGTON PA 1444 EYE ST, NW, STE 200, WASHINGTON, DC 20005 USA SN 0006-3568 J9 BIOSCIENCE JI Bioscience PD SEP PY 2001 VL 51 IS 9 BP 765 EP 779 DI 10.1641/0006-3568(2001)051[0765:GCIFRO]2.0.CO;2 PG 15 WC Biology SC Life Sciences & Biomedicine - Other Topics GA 473ND UT WOS:000171049700012 ER PT J AU Sanders, CA Rodriguez, M Greenbaum, E AF Sanders, CA Rodriguez, M Greenbaum, E TI Stand-off tissue-based biosensors for the detection of chemical warfare agents using photosynthetic fluorescence induction SO BIOSENSORS & BIOELECTRONICS LA English DT Article DE biosensor; fluorescence; algae; cyanobacteria; chemical warfare; photosynthesis; stand-off detection; tabun; sarin; tributylamine; dibutyl sulfide ID CHLOROPHYLL FLUORESCENCE; WATER-STRESS; CYANOBACTERIA; SPECTROMETRY; TOXICITY; CYANIDE; CELL AB Tissue biosensors made from immobilized whole-cell photosynthetic microorganisms have been developed for the detection of airborne chemical warfare agents and simulants. The sensor read-out is based on well-known principles of fluorescence induction by living photosynthetic tissue. Like the cyanobacteria and algae from which they were constructed, the sensors are robust and mobile. The fluorescence signal from the sensors was stable after 40 days, storage and they can be launched or dropped into suspected danger zones. Commercially available hand-held fluorometric detector systems were used to measure Photosystem II (PSII) photochemical efficiency of green algae and cyanobacteria entrapped on filter paper disks. Toxic agents flowing in the gas stream through the sensors can alter the characteristic fluorescence induction curves with resultant changes in photochemical yields. Tabun (GA), satin (GB), mustard agent, tributylamine (TBA) (a sarin stabilizer), and dibutyl sulfide (DBS) (a mustard agent analog) were tested. Upper threshold limits of detectability for GA, TBA, and DBS are reported. With additional research and development, these biosensors may find application in stand-off detection of chemical and perhaps biological warfare agents under real-world conditions. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. Univ Tennessee, Ctr Environm Biotechnol, Knoxville, TN 37996 USA. Univ Tennessee, Grad Sch Genome Sci & Technol, Knoxville, TN 37996 USA. RP Greenbaum, E (reprint author), Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. NR 29 TC 55 Z9 58 U1 4 U2 19 PU ELSEVIER ADVANCED TECHNOLOGY PI OXFORD PA OXFORD FULFILLMENT CENTRE THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0956-5663 J9 BIOSENS BIOELECTRON JI Biosens. Bioelectron. PD SEP PY 2001 VL 16 IS 7-8 BP 439 EP 446 DI 10.1016/S0956-5663(01)00158-0 PG 8 WC Biophysics; Biotechnology & Applied Microbiology; Chemistry, Analytical; Electrochemistry; Nanoscience & Nanotechnology SC Biophysics; Biotechnology & Applied Microbiology; Chemistry; Electrochemistry; Science & Technology - Other Topics GA 476ZD UT WOS:000171257900004 PM 11544038 ER PT J AU Frauenfelder, H McMahon, BH AF Frauenfelder, H McMahon, BH TI Relaxations and fluctuations in myoglobin SO BIOSYSTEMS LA English DT Article; Proceedings Paper CT 4th Agora Meeting on Fluctuations in Biological Systems CY AUG 03-07, 1999 CL SIGTUNA, SWEDEN DE myoglobin; protonation state; flash photolysis ID LIGAND-BINDING; HEME-PROTEINS; DYNAMICS; CARBONMONOXYMYOGLOBIN; PHOTODISSOCIATION; POCKET; CO AB One major goal of biological physics is the discovery and understanding of the concepts and laws that govern biomolecules, in particular proteins. Since there exist at least 105 different proteins, the choice of a suitable prototype is necessary. Myoglobin (Mb) has for many years played the role of such a prototype. It appears to be simple enough so that many of its properties can be understood, yet it is complex enough to display many of the fascinating characteristics of biomolecules. One major achievement in the study of any protein would be the establishment of convincing connections among structure, kinetics, energy landscape, dynamics, and function. We believe that this goal has not yet been reached in any protein, but the present knowledge of Mb gives some hope that the end is near in this case. Here, we sketch some of the results that have been obtained in the past 50 or more years in the research on Mb, obtained by an army of investigators. Published by Elsevier Science Ireland Ltd. C1 Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Frauenfelder, H (reprint author), Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. NR 25 TC 16 Z9 17 U1 1 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0303-2647 J9 BIOSYSTEMS JI Biosystems PD SEP-OCT PY 2001 VL 62 IS 1-3 BP 3 EP 8 AR PII S0303-2647(01)00132-0 DI 10.1016/S0303-2647(01)00132-0 PG 6 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA 581VY UT WOS:000177316000002 PM 11595314 ER PT J AU Boussaid, A Cai, YJ Robinson, J Gregg, DJ Nguyen, Q Saddler, JN AF Boussaid, A Cai, YJ Robinson, J Gregg, DJ Nguyen, Q Saddler, JN TI Sugar recovery and fermentability of hemicellulose hydrolysates from steam-exploded softwoods containing bark SO BIOTECHNOLOGY PROGRESS LA English DT Article ID SACCHAROMYCES-CEREVISIAE; ETHANOL FERMENTATION; PICHIA-STIPITIS; PINUS-RADIATA; ACID; DETOXIFICATION; EXPLOSION; WOOD AB The hemicellulose sugar recovery and ethanol production obtained from SO2-catalyzed steam explosion of a mixed white fir (70%) and ponderosa pine (30%) feedstock containing bark (9% dry weight/dry weight) was assessed. More than 90% of the available hemicellulose sugars could be recovered in the hydrolysate obtained after steam explosion at 195 degreesC, 2.38 min, and 3.91% SO2, with 59% of the original hemicellulose sugars detected in a monomeric form. Despite this high sugar recovery, this hydrolysate showed low ethanol yield (64% of theoretical yield) when fermented with a spent sulfite liquor-adapted strain of Saccharomyces cerevisiae. In contrast, most hydrolysates prepared at higher steam explosion severity showed comparable or higher ethanol yields. Furthermore, the hydrolysates prepared from bark-free feedstock showed better fermentability (87% of theoretical yield) despite containing higher concentration of known inhibitors. The ethanol yield from the hydrolysate prepared from a bark-containing wood sample could be improved to 81% by an extra stage acid hydrolysis (121 degreesC for 1 h in 3% sulfuric acid). This extra stage acid hydrolysis and steam explosion at higher severity conditions seem to improve the fermentability of the hydrolysates by transforming certain inhibitory compounds present in the hydrolysates prepared from the bark-containing feedstock and thus lowering their inhibitory effect on the yeast used for the ethanol fermentation. C1 Univ British Columbia, Dept Wood Sci, Chair Forest Prod Biotechnol, Vancouver, BC V6T 1Z4, Canada. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Boussaid, A (reprint author), Fac Sci Semlalia, Microbiol Lab, POB 2390, Marrakech, Morocco. RI Saddler, Jack (John)/A-9103-2013 NR 21 TC 25 Z9 25 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD SEP-OCT PY 2001 VL 17 IS 5 BP 887 EP 892 DI 10.1021/bp010092b PG 6 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA 480QK UT WOS:000171473300015 PM 11587580 ER PT J AU de Jong, K Emerson, RK Butler, J Bastacky, J Mohandas, N Kuypers, FA AF de Jong, K Emerson, RK Butler, J Bastacky, J Mohandas, N Kuypers, FA TI Short survival of phosphatidylserine-exposing red blood cells in murine sickle cell anemia SO BLOOD LA English DT Article ID MEMBRANE PHOSPHOLIPID ASYMMETRY; GENERAL FEATURE; DISEASE; ERYTHROPOIESIS; ERYTHROCYTES; PHAGOCYTOSIS; MACROPHAGES; THALASSEMIA; EXPRESSION; HEMOGLOBIN AB Several transgenic murine models for sickle cell anemia have been developed that closely reproduce the biochemical and physiological disorders in the human disease. A comprehensive characterization Is described of hematologic parameters of mature red blood cells, reticulocytes, and red cell precursors in the bone marrow and spleen of a murine sickle cell model in which erythroid cells expressed exclusively human alpha, gamma, and beta (s) globin. Red cell survival was dramatically decreased in these anemic animals, partially compensated by considerable enhancement in erythropoietic activity. As in humans, these murine sickle cells contain a subpopulation of phosphatidylserine-exposing cells that may play a role in their premature removal. Continuous in vivo generation of this phosphatidylserine-exposing subset may have a significant impact on the pathophysiology of sickle cell disease. (C) 2001 by The American Society of Hematology. C1 Childrens Hosp, Oakland Res Inst, Oakland, CA 94609 USA. Lawrence Berkeley natl Lab, Berkeley, CA USA. RP Kuypers, FA (reprint author), Childrens Hosp, Oakland Res Inst, 5700 Martin Luther King Jr Way, Oakland, CA 94609 USA. FU NHLBI NIH HHS [HL20985, HL31579, HL66355]; NIDDK NIH HHS [DK32094] NR 27 TC 87 Z9 87 U1 0 U2 1 PU AMER SOC HEMATOLOGY PI WASHINGTON PA 1900 M STREET. NW SUITE 200, WASHINGTON, DC 20036 USA SN 0006-4971 J9 BLOOD JI Blood PD SEP 1 PY 2001 VL 98 IS 5 BP 1577 EP 1584 DI 10.1182/blood.V98.5.1577 PG 8 WC Hematology SC Hematology GA 467DH UT WOS:000170685000042 PM 11520810 ER PT J AU Todd, JA Crawley, D Geissler, S Lindsey, G AF Todd, JA Crawley, D Geissler, S Lindsey, G TI Comparative assessment of environmental performance tools and the role of the Green Building Challenge SO BUILDING RESEARCH AND INFORMATION LA English DT Article DE building assessment systems; building performance; environmental assessment; environmental assessment methods; 'green' buildings; Green Building Challenge; international collaboration; knowledge transfer; trends AB Green Building Challenge (GBC) was intended to advance the state-of-the-art of building performance assessment, through the development, testing, and discussion of an assessment framework, criteria and tool. The contributions of GBC to building performance assessment are considered through comparing similarities and differences with a selection of available assessment tools. Unlike national or proprietary assessment systems, GBC was not designed for application to specific commercial markets. Instead, it emphasized research and involved researchers and practitioners from many countries. Consequently, GBC has been in a unique position to test and adopt new ideas and implement step changes. GBC's roles over the past five years have been to provide a reference framework, method and tools that can be used to develop new systems or improve existing systems; provide a forum for discussion among researchers and practitioners worldwide; and raise awareness and credibility of assessment systems. GBC's role has evolved as the context in which it operates has changed. Based on the analysis on GBC's specific characteristics and strengths, its potential future roles are found to reside in a unique position. Its role as a reference system has become less important to many participants as they implement their own national assessment systems. However, GBC's role as a forum and catalyst for change has taken on greater importance as researchers and practitioners continue to wrestle with the most difficult issues in building performance assessment. C1 Sci Consulting Grp Inc, Cabin John, MD 20818 USA. US DOE, Off Bldg Syst, Washington, DC 20585 USA. Austrian Inst Appl Ecol, A-1070 Vienna, Austria. Design Harmony, Wake Forest, NC 27587 USA. RP Todd, JA (reprint author), Sci Consulting Grp Inc, 14 Webb Rd, Cabin John, MD 20818 USA. NR 18 TC 73 Z9 74 U1 3 U2 18 PU E & FN SPON PI LONDON PA 2-6 BOUNDARY ROW, LONDON SE1 8HN, ENGLAND SN 0961-3218 J9 BUILD RES INF JI Build. Res. Informat. PD SEP PY 2001 VL 29 IS 5 BP 324 EP 335 PG 12 WC Construction & Building Technology SC Construction & Building Technology GA 468PW UT WOS:000170767600002 ER PT J AU Risk, MJ Heikoop, JM Edinger, EN Erdmann, MV AF Risk, MJ Heikoop, JM Edinger, EN Erdmann, MV TI The assessment 'toolbox': Community-based reef evaluation methods coupled with geochemical techniques to identify sources of stress SO BULLETIN OF MARINE SCIENCE LA English DT Article; Proceedings Paper CT International Conference on Scientific Aspects of Coral Reef Assessment Monitoring and Restoration CY APR 14-16, 1999 CL FT LAUDERDALE, FLORIDA ID GREAT-BARRIER-REEF; CONTINENTAL-SHELF TRENDS; INDONESIAN CORAL-REEFS; STATES VIRGIN-ISLANDS; MAJOR OIL-SPILL; MONTASTREA-ANNULARIS; ISOTOPIC COMPOSITION; SOUTH THAILAND; PORITES-LUTEA; COSTA-RICA AB There have been few seminal advances in techniques of health evaluation of coral reefs since line transects and visual fish counting were first proposed in 1972, yet the rate of resource destruction increases rapidly. Especially in Third World settings, coastal communities need access to simple techniques that have been shown to identify stress on reefs: (1) Coral mortality indices, (2) Benthic bioindicators (stomatopods, forams, amphipods), (3) Coral associate counts, and (4) Bioerosion amounts in coral rubble. Coral growth rates are an undependable measure of reef health: corals on dying reefs with low coral cover often exhibit higher than normal growth rates. Transect data may be cast into other forms. such as triangular diagrams, to be more effective in reef management. All of these rapid assessment techniques have been shown to be effective in the hands of persons with limited technical training. Each is rapid and cost-effective. Once one of the 'tools' in the assessment 'toolbox' has detected stress, the precise nature of the source can be identified via geochemical techniques; (1) Sewage: stable isotope ratios of nitrogen (delta N-15) in a number of organisms (stomatopods. corals) are enriched at sites subject to sewage discharge, (2) Siltation: in areas subject to siliciclastic input. insoluble residues in coral skeletons are a measure of exogenous sediment input. (3) Thermal/Light stress: as has been shown in studies of El Nino events and the Indonesian 'haze' of 1997, the delta C-13 signal in coral skeletons is a measure of metabolic stress caused by changes in light and temperature. C1 McMaster Univ, Sch Geog & Geol, Hamilton, ON L8S 4M1, Canada. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. St Francis Xavier Univ, Dept Geol, Antigonish, NS B2G 1C0, Canada. Univ Calif Berkeley, Dept Integrat Biol, Berkeley, CA 94720 USA. RP Risk, MJ (reprint author), McMaster Univ, Sch Geog & Geol, Hamilton, ON L8S 4M1, Canada. RI Heikoop, Jeffrey/C-1163-2011 NR 74 TC 31 Z9 36 U1 2 U2 11 PU ROSENSTIEL SCH MAR ATMOS SCI PI MIAMI PA 4600 RICKENBACKER CAUSEWAY, MIAMI, FL 33149 USA SN 0007-4977 J9 B MAR SCI JI Bull. Mar. Sci. PD SEP PY 2001 VL 69 IS 2 BP 443 EP 458 PG 16 WC Marine & Freshwater Biology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 500CU UT WOS:000172609000017 ER PT J AU Maerli, MB AF Maerli, MB TI The navy says: Hands off my stash SO BULLETIN OF THE ATOMIC SCIENTISTS LA English DT Editorial Material C1 Norwegian Inst Int Affairs, Oslo, Norway. Sandia Natl Labs, Livermore, CA 94550 USA. Stanford Univ, Ctr Int Secur & Cooperat, CISAC, Stanford, CA 94305 USA. RP Maerli, MB (reprint author), Norwegian Inst Int Affairs, Oslo, Norway. NR 0 TC 0 Z9 0 U1 0 U2 0 PU EDUC FOUNDATION NUCLEAR SCI PI CHICAGO PA 6042 SOUTH KIMBARK, CHICAGO, IL 60637 USA SN 0096-3402 J9 B ATOM SCI JI Bull. Atom. Scient. PD SEP-OCT PY 2001 VL 57 IS 5 BP 24 EP 25 PG 2 WC International Relations; Social Issues SC International Relations; Social Issues GA 466QA UT WOS:000170655200016 ER PT J AU Kaufman, L Turchi, PEA Huang, WM Liu, ZK AF Kaufman, L Turchi, PEA Huang, WM Liu, ZK TI Thermodynamics of the Cr-Ta-W system by combining the ab initio and CALPHAD methods SO CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY LA English DT Article ID ORDER-ORDER TRANSFORMATIONS; BINARY-ALLOYS; BCC LATTICE; MODEL; DISORDER; ENERGY AB The thermodynamic properties of alloys can be described from the knowledge of the underlying lattice and the atomic numbers of the alloy species by using a first-principles electronic structure approach based on the tight-binding linear muffin-tin orbital method within the coherent potential approximation (TB-LMTO-CPA) and the local density approximation of density functional theory. The generalized perturbation method (GPM) permits direct mapping of the configurational part of the effective one-electron Hamiltonian onto an Ising-like model thus insuring the necessary link between quantum mechanics and statistical thermodynamics. To test the practical application of this approach to multi-component alloys, data assessment has been successfully performed for the Cr-Ta-W alloy system by using the thermodynamic results derived from the TB-LMTO-CPA-GPM and the cluster variation method (CVM) in the tetrahedron approximation for Ta-W alloys as functions of temperature and concentration. These later results predict B2 ordering for the bcc-based Ta-W system with a maximum ordering temperature near 1000 K at 43 at.% Ta. The output thermodynamics were converted to a Redlich-Kister/Bragg-Williams format with an acceptable level of accuracy. The results were then combined with those of the CALPHAD description of the Cr-W and Cr-Ta systems to calculate isothermal sections of the ternary phase diagram of the Cr-Ta-W system. (C) 2002 Published by Elsevier Science Ltd. C1 MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Univ Calif Lawrence Livermore Natl Lab L353, Livermore, CA 94551 USA. Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RP Kaufman, L (reprint author), MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. RI Liu, Zi-Kui/A-8196-2009 OI Liu, Zi-Kui/0000-0003-3346-3696 NR 31 TC 35 Z9 39 U1 4 U2 31 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0364-5916 J9 CALPHAD JI Calphad-Comput. Coupling Ph. Diagrams Thermochem. PD SEP PY 2001 VL 25 IS 3 BP 419 EP 433 AR PII S0364-5916(01)00061-X DI 10.1016/S0364-5916(01)00061-X PG 15 WC Thermodynamics; Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Thermodynamics; Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 522MW UT WOS:000173902000009 ER PT J AU Lamport, DTA AF Lamport, DTA TI Life behind cell walls: paradigm lost, paradigm regained SO CELLULAR AND MOLECULAR LIFE SCIENCES LA English DT Review DE cell wall protein; extensin; HRGPs; hydroxyproline-rich glycoprotein; arabinogalactan protein; cell extension; expansin; hydroxyproline glycosylation ID HYDROXYPROLINE-RICH GLYCOPROTEIN; SURFACE ARABINOGALACTAN-PROTEINS; TISSUE-SPECIFIC EXPRESSION; OXIDATIVE CROSS-LINKING; GUM-ARABIC GLYCOPROTEIN; HYDROGEN-FLUORIDE VAPOR; SOYBEAN ROOT-NODULES; AUXIN-INDUCED GROWTH; ALGA VOLVOX-CARTERI; EXTA EXTENSIN GENE AB This review of the living cell wall [1] and its protein components is in two parts. The first is anecdotal. A personal account spanning over 40 years research may perhaps be an antidote to one stereotypical view of scientists as detached and humorless. The second part deals with the meaning of function, particularly as it applies to hydroxyproline-rich glycoproteins. Function is a difficult word to define objectively. However, with help from such luminaries as Humpty Dumpty: "A word means what I want it to mean, neither more nor less," and Wittgenstein: "Giving examples of usage... is the only way to talk about meaning," it is possible to construct a ziggurat representing increasingly complex levels of organization from molecular structure to ecology. Forty years ago I suggested that hydroxyproline-rich structural proteins played a key role in cell wall functioning. But because the bulk of the wall is carbohydrate, there has been an understandable resistance to paradigm change. Expansins, paradoxically, contribute greatly to this resistance because their modus operandi as cell-wall-loosening proteins is based on the idea that they break hydrogen bonds between polysaccharide chains allowing slippage. However, this view is not consistent with the recent discovery [Grobe et al. (1999) Eur. J. Biochem 263: 33-40] that beta -expansins may be proteases, as it implies that the extensin network is not a straightjacket but a substrate for expansin in muro. Such a direct role for extensins in both negative and positive regulation of cell expansion and elongation may constitute a major morphogenetic mechanism operating at all levels of plant growth and development. C1 Michigan State Univ, MSU DOE Plant Res Lab, E Lansing, MI 48823 USA. RP Lamport, DTA (reprint author), Univ Sussex, Sch Biol Sci, Brighton BN1 9QG, E Sussex, England. NR 338 TC 26 Z9 27 U1 0 U2 9 PU BIRKHAUSER VERLAG AG PI BASEL PA VIADUKSTRASSE 40-44, PO BOX 133, CH-4010 BASEL, SWITZERLAND SN 1420-682X J9 CELL MOL LIFE SCI JI Cell. Mol. Life Sci. PD SEP PY 2001 VL 58 IS 10 BP 1363 EP 1385 DI 10.1007/PL00000782 PG 23 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 484ZK UT WOS:000171725600002 PM 11693520 ER PT J AU Berman, GP James, DFV Kamenev, DI AF Berman, GP James, DFV Kamenev, DI TI Stability of the ground state of a harmonic oscillator in a monochromatic wave SO CHAOS LA English DT Article ID PAUL TRAP; CYCLOTRON-RESONANCE; DEGENERATE SYSTEM; QUANTUM CHAOS; 2 PARTICLES; ION CLOUD AB The stability of the ground state of a harmonic oscillator in a monochromatic wave is studied. This model describes, in particular, the dynamics of a cold ion in a linear ion trap, interacting with two laser fields with close frequencies. The stability of the "classical ground state"-the vicinity of the point (x=0,p=0)-is analyzed analytically and numerically. For the quantum case, a method for studying a stability of the quantum ground state is developed, based on the quasienergy representation. It is demonstrated that stability of the ground state may be substantially improved by increasing the resonance number, l, where l=Omega/omega+delta, Omega and omega are, respectively, the wave frequency and the oscillator frequency, l=1,2,..., \ delta \ <1; or by detuning the system from exact resonance, so that delta not equal0. The influence of a large-amplitude wave (in the presence of chaos) on the stability of the ground state is analyzed for different parameters of the model in both the quantum and classical cases. (C) 2001 American Institute of Physics. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, CNLS, Los Alamos, NM 87545 USA. RP Berman, GP (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI James, Daniel/B-9805-2009 OI James, Daniel/0000-0003-3981-4602 NR 21 TC 0 Z9 0 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 1054-1500 J9 CHAOS JI Chaos PD SEP PY 2001 VL 11 IS 3 BP 449 EP 463 DI 10.1063/1.1383786 PG 15 WC Mathematics, Applied; Physics, Mathematical SC Mathematics; Physics GA 469EC UT WOS:000170800800003 ER PT J AU Davis, SN Cecil, LD Zreda, M Moysey, S AF Davis, SN Cecil, LD Zreda, M Moysey, S TI Chlorine-36, bromide, and the origin of spring water SO CHEMICAL GEOLOGY LA English DT Article DE radionuclides; groundwater; springs; hydrochemistry AB Natural ratios of chlorine-36 (Cl-36) to stable chlorine (i.e.. Cl-36/Cl X 10(-15)) vary in shallow groundwater of the United States from about 50 in coastal areas to about 1400 in the northern Rocky Mountains. Ratios lower than these indicate the presence of chloride (Cl-) that has been isolated from the atmosphere for hundreds of thousands of years, if not longer. Higher ratios, which can exceed 5000, usually originate from fallout from testing thermonuclear devices in the western Pacific in the 1950s. Natural mass ratios of chloride to bromide (Cl-/Br-) in precipitation vary in the United States from about 250 in coastal areas to about 50 in the north-central states. Lower ratios may suggest contamination from human sources. Higher ratios, which may exceed 2000, commonly reflect the dissolution of halite. Seawater has a Cl-/Br- ratio of 290. Both (36) Cl and Cl-/Br- ratios have been measured in 21 samples of spring water collected from springs in 10 different states. Brackish water from Saratoga Springs area in New York has low values for both Cl-36 and Cl-/Br- ratios. This indicates that a large component of the water has a very deep origin. Brackish water from Alexander Springs in Florida has a low Cl-36 ratio but a high Cl-/Br- ratio similar to seawater. This suggests the addition of ancient seawater that may be trapped in the aquifer. Big Spring in Iowa discharges water with a very high Cl-/Br- ratio but a moderate C-36, ratio. The high ratio of Cl-/Br- may be produced by dissolution of road salt or agricultural chemicals. Of the 21 springs sampled, only 10 appeared to have potable water not significantly affected by human activity. Chlorine-36 from testing of nuclear devices is still being flushed out of four of the spring systems that were sampled. Thus, more than 45 years have passed since Cl-36 was introduced into the aquifers feeding the springs and the systems, as yet, have not been purged. Published by Elsevier Science B.V. C1 Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. US Geol Survey, INEEL Ice Core Project, Idaho Falls, ID 83402 USA. Stanford Univ, Dept Geophys, Stanford, CA 94305 USA. RP Davis, SN (reprint author), Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. RI Moysey, Stephen/H-4658-2012 NR 40 TC 59 Z9 60 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD SEP 1 PY 2001 VL 179 IS 1-4 BP 3 EP 16 DI 10.1016/S0009-2541(01)00312-6 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 459LD UT WOS:000170251100002 ER PT J AU Rademacher, LK Clark, JF Hudson, GB Erman, DC Erman, NA AF Rademacher, LK Clark, JF Hudson, GB Erman, DC Erman, NA TI Chemical evolution of shallow groundwater as recorded by springs, Sagehen basin; Nevada County, California SO CHEMICAL GEOLOGY LA English DT Article DE weathering; groundwater tracers; catchment hydrodynamics; Sierra Nevada-CA ID MODELING STREAMWATER CHEMISTRY; DATING YOUNG GROUNDWATER; SOILWATER END-MEMBERS; WATER-FLOW PATHS; SIERRA-NEVADA; MASS-BALANCE; ATMOSPHERIC DEPOSITION; COASTAL-PLAIN; CHLOROFLUOROCARBONS; CATCHMENT AB Springs in Sagehen basin, California, were used to document the effect of chemical weathering on the chemical evolution and composition of groundwater in a high elevation catchment. Geochemical tracer ages were determined with chlorofluorocarbons (CFCs) and tritium/(3) He dating techniques. The spring water ages range from less than 5 years to almost 40 years. Mass balance calculations performed by NETPATH were combined with spring water ages to calculate chemical weathering rates observed throughout the basin, which range from 0.0116 to 0.0018 and from 0.0036 to 0,0006 mmol l(-1) year(-1), for plagioclase and hornblende, respectively. Major cation concentrations, pH, and spring water conductivity were found to correlate positively (R-2 = 0.7) with spring water age. This suggests that shallow groundwater, as represented by the springs, is a chemically evolving system. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Santa Barbara, Dept Geol Sci, Santa Barbara, CA 93106 USA. Lawrence Livermore Natl Lab, Analyt & Nucl Chem Div, Livermore, CA 94550 USA. Univ Calif Davis, Dept Wildlife Fish & Conservat Biol, Davis, CA 95616 USA. RP Rademacher, LK (reprint author), Univ Calif Santa Barbara, Dept Geol Sci, Santa Barbara, CA 93106 USA. NR 46 TC 50 Z9 52 U1 3 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD SEP 1 PY 2001 VL 179 IS 1-4 BP 37 EP 51 DI 10.1016/S0009-2541(01)00314-X PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 459LD UT WOS:000170251100004 ER PT J AU Demadis, KD Hartshorn, CM Meyer, TJ AF Demadis, KD Hartshorn, CM Meyer, TJ TI The localized-to-delocalized transition in mixed-valence chemistry SO CHEMICAL REVIEWS LA English DT Review ID ELECTRON-TRANSFER REACTIONS; CREUTZ-TAUBE ION; MLCT EXCITED-STATES; INFRARED-ABSORPTION INTENSITIES; VIBRONIC COUPLING MODEL; ENERGY-GAP LAW; RESONANCE RAMAN-SPECTROSCOPY; INTERVALENCE CHARGE-TRANSFER; DONOR-ACCEPTOR INTERACTIONS; DIFFERENT OXIDATION-STATES C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ N Carolina, Dept Chem, Venable Lab, Chapel Hill, NC 27599 USA. Univ N Carolina, Dept Chem, Kenan Lab, Chapel Hill, NC 27599 USA. RP Los Alamos Natl Lab, POB 1663,MS A127, Los Alamos, NM 87545 USA. EM hartshorn@cbmse.nrl.navy.mil; tjmeyer@lanl.gov RI Demadis, Kostas/A-7347-2010 NR 310 TC 671 Z9 671 U1 15 U2 133 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0009-2665 EI 1520-6890 J9 CHEM REV JI Chem. Rev. PD SEP PY 2001 VL 101 IS 9 BP 2655 EP 2685 DI 10.1021/cr990413m PG 31 WC Chemistry, Multidisciplinary SC Chemistry GA 473MB UT WOS:000171047000003 PM 11749392 ER PT J AU Fuentes, O Wang, HH Ward, BH Zhang, JH Proserpio, DM Calvagna, F Check, CE Lobring, KC Zheng, C AF Fuentes, O Wang, HH Ward, BH Zhang, JH Proserpio, DM Calvagna, F Check, CE Lobring, KC Zheng, C TI Synthesis, structural analysis, and superconductivity of BaxV6S8 SO CHEMISTRY OF MATERIALS LA English DT Article ID ELECTRICAL-PROPERTIES; TRANSITIONS; DIFFRACTION; PHASES; NB3S4 AB A nonstoichiometric ternary vanadium sulfide, BaxV6S8 (x = 0.41-0.48), was synthesized. This solid-state compound crystallizes in the hexagonal space group P6(3)/m (no. 176) with a = 9.2080(3) Angstrom, c = 3.3169(2) Angstrom, V = 243.55(2) Angstrom (3), and Z = 1. The structure of this solid is similar to that of its parent compound V3S4, consisting of face-sharing, distorted octahedral VS6 units. A superconducting transition of the solid at approximately 2.5 K was observed. A computational analysis of the electronic structure using the extended Huckel method is presented. C1 No Illinois Univ, Dept Chem & Biochem, De Kalb, IL 60115 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Milan, Dipartimento Chim Strutturale & Stereochim Inorga, I-20133 Milan, Italy. RP Zheng, C (reprint author), No Illinois Univ, Dept Chem, De Kalb, IL 60115 USA. RI Proserpio, Davide/C-6391-2009 OI Proserpio, Davide/0000-0001-6597-9406 NR 25 TC 1 Z9 1 U1 1 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD SEP PY 2001 VL 13 IS 9 BP 3051 EP 3056 DI 10.1021/cm000396d PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 474JW UT WOS:000171104200047 ER PT J AU Pennington, DW AF Pennington, DW TI An evaluation of chemical persistence screening approaches SO CHEMOSPHERE LA English DT Article DE overall persistence; chemical screening; persistent organic pollutants; POPs; PBTs; uncertainty ID GENERAL LIMITING LAW; ORGANIC-COMPOUNDS; ENVIRONMENT; DECAY; RANGE AB A chemical's ability to persist in the environment is an important criterion in determining whether concern is warranted. Screening is commonly conducted based on the maximum degradation half-life of the chemical in any given medium (air, water, soil and sediment), or in terms of model-based estimates of the chemical's overall persistence (half-life or residence time) in the environment. In practice, however, both approaches are hindered by the limited availability of degradation data. Straightforward guidelines are therefore proposed in this paper to help predetermine which half-lives are likely to be pertinent, irrespective of the screening approach adopted. The guidelines are based on partitioning coefficients (Henry's Law constant and the octanol-water partitioning coefficient). The values selected for use in the guidelines result in a quantifiable trade-off between data acquisition requirements and uncertainty. Initial screening can be performed with whatever data is readily available. Overall persistence predictions will be conservative. False-negatives are not generated. The guideline values can then be adjusted iteratively to facilitate step-wise or tiered screening. Using this iterative approach in national and international screening initiatives will result in significant time and money savings. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 US EPA, ORISE, Syst Anal Branch, NRMRL, Cincinnati, OH 45220 USA. RP Pennington, DW (reprint author), US EPA, ORISE, Syst Anal Branch, NRMRL, Cincinnati, OH 45220 USA. NR 23 TC 15 Z9 16 U1 1 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD SEP PY 2001 VL 44 IS 7 BP 1589 EP 1601 DI 10.1016/S0045-6535(00)00530-0 PG 13 WC Environmental Sciences SC Environmental Sciences & Ecology GA 466EE UT WOS:000170630700008 PM 11545525 ER PT J AU Pennington, DW AF Pennington, DW TI Relationship of approaches and a tiered methodology for screening chemicals in the context of long-range transport SO CHEMOSPHERE LA English DT Article DE long-range transport (LRT); chemical screening; uncertainty ID PERSISTENT ORGANIC POLLUTANTS; MULTIMEDIA ENVIRONMENT; GENERAL FORMULATION AB In many national and international initiatives, where thousands of chemicals are screened, the ability of a chemical to be transported over long distances is an important criterion in determining whether environmental concern is warranted. Preliminary screening can be conducted using: (1) effective travel distance (ETD); (2) characteristic travel distance (CTD); and/or (3) the degradation half-life in air. The CTD is the distance traveled before the concentration of a chemical in air is reduced by a factor of 50%, for example. Differences in the distance traveled associated with the environmental release medium of a chemical are taken into account the ETD measure. The ETD can be defined as the distance traveled before the concentration in a stated medium (air, water, soil or sediment) is reduced to a specified level for a given mass release rate to air, to water and/or to soil. However, despite their merits, the use of multimedia screening measures like the ETD and CTD remains inhibited by both the limited availability of degradation data (particularly for soils and sediments) and release pattern information. Preliminary screening in terms of the atmospheric degradation half-life is commonly the only practical option. In this paper, straightforward guidelines based on partitioning coefficients (Henry's law constant and octanol-water partitioning coefficient) are proposed to reduce the degradation data requirements of multimedia measures like the ETD and CTD. The values used in the guidelines reflect a quantifiable trade-off between data acquisition requirements and uncertainty. The relationship of the potential screening options (using all degradation data versus using only data identified as required in the CTD and ETD approaches; screening in terms of the degradation half-life in air versus the CTD versus the ETD) is derived and the consequences of the differences are illustrated. A three-tiered screening methodology is then proposed. This tiered methodology will result in significant savings in time and money in national and international screening initiatives. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 US EPA, ORISE, Syst Anal Branch, NRMRL, Cincinnati, OH 45220 USA. RP Pennington, DW (reprint author), US EPA, ORISE, Syst Anal Branch, NRMRL, Cincinnati, OH 45220 USA. NR 18 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0045-6535 J9 CHEMOSPHERE JI Chemosphere PD SEP PY 2001 VL 44 IS 7 BP 1617 EP 1631 DI 10.1016/S0045-6535(00)00529-4 PG 15 WC Environmental Sciences SC Environmental Sciences & Ecology GA 466EE UT WOS:000170630700010 PM 11545527 ER PT J AU Bova, SW Breshears, CP Gabb, H Kuhn, B Magro, B Eigenmann, R Gaertner, G Salvini, S Scott, H AF Bova, SW Breshears, CP Gabb, H Kuhn, B Magro, B Eigenmann, R Gaertner, G Salvini, S Scott, H TI Parallel programming with message passing and directives SO COMPUTING IN SCIENCE & ENGINEERING LA English DT Article ID MOLECULAR ELECTRONIC-STRUCTURE AB The authors discuss methods for expressing and tuning the performance of parallel programs, using two programming models in the same program: distributed and shared memory. Such methods are important for anyone who uses these large machines for parallel programs as well as for those who study combinations of the two programming models. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. KAI Software, Champaign, IL 61820 USA. Purdue Univ, Sch Elect & Comp Engn, W Lafayette, IN 47907 USA. Numer Algorithms Grp Ltd, Oxford OX2 8DR, England. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Bova, SW (reprint author), Sandia Natl Labs, POB 5800,MS 0835, Albuquerque, NM 87185 USA. OI Gabb, Henry/0000-0002-9507-4250 NR 12 TC 8 Z9 9 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 USA SN 1521-9615 J9 COMPUT SCI ENG JI Comput. Sci. Eng. PD SEP-OCT PY 2001 VL 3 IS 5 BP 22 EP 37 DI 10.1109/5992.947105 PG 16 WC Computer Science, Interdisciplinary Applications SC Computer Science GA 466UW UT WOS:000170665400005 ER PT J AU Link, JM AF Link, JM TI Tampolines for embedded embryoss SO DR DOBBS JOURNAL LA English DT Article AB Minimizing interrupt handlers latency. C1 Argonne Natl Lab, Argonne, IL 60439 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU MILLER FREEMAN, INC PI SAN FRANCISCO PA 600 HARRISON ST,, SAN FRANCISCO, CA 94107 USA SN 1044-789X J9 DR DOBBS J JI Dr. Dobbs J. PD SEP PY 2001 VL 26 IS 9 BP 81 EP + PG 5 WC Computer Science, Software Engineering SC Computer Science GA 457ZY UT WOS:000170169900022 ER PT J AU Li, X Yan, Y Mason, A Gessert, TA Coutts, TJ AF Li, X Yan, Y Mason, A Gessert, TA Coutts, TJ TI High mobility CdO films and their dependence on structure SO ELECTROCHEMICAL AND SOLID STATE LETTERS LA English DT Article ID THIN-FILMS; OXIDE AB The, properties of high-quality CdO films formed by low-pressure chemical vapor deposition are reported for the first time. The relationships between deposition parameters, thin-film formation, and material properties are investigated. CdO films are formed between 100 and 450 degreesC, using a dimethylcadmium precursor and oxygen gas. The CdO structure, composition, and the optical and electrical properties of the films are sensitive to the deposition temperature. A carrier concentration of 1.93 X 10(21) cm(-3), which may be introduced by structure defect, was achieved on the film deposited at a temperature of 100 degreesC. A Hall mobility of 216 cm(2) V-1 s(-1) was achieved at deposition temperature of 450 degreesC with carrier concentration of 2.35 X 10(19) cm(-3). The mobilities are much higher than those reported for CdO films made by other techniques. (C) 2001 The Electrochemical Society. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Coutts, TJ (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 16 TC 16 Z9 16 U1 0 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 65 SOUTH MAIN STREET, PENNINGTON, NJ 08534 USA SN 1099-0062 J9 ELECTROCHEM SOLID ST JI Electrochem. Solid State Lett. PD SEP PY 2001 VL 4 IS 9 BP C66 EP C68 DI 10.1149/1.1389876 PG 3 WC Electrochemistry; Materials Science, Multidisciplinary SC Electrochemistry; Materials Science GA 462MZ UT WOS:000170425000007 ER PT J AU Dahl, JK Tamburini, J Weimer, AW Lewandowski, A Pitts, R Bingham, C AF Dahl, JK Tamburini, J Weimer, AW Lewandowski, A Pitts, R Bingham, C TI Solar-thermal processing of methane to produce hydrogen and syngas SO ENERGY & FUELS LA English DT Article ID NATURAL-GAS; CO2 EMISSION; FOSSIL-FUEL; TECHNOLOGIES; ENERGY AB A solar-thermal aerosol flow reactor has been constructed, installed, and tested with the High-Flux Solar Furnace (HFSF) at the National Renewable Energy Laboratory (NREL). Experiments were successfully carried out for the dissociation of methane to produce hydrogen and carbon black and for the dry reforming of methane with carbon dioxide to form syngas (hydrogen and carbon monoxide). Approximately 90% dissociation of methane was achieved in a 25-mm diameter quartz reaction tube illuminated with a solar flux of 2400 kW/m(2) (or suns). The carbon black produced was amorphous and had a particle size of 20 to 40 nm. Approximately 70% conversion was achieved for dry reforming using a solar flux of 2000 kW/m(2). The experimental results for both processes are very encouraging and support further work to address the technical issues and to develop the processes. C1 Univ Colorado, Dept Chem Engn, Boulder, CO 80309 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Weimer, AW (reprint author), Univ Colorado, Dept Chem Engn, Boulder, CO 80309 USA. NR 21 TC 30 Z9 31 U1 3 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 2001 VL 15 IS 5 BP 1227 EP 1232 DI 10.1021/ef0100606 PG 6 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 477TH UT WOS:000171300000033 ER PT J AU Brown, AL Dayton, DC Nimlos, MR Daily, JW AF Brown, AL Dayton, DC Nimlos, MR Daily, JW TI Design and characterization of an entrained flow reactor for the study of biomass pyrolysis chemistry at high heating rates SO ENERGY & FUELS LA English DT Article ID KRAFT BLACK LIQUOR; MOLECULAR CHARACTERIZATION; CELLULOSE PYROLYSIS; MASS-SPECTROMETRY; COAL; TEMPERATURE; KINETICS; DEVOLATILIZATION; COMBUSTION; MODEL AB A laminar entrained flow reactor has been designed for studying the chemistry of fast biomass pyrolysis. This is the first of two papers on the reaction system. Peak heating rates in the reactor are on the order of 10(4) K/s. The reactor is capable of interfacing with a molecular beam mass spectrometer for rapid analysis of gas phase chemistry. Computational fluid dynamic simulations are used to predict an accurate time-temperature profile for the reactants and to better understand the internal processes in the reactor. Predicted and measured reaction rates compare favorably for a gas phase reaction standard. Particle devolatilization is modeled to help understand the tradeoff between heat transport and kinetic control of the pyrolysis rate. Biomass and cellulose particles below about 50 mum are expected to be sufficiently small to avoid heat transport pyrolysis control, and thus allow study of kinetically controlled pyrolysis in this reactor. This paper is the first of two, and describes the characterization of the entrained flow reactor and methodologies developed for determining quantitative kinetic measurements. The second paper describes the application of these techniques to the study of cellulose pyrolysis at high heating rates. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Colorado, Dept Mech Engn, Ctr Combust & Environm Res, Boulder, CO 80309 USA. RP Dayton, DC (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd,MS 3322, Golden, CO 80401 USA. NR 35 TC 41 Z9 47 U1 1 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 2001 VL 15 IS 5 BP 1276 EP 1285 DI 10.1021/ef010083k PG 10 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 477TH UT WOS:000171300000039 ER PT J AU Brown, AL Dayton, DC Daily, JW AF Brown, AL Dayton, DC Daily, JW TI A study of cellulose pyrolysis chemistry and global kinetics at high heating rates SO ENERGY & FUELS LA English DT Article ID LOW FEED RATES; BIOMASS PYROLYSIS; DECOMPOSITION KINETICS; FLASH PYROLYSIS; MODEL; TEMPERATURE; COMBUSTION; PRESSURE; WOOD AB Cellulose pyrolysis has been studied in a laminar entrained flow reactor (LEFR). As described in the previous companion paper, the reactor is capable of high heating rates (similar to 10(4) K/s) and has been characterized in detail to ensure that pyrolysis of lignocellulosic materials occurs under kinetic control at the conditions of the reactor. The extent of cellulose pyrolysis in the LEFR was monitored by sampling the gas phase products with a molecular beam mass spectrometer system, and independently by sampling and weighing residues on a filter paper. Varying the reactor furnace temperature controls the pyrolysis severity. Quantitative cellulose pyrolysis data have been compared to several published reaction rates. Published models that involve low activation energy rates from other high temperature experiments described in the literature best approximate the results obtained in this study. Factor analysis of the mass spectral data requires two principal components to interpret the gas phase product composition. This suggests that the primary cellulose pyrolysis products were involved in subsequent secondary reactions that directly compete with the primary release of products at the conditions in this reactor. A rate is presented that describes the observed thermal destruction of primary pyrolysis products. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. Univ Colorado, Dept Mech Engn, Ctr Combust & Environm Res, Boulder, CO 80309 USA. RP Dayton, DC (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd,MS 3322, Golden, CO 80401 USA. NR 47 TC 32 Z9 33 U1 0 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD SEP-OCT PY 2001 VL 15 IS 5 BP 1286 EP 1294 DI 10.1021/ef010084c PG 9 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA 477TH UT WOS:000171300000040 ER PT J AU McKinley, JP Zeissler, CJ Zachara, JM Serne, RJ Lindstrom, RM Schaef, HT Orr, RD AF McKinley, JP Zeissler, CJ Zachara, JM Serne, RJ Lindstrom, RM Schaef, HT Orr, RD TI Distribution and retention of Cs-137 in sediments at the Hanford Site, Washington SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SOLID/LIQUID DISTRIBUTION COEFFICIENTS; CESIUM SORPTION; CLAY-MINERALS; ILLITE; RADIOCESIUM; PREDICTION; SOILS; REVERSIBILITY; ADSORPTION; PARTICLES AB (137)Cesium and other contaminants have leaked from single-shell storage tanks (SSTs) into coarse-textured, relatively unweathered unconsolidated sediments. Contaminated sediments were retrieved from beneath a leaky SST to investigate the distribution of adsorbed Cs-137(+) across different sediment size fractions, All fractions contained mica (biotite, muscovite, vermiculatized biotite), quartz, and plagioclase along with smectite and kaolinite in the clay-size fraction. A phosphor-plate autoradiograph method was used to identify particular sediment particles responsible for retaining Cs-137(+). The Cs-bearing particles were found to be individual mica flakes or agglomerated, smectite, mica, quartz, and plagioclase. Of these, only the micaceous component was capable of sorbing Cs+ strongly. Sorbed Cs-137(+) could not be significantly removed from sediments by leaching with dithionite citrate buffer or KOH, but a fraction of the sorbed Cs-137(+) (5-22%) was desorbable with solutions containing an excess of Rb+. The small amount of Cs-137(+) that might be mobilized by migrating fluids in the future would likely sorb to nearby micaceous clasts in downgradient sediments. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. RP McKinley, JP (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 42 TC 65 Z9 66 U1 5 U2 28 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 SEP 1 PY 2001 VL 35 IS 17 BP 3433 EP 3441 DI 10.1021/es0018116 PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA 469PP UT WOS:000170824300016 PM 11563643 ER PT J AU McMaster, ME Jardine, JJ Ankley, GT Benson, WH Greeley, MS Gross, TS Guillette, LJ MacLatchy, DL Orlando, EF Van der Kraak, GJ Munkittrick, KR AF McMaster, ME Jardine, JJ Ankley, GT Benson, WH Greeley, MS Gross, TS Guillette, LJ MacLatchy, DL Orlando, EF Van der Kraak, GJ Munkittrick, KR TI An interlaboratory study on the use of steroid hormones in examining endocrine disruption SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE steroid hormones; interlaboratory study; endocrine disruption; pulp mill effluent; radioimmunoassay variability ID KRAFT PULP-MILL; O-DEETHYLASE ACTIVITY; WHITE SUCKER; EFFLUENT; FISH; WILDLIFE; EXPOSURE; GROWTH; STRESS AB In recent years, there has been an increased use of the measurement of sex steroid hormone levels in the blood of animals exposed to chemicals as an indicator of reproductive impairment or an alteration in endocrine function. Although levels of hormones are often compared among animals and laboratories, there has been no study to examine the between-lab oratory variability in actual steroid measurements. Therefore, we initiated a study with white sucker collected from a site receiving pulp mill effluent, previously documented as having reduced steroid levels, to address this issue. Samples of plasma and media from in vitro gonadal incubations were delivered to eight outside laboratories with the ability to measure steroid hormones. These laboratories ran-ed from well-established fish endocrine laboratories to wildlife toxicology laboratories, which have recently implemented the methods to measure steroid hormones. In this study, we have considered both the absolute measure of steroid content between laboratories as well as the ability to discriminate between reference and exposed populations as important criteria when evaluating the utility of these measures. Of the eight outside laboratories conducting the analyses, six detected identical site differences in circulating levels of testosterone and 17 beta -estradiol to those documented by our Burlington laboratory (ON, Canada). However, the absolute value of the steroid hormones measured in the plasma varied significantly (plasma testosterone 0.6-23.1 ng/ml, 17 beta -estradiol 77.6-1782.7 pg/ml) with coefficients of variation of 70.4% and 60.3% respectively. Similar results were demonstrated for the measurement of steroid hormones in media following in vitro gonadal incubation. Although there was a fair amount of variability in the absolute measure of steroid hormone levels, we would predict a far greater coherence of interlaboratory results through the sharing of reagents and the use of a common methodology between laboratories. These results are very promising, providing evidence for the inclusion of steroid hormones in monitoring endocrine disruption in wildlife species. C1 Environm Canada, Canada Ctr Inland Waters, Natl Water Res Inst, Aquat Ecosyst Protect Res Branch, Burlington, ON L7R 4A6, Canada. US EPA, Duluth, MN 55804 USA. Univ Mississippi, University, MS 38677 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. US Geol Survey, Gainesville, FL 32653 USA. Univ Florida, Gainesville, FL 32611 USA. Univ New Brunswick, St John, NB E2L 4L5, Canada. Univ Guelph, Guelph, ON N1G 2W1, Canada. Univ New Brunswick, Environm Canada, Fredericton, NB E3B 5A3, Canada. RP McMaster, ME (reprint author), Environm Canada, Canada Ctr Inland Waters, Natl Water Res Inst, Aquat Ecosyst Protect Res Branch, 867 Lakeshore Rd POB 5050, Burlington, ON L7R 4A6, Canada. RI Munkittrick, Kelly/B-1462-2014; Greeley, Mark/D-2330-2016 OI Greeley, Mark/0000-0002-6088-5942 NR 26 TC 16 Z9 18 U1 0 U2 15 PU SETAC PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3367 USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD SEP PY 2001 VL 20 IS 9 BP 2081 EP 2087 DI 10.1897/1551-5028(2001)020<2081:AISOTU>2.0.CO;2 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA 465RF UT WOS:000170603200030 PM 11521838 ER PT J AU Lo, HC Chen, H Fish, RH AF Lo, HC Chen, H Fish, RH TI Synthesis of a [{mono-N-(4-vinylbenzyl)-1,4,7-triazacyclononane}(2)Hg](OTf)(2) sandwich complex, polymerization of this monomer with divinylbenzene, and Hg2+ ion selectivity studies with the demetallated resin SO EUROPEAN JOURNAL OF INORGANIC CHEMISTRY LA English DT Article DE template synthesis; mercury; cations; sandwich complexes; polymers ID METAL-ION; EXCHANGE RESINS; POLYMERS; TEMPLATES; MATRIX AB We have synthesized a novel, 1,4,7-triazacyclononane (TACK)-Hg2+ sandwich monomer, [{mono-N-(4-vinylbenzyl)-1,4,7-TACN}(2)Hg](OTf)(2), which was co-polymerized with the cross-linking agent divinylbenzene to form a Hg2+-ion templated polymer that was demetallated (> 96%) with 6 N HCl, and subsequently found to be highly selective to reintroduced Hg2+ ions in competition with Cd2+, Ag+, Pb2+, Cu2+, and Fe3+ ions at pH 2, the ionic radius and the thermodynamic parameter being more critical than imprinting. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Fish, RH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 21 TC 5 Z9 5 U1 0 U2 1 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 1434-1948 J9 EUR J INORG CHEM JI Eur. J. Inorg. Chem. PD SEP PY 2001 IS 9 BP 2217 EP 2220 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 468HR UT WOS:000170752500005 ER PT J AU Young, CG Gable, RW Hill, JP George, GN AF Young, CG Gable, RW Hill, JP George, GN TI Mononuclear thiomolybdenyl complexes - Synthesis and structural and spectroscopic characterization SO EUROPEAN JOURNAL OF INORGANIC CHEMISTRY LA English DT Article DE molybdenum; sulfur; thiomolybdenyl complexes; EPR spectroscopy; X-ray absorption spectroscopy ID NUCLEOPHILE TRANSFER-REACTIONS; HYPERFINE COUPLING-CONSTANTS; OXYGEN-ATOM TRANSFER; OXO-MOLYBDENUM(V) COMPLEXES; OXOMOLYBDENUM(V) COMPLEXES; MOLYBDENUM HYDROXYLASES; ELECTRONIC-PROPERTIES; MOLECULAR-STRUCTURE; OXYHALIDE ANIONS; G-VALUES AB The first series of mononuclear thiomolybdenyl complexes, Tp(.)Mo(V)SX(2) [Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate, X/X-2 = anion/dianion], has been prepared. The complexes, which have been characterized by analytical, mass spectrometric, spectroscopic and X-ray crystallographic studies, provide insights into the electronic nature and chemistry of the catalytically and biologically important thiomolybdenyl unit. C1 Univ Melbourne, Sch Chem, Melbourne, Vic 3010, Australia. Stanford Synchrotron Radiat Lab, SLAC, Stanford, CA 94309 USA. RP Young, CG (reprint author), Univ Melbourne, Sch Chem, Melbourne, Vic 3010, Australia. RI George, Graham/E-3290-2013 NR 33 TC 14 Z9 14 U1 0 U2 3 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 1434-1948 J9 EUR J INORG CHEM JI Eur. J. Inorg. Chem. PD SEP PY 2001 IS 9 BP 2227 EP 2231 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 468HR UT WOS:000170752500007 ER PT J AU Schmidt, KA Bergstrom, M Hagemann, GB Herskind, B Sletten, G Varmette, PG Domscheit, J Hubel, H Odegard, SW Frattini, S Bracco, A Million, B Carpenter, MP Janssens, RVF Khoo, TL Lauritsen, T Lister, CJ Siem, S Wiedenhover, I Hartley, DJ Riedinger, LL Maj, A Ma, WC Terry, R AF Schmidt, KA Bergstrom, M Hagemann, GB Herskind, B Sletten, G Varmette, PG Domscheit, J Hubel, H Odegard, SW Frattini, S Bracco, A Million, B Carpenter, MP Janssens, RVF Khoo, TL Lauritsen, T Lister, CJ Siem, S Wiedenhover, I Hartley, DJ Riedinger, LL Maj, A Ma, WC Terry, R TI Study of Hf-169 at high rotational frequency SO EUROPEAN PHYSICAL JOURNAL A LA English DT Article ID HIGH-SPIN; NUCLEI; BANDS; ALIGNMENT AB High-spin properties, of the nucleus Hf-169 have been studied through the fusion evaporation reaction Zr-96(Ge-76,3n)Hf-169 at a beam energy of 310 MeV. The known rotational bands have been extended considerably and 6 new bands have been established, four of which form coupled bands with pronounced M1 connections. Quasiparticle assignments are suggested for the new band structures, and it appears that coupling to vibrational degrees of freedom plays a. role. Both coupled bands involve the excitation of quasiprotons. In the region of highest spin, a large alignment gain is interpreted in terms of a mixed crossing where an h(9/2) and an h(11/2) quasiproton provide the two signatures of the aligning configuration. C1 Niels Bohr Inst, DK-2100 Copenhagen O, Denmark. Univ Bonn, Inst Strahlen & Kernphys, D-53115 Bonn, Germany. Univ Oslo, Dept Phys, N-0316 Oslo, Norway. Univ Milan, Dipartimento Fis, I-20122 Milan, Italy. INFN Milano, Milan, Italy. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. H Niewodniczanski Inst Nucl Phys, PL-31342 Krakow, Poland. Mississippi State Univ, Mississippi State, MS 39762 USA. RP Schmidt, KA (reprint author), Niels Bohr Inst, Blegdamsvej 17, DK-2100 Copenhagen O, Denmark. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 17 TC 18 Z9 18 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6001 J9 EUR PHYS J A JI Eur. Phys. J. A PD SEP PY 2001 VL 12 IS 1 BP 15 EP 28 DI 10.1007/s100500170035 PG 14 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA 499JV UT WOS:000172568800004 ER PT J AU Haffner, S Schmidt, M Benning, PJ Olson, CG Miller, LL Lynch, DW AF Haffner, S Schmidt, M Benning, PJ Olson, CG Miller, LL Lynch, DW TI Strong impact of the electron-photon matrix element on angle-resolved photoelectron spectra of Sr2CuO2Cl2 SO EUROPEAN PHYSICAL JOURNAL B LA English DT Article ID FERMI-SURFACE; NORMAL-STATE; PHOTOEMISSION SPECTRUM; HOLE; GAP; BI2SR2CACU2O8+DELTA; SUPERCONDUCTORS; LEVEL; PLANE; YBA2CU3O6.9 AB In recent years insight has been gained into the electronic structure of layered cuprates using angle-resolved photoelectron spectroscopy. In many of these studies it is assumed that the electron-photon matrix element follows the trends set by the atomic photoionization cross sections and does not influence lineshape, dispersion and the k-dependence of the spectral intensity. In this study using Sr2CuO2Cl2 as an example it will be shown that the electron-photon matrix element can have a strong impact on both strength and shape of a feature in an angle-resolved photoelectron spectrum of a layered cuprate which can strongly affect information on character and the momentum-dependence of the energy and spectral weight of a state deduced from the spectra. The results of this study put an emphasis on the need to employ the whole parameter range of the ARPES method to get reliable information on the spectral function of cuprates for which purpose synchrotron radiation is an uniquely suited tool. C1 Iowa State Univ, Dept Phys & Astron, US Dept Energy, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, US Dept Energy, Ames, IA 50011 USA. RP Haffner, S (reprint author), Iowa State Univ, Dept Phys & Astron, US Dept Energy, Ames, IA 50011 USA. NR 29 TC 1 Z9 1 U1 0 U2 1 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6028 J9 EUR PHYS J B JI Eur. Phys. J. B PD SEP PY 2001 VL 23 IS 1 BP 69 EP 77 DI 10.1007/s100510170083 PG 9 WC Physics, Condensed Matter SC Physics GA 483WY UT WOS:000171659900007 ER PT J AU Page, PR AF Page, PR TI Filter for strangeness in J(PC) exotic four-quark states SO EUROPEAN PHYSICAL JOURNAL C LA English DT Article ID MESONS AB Symmetrization selection rules for the decay of four-quark states to two J = 0 mesons are analysed in a non - field theoretic context with isospin symmetry. The OZI allowed decay of an isoscalar J(PC) = {1, 3, ...}(-+) exotic state to eta' eta or f(0)'f(0) is only allowed for four quark components of the state containing one ss pair, providing a filter for strangeness content in these states. Decays of four-quark a(0) states are narrower than otherwise expected, If the experimentally observed 1(-+) enhancement in eta pi, is resonant, it is qualitatively in agreement with being a four-quark state. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Page, PR (reprint author), Los Alamos Natl Lab, Div Theoret, MS B283, Los Alamos, NM 87545 USA. RI Page, Philip/L-1885-2015 OI Page, Philip/0000-0002-2201-6703 NR 17 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6044 J9 EUR PHYS J C JI Eur. Phys. J. C PD SEP PY 2001 VL 22 IS 1 BP 165 EP 170 DI 10.1007/s100520100785 PG 6 WC Physics, Particles & Fields SC Physics GA 506VL UT WOS:000172992400016 ER PT J AU Erwin, MM Kadavanich, AV McBride, J Kippeny, T Pennycook, S Rosenthal, SJ AF Erwin, MM Kadavanich, AV McBride, J Kippeny, T Pennycook, S Rosenthal, SJ TI Material characterization of a nanocrystal based photovoltaic device SO EUROPEAN PHYSICAL JOURNAL D LA English DT Article; Proceedings Paper CT 10th International Symposium on Small Particles and Inorganic Clusters (ISSPIC 10) CY OCT 11-15, 2000 CL ATLANTA, GEORGIA SP Georgia Inst Technol, USAF, Off Sci Res ID CHARGE SEPARATION; KINETICS AB Nanocomposites have shown promise as the active layer for photovoltaic energy conversion. One example is tilt, CdSe nanocrystal\polymer composite demonstrated by Hyunh and Greenham [1, 2]. In this paper we investigate the baseline properties of the materials used in such a device. We present surface chemical information for CdSe nanocrystals and chemical analysis for poly-(3-hexylthiophene) (P3HT) polymer. C1 Vanderbilt Univ, Dept Chem, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Erwin, MM (reprint author), Vanderbilt Univ, Dept Chem, Box 1583, Nashville, TN 37235 USA. RI McBride, James/D-2934-2012 OI McBride, James/0000-0003-0161-7283 NR 13 TC 12 Z9 12 U1 0 U2 2 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1434-6060 J9 EUR PHYS J D JI Eur. Phys. J. D PD SEP PY 2001 VL 16 IS 1-3 BP 275 EP 277 DI 10.1007/s100530170109 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 490FH UT WOS:000172039400063 ER PT J AU Hastings, MB Halsey, TC AF Hastings, MB Halsey, TC TI High-dimensional diffusive growth SO EUROPHYSICS LETTERS LA English DT Article ID LIMITED AGGREGATION; BRANCHED GROWTH; FRACTAL GROWTH; FLUCTUATIONS AB We consider a model of aggregation, both diffusion-limited and ballistic, based on the Cayley tree. Growth is from the leaves of the tree towards the root, leading to nontrivial screening and branch competition effects. The model exhibits a phase transition between ballistic and diffusion-controlled growth, with non-trivial corrections to cluster size at the critical point. Even in the ballistic regime, cluster scaling is controlled by rare events due to the branching structure of the Cayley tree; it is this that enables us to solve the model. C1 Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. ExxonMobil Res & Engn, Corp Strateg Res, Annandale, NJ 08801 USA. RP Hastings, MB (reprint author), Los Alamos Natl Lab, Ctr Nonlinear Studies, MS B258, Los Alamos, NM 87545 USA. NR 20 TC 2 Z9 2 U1 0 U2 2 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD SEP PY 2001 VL 55 IS 5 BP 679 EP 685 DI 10.1209/epl/i2001-00469-9 PG 7 WC Physics, Multidisciplinary SC Physics GA 466KJ UT WOS:000170644500013 ER PT J AU Zheludev, A Honda, Z Katsumata, K Feyerherm, R Prokes, K AF Zheludev, A Honda, Z Katsumata, K Feyerherm, R Prokes, K TI Field-induced commensurate long-range order in the Haldane-gap system Ni(C5H14N2)(2)N-3 SO EUROPHYSICS LETTERS LA English DT Article ID DIMENSIONAL HEISENBERG-ANTIFERROMAGNET; MAGNETIC-FIELD; CHAIN; TEMPERATURE; RESONANCE; AZIDO; NENP AB High-field neutron diffraction studies of the new quantum-disordered S=1 linear-chain antiferromagnet Ni(C5H14N2)(2)N-3(ClO4) (NDMAZ) are reported. At T=70 mK, at a critical field H-c = 13.4 T applied along the [013] direction, a phase transition to a commensurate Neel-like ordered state is observed. The results are discussed in the context of existing theories of quantum phase transitions in Haldane-gap antiferromagnets, and in comparison with previous studies of the related system Ni(C5H14N2)(2)N-3(PF6) (NDMAP). C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RIKEN, Inst Phys & Chem Res, Wako, Saitama 3510198, Japan. Hahn Meitner Inst Berlin GmbH, D-14109 Berlin, Germany. RP Zheludev, A (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Feyerherm, Ralf/F-5487-2013 OI Feyerherm, Ralf/0000-0003-3034-4210 NR 29 TC 15 Z9 15 U1 0 U2 1 PU E D P SCIENCES PI LES ULIS CEDEXA PA 7, AVE DU HOGGAR, PARC D ACTIVITES COURTABOEUF, BP 112, F-91944 LES ULIS CEDEXA, FRANCE SN 0295-5075 J9 EUROPHYS LETT JI Europhys. Lett. PD SEP PY 2001 VL 55 IS 6 BP 868 EP 873 DI 10.1209/epl/i2001-00362-7 PG 6 WC Physics, Multidisciplinary SC Physics GA 474CJ UT WOS:000171086500018 ER PT J AU Cada, GF AF Cada, GF TI The development of advanced hydroelectric turbines to improve fish passage survival SO FISHERIES LA English DT Article AB Recent efforts to improve the survival of hydroelectric turbine-passed juvenile fish have explored modifications to both operation and design of the turbines. Much of this research is being carried out by power producers in the Columbia River basin (U.S. Army Corps of Engineers and the public utility districts), while the development of low-impact turbines is being pursued on a national scale by the U.S. Department of Energy. Fisheries managers are involved in all aspects of these efforts. Advanced versions of conventional Kaplan turbines are being installed and tested in the Columbia River basin, and a pilot scale version of a novel turbine concept is undergoing laboratory testing. Field studies in the last few years have shown that improvements in the design of conventional turbines have increased the survival of juvenile fish. There is still much to be learned about the causes and extent of injuries in the turbine system (including the draft tube and tailrace), as well as the significance of indirect mortality and the effects of turbine passage on adult fish. However, improvements in turbine design and operation, as well as new field, laboratory, and modeling techniques to assess turbine-passage survival, are contributing toward resolution of the downstream fish passage issue at hydroelectric power plants. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Cada, GF (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 26 TC 74 Z9 76 U1 5 U2 31 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 USA SN 0363-2415 J9 FISHERIES JI Fisheries PD SEP PY 2001 VL 26 IS 9 BP 14 EP 23 DI 10.1577/1548-8446(2001)026<0014:TDOAHT>2.0.CO;2 PG 10 WC Fisheries SC Fisheries GA 467XV UT WOS:000170729800003 ER PT J AU Ashurst, WT AF Ashurst, WT TI Comments on Molecular cavity flow by Donald Greenspan SO FLUID DYNAMICS RESEARCH LA English DT Editorial Material ID DYNAMICS AB Molecular mechanics simulations of liquid water in a shear-driven cavity flow have been presented by Greenspan [Fluid Dyn. Res. 25 (1999) 37]. The selected parameter values in these calculations require cautionary comments, for example, the presented turbulent flow results involve atomic motion with a kinetic temperature exceeding a million degrees Kelvin! (C) 2001 Published by The Japan Society of Fluid Mechanics and Elsevier Science B.V. All rights reserved. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Ashurst, WT (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-5983 J9 FLUID DYN RES JI Fluid Dyn. Res. PD SEP PY 2001 VL 29 IS 3 BP 221 EP 223 DI 10.1016/S0169-5983(00)00038-1 PG 3 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA 474BA UT WOS:000171083400004 ER PT J AU Hitchens, R AF Hitchens, R TI Virtual problems SO FOREIGN AFFAIRS LA English DT Letter C1 US DOE, Washington, DC 20585 USA. RP Hitchens, R (reprint author), US DOE, Washington, DC 20585 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU COUNC FOREIGN RELAT INC PI NEW YORK PA 58 E 68TH ST, NEW YORK, NY 10021 USA SN 0015-7120 J9 FOREIGN AFF JI Foreign Aff. PD SEP-OCT PY 2001 VL 80 IS 5 BP 180 EP 181 DI 10.2307/20050318 PG 2 WC International Relations SC International Relations GA 463ZC UT WOS:000170506300019 ER PT J AU Allain, LR Askari, M Stokes, DL Vo-Dinh, T AF Allain, LR Askari, M Stokes, DL Vo-Dinh, T TI Microarray sampling-platform fabrication using bubble-jet technology for a biochip system SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article ID LUNG-CANCER; FHIT; DNA; EXPRESSION; ESOPHAGUS; LESIONS AB The fabrication of microarrays containing PCR-amplified genomic DNA extracts from mice tumors on a Zetaprobe membrane using a modified thermal ink-jet printer is described. A simple and cost-effective procedure for the fabrication of microarrays containing biological samples using a modified bubble-jet printing system is presented. Because of their mass-produced design, inkjet printers are a much cheaper alternative to conventional spotting techniques. The usefulness of the biochip microarray platform is illustrated by the detection of human fragile histidine triad (FHIT), a tumor suppressor gene. Subcutaneous carcinomas were induced with MKN/FHIT and MKN/E4 cell lines in immunodeficient mice. Several weeks into their development, the tumors from both groups of mice were removed and subjected to DNA extraction by lysis of tissue samples. The extracted DNA samples were amplified by PCR (30 cycles) using the primers corresponding to nucleotides 2 to 18 of the FHIT sequence. The resulting solution was transferred to the individual reservoirs of a three-color cartridge from a conventional thermal ink-jet printer (HP 694C), and arrays were printed on to a Zetaprobe membrane. After spotting, these membranes were used in a hybridization assay, using fluorescent probes, and detected with a biochip. C1 Oak Ridge Natl Lab, Div Life Sci, Adv Monitoring Dev Grp, Oak Ridge, TN 37831 USA. RP Vo-Dinh, T (reprint author), Oak Ridge Natl Lab, Div Life Sci, Adv Monitoring Dev Grp, POB 2008, Oak Ridge, TN 37831 USA. NR 20 TC 50 Z9 52 U1 5 U2 20 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0937-0633 J9 FRESEN J ANAL CHEM JI Fresenius J. Anal. Chem. PD SEP PY 2001 VL 371 IS 2 BP 146 EP 150 DI 10.1007/s002160100962 PG 5 WC Chemistry, Analytical SC Chemistry GA 483UX UT WOS:000171655200009 PM 11678184 ER PT J AU Fintschenko, Y Choi, WY Ngola, SM Shepodd, TJ AF Fintschenko, Y Choi, WY Ngola, SM Shepodd, TJ TI Chip electrochromatography of polycyclic aromatic hydrocarbons on an acrylate-based UV-initiated porous polymer monolith SO FRESENIUS JOURNAL OF ANALYTICAL CHEMISTRY LA English DT Article ID MICELLAR ELECTROKINETIC CHROMATOGRAPHY; OPEN-CHANNEL ELECTROCHROMATOGRAPHY; CAPILLARY ELECTROCHROMATOGRAPHY; SEPARATION MEDIA; DISSOLVED-OXYGEN; ELECTROPHORESIS; MICROCHIP; FLUORESCENCE; PH; ELECTROLYTE AB The first rigorous evaluation of a UV-initiated porous polymer monolith (PPM) as a stationary phase for chip electrochromatography (ChEC) is described. All channels in an offset T-injector-design-chip (25-mum deep by 50-mum wide channels) were filled by capillary action with an acrylate-based PPM precursor solution and polymerized in situ using 365 nm light for several minutes. Photodefinability of the monolith cast in the channels during the polymerization process was also demonstrated by masking off the injection arms during photoinitiation. The chromatographic performance of this chip was compared with that of chips completely filled with monolith. The detection window was photodefined after polymerization using the detection laser (257 nm doubled argon ion laser) to depolymerize the detection window. A successful ChEC separation of 10 out of 13 polycyclic aromatic hydrocarbons (PAH) was performed with on-column, off-packing laser-induced fluorescence detection at 257 nm. Van Deemter plots for early-, middle-, and late-eluting compounds showed the minimum plate height to be 5 mum. The average number of theoretical plates per meter for the PAH was 200,000. Several factors contributed to irreproducible results. Oxygen was observed to dynamically quench the fluorescence of the sample over time. Improved sealing of the reservoirs solved this problem. A within-chip variability in the retention time of 2-10% RSD was observed. These results demonstrate the feasibility and reliability of the PPM as a solid reversed-phase for electroosmotic flow-driven chip-based chromatography in microscale total analysis systems. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Fintschenko, Y (reprint author), Sandia Natl Labs, POB 969,MS9671, Livermore, CA 94551 USA. NR 25 TC 48 Z9 49 U1 0 U2 14 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0937-0633 J9 FRESEN J ANAL CHEM JI Fresenius J. Anal. Chem. PD SEP PY 2001 VL 371 IS 2 BP 174 EP 181 DI 10.1007/s002160100948 PG 8 WC Chemistry, Analytical SC Chemistry GA 483UX UT WOS:000171655200013 PM 11678188 ER PT J AU Onozuka, M Alfile, JP Aubert, P Dagenais, JF Grebennikov, D Ioki, K Jones, L Koizumi, K Krylov, V Maslakowski, J Nakahira, M Nelson, B Punshon, C Roy, O Schreck, G AF Onozuka, M Alfile, JP Aubert, P Dagenais, JF Grebennikov, D Ioki, K Jones, L Koizumi, K Krylov, V Maslakowski, J Nakahira, M Nelson, B Punshon, C Roy, O Schreck, G TI Manufacturing and maintenance technologies developed for a thick-wall structure of the ITER vacuum vessel SO FUSION ENGINEERING AND DESIGN LA English DT Article DE ITER; vacuum vessel; nuclear fusion; nuclear fusion reactor; thick wall; welding; cutting; NDT AB Development of welding, cutting and non-destructive testing (NDT) techniques, and development of remotized systems have been carried out for on-site manufacturing and maintenance of the thick-wall structure of the International Thermonuclear Experimental Reactor (ITER) vacuum vessel (VV). Conventional techniques, including tungsten inert gas welding, plasma cutting, and ultrasonic inspection, have been improved and optimized for the application to thick austenitic stainless steel plates. In addition, advanced methods have been investigated, including reduced-pressure electron-beam and multi-pass neodymium-doped yttrium. aluminum garnet (NdYAG) laser welding, NdYAG laser cutting, and electro-magnetic acoustic transducer inspection, to improve cost and technical performance. Two types of remotized systems with different payloads have been investigated and one of them has been fabricated and demonstrated in field joint welding, cutting, and NDT tests on test mockups and full-scale ITER VV sector models, The progress and results of this development to date provide a high level of confidence that the manufacturing and maintenance of the ITER VV is feasible. (C) 2001 Elsevier Science B.V. All rights reserved. C1 JWS, ITER Garching, D-85748 Garching, Germany. CEA, Arcueil, France. GAER Syst, Marseille, France. Echoplus, Moscow, Russia. EFDA, Garching, Germany. Japan Atom Energy Res Inst, Tokai, Ibaraki 31911, Japan. Efremov Inst, St Petersburg, Russia. Boeing N Amer Inc, Canoga Pk, CA USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. TWI, Cambridge, England. CEA Saclay, Saclay, France. Univ Hannover, Hannover, Germany. RP Onozuka, M (reprint author), JWS, ITER Garching, Boltzmann Str 2, D-85748 Garching, Germany. NR 12 TC 14 Z9 17 U1 3 U2 10 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD SEP PY 2001 VL 55 IS 4 BP 397 EP 410 DI 10.1016/S0920-3796(01)00185-5 PG 14 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 471ZZ UT WOS:000170959700005 ER PT J AU Valenza, D Iida, H Plenteda, R Santoro, RT AF Valenza, D Iida, H Plenteda, R Santoro, RT TI Proposal of shutdown dose estimation method by Monte Carlo code SO FUSION ENGINEERING AND DESIGN LA English DT Article DE Monte Carlo code; shutdown dose estimation AB In the ITER project, the estimation of the dose equivalent rate levels after reactor shutdown for hands-on maintenance around the torus is a key point. The Sn transport and activation codes, because of their poor ability for modelling complex geometry (as in the ITER machine), yield a large uncertainty in radiation transport calculations where the geometry is not simple. In this paper, we propose a method that solves the above problem using a Monte Carlo code that allows a detailed geometry description. This new method requires modification of nuclear data library replacing a prompt gamma spectrum with a decay gamma spectrum and also a modest change in the computer program (MCNP). A simple geometry benchmark problem was conducted, comparing the new method and an existing method (THIDA-2). The agreement of the two methods is fairly good, suggesting that the new method is useful for very complex geometry devices. The slight difference observed in the results from both methods likely comes from the difference in the nuclear data library used in both methods. (C) 2001 Elsevier Science B.V. All rights reserved. C1 EURATOM Assoc, Max Planck Inst Plasmaphys, D-85748 Garching, Germany. ITER Jont Cent Team, D-85748 Garching, Germany. CTBTO, Vienna Int Ctr, A-1250 Vienna, Austria. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP Valenza, D (reprint author), EURATOM Assoc, Max Planck Inst Plasmaphys, Boltzmannstr 2, D-85748 Garching, Germany. NR 4 TC 28 Z9 30 U1 1 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD SEP PY 2001 VL 55 IS 4 BP 411 EP 418 DI 10.1016/S0920-3796(01)00188-0 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 471ZZ UT WOS:000170959700006 ER PT J AU Hollis, KJ Castro, RG Doerner, RP Maggiore, CJ AF Hollis, KJ Castro, RG Doerner, RP Maggiore, CJ TI The removal of co-deposited carbon/deuterium films from stainless steel and tungsten by transferred-arc cleaning SO FUSION ENGINEERING AND DESIGN LA English DT Article DE carbon/deuterium films; stainless steel; tungsten; transferred-arc cleaning ID HYDROGEN; EROSION; WALLS AB Deuterium and carbon were co-deposited onto tungsten and stainless steel samples using a deuterium plasma seeded with varying amounts of deuterated methane to simulate carbon-based deposited layers in magnetic-confinement fusion devices. Cathodic arc, or transferred-arc (TA) cleaning was employed to remove the deposits from the samples. The samples were characterized by ion beam analysis both before and after cleaning to determine deuterium and carbon concentrations present, The extent of TA cleaning was varied to determine the deuterium and carbon removal efficiency and sample erosion rate. The deuterium content was greatly reduced by the cleaning, thus demonstrating the possibility of using the TA cleaning technique for removing deuterium and/or tritium from components exposed to D-T fuels. The TA removal of carbon, tantalum and molybdenum contaminants from the same samples was also quantified. Removal of surface layers and significant reduction of subsurface concentrations of these contaminants were observed. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Los Alamos, NM USA. Univ Calif San Diego, La Jolla, CA 92093 USA. RP Hollis, KJ (reprint author), Mat Sci & Technol Div, MST-6,MS G-770,POB 1663, Los Alamos, NM 87545 USA. NR 15 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0920-3796 J9 FUSION ENG DES JI Fusion Eng. Des. PD SEP PY 2001 VL 55 IS 4 BP 437 EP 447 DI 10.1016/S0920-3796(01)00218-6 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 471ZZ UT WOS:000170959700008 ER PT J AU Clarke, WB Oliver, BM McKurbre, MCH Tanzella, FL Tripodi, P AF Clarke, WB Oliver, BM McKurbre, MCH Tanzella, FL Tripodi, P TI Search for He-3 and He-4 in Arata-style palladium cathodes II: Evidence for tritium production SO FUSION SCIENCE AND TECHNOLOGY LA English DT Article DE palladium cathodes; tritium; helium isotopes; mass spectrometry ID COLD FUSION REACTION; DEUTERATED PD-BLACK; HELIUM HE-4(2); ACHIEVEMENT AB Measurements have been made of He-3, He-4, and H-3 in a sample containing 2.7% of the gas from the interior of an Arata-style hollow palladium electrode charged with similar to5 g Pd-black that had undergone electrolysis in D2O as a cathode for 90 days and then as an anode for a further 83 days. There is no evidence for the much larger amounts of He-4 observed by Arata and Zhang in similar experiments. However, a very large concentration has been found of He-3, 2.3 +/- 0.5 X 10(12) atoms/cm(3) standard temperature and pressure that apparently can all be attributed to the decay of tritium produced during electrolysis. No direct production of He-3 can be specified, a result that is also different from the conclusions of Arata and Zhang. The He-3 and tritium measurements and the results of a gas analysis using a Finnigan-type mass spectrometer show that at the end of the anodic electrolysis, the electrode void contained 5.8 +/- 0.7 X 10(13) atoms tritium in the gas phase as HT, DT and T-2, and 1.7 +/- 0.3 X 10(15) atoms tritium in the aqueous phase as HTO, DTO, and T2O. At this stage, the gas phase pressure was similar to 18.8 atm in a free volume of 0.6 cm(3) and the total mass of water was similar to5.7 mg. The gas phase tritium value is viewed as a lower limit for gaseous tritium produced inside the electrode because some of that tritium must have been removed into the D2O electrolyte during the anodic episode. The He-3 and He-4 measurements were also made in the two samples of the Pd-black and in sections cut from the walls of both Pd electrodes. The H2O electrolyzed samples did not show any evidence of unusually high He-3 and/or He-4, but all the D2O electrolyzed samples showed clear evidence of He-3 from tritium decay. A stepwise temperature heating experiment performed with a 24.9-mg sample of the D2O Pd-black showed that the diffusion process for He-3 can be described by an equation of the form D = D-0 exp(-U/kT) with an activation energy U of 1.1 eV It is also apparent that the He-3 from tritium is quantitatively retained in the Pd-black at room temperature. C1 McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4K1, Canada. Pacific NW Natl Lab, Richland, WA 99352 USA. SRI Int, Energy Res Ctr, Menlo Pk, CA 94025 USA. SRI Int, Mat Res Lab, Menlo Pk, CA 94025 USA. RP Clarke, WB (reprint author), McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4K1, Canada. NR 35 TC 15 Z9 15 U1 1 U2 5 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60526 USA SN 0748-1896 J9 FUSION SCI TECHNOL JI Fusion Sci. Technol. PD SEP PY 2001 VL 40 IS 2 BP 152 EP 167 PG 16 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 462ZK UT WOS:000170452200006 ER PT J AU Kim, J Bergmann, A Wehri, E Lu, XC Stubbs, L AF Kim, J Bergmann, A Wehri, E Lu, XC Stubbs, L TI Imprinting and evolution of two Kruppel-type zinc-finger genes, ZIM3 and ZNF264, located in the PEG3/USP29 imprinted domain SO GENOMICS LA English DT Article ID BECKWITH-WIEDEMANN-SYNDROME; PROXIMAL CHROMOSOME-7; MAMMALIAN DEVELOPMENT; ANTISENSE RNA; LOCUS; PEG3; METHYLATION; TRANSCRIPTS; EXPRESSION; MECHANISM AB We have isolated Kruppel-type (C2H2) zinc-finger genes, ZIM3 (zinc-finger gene 3 from imprinted domain) and ZNF264, located downstream of human and mouse USP29 genes (encoding ubiquitin-specific processing protease 29). In human, both ZIM3 and ZNF264 encode zinc-finger proteins with Kruppel-associated box (KRAB) A and B domains at the amino-terminal regions of the predicted proteins. In contrast, mouse Zim3 and Zfp264 seem to have lost protein-coding capability based on the lack of open reading frames (ORFs) in their cDNA sequences. In particular, the 3 ' end of the Zim3 transcript overlaps with the coding region of the adjacent gene Usp29 in an antisense orientation, indicating the conversion of mouse Zim3 into an antisense transcript gene for Usp29. The expression patterns of ZIM3 and ZNF264 have been largely conserved between human and mouse, with testis-specific expression of ZIM3 and ubiquitous expression of ZNF264, but high expression levels in adult testes in both species. Our studies also demonstrate that both mouse genes are imprinted with maternal expression of Zim3 in adult testes and paternal expression of Zfp264 in neonatal and adult brain. The reciprocal imprinting of two neighboring mouse genes, Zim3 and Zfp264, is consistent with a pattern observed frequently in other imprinted domains, and suggests that the imprinting of these two genes might be coregulated. C1 Lawrence Livermore Natl Lab, Biol & Biotechnol Res Progra, Genom Div, Livermore, CA 94551 USA. DOE Joint Genome Inst, Walnut Creek, CA 94598 USA. RP Kim, J (reprint author), Lawrence Livermore Natl Lab, Biol & Biotechnol Res Progra, Genom Div, L-441,7000 E Ave, Livermore, CA 94551 USA. OI Stubbs, Lisa/0000-0002-9556-1972 NR 39 TC 33 Z9 35 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0888-7543 J9 GENOMICS JI Genomics PD SEP PY 2001 VL 77 IS 1-2 BP 91 EP 98 DI 10.1006/geno.2001.6621 PG 8 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA 469GU UT WOS:000170806800014 PM 11543637 ER PT J AU Kukkadapu, RK Zachara, JM Smith, SC Fredrickson, JK Liu, CX AF Kukkadapu, RK Zachara, JM Smith, SC Fredrickson, JK Liu, CX TI Dissimilatory bacterial reduction of Al-substituted goethite in subsurface sediments SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID CRYSTALLINE IRON(III) OXIDES; MICROBIAL REDUCTION; IRON-OXIDES; GREEN RUST; MOSSBAUER-SPECTROSCOPY; EXTRACTION TECHNIQUES; DIAGENETIC SIDERITE; DISSOLUTION; CARBONATE; FE(III) AB The microbiologic reduction of a 0.2 to 2.0 mum size fraction of an Atlantic coastal plain sediment (Eatontown) was investigated using a dissimilatory Fe(III)-reducing bacterium (Shewanella putrefaciens, strain CN32) to evaluate mineralogic controls on the rate and extent of Fe(III) reduction and the resulting distribution of biogenic Fe(II). Mossbauer spectroscopy and X-ray diffraction (XRD) were used to show that the sedimentary Fe(III) oxide was Al-substituted goethite (13-17% Al) that existed as 1- to 5-mum aggregates of indistinct morphology. Bioreduction experiments were performed in two buffers [HCO3-; 1,4-piperazinediethansulfonic acid (PIPES)] both without and with 2,6-anthraquinone disulfonate (AQDS) as an electron shuttle. The production of biogenic Fe(II) and the distribution of Al (aqueous and sorbed) were followed over time, as was the formation of Fe(II) biominerals and physical/chemical changes to the goethite. The extent of reduction was comparable in both buffers. The reducibility (rate and extent) was enhanced by AQDS; 9% of dithionite-citrate-bicarbonate (DCB) extractable Fe(III) was reduced without AQDS whereas 15% was reduced in the presence of AQDS. XRD and Mossbauer spectroscopy were used to monitor the disposition of biogenic Fe(II) and changes to the Al-goethite. Fe(II) biomineralization was not evident by XRD. Biomineralization was observed by Mossbauer when sorbed Fe(II) concentrations exceeded a threshold value. The biomineralization products displayed Mossbauer spectra consistent with siderite FeCO3 (HCO3- buffer only) and green rust [(Fe(6-x)FexIII)-Fe-II(OH)(12)](x+)[(A(2-))(x/2).yH(2)O](x-). Adsorption of biogenic Fe(II) to accessory mineral phases (e.g., kaolinite) and bacterial surfaces appeared to limit biomineralization. Al evolved during reduction was sorbed, and extractable Al increased with reduction. XRD analysis indicated that neither crystallite size or the Al content of the goethite was affected by bacterial reduction, i.e., Al release was congruent with Fe(II). Copyright (C) 2001 Elsevier Science Ltd. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Kukkadapu, RK (reprint author), Pacific NW Natl Lab, MSIN K8-96,POB 999, Richland, WA 99352 USA. RI Liu, Chongxuan/C-5580-2009 NR 52 TC 76 Z9 79 U1 1 U2 25 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD SEP PY 2001 VL 65 IS 17 BP 2913 EP 2924 DI 10.1016/S0016-7037(01)00656-1 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 472HK UT WOS:000170977900008 ER PT J AU Roback, RC Johnson, TM McLing, TL Murrell, MT Luo, SD Ku, TL AF Roback, RC Johnson, TM McLing, TL Murrell, MT Luo, SD Ku, TL TI Uranium isotopic evidence for groundwater chemical evolution and flow patterns in the eastern Snake River Plain aquifer, Idaho SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article DE flow; groundwater; Snake River plain; strontium; uranium disequilibrium ID GEOCHEMISTRY; DISSOLUTION; DIAGENESIS; TRANSPORT; SYSTEMS; RATIOS; MODEL AB The isotopic composition and concentration of uranium and strontium in groundwater, combined with solute concentration data, provide important details regarding groundwater geochemical evolution and flow-pathways in the eastern Snake River Plain aquifer. The study was conducted in the vicinity of the Idaho National Engineering and Environmental Laboratory (INEEL), Idaho, which has a long history of storing and disposing of radioactive waste, some of which has entered the aquifer. Uranium concentrations in INEEL groundwater range from 0.3 to 3.6 ppb, and U-234/U-238 atomic ratios range between 0.000085 and 0.000168 (activity ratios of 1.5 to 3.1). All of the samples have natural U-235/U-238 ratios, and U-236 was not detected; thus, the trends delineated by the U-234/U-238 ratios reflect natural variations in the aquifer. Groundwater nearest the valleys that provides focused recharge to the Snake River Plain aquifer from the northwest has high U-234/U-238 ratios when compared to values of regional groundwater flowing southwestward in the aquifer. Mixing of these water masses can account for the intermediate uranium isotope ratios of some of the samples; however, water-rock interaction must also be invoked to account for the observed trends in isotopic data. Uranium and Sr-87/Sr-86 isotope ratios are positively correlated and define a trend toward isotope ratios of the aquifer host rock. These relations indicate that dissolution and/or ion exchange are more important than alpha recoil or selective leaching in controlling U-234/U-238 ratios. As a result, U-234/U-238 ratios decrease along flow pathways toward the secular equilibrium values of the aquifer host rock. Uranium and strontium isotopic modification can be explained by incongruent dissolution of the host basalt. Lateral distributions of U-234/U-238 ratios indicate elongate zones of high U-234/U-238 ratios extending southward from the mouths of Birch Creek and the Little Lost River. These elongate zones are interpreted as preferential flow paths. Two isolated pockets of groundwater located in the central and western parts of the study area have lower U-234/U-238 ratios than the adjacent aquifer water. Both of these zones are interpreted to contain stagnant waters that are relatively isolated from flow in the regional aquifer due to lower permeability. Physical and chemical evidence strongly suggests that the stagnant zones are dominated by water from the Big Lost River that infiltrated via flood control ponds (spreading areas), playas, and the riverbed. C1 Los Alamos Natl Lab, Environm Div, Los Alamos, NM 87545 USA. Univ Illinois, Dept Geol, Urbana, IL 61801 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. Univ So Calif, Dept Earth Sci, Los Angeles, CA 90089 USA. RP Roback, RC (reprint author), Los Alamos Natl Lab, Environm Div, MS J514, Los Alamos, NM 87545 USA. RI Johnson, Thomas/A-2740-2008 OI Johnson, Thomas/0000-0003-1620-1408 NR 26 TC 22 Z9 24 U1 2 U2 7 PU ASSOC ENGINEERING GEOLOGISTS GEOLOGICAL SOCIETY AMER PI COLLEGE STN PA TEXAS A & M UNIV, DEPT GEOLOGY & GEOPHYSICS, COLLEGE STN, TX 77843-3115 USA SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD SEP PY 2001 VL 113 IS 9 BP 1133 EP 1141 DI 10.1130/0016-7606(2001)113<1133:UIEFGC>2.0.CO;2 PG 9 WC Geosciences, Multidisciplinary SC Geology GA 470GQ UT WOS:000170862900002 ER PT J AU Barnard, PL Owen, LA Sharma, MC Finkel, RC AF Barnard, PL Owen, LA Sharma, MC Finkel, RC TI Natural and human-induced landsliding in the Garhwal Himalaya of northern India SO GEOMORPHOLOGY LA English DT Article DE Himalayas; landslide; cosmogenic dating; fluvial incision; denudation ID EARTHQUAKE-INDUCED LANDSLIDES; SLOPE-FAILURE; MASS MOVEMENT; EVOLUTION AB After the March 28, 1999, Garhwal earthquake, 338 active landslides, including 56 earthquake- induced landslides, were mapped in a 226-km(2)-study area in the Garhwal Himalaya, northern India. These landslides mainly comprised shallow failures in regolith and highly weathered bedrock involving avalanches, slides, and flows. The total volume of active landslide debris in the region was estimated to be similar to1.3 million m(3) including 0.02 million m(3) (<2% of the total volume) moved during and within a few days of the earthquake. The denudation produced by the active landsliding within the study area is equivalent to a maximum landscape lowering of similar to5.7 mm. If active landsliding persists for a duration of between similar to1 and 10 years, then denudation due to landsliding is in the order of similar to0.6-6 mm a(-1). Approximately, two-thirds of the landslides in this region were initiated or accelerated by human activity, mostly by the removal of slope toes at road cuts, suggesting that human activity is accelerating denudation in this region. Three ancient catastrophic landslides, each involving >1 million m(3) of debris, were identified and two were dated to the early-middle Holocene using cosmogenic radionuclide Be-10 and Al-26. Cosmogenic radionuclide Be-10 and Al-26 were also used to date strath terraces along the Alaknanda River in lower Garhwal Himalaya to provide an estimate of similar to4 mm a(-1) for the rate of regional denudation throughout the Holocene. Natural landsliding, therefore, contributes similar to5-50% of the overall denudation in this region and is important as a formative process in shaping the landscape. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Riverside, Dept Earth Sci, Riverside, CA 92521 USA. Jawaharlal Nehru Univ, Ctr Study Reg Dev, New Delhi 110067, India. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. RP Owen, LA (reprint author), Univ Calif Riverside, Dept Earth Sci, Riverside, CA 92521 USA. NR 35 TC 95 Z9 96 U1 0 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X J9 GEOMORPHOLOGY JI Geomorphology PD SEP PY 2001 VL 40 IS 1-2 BP 21 EP 35 DI 10.1016/S0169-555X(01)00035-6 PG 15 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA 471RM UT WOS:000170942500003 ER PT J AU Lowman, JP King, SD Gable, CW AF Lowman, JP King, SD Gable, CW TI The influence of tectonic plates on mantle convection patterns, temperature and heat flow SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE convection; dynamics; heat flow; mantle; plate tectonics ID THERMAL-CONVECTION; VISCOSITY; MODELS; GENERATION; LITHOSPHERE; TOPOGRAPHY; SIMULATION; MARGINS AB The dynamic coupling between plate motion and mantle convection is investigated in a suite of Cartesian models by systematically varying aspect ratios and plate geometries. The aim of the study presented here is to determine to what extent plates affect mantle flow patterns, temperature and surface heat flux. To this end, we compare numerical convection models with free-slip boundary conditions to models that incorporate between one and six plates, where the geometries of the plates remain fixed while the plate velocities evolve dynamically with the flow. We also vary the widths of the plates and the computational domain in order to determine what constraint these parameters place on the mean temperature, heat flux and plate velocity of mantle convection models. We have investigated the influence of plates for three whole-mantle convection cases that differ in their heating modes (internally heated and basally heated) and rheologies (isoviscous and depth-dependent viscosity). We present a systematic investigation of over 30 models that exhibit increasingly complex behaviour in order to understand highly time-dependent systems using the insight gained from simpler models. In models with aspect ratios from 0.5 to 12 we find that for the same heating mode, variations in temperature can be as much as 40 per cent when comparing calculations with unit-width plates to models incorporating plates with widths equal to five times the model depth. Mean surface heat flux may decrease by 60 per cent over the same range of plate widths. We also find that internally heated mantle convection models incorporating plates exhibit novel behaviour that, we believe, has not been described previously in mantle convection studies. Specifically, in internally heated models, plate motion is characterized by episodic reversals in direction driven by changes in the mantle circulation from clockwise to counterclockwise and vice versa. These flow reversals occur in internally heated convection and are caused by a build-up of heat in the interiors of wide convection cells close to mantle downwellings. We find that flow reversals occur rapidly and are present in both single-plate and multiple-plate models that include internal heating. This behaviour offers a possible explanation for why the Pacific plate suddenly changed its direction some 43 Ma. C1 Los Alamos Natl Lab, Inst Geophys & Planetary Phys, Los Alamos, NM 87545 USA. Purdue Univ, Dept Earth & Atmospher Sci, W Lafayette, IN 47907 USA. RP Lowman, JP (reprint author), Univ Leeds, Sch Earth Sci, Leeds LS2 9JT, W Yorkshire, England. RI King, Scott/B-1220-2008; Gable, Carl/B-4689-2011; OI King, Scott/0000-0002-9564-5164; Gable, Carl/0000-0001-7063-0815 NR 37 TC 42 Z9 42 U1 0 U2 9 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD SEP PY 2001 VL 146 IS 3 BP 619 EP 636 DI 10.1046/j.1365-246X.2001.00471.x PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 474VD UT WOS:000171126800005 ER PT J AU Daley, TM Cox, D AF Daley, TM Cox, D TI Orbital vibrator seismic source for simultaneous P- and S-wave crosswell acquisition SO GEOPHYSICS LA English DT Article ID TEXAS CARBONATE RESERVOIR; ALGEBRAIC RECONSTRUCTION AB A recently developed borehole seismic source, the orbital vibrator, was successfully deployed in a cross-well survey in a fractured basalt aquifer. This seismic source uses a rotating eccentric mass to generate seismic energy. Source sweeps with clockwise and counterclockwise rotations are recorded at each source location. Because this source generates circularly polarized waves, unique processing algorithms are used to decompose the recordings into two equivalent linearly oscillating, orthogonally oriented seismic sources. The orbital vibrator therefore generates P- and S-waves simultaneously for all azimuths. A coordinate rotation based on P-wave particle motion is used to align the source components from various depths. In a field experiment, both P- and S-wave arrivals were recorded using fluid-coupled hydrophone sensors. The processed field data show clear separation of P - and S-wave arrivals for in-line and crossline source components, respectively. A tensor convolutional description of the decomposition process allows for extension to multicomponent sensors. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Conoco Inc, Ponca City, OK 74063 USA. RP Daley, TM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. RI Daley, Thomas/G-3274-2015 OI Daley, Thomas/0000-0001-9445-0843 NR 13 TC 13 Z9 13 U1 0 U2 2 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 USA SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD SEP-OCT PY 2001 VL 66 IS 5 BP 1471 EP 1480 DI 10.1190/1.1487092 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 484KC UT WOS:000171687900015 ER PT J AU Glinsky, ME Clark, GA Cheng, PKZ Devi, KRS Robinson, JH Ford, GE AF Glinsky, ME Clark, GA Cheng, PKZ Devi, KRS Robinson, JH Ford, GE TI Automatic event picking in prestack migrated gathers using a probabilistic neural network SO GEOPHYSICS LA English DT Article ID WAVE-PROPAGATION; SAMPLING THEORY AB We describe algorithms for automating the process of picking seismic events in prestack migrated common depth image gathers. The approach uses supervised learning and statistical classification algorithms along with advanced signal/image processing algorithms. No model assumption is made, such as hyperbolic moveout. We train a probabilistic neural network for voxel classification using event times, subsurface points, and offsets (ground truth information) picked manually by expert interpreters. The key to success is using effective features that capture the important behavior of the measured signals. We test a variety of features calculated in a local neighborhood about the voxel under analysis. Selection algorithms ensure that we use only the features that maximize class separability. This event-picking algorithm has the potential to reduce significantly the cycle time and cost of 3-D prestack depth migration while making the velocity model inversion more robust. C1 BHP Petr, Houston, TX 77056 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Davis, Davis, CA 95616 USA. Shell Explorat & Prod Technol Co, Bellaire Res Ctr, Houston, TX 77001 USA. RP Glinsky, ME (reprint author), BHP Petr, 1360 Post Oak Blvd,Suite 150, Houston, TX 77056 USA. NR 29 TC 4 Z9 4 U1 0 U2 1 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 USA SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD SEP-OCT PY 2001 VL 66 IS 5 BP 1488 EP 1496 DI 10.1190/1.1487094 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 484KC UT WOS:000171687900017 ER PT J AU Vesselinov, VV Neuman, SP AF Vesselinov, VV Neuman, SP TI Numerical inverse interpretation of single-hole pneumatic tests in unsaturated fractured tuff SO GROUND WATER LA English DT Article ID INJECTION TESTS; PUMPING TESTS; PERMEABILITY AB A numerical inverse method was used to interpret simultaneously multirate injection and recovery data from single-hole pneumatic tests in unsaturated fractured tuff at the Apache Leap Research Site near Superior, Arizona. Our model represents faithfully the three-dimensional geometry of boreholes at the site, and accounts directly for their storage and conductance properties by treating them as high-permeability and high-porosity cylinders of finite length and radius. It solves the airflow equations in their original nonlinear form and yields information about air permeability, air-filled porosity and dimensionless borehole storage coefficient. Some of this is difficult to accomplish with analytical type-curves. Air permeability values obtained by our inverse method agree well with those obtained by steady-state and type-curve analyses. C1 Univ Arizona, Dept Hydrol & Water Resources, Tucson, AZ 85721 USA. Los Alamos Natl Lab, Geoanal Grp, Los Alamos, NM 87545 USA. RP Vesselinov, VV (reprint author), Los Alamos Natl Lab, Hydrol Geochem & Geol Grp, POB 1663, Los Alamos, NM 87545 USA. RI Vesselinov, Velimir/P-4724-2016 OI Vesselinov, Velimir/0000-0002-6222-0530 NR 37 TC 13 Z9 13 U1 0 U2 4 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 USA SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 2001 VL 39 IS 5 BP 685 EP 695 DI 10.1111/j.1745-6584.2001.tb02358.x PG 11 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA 468YC UT WOS:000170784900007 PM 11554246 ER PT J AU Routh, J Grossman, EL Murphy, EM Benner, R AF Routh, J Grossman, EL Murphy, EM Benner, R TI Characterization and origin of dissolved organic carbon in Yegua ground water in Brazos County, Texas SO GROUND WATER LA English DT Article ID ISOTOPIC COMPOSITION; HUMIC SUBSTANCES; MATTER; SEDIMENTS; AQUIFER; RIVER; FRACTIONATION; GEOCHEMISTRY; DEGRADATION; SUBSURFACE AB Dissolved organic carbon (DOC) concentrations in five shallow (< 20 m) and three deeper wells (27 to 30 m) in the Eocene Yegua Formation (Brazos County in east-central Texas) ranged from 92 to 500 m. Characterization of high, intermediate, and low molecular weight DOC fractions (HMW > 3000 amu, IMW 1000 to 3000 amu, and LMW 500 to 1000 amu) and combined neutral sugar analyses provide information on organic matter sources in the Yegua aquifers. Combined neutral sugars ranged in concentration from 0.6 to 2.7 mu mol/L and comprised 0.8% to 6.7% of DOC in ground water. Glucose was the most abundant neutral sugar, followed by xylose and galactose, arabinose, mannose, rhamnose, and fucose. These combined neutral sugars were more diagenetically altered in shallow, oxic ground water as indicated by high mole % fucose + rhamnose and low neutral sugar yield. The precursors for neutral sugars are most probably angiosperm leaves, which show a similar distribution pattern of neutral sugars. Ground water DOC was depleted in C-13 relative to soil-zone organic matter (OM) (-16 parts per thousand to -19 parts per thousand). The delta C-13 values of bulk DOC and HMW DOC ranged from -24 parts per thousand to -32 parts per thousand, whereas LMW and MV DOC ranged from -32 parts per thousand to -34 parts per thousand and -16 parts per thousand to -28 parts per thousand, respectively. This variability in delta C-13 values is probably related to microbial processes and selective preservation of OM. Carbon isotope analyses in bulk and different molecular weight DOC fractions imply a predominantly C-3 OM source and a low contribution of soil-zone OM to DOC. C1 Texas A&M Univ, Dept Geol & Geophys, College Stn, TX 77843 USA. Pacific NW Natl Lab, Environm & Energy Sci Div, Richland, WA 99352 USA. Univ S Carolina, Dept Biol Sci, Columbia, SC 29208 USA. RP Routh, J (reprint author), Stockholm Univ, Dept Geol & Geochem, S-10691 Stockholm, Sweden. RI Benner, Ronald/M-4412-2015 OI Benner, Ronald/0000-0002-1238-2777 NR 42 TC 16 Z9 16 U1 2 U2 14 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 USA SN 0017-467X J9 GROUND WATER JI Ground Water PD SEP-OCT PY 2001 VL 39 IS 5 BP 760 EP 767 DI 10.1111/j.1745-6584.2001.tb02367.x PG 8 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA 468YC UT WOS:000170784900016 PM 11554255 ER PT J AU Crisman, SA Molz, FJ Dunn, DL Sappington, FC AF Crisman, SA Molz, FJ Dunn, DL Sappington, FC TI Application procedures for the electromagnetic borehole flowmeter in shallow unconfined aquifers SO GROUND WATER MONITORING AND REMEDIATION LA English DT Article ID IN-WELL HYDRAULICS; NUMERICAL EVALUATION; LAYERED AQUIFER; CONDUCTIVITY; ZONE AB It is increasingly common for the electromagnetic borehole flowmeter (EBF) to be used to measure hydraulic conductivity (K) distributions in subsurface flow systems. Past applications involving the EBF have been made mostly in confined aquifers (Kabala 1994: Boman et al. 1997; Podgorney and Ritzi 1997; Ruud and Kabala 1997a, 1997b; Flach et al. 2000), and it has been common to set up a flow field around a test well using a small pump that is located near the top of the well screen (Molz and Young 1993). In thin, unconfined aquifers that exhibit ground water tables near the ground surface and that undergo drawdown during pumping, such a configuration can be problematical because pumping and associated drawdown may effectively isolate the upper portion of the aquifer from the flowmeter. In these instances, a steady-state flow field in the vicinity of the test well may be created using injection rather than pumping, allowing for testing in the otherwise isolated upper portion of the aquifer located near the initial water table position. Using procedures developed by Molz and Young (1993), which were modified for an injection mode application, testing was conducted to determine whether or not the injection mode,would provide useful information in a shallow, unconfined aquifer that required the collection of data near the initial water table position. Results indicated that the injection mode for the EBF was well suited for this objective. C1 Clemson Univ, Dept Environm Engn & Sci, Anderson, SC 29625 USA. Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29808 USA. RP Crisman, SA (reprint author), Clemson Univ, Dept Environm Engn & Sci, 342 Comp Ct, Anderson, SC 29625 USA. NR 23 TC 8 Z9 8 U1 6 U2 7 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 USA SN 1069-3629 J9 GROUND WATER MONIT R JI Ground Water Monit. Remediat. PD FAL PY 2001 VL 21 IS 4 BP 96 EP 100 DI 10.1111/j.1745-6592.2001.tb00645.x PG 5 WC Water Resources SC Water Resources GA 494QW UT WOS:000172298200007 ER PT J AU Kram, ML Keller, AA Rossabi, J Everett, LG AF Kram, ML Keller, AA Rossabi, J Everett, LG TI DNAPL characterization methods and approaches, part 1: Performance comparisons SO GROUND WATER MONITORING AND REMEDIATION LA English DT Article ID DENSE CHLORINATED SOLVENTS; PARTITIONING TRACER METHOD; NONAQUEOUS PHASE LIQUIDS; SOIL; NAPL; GROUNDWATER; DISSOLUTION; AQUIFER; POOLS; WATER AB Contamination from the use of chlorinated solvents, often classified as dense nonaqueous phase liquids (DNAPLs) when in an undissolved state, represents an environmental challenge with global implications. Mass-transfer limitations due to rate-limited dissolution can lead to longterm aquifer persistence for even small volumetric fractions. The identification of DNAPL source zones located beneath the water table is critical to ultimately achieve site remediation and aquifer restoration. This paper provides a comparison of the advantages and disadvantages of many of the methods being used for detecting and delineating DNAPL contaminant source zones. The objective is to determine which options are best to pursue based on site characteristics, method performance, and method costs. DNAPL characterization methods are grouped into approaches, which include site preparation, characterization, and data-processing activities necessary to design an effective remediation system. We compare the different approaches based on the level of chemical and hydrogeologic resolution, and the need for additional data requirements. Our findings can be used to assist with selection of appropriate site remediation management options. C1 Univ Calif Santa Barbara, Bren Sch Environm Sci & Management, Santa Barbara, CA 93106 USA. Savannah River Technol Ctr, Environm Sic & Technol Div, Aiken, SC 29808 USA. Univ Calif Santa Barbara, Vadose Zone Monitoring Lab, Santa Barbara, CA 93106 USA. IT Grp Inc, Santa Barbara, CA 93106 USA. RP Kram, ML (reprint author), Univ Calif Santa Barbara, Bren Sch Environm Sci & Management, 4666 Phys Sci N, Santa Barbara, CA 93106 USA. NR 53 TC 25 Z9 25 U1 0 U2 7 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 USA SN 1069-3629 J9 GROUND WATER MONIT R JI Ground Water Monit. Remediat. PD FAL PY 2001 VL 21 IS 4 BP 109 EP 123 DI 10.1111/j.1745-6592.2001.tb00647.x PG 15 WC Water Resources SC Water Resources GA 494QW UT WOS:000172298200009 ER PT J AU McNab, WW Ruiz, R AF McNab, WW Ruiz, R TI In situ measurement of electroosmotic fluxes and conductivity using single wellbore tracer tests SO GROUND WATER MONITORING AND REMEDIATION LA English DT Article ID SOIL REMEDIATION; REMOVAL; CONTAMINANTS; TECHNOLOGY; CLAY AB Electro-osmosis (EO), the movement of water through porous media in response to an electric field, offers a means for extracting contaminated ground water from fine-grained sediments, such as clays, that are not easily amenable to conventional pump-and-treat approaches. The EO-induced water flux is proportional to the voltage gradient in a manner analogous to the flux dependence on the hydraulic gradient under Darcy's law. The proportionality constant, the sail electro-osmotic conductivity or k(eo), is most easily measured in soil cores using bench-top tests, where flow is one-dimensional and interfering effects attributable to Darcy's law can be directly accounted for. In contrast, quantification of EO fluxes and k(eo) in the field under deployment conditions can be difficult because electrodes are placed in ground water wells that may be screened across a heterogeneous mixture of lithologies. As a result, EO-induced water fluxes constitute an approximate radial flow system that is superimposed upon a Darcy flow regime through permeable pathways that may or may not be coupled with hydraulic head differences created by the EO-induced water fluxes. A single well comparative tracer test, which indirectly measures EO fluxes by comparing wellbore tracer dilution rates between background and EO-induced water fluxes, may provide a means for routinely quantifying the efficacy of EO systems in such settings. EO fluxes measured in field tests through this technique at a ground water contamination site were used to estimate a mean k(eo) value through a semianalytic line source model of the electric field. The resulting estimate agrees well with values reported in the literature and with values obtained with bench-top tests conducted on a soil core collected in the test area. C1 Exponent Failure Anal Associates, Oakland, CA 94612 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP McNab, WW (reprint author), Exponent Failure Anal Associates, 1970 Broadway,Ste 250, Oakland, CA 94612 USA. NR 18 TC 1 Z9 1 U1 0 U2 2 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 USA SN 1069-3629 J9 GROUND WATER MONIT R JI Ground Water Monit. Remediat. PD FAL PY 2001 VL 21 IS 4 BP 133 EP 139 DI 10.1111/j.1745-6592.2001.tb00649.x PG 7 WC Water Resources SC Water Resources GA 494QW UT WOS:000172298200011 ER PT J AU Rees, B Prando, P AF Rees, B Prando, P TI Documentation and log keeping: Ensuring your work does what you intend it to do SO HEALTH PHYSICS LA English DT Article DE litigation; radiation protection; public information; professional ethics AB Maintaining regular documentation, such as a logbook, can be an organization's most important asset when dealing with radiation protection issues, both normal and abnormal. When an organization is faced with litigation, proper documentation of events can ensure that a record is acceptable and, by extension, that the data itself is acceptable. A record of events will not preclude litigation, nor will it guarantee that an organization will prevail in a court of law, but it will provide evidence and credibility that could favorably affect the outcome of litigation. An organization can ensure that the documents it creates and maintains are as effective as possible by being aware of the legal consequences of documenting events and taking appropriate steps to conform to standards for admission of documentation. Misconceptions about log keeping such as recording only events that are likely to result in litigation, rather than recording all events, can prevent a record from being admissible as evidence. Because of the amount of effort and time put into documentation, and the reliance placed on its contents, it is important for an organization to ensure that a record will do what it is intended to do, namely to accurately record activities. Issues discussed in this article include the legal basis of documentary evidence, what and what not to record, when and how to record it, and how to strengthen the records kept. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rees, B (reprint author), Los Alamos Natl Lab, POB 1663,MS J 562, Los Alamos, NM 87545 USA. EM brees@lanl.gov NR 1 TC 1 Z9 1 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD SEP PY 2001 VL 81 IS 3 BP 265 EP 268 DI 10.1097/00004032-200109000-00007 PG 4 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA 462JT UT WOS:000170417500007 PM 11513459 ER PT J AU Lieuallen, K Pennacchio, LA Park, M Myers, RM Lennon, GG AF Lieuallen, K Pennacchio, LA Park, M Myers, RM Lennon, GG TI Cystatin B-deficient mice have increased expression of apoptosis and glial activation genes SO HUMAN MOLECULAR GENETICS LA English DT Article ID APOLIPOPROTEIN-D; ASTROCYTES; SCRAPIE; PROTEIN; FIBRONECTIN; EPILEPSY; DISEASE; BRAIN AB Loss-of-function mutations in the cystatin B (Cstb) gene cause a neurological disorder known as Unverricht-Lundborg disease (EPM1) in human patients. Mice that lack Cstb provide a mammalian model for EPM1 by displaying progressive ataxia and myoclonic seizures. We analyzed RNAs from brains of Cstb-deficient mice by using modified differential display, oligonucleotide microarray hybridization and quantitative reverse transcriptase polyrnerase chain reaction to examine the molecular consequences of the lack of Cstb. We identified seven genes that have consistently increased transcript levels in neurological tissues from the knockout mice. These genes are cathepsin S, C1q B-chain of complement (C1qB), beta2-microglobulin, glial fibrillary acidic protein (Gfap), apolipoprotein D, fibronectin 1 and metallothionein 11, which are expected to be involved in increased proteolysis, apoptosis and glial activation. The molecular changes in Cstb-deficient mice are consistent with the pathology found in the mouse model and may provide clues towards the identification of therapeutic points of intervention for EPM1 patients. C1 VeraGene LLC, Potomac, MD 20854 USA. Human Genome Sci, Rockville, MD 20850 USA. Lawrence Berkeley Lab, Dept Genome Sci, Berkeley, CA 94720 USA. Stanford Univ, Sch Med, Dept Genet, Stanford, CA 94305 USA. Gene Log Inc, Gaithersburg, MD 20878 USA. RP Lennon, GG (reprint author), VeraGene LLC, 9812 Falls Rd,Suite 114-237, Potomac, MD 20854 USA. EM glennon@veragene.com NR 20 TC 68 Z9 71 U1 0 U2 5 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0964-6906 J9 HUM MOL GENET JI Hum. Mol. Genet. PD SEP 1 PY 2001 VL 10 IS 18 BP 1867 EP 1871 DI 10.1093/hmg/10.18.1867 PG 5 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA 477MC UT WOS:000171286500001 PM 11555622 ER PT J AU Chow, WW Spahn, OB Schneider, HC Klem, JF AF Chow, WW Spahn, OB Schneider, HC Klem, JF TI Contributions to the large blue emission shift in a GaAsSb type-II laser SO IEEE JOURNAL OF QUANTUM ELECTRONICS LA English DT Article DE quantum-well lasers; semiconductor laser; surfacing emitting laser; type-II quantum well ID QUANTUM-WELL-LASERS; GAIN AB The large blue shift in the emission with excitation in a GaAsSb-based type-II quantum well is investigated experimentally and theoretically. Comparison of theory with experiment is made for lasers with "W" type-II structures. The analysis shows the blue shift to be the result of charge-separation, band-distortion, and many-body interactions. For a high threshold gain, there is an additional contribution from the n=2 subband transition. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Chow, WW (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Schneider, Hans Christian/B-9450-2009 OI Schneider, Hans Christian/0000-0001-7656-4919 NR 18 TC 17 Z9 17 U1 1 U2 6 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9197 J9 IEEE J QUANTUM ELECT JI IEEE J. Quantum Electron. PD SEP PY 2001 VL 37 IS 9 BP 1178 EP 1182 DI 10.1109/3.945323 PG 5 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 468HW UT WOS:000170752900010 ER PT J AU Hietala, VM Chun, C Laskar, J Choquette, KD Geib, KM Allerman, AA Hindi, JJ AF Hietala, VM Chun, C Laskar, J Choquette, KD Geib, KM Allerman, AA Hindi, JJ TI Two-dimensional 8 x 8 photoreceiver array and VCSEL drivers for high-throughput optical data links SO IEEE JOURNAL OF SOLID-STATE CIRCUITS LA English DT Article; Proceedings Paper CT 22nd IEEE GaAs IC Symposium CY NOV 05-08, 2000 CL SEATTLE, WASHINGTON SP IEEE, Electron Device Soc, IEEE Microwave Theory & Techn Soc, IEEE Solid-State Circuits Soc DE driver circuits; integrated optoelectronics; MESFET integrated circuits; optical interconnections; optical receivers; photodetectors; semiconductor laser arrays; transimpedance amplifiers ID FABRICATION; RECEIVER AB Two custom GaAs integrated circuits (ICs) have been developed for enabling vertical cavity surface emitting laser (VCSEL) arrays to be used for high throughput spatial division multiplexed (SDM) optical data links. A 16-channel driver IC was developed to drive the VCSEL array and an 8 X 8 monolithic photoreceiver, which spatially matches the VCSEL array, was developed for receive. Both of these circuits were fabricated in a standard commercial GaAs MESFET process with parasitic photodetectors used for the photoreceivers. Power dissipation and circuit size were primary design challenges for both circuits. The present 8 x 8 array size along with an estimated usable channel speed of 1 Gb/s allows for an aggregate throughput of 64 Gb/s. C1 Quellan Inc, Atlanta, GA 30318 USA. RF Solut Inc, Atlanta, GA 30318 USA. Georgia Inst Technol, Atlanta, GA 30332 USA. Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Cielo Commun, Broomfield, CO USA. RP Hietala, VM (reprint author), Quellan Inc, Atlanta, GA 30318 USA. NR 6 TC 12 Z9 12 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9200 J9 IEEE J SOLID-ST CIRC JI IEEE J. Solid-State Circuit PD SEP PY 2001 VL 36 IS 9 BP 1297 EP 1302 DI 10.1109/4.944654 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA 467RG UT WOS:000170717100002 ER PT J AU Young, EW Choquette, KD Chuang, SL Geib, KM Fischer, AJ Allerman, AA AF Young, EW Choquette, KD Chuang, SL Geib, KM Fischer, AJ Allerman, AA TI Single-transverse-mode vertical-cavity lasers under continuous and pulsed operation SO IEEE PHOTONICS TECHNOLOGY LETTERS LA English DT Article DE laser modes; modulation; vertical-cavity surface-emitting laser ID SURFACE-EMITTING LASERS; PERFORMANCE AB Using a hybrid ion implanted/selectively oxidized device structure, we report high-power single-mode operation of an 850-nm vertical-cavity laser. Under continuous-wave operation, > 4 mW of single-mode power with 45 dB of side-mode suppression is achieved. The spectral behavior under pulsed modulation is determined to be influenced by thermal lensing. When biased to threshold, single-mode operation with > 35-dB side-mode suppression is obtained for large signal modulation. C1 Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Young, EW (reprint author), Univ Illinois, Dept Elect & Comp Engn, Urbana, IL 61801 USA. NR 8 TC 82 Z9 82 U1 1 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1041-1135 J9 IEEE PHOTONIC TECH L JI IEEE Photonics Technol. Lett. PD SEP PY 2001 VL 13 IS 9 BP 927 EP 929 DI 10.1109/68.942649 PG 3 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA 466KA UT WOS:000170643700005 ER PT J AU Sheen, DM McMakin, DL Hall, TE AF Sheen, DM McMakin, DL Hall, TE TI Three-dimensional millimeter-wave imaging for concealed weapon detection SO IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES LA English DT Article DE Fourier optics; microwave holography; millimeter-wave imaging; surveillance; three-dimensional imaging; weapon detection ID SYNTHETIC APERTURE RADAR; WIDE-BAND AB Millimeter-wave imaging techniques and systems have been developed at the Pacific Northwest National Laboratory (PNNL), Richland, WA, for the detection of concealed weapons and contraband at airports and other secure locations. These techniques were derived from microwave holography techniques that utilize phase and amplitude information recorded over a two-dimensional aperture to reconstruct a focused image of the target. Millimeter-wave imaging is well suited for the detection of concealed weapons or other contraband carried on personnel since millimeter-waves are nonionizing, readily penetrate common clothing material, and are reflected from the human body and any concealed items. In this paper, a wide-bandwidth three-dimensional holographic microwave imaging technique is described. Practical weapon detection systems for airport or other high-throughput applications require high-speed scanning on the order of 3 to 10 s. To achieve this goal, a prototype imaging system utilizing a 27-33 GHz linear sequentially switched array and a high-speed linear scanner has been developed and tested. This system is described in detail along with numerous imaging results. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Sheen, DM (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 31 TC 419 Z9 442 U1 14 U2 63 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 0018-9480 J9 IEEE T MICROW THEORY JI IEEE Trans. Microw. Theory Tech. PD SEP PY 2001 VL 49 IS 9 BP 1581 EP 1592 DI 10.1109/22.942570 PG 12 WC Engineering, Electrical & Electronic SC Engineering GA 466JZ UT WOS:000170643600011 ER PT J AU Munson, TS Facchinei, F Ferris, MC Fischer, A Kanzow, C AF Munson, TS Facchinei, F Ferris, MC Fischer, A Kanzow, C TI The semismooth algorithm for large scale complementarity problems SO INFORMS JOURNAL ON COMPUTING LA English DT Article DE complementarity; large scale systems; nonsmooth analysis; iterative linear solvers ID NONMONOTONE STABILIZATION METHODS; NEWTON METHOD; EQUATIONS; OPTIMIZATION; GAMS AB Complementarity solvers are continually being challenged by modelers demanding improved reliability and scalability. Building upon a strong theoretical background, the semismooth algorithm has the potential to meet both of these requirements. We discuss relevant theory associated with the algorithm and then describe a sophisticated implementation in detail. Particular emphasis is given to the use of preconditioned iterative methods to solve the (nonsymmetric) systems of linear equations generated at each iteration and robust methods for dealing with singularity. Results on the MCPLIB test suite indicate that the code is reliable and efficient and scales well to very large problems. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Roma La Sapienza, Dipartimento Informat & Sistemist, I-00185 Rome, Italy. Univ Wisconsin, Dept Comp Sci, Madison, WI 53706 USA. Univ Dortmund, Fachbereich Math, Inst Angew Math, D-44221 Dortmund, Germany. Univ Hamburg, Fachbereich Math, Schwerpunkt Optimierung & Approximat, D-20146 Hamburg, Germany. RP Munson, TS (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Facchinei, Francisco/H-1295-2011; OI Facchinei, Francisco/0000-0002-7714-1210 NR 41 TC 27 Z9 27 U1 0 U2 1 PU INFORMS PI LINTHICUM PA 901 ELKRIDGE LANDING RD, STE 400, AIPORT SQUARE, LINTHICUM, MD 21090-2908 USA SN 1091-9856 J9 INFORMS J COMPUT JI INFORMS J. Comput. PD FAL PY 2001 VL 13 IS 4 BP 294 EP 311 DI 10.1287/ijoc.13.4.294.9734 PG 18 WC Computer Science, Interdisciplinary Applications; Operations Research & Management Science SC Computer Science; Operations Research & Management Science GA 500TK UT WOS:000172642700004 ER PT J AU Chen, KC Peterson, EJ Thoma, DJ AF Chen, KC Peterson, EJ Thoma, DJ TI HfCo2 Laves phase intermetallics - part I: solubility limits and defect mechanisms SO INTERMETALLICS LA English DT Article DE intermetallics; miscellaneous; laves phases ID POINT-DEFECTS; ALLOYS; DEFORMATION AB Solubility limits and constitutional defects in Laves phase intermetallics are investigated with the C15 HfCo2 system. Several binary alloy compositions based on HfCo2 are characterized by optical and scanning electron microscopy (SEM), electron microprobe analysis (EPMA), X-ray diffraction (XRD), and density measurements. Rietveld refinements of XRD scans are used to determine lattice constants, anisotropic strain parameters, and atomic occupancies. Compositional trends are compared against predicted or calculated trends due to an anti-site substitution or vacancy defect mechanism. Geometric models and atomic size factors are used to establish solubility limits and to give insight into defect mechanisms. Results from various, complementary experiments are consistent with anti-site substitutions on both sides of HfCo2 stoichiometry. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Chen, KC (reprint author), Calif Polytech State Univ San Luis Obispo, Dept Mat Engn, San Luis Obispo, CA 93407 USA. NR 33 TC 12 Z9 15 U1 2 U2 7 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD SEP PY 2001 VL 9 IS 9 BP 771 EP 783 DI 10.1016/S0966-9795(01)00068-1 PG 13 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 485FN UT WOS:000171743000004 ER PT J AU Chen, KC Chu, FM Kotula, PG Thoma, D AF Chen, KC Chu, FM Kotula, PG Thoma, D TI HfCo2 Laves phase intermetallics - part II: elastic and mechanical properties as a function of composition SO INTERMETALLICS LA English DT Article DE intermetallics; miscellaneous; laves phases ID DEFORMATION; TOUGHNESS; CONSTANTS; COMPOUND; NBCR2 AB In efforts to establish and understand structure-property relationships in Laves phase intermetallics, elastic and mechanical properties are studied as a function of composition in the C15 HfCo2 System. Elastic constants and Debye temperatures are determined by resonant ultrasound spectroscopy (RUS) at room temperature. A maximum near the stoichiometric Laves composition is revealed with the Young's modulus, bulk modulus, and Poisson's ratio. In addition, a slight drop in shear modulus is found with Co-rich compositions, and the Debye temperature increases with Co-content. Room temperature Vickers indentation is performed to assess the microhardness and fracture toughness of the HfCo2 alloys. A maximum in hardness occurs near the stoichiometric composition, which is contrary to the behavior displayed in most other classes of intermetallics. Slight improvements in the toughness are found with the Co-rich compositions of the Laves phase. Compositional trends of the properties are attributed to defect structures, and are analyzed with respect to the bonding of the structure and the ease in which the synchroshear deformation process proceeds. Toughening strategies and methodologies are then developed based upon these results. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Chen, KC (reprint author), Calif Polytech State Univ San Luis Obispo, Dept Mat Engn, San Luis Obispo, CA 93407 USA. EM kcchen@calpoly.edu RI Kotula, Paul/A-7657-2011 OI Kotula, Paul/0000-0002-7521-2759 NR 30 TC 12 Z9 15 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 EI 1879-0216 J9 INTERMETALLICS JI Intermetallics PD SEP PY 2001 VL 9 IS 9 BP 785 EP 798 DI 10.1016/S0966-9795(01)00067-X PG 14 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 485FN UT WOS:000171743000005 ER PT J AU Hong, SL Fu, CL AF Hong, SL Fu, CL TI Theoretical study on cracking behavior in two-phase alloys Cr-Cr2X (X = Hf, Nb, Ta, Zr) SO INTERMETALLICS LA English DT Article DE laves phase; elastic properties ID MECHANICAL-PROPERTIES; CR2NB; CR AB To examine the importance of thermal expansion mismatch on cracking in two-phase Cr-Cr2X (X = Hf, Nb, Ta, Zr) alloys, we have calculated the coefficients of thermal expansion (CTE) of Cr and Laves-phase Cr2X alloys by local-density-functional approach. A Debye model is used to approximate the phonon contribution through the elastic acoustic response. The sound velocities are determined by the calculated elastic constants and associated anharmonicity. The calculation shows that the CTE of Cr at high temperatures is notably larger than those of Cr2X. If the difference in CTE between Cr and Cr2X, is a primary source of crack initiation, our results fail to explain the experimental observation that, among these four Cr-Cr2X alloy systems, the ingot cracking is present mainly in Cr-Cr2Nb. We suggest that for the cracking to occur,the presence of thermal mismatch stresses are retained by a hard and supersaturated Cr matrix (e.g. due to the relatively high solubility of Nb in Cr in the case of Cr-Cr2Nb). On the other hand, the softer Cr matrix can accommodate thermal misfit dislocations plastically even though the CTE difference between Cr and Cr2X is large. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Hong, SL (reprint author), Sejong Univ, Dept Phys, Seoul 143747, South Korea. NR 17 TC 9 Z9 11 U1 1 U2 4 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0966-9795 J9 INTERMETALLICS JI Intermetallics PD SEP PY 2001 VL 9 IS 9 BP 799 EP 805 DI 10.1016/S0966-9795(01)00069-3 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA 485FN UT WOS:000171743000006 ER PT J AU Foster, I Kesselman, C Tuecke, S AF Foster, I Kesselman, C Tuecke, S TI The anatomy of the grid: Enabling scalable virtual organizations SO INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS LA English DT Article; Proceedings Paper CT Workshop on Clusters and Computational Grids for Scientific Computing CY SEP 25-27, 2000 CL CHATEAU FAVERGES, FRANCE SP INRIA, Natl Sci Fdn, Myricom, Microsoft Res, Compaq, Turbo Linux, Univ Tennessee, Univ Claude Bernard Lyon 1 ID INFRASTRUCTURE AB "Grid" computing has emerged as an important new field, distinguished from conventional distributed computing by its focus on large-scale resource sharing, innovative applications, and, in some cases, high performance orientation. In this article, the authors define this new field. First, they review the "Grid problem,"which is defined as flexible, secure, coordinated resource sharing among dynamic collections of individuals, institutions, and resources-what is referred to as virtual organizations. In such settings, unique authentication, authorization, resource access, resource discovery, and other challenges are encountered. It is this class of problem that is addressed by Grid technologies. Next, the authors present an extensible and open Grid architecture, in which protocols, services, application programming interfaces, and software development kits are categorized according to their roles in enabling resource sharing. The authors describe requirements that they believe any such mechanisms must satisfy and discuss the importance of defining a compact set of intergrid protocols to enable interoperability among different Grid systems. Finally, the authors discuss how Grid technologies relate to other contemporary technologies, including enterprise integration, application service provider, storage service provider, and peer-to-peer computing. They maintain that Grid concepts and technologies complement and have much to contribute to these other approaches. C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. Univ Chicago, Dept Comp Sci, Chicago, IL 60637 USA. Univ So Calif, Inst Informat Sci, Los Angeles, CA 90089 USA. RP Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave,MCS-221, Argonne, IL 60439 USA. EM foster@mcs.anl.gov RI Tavares, Antonio/A-7115-2008; Winstein, Carolee/A-8375-2008; OI Kesselman, Carl/0000-0003-0917-1562 NR 63 TC 1782 Z9 2083 U1 5 U2 64 PU SAGE PUBLICATIONS LTD PI LONDON PA 1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND SN 1094-3420 EI 1741-2846 J9 INT J HIGH PERFORM C JI Int. J. High Perform. Comput. Appl. PD FAL PY 2001 VL 15 IS 3 BP 200 EP 222 DI 10.1177/109434200101500302 PG 23 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 474ZP UT WOS:000171137400002 ER PT J AU Johnston, WE AF Johnston, WE TI Using computing and data grids for large-scale science and engineering SO INTERNATIONAL JOURNAL OF HIGH PERFORMANCE COMPUTING APPLICATIONS LA English DT Article; Proceedings Paper CT Workshop on Clusters and Computational Grids for Scientific Computing CY SEP 25-27, 2000 CL CHATEAU FAVERGES, FRANCE SP INRIA, Natl Sci Fdn, Myricom, Microsoft Res, Compaq, Turbo Linux, Univ Tennessee, Univ Claude Bernard Lyon 1 AB The term Grid is used to refer to a software system that provides uniform and location-independent access to geographically and organizationally dispersed, heterogeneous resources that are persistent and supported. These emerging data and computing Grids promise to provide a highly capable and scalable environment for addressing large-scale science problems. The author describes the requirements for science Grids, the resulting services and architecture of NASA's Information Power Grid and the Department of Energy's Science Grid, and some of the scaling issues that have come up in their implementation. C1 Lawrence Berkeley Natl Lab, Natl Energy Res Sci Comp Div, Berkeley, CA 94720 USA. NASA, Ames Res Ctr, NAS, Moffett Field, CA 94035 USA. RP Johnston, WE (reprint author), Lawrence Berkeley Natl Lab, Natl Energy Res Sci Comp Div, 1 Cyclotron Rd,MS 50B-2239, Berkeley, CA 94720 USA. NR 12 TC 4 Z9 4 U1 0 U2 0 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 USA SN 1094-3420 J9 INT J HIGH PERFORM C JI Int. J. High Perform. Comput. Appl. PD FAL PY 2001 VL 15 IS 3 BP 223 EP 242 DI 10.1177/109434200101500303 PG 20 WC Computer Science, Hardware & Architecture; Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA 474ZP UT WOS:000171137400003 ER PT J AU Yadav, S Repetto, EA Ravichandran, G Ortiz, M AF Yadav, S Repetto, EA Ravichandran, G Ortiz, M TI A computational study of the influence of thermal softening on ballistic penetration in metals SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article ID LONG-ROD PENETRATORS; SHEAR LOCALIZATION; ALUMINUM TARGETS; PERFORMANCE; SIMULATION; COMPOSITE; ENERGY; RATES AB A two-dimensional axisymmetric computational study of the penetration of a tungsten heavy alloy (WHA) rod into a 6061-T6 aluminum target has been performed using a Lagrangian formulation. Adaptive remeshing has been used to alleviate the problem of excessive distortion of elements which occurs during large deformation studies (such as ballistic penetration). Strain hardening, strain-rate hardening and thermal softening in both the penetrator and target materials are taken into full consideration. The computed depth of penetration (DOP), residual penetrator length and maximum crater diameter match very well the experimental results reported by Yadav and Ravichandran (Int. J. Impact Eng., Submitted for publication) for an impact velocity of 1100 m/s. Computer simulations reveal that in the absence of failure mechanisms (such as shear banding), introduction of thermal softening in the penetrator material decreases its depth of penetration in a metal target, when compared to a penetrator material which does not soften thermally. These results are in contrast to the recent work of Rosenberg and Dekel (Int. J. Impact Eng. 21 (1998) 283-296) and a plausible explanation for this discrepancy is presented. (C) 2001 Elsevier Science Ltd. All rights reserved. C1 CALTECH, Grad Aeronaut Labs, Pasadena, CA 91125 USA. RP Yadav, S (reprint author), Fermilab Natl Accelerator Lab, MS 316,POB 500, Batavia, IL 60510 USA. NR 25 TC 23 Z9 23 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD SEP PY 2001 VL 25 IS 8 BP 787 EP 803 DI 10.1016/S0734-743X(01)00008-2 PG 17 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA 461UT UT WOS:000170382400005 ER PT J AU Massoudi, M AF Massoudi, M TI Local non-similarity solutions for the flow of a non-Newtonian fluid over a wedge SO INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS LA English DT Article DE power-law model; non-Newtonian fluid; similar and non-similar solutions; drag reduction; fluids of differential type ID CONJUGATE HEAT-TRANSFER; BOUNDARY-LAYER FLOWS; FALKNER-SKAN FLOWS; DRAG REDUCTION; 2ND-GRADE FLUID; STAGNATION POINT; VISCOELASTIC FLUID; POROUS PLATE; 3RD GRADE; INJECTION AB The boundary layer and heat transfer equations for a non-Newtonian fluid, represented by a power-law model, over a porous wedge is studied. The free stream velocity, the surface temperature variations, and the injection velocity at the surface are assumed variables. Similar and non-similar solutions are presented and the restrictions for these cases are studied. The results are presented for velocity and temperature profiles for various values of the dimensionless numbers. The effects of the different parameters on the skin friction co-efficient and the local heat transfer co-efficient are also studied. Published by Elsevier Science Ltd. C1 US DOE, Natl Energy Technol Lab, Pittsburgh, PA 15236 USA. RP US DOE, Natl Energy Technol Lab, POB 19040, Pittsburgh, PA 15236 USA. EM massoudi@netl.doe.gov NR 51 TC 25 Z9 26 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0020-7462 EI 1878-5638 J9 INT J NONLIN MECH JI Int. J. Non-Linear Mech. PD SEP PY 2001 VL 36 IS 6 BP 961 EP 976 DI 10.1016/S0020-7462(00)00061-5 PG 16 WC Mechanics SC Mechanics GA 436EB UT WOS:000168922600008 ER PT J AU Grossman, G Zaltash, A AF Grossman, G Zaltash, A TI ABSIM - modular simulation of advanced absorption systems SO INTERNATIONAL JOURNAL OF REFRIGERATION-REVUE INTERNATIONALE DU FROID LA English DT Article DE refrigerating system; absorption system; configuration; operation; modelling; software ID HEAT-PUMP; PERFORMANCE ANALYSIS; AMMONIA-WATER; CYCLES AB The computer code ABSIM has been developed for simulation of absorption systems in a flexible and modular form, making it possible to investigate various cycle configurations with different working fluids. Based on a user-supplied cycle diagram, working fluid specification and given operating conditions, the program calculates the temperature, flowrate, concentration, pressure and vapor fraction at each state point in the system and the heat duty at each component. The modular structure of the code is based on unit subroutines containing the governing equations for the system's components. A main program calling these subroutines links the components together according to the cycle diagram. The system of equations for the entire cycle is thus established, and a mathematical solver routine is employed to solve them simultaneously. Property subroutines contained in a separate database serve to provide thermodynamic properties of the working fluids. ABSIM has been employed over the past decade by many users worldwide to simulate a variety of absorption systems in different multi-effect configurations and working fluids. The paper will describe the current capabilities of the program and recent improvements made in it. Improvements to the method of cycle specification and solution have enhanced considerably the convergence capability with large and complex cycles. Additional units and working fluids have been added, resulting in much-enhanced simulation capability and applicability. A Windows version has recently been developed with an improved user-interface, which enhances user-friendliness considerably. It makes it possible to create the cycle diagram on the computer screen, supply the data interactively, observe the results superimposed on the cycle diagram and plot them. The paper describes examples of simulation results for several rather complex cycles, including lithium bromide-water double-, triple- and quadruple-effect cycles and ammonia-water GAX, branched GAX and vapor exchange (VX) cycles. (C) 2001 Elsevier Science Ltd and IIR. All rights reserved. C1 Technion Israel Inst Technol, Fac Mech Engn, IL-32000 Haifa, Israel. Oak Ridge Natl Lab, Div Energy, Oak Ridge, TN 37831 USA. RP Grossman, G (reprint author), Technion Israel Inst Technol, Fac Mech Engn, IL-32000 Haifa, Israel. NR 30 TC 38 Z9 42 U1 0 U2 10 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0140-7007 J9 INT J REFRIG JI Int. J. Refrig.-Rev. Int. Froid PD SEP PY 2001 VL 24 IS 6 BP 531 EP 543 DI 10.1016/S0140-7007(00)00051-7 PG 13 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA 459RQ UT WOS:000170265600009 ER PT J AU Young, DJ Boser, BE Malba, V Bernhardt, AF AF Young, DJ Boser, BE Malba, V Bernhardt, AF TI A micromachined RF low phase noise voltage-controlled oscillator for wireless communications SO INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING LA English DT Article DE RF MEMS; micromachining; micromachined passive components; high-Q RF devices; tunable capacitors; three-dimensional devices; coil inductors; RF VCOs; low phase noise VCOs ID INDUCTORS AB An RF low phase noise voltage-controlled oscillator is implemented with micromachined IC-compatible variable capacitors and three-dimensional coil inductor. Unlike conventional on-chip passive devices, the micromachined variable capacitors achieve a high-Q value above 60 at 1 GHz; with a 15% tuning range for a nominal 2 pF capacitance with 3 V tuning voltage. Three-dimensional inductors minimize the substrate loss and achieve a Q of 30 at 1 GHz with a 4.8 nH inductance. Both passive components are fabricated on silicon substrates and thus amenable to monolithic integration with standard IC process. The prototype VCO exhibits -136 dBc/Hz phase noise at 3 MHz offset frequency from the carrier, suitable for most wireless communication applications, in particular GSM. The VCO is tunable from 855 Mhz to 863 MHz, limited by the test set-up. (C) 2001 John Wiley & Sons, Inc. C1 Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Young, DJ (reprint author), Univ Calif Berkeley, Dept Elect Engn & Comp Sci, Berkeley, CA 94720 USA. EM div@po.cwru.edu NR 23 TC 8 Z9 8 U1 0 U2 1 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1096-4290 J9 INT J RF MICROW C E JI Int. J. RF Microw. Comput-Aid. Eng. PD SEP PY 2001 VL 11 IS 5 BP 285 EP 300 DI 10.1002/mmce.1037 PG 16 WC Computer Science, Interdisciplinary Applications; Engineering, Electrical & Electronic SC Computer Science; Engineering GA 464HN UT WOS:000170527300006 ER PT J AU Ravindra, NM Sopori, B Gokce, OH Cheng, SX Shenoy, A Jin, L Abedrabbo, S Chen, W Zhang, Y AF Ravindra, NM Sopori, B Gokce, OH Cheng, SX Shenoy, A Jin, L Abedrabbo, S Chen, W Zhang, Y TI Emissivity measurements and modeling of silicon-related materials: An overview SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Chem Sci & Technol Lab, Amer Soc Mech Engineers, Div Heat Transfer, Comm Thermophys Properties, Phys & Chem Properties Div HO UNIV COLORADO DE coatings; concentration; doping concentration; emissivity; silicon; surface roughness; temperature; wavelength ID TEMPERATURE-DEPENDENT EMISSIVITY; RADIATIVE PROPERTIES; WAFERS; SI AB An over-view of the emissivity measurements and modeling of silicon-related materials is presented. The experimental component of this investigation is based on results obtained utilizing spectral emissometry. An analysis of the comparison of the measured data with other similar approaches is made. In particular, the celebrated work of Sato is revisited to understand the implications of his study. Simulations of the temperature and wavelength dependent emissivity of silicon based on the semiempirical MULTIRAD model are presented. The influence of doping concentration, surface roughness, and coatings on the emissivity of silicon, as a function of temperature, is discussed. C1 New Jersey Inst Technol, Dept Phys, Newark, NJ 07102 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. JDS Uniphase Corp, Freehold, NJ 07728 USA. BTA Technol, San Jose, CA 95112 USA. RP Ravindra, NM (reprint author), New Jersey Inst Technol, Dept Phys, 161 Warren St, Newark, NJ 07102 USA. NR 20 TC 35 Z9 35 U1 1 U2 22 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD SEP PY 2001 VL 22 IS 5 BP 1593 EP 1611 DI 10.1023/A:1012869710173 PG 19 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 504GD UT WOS:000172848200020 ER PT J AU Petrie, TW Desjarlais, AO Robertson, RH Parker, DS AF Petrie, TW Desjarlais, AO Robertson, RH Parker, DS TI Comparison of techniques for in situ nondamaging measurement of solar reflectances of low-slope roof membranes SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article; Proceedings Paper CT 14th Symposium on Thermophysical Properties CY JUN 25-30, 2000 CL UNIV COLORADO, BOULDER, COLORADO SP Natl Inst Stand & Technol, Chem Sci & Technol Lab, Amer Soc Mech Engineers, Div Heat Transfer, Comm Thermophys Properties, Phys & Chem Properties Div HO UNIV COLORADO DE field measurements; in situ; low-slope roofs; pyranometer; reflectometer; solar reflectance AB With the implementation of the Energy Star Roof Products Program by the U.S. Environmental Protection Agency and the U.S. Department of Energy, techniques are especially needed that yield in situ measurements of the average solar reflectance of roof surfaces without damage to them. This paper presents results of limited field surveys with two types of instruments that permit such measurements. Solar reflectances on a scale from 0 to 1 were obtained by the established laboratory technique for five samples covering the range exhibited by low-slope roofs and coating systems for them. Based on these results, the average bias for one instrument, a portable solar spectrum reflectometer using a built-in light source, was +0.003. The maximum bias for the five samples was +/-0.02. Scatter of readings over a roof area with this instrument depends upon characteristics of the specific surface. Scatter can be as little as +/-0.001 but is typically more than +/-0.02. The other instrument uses a pyranometer and is operated by recording the responses when the pyranometer faces the sun and when it is inverted facing the surface of interest. The reflectance is the ratio of the response when inverted to the response facing the sun. For a variety of roof surfaces, the average of readings with both instruments agreed within 95% confidence intervals of +/-0.02 to +/-0.06, calculated as +/-t.s.d., where t is the t-statistic for the number of measurements and s.d. is the measurement standard deviation. C1 Oak Ridge Natl Lab, Bldg Technol Ctr, Oak Ridge, TN 37831 USA. Firestone Bldg Prod Co, Carmel, IN 46032 USA. Florida Solar Energy Ctr, Cocoa, FL 32922 USA. RP Petrie, TW (reprint author), Oak Ridge Natl Lab, Bldg Technol Ctr, Oak Ridge, TN 37831 USA. NR 14 TC 1 Z9 1 U1 0 U2 3 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD SEP PY 2001 VL 22 IS 5 BP 1613 EP 1628 DI 10.1023/A:1012821827012 PG 16 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA 504GD UT WOS:000172848200021 ER PT J AU Crease, RP AF Crease, RP TI From Hiroshima to the iceman: The development and applications of accelerator mass spectrometry. SO ISIS LA English DT Book Review C1 SUNY Stony Brook, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Crease, RP (reprint author), SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 1427 E 60TH ST, CHICAGO, IL 60637-2954 USA SN 0021-1753 J9 ISIS JI Isis PD SEP PY 2001 VL 92 IS 3 BP 632 EP 633 DI 10.1086/385339 PG 2 WC History & Philosophy Of Science SC History & Philosophy of Science GA 511UY UT WOS:000173285000063 ER PT J AU Stokes, G AF Stokes, G TI Regional climate change SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Editorial Material C1 Pacific NW Natl Lab, Joint Global Change Res Inst, Richland, WA 99352 USA. RP Stokes, G (reprint author), Pacific NW Natl Lab, Joint Global Change Res Inst, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD FAL PY 2001 VL 18 IS 1 BP 21 EP 22 PG 2 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA 492MM UT WOS:000172172200016 ER PT J AU Benedick, RE AF Benedick, RE TI Striking a new deal on climate change SO ISSUES IN SCIENCE AND TECHNOLOGY LA English DT Article C1 Pacific NW Natl Lab, Joint Global Change Res Inst, Richland, WA 99352 USA. Univ Maryland, College Pk, MD 20742 USA. RP Benedick, RE (reprint author), Pacific NW Natl Lab, Joint Global Change Res Inst, Richland, WA 99352 USA. NR 0 TC 11 Z9 11 U1 0 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0748-5492 J9 ISSUES SCI TECHNOL JI Issues Sci. Technol. PD FAL PY 2001 VL 18 IS 1 BP 71 EP 76 PG 6 WC Engineering, Multidisciplinary; Engineering, Industrial; Multidisciplinary Sciences; Social Issues SC Engineering; Science & Technology - Other Topics; Social Issues GA 492MM UT WOS:000172172200035 ER PT J AU Asta, M Ozolins, V Woodward, C AF Asta, M Ozolins, V Woodward, C TI A first-principles approach to modeling alloy phase equilibria SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article ID TIGHT-BINDING APPROACH; NI-ZN SYSTEM; AL-SC ALLOYS; SUBSTITUTIONAL ALLOYS; THERMODYNAMIC PROPERTIES; ELECTRONIC-STRUCTURE; ORDER-DISORDER; VIBRATIONAL ENTROPY; MONTE-CARLO; CR SYSTEM AB This paper presents a brief overview of recent developments in the application of first-principles calculations to the study of bulk and interfacial thermodynamic properties and phase equilibria in alloys. Among the applications discussed are calculations of. bulk thermodynamic properties, phase boundaries, interfacial free energies, and precipitate morphologies. The article concludes by highlighting some further recent developments that are likely to lead to increasing applications of these modeling techniques. C1 Northwestern Univ, Dept Mat Sci & Engn, Evanston, IL 60208 USA. Sandia Natl Labs, Livermore, CA 94550 USA. USAF, Res Lab, Mat & Mfg Directorate, Washington, DC USA. RP Northwestern Univ, Dept Mat Sci & Engn, 2225 N Campus Dr, Evanston, IL 60208 USA. EM m-asta@northwestern.edu RI Ozolins, Vidvuds/D-4578-2009 NR 80 TC 56 Z9 56 U1 0 U2 12 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD SEP PY 2001 VL 53 IS 9 BP 16 EP 19 DI 10.1007/s11837-001-0062-3 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 470LE UT WOS:000170872800003 ER PT J AU Holm, EA Battaile, CC AF Holm, EA Battaile, CC TI The computer simulation of microstructural evolution SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article ID NORMAL GRAIN-GROWTH; POTTS-MODEL; KINETICS; RECRYSTALLIZATION AB This paper reviews the kinetic Monte Carlo Potts model for simulating microstructural evolution. When properly implemented, that model provides a fast and flexible tool for evaluating a variety of materials systems in two and three dimensions, generating snapshots of the evolving microstructure with time. Examples of the model are provided, along with potential applications. C1 Sandia Natl Labs, Mat & Proc Modeling Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Livermore, CA 94550 USA. RP Holm, EA (reprint author), Sandia Natl Labs, Mat & Proc Modeling Dept, POB 5800, Albuquerque, NM 87185 USA. EM eaholm@sandia.gov RI Holm, Elizabeth/S-2612-2016 OI Holm, Elizabeth/0000-0003-3064-5769 NR 36 TC 63 Z9 64 U1 2 U2 17 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD SEP PY 2001 VL 53 IS 9 BP 20 EP 23 DI 10.1007/s11837-001-0063-2 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 470LE UT WOS:000170872800004 ER PT J AU Horstemeyer, MF AF Horstemeyer, MF TI Mapping failure by microstructure-property modeling SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article ID ALUMINUM-ALLOY AB This article describes a math-based microstructure-property model that aus developed based on a multiscale analysis' for ABAQUS finite element analysis. The model was used to determine failure locations, failure loads, and to optimize an automotive component. The model is a function of silicon particle size, casting porosity fraction, casting pore size and nearest neighbor distance, dendrite cell size, temperature, strain rate, and applied stress state. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Horstemeyer, MF (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. OI Horstemeyer, Mark/0000-0003-4230-0063 NR 14 TC 3 Z9 3 U1 0 U2 1 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD SEP PY 2001 VL 53 IS 9 BP 24 EP 27 DI 10.1007/s11837-001-0064-1 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA 470LE UT WOS:000170872800005 ER PT J AU Hang, W Majidi, V AF Hang, W Majidi, V TI Evaluation of ion transport processes in a heated capillary tube interface for electrospray ionization time-of-flight mass spectrometry - Invited lecture SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article; Proceedings Paper CT 2001 European Winter Conference in Plasma Spectrochemistry CY FEB 04-08, 2001 CL LILLEHAMMER, NORWAY AB An electrospray source with a simple heated capillary tube interface for orthogonal ion-extraction time-of-flight mass spectrometry has been evaluated. Alkali metal salts, amino acids, and metallocene samples have been used for characterization of this system. The applied potential on the inlet capillary tube plays in important role oil the ion transport processes as indicated by the net signal and the extent of collision induced dissociation. Adjusting the potential placed on the capillary tube can after the collision energies in this system, allowing the interface to generate both elemental and molecular ions. Initial kinetic energies of ions have been calculated through experiments and modeling. The energy of the ions entering the mass spectrometer is ultimately determined by the net velocity in the supersonic expansion, and by the electric field between the inlet tubing and the sampling orifice. C1 Los Alamos Natl Lab, Div Chem, Los Alamos, NM 87545 USA. RP Majidi, V (reprint author), Los Alamos Natl Lab, Div Chem, MS K484, Los Alamos, NM 87545 USA. NR 21 TC 6 Z9 6 U1 1 U2 3 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD,, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD SEP PY 2001 VL 16 IS 9 BP 938 EP 944 DI 10.1039/b101348n PG 7 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA 477MP UT WOS:000171287600007 ER PT J AU Greeff, CW Trinkle, DR Albers, RC AF Greeff, CW Trinkle, DR Albers, RC TI Shock-induced alpha-omega transition in titanium SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CRYSTAL-STRUCTURES; METALS; PHASE; COMPRESSION; TI; ZR; HF AB Equilibrium free energies for the alpha and omega phases of Ti are constructed. The result is a consistent picture of the ambient pressure, static high pressure, and shock data, as well as first-principles electronic structure calculations. The Hugoniot consists of three segments: a metastable alpha -phase region, a transition region, and an omega -phase branch. All the Hugoniot data are consistent with a transition occurring at similar to 12 GPa. An early identification [R. G. McQueen , in High Velocity Impact Phenomena, edited by R. Kinslow (Academic, New York, 1970)] of a phase transition at 17.5 GPa appears to have been an artifact. The shock Hugoniot extends further into the metastable region than static data, indicating the existence of a relaxation process occurring on a time scale intermediate between those of the static and dynamic measurements. (C) 2001 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Greeff, CW (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Trinkle, Dallas/E-6609-2010; Greeff, Carl/N-3267-2013; OI Greeff, Carl/0000-0003-0529-0441 NR 34 TC 61 Z9 63 U1 2 U2 20 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2001 VL 90 IS 5 BP 2221 EP 2226 DI 10.1063/1.1389334 PG 6 WC Physics, Applied SC Physics GA 465MZ UT WOS:000170593900018 ER PT J AU Yu, KM Walukiewicz, W Wu, J Beeman, JW Ager, JW Haller, EE Shan, W Xin, HP Tu, CW Ridgway, MC AF Yu, KM Walukiewicz, W Wu, J Beeman, JW Ager, JW Haller, EE Shan, W Xin, HP Tu, CW Ridgway, MC TI Formation of diluted III-V nitride thin films by N ion implantation SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID BAND-GAP ENERGY; ELECTRICAL-ACTIVITY; ELECTRONIC STATES; GAINNAS ALLOYS; SOLAR-CELLS; NITROGEN; LAYER; GAAS; INP; COIMPLANTATION AB Diluted III-N-x-V1-x alloys were successfully synthesized by nitrogen implantation into GaAs, InP, and AlyGa1-yAs. In all three cases the fundamental band-gap energy for the ion beam synthesized III-N-x-V1-x alloys was found to decrease with increasing N implantation dose in a manner similar to that observed in epitaxially grown GaNxAs1-x and InNxP1-x alloys. In GaNxAs1-x the highest value of x (fraction of "active" substitutional N on As sublattice) achieved was 0.006. It was observed that N-As is thermally unstable at temperatures higher than 850 degreesC. The highest value of x achieved in InNxP1-x was higher, 0.012, and the N-P was found to be stable to at least 850 degreesC. In addition, the N activation efficiency in implanted InNxP1-x was at least a factor of 2 higher than that in GaNxAs1-x under similar processing conditions. AlyGa1-yNxAs1-x had not been made previously by epitaxial techniques. N implantation was successful in producing AlyGa1-yNxAs1-x alloys. Notably, the band gap of these alloys remains direct, even above the value of y (y >0.44) where the band gap of the host material is indirect. (C) 2001 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif San Diego, Dept Elect & Comp Engn, La Jolla, CA 92093 USA. Australian Natl Univ, Res Sch Phys Sci & Engn, Dept Elect Mat Engn, Canberra, ACT, Australia. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM kmyu@lbl.gov RI Wu, Junqiao/G-7840-2011; Yu, Kin Man/J-1399-2012; Ridgway, Mark/D-9626-2011; OI Wu, Junqiao/0000-0002-1498-0148; Yu, Kin Man/0000-0003-1350-9642; Ridgway, Mark/0000-0002-0642-0108; Ager, Joel/0000-0001-9334-9751 NR 39 TC 36 Z9 36 U1 1 U2 11 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 SEP 1 PY 2001 VL 90 IS 5 BP 2227 EP 2234 DI 10.1063/1.1388860 PG 8 WC Physics, Applied SC Physics GA 465MZ UT WOS:000170593900019 ER PT J AU Devanathan, R Weber, WJ Gao, F AF Devanathan, R Weber, WJ Gao, F TI Atomic scale simulation of defect production in irradiated 3C-SiC SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID SIC SINGLE-CRYSTALS; 6H SILICON-CARBIDE; DISPLACEMENT CASCADES; MOLECULAR-DYNAMICS; COMPUTER-SIMULATION; INTERATOMIC POTENTIALS; INDUCED AMORPHIZATION; AMORPHOUS TRANSITION; METALS; ENERGY AB Molecular dynamics simulations using a modified Tersoff potential have been used to study the primary damage state and statistics of defect production in displacement cascades in 3C-SiC. Recoils with energies from 0.25 to 50 keV have been simulated at 300 K. The results indicate that: (1) the displacement threshold energy surface is highly anisotropic; (2) the dominant surviving defects are C interstitials and vacancies; (3) the defect production efficiency decreases with increasing recoil energy; (4) defect clusters are much smaller and more sparse compared to those reported in metals; and (5) a small fraction of the surviving defects are antisite defects. (C) 2001 American Institute of Physics. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Indian Inst Technol, Dept Met Engn, Madras 600036, Chennai, India. RP Weber, WJ (reprint author), Pacific NW Natl Lab, MS K8-93,POB 999, Richland, WA 99352 USA. RI Weber, William/A-4177-2008; Gao, Fei/H-3045-2012; Devanathan, Ram/C-7247-2008 OI Weber, William/0000-0002-9017-7365; Devanathan, Ram/0000-0001-8125-4237 NR 46 TC 136 Z9 138 U1 6 U2 44 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2001 VL 90 IS 5 BP 2303 EP 2309 DI 10.1063/1.1389523 PG 7 WC Physics, Applied SC Physics GA 465MZ UT WOS:000170593900031 ER PT J AU Takeuchi, I Chang, K Sharma, RP Bendersky, LA Chang, H Xiang, XD Stach, EA Song, CY AF Takeuchi, I Chang, K Sharma, RP Bendersky, LA Chang, H Xiang, XD Stach, EA Song, CY TI Microstructural properties of (Ba, Sr)TiO3 films fabricated from BaF2/SrF2/TiO2 amorphous multilayers using the combinatorial precursor method SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THIN-FILMS; LIBRARIES; BAF2 AB We have investigated the microstructure of (Ba, Sr)TiO3 films fabricated from BaF2/SrF2/TiO2 amorphous multilayers. Rutherford backscattering spectroscopy and x-ray diffraction studies show that a controlled thermal treatment can interdiffuse the multilayers so as to create predominantly single-phase epitaxial (Ba, Sr)TiO3 films. A high resolution cross-sectional transmission electron microscopy investigation of the processed films shows that they consist of large epitaxial grains of (Ba, Sr)TiO3 with atomically sharp interfaces with the LaAlO3 substrates. In addition, we have identified regions where polycrystalline and transient phases exist in small pockets in the film matrix. The results here indicate that the combinatorial thin-film synthesis using precursors can produce (Ba, Sr)TiO3 films in combinatorial libraries which exhibit properties similar to those films made by conventional techniques. (C) 2001 American Institute of Physics. C1 Univ Maryland, Dept Mat Sci & Engn, Small Smart Syst Ctr, College Pk, MD 20742 USA. Univ Maryland, Dept Phys, Ctr Superconduct Res, College Pk, MD 20742 USA. Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Takeuchi, I (reprint author), Univ Maryland, Dept Mat Sci & Engn, Small Smart Syst Ctr, College Pk, MD 20742 USA. RI Xiang, Xiaodong/A-9445-2012; Stach, Eric/D-8545-2011; Xiang, Xiaodong/A-5936-2017 OI Stach, Eric/0000-0002-3366-2153; NR 14 TC 9 Z9 12 U1 0 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD SEP 1 PY 2001 VL 90 IS 5 BP 2474 EP 2478 DI 10.1063/1.1388563 PG 5 WC Physics, Applied SC Physics GA 465MZ UT WOS:000170593900057 ER PT J AU Frank, P Angove, HC Burgess, BK Hodgson, KO AF Frank, P Angove, HC Burgess, BK Hodgson, KO TI Determination of ligand binding constants for the iron-molybdenum cofactor of nitrogenase: monomers, multimers, and cooperative behavior SO JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY LA English DT Article DE FeMoco; nitrogenase; cofactor; iron; molybdenum ID AZOTOBACTER-VINELANDII NITROGENASE; X-RAY-ABSORPTION; DIMENSIONAL W-183 NMR; MOFE3S4 DOUBLE-CUBANE; F-19 CHEMICAL-SHIFTS; SEMI-REDUCED STATES; FEMO-COFACTOR; N-METHYLFORMAMIDE; CATALYTIC REDUCTION; SULFUR CLUSTERS AB Equilibrium titrations in N-methylformamide (NMF) of G-25 gel filtered (ox)-state FeMo cofactor [FeMoco(ox)] from Azobacter vinelandii nitrogenase were carried out using sodium ethanethiolate and followed using UV/Vis absorption spectroscopy. For FeMoco(ox), a non-linear least squares (NLLSQ) fit to the data indicated a strong equilibrium thiolate-binding step with K-eq = 1.3 +/- 0.2x10(6) M-1. With 245 molar excess imidazole, cooperative binding of three ethanethiolates was observed. The best NLLSQ fit gave K-eq = 2.0 +/- 0.1x10(5) M-2 and a Hill coefficient n= 2.0 +/- 0.3. A Scatchard plot of these data was concave upward, indicating positive cooperativity. The fit to previously published data involving benzenethiol titration of the one-electron reduced (semi-reduced) cofactor, FeMoco(sr), as followed by EPR required a model that included both a sub-stoichiometric ratio of thiol to FeMoco(sr) and about five cooperative ligand binding sites. These constraints were met by modeling FeMoco(sr) as an aggregate, with fewer thiol binding sites than FeMoco(sr) units. The best fit model was that of FeMoco(sr) as a dodecamer with five cooperative benzenethiol binding sites, yielding a thiol binding constant of 3.32 +/- 0.09x10(4) M-4.8 and a Hill coefficient n = 4.8 +/- 0.6. The results of all the other published ligand titrations of FeMoco(sr) were similarly analyzed successfully in terms of equilibrium models that include both cooperative ligand binding and dimer-level aggregation. A possible structural model for FeMoco aggregation in NMF solution is proposed. C1 Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Univ Calif Irvine, Sch Biol Sci, Dept Mol Biol & Biochem, Irvine, CA 92697 USA. RP Hodgson, KO (reprint author), Stanford Univ, Dept Chem, Stanford, CA 94305 USA. FU NCRR NIH HHS [RR-01209]; NIGMS NIH HHS [GM-43144] NR 87 TC 4 Z9 4 U1 2 U2 9 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0949-8257 J9 J BIOL INORG CHEM JI J. Biol. Inorg. Chem. PD SEP PY 2001 VL 6 IS 7 BP 683 EP 697 DI 10.1007/s007750100247 PG 15 WC Biochemistry & Molecular Biology; Chemistry, Inorganic & Nuclear SC Biochemistry & Molecular Biology; Chemistry GA 480PB UT WOS:000171469600003 PM 11681702 ER PT J AU Bhattacharyya, MH Wilson, AK Glesne, D Regunathan, A Flores, T AF Bhattacharyya, MH Wilson, AK Glesne, D Regunathan, A Flores, T TI Changes in bone cell gene expression in mice early after cadmium gavage. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 Argonne Natl Lab, Argonne, IL 60439 USA. Benedictine Univ, Lisle, IL USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2001 VL 16 SU 1 BP S488 EP S488 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 467MU UT WOS:000170709001471 ER PT J AU Regunathan, A Bhattacharyya, MH AF Regunathan, A Bhattacharyya, MH TI Participation of fos and src in cadmium-induced bone changes in mice. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 Argonne Natl Lab, Div Biosci, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2001 VL 16 SU 1 BP S418 EP S418 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 467MU UT WOS:000170709001177 ER PT J AU Stock, SR Lee, WK Fezzaa, K Barss, J Dahl, T Veis, A AF Stock, SR Lee, WK Fezzaa, K Barss, J Dahl, T Veis, A TI X-ray absorption microtomography and phase contrast X-radiography of the structure of sea urchin teeth. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 Georgia Inst Technol, Sch Mat Sci & Engn, Wilmette, IL USA. Argonne Natl Lab, Argonne, IL 60439 USA. Northwestern Univ, Sch Med, Dept Cell & Mol Biol, Chicago, IL USA. Northwestern Univ, Sch Med, Chicago, IL USA. NR 0 TC 3 Z9 3 U1 0 U2 1 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2001 VL 16 SU 1 BP S443 EP S443 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 467MU UT WOS:000170709001284 ER PT J AU Wilson, AK Flores, T Bruzik, M Bhattacharyya, MH AF Wilson, AK Flores, T Bruzik, M Bhattacharyya, MH TI Cadmium-induced bone loss is independent of estrogen. SO JOURNAL OF BONE AND MINERAL RESEARCH LA English DT Meeting Abstract C1 Benedictine Univ, Lisle, IL USA. Argonne Natl Lab, Biosci Div, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC BONE & MINERAL RES PI WASHINGTON PA 2025 M ST, N W, STE 800, WASHINGTON, DC 20036-3309 USA SN 0884-0431 J9 J BONE MINER RES JI J. Bone Miner. Res. PD SEP PY 2001 VL 16 SU 1 BP S543 EP S543 PG 1 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA 467MU UT WOS:000170709001720 ER PT J AU Wilkes, KE Gabbard, WA Weaver, FJ Booth, JR AF Wilkes, KE Gabbard, WA Weaver, FJ Booth, JR TI Aging of polyurethane foam insulation in simulated refrigerator panels - Two-year results with third-generation blowing agents SO JOURNAL OF CELLULAR PLASTICS LA English DT Article; Proceedings Paper CT Polyurethanes Conference 2000 CY OCT 08-11, 2000 CL BOSTON, MASSACHUSETTS AB Laboratory data are presented on the effect of constant-temperature aging on the apparent thermal conductivity of polyurethane foam insulation for refrigerators and freezers. The foam specimens were blown with HCFC-141b and with three of its potential replacements-HFC-134a, HFC-245fa, and cyclopentane. Specimens were aged at constant temperatures of 90 degreesF, 40 degreesF, and -10 degreesF. Thermal conductivity measurements were made on two types of specimens: full-thickness simulated refrigerator panels containing foam enclosed between solid plastic sheets, and thin slices of core foam cut from similar panels. Results are presented for the first two years of a multi-year aging study. Preliminary comparisons of measured data with predictions of a mathematical aging model are presented. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Tennessee Technol Univ, Dept Chem Engn, Cookeville, TN 38505 USA. RP Wilkes, KE (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 15 TC 2 Z9 2 U1 0 U2 3 PU SAGE PUBLICATIONS LTD PI LONDON PA 6 BONHILL STREET, LONDON EC2A 4PU, ENGLAND SN 0021-955X J9 J CELL PLAST JI J. Cell. Plast. PD SEP-OCT PY 2001 VL 37 IS 5 BP 400 EP 428 DI 10.1106/N9XJ-PKE1-N3UV-DWJQ PG 29 WC Chemistry, Applied; Polymer Science SC Chemistry; Polymer Science GA 477LH UT WOS:000171284700002 ER PT J AU Rahman, GMM Isenhour, TL Larget, B Greenlaw, PD AF Rahman, GMM Isenhour, TL Larget, B Greenlaw, PD TI Statistical analysis of DOE EML QAP data from 1982 to 1998 SO JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES LA English DT Article AB The historical database from the Environmental Measurements Laboratory's Quality Assessment Program from 1982 to 1998 has been analyzed to determine control limits for future performance evaluations of the different laboratories contracted to the U.S. Department of Energy. Seventy-three radionuclides in four different matrices (air filter, soil, vegetation, and water) were analyzed. The evaluation criteria were established based on a z-score calculation. C1 Duquesne Univ, Dept Chem & Biochem, Pittsburgh, PA 15282 USA. Duquesne Univ, Dept Math & Comp Sci, Pittsburgh, PA 15282 USA. US DOE, Environm Measurements Lab, New York, NY 10014 USA. RP Rahman, GMM (reprint author), Duquesne Univ, Dept Chem & Biochem, Pittsburgh, PA 15282 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0095-2338 J9 J CHEM INF COMP SCI JI J. Chem. Inf. Comput. Sci. PD SEP-OCT PY 2001 VL 41 IS 5 BP 1099 EP 1105 DI 10.1021/ci0000934 PG 7 WC Chemistry, Multidisciplinary; Computer Science, Information Systems; Computer Science, Interdisciplinary Applications SC Chemistry; Computer Science GA 476YZ UT WOS:000171257500001 ER PT J AU Song, Y Qian, XM Lau, KC Ng, CY Liu, JB Chen, WW AF Song, Y Qian, XM Lau, KC Ng, CY Liu, JB Chen, WW TI High-resolution energy-selected study of the reaction CH3X+-> CH3+X: Accurate thermochemistry for the CH3X/CH3X+ (X=Br, I) system SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FIELD IONIZATION-PHOTOELECTRON; PHOTOION COINCIDENCE SPECTROSCOPY; MULTIBUNCH SYNCHROTRON-RADIATION; DISSOCIATION THRESHOLD; MOLECULES; STATES; CH3I; ION; DYNAMICS; BANDS AB Using the high-resolution pulsed field ionization-photoelectron (PFI-PE) and PFI-PE-photoion coincidence (PFI-PEPICO) techniques, we have examined the formation of methyl cation (CH3+) from the dissociation of energy-selected CH3X+ (X=Br and 1) near their dissociation thresholds. The breakdown diagrams for CH3X thus obtained yield values of 12.834 +/- 0.002 eV and 12.269 +/- 0.003 eV for the 0 K dissociative threshold or appearance energy (AE) for CH3+ from CH3Br and CH3I, respectively. Similar to the observation in PFI-PE studies of CH4, C2H2, and NH3, the PFI-PE spectrum for CH3Br exhibits a step at the 0 K AE for CH3+, indicating that the dissociation of excited CH3Br in high-n (greater than or equal to 100) Rydberg states at energies slightly above the dissociation threshold occurs in a time scale of less than or equal to 10(-7) s. The observed step is a confirmation of the 0 K AE(CH3+) from CH3Br determined in the PFI-PEPICO study. The adiabatic ionization energies (IEs) for the CH3Br+ ((X) over tilde E-2(3/2,1/2)) spin-orbit states were determined by PFI-PE measurements to be 10.5427 +/- 0.0010 and 10.8615 +/- 0.0010 eV, respectively, yielding the spin-orbit coupling constant to be 2571 +/- 4 cm(-1). The AE(CH3+) values from CH3Br and CH3I and the IE[CH3Br+ ((X) over tilde E-2(3/2))] value obtained here, when combined with the known IE of CH3 (9.8380 +/- 0.0004 eV) and IE[CH3I+ ((X) over tilde E-2(3/2))] (9.5381 +/- 0.0001 eV), have allowed accurate determination of the 0 K bond dissociation energies for CH3-Br (2.996 +/- 0.002 eV), CH3+-Br (2.291 +/- 0.002 eV), CH3-I (2.431 +/- 0.003 eV), and CH3+-I (2.731 +/- 0.003 eV). Using the AE(CH3+) from CH3Br and CH3I, together with the known 0 K heats of formation (Delta H-f(0)0) for Br (117.93 +/- 0.13 kJ/mol), I (107.16 +/- 0.04 kJ/mol), and CH3+ (1099.05 +/- 0.33 kJ/mol), we have obtained more precise Delta H-f(0)0 demonstrated that highly reliable Delta H-f(0)0 values for a range of molecules with error limits comparable to those for some of the most precisely measured values, such as Delta H-f(0)0(CH4), can be obtained by PFI-PE and PFI-PEPICO measurements. (C) 2001 American Institute of Physics. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Ng, CY (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. OI LAU, Kai Chung /0000-0003-2125-6841 NR 52 TC 32 Z9 33 U1 4 U2 10 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 2001 VL 115 IS 9 BP 4095 EP 4104 DI 10.1063/1.1391268 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 469KV UT WOS:000170813800012 ER PT J AU Parks, EK Nieman, GC Riley, SJ AF Parks, EK Nieman, GC Riley, SJ TI Investigation of structural changes in Ni-19 and Ni-23 induced by adsorption of hydrogen/deuterium and ammonia SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SMALL NICKEL CLUSTERS; COBALT CLUSTERS; IRON AB Two-reagent reactions of Ni-19 and Ni-23 with hydrogen/deuterium and ammonia are studied to probe adsorbate-induced cluster structural changes. H/D and NH3 bind to the clusters noncompetitively, i.e., to different sites, so simultaneous saturation by the two reagents can be achieved. It is found that HID adsorption causes a change in Ni-19 from the double icosahedral structure to a face-centered cubic (fee) or hexagonal close-packed (hcp) one, but that subsequent saturation with NH3 Converts the cluster back to the double icosahedron. No such structural changes are seen for the triple icosahedral Ni-23. The results for Ni-19 are interpreted in terms of the electron withdrawing or donating character of the ligands and the consequent effect on the extent of d-orbital bonding in the cluster. Possible configurations of the H/D atom binding sites on the icosahedral Ni-19 and Ni-23 clusters and on the fcc/hcp Ni-19 cluster are presented. (C) 2001 American Institute of Physics. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Monmouth Coll, Dept Chem, Monmouth, IL 61462 USA. RP Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 13 TC 8 Z9 8 U1 2 U2 5 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 SEP 1 PY 2001 VL 115 IS 9 BP 4125 EP 4131 DI 10.1063/1.1389838 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 469KV UT WOS:000170813800015 ER PT J AU Bordallo, HN Henning, RW Sosman, LP da Fonseca, RJM Tavares, AD Hanif, KM Strouse, GF AF Bordallo, HN Henning, RW Sosman, LP da Fonseca, RJM Tavares, AD Hanif, KM Strouse, GF TI Structural and vibrational study of chromium doped elpasolite crystals Cs2NaAlF6 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID RAMAN-SCATTERING; SELECTION-RULES; TRANSITIONS; LASER; CR-3+; IONS AB The influence of site-symmetry and electron phonon coupling in Cs2NaAlF6:Cr3+ is probed by correlation of optical and structural measurements. Based on neutron and x-ray analysis the structure is a distorted R(3m) over bar $, exhibiting a unique stacking interaction. Selection rules have been used to assign the Raman-active zone-center vibrations. Although local and bulk mode frequencies differ slightly, indicating that the guest Cr3+ ion does not significantly perturb the host structure, vibrational analysis indicates the Cr3+ ion is coupled to the first coordination sphere of the Al-F lattice. (C) 2001 American Institute of Physics. C1 Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. UERJ, Inst Fis, BR-20550 Rio De Janeiro, Brazil. Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. RP Bordallo, HN (reprint author), Argonne Natl Lab, Intense Pulsed Neutron Source, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Sosman, L/I-1549-2013; Bordallo, Heloisa/I-6836-2012 OI Bordallo, Heloisa/0000-0003-0750-0553 NR 33 TC 21 Z9 21 U1 3 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 2001 VL 115 IS 9 BP 4300 EP 4305 DI 10.1063/1.1390530 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 469KV UT WOS:000170813800037 ER PT J AU Bartels, DM AF Bartels, DM TI Moment analysis of hydrated electron cluster spectra: Surface or internal states? SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID WATER CLUSTERS; ABSORPTION-SPECTRA; OPTICAL-ABSORPTION; SOLVATED ELECTRONS; SPECTROSCOPY; DYNAMICS C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Bartels, DM (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 16 TC 49 Z9 49 U1 0 U2 8 PU AMER INST PHYSICS PI MELVILLE PA 2 HUNTINGTON QUADRANGLE, STE 1NO1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD SEP 1 PY 2001 VL 115 IS 9 BP 4404 EP 4405 DI 10.1063/1.1391476 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 469KV UT WOS:000170813800051 ER PT J AU Kam, SI Gauglitz, PA Rossen, WR AF Kam, SI Gauglitz, PA Rossen, WR TI Effective compressibility of a bubbly slurry. I. Theory of the behavior of bubbles trapped in porous media SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE compressibility; bubbles; porous media; theory; Haines Jump ID MOBILIZATION; FOAMS AB Bubbles trapped within the slurry at the bottom of waste tanks at the Hanford Site expand and contract in response to ambient pressure changes. These bubbles contain hydrogen and other flammable gases that can pose a safety hazard. Determining the effective compressibility of bubbles in the slurry could allow one to make improved estimates of the quantity of gas trapped in the slurry from changes in slurry volume with ambient pressure changes. More broadly, the diffusive growth and mechanical properties of bubbles in a porous medium are important issues in a number of applications. Numerical calculations based on a one-dimensional biconical-pore-network model show that the effective compressibility of a population of bubbles shows hysteresis with pressure increase and decrease. This hysteresis is caused by the sudden jumps of interfaces from pore throat to throat during a pressure decrease and from pore body to body during a pressure increase. Snap-off may occur during these jumps but does not significantly alter the effective compressibility of the population of bubbles. (C) 2001 Academic Press. C1 Univ Texas, Dept Petr & Geosyst Engn, Austin, TX 78712 USA. Pacific NW Natl Lab, Richland, WA USA. RP Rossen, WR (reprint author), Univ Texas, Dept Petr & Geosyst Engn, Austin, TX 78712 USA. NR 21 TC 4 Z9 4 U1 3 U2 6 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD SEP 1 PY 2001 VL 241 IS 1 BP 248 EP 259 DI 10.1006/jcis.2001.7665 PG 12 WC Chemistry, Physical SC Chemistry GA 467XT UT WOS:000170729600026 ER PT J AU Kam, SI Gauglitz, PA Rossen, WR AF Kam, SI Gauglitz, PA Rossen, WR TI Effective compressibility of a bubbly slurry II. Fitting numerical results to field data and implications SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE compressibility; bubbles; porous media; theory; Hanford Site AB The goal of this study is to fit model parameters to changes in waste level in response to barometric pressure changes in underground storage tanks at the Hanford Site. This waste compressibility is a measure of the quantity of gas, typically hydrogen and other flammable gases, that can pose a safety hazard, retained in the waste. A one-dimensional biconical-pore-network model for compressibility of a bubbly slurry is presented in a companion paper. Fitting these results to actual waste level changes in the tanks implies that bubbles in the slurry layer are long and the ratio of pore-body radius to pore-throat radius is close to 1; unfortunately, compressibility can not be quantified unambiguously from the data without additional information on pore geometry. Therefore, determining the quantity of gas in the tanks requires more than just waste-level data. The non-uniqueness of the fit is also found with two other simple models: a capillary-tube model with contact angle hysteresis and a spherical-pore model. (C) 2001 Academic Press. C1 Univ Texas, Dept Petr & Geosyst Engn, Austin, TX 78712 USA. Pacific NW Natl Lab, Richland, WA USA. RP Rossen, WR (reprint author), Univ Texas, Dept Petr & Geosyst Engn, Austin, TX 78712 USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD SEP 1 PY 2001 VL 241 IS 1 BP 260 EP 268 DI 10.1006/jcis.2001.7666 PG 9 WC Chemistry, Physical SC Chemistry GA 467XT UT WOS:000170729600027 ER PT J AU Carr, R Fujito, T Konjevod, G Parekh, O AF Carr, R Fujito, T Konjevod, G Parekh, O TI A 21/10-approximation algorithm for a generalization of the weighted edge-dominating set problem SO JOURNAL OF COMBINATORIAL OPTIMIZATION LA English DT Article DE approximation algorithm; edge-dominating set; vertex cover; edge cover ID APPROXIMATION ALGORITHMS; GRAPHS AB We study the approximability of the weighted edge-dominating set problem. Although even the unweighted case is NP-Complete, in this case a solution of size at most twice the minimum can be efficiently computed due to its close relationship with minimum maximal matching; however, in the weighted case such a nice relationship is not known to exist. In this paper, after showing that weighted edge domination is as hard to approximate as the well studied weighted vertex cover problem, we consider a natural strategy, reducing edge-dominating set to edge cover. Our main result is a simple 2 1/10-approximation algorithm for the weighted edge-dominating set problem, improving the existing ratio, due to a simple reduction to weighted vertex cover, of 2r(WVC), where r(WVC) is the approximation guarantee of any polynomial-time weighted vertex cover algorithm. The best value of r(WVC) currently stands at 2-log log |V|/2 log |V|. Furthermore we establish that the factor of 2 1/10 is tight in the sense that it coincides with the integrality gap incurred by a natural linear programming relaxation of the problem. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Nagoya Univ Furo, Dept Elect, Chikusa Ku, Nagoya, Aichi 4648603, Japan. Carnegie Mellon Univ, Dept Math Sci, Pittsburgh, PA 15213 USA. RP Carr, R (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 18 TC 20 Z9 22 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1382-6905 J9 J COMB OPTIM JI J. Comb. Optim. PD SEP PY 2001 VL 5 IS 3 BP 317 EP 326 DI 10.1023/A:1011445210568 PG 10 WC Computer Science, Interdisciplinary Applications; Mathematics, Applied SC Computer Science; Mathematics GA 462FU UT WOS:000170410700004 ER PT J AU Korneev, VA Johnson, LR AF Korneev, VA Johnson, LR TI Fluctuations of elastic waves due to random scattering from inclusions SO JOURNAL OF COMPUTATIONAL ACOUSTICS LA English DT Article; Proceedings Paper CT 4th International Conference on Theoretical and Computational Acoustics (ICTCA) CY MAY 10-14, 1999 CL TRIESTE, ITALY ID INHOMOGENEOUS LITHOSPHERE; AMPLITUDE ATTENUATION; MULTIPLE-SCATTERING; SPHERICAL INCLUSION; HETEROGENEOUS LAYER; SEISMIC-WAVES; MEDIA; TIME; VELOCITY AB Exact solutions for elastic compressional and shear waves scattered from a homogeneous sphere are used to obtain formulas for fluctuations of velocity and attenuation of plane waves propagating through a layer of randomly distributed inclusions over a broad range of frequencies. The size and contrast of the inclusions axe arbitrary, but interactions between scatterers are not considered and the concentration of scatterers is assumed to be small. The analytical solutions are also compared with numerical simulations and it is demonstrated that they satisfactorily explain the effects of scattering on both the mean and variance of the phase and the mean and variance of the attenuation. The need for spatial averaging of observational data and methods of interpreting such averaged data in terms of the material properties of the scattering medium are discussed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Computat Seismol, Berkeley, CA 94720 USA. RP Korneev, VA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Computat Seismol, Berkeley, CA 94720 USA. EM vakorneev@lbl.gov; lrj@ccs.lbl.gov NR 34 TC 2 Z9 2 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-396X EI 1793-6489 J9 J COMPUT ACOUST JI J. Comput. Acoust. PD SEP PY 2001 VL 9 IS 3 BP 973 EP 991 PG 19 WC Acoustics; Mathematics, Interdisciplinary Applications SC Acoustics; Mathematics GA 494MC UT WOS:000172285600021 ER PT J AU Marshall, AW Meza, JC Olkin, I AF Marshall, AW Meza, JC Olkin, I TI Can data recognize its parent distribution? SO JOURNAL OF COMPUTATIONAL AND GRAPHICAL STATISTICS LA English DT Article DE gamma distribution; geometric extreme distribution; lifetime data; lognormal distribution; model choice; survival distributions; Weibull distribution ID HYPOTHESES; SELECTION; FAMILIES; MODELS AB This study is concerned with model selection of lifetime and survival distributions arising in engineering reliability or in the medical sciences. We compare various distributions-including the gamma, Weibull, and lognormal-with a new distribution called geometric extreme exponential. Except for the lognormal distribution, the other three distributions all have the exponential distribution as special cases. A Monte Carlo simulation was performed to determine sample sizes for which survival distributions can distinguish data generated by their own families. Two methods for decision are by maximum likelihood and by Kolmogorov distance. Neither method is uniformly best. The probability of correct selection with more than one alternative shows some surprising results when the choices are close to the exponential distribution. C1 Western Washington Univ, Lummi Isl, WA 98262 USA. Sandia Natl Labs, Computat Sci & Math Res Dept, MS 9217, Livermore, CA 94551 USA. Stanford Univ, Dept Stat, Stanford, CA 94305 USA. RP Marshall, AW (reprint author), Western Washington Univ, 2781 W Shore Dr, Lummi Isl, WA 98262 USA. RI Meza, Juan/B-5601-2012; OI Meza, Juan/0000-0003-4543-0349 NR 28 TC 18 Z9 19 U1 0 U2 0 PU AMER STATISTICAL ASSOC PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 USA SN 1061-8600 J9 J COMPUT GRAPH STAT JI J. Comput. Graph. Stat. PD SEP PY 2001 VL 10 IS 3 BP 555 EP 580 DI 10.1198/106186001317115117 PG 26 WC Statistics & Probability SC Mathematics GA 477FG UT WOS:000171271900009 ER PT J AU Petersson, NA AF Petersson, NA TI Stability of pressure boundary conditions for Stokes and Navier-Stokes equations SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE incompressible Navier-Stokes; velocity-pressure formulation; normal-mode analysis; chimera grids AB The stability of a finite difference discretization of the time-dependent incompressible Navier-Stokes equations in velocity-pressure formulation is studied. In paticular, we compare the stability for different pressure boundary conditions in a semiimplicit time-integration scheme. where only the viscous term is treated implicitly. The stability is studied in three different ways: by a normal-mode analysis, by numerical computation of the amplification factors, and by direct numerical simulation of the governing equations. All three approaches identify the same pressure boundary condition as the best alternative. This condition implicitly enforces the normal derivative of the divergence to be zero on the boundary by coupling the normal derivative of the pressure to the normal component of the curl of the vorticity. Using this boundary condition. we demonstrate that the time-step is determined only by the convective term. (C) 2001 Academic Press. C1 Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. RP Petersson, NA (reprint author), Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. NR 12 TC 31 Z9 31 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 1 PY 2001 VL 172 IS 1 BP 40 EP 70 DI 10.1006/jcph.2001.6754 PG 31 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 467XQ UT WOS:000170729400003 ER PT J AU Kuprat, A Khamayseh, A George, D Larkey, L AF Kuprat, A Khamayseh, A George, D Larkey, L TI Volume conserving smoothing for piecewise linear curves, surfaces, and triple lines SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID GRID GENERATION AB We present smoothing algorithms for piecewise linear curves, surfaces, and triple lines of intersection of surfaces that are based on the the idea of sequentially relaxing either individual nodes or edges in the mesh. Each relaxation is designed both to smooth the mesh and to conserve down to round-off error the area or volume enclosed by the curve or surface. For the case of smoothing surfaces and lines of intersection of surfaces, each relaxation consists of a pure smoothing component and a volume conserving correction which is chosen to be of minimum norm. Since surfaces and triple intersection lines can be conservatively smoothed, the algorithms are suitable for improving multimaterial grids used by physics simulations where exactly conserving the volume of each individual material may be a requirement or at least highly desirable. The algorithms are also suitable for smoothing piecewise linear functions of one or two variables while simultaneously preserving their integrals. We show examples of the application of the more powerful edge-based algorithms to curve, surface, and multimaterial volume grids and to a thin film simulation. (C) 2001 Academic Press. C1 Los Alamos Natl Lab, Div Theoret, Grp T1, Los Alamos, NM 87545 USA. Oak Ridge Natl Lab, Div Math & Comp Sci, Oak Ridge, TN 37831 USA. Univ Texas, Texas Inst Computat & Appl Math, Austin, TX 78712 USA. RP Kuprat, A (reprint author), Los Alamos Natl Lab, Div Theoret, Grp T1, Mailstop B-221, Los Alamos, NM 87545 USA. OI Kuprat, Andrew/0000-0003-4159-918X NR 10 TC 39 Z9 39 U1 1 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD SEP 1 PY 2001 VL 172 IS 1 BP 99 EP 118 DI 10.1006/jcph.2001.6816 PG 20 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 467XQ UT WOS:000170729400005 ER PT J AU Hu, QH Salve, R Stringfellow, WT Wang, JSY AF Hu, QH Salve, R Stringfellow, WT Wang, JSY TI Field tracer-transport tests in unsaturated fractured tuff SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE unsaturated zone; release rate; fracture-matrix interaction; flow pathway; Yucca Mountain ID FAST PREFERENTIAL FLOW; NONREACTIVE TRACERS; SOIL; INTERRUPTION; GROUNDWATER; MECHANISMS; WATER AB This paper presents the results of a field investigation in the unsaturated, fractured welded tuff within the Exploratory Studies Facility (ESF) at Yucca Mountain, NV. This investigation included a series of tests during which tracer-laced water was released into a high-permeability zone within " horizontal injection borehole. The tracer concentration was monitored in the seepage collected in an excavated slot about 1.6 m below the borehole. Results showed significant variability in the hydrologic response of fractures and the matrix. Analyses of the breakthrough curves suggest that flow and transport pathways are dynamic, rather than fixed, and related to liquid-release rates. Under high release rates, fractures acted as the predominant flow pathways, with limited fracture-matrix interaction. Under low release rates, fracture flow was comparatively less dominant, with a noticeable contribution from matrix flow. Observations of tracer concentrations rebounding in seepage water, following an interruption of flow, provided evidence of mass exchange between the fast-flowing fractures and slow- or non-flowing regions. The tests also showed the applicability of fluorinated benzoate tracers in situations where multiple tracers of similar physical properties are warranted. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Hu, QH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, 1 Cyclotron Rd,MS 90-1116, Berkeley, CA 94720 USA. RI Hu, Qinhong/C-3096-2009; Stringfellow, William/O-4389-2015 OI Hu, Qinhong/0000-0002-4782-319X; Stringfellow, William/0000-0003-3189-5604 NR 19 TC 12 Z9 13 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7722 J9 J CONTAM HYDROL JI J. Contam. Hydrol. PD SEP PY 2001 VL 51 IS 1-2 BP 1 EP 12 DI 10.1016/S0169-7722(01)00124-3 PG 12 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA 463JJ UT WOS:000170473100001 PM 11530924 ER PT J AU Bourret-Courchesne, ED Ye, Q Yu, KM Ager, JW AF Bourret-Courchesne, ED Ye, Q Yu, KM Ager, JW TI Evolution of crystallinity of GaN layers grown at low temperature on sapphire with dimethylhydrazine and triethylgallium SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE characterization; nucleation; chemical vapor deposition processes; metalorganic vapor phase epitaxy; gallium compounds; nitrides; semiconducting gallium compounds; semiconducting materials ID CHEMICAL-VAPOR-DEPOSITION; BUFFER LAYERS; PHASE EPITAXY; RAMAN-SCATTERING; CUBIC GAN; FILMS; MOVPE; PYROLYSIS; GAAS AB The crystallinity of GaN layers grown at low temperature by organometallic vapor phase epitaxy on sapphire using dimethylhydrazine and triethylgallium has been studied with Raman spectroscopy, atomic force microscopy and Rutherford backscattering spectroscopy. The layers were grown in the temperature range from 520 degreesC to 660 degreesC. Amorphous, possibly non-stoichiometric Ga-rich layers were produced below 560 degreesC. Smooth layers of crystalline GaN with a disordered structure were produced between 560 degreesC and 600 degreesC. Rough but crystalline layers were produced at higher temperatures. The minimum temperature for production of crystalline layers occurs at about 580 degreesC. (C) 2001 Published by Elsevier Science B.V. C1 Lawrence Berkeley Natl Lab, Div Sci Mat, Ctr Adv Mat, Berkeley, CA 94720 USA. RP Bourret-Courchesne, ED (reprint author), Lawrence Berkeley Natl Lab, Div Sci Mat, Ctr Adv Mat, Mail Stop 2-200,1 Cyclotron Rd, Berkeley, CA 94720 USA. EM EDBourret@lbl.gov RI Yu, Kin Man/J-1399-2012; OI Yu, Kin Man/0000-0003-1350-9642; Ager, Joel/0000-0001-9334-9751 NR 26 TC 1 Z9 1 U1 0 U2 4 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 SEP PY 2001 VL 231 IS 1-2 BP 89 EP 94 DI 10.1016/S0022-0248(01)01488-9 PG 6 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA 457DV UT WOS:000170122600013 ER PT J AU Schieber, M James, RB Hermon, H Vilensky, A Baydjanov, I Goorsky, M Lam, T Meerson, E Yao, HW Erickson, J Cross, E Burger, A Ndap, JO Wright, G Fiederle, M AF Schieber, M James, RB Hermon, H Vilensky, A Baydjanov, I Goorsky, M Lam, T Meerson, E Yao, HW Erickson, J Cross, E Burger, A Ndap, JO Wright, G Fiederle, M TI Comparison of cadmium zinc telluride crystals grown by horizontal and vertical Bridgman and from the vapor phase SO JOURNAL OF CRYSTAL GROWTH LA English DT Article DE impurities; segregation; X-ray diffraction; X-ray topography; Bridgman technique; cadmium compounds; semiconducting II-IV materials ID THERMOELECTRIC EMISSION-SPECTROSCOPY; THERMALLY STIMULATED CONDUCTIVITY; CDZNTE RADIATION DETECTORS; CZT AB Characterization studies of Cd1-xZnxTe (0 ggamma. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. EM bern@physics.ucla.edu; freitas@physics.ucla.edu; lance@slac.stanford.edu NR 82 TC 89 Z9 89 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD SEP PY 2001 IS 9 AR 037 PG 25 WC Physics, Particles & Fields SC Physics GA 511NW UT WOS:000173273200037 ER PT J AU Bodeker, D Laine, M AF Bodeker, D Laine, M TI Finite baryon density effects on gauge field dynamics SO JOURNAL OF HIGH ENERGY PHYSICS LA English DT Article DE QCD; thermal field theory; global symmetries; nonperturbative effects ID HARD THERMAL LOOPS; QUARK-GLUON PLASMA; CLASSICAL TRANSPORT-THEORY; SIMONS NUMBER DIFFUSION; ADJOINT HIGGS-MODEL; HIGH-TEMPERATURE; DIMENSIONAL REDUCTION; CURVED SPACETIME; WILSON LINE; DEBYE MASS AB We discuss the effective action for QCD gauge fields at finite temperatures and densities, obtained after integrating out the hardest momentum scales from the system. We show that a non-vanishing baryon density induces a charge conjugation (C) odd operator to the gauge field action, proportional to the chemical potential. Even though it is parametrically smaller than the leading C even operator, it could have an important effect on C odd observables. The same operator appears to be produced by classical kinetic theory, allowing in principle for a non-perturbative study of such processes. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Brookhaven Natl Lab, RIKEN BNL Res Ctr, Upton, NY 11973 USA. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. EM bodeker@bnl.gov; mikko.laine@cern.ch NR 44 TC 8 Z9 8 U1 0 U2 0 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 1029-8479 J9 J HIGH ENERGY PHYS JI J. High Energy Phys. PD SEP PY 2001 IS 9 AR 029 PG 21 WC Physics, Particles & Fields SC Physics GA 511NW UT WOS:000173273200029 ER PT J AU Long, SA Quan, C de Water, JV Nantz, MH Kurth, MJ Barsky, D Colvin, ME Lam, KS Coppel, RL Ansari, A Gershwin, ME AF Long, SA Quan, C de Water, JV Nantz, MH Kurth, MJ Barsky, D Colvin, ME Lam, KS Coppel, RL Ansari, A Gershwin, ME TI Immunoreactivity of organic mimeotopes of the E2 component of pyruvate dehydrogenase: Connecting xenobiotics with primary biliary cirrhosis SO JOURNAL OF IMMUNOLOGY LA English DT Article ID MOLECULAR MIMICRY; LIPOIC ACID; ANTIMITOCHONDRIAL ANTIBODIES; HUMAN CYTOCHROME-P450; HALOTHANE HEPATITIS; AUTOANTIGENS; MITOCHONDRIA; MECHANISMS; ISOFLURANE; DISEASE AB In primary biliary cirrhosis (PBC), the major autoepitope recognized by both T and B cells is the inner lipoyl domain of the E2 component of pyruvate dehydrogenase. To address the hypothesis that PBC is induced by xenobiotic exposure, we took advantage of ab initio quantum chemistry and synthesized the inner lipoyl domain of E2 component of pyruvate dehydrogenase, replacing the lipoic acid moiety with synthetic structures designed to mimic a xenobiotically modified lipoyl hapten, and we quantitated the reactivity of these structures with sera from PBC patients. Interestingly, antimitochondrial Abs from all seropositive patients with PBC, but no controls, reacted against 3 of the 18 organic modified autoepitopes significantly better than to the native domain. By structural analysis, the features that correlated with autoantibody binding included synthetic domain peptides with a halide or methyl halide in the meta or para position containing no strong hydrogen bond accepting groups on the phenyl ring of the lysine substituents, and synthetic domain peptides with a relatively low rotation barrier about the linkage bond. Many chemicals including pharmaceuticals and household detergents have the potential to form such halogenated derivatives as metabolites. These data reflect the first time that an organic compound has been shown to serve as a mimeotope for an autoantigen and further provide evidence for a potential mechanism by which environmental organic compounds may cause PBC. C1 Univ Calif Davis, Sch Med, Div Rheumatol Allergy & Clin Immunol, Davis, CA 95616 USA. Univ Calif Davis, Sch Med, Div Hematol & Oncol, Davis, CA 95616 USA. Univ Calif Davis, Sch Med, Dept Chem, Davis, CA 95616 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Monash Univ, Dept Microbiol, Clayton, Vic 3168, Australia. Emory Univ, Dept Pathol, Atlanta, GA 30322 USA. RP Gershwin, ME (reprint author), Univ Calif Davis, Sch Med, Div Rheumatol Allergy & Clin Immunol, TB 192,1 Shields Ave, Davis, CA 95616 USA. RI Coppel, Ross/A-6626-2008 OI Coppel, Ross/0000-0002-4476-9124 FU NIDDK NIH HHS [DK39588]; NIEHS NIH HHS [ES103019] NR 39 TC 119 Z9 123 U1 0 U2 3 PU AMER ASSOC IMMUNOLOGISTS PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0022-1767 J9 J IMMUNOL JI J. Immunol. PD SEP 1 PY 2001 VL 167 IS 5 BP 2956 EP 2963 PG 8 WC Immunology SC Immunology GA 496JE UT WOS:000172391800067 PM 11509645 ER PT J AU Hu, JZ Taylor, CMV Pugmire, RJ Grant, DM AF Hu, JZ Taylor, CMV Pugmire, RJ Grant, DM TI A novel dipolar dephasing method for the slow magic angle turning experiment SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE dipolar dephasing in slow MAT experiments; chemical shift tensor; FIREMAT and 2D-PASS ID TENSOR PRINCIPAL VALUES; SOLID-STATE NMR; SPINNING NMR; RESOLUTION; SPECTRA AB Complete suppression of the resonances from protonated carbons in a slow magic angle spinning experiment can be achieved using five dipolar dephasing (Five-DD) periods distributed in one rotor period. This produces a spectrum containing only the spinning sidebands (SSB) from the nonprotonated carbons. It is shown that the SSB patterns corresponding to the nonprotonated carbons are not distorted over a wide range of dipolar dephasing times. Hence, this method can be used to obtain reliable principal values of the chemical shift tensors for each nonprotonated carbon. The Five-DD method can be readily incorporated into isotropic-anisotropic 2D experiments such as FIREMAT and 2D-PASS to facilitate the measurement of the C-13 chemical shift tensors in complex systems. (C) 2001 Academic Press. C1 Univ Utah, Dept Chem, Salt Lake City, UT 84112 USA. Univ Utah, Dept Chem & Fuels Engn, Salt Lake City, UT 84112 USA. Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Hu, JZ (reprint author), Pacific NW Natl Lab, POB 999,MS K8-98, Richland, WA 99352 USA. RI Hu, Jian Zhi/F-7126-2012 FU NIGMS NIH HHS [GM 08521-37] NR 15 TC 4 Z9 4 U1 1 U2 3 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD SEP PY 2001 VL 152 IS 1 BP 7 EP 13 DI 10.1006/jmre.2001.2380 PG 7 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 472QD UT WOS:000170995700002 PM 11531359 ER PT J AU Rubin, SM Spence, MM Pines, A Wemmer, DE AF Rubin, SM Spence, MM Pines, A Wemmer, DE TI Characterization of the effects of nonspecific xenon-protein interactions on Xe-129 chemical shifts in aqueous solution: Further development of xenon as a biomolecular probe SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article DE xenon NMR; Xe-129 chemical shifts; xenon-protein interactions; biomolecular probes ID NUCLEAR-MAGNETIC-RESONANCE; LASER-POLARIZED XENON; NMR; CAVITIES; MYOGLOBIN; ZEOLITES; SOLVENTS; SOLIDS; BLOOD; GAS AB The sensitivity of Xe-129 chemical shifts to weak nonspecific xenon-protein interactions has suggested the use of xenon to probe biomolecular structure and interactions. The realization of this potential necessitates a further understanding of how different macromolecular properties influence the Xe-129 chemical shift in aqueous solution. Toward this goal, we have acquired Xe-129 NMR spectra of xenon dissolved in amino acid, peptide, and protein solutions under both native and denaturing conditions. In general, these cosolutes induce Xe-129 chemical shifts that are downfield relative to the shift in water, as they deshield the xenon nucleus through weak, diffusion-mediated interactions. Correlations between the extent of deshielding and molecular properties including chemical identity, structure, and charge are reported. Xenon deshielding was found to depend linearly on protein size under denaturing solution conditions; the denaturant itself has a characteristic effect on the Xe-129 chemical shift that likely results from a change in the xenon solvation shell structure. In native protein solutions, contributions to the overall Xe-129 chemical shift arise from the presence of weak xenon binding either in cavities or at the protein surface. Potential applications of xenon as a probe of biological systems including the detection of conformational changes and the possible quantification of buried surface area at protein-protein interfaces are discussed. (C) 2001 Academic Press. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Wemmer, DE (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 34 TC 43 Z9 43 U1 1 U2 4 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD SEP PY 2001 VL 152 IS 1 BP 79 EP 86 DI 10.1006/jmre.2001.2389 PG 8 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA 472QD UT WOS:000170995700009 PM 11531366 ER PT J AU Niu, XJ Gschneidner, KA Pecharsky, AO Pecharsky, VK AF Niu, XJ Gschneidner, KA Pecharsky, AO Pecharsky, VK TI Crystallography, magnetic properties and magnetocaloric effect in Gd-4(BixSb1-x)(3) alloys SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE Gd-4(BixSb1-x)(3) alloys; magnetocaloric effect; Curie temperature; DC magnetization; AC magnetic susceptibility; lattice parameters; heat capacity AB A study of magnetic and thermal properties has been carried out on the alloys from the Gd-4(BixSb1-x)(3) series with x = 0, 0.25, 0.5, 0.75, and 1. All of the alloys are ferromagnetic below their respective Curie temperatures which vary from 266 K for x = 0 to 332 K for x = 1.0. The magnetocaloric effect calculated from the temperature and magnetic field dependencies of the magnetization and heat capacity is moderate when compared to that of other materials, which order in the same temperature range. Both the magnetic ordering and the magnetocaloric effect peak temperatures increase nearly linearly with the increasing Bi content. Experimental magnetocaloric effect data obtained from two different measurement techniques are in excellent agreement. Published by Elsevier Science B.V. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Gschneidner, KA (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 12 TC 22 Z9 24 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD SEP PY 2001 VL 234 IS 2 BP 193 EP 206 DI 10.1016/S0304-8853(01)00391-2 PG 14 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 467RW UT WOS:000170718400001 ER PT J AU Zarestky, JL Vaknin, D Chakoumakos, BC Rojo, T Goni, A Barberis, GE AF Zarestky, JL Vaknin, D Chakoumakos, BC Rojo, T Goni, A Barberis, GE TI Antiferromagnetism in alpha-Li3Fe2(PO4)(3) SO JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS LA English DT Article DE lithium-iron-phosphate; neutron-diffraction; antiferromagnet; phase-transition; crystal-structure ID LI3FE2(PO4)(3); LI3CR2(PO4)3 AB Neutron diffraction techniques have been used to determine the magnetic structure of Fe in monoclinic alpha -Li3Fe2(PO4)(3). Rietveld analysis of the room temperature powder diffraction pattern confirms the monoclinic structure of the sample and is in agreement with previous studies. At low temperatures a paramagnetic to antiferromagnetic transition is observed at T-N = 30.0 K. Our analysis shows that at T = 4 K the two inequivalent Fe sites have antiparallel magnetic moments that are aligned along the a-axis. The average magnetic moment, gS = 5.0 mu (B) indicates homogeneous Fe3+ (S = 5/2). (C) 2001 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Basque Country, Fac Ciencias, Dept Quim Inorgan, Euskal Herriko Unibertsitatea, E-48080 Bilbao, Spain. Univ Estadual Campinas, Dept Eletron Quant, Inst Fis Gleb Wataghin, BR-13083970 Campinas, SP, Brazil. RP Vaknin, D (reprint author), Iowa State Univ Sci & Technol, Ames Lab, A500, Ames, IA 50011 USA. EM vaknin@ameslab.gov RI Rojo, Teofilo/B-5197-2015; Chakoumakos, Bryan/A-5601-2016; Vaknin, David/B-3302-2009; Inst. of Physics, Gleb Wataghin/A-9780-2017 OI Rojo, Teofilo/0000-0003-2711-8458; Chakoumakos, Bryan/0000-0002-7870-6543; Vaknin, David/0000-0002-0899-9248; NR 17 TC 18 Z9 19 U1 0 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-8853 J9 J MAGN MAGN MATER JI J. Magn. Magn. Mater. PD SEP PY 2001 VL 234 IS 3 BP 401 EP 408 DI 10.1016/S0304-8853(01)00425-5 PG 8 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 475XC UT WOS:000171194100007 ER PT J AU Leventouri, T Chakoumakos, BC Papanearchou, N Perdikatsis, V AF Leventouri, T Chakoumakos, BC Papanearchou, N Perdikatsis, V TI Comparison of crystal structure parameters of natural and synthetic apatites from neutron powder diffraction SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID HYDROXYAPATITE AB A systematic behavior in the crystal structure parameters of natural, synthetic, carbonate, and non-carbonate apatite is revealed from Rielveld refinements of neutron powder diffraction experiments. The results of this work on synthetic carbonate hydroxyapatites (CHAps) are consistent with the mechanism of carbonate substitution on the mirror plane of the phosphate tetrahedron, as it was introduced for the natural carbonate fluorapatite (CFAp). The present comparison shows that the tetrahedral bond lengths P-O1 and P-O2 decrease by 3-4% in all carbonate apatites. The atomic displacement parameters (ADPs) of the tetrahedral (T) and the O3 sites are greater in the carbonate than in the non-carbonate apatites. The atomic positional disorder of the T site (P/C site) is greater in the CFAp than in the CHAps, while the opposite happens at the O3 sites. Finally, the room-temperature ADPs of all of the atoms in the CFAp and CHAps show the same behavior as in the corresponding non-carbonate materials. C1 Florida Atlantic Univ, Dept Phys, Boca Raton, FL 33431 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Inst Geol & Mineral Explorat, Athens 11527, Greece. RP Leventouri, T (reprint author), Florida Atlantic Univ, Dept Phys, Boca Raton, FL 33431 USA. RI Chakoumakos, Bryan/A-5601-2016 OI Chakoumakos, Bryan/0000-0002-7870-6543 NR 18 TC 30 Z9 30 U1 0 U2 10 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 2001 VL 16 IS 9 BP 2600 EP 2606 DI 10.1557/JMR.2001.0357 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA 470XZ UT WOS:000170898900023 ER PT J AU Ushakov, SV Helean, KB Navrotsky, A Boatner, LA AF Ushakov, SV Helean, KB Navrotsky, A Boatner, LA TI Thermochemistry of rare-earth orthophosphates SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID DOPED LUTETIUM ORTHOPHOSPHATE; ELECTRON-MICROPROBE ANALYSIS; HIGH-TEMPERATURE CALORIMETRY; MECHANOCHEMICAL CHANGES; OPTICAL SPECTROSCOPY; ORTHO-PHOSPHATE; SOLID-SOLUTIONS; ZIRCON; SCINTILLATORS; MONAZITE AB The enthalpies of formation for the compounds (RE (3+))PO4, (where RE = Sc, Y, La-Nd, Sm-Lu) were determined by oxide-melt solution calorimetry. Calorimetric measurements were performed in a Calvet-type twin microcalorimeter in sodium molybdate (3Na(2)O . 4MoO(3)) and lead borate (2PbO . 2B(2)O(3)) solvents at 975 K. The experiments were carried out using both powdered single crystals grown by a flux technique and powders synthesized by precipitation. Formation enthalpies were derived from the drop-solution enthalpies for (RE)PO4, RE oxides, and P2O5. Enthalpies of formation for the (RE)PO4 compounds with respect to the oxides at 298 K become more negative with increasing RE3+ ionic radius; i.e., in going from ScPO4 (-209.8 +/- 1.0 kJ/mol), to LuPO4 (-263.9 +/- 1.9 kJ/mol), to LaPO4 (-321.4 +/- 1.6 kJ/mol). From structural considerations, a similar trend is expected for the isostructural RE vanadates and arsenates, as well as for the tetravalent actinide orthosilicates. C1 Univ Calif Davis, Dept Chem Engn & Mat Sci, Thermochem Facil, Davis, CA 95616 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Navrotsky, A (reprint author), Univ Calif Davis, Dept Chem Engn & Mat Sci, Thermochem Facil, Davis, CA 95616 USA. RI Ushakov, Sergey/C-5501-2008; Ushakov, Sergey/I-7278-2012; Boatner, Lynn/I-6428-2013; OI Boatner, Lynn/0000-0002-0235-7594; Ushakov, Sergey/0000-0002-8184-8884 NR 83 TC 136 Z9 138 U1 6 U2 49 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 2001 VL 16 IS 9 BP 2623 EP 2633 DI 10.1557/JMR.2001.0361 PG 11 WC Materials Science, Multidisciplinary SC Materials Science GA 470XZ UT WOS:000170898900027 ER PT J AU Aytug, T Kang, BW Cantoni, C Specht, ED Paranthaman, M Goyal, A Christen, DK Verebelyi, DT Wu, JZ Ericson, RE Thomas, CL Yang, CY Babcock, SE AF Aytug, T Kang, BW Cantoni, C Specht, ED Paranthaman, M Goyal, A Christen, DK Verebelyi, DT Wu, JZ Ericson, RE Thomas, CL Yang, CY Babcock, SE TI Growth and characterization of conductive SrRuO3 and LaNiO3 multilayers on textured Ni tapes for high-J(c) YBa2Cu3O7-delta coated conductors SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CRITICAL-CURRENT DENSITY; THIN-FILMS; SUPERCONDUCTING TAPES; BUFFER LAYERS; DEPOSITION; JUNCTIONS; STABILITY AB Power applications of high-temperature superconducting (HTS) coated conductors will require stabilization against thermal runaway. We have developed conductive buffer layers to electrically couple the HTS layer to the underlying metal substrate. The structure comprises the layer sequence of SrRuO3 (SRO) on LaNiO3 (LNO) on biaxially textured Ni substrates. We report baseline investigations of compatibility of SRO/LNO multilayer structure with processing of YBa2Cu3O7-delta (YBCO) and demonstrate biaxially textured YBCO films on conductively buffered Ni tapes. These YBCO coatings exhibit self-field J(c) values as high as 1.3 x 10(6) A/cm(2) at 77 K, and the entire structure (HTS + conductive buffers + metal substrate) shows good electrical connectivity. These results demonstrate that SRO/LNO buffer layers may provide a basis for stabilized coated conductors. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Amer Superconductor Corp, Westborough, MA 01581 USA. Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. 3M Co, St Paul, MN 55144 USA. Univ Wisconsin, Dept Mat Sci & Engn, Madison, WI 53706 USA. Univ Wisconsin, Ctr Appl Superconduct, Madison, WI 53706 USA. RP Aytug, T (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015; Cantoni, Claudia/G-3031-2013 OI Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531; Cantoni, Claudia/0000-0002-9731-2021 NR 22 TC 14 Z9 20 U1 1 U2 5 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 2001 VL 16 IS 9 BP 2661 EP 2669 DI 10.1557/JMR.2001.0365 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA 470XZ UT WOS:000170898900031 ER PT J AU Meldrum, A Honda, S White, CW Zuhr, RA Boatner, LA AF Meldrum, A Honda, S White, CW Zuhr, RA Boatner, LA TI Nanocrystals in crystalline silicon: Void formation and hollow particles SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID FREE-ENERGIES; CAVITIES; PHASE; NANOPARTICLES; BEHAVIOR; METALS; COPPER; AU AB Nanophase precipitates of CdS formed in amorphous SiO2 by ion implantation and thermal processing have recently been found to exhibit a "hollow-particle" or "shell-like" microstructure. The present investigations show that this hollow-particle microstructure can be reproduced for a variety of materials other than CdS, and these results provide new insight into the mechanisms responsible for the formation of hollow precipitates embedded in solid hosts. Various elemental metal nanocrystals were formed in (100)-oriented crystalline Si hosts by ion implantation coupled with thermal treatments in which the annealing parameters were varied to investigate the "hollow-particle" formation conditions. The results indicate that depending on the melting points and vapor pressure of the precipitates or on the initial state of the host material, several processes acting either independently or in concert can lead to hollow precipitate formation. First, the implantation of materials having a high vapor pressure, either at the implant temperature or when heated during annealing, can lead to the formation of cavities in the crystalline host. Hollow precipitates can then form by a partial filling and coating of the cavity walls by the implanted species in a diffusion-based gettering/ripening process. Internal void formation can also occur or be enhanced by volume contraction during cooling if the particle solidifies from a liquid phase. C1 Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Meldrum, A (reprint author), Univ Alberta, Dept Phys, Edmonton, AB T6G 2J1, Canada. RI Boatner, Lynn/I-6428-2013 OI Boatner, Lynn/0000-0002-0235-7594 NR 31 TC 17 Z9 17 U1 0 U2 5 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD SEP PY 2001 VL 16 IS 9 BP 2670 EP 2679 DI 10.1557/JMR.2001.0366 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA 470XZ UT WOS:000170898900032 ER PT J AU Balhorn, R Corzett, M Dolan, C Brewer, LR Lee, J Allen, MJ AF Balhorn, R Corzett, M Dolan, C Brewer, LR Lee, J Allen, MJ TI Packing and unpacking of DNA in sperm SO JOURNAL OF MEDICAL GENETICS LA English DT Meeting Abstract C1 Lawrence Livermore Natl Lab, Livermore, CA USA. RI Brewer, Laurence/G-4056-2012 NR 0 TC 0 Z9 0 U1 0 U2 2 PU BRITISH MED JOURNAL PUBL GROUP PI LONDON PA BRITISH MED ASSOC HOUSE, TAVISTOCK SQUARE, LONDON WC1H 9JR, ENGLAND SN 0022-2593 J9 J MED GENET JI J. Med. Genet. PD SEP PY 2001 VL 38 SU 1 MA SP21 BP S16 EP S16 PG 1 WC Genetics & Heredity SC Genetics & Heredity GA 473NV UT WOS:000171051200022 ER PT J AU Keener, WK Watwood, ME Schaller, KD Walton, MR Partin, JK Smith, WA Clingenpeel, SR AF Keener, WK Watwood, ME Schaller, KD Walton, MR Partin, JK Smith, WA Clingenpeel, SR TI Use of selective inhibitors and chromogenic substrates to differentiate bacteria based on toluene oxygenase activity SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE toluene oxygenases; aquifer bacteria; enzyme indicators; enzyme inhibitors; toluene ID CEPACIA G4; METHYLOCOCCUS-CAPSULATUS; PSEUDOMONAS-PUTIDA; ARVILLA MT-2; TRICHLOROETHYLENE; INACTIVATION; METABOLISM; CATABOLISM; ACETYLENE; ALKYNES AB In whole-cell studies. two alkynes. 1-pentyne and phenylacetylene. were selective, irreversible inhibitors of monooxygenase enzymes in catabolic pathways: that permit growth of bacteria on toluene. 1-Pentyne selectively inhibited growth of Burkholderia cepacia G4 (toluene 2-monooxygenase [T2MO] pathway) and B. pickettii PKO1 (toluene 3-monooxygenase [T3MO] pathway) on toluene. but did not inhibit growth of bacteria expressing other pathways. In further studies with strain G4. chromogenic transformation of alpha,alpha,alpha -Trifluoro-m-cresol (TFC) was irreversibly inhibited by 1-pentyne. but the presence of phenol prevented this inhibition. Transformation of catechol by G4 was unaffected by 1-pentyne. With respect to the various pathways and bacteria tested. phenylacetylene selectively inhibited growth of Pseudomonas mendocina KR1 (toluene 3-monooxygenase [T4MO] pathway) on toluene. but not on p-cresol. An Escherichia coli transformant expressing T4MO transformed indole or naphthalene in chromogenic reactions. but not after exposure to phenylacetylene. The naphthalene reaction remained diminished in phenylacetylene-treated cells relative to untreated cells after phenylacetylene was removed, indicating irreversible inhibition. These techniques were used to differentiate toluene-degrading isolates from an aquifer. Based on data generated with these indicators and inhibitors, along with results from Biolog analysis for sole carbon source oxidation. the groundwater isolates were assigned to eight separate groups, some of which apparently differ in their mode of toluene catabolism. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Idaho State Univ, Dept Biol Sci, Pocatello, ID 83209 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Watwood, ME (reprint author), Idaho State Univ, Dept Biol Sci, Pocatello, ID 83209 USA. OI Walton, Michelle/0000-0003-4169-4443; Clingenpeel, Scott/0000-0002-6619-6320 NR 29 TC 11 Z9 12 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7012 J9 J MICROBIOL METH JI J. Microbiol. Methods PD SEP PY 2001 VL 46 IS 3 BP 171 EP 185 DI 10.1016/S0167-7012(01)00266-4 PG 15 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA 454LZ UT WOS:000169975200001 PM 11438182 ER PT J AU Jensen, BD de Boer, MP Masters, ND Bitsie, F LaVan, DA AF Jensen, BD de Boer, MP Masters, ND Bitsie, F LaVan, DA TI Interferometry of actuated microcantilevers to determine material properties and test structure nonidealities in MEMS SO JOURNAL OF MICROELECTROMECHANICAL SYSTEMS LA English DT Article DE free-standing thin films; in situ characterization; mechanical properties; statistical accuracy assessments ID THIN-FILMS; MECHANICAL-PROPERTIES; FRICTION MEASUREMENT; MICROMACHINED BEAMS; FRACTURE STRENGTH; POLYSILICON FILMS; YOUNGS MODULUS; NANOINDENTATION; ADHESION; STRESSES AB By integrating interferometric deflection data from electrostatically actuated microcantilevers with a numerical finite difference model, we have developed a step-by-step procedure to determine values of Young's modulus while simultaneously quantifying nonidealities. The central concept in the methodology is that nonidealities affect the long-range deflections of the beams, which can be determined to near nanometer accuracy. Beam take-off angle, curvature and support post compliance are systematically determined. Young's modulus is then the only unknown parameter, and is directly found. We find an average value of Young's modulus for polycrystalline silicon of 164.3 GPa and a standard deviation of 3.2 GPa (+/-2%), reflecting data from three different support post designs. Systematic errors were assessed and may alter the average value by +/-5%. An independent estimate from grain orientation measurements yielded 163.4-164.4 GPa (the Voigt and Reuss bounds), in agreement with the step-by-step procedure. Other features of the test procedure include that it is rapid, nondestructive, verifiable and requires only a small area on the test chip. C1 Sandia Natl Labs, MEMS & Novel Silicon Sci & Technol Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Electromech Engn Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Mech Reliabil & Melting Dept, Albuquerque, NM 87185 USA. RP Jensen, BD (reprint author), Univ Michigan, Dept Mech Engn, Ann Arbor, MI 48109 USA. RI Jensen, Brian/B-3125-2008; LaVan, David/C-3943-2012; de Boer, Maarten/C-1525-2013 OI LaVan, David/0000-0002-1952-0028; de Boer, Maarten/0000-0003-1574-9324 NR 35 TC 87 Z9 91 U1 0 U2 14 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 USA SN 1057-7157 J9 J MICROELECTROMECH S JI J. Microelectromech. Syst. PD SEP PY 2001 VL 10 IS 3 BP 336 EP 346 DI 10.1109/84.946779 PG 11 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Instruments & Instrumentation; Physics, Applied SC Engineering; Science & Technology - Other Topics; Instruments & Instrumentation; Physics GA 470MN UT WOS:000170875900003 ER PT J AU Joly, AG Chen, W Roark, J Zhang, JZ AF Joly, AG Chen, W Roark, J Zhang, JZ TI Temperature dependence of up-conversion luminescence and photoluminescence of Mn2+ in ZnS : Mn2+ nanoparticles SO JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY LA English DT Article DE ZnS : Mn2+; nanoparticle; up-conversion; two-photon absorption; luminescence; doped semiconductor; temperature dependence; energy transfer ID ZNS NANOCLUSTERS; NANOCRYSTALS; SEMICONDUCTOR; SURFACE AB The photoluminescence (excited at both 300 nm and 383.5 nm) and up-conversion luminescence (excited at 767 nm) of the Mn2+ T-4(1)-->(6)A(1) transition in both bulk and ZnS:Mn2+ nanoparticles have been measured as a function of temperature. The Mn2+ emission spectra shift monotonically to longer wavelengths at lower temperatures, whereas the intensity change of the luminescence is more complex. The complicated temperature behavior is explained by considering the processes of nonradiation relaxation via phonon coupling, exciton thermal dissociation (binding energy), energy transfer, carrier trapping, and the temperature change of the absorption spectra. The fact that the temperature dependence of the 767 nm excited up-conversion luminescence is the same as the 383.5 nm excited photoluminescence in both bulk and nanoparticles supports the conclusion that the up-conversion luminescence is due to two-photon absorption. C1 Nomad Inc, Stillwater, OK 74074 USA. Pacific NW Natl Lab, WR Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Calif Santa Cruz, Dept Chem, Santa Cruz, CA 95064 USA. RP Chen, W (reprint author), Nomad Inc, 1024 S Innovat Way, Stillwater, OK 74074 USA. NR 22 TC 20 Z9 20 U1 4 U2 15 PU AMER SCIENTIFIC PUBLISHERS PI STEVENSON RANCH PA 25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA SN 1533-4880 J9 J NANOSCI NANOTECHNO JI J. Nanosci. Nanotechnol. PD SEP PY 2001 VL 1 IS 3 BP 295 EP 301 DI 10.1166/jnn.2001.049 PG 7 WC Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 529GK UT WOS:000174291500009 PM 12914066 ER PT J AU Thanos, PK Volkow, ND Freimuth, P Umegaki, H Ikari, H Roth, G Ingram, DK Hitzemann, R AF Thanos, PK Volkow, ND Freimuth, P Umegaki, H Ikari, H Roth, G Ingram, DK Hitzemann, R TI Overexpression of dopamine D2 receptors reduces alcohol self-administration SO JOURNAL OF NEUROCHEMISTRY LA English DT Article DE adenovirus; alcoholism; animal model; drinking preference; gene therapy; nucleus accumbens ID MEDIATED GENE-TRANSFER; NUCLEUS-ACCUMBENS; RAT STRIATUM; ETHANOL REINFORCEMENT; ALLELIC ASSOCIATION; PREFERRING RATS; CONSUMPTION; INITIATION; PREFERENCE; DRINKING AB The mechanism(s) underlying predisposition to alcohol abuse are poorly understood but may involve brain dopamine system(s). Here we used an adenoviral vector to deliver the dopamine D2 receptor (DRD2) gene into the nucleus accumbens of rats, previously trained to self-administer alcohol, and to assess if DRD2 levels regulated alcohol preference and intake. We show that increases in DRD2 (52%) were associated with marked reductions in alcohol preference (43%), and alcohol intake (64%) of ethanol preferring rats, which recovered as the DRD2, returned to baseline levels. In addition, this DRD2 overexpression similarly produced significant reductions in ethanol nonpreferring rats, in both alcohol preference (16%) and alcohol intake (75%). This is the first evidence that overexpression of DRD2 reduces alcohol intake and suggests that high levels of DRD2 may be protective against alcohol abuse. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Nagoya Univ, Sch Med, Dept Geriatr, Aichi, Japan. NIA, Ctr Gerontol Res, Baltimore, MD 21224 USA. Oregon Hlth & Sci Univ, Dept Behav Neurosci, Portland, OR 97201 USA. RP Thanos, PK (reprint author), Brookhaven Natl Lab, Dept Med, Bldg 490, Upton, NY 11973 USA. EM thanos@bnl.gov FU NIAAA NIH HHS [AA07574, AA11034] NR 56 TC 160 Z9 163 U1 1 U2 4 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0022-3042 J9 J NEUROCHEM JI J. Neurochem. PD SEP PY 2001 VL 78 IS 5 BP 1094 EP 1103 DI 10.1046/j.1471-4159.2001.00492.x PG 10 WC Biochemistry & Molecular Biology; Neurosciences SC Biochemistry & Molecular Biology; Neurosciences & Neurology GA 467MG UT WOS:000170707900017 PM 11553683 ER PT J AU Tomizawa, M Wen, ZM Chin, HL Morimoto, H Kayser, H Casida, JE AF Tomizawa, M Wen, ZM Chin, HL Morimoto, H Kayser, H Casida, JE TI Photoaffinity labeling of insect nicotinic acetylcholine receptors with a novel [H-3]azidoneonicotinoid SO JOURNAL OF NEUROCHEMISTRY LA English DT Article DE insecticides; insects; neonicotinoids; nicotinic acetylcholine receptor; photoaffinity labeling ID APHID MYZUS-PERSICAE; ALPHA-SUBUNITS; DROSOPHILA; ORGANIZATION; AFFINITY; CLONING AB The nicotinic acetylcholine receptor (nAChR) is a ligand-gated ion channel in the insect CNS and a target for major insecticides. Here we use photoaffinity labeling to approach the functional architecture of insect nAChRs. Two candidate 5-azido-6-chloropyridin-3-yl photoaffinity probes are evaluated for their receptor potencies: azidoneonicotinoid (AzNN) with an acyclic nitroguanidine moiety; azidodehydrothiacloprid. Compared to their non-azido parents, both probes are of decreased potencies at Drosophila (fruit fly) and Musca (housefly) receptors but AzNN retains full potency at the Myzus (aphid) receptor. [H-3]AzNN was therefore radio-synthesized at high specific activity (84 Ci/mmol) as a novel photoaffinity probe. [H-3]AzNN binds to a single high-affinity site in Myzus that is competitively inhibited by imidacloprid and nicotine and further characterized as to its pharmacological profile with various nicotinic ligands. [H-3]AzNN photoaffinity labeling of Myzus and Homalodisca (leafhopper) detects a single radiolabeled peak in each case displaceable with imidacloprid and nicotine and with molecular masses corresponding to similar to 45 and similar to 56 kDa, respectively. The photoaffinity-labeled receptor in both Drosophila and Musca has imidacloprid- and nicotine-sensitive profiles and migrates at similar to 66 kDa. These photoaffinity-labeled polypeptides are considered to be the insecticide-binding subunits of native insect nAChRs. C1 Univ Calif Berkeley, Environm Chem & Toxicol Lab, Dept Environm Sci Policy & Management, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Natl Tritium Labeling Facil, Berkeley, CA USA. Syngenta Crop Protect AG, Res & Technol, Basel, Switzerland. RP Casida, JE (reprint author), Univ Calif Berkeley, Environm Chem & Toxicol Lab, Dept Environm Sci Policy & Management, 114 Wellman Hall, Berkeley, CA 94720 USA. FU NCRR NIH HHS [P41 RR 01237]; NIEHS NIH HHS [R01 ES08424] NR 26 TC 18 Z9 20 U1 0 U2 3 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0022-3042 J9 J NEUROCHEM JI J. Neurochem. PD SEP PY 2001 VL 78 IS 6 BP 1359 EP 1366 DI 10.1046/j.1471-4159.2001.00518.x PG 8 WC Biochemistry & Molecular Biology; Neurosciences SC Biochemistry & Molecular Biology; Neurosciences & Neurology GA 474LF UT WOS:000171107900017 PM 11579144 ER PT J AU Ayers, MR Hunt, AJ AF Ayers, MR Hunt, AJ TI Observation of the aggregation behavior of silica sols using laser speckle contrast measurements SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID LIGHT-SCATTERING; SURFACE-ROUGHNESS; GEL TRANSITION AB We report on a new optical method to observe the onset of aggregation in alcoholic tetraethoxysilane (TEOS) sols using laser speckle contrast measurements. The contrast in a speckle image produced by coherent light provides information about the internal contrast of the medium being studied. For silica sols, changing the amount of acid or base catalyst was the most important factor in determining the aggregation behavior of the sol. We investigated this effect by varying the TEOS/base ratio by a factor of 6. This shifted the onset of aggregation as determined by speckle contrast from similar to 46% of the gel time for the lowest amount of base to similar to 74%,, for the highest. Conversely, varying TEOS/acid ratio by a factor of 3, shifted the onset of aggregation from similar to 74% of the gel time for the lowest amount of acid to similar to 64%, for the highest. Measurements of this type provide information that can be used to test models of sol aggregation and gel formation. (C) 2001 Published by Elsevier Science B.V. C1 EO Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Hunt, AJ (reprint author), EO Lawrence Berkeley Natl Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 18 TC 9 Z9 9 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 2001 VL 290 IS 2-3 BP 122 EP 128 DI 10.1016/S0022-3093(01)00696-2 PG 7 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 473VB UT WOS:000171068000004 ER PT J AU Sordelet, DJ Kramer, MJ Besser, MF Rozhkova, E AF Sordelet, DJ Kramer, MJ Besser, MF Rozhkova, E TI Time-resolved studies of Ti34-xCu47Zr11Ni8Six metallic glass devitrification using high temperature X-ray powder diffraction SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID RIETVELD REFINEMENT; FORMING ALLOY; SYNCHROTRON AB Time-resolved devitrification studies of Ti34-xCu47Zr11Ni8Six, metallic glasses were performed using a recently developed high temperature furnace in a Debye-Scherrer geometry. Samples included powders produced by high pressure gas atomization and surface coatings deposited by air plasma spraying. Synchrotron radiation at the Advanced Photon Source at Argonne National Laboratory was used to follow the devitrification of samples during heating at 40 K min(-1) between 623 and 1073 K. The crystallization behavior observed with structural diffraction data compare well with results from thermal analysis using differential scanning calorimetery, At 1073 K, these amorphous alloys evolve to a four phase microstructure which includes phases that appear to be closely related to Cu51Zr14, CuTi and Cu2TiZr. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ, Dept Mech Engn, Ames, IA 50011 USA. US DOE, Ames Lab, Ames, IA 50011 USA. RP Sordelet, DJ (reprint author), Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. NR 8 TC 21 Z9 21 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD SEP PY 2001 VL 290 IS 2-3 BP 163 EP 172 DI 10.1016/S0022-3093(01)00819-5 PG 10 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA 473VB UT WOS:000171068000008 ER PT J AU Strachan, DM AF Strachan, DM TI Glass dissolution: testing and modeling for long-term behavior SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT International Topical Workshop on Glass in its Disposal Environment CY APR 11-14, 2000 CL BRUGGE, BELGIUM SP Belgian Agcy Radioact Waste & Enriched Fissile Mat, Int Atom Energy Agcy ID BOROSILICATE GLASS AB The basic concepts of thermodynamics and kinetics are discussed in relationship to glass dissolution testing. While it seems like these subjects are too basic to be discussed in a journal article. it is often the case that we forget these concepts when planning and designing dissolution tests and interpreting the results that come from these tests. The possible connection between the composition of the dissolving glass and its long-term behavior is discussed. Results from a preliminary study suggest that the aluminum content of a glass is important to its long-term behavior. The formation of a zeolite can cause the glass dissolution rate to increase under certain conditions that can be modeled. Results indicate that complex glasses can be modeled with a glass containing as little as six components. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Strachan, DM (reprint author), Pacific NW Natl Lab, 902 Battelle Blvd,MSIN K6-24, Richland, WA 99352 USA. NR 19 TC 27 Z9 28 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 2001 VL 298 IS 1-2 BP 69 EP 77 DI 10.1016/S0022-3115(01)00572-4 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 474LD UT WOS:000171107600010 ER PT J AU Wicks, GG AF Wicks, GG TI US field testing programs and results SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT International Topical Workshop on Glass in its Disposal Environment CY APR 11-14, 2000 CL BRUGGE, BELGIUM SP Belgian Agcy Radioact Waste & Enriched Fissile Mat, Int Atom Energy Agcy AB The US has been active in four major international in situ or field testing programs over the past two decades. involving the burial of simulated high-level waste forms and package components. These joint international efforts include: (1) burial of over 100 simulated Savannah River Site (SRS) high-level waste glass samples in the granite site at Stripa in Sweden. (2) burial of SRS glasses in clay at Mol, Belgium, (3) in situ testing of SRS waste forms and natural glass analogs in limestone at Ballidon in the UK. and (4) field testing of almost 2000 SRS and international waste form samples and package components in the salt site at the Waste Isolation Pilot Plant (WIPP) in the US. These programs are designed to supplement laboratory testing studies in order to obtain the most complete and realistic picture possible of waste glass behavior under realistic repository-relevant conditions. Waste glass performance thus far has been seen to be very good, and even better in the field than would be predicted by many so-called standardized laboratory leaching tests. Published by Elsevier Science B.V. C1 Westinghouse Savannah River Co, Savannah River Technol Ctr, Aiken, SC 29802 USA. RP Wicks, GG (reprint author), Westinghouse Savannah River Co, Savannah River Technol Ctr, Bldg 773-A,B-129, Aiken, SC 29802 USA. NR 28 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 2001 VL 298 IS 1-2 BP 78 EP 85 DI 10.1016/S0022-3115(01)00617-1 PG 8 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 474LD UT WOS:000171107600011 ER PT J AU McGrail, BP Bacon, DH Icenhower, JP Mann, FM Puigh, RJ Schaef, HT Mattigod, SV AF McGrail, BP Bacon, DH Icenhower, JP Mann, FM Puigh, RJ Schaef, HT Mattigod, SV TI Near-field performance assessment for a low-activity waste glass disposal system: laboratory testing to modeling results SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article; Proceedings Paper CT International Topical Workshop on Glass in its Disposal Environment CY APR 11-14, 2000 CL BRUGGE, BELGIUM SP Belgian Agcy Radioact Waste & Enriched Fissile Mat, Int Atom Energy Agcy ID ALTERATION KINETICS; NUCLEAR GLASS; DISSOLUTION; RATES; CONSTRAINTS; AFFINITY; TERM; AL AB Reactive chemical transport simulations of glass corrosion and radionuclide release from a low-activity waste (LAW) disposal system were conducted out to times in excess of 20 000 yr with the subsurface transport over reactive multiphases (STORM) code. Time and spatial dependence of glass corrosion rate, secondary phase formation, pH, and radionuclide concentration were evaluated. The results show low release rates overall for the LAW glasses such that performance objectives for the site will be met by a factor of 20 or more. Parameterization of the computer model was accomplished by combining direct laboratory measurements, literature data (principally thermodynamic data), and parameter estimation methods. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Appl Geol & Geochem Dept, Richland, WA 99352 USA. CH2M Hill Inc, Richland, WA 99352 USA. Fluor Fed Serv, Richland, WA 99352 USA. RP McGrail, BP (reprint author), Pacific NW Natl Lab, Appl Geol & Geochem Dept, 902 Battelle Blvd,POB 999,MS K6-81, Richland, WA 99352 USA. RI Icenhower, Jonathan/E-8523-2011 NR 39 TC 31 Z9 32 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 2001 VL 298 IS 1-2 BP 95 EP 111 DI 10.1016/S0022-3115(01)00576-1 PG 17 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 474LD UT WOS:000171107600013 ER PT J AU Richmann, MK Reed, DT Kropf, AJ Aase, SB Lewis, MA AF Richmann, MK Reed, DT Kropf, AJ Aase, SB Lewis, MA TI EXAFS/XANES studies of plutonium-loaded sodalite/glass waste forms SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID SIZE; SALT AB A sodalite/glass ceramic waste form is being developed to immobilize highly radioactive nuclear wastes in chloride form, as part of an electrochemical cleanup process. Two types of simulated waste forms were studied: where the plutonium was alone in an LiCl/KCl matrix and where simulated fission-product elements were added representative of the electrometallurgical treatment process used to recover uranium from spent nuclear fuel also containing plutonium and a variety of fission products. Extended X-ray absorption fine structure spectroscopy (EXAFS) and X-ray absorption near-edge spectroscopy (XANES) studies were performed to determine the location, oxidation state, and particle size of the plutonium within these waste form samples. Plutonium was found to segregate as plutonium(IV) oxide with a crystallite size of at least 4.8 mn in the non-fission-element case and 1.3 nm with fission elements present. No plutonium was observed within the socialite in the waste form made from the plutonium-loaded LiCl/KCl eutectic salt. Up to 35% of the plutonium in the waste form made from the plutonium-loaded simulated fission-product salt may be segregated with a heavy-element nearest neighbor other than plutonium or occluded internally within the socialite lattice. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Richmann, MK (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI ID, MRCAT/G-7586-2011; Kropf, Arthur/B-8665-2015 NR 20 TC 7 Z9 7 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 2001 VL 297 IS 3 BP 303 EP 312 DI 10.1016/S0022-3115(01)00637-7 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 469YE UT WOS:000170843000009 ER PT J AU Sheldon, RI AF Sheldon, RI TI An estimate of the high temperature, metal rich phase boundary of plutonium sesquioxide SO JOURNAL OF NUCLEAR MATERIALS LA English DT Letter ID SYSTEM AB The composition of the metal rich phase boundary of plutonium sesquioxide has been estimated at 1400 K by comparing the calculated, equilibrium pressure of Pu(g) over the solid solution range of the sesquioxide with the reported Pu(g) pressure over the mutually saturated system, Pu(liquid, O-2 saturated) + < Pu2O3-x> (hex). The Pu(g) pressure at the previously recommended metal rich phase boundary is shown to be low by a factor of nearly 3000. The newly estimated metal rich phase boundary results in a homogeneity range for the sesquioxide that is larger by a factor of 1.8. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Los Alamos Natl Lab, Div Nucl Mat Technol, Los Alamos, NM 87545 USA. RP Sheldon, RI (reprint author), Los Alamos Natl Lab, Div Nucl Mat Technol, POB 1663, Los Alamos, NM 87545 USA. NR 9 TC 1 Z9 1 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD SEP PY 2001 VL 297 IS 3 BP 358 EP 360 DI 10.1016/S0022-3115(01)00638-9 PG 3 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA 469YE UT WOS:000170843000016 ER PT J AU Pollycove, M AF Pollycove, M TI Biologic responses to low doses of ionizing radiation: Detriment versus hormesis Part 2. Dose responses of organisms SO JOURNAL OF NUCLEAR MEDICINE LA English DT Editorial Material ID TOTAL-BODY IRRADIATION; NON-HODGKINS-LYMPHOMA; DNA-REPAIR GENES; LUNG-CANCER; HUMAN-LYMPHOCYTES; OXIDATIVE STRESS; NEOPLASTIC TRANSFORMATION; ENVIRONMENTAL RADIATION; ADAPTIVE RESPONSE; MOLECULAR-BIOLOGY C1 US Nucl Regulatory Commiss, Bethesda, MD USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Pollycove, M (reprint author), US Nucl Regulatory Commiss, Bethesda, MD USA. NR 89 TC 32 Z9 36 U1 0 U2 6 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD SEP PY 2001 VL 42 IS 9 BP 26N EP + PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 469XH UT WOS:000170841000003 PM 11554390 ER PT J AU Knapp, FF Spencer, RH Kropp, J AF Knapp, FF Spencer, RH Kropp, J TI Invited commentary - Intravascular radiation therapy with radioactive liquid-filled balloons for inhibition of restenosis after angioplasty: A new opportunity for nuclear medicine? SO JOURNAL OF NUCLEAR MEDICINE LA English DT Editorial Material ID RE-188; GENERATOR; CATHETER C1 Oak Ridge Natl Lab, Nucl Med Grp, Oak Ridge, TN 37831 USA. Univ Tennessee Hosp, Knoxville Cardiovasc Grp PC, Knoxville, TN USA. Tech Univ Dresden, Univ Hosp, D-8027 Dresden, Germany. RP Knapp, FF (reprint author), Oak Ridge Natl Lab, Nucl Med Grp, Bldg 4501,MS6229,POB 2008, Oak Ridge, TN 37831 USA. NR 40 TC 14 Z9 16 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 USA SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD SEP PY 2001 VL 42 IS 9 BP 1384 EP 1387 PG 4 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 469XH UT WOS:000170841000026 PM 11535729 ER PT J AU Nadiga, BT Luce, BP AF Nadiga, BT Luce, BP TI Global bifurcation of Shilnikov type in a double-gyre ocean model SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID WIND-DRIVEN CIRCULATION; LOW-FREQUENCY VARIABILITY; MULTIPLE EQUILIBRIA; HOMOCLINIC ORBITS; BAROTROPIC MODEL; FLOWS; DYNAMICS; ATTRACTORS; SYMMETRY; BEHAVIOR AB The dynamics of an idealized wind-driven double-gyre circulation in an ocean basin are studied from a dynamical systems point of view in an effort to better understand its variability. While previous analyses of this circulation have mostly dealt with local bifurcations of steady states and limit cycles, this study demonstrates the importance of considering global bifurcations as well. In one case, a coherent picture of the global dynamics spanning a range of parameters from where there are only stable steady-state solutions to where there is chaotic eddy shedding is presented. A simple but novel use of power spectra along with dynamical projections of the dynamics suggests that just beyond the regime in which there are only stable steady states, the system exhibits a complicated global bifurcation known as the "Shitnikov phenomenon." C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Nadiga, BT (reprint author), Los Alamos Natl Lab, Div Theoret, MS B-296, Los Alamos, NM 87545 USA. EM balu@lanl.gov NR 40 TC 41 Z9 41 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 EI 1520-0485 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 2001 VL 31 IS 9 BP 2669 EP 2690 DI 10.1175/1520-0485(2001)031<2669:GBOSTI>2.0.CO;2 PG 22 WC Oceanography SC Oceanography GA 473QZ UT WOS:000171060600009 ER PT J AU Sun, S Bleck, R AF Sun, S Bleck, R TI Thermohaline circulation studies with an Isopycnic Coordinate Ocean Model SO JOURNAL OF PHYSICAL OCEANOGRAPHY LA English DT Article ID GREENLAND-SCOTLAND RIDGE; ANTARCTIC BOTTOM WATER; NORTH-ATLANTIC; DEEP-WATER; INDIAN-OCEAN; TRANSPORT; EXCHANGE; THROUGHFLOW; ATMOSPHERE; FLOW AB The thermohaline circulation (THC) in a 1000-yr near-global numerical simulation using the Miami Isopycnic Coordinate Ocean Model is analyzed and compared to observations. The model, driven by observed monthly atmospheric climatology, uses potential density referenced to 2000 M (sigma (2)) as the vertical coordinate and accounts for compressibility (thermobaricity) effects. Examination of the three-dimensional mass flux field reveals that the model comes fairly close to quantitatively reproducing a number of global and basin-scale circulation features, such as the vertical-meridional overturning rate in the three major basins, the meridional heat flux, and the transport through the major passages. Methods are presented that allow the construction of composite diagrams revealing quantitative regional aspects of the modeled circulation in potential density space. The diagrams reveal many features of the modeled THC that adhere to observations. the most noticeable shortcoming being a weaker-than-observed northward penetration of bottom water into the three major basins caused by insufficient production of Antarctic Bottom Water. C1 NASA, Goddard Inst Space Studies, New York, NY 10025 USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP Sun, S (reprint author), NASA, Goddard Inst Space Studies, 2880 Broadway, New York, NY 10025 USA. RI Sun, Shan/H-2318-2015 NR 54 TC 18 Z9 18 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0022-3670 J9 J PHYS OCEANOGR JI J. Phys. Oceanogr. PD SEP PY 2001 VL 31 IS 9 BP 2761 EP 2782 DI 10.1175/1520-0485(2001)031<2761:TCSWAI>2.0.CO;2 PG 22 WC Oceanography SC Oceanography GA 473QZ UT WOS:000171060600014 ER PT J AU Choueiri, EY Ziemer, JK AF Choueiri, EY Ziemer, JK TI Quasi-steady magnetoplasmadynamic thruster performance database SO JOURNAL OF PROPULSION AND POWER LA English DT Article; Proceedings Paper CT 34th Conference of the AIAA on Joint Propulsion CY JUL 13-16, 1998 CL CLEVELAND, OHIO ID MPD THRUSTER AB The performance of a coaxial, gas-fed, self-field, quasi-steady pulsed magnetoplasmadynamic thruster (MPDT) was measured using a swinging gate thrust stand equipped with a laser interferometer and an rf proximity transducer. Careful calibration of the thrust stand and other diagnostics ensured that the measurement errors, barring the effects of fluctuations in the discharge voltage, are well below 2%. The measurements were carried out for various mass flow rates, ranging between 0.5 and 6 g/s and for four propellant gases: argon, xenon, hydrogen, and deuterium. The data set can be interpreted to describe both the performance of steady-state high-power (multimegawatt) MPDTs and quasi-steady pulsed MPDTs that can operate at low spacecraft bus power. The results were curve fit and compiled into a performance database that is intended as a data source for system or mission analysis as well as for the validation of analytical and numerical models of the MPDT. C1 Princeton Univ, Elect Prop & Plasma Dynam Lab, Princeton, NJ 08544 USA. Princeton Univ, Dept Mech & Aerosp Engn, Appl Phys Grp, Princeton, NJ 08544 USA. Princeton Univ, Dept Astrophys Sci, Program Plasma Phys, Princeton, NJ 08544 USA. RP Choueiri, EY (reprint author), Princeton Univ, Elect Prop & Plasma Dynam Lab, Princeton, NJ 08544 USA. NR 32 TC 12 Z9 12 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD SEP-OCT PY 2001 VL 17 IS 5 BP 967 EP 976 DI 10.2514/2.5857 PG 10 WC Engineering, Aerospace SC Engineering GA 472VM UT WOS:000171005700003 ER PT J AU Owen, LA Gualtieri, L Finkel, RC Caffee, MW Benn, DI Sharma, MC AF Owen, LA Gualtieri, L Finkel, RC Caffee, MW Benn, DI Sharma, MC TI Cosmogenic radionuclide dating of glacial landforms in the Lahul Himalaya, northern India: defining the timing of Late Quaternary glaciation SO JOURNAL OF QUATERNARY SCIENCE LA English DT Article DE cosmogenic radionuclide dating; glaciation; Himalayas; Late Quaternary; South Asian summer monsoon ID RADIOCARBON AGE CALIBRATION; NORTHWESTERN HIMALAYA; ICE-CORE; PRODUCTION-RATES; MONSOON; BE-10; CLIMATE; HISTORY; INSTABILITY; NUCLIDES AB The timing of glaciation in the Lahul Himalaya of northern India was ascertained using the concentrations of cosmogenic Be-10 and Al-26 from boulders on moraines and drumlins, and from glacially polished bedrock surfaces. Five glacial stages were identified: Sonapani I and II, Kulti, Batal and Chandra. Of these, cosmogenic exposure ages were obtained on samples representative of the Batal and Kulti glacial cycles. Stratigraphical relationships indicate that the Sonapani I and II are younger. No age was obtained for the Chandra glacial advance. Batal Glacial Stage deposits are found throughout the valley, indicating the presence of an extensive valley glacial system. During the Kulti Stage, glaciers advanced ca. 10 km beyond their current positions. Moraines produced during the Batal Stage, ca. 12-15.5 ka, are coeval with the Northern Hemisphere Late-glacial Interstadial (Bolling/Allerod). Deglaciation of the Batal Glacial Stage was completed by ca. 12 ka and was followed by the Kulti Glacial Stage during the early Holocene, at ca. 10-11.4 ka. On millennial time-scales, glacier oscillations in the Lahul Himalaya apparently reflect periods of positive mass-balance coincident with times of increased insolation. During these periods the South Asian summer monsoon strengthened and/or extended its influence further north and west, thereby enhancing high-altitude summer snowfall. Copyright (C) 2001 John Wiley & Sons, Ltd. C1 Univ Calif Riverside, Dept Earth Sci, Riverside, CA 92521 USA. Univ Washington, Quaternary Res Ctr, Seattle, WA 98195 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Univ St Andrews, Sch Geog & Geosci, St Andrews KY16 9ST, Fife, Scotland. Jawaharlal Nehru Univ, Ctr Study Reg Dev, New Delhi 110067, India. RP Owen, LA (reprint author), Univ Calif Riverside, Dept Earth Sci, Riverside, CA 92521 USA. RI Caffee, Marc/K-7025-2015 OI Caffee, Marc/0000-0002-6846-8967 NR 50 TC 89 Z9 94 U1 2 U2 5 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0267-8179 J9 J QUATERNARY SCI JI J. Quat. Sci. PD SEP PY 2001 VL 16 IS 6 BP 555 EP 563 DI 10.1002/jqs.621 PG 11 WC Geosciences, Multidisciplinary; Paleontology SC Geology; Paleontology GA 479BF UT WOS:000171383500005 ER PT J AU Parr, AC West, JB King, MRF Ueda, K Dehmer, PM Dehmer, JL AF Parr, AC West, JB King, MRF Ueda, K Dehmer, PM Dehmer, JL TI Vibrational branching ratios and asymmetry parameters in the photoionization of CO2 in the region between 650 angstrom and 840 angstrom SO JOURNAL OF RESEARCH OF THE NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY LA English DT Article DE asymmetry; autoionization; branching ratios; parameters; photoelectron spectra ID PHOTOELECTRON ANGULAR-DISTRIBUTIONS; CARBON-DIOXIDE; AUTOIONIZATION; RESONANCES; MOLECULES; SPECTRUM; SPECTROSCOPY; IONIZATION; RADIATION; STATES AB The vibrational branching ratios and asymmetry parameters for CO2 have been determined in the wavelength region of 650 Angstrom to near the ionization onset at about 840 Angstrom. The study was performed using synchrotron radiation from the Daresbury storage ring that was dispersed with a 5 m grating monochomator that afforded resolution of 0.1 Angstrom to 0.2 Angstrom. This resolution allowed the study of the branching ratios and asymmetry parameters with enough detail to see the changes in the parameters within the pronounced autoionization structure in CO2 in this wavelength region. While the electron spectrometer resolution was not sufficient to resolve the spin orbit and Renner-Teller splitting in the photoelectron spectra, we are able to fit the data with a model that identifies the major structure in terms of the symmetric stretch and elements of the asymmetric stretch and bending modes. A calculation of the expected relative vibrational excitations based upon the Franck-Condon principle clearly showed non-Franck-Condon behavior in some of the vibrational-electronic transitions. C1 Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. SERC, Daresbury Lab, Warrington WA4 4AD, Cheshire, England. Tohoku Univ, Sci Measurements Res Inst, Sendai, Miyagi 980, Japan. US DOE, Off Basic Energy Sci, Germantown, MD 20874 USA. Natl Sci Fdn, Arlington, VA 22230 USA. RP Parr, AC (reprint author), Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. NR 43 TC 4 Z9 4 U1 0 U2 15 PU US GOVERNMENT PRINTING OFFICE PI WASHINGTON PA SUPERINTENDENT DOCUMENTS,, WASHINGTON, DC 20402-9325 USA SN 1044-677X J9 J RES NATL INST STAN JI J. Res. Natl. Inst. Stand. Technol. PD SEP-OCT PY 2001 VL 106 IS 5 BP 795 EP 822 DI 10.6028/jres.106.038 PG 28 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 490JB UT WOS:000172047800003 PM 27500048 ER PT J AU Roy, CJ Blottner, FG AF Roy, CJ Blottner, FG TI Assessment of one- and two-equation turbulence models for hypersonic transitional flows SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID K-EPSILON MODEL; BOUNDARY-LAYERS; ACCURACY AB One- and two-equation turbulence models are examined for hypersonic perfect- and real-gas flows with laminar, transitional, and turbulent flow regions. These models were generally developed for incompressible flows, and the extension to the hypersonic flow regime is discussed. In particular, the compressible formulation of the turbulence diffusion term for one-equation models is examined. For the Spalart-Allmaras model, the standard method for forcing transition at a specified location is found to be inadequate for hypersonic flows. An alternative transition method is proposed and evaluated for a Mach 8 flat plate test case. This test case is also used to evaluate three different two-equation turbulence models: a low-Reynolds-number k-epsilon model, the Menter k-omega formulation, and the Wilcox k-omega model. These one- and two-equation models are then applied to the Mach 20 Reentry F flight vehicle. The Spalart-Allmaras model and both k-omega formulations are found to provide reasonable agreement with the flight data for heat flux, whereas the Baldwin-Barth and low-Reynolds-number k-epsilon models overpredict the turbulent heating rates by a factor of two. Careful attention is given to the numerical accuracy of the solutions in the areas of both iterative and grid convergence. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Roy, CJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. RI Roy, Christopher/C-5427-2013 NR 33 TC 13 Z9 17 U1 0 U2 5 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 USA SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD SEP-OCT PY 2001 VL 38 IS 5 BP 699 EP 710 DI 10.2514/2.3755 PG 12 WC Engineering, Aerospace SC Engineering GA 482JQ UT WOS:000171573400007 ER PT J AU Traxler, KW Norcum, MT Hainfeld, JF Carlson, GM AF Traxler, KW Norcum, MT Hainfeld, JF Carlson, GM TI Direct visualization of the calmodulin subunit of phosphorylase kinase via electron microscopy following subunit exchange SO JOURNAL OF STRUCTURAL BIOLOGY LA English DT Article DE calmodulin; Nanogold; phosphorylase kinase ID RABBIT-SKELETAL-MUSCLE; MOLECULAR-BASIS; PROTEIN-KINASE; GAMMA-SUBUNIT; BETA-SUBUNITS; ALPHA-SUBUNIT; CDNA CLONING; ACTIVATION; IDENTIFICATION; DELTA AB Calmodulin is a tightly bound, intrinsic subunit (delta) of the hexadecameric phosphorylase-b kinase holoenzyme, (alpha beta gamma delta)(4). To introduce specifically labeled calmodulin into the phosphorylase-b kinase complex for its eventual visualization by electron microscopy, we have developed a method for rapidly exchanging exogenous calmodulin for the intrinsic delta subunit. This method exploits previous findings that low concentrations of urea in the absence of Ca2+ ions cause the specific dissociation of only the delta subunit from the holoenzyme [Paudel, H. K., and Carlson, G. M. (1990) Biochem. J. 268, 393-399]. In the current study, phosphorylase-b kinase was incubated with excess exogenous calmodulin and a threshold concentration of urea to promote exchange of its delta subunit with the exogenous calmodulin. Size exclusion HPLC was then used to remove the excess calmoduiin from the holoenzyme containing exchanged delta subunits. Using metabolically labeled [S-35]calmodulin to allow quantification and optimization of exchange conditions, we achieved exchange of approximately 10% of all delta subunits within 1 h, with the exchanged holoenzyme retaining full catalytic activity. Calmodulins derivatized with Nanogold for visualization by scanning transmission electron microscopy were then exchanged for delta, which for the first time allowed localization of the delta subunit within the bridged, bilobal phosphorylase b kinase holoenzyme complex. The delta subunits were determined to be near the edge of the lobes, just distal to the interlobal bridges and proximal to a previously identified region of the enzyme's catalytic gamma subunit. (C) 2001 Elsevier Science. C1 Univ Missouri, Sch Biol Sci, Div Mol Biol & Biochem, Kansas City, MO 64110 USA. Bemidji State Univ, Dept Chem, Bemidji, MN 56601 USA. Univ Mississippi, Med Ctr, Dept Biochem, Jackson, MS 39216 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Carlson, GM (reprint author), Univ Missouri, Sch Biol Sci, Div Mol Biol & Biochem, 503 Biol Sci Bldg,5100 Rockhill Rd, Kansas City, MO 64110 USA. FU NIDDK NIH HHS [DK32953] NR 31 TC 18 Z9 18 U1 1 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1047-8477 J9 J STRUCT BIOL JI J. Struct. Biol. PD SEP PY 2001 VL 135 IS 3 BP 231 EP 238 DI 10.1006/jsbi.2001.4411 PG 8 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 502CA UT WOS:000172725100001 PM 11722163 ER PT J AU Habelitz, S Marshall, SJ Marshall, GW Balooch, M AF Habelitz, S Marshall, SJ Marshall, GW Balooch, M TI The functional width of the dentino-enamel junction determined by AFM-Based nanoscratching SO JOURNAL OF STRUCTURAL BIOLOGY LA English DT Article DE atomic force microscopy; nanoindentation; nanoscratch testing; friction coefficient; dentino-enamel junction; tooth ID ELASTIC-MODULUS; MECHANICAL-PROPERTIES; ELECTRON-MICROSCOPY; HUMAN TEETH; NANOINDENTATION; HARDNESS; INDENTATION; FRICTION; FRACTURE; ADHESION AB The dentino-enamel junction (DEJ) constitutes a structurally unique interphase uniting two mineralized tissues with very different matrix composition and physical properties. Its excellent biomechanical properties have drawn interest as a biomimetic model for joining dissimilar materials. In order to characterize the functional width of the DEJ, nanoscratching experiments were performed on human third molars. Friction coefficients of enamel, of dentin, and at the DEJ were obtained with a nanoscratch tester attached to an atomic force microscope (AFM). Normal loads in the range of 50 to 600 muN were applied to a spherical diamond indenter (r = 10 mum), which was driven 10 mum across the sample surface, recording the lateral force. Imaging with an AFM facilitated exact positioning of the scratches. The friction coefficient of intertubular dentin was 0.31 +/- 0.05, significantly above the coefficient of enamel of 0.14 +/- 0.02. The increased friction of dentin is attributed to the higher content of organic phases. Scratches performed across the interphase between enamel and dentin showed a sharp monotonic change in the friction coefficient. The average width of the slope between the friction coefficients of dentin and enamel was 2.0 +/- 1.1 mum and is assumed to represent the functional width of the dentino-enamel junction. The effect of the scalloped structure of the DEJ on its functional width as determined by mechanical testing is discussed. (C) 2001 Elsevier Science. C1 Univ Calif San Francisco, Dept Prevent & Restorat Dent Sci, San Francisco, CA 94143 USA. Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94550 USA. RP Habelitz, S (reprint author), Univ Calif San Francisco, Dept Prevent & Restorat Dent Sci, 707 Parnassus Ave,D-2250, San Francisco, CA 94143 USA. FU NIDCR NIH HHS [DE13029] NR 34 TC 46 Z9 48 U1 4 U2 14 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1047-8477 J9 J STRUCT BIOL JI J. Struct. Biol. PD SEP PY 2001 VL 135 IS 3 BP 294 EP 301 DI 10.1006/jsbi.2001.4409 PG 8 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 502CA UT WOS:000172725100007 PM 11722169 ER PT J AU Shastri, SD Zambianchi, P Mills, DM AF Shastri, SD Zambianchi, P Mills, DM TI Dynamical diffraction of ultrashort X-ray free-electron laser pulses SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE X-ray free-electron lasers; X-ray sources; X-ray optics; dynamical diffraction AB Calculations are presented for the femtosecond time-evolution of intensities of beams diffracted by perfect Bragg crystals illuminated with radiation expected from X-ray free-electron lasers (XFELs) operating through the self-amplified spontaneous emission (SASE) process. After examining the case of transient diffraction of an electromagnetic delta-function impulse through flat, single- and double-crystal monochromators, the propagation of a 280 fs-duration SASE XFEL pulse of 8 keV photons through the same optics is discussed. The alteration of the sub-femtosecond spiky microbunched temporal structure of the XFEL pulse after it passes through the system is shown for both low-order (broad bandwidth) and high-order (narrow bandwidth) crystal reflections. Finally, the shot-to-shot statistical fluctuations of the integrated diffracted intensity is simulated. Implications of these results for XFEL applications are addressed. C1 Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. RP Shastri, SD (reprint author), Argonne Natl Lab, Adv Photon Source, Argonne, IL 60439 USA. NR 10 TC 32 Z9 33 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD SEP PY 2001 VL 8 BP 1131 EP 1135 DI 10.1107/S0909049501012390 PN 5 PG 5 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 466MC UT WOS:000170648500002 ER PT J AU Tajiri, G Lee, WK Fernandez, P Mills, D Assoufld, L Amirouche, F AF Tajiri, G Lee, WK Fernandez, P Mills, D Assoufld, L Amirouche, F TI Nonlinear thermal-distortion predictions of a silicon monochromator using the finite element method SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE finite element method; silicon monochromators; nonlinear thermal distortions ID PERFORMANCE AB Silicon crystal monochromators at cryogenic temperatures have been used with great success at third-generation synchrotron radiation sources. At the Advanced Photon Source the unique characteristics of silicon at liquid nitrogen temperatures (80 K) have been leveraged to significantly reduce the thermally induced distortions on beamline monochromators. Finite element simulations of the nonlinear (temperature-dependent material properties) thermal stress problem were performed and compared with the experimental measurements. Several critical finite element modeling considerations are discussed for their role in accurately predicting the highly coupled thermal and structural response of the optical component's surface distortion to the high thermal heat flux. Once an understanding of the effects of (i) local element mesh size, (ii) area/surface heat flux versus volumetric heat generation, and (iii) uniform volumetric absorbed power versus a depth-dependent absorbed power, a final series of simulations was performed. Depending on the estimated convection heat-transfer coefficient, the final refined finite element model's predictions correlated well with the experimental measurements. In general, the use of the finite element method in predicting the overall thermal and structural behavior of the surface of the optical components with a high heat flux was shown to be quite effective. C1 Argonne Natl Lab, Adv Photon Source, User Program Div, Argonne, IL 60439 USA. Univ Illinois, Dept Mech Engn, Chicago, IL 60607 USA. RP Lee, WK (reprint author), Argonne Natl Lab, Adv Photon Source, User Program Div, Argonne, IL 60439 USA. NR 13 TC 11 Z9 11 U1 1 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD SEP PY 2001 VL 8 BP 1140 EP 1148 DI 10.1107/S0909049501012006 PN 5 PG 9 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA 466MC UT WOS:000170648500004 ER PT J AU Zheng, J Beckman, SP Gray, JN Akinc, M AF Zheng, J Beckman, SP Gray, JN Akinc, M TI X-ray tomography study on green, state joining of silicon carbide using polymer precursors SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB X-ray tomography has been used to investigate the density variations in SiC joints formed using polymer pastes. It has been demonstrated that X-ray tomography provides accurate bulk density measurements and volumetric density gradients. The results suggest that the magnitude of the applied pressure after green state joining and the amount of polymer (polycarbosilane, PCS) in the joining pastes influence the green density of the joints. All joints are prepared and applied in air atmosphere and at room temperature. The green densities of the joints increase from 54% to 66% of theoretical with the increase of the applied pressure from ambient to 138 MPa. Highest joint density without applied pressure is achieved using paste containing 50 vol % PCS. Furthermore, allylhydridopopolycarbosilane- (AHPCS-) containing pastes resulted in higher densities at the joint-matrix interface, indicating infiltration of polymer into the matrix. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Ctr Nondestruct Evaluat, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Mech Engn, Ames, IA 50011 USA. RP Zheng, J (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 15 TC 5 Z9 5 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 2001 VL 84 IS 9 BP 1961 EP 1967 PG 7 WC Materials Science, Ceramics SC Materials Science GA 472BF UT WOS:000170962600007 ER PT J AU Sixta, ME Zhang, XF De Jonghe, LC AF Sixta, ME Zhang, XF De Jonghe, LC TI Flexural creep of an in situ-toughened silicon carbide SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID GRAIN-BOUNDARY PHASE; STRESS RUPTURE BEHAVIOR; HIGH-TEMPERATURE CREEP; SIC SINGLE-CRYSTALS; B-C ADDITIONS; SELF-DIFFUSION; CYCLIC FATIGUE; TENSILE CREEP; LIQUID-PHASE; NITRIDE AB Flexural creep behavior is reported for an in situ-toughened SiC between 1100 degrees and 1500 degreesC in four-point bending. The flexural creep rate of this SiC, sintered with aluminum, boron, and carbon (ABC-SiC), exhibits linear stress dependence, low apparent activation energy, and low incidence of cavitation and dislocation production. Most grain boundaries in this ceramic contain 1-5 mn intergranular films. The creep rate is consistent with a grain-boundary transport mechanism involving diffusion along the grain-boundary film-SiC interfaces. The microstructure and grain boundaries have been examined using transmission electron microscopy to assess possible changes during creep, particularly in relation to the applied stress direction. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Engn, Berkeley, CA 94720 USA. RP Intel Corp, Hillsboro, OR 97124 USA. NR 54 TC 14 Z9 14 U1 1 U2 6 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0002-7820 EI 1551-2916 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 2001 VL 84 IS 9 BP 2022 EP 2028 PG 7 WC Materials Science, Ceramics SC Materials Science GA 472BF UT WOS:000170962600016 ER PT J AU Kleveland, K Orlovskaya, N Grande, T Moe, AMM Einarsrud, MA Breder, K Gogotsi, G AF Kleveland, K Orlovskaya, N Grande, T Moe, AMM Einarsrud, MA Breder, K Gogotsi, G TI Ferroelastic behavior of LaCoO3-based ceramics SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID MECHANICAL-PROPERTIES; TEMPERATURE; MICROSTRUCTURE; LA1-XSRXCOO3 AB LaCoO3 and La0.8Ca0.2CoO3 ceramics show a nonelastic stress-strain behavior during four-point bending experiments where hysteresis loops are observed during loading-unloading cycles. Permanent strain is stored in the material after unloading, and a mechanism related to ferroelastic domain switching in the rhombohedral perovskite is proposed. Domain switching in the materials has been confirmed using X-ray diffractometry. Fracture toughnesses of La0.8Ca0.2CoO3 measured using single-edge notched beam and single-edge V-notched beam methods coincide and are equal to 2.2 MPa(.)m(1/2) at room temperature and decrease to similar to 1 MPa(.)m(1/2) at temperatures > 300 degreesC. A decrease in fracture toughness is consistent with ferroelastic behavior, because the rhombohedral distortion decreases with increasing temperature. C1 Norwegian Univ Sci & Technol, Dept Chem, N-7491 Trondheim, Norway. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Natl Acad Sci Ukraine, Inst Problems Strength, Kiev, Ukraine. RP Kleveland, K (reprint author), Norwegian Univ Sci & Technol, Dept Chem, N-7491 Trondheim, Norway. RI Einarsrud, Mari-Ann/I-5085-2014; Gogotsi, George/G-6331-2015; Grande, Tor/K-4125-2015 OI Gogotsi, George/0000-0003-1512-6020; NR 29 TC 48 Z9 48 U1 5 U2 22 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD SEP PY 2001 VL 84 IS 9 BP 2029 EP 2033 PG 5 WC Materials Science, Ceramics SC Materials Science GA 472BF UT WOS:000170962600017 ER PT J AU Nurmikko, AV Song, YK Zhou, HL Diagne, M Schneider, RP Takeuchi, T Han, J AF Nurmikko, AV Song, YK Zhou, HL Diagne, M Schneider, RP Takeuchi, T Han, J TI Vertical cavity blue light emitters SO JOURNAL OF THE KOREAN PHYSICAL SOCIETY LA English DT Article; Proceedings Paper CT International Conference on Superlattices Microstructures and Microdevices 2000 CY SEP 25-27, 2000 CL KYONGJU, SOUTH KOREA ID SURFACE-EMITTING LASER; WELL DIODE-LASERS; WAVELENGTHS; FILMS; GAIN; WAVE AB On going progress with blue and near ultraviolet vertical cavity light emitters, featuring III-nitride semiconductor active media, is described. Key issues include the design of high quality factor microresonators, understanding the microscopics of optical gain, and the implementation of carrier injection schemes, whose combined optimization is required for realizing a short wavelength diode surface emitting laser. C1 Brown Univ, Dept Phys, Providence, RI 02912 USA. Brown Univ, Div Engn, Providence, RI 02912 USA. Agilent Labs, Palo Alto, CA 94303 USA. Sandia Natl Labs, Albuquerque, NM 87111 USA. RP Nurmikko, AV (reprint author), Brown Univ, Dept Phys, Providence, RI 02912 USA. NR 16 TC 4 Z9 4 U1 0 U2 1 PU KOREAN PHYSICAL SOC PI SEOUL PA 635-4, YUKSAM-DONG, KANGNAM-KU, SEOUL 135-703, SOUTH KOREA SN 0374-4884 J9 J KOREAN PHYS SOC JI J. Korean Phys. Soc. PD SEP PY 2001 VL 39 IS 3 BP 558 EP 563 PG 6 WC Physics, Multidisciplinary SC Physics GA 473FK UT WOS:000171029700034 ER PT J AU Goldberg, KA Geary, K AF Goldberg, KA Geary, K TI Wave-front measurement errors from restricted concentric subdomains SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION LA English DT Article ID ZERNIKE POLYNOMIALS AB In interferometry and optical testing, system wave-front measurements that are analyzed on a restricted subdomain of the full pupil can include predictable systematic errors. In nearly all cases, the measured rms wave-front error and the magnitudes of the individual aberration polynomial coefficients underestimate the wave-front error magnitudes present in the full-pupil domain. We present an analytic method to determine the relationships between the coefficients of aberration polynomials defined on the full-pupil domain and those defined on a restricted concentric subdomain. In this way, systematic wave-front measurement errors introduced by subregion selection are investigated. Using vector and matrix representations for the wave-front aberration coefficients, we generalize the method to the study of arbitrary input wave fronts and subdomain sizes. While wave-front measurements on a restricted subdomain are insufficient for predicting the wave front of the full-pupil domain, studying the relationship between known full-pupil wave fronts and subdomain wave fronts allows us to set subdomain size limits for arbitrary measurement fidelity. (C) 2001 Optical Society of America. C1 Lawrence Berkeley Natl Lab, Ctr X Ray Opt, Berkeley, CA 94720 USA. RP Goldberg, KA (reprint author), Lawrence Berkeley Natl Lab, Ctr X Ray Opt, Berkeley, CA 94720 USA. NR 11 TC 16 Z9 17 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0740-3232 J9 J OPT SOC AM A JI J. Opt. Soc. Am. A-Opt. Image Sci. Vis. PD SEP PY 2001 VL 18 IS 9 BP 2146 EP 2152 DI 10.1364/JOSAA.18.002146 PG 7 WC Optics SC Optics GA 465YV UT WOS:000170618300013 PM 11551047 ER PT J AU Ohwada, K Hirota, K Rehrig, PW Gehring, PM Noheda, B Fujii, Y Park, SEE Shirane, G AF Ohwada, K Hirota, K Rehrig, PW Gehring, PM Noheda, B Fujii, Y Park, SEE Shirane, G TI Neutron diffraction study of the irreversible R-M-A-M-C phase transition in single crystal Pb[(Zn1/3Nb2/3)(1-x)Ti-x]O-3 SO JOURNAL OF THE PHYSICAL SOCIETY OF JAPAN LA English DT Article DE relaxor; ferroelectric; PZN-xPT; phase transition; electric field; neutron scattering ID X-RAY-DIFFRACTION; PIEZOELECTRIC PROPERTIES AB Single crystals of the relaxor PZN-xPT display an enormously strong piezoelectric character. Recent x-ray scattering studies have revealed novel electric-field induced phase transitions in PZN-8%PT. As-grown crystals exhibit a rhombohedral structure that, under application of an electric field oriented along [001]. transforms into a monoclinic (M-A) phase, and then irreversibly to another monoclinic (M-C) phase with increasing field strength. Since the latter phase change is very unusual, its transition sequence hats been investigated by using triple-axis neutron scattering techniques so that the "skin effect" observed by x-ray scattering can be avoided, and the entire crystal bulk is probed. Contour maps of the elastic scattering have been mapped out in each phase in the (H0L) zone with high q-resolution. Increasing the field strength within the Me phase induces a sharp c-axis jump around 15 kV/cm. This jump was observed easily with x-rays in previous studies, but it was not observed in 5 different crystals examined with neutrons. A subsequent high-energy x-ray study of the same crystals showed that the c-a-xis jump is distributed within the crystal volume, thereby washing out the jump. The observed R-M-A-M-C transformational path is in perfect accord with very recent first principles calculations by Bellaiche, Garcia, and Vanderbilt in the PZT system. C1 Univ Tokyo, ISSP, Neutron Scattering Lab, Tokai, Ibaraki 3191106, Japan. Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan. Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA. NIST, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11073 USA. Fraunhofer IBMT Technol Ctr Hialeah, Hialeah, FL 33010 USA. RP JAERI, Spring-8,1-1-1 Kouto Mikazuki Cho Sayo, Hyogo 6795148, Japan. RI Hirota, Kazuma/C-6797-2008; OI Gehring, Peter/0000-0002-9236-2046 NR 17 TC 56 Z9 56 U1 0 U2 19 PU PHYSICAL SOC JAPAN PI TOKYO PA YUSHIMA URBAN BUILDING 5F, 2-31-22 YUSHIMA, BUNKYO-KU, TOKYO, 113-0034, JAPAN SN 0031-9015 J9 J PHYS SOC JPN JI J. Phys. Soc. Jpn. PD SEP PY 2001 VL 70 IS 9 BP 2778 EP 2783 DI 10.1143/JPSJ.70.2778 PG 6 WC Physics, Multidisciplinary SC Physics GA 476FZ UT WOS:000171216700042 ER PT J AU Zhang, T Song, JH Tian, XB Chu, PK Brown, IG AF Zhang, T Song, JH Tian, XB Chu, PK Brown, IG TI Dynamic mixing deposition of niobium nitride films by cathodic are plasma in ambient nitrogen SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A LA English DT Article ID THIN-FILMS; JUNCTIONS AB Two cathodic are plasma deposition processes have been used to deposit niobium nitride films in ambient nitrogen: (a) cathodic are plasma deposition without dynamic mixing and (b) cathodic arc plasma deposition with, energetic ion dynamic mixing. Smooth and continuous niobium nitride films were fabricated at low temperature in process (b) but at higher temperature (500 degreesC) in process (a). The effects of the substrate temperature on the film composition and preferred orientation were investigated. In process (a), films deposited at room temperature and 300 degreesC exhibited a preferred orientation of (220) whereas those deposited at 500 degreesC showed a preferred orientation of (200). The nitrogen content in the film synthesized in process (b) is higher than that in the films deposited in process (a). Our results show that with energetic ion dynamic mixing, niobium nitride films with excellent properties can be fabricated at low substrate temperature using a niobium metal arc plasma source in a nitrogen plasma immersion configuration. (C) 2001 American Vacuum Society. C1 City Univ Hong Kong, Dept Phys & Mat Sci, Kowloon, Hong Kong, Peoples R China. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. Beijing Normal Univ, Inst Low Energy Nucl Phys, Ctr Radiat, Beijing 100875, Peoples R China. RP City Univ Hong Kong, Dept Phys & Mat Sci, 83 Tat Chee Ave, Kowloon, Hong Kong, Peoples R China. EM paul.chu@cityu.edu.hk RI Chu, Paul/B-5923-2013 OI Chu, Paul/0000-0002-5581-4883 NR 15 TC 10 Z9 12 U1 0 U2 3 PU A V S AMER INST PHYSICS PI MELVILLE PA STE 1 NO 1, 2 HUNTINGTON QUADRANGLE, MELVILLE, NY 11747-4502 USA SN 0734-2101 EI 1520-8559 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A PD SEP-OCT PY 2001 VL 19 IS 5 BP 2048 EP 2050 DI 10.1116/1.1372896 PG 3 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 478YP UT WOS:000171376700003 ER PT J AU Hanson, AL Thieberger, P Steske, DB Zajic, V Zhang, SY Ludewig, H AF Hanson, AL Thieberger, P Steske, DB Zajic, V Zhang, SY Ludewig, H TI Electron emission from ion bombarded stainless-steel surfaces coated and noncoated with TiN and its relevance to the design of high intensity storage rings SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID INSTABILITY AB High intensity proton synchrotrons and proton storage rings are being designed with TiN coated vacuum components to reduce electron cloud buildup, which can lead to multipacting and instabilities. It has been established that when the surfaces are irradiated with energetic electrons, the TiN coatings reduce the electron cloud buildup because the TiN has a higher work function when compared to metallic surfaces. The present work investigates the electron emission from these coatings when the surface is bombarded with 28 MeV protons, 126 MeV oxygen ions, and 182 MeV gold ions. Understanding the electron emission from ion bombardment is important for the machine collimator regions, where the beam halo is removed. (C) 2001 American Vacuum Society. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Hanson, AL (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 22 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 2001 VL 19 IS 5 BP 2116 EP 2121 DI 10.1116/1.1374616 PG 6 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 478YP UT WOS:000171376700014 ER PT J AU Ho, P Johannes, JE Buss, RJ Meeks, E AF Ho, P Johannes, JE Buss, RJ Meeks, E TI Modeling the plasma chemistry of C2F6 and CHF3 etching of silicon dioxide, with comparisons to etch rate and diagnostic data SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID ELECTRON-IMPACT-IONIZATION; INDUCTIVELY-COUPLED PLASMA; LASER-INDUCED FLUORESCENCE; CYCLOTRON-RESONANCE PLASMA; HIGH-DENSITY PLASMAS; ABSOLUTE CROSS-SECTIONS; FLUOROCARBON GASES CF4; ABSORPTION-SPECTROSCOPY; RADICAL DENSITIES; REFERENCE CELL AB A detailed chemical reaction mechanism is reported that describes the CA and CHF3 plasma etching of silicon dioxide, which is widely used in the fabrication of microelectronic devices. The gas-phase part of the C2F6 mechanism involves 28 species and 132 reactions, while the surface part involves 2 materials, 6 species, and 85 reactions. Rate parameters are generally taken from independent studies in the literature, or estimated from rates measured for related species. Zero-dimensional simulations using these mechanisms compare well with a large body of etch rate and diagnostic measurements in three different high-density plasma reactors. The diagnostic measurements include electron and negative ion absolute densities, CF, CF2, and SiF densities, gas temperatures, and ion current densities. An analysis of the dominant reaction paths shows the importance of gas-phase electron impact reactions and the need to include reactions of the etch-product species. On the surface, the etching reactions are dominated by ion-assisted processes; spontaneous etching by F atoms is relatively unimportant. (C) 2001 American Vacuum Society. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. React Design, San Diego, CA 92121 USA. RP Ho, P (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 89 TC 73 Z9 74 U1 2 U2 11 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 2001 VL 19 IS 5 BP 2344 EP 2367 DI 10.1116/1.1387048 PG 24 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 478YP UT WOS:000171376700048 ER PT J AU Lim, SH Washburn, J Liliental-Weber, Z Shindo, D AF Lim, SH Washburn, J Liliental-Weber, Z Shindo, D TI Transmission electron microscopy of threading dislocations in ZnO films grown on sapphire SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID MOLECULAR-BEAM EPITAXY; GAN FILMS; THIN-FILMS; DEFECTS; HETEROSTRUCTURES AB Threading dislocations in wurtzite ZnO films grown on the (11 (2) over bar0) a plane of sapphire were studied by transmission electron microscopy. A majority of the threading dislocations were found to be of screw or mixed character. Dislocation half loops, elongated along the c axis, were observed. It is likely that they are formed when two screw dislocations of opposite sign attract each other during growth and combine. (C) 2001 American Vacuum Society. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Tohoku Univ, Inst Multidisciplinary Res Adv Mat, Sendai, Miyagi 9808577, Japan. RP Lim, SH (reprint author), Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA. RI Liliental-Weber, Zuzanna/H-8006-2012; Shindo, Daisuke/I-3865-2012 NR 21 TC 28 Z9 30 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 2001 VL 19 IS 5 BP 2601 EP 2603 DI 10.1116/1.1397462 PG 3 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 478YP UT WOS:000171376700085 ER PT J AU Liu, C Macrander, A AF Liu, C Macrander, A TI Simple vacuum heater and its application for annealing TiO2 films SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article ID THIN-FILMS AB A simple lamp heater design and use of permanent magnets to mount the heater to a commercial sputter deposition system are reported. The heater was applied to anneal a TiO2 thin film sample up to 350 degreesC. The annealing effect was evaluated using spectroscopic ellipsometry. The results were compared with that of another TiO2 sample grown under identical conditions but without aftergrowth annealing. The TiO2 samples were made by using reactive sputtering on a pure Ti target. (C) 2001 American Vacuum Society. C1 Argonne Natl Lab, User Program Div, Argonne, IL 60439 USA. RP Liu, C (reprint author), Argonne Natl Lab, User Program Div, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 6 TC 2 Z9 3 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 2001 VL 19 IS 5 BP 2703 EP 2705 DI 10.1116/1.1372898 PG 3 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 478YP UT WOS:000171376700102 ER PT J AU Langley, RA Browning, JF Balsley, SD Banks, JC Doyle, BL Wampler, WR Beavis, LG AF Langley, RA Browning, JF Balsley, SD Banks, JC Doyle, BL Wampler, WR Beavis, LG TI Technique for production of calibrated metal hydride films SO JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A-VACUUM SURFACES AND FILMS LA English DT Article C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Langley, RA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. OI Browning, James/0000-0001-8379-259X NR 2 TC 3 Z9 3 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 0734-2101 J9 J VAC SCI TECHNOL A JI J. Vac. Sci. Technol. A-Vac. Surf. Films PD SEP-OCT PY 2001 VL 19 IS 5 BP 2706 EP 2708 DI 10.1116/1.1376710 PG 3 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA 478YP UT WOS:000171376700103 ER PT J AU Tomasko, D Williams, GP Butler, JP AF Tomasko, D Williams, GP Butler, JP TI Engineering approach for tier 2 RBCA evaluations at NAPL-contaminated sites SO JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT-ASCE LA English DT Article ID GROUNDWATER SYSTEMS; ORGANIC-CHEMICALS; INFILTRATION; MIGRATION; WATER; SOIL AB Groundwater contaminated with non-aqueous-phase liquids (NAPLs) poses human health risks and evaluation of these risks requires estimated groundwater NAPL concentrations. Site NAPL concentrations are typically evaluated using the U.S. Environmental Protection Agency's tiered risk-based corrective action (RBCA) system. Tier 1 uses conservative assumptions and little site-specific data, while tier 2 requires more detailed site-specific data. This paper presents an engineering approach that can be used to predict maximum groundwater NAPL concentrations resulting from NAPL spills. This screening tool was developed by deriving an analytical solution for a partial differential equation describing NAPL transport through the unsaturated zone. Model processes include dissolution, advection, dispersion, sorption, volatilization, and first-order degradation. Results are obtained using two nondimensional parameters and engineering plots for a wide range of conditions. A brief study is provided to demonstrate the application of the model. Because the engineering plots are easy to use and facilitate sensitivity analyses, the model is recommended for screening and RBCA tier 2 analyses. C1 Argonne Natl Lab, Res Sci Environm Assessment Div, Argonne, IL 60439 USA. RP Tomasko, D (reprint author), Argonne Natl Lab, Res Sci Environm Assessment Div, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Williams, Gustavious/P-7252-2014 OI Williams, Gustavious/0000-0002-2781-0738 NR 29 TC 0 Z9 0 U1 0 U2 1 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 0733-9496 J9 J WATER RES PL-ASCE JI J. Water Resour. Plan. Manage.-ASCE PD SEP-OCT PY 2001 VL 127 IS 5 BP 324 EP 332 DI 10.1061/(ASCE)0733-9496(2001)127:5(324) PG 9 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA 465ZW UT WOS:000170620700006 ER PT J AU Kazianis, S Gimenez-Conti, I Setlow, RB Woodhead, AD Harshbarger, JC Trono, D Ledesma, M Nairn, RS Walter, RB AF Kazianis, S Gimenez-Conti, I Setlow, RB Woodhead, AD Harshbarger, JC Trono, D Ledesma, M Nairn, RS Walter, RB TI MNU induction of neoplasia in a platyfish model SO LABORATORY INVESTIGATION LA English DT Article ID METHYL-N-NITROSOUREA; LINKAGE GROUP-V; MELANOMA FORMATION; CDKN2 GENE; CELL-DIFFERENTIATION; MALIGNANT-MELANOMA; TUMOR-SUPPRESSOR; X-RAYS; XIPHOPHORUS; SUSCEPTIBILITY AB Interspecific hybrid crosses between members of the fish genus Xiphophorus have been used for over 70 years to study the genetic aspects of melanoma formation. In the well-established "Gordon-Kosswig" cross, the platyfish X. maculatus is outcrossed to the swordtail X. helleri, and the resulting backcross segregants spontaneously develop melanoma. We recently produced a distinct cross between X. maculatus and another platyfish species, X couchianus. X. maculatus strain Jp 163 A is homozygous for several X-linked pigment pattern genes, including the Spotted dorsal (Sd), Dorsal red (Dr), and Anal fin spot (A. Af is a sex-limited trait, coding exclusively for melanophores distributed on the modified anal fin or "gonopodium" in the adult male fish. Within F-1 and BC1 hybrids (to X couchianus), the Sd pigment pattern is phenotypically suppressed, whereas Dr and Af are enhanced. We exposed BC1 hybrids to the direct-acting carcinogen N-methyl-N-nitrosourea (MNU). Treatment led to the development of schwannomas, fibrosarcomas, and retinoblastomas. In addition, numerous MNU-treated males that inherited Af developed a pronounced melanotic phenotype, with melanin-containing cells oftentimes totally covering the gonopodium and extending further to grow within the ventral regions of the fish. Genetic linkage analysis of the BC, hybrids revealed a significant (p < 0.01) association between CDKN2X genotype and the phenotypic degree of melanization. Such an association is consistent with a locus within linkage group V playing a role in the development of melanosis and delineates three genetic preconditions and a carcinogenic scheme resulting in melanosis of the ventral regions of hybrid fish. The overall study further alludes to the potential of using Xiphophorus fish to study carcinogenic mechanisms for tumors other than melanoma (schwannoma, fibrosarcoma, and retinoblastoma) and should enable extensive pathologic and molecular genetic studies of derived neoplastic abnormalities. C1 SW Texas State Univ, Dept Chem & Biochem, San Marcos, TX 78666 USA. Univ Texas, MD Anderson Canc Ctr, Div Sci Pk Res, Dept Carcinogenesis, Smithville, TX USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. George Washington Univ, Med Ctr, Dept Pathol, Washington, DC 20037 USA. RP Walter, RB (reprint author), SW Texas State Univ, Dept Chem & Biochem, 601 Univ Dr, San Marcos, TX 78666 USA. FU NCI NIH HHS [CA76693, CA09480, CA55245, CA75137]; NCRR NIH HHS [RR12253]; NIEHS NIH HHS [ES07784] NR 35 TC 20 Z9 20 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0023-6837 J9 LAB INVEST JI Lab. Invest. PD SEP PY 2001 VL 81 IS 9 BP 1191 EP 1198 DI 10.1038/labinvest.3780333 PG 8 WC Medicine, Research & Experimental; Pathology SC Research & Experimental Medicine; Pathology GA 473AF UT WOS:000171016600003 PM 11555667 ER PT J AU Spielman, RB AF Spielman, RB TI Guest editor's preface: Z-pinch special issue SO LASER AND PARTICLE BEAMS LA English DT Editorial Material C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Spielman, RB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4221 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PD SEP PY 2001 VL 19 IS 3 BP 321 EP 321 DI 10.1017/S0263034601193158 PG 1 WC Physics, Applied SC Physics GA 504FD UT WOS:000172845900001 ER PT J AU Reisman, DB Hammer, JH Toor, A De Groot, JS AF Reisman, DB Hammer, JH Toor, A De Groot, JS TI Characteristics of plasma merging in wire arrays on Z SO LASER AND PARTICLE BEAMS LA English DT Article ID X-RAY POWER; Z-PINCHES; NUMBER; ENHANCEMENT; SIMULATIONS; IMPLOSION AB A computational study of tungsten wire array z pinches on the Z facility at Sandia National Laboratories shows that individual wires form a core-corona structure early in the current pulse. Further analysis indicates that at 1 mm or smaller interwire gap, the expanding and later merging wire plasmas prevent the growth of m = 0 sausage modes. Although a completely uniform shell is not observed in the simulations, the Hussey-Roderick profile-a characteristic of uniform shell implosions-is seen. Differences in shell characteristics between small- and large-diameter wires are observed, possibly explaining performance differences between these two arrangements. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Calif Davis, Davis, CA 94515 USA. RP Reisman, DB (reprint author), Lawrence Livermore Natl Lab, L-041,POB 808, Livermore, CA 94550 USA. NR 12 TC 4 Z9 4 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4221 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PD SEP PY 2001 VL 19 IS 3 BP 403 EP 408 DI 10.1017/S0263034601193146 PG 6 WC Physics, Applied SC Physics GA 504FD UT WOS:000172845900008 ER PT J AU Volkov, NB Golub, TA Spielman, RB Gondarenko, NA AF Volkov, NB Golub, TA Spielman, RB Gondarenko, NA TI Dynamics and stability of twisted-wire arrays SO LASER AND PARTICLE BEAMS LA English DT Article ID Z-PINCH IMPLOSIONS; X-RAY-RADIATION; TURBULENCE; PLASMA; MODEL; LOADS AB A multiwire screw pinch, a variant of a z-pinch load, is proposed as a means for further improvement of load performance for high-current 100-ns pulsed-power generators used for terawatt X-ray radiation. Wires twisted along a curved load surface are suggested to be an effective way to create an axial magnetic field and to generate and to maintain rotation of the subsequently formed plasma shell due to conservation of angular momentum. A multiwire screw pinch is predicted to mitigate the growth of the magneto-Rayleigh-Taylor instabilities, to provide a higher pinch compression ratio and more effective X-ray generation compared to classical z-pinch loads. A model based on the self-consistent simulation of the dynamics of a twisted plasma shell and the development of Rayleigh-Taylor (R-T) perturbations on a plasma surface is proposed to quantitatively study the effect of various physical factors on the generation of X rays. The model provides us with a tool for the analysis of processes that occur during the implosion of the plasma-shell-wire-core system. We plan for the R-T perturbations to break through the plasma shell at the moment when the internal radius of a shell becomes zero, where the greatest possible values of kinetic energy and X-ray radiation power ought to be obtained. The results of numerical simulations for the Sandia National Laboratories' Z generator are presented and discussed. C1 Russian Acad Sci, Ural Div, Inst Electrophys, Ekaterinburg 620016, Russia. GNG Enterprises Inc, Springfield, VA 22152 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Maryland, Inst Plasma Res, College Pk, MD 20742 USA. RP Volkov, NB (reprint author), Russian Acad Sci, Ural Div, Inst Electrophys, Amundsen St 106, Ekaterinburg 620016, Russia. EM nbv@ami.uran.ru NR 38 TC 2 Z9 2 U1 0 U2 0 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PD SEP PY 2001 VL 19 IS 3 BP 451 EP 463 DI 10.1017/S0263034601193134 PG 13 WC Physics, Applied SC Physics GA 504FD UT WOS:000172845900011 ER PT J AU Cuneo, ME Vesey, RA Hammer, JH Porter, JL Ruggles, LE Simpson, WW AF Cuneo, ME Vesey, RA Hammer, JH Porter, JL Ruggles, LE Simpson, WW TI Zero-dimensional energetics scaling models for z-pinch-driven hohlraums SO LASER AND PARTICLE BEAMS LA English DT Article ID INERTIAL-CONFINEMENT-FUSION; X-RAY SOURCES; 2-DIMENSIONAL SIMULATIONS; DENSE-PLASMA; POWER; PHYSICS; GAIN AB Wire array z pinches on the Z accelerator provide the most intense laboratory source of soft X rays in the world. The unique combination of a near-Planckian radiation source with high X-ray production efficiency (10 to 15% wall plug), large X-ray powers and energies (> 100 TW, greater than or equal to0.8 MJ in 6 ns to 7 ns), large characteristic hohlraum volumes (0.5 to > 10 cm(3)), long pulse lengths (5 to 20 ns), and low capital cost (<$50-$100/radiated Joule) may make z pinches a good match to the requirements for driving high-yield scale (>200 MJ yield) ICF capsules with adequate radiation symmetry and margin. The z-pinch-driven hohlraum approach of Hammer et gal. (1999) may provide a conservative and robust solution to the requirements for high yield, and is currently being studied on the Z accelerator. This paper describes a multiple-region, 0-D hohlraum energetics model for z-pinch-driven hohlraums in four configurations. We observe consistency between the model and the measured X-ray powers and hohlraum wall temperatures to within +/-20% in X-ray flux, for the four configurations. The scaling of pinch energy and radiation-driven anode-cathode gap closure with drive current are also examined. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Cuneo, ME (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 40 TC 27 Z9 27 U1 0 U2 3 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4221 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PD SEP PY 2001 VL 19 IS 3 BP 481 EP 495 DI 10.1017/S0263034601193055 PG 15 WC Physics, Applied SC Physics GA 504FD UT WOS:000172845900013 ER PT J AU Deeney, C Coverdale, CA Douglas, MR AF Deeney, C Coverdale, CA Douglas, MR TI A review of long-implosion-time z pinches as efficient and high-power radiation sources SO LASER AND PARTICLE BEAMS LA English DT Article ID RAYLEIGH-TAYLOR INSTABILITY; WIRE-ARRAY IMPLOSIONS; PLASMA OPENING SWITCH; GAS PUFF IMPLOSION; X-RAY-EMISSION; HEURISTIC MODEL; ENERGY; NUMBER; PERFORMANCE; ENHANCEMENT AB In the past few years, long-implosion-time (150 ns to 200 ns) z pinches have made significant progress in terms of their ability to make kilovolt X rays or to produce high-power subkilovolt emissions. These advances are enabling the community to utilize lower-cost pulsed power designs for high current X-ray facilities. The advances will be reviewed in historical context in this paper, plus some new physics regimes and understanding resulting from this work will be highlighted. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Deeney, C (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 61 TC 16 Z9 17 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH ST, NEW YORK, NY 10011-4221 USA SN 0263-0346 J9 LASER PART BEAMS JI Laser Part. Beams PD SEP PY 2001 VL 19 IS 3 BP 497 EP 506 DI 10.1017/S0263034601193079 PG 10 WC Physics, Applied SC Physics GA 504FD UT WOS:000172845900014 ER PT J AU Rau, GH Ralston, S Southon, JR Chavez, FP AF Rau, GH Ralston, S Southon, JR Chavez, FP TI Upwelling and the condition and diet of juvenile rockfish: A study using (14)C, (13)C, and (15)N natural abundances SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID SHORTBELLY ROCKFISH; CENTRAL CALIFORNIA; MONTEREY BAY; RADIOCARBON; C-13/C-12; SEBASTES; FISH; ORGANISMS; N-15/N-14 AB Juvenile Sebastes jordani individuals sampled in late spring 1995, 1996, and 1997 near Monterey Bay, California, were analyzed for Delta (14)C, delta (13)C, and delta (15)N. As anticipated, a strong negative correlation was found between mean annual juvenile rockfish Delta (14)C and the preceding 3-month average Bakun upwelling index for this region. The sensitivity of this isotopic response by juvenile rockfish to upwelling variations was similar to that previously observed in surface-water inorganic carbon in nearby Half Moon Bay (Robinson 1981). This indicates that the Delta (14)C of surface-dwelling marine fish can be used as a measure of fish feeding in freshly upwelled (14)C-depleted water. However, we found no correlation between this parameter and fish somatic condition as measured by deviations in the regressions of individual fish (1) weight on length, (2) otolith size on fish length, or (3) total lipid content on dry weight. This questions the role upwelling plays in affecting juvenile rockfish condition. Also unrelated to fish condition were fish delta (13)C and delta (15)N, implying that the condition of juvenile S. jordani is unaffected by variation in the consumption of specific, isotopically discernible food resources. C1 Univ Calif Santa Cruz, Inst Marine Sci, Santa Cruz, CA 95064 USA. Natl Marine Fisheries Serv, Santa Cruz, CA 95060 USA. Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. Monterey Bay Aquarium Res Inst, Moss Landing, CA 95039 USA. RP Rau, GH (reprint author), Univ Calif Santa Cruz, Inst Marine Sci, Santa Cruz, CA 95064 USA. EM rau4@llnl.gov NR 28 TC 10 Z9 11 U1 1 U2 10 PU AMER SOC LIMNOLOGY OCEANOGRAPHY PI WACO PA 5400 BOSQUE BLVD, STE 680, WACO, TX 76710-4446 USA SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD SEP PY 2001 VL 46 IS 6 BP 1565 EP 1570 PG 6 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA 466PA UT WOS:000170652900029 ER PT J AU Castiglione, F Celebre, G De Luca, G Longeri, M AF Castiglione, F Celebre, G De Luca, G Longeri, M TI The use of heteronuclear multiple quantum spectra in the automatic analysis of NMR spectra of samples dissolved in liquid crystalline phases SO LIQUID CRYSTALS LA English DT Article ID BAND DECOUPLING SEQUENCE; HIGH-RESOLUTION NMR; MOLECULAR-STRUCTURE; ORDER PARAMETERS; SOLIDS; SELECTION; SOLVENTS; WALTZ-16; NUCLEI; AID AB For spin systems with N-1 and N-S interacting nuclei of magnetogyric ratio gamma (l) and gamma (S) respectively, it is possible to obtain multiple quantum spectra characterized by changes in the magnetic numbers m(X) by N-I, (N-I-1)..., 0 with X = I, S. The use of such heteronuclear MQ spectra as an aid in the automatic analysis of NMR spectra of both rigid and flexible molecules dissolved in liquid crystalline phases, is discussed. It has been found that when I = H-1 and S = F-19, the decoupling efficiency of the standard multipulse sequences, developed and optimized for heteronuclear decoupling in isotropic liquids, depends on the spin system and also on the overall orientation of the molecule when orienting mesophases are involved. These facts impose limitations on the applicability of a procedure which, when the decoupled heteronuclear MQ spectrum is obtained, significantly reduces the computing requirements of the automated spectral analysis. C1 Univ Calabria, Dipartimento Chim, I-87036 Arcavacata Di Rende, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Longeri, M (reprint author), Univ Calabria, Dipartimento Chim, I-87036 Arcavacata Di Rende, Italy. OI De Luca, Giuseppina/0000-0002-7509-2232; Celebre, Giorgio/0000-0002-8569-6726 NR 32 TC 2 Z9 2 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA 11 NEW FETTER LANE, LONDON EC4P 4EE, ENGLAND SN 0267-8292 J9 LIQ CRYST JI Liq. Cryst. PD SEP PY 2001 VL 28 IS 9 BP 1403 EP 1413 PG 11 WC Chemistry, Multidisciplinary; Crystallography; Materials Science, Multidisciplinary SC Chemistry; Crystallography; Materials Science GA 469DG UT WOS:000170798000015 ER PT J AU Gor'kov, LP Kresin, VZ AF Gor'kov, LP Kresin, VZ TI Giant magnetooscillations of the Josephson current SO LOW TEMPERATURE PHYSICS LA English DT Article ID MANGANITES; TRANSITION; STATE AB Josephson current flowing through an antiferromagnetic metallic barrier is studied. We consider the most interesting case of the spin-valve structure when the barrier is formed by ferromagnetic layers ordered antiferromagnetically in the direction perpendicular to the current. The most remarkable feature is the onset of giant magnetooscillations of the current amplitude. (C) 2001 American Institute of Physics. C1 Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. LD Landau Theoret Phys Inst, Moscow, Russia. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Gor'kov, LP (reprint author), Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32306 USA. NR 14 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 1063-777X J9 LOW TEMP PHYS+ JI Low Temp. Phys. PD SEP-OCT PY 2001 VL 27 IS 9-10 BP 709 EP 712 DI 10.1063/1.1401179 PG 4 WC Physics, Applied SC Physics GA 488QM UT WOS:000171947200006 ER PT J AU McClelland, JF Jones, RW AF McClelland, JF Jones, RW TI FTIR photoacoustic spectroscopy of diesel lubricant oils containing particulate matter((c)) SO LUBRICATION ENGINEERING LA English DT Article DE lubricant analytical techniques; infrared spectroscopy; particulates; internal combustion engine oils; condition monitoring; soot; FTIR; photoacoustic spectroscopy ID EXHAUST-GAS RECIRCULATION; DEGRADATION; EMISSIONS; QUALITY AB Monitoring of engine lubricants in service is important for evaluating engine conditions as well as the performance of new and existing lubricant formulations. Fourier-transform infrared (FTIR) spectroscopy has previously been demonstrated as an effective technique for analyzing lubricant condition, but used oils laden with soot and other particulate matter are difficult to analyze with common FTIR sampling techniques because of the strong light absorption and scattering by the particulates. FTIR photoacoustic spectroscopy is examined here as an alternative sampling technique for analyzing particulate-laden oils. Diesel-engine oils spiked with carbon black and phorone are analyzed quantitatively for particulate and carbonyl-species content using FTIR photoacoustic spectroscopy. Photoacoustics is found to be insensitive to the light scattering by particulate matter, but the strength of spectrum bands is reduced by the light absorption by particulate matter. A method is proposed to compensate for the loss of band strength so that quantitative measurements can be made. C1 MTEC Photoacoust Inc, Ames, IA 50014 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP McClelland, JF (reprint author), MTEC Photoacoust Inc, Ames, IA 50014 USA. NR 13 TC 2 Z9 2 U1 1 U2 1 PU SOC TRIBOLOGISTS & LUBRICATION ENGINEERS PI PARK RIDGE PA 840 BUSSE HIGHWAY, PARK RIDGE, IL 60068 USA SN 0024-7154 J9 LUBR ENG JI Lubric. Eng. PD SEP PY 2001 VL 57 IS 9 BP 17 EP 21 PG 5 WC Engineering, Mechanical SC Engineering GA 467VH UT WOS:000170724100004 ER PT J AU Frankfurt, VI Kupperman, DS AF Frankfurt, VI Kupperman, DS TI Review of electromagnetic NDT methods for monitoring the degradation of nuclear reactor components SO MATERIALS EVALUATION LA English DT Article DE electromagnetic techniques; barkhausen effect; magnetic hysteresis; higher harmonics; nondestructive testing; reactor pressure vessel steels; degradation ID PRESSURE-VESSEL STEELS; NONDESTRUCTIVE MEASUREMENT; NEUTRON-IRRADIATION AB This paper presents a summary of electromagnetic techniques used for nondestructive testing (NDT) of degradation of nuclear reactor components. Magnetic methods that use direct or low frequency magnetic fields offer a major advantage for field applications. In particular, the use of higher harmonics may provide a valuable NDT method for reactor pressure vessel steels. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Kupperman, DS (reprint author), Amer NTN Bearing Manufacture Corp, 1500 Holmes Rd, Elgin, IL 60123 USA. EM dsk@anl.gov NR 33 TC 4 Z9 4 U1 1 U2 3 PU AMER SOC NONDESTRUCTIVE TEST PI COLUMBUS PA 1711 ARLINGATE LANE PO BOX 28518, COLUMBUS, OH 43228-0518 USA SN 0025-5327 J9 MATER EVAL JI Mater. Eval. PD SEP PY 2001 VL 59 IS 9 BP 1053 EP 1057 PG 5 WC Materials Science, Characterization & Testing SC Materials Science GA 468GW UT WOS:000170750600002 ER PT J AU Smimov, BI Burenkov, YA Goretta, KC Ma, B Balachandran, U AF Smimov, BI Burenkov, YA Goretta, KC Ma, B Balachandran, U TI Thermoelastic response of polycrystalline SrFe1.2Co0.3Ox SO MATERIALS LETTERS LA English DT Article DE mixed-conducting oxide; Sr-Fe-Co-O; thermal expansion; elastic modulus ID TRANSPORT-PROPERTIES; NEUTRON-DIFFRACTION; ELASTIC-CONSTANTS; SUPERCONDUCTORS; CONDUCTION; METHANE; SYNGAS; (BI AB We obtained the thermal expansion coefficients and elastic modulus data for approximate to 95%-dense polycrystalline SrFe1.2Co0.3Ox bars. The thermal expansion coefficient was 13.4 x 10(6) degreesC(-1) at 25 degreesC and increased monotonically to 14.5 x 10(-6) degreesC(-1) at 1000 degreesC. The elastic modulus was 82.6 GPa at 25 degreesC and 71.5 GPa at 900 degreesC. These data are compared with those for other high-temperature materials. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Russian Acad Sci, AF Ioffe Physicotech Inst, St Petersburg 194021, Russia. RP Goretta, KC (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Ma, Beihai/I-1674-2013 OI Ma, Beihai/0000-0003-3557-2773 NR 24 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-577X J9 MATER LETT JI Mater. Lett. PD SEP PY 2001 VL 50 IS 4 BP 259 EP 262 DI 10.1016/S0167-577X(01)00236-1 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 473ZU UT WOS:000171080400014 ER PT J AU Kirby, KW Jankiewicz, A Kupp, D Walls, C Janney, M AF Kirby, KW Jankiewicz, A Kupp, D Walls, C Janney, M TI Gelcasting of ceramic radomes in the Si3N4-Al2O3-AlN-SiO2 system SO MATERIALS TECHNOLOGY LA English DT Review C1 HRL Labs LLC, Malibu, CA USA. Raytheon Missile Syst, Tucson, AZ USA. Fraunhofer USA, Newark, DE USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. RP HRL Labs LLC, Malibu, CA USA. EM mailkwkirby@hrl.com NR 6 TC 8 Z9 8 U1 1 U2 8 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 1066-7857 EI 1753-5557 J9 MATER TECHNOL JI Mater. Technol. PD SEP PY 2001 VL 16 IS 3 BP 187 EP 190 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA 499QB UT WOS:000172580900010 ER PT J AU Zhong, Z Dilmanian, FA Bacarian, T Zhong, N Chapman, D Ren, B Wu, XY Weinman, HJ AF Zhong, Z Dilmanian, FA Bacarian, T Zhong, N Chapman, D Ren, B Wu, XY Weinman, HJ TI Producing parallel x rays with a bent-crystal monochromator and an x-ray tube SO MEDICAL PHYSICS LA English DT Article DE monochromatic x ray; parallel beam; monochromator; computed tomography ID SYNCHROTRON-RADIATION; CORONARY ANGIOGRAPHY; LAUE MONOCHROMATOR; MAMMOGRAPHY; RADIOGRAPHY; PHANTOM; ENERGY; BEAM AB A bent Laue monochromator and a conventional x-ray tube were used to produce a fan beam that was parallel in the plane perpendicular to the plane of the fan. The x-ray fan beam was tunable in energy and had about 12% energy bandwidth at a slice height of 5 mm when tuned to 50 keV. The beam's energy was slightly coupled to the vertical position on the beam's height. The slice height could be varied from I to 10 mm. The flux at 50 keV was approximately 2 X 10(6) photons/mm(2)/s with a rotating anode tungsten x-ray tube operating at 120 kVp and 100 mA. The narrow energy bandwidth of the beam produced is advantageous over a conventional divergent polychromatic beam for all radiography applications, while the parallelism of the beam enhances its intensity by about threefold and offers some advantages for computed tomography. (C) 2001 American Association of Physicists in Medicine. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. IIT, CSRRI, Chicago, IL 60616 USA. Schering AG, D-13342 Berlin, Germany. RP Zhong, Z (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RI Ren, Bin/G-4641-2010 OI Ren, Bin/0000-0002-9821-5864 NR 19 TC 6 Z9 7 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 0094-2405 J9 MED PHYS JI Med. Phys. PD SEP PY 2001 VL 28 IS 9 BP 1931 EP 1936 DI 10.1118/1.1395024 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 475QJ UT WOS:000171175300011 PM 11585224 ER PT J AU Michalet, X Lacoste, TD Weiss, S AF Michalet, X Lacoste, TD Weiss, S TI Ultrahigh-resolution colocalization of spectrally separable point-like fluorescent probes SO METHODS LA English DT Article DE superresolution; diffraction limit; fluorescence; microscopy; confocal; two-photon; single molecule; TransFluoSphere; semiconductor nanocrystal; quantum dot ID SCANNING OPTICAL MICROSCOPY; 2-PHOTON EXCITATION; QUANTUM DOTS; NANOCRYSTALS; DIFFRACTION; SUPERRESOLUTION; SPECTROSCOPY; IMAGES; LIGHT; DECONVOLUTION AB An ultrahigh-resolution colocalization method based on the simultaneous acquisition and analysis of spectrally separated images of the excitation point-spread function of point-like fluorescent probes Is reviewed. It is shown that molecular distances can be measured with accuracy better than 10 nm using conventional far-field optics. A detailed account of the methodology, theoretical considerations, signal processing, and data fitting algorithms is given. (C) 2001 Academic Press. C1 Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. RP Weiss, S (reprint author), Lawrence Berkeley Lab, Div Mat Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI weiss, shimon/B-4164-2009; Michalet, Xavier/A-9704-2009 OI weiss, shimon/0000-0002-0720-5426; Michalet, Xavier/0000-0001-6602-7693 FU NCRR NIH HHS [1 R01 RR1489101, R01 RR014891] NR 66 TC 48 Z9 50 U1 0 U2 7 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 1046-2023 J9 METHODS JI Methods PD SEP PY 2001 VL 25 IS 1 BP 87 EP 102 DI 10.1006/meth.2001.1218 PG 16 WC Biochemical Research Methods; Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 472YR UT WOS:000171013000009 PM 11559000 ER PT J AU Bedson, TR Palmer, RE Wilcoxon, JP AF Bedson, TR Palmer, RE Wilcoxon, JP TI Electron beam lithography in passivated gold nanoclusters SO MICROELECTRONIC ENGINEERING LA English DT Article; Proceedings Paper CT 26th International Conference on Micro- and Nano-Engineering CY SEP 18-21, 2000 CL JENA, GERMANY DE electron beam lithography; direct writing; passivated metal clusters ID SELF-ASSEMBLED MONOLAYERS; CLUSTER STRUCTURES; NANOSTRUCTURES; FABRICATION; DEPOSITION; TRANSPORT; GRAPHITE AB We have employed thin films of passivated gold nanoclusters, deposited from solution onto a range of surfaces (graphite, silicon, thermally grown silicon dioxide and sputtered silicon dioxide), as a negative tone electron beam resists. The best resolution achieved to date is 26 nm. Response curves obtained for monolayer films on the SiO2 surfaces indicate that the sensitivity depends on the substrate, attributed to backscattering of the primary beam (and secondary electron generation), as confirmed by Monte Carlo simulations. (C) 2001 Elsevier Science BY All rights reserved. C1 Nanoscale Phys Res Lab, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England. Univ Birmingham, Birmingham B15 2TT, W Midlands, England. Sandia Natl Labs, Nanostruct & Adv Mat Dept, Albuquerque, NM 87185 USA. RP Palmer, RE (reprint author), Nanoscale Phys Res Lab, Sch Phys & Astron, Birmingham B15 2TT, W Midlands, England. RI Palmer, Richard/A-5366-2008 OI Palmer, Richard/0000-0001-8728-8083 NR 18 TC 12 Z9 12 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-9317 J9 MICROELECTRON ENG JI Microelectron. Eng. PD SEP PY 2001 VL 57-8 BP 837 EP 841 DI 10.1016/S0167-9317(01)00562-7 PG 5 WC Engineering, Electrical & Electronic; Nanoscience & Nanotechnology; Optics; Physics, Applied SC Engineering; Science & Technology - Other Topics; Optics; Physics GA 473RL UT WOS:000171061800113 ER PT J AU Downing, KH Li, HL AF Downing, KH Li, HL TI Accurate recording and measurement of electron diffraction data in structural and difference Fourier studies of proteins SO MICROSCOPY AND MICROANALYSIS LA English DT Article DE protein structure; electron crystallography; electron diffraction; difference Fourier; tubulin; ligand binding ID PURPLE MEMBRANE; LOW-TEMPERATURE; CCD CAMERA; CRYSTALLOGRAPHY; BACTERIORHODOPSIN; RESOLUTION; INTERMEDIATE; PATTERNS; CRYSTALS AB Many of the techniques that have been developed in X-ray crystallography are being applied in electron crystallographic studies of proteins. Electron crystallography has the advantage of measuring structure factor phases directly from high resolution images with an accuracy substantially higher than is common in X-ray crystallography. However, electron diffraction amplitudes are often not as precise as those obtained in X-ray work. We discuss here some approaches to maximizing the reliability of the diffraction amplitudes through choice of exposure and data processing schemes. With accurate measurement of diffraction data, Fourier difference methods can be used in electron crystallographic studies of small, localized changes of proteins that exist in two-dimensional crystals. The mathematical basis for the power of these methods in detecting small changes is reviewed. We then discuss several issues related to optimizing the quality of the diffraction data and derive an expression for the best exposure for recording diffraction patterns. An application of Fourier difference maps in localizing drug binding sites on the protein tubulin is discussed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Donner Lab, Berkeley, CA 94720 USA. RP Downing, KH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Donner Lab, Berkeley, CA 94720 USA. NR 23 TC 9 Z9 9 U1 0 U2 0 PU SPRINGER-VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1431-9276 J9 MICROSC MICROANAL JI Microsc. microanal. PD SEP-OCT PY 2001 VL 7 IS 5 BP 407 EP 417 DI 10.1017/S1431927601010406 PG 11 WC Materials Science, Multidisciplinary; Microscopy SC Materials Science; Microscopy GA 479PM UT WOS:000171412800002 ER PT J AU Finsterle, S Trautz, RC AF Finsterle, S Trautz, RC TI Numerical modeling of seepage into underground openings SO MINING ENGINEERING LA English DT Article AB Numerical modeling studies were performed to investigate water seepage into underground openings excavated in unsaturated fractured rock. Water seepage is an important factor affecting the performance of a nuclear waste repository, such as the one proposed at Yucca Mountain, NV The amount of water dripping into an underground opening depends on the connectivity and permeability of the fracture network, as well as on the capillarity of individual fractures intersecting the opening. A high-resolution numerical model of an unsaturated fracture network was developed, and the appropriateness of seepage predictions using a fracture-continuum model was examined. Model calibrations to liquid-release tests performed al Yucca Mountain are also discussed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Finsterle, S (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RI Finsterle, Stefan/A-8360-2009 OI Finsterle, Stefan/0000-0002-4446-9906 NR 9 TC 5 Z9 5 U1 0 U2 0 PU SOC MINING METALLURGY EXPLORATION INC PI LITTLETON PA 8307 SHAFFER PARKWAY, LITTLETON, CO 80127 USA SN 0026-5187 J9 MIN ENG-LITTLETON JI Mining Eng. PD SEP PY 2001 VL 53 IS 9 BP 52 EP 56 PG 5 WC Mining & Mineral Processing SC Mining & Mineral Processing GA 473FN UT WOS:000171030000025 ER PT J AU Helfenbein, KG Brown, WM Boore, JL AF Helfenbein, KG Brown, WM Boore, JL TI The complete mitochondrial genome of the articulate brachiopod Terebratalia transversa SO MOLECULAR BIOLOGY AND EVOLUTION LA English DT Article DE Terebratalia transversa; mitochondria; genome; evolution; codon usage; nucleotide skew ID COMPLETE DNA-SEQUENCE; SYNONYMOUS CODON CHOICE; TRANSFER-RNA GENES; NUCLEOTIDE COMPOSITION; RESPECTIVE CODONS; ESCHERICHIA-COLI; PROTEIN GENES; EVOLUTION; ORGANIZATION; ALBINARIA AB We sequenced the complete mitochondrial DNA (mtDNA) of the articulate brachiopod Terebratalia transversa. The circular genome is 14,291 bp in size, relatively small compared with other published metazoan mtDNAs. The 37 genes commonly found in animal mtDNA are present; the size decrease is due to the truncation of several tRNA, rRNA, and protein genes, to some nucleotide overlaps, and to a paucity of noncoding nucleotides. Although the gene arrangement differs radically from those reported for other metazoans, some gene junctions are shared with two other articulate brachiopods, Laqueus rubellus and Terebratulina retusa. All genes in the T. transversa mtDNA, unlike those in most metazoan mtDNAs reported, are encoded by the same strand. The A+T content (59.1%) is low for a metazoan mtDNA, and there is a high propensity for homopolymer runs and a strong base-com positional strand bias. The coding strand is quite G+T-rich, a skew that is shared by the confamilial (laqueid) species L. rubellus but is the opposite of that found in T. retusa, a cancellothyridid. These compositional skews are strongly reflected in the codon usage patterns and the amino acid compositions of the mitochondrial proteins, with markedly different usages being observed between T. retusa and the two laqueids. This observation, plus the similarity of the laqueid noncoding regions to the reverse complement of the noncoding region of the cancellothyridid, suggests that an inversion that resulted in a reversal in the direction of first-strand replication has occurred in one of the two lineages. In addition to the presence of one noncoding region in T. transversa that is comparable with those in the other brachiopod mtDNAs, there are two others with the potential to form secondary structures; one or both of these may be involved in the process of transcript cleavage. C1 DOE Joint Genome Inst, Walnut Creek, CA 94598 USA. Lawrence Livermore Natl Lab, Walnut Creek, CA USA. Univ Michigan, Dept Biol, Ann Arbor, MI 48109 USA. RP Helfenbein, KG (reprint author), DOE Joint Genome Inst, 2800 Mitchell Dr, Walnut Creek, CA 94598 USA. NR 36 TC 63 Z9 69 U1 0 U2 3 PU SOC MOLECULAR BIOLOGY EVOLUTION PI LAWRENCE PA PO BOX 1897, LAWRENCE, KS 66044-8897 USA SN 0737-4038 J9 MOL BIOL EVOL JI Mol. Biol. Evol. PD SEP PY 2001 VL 18 IS 9 BP 1734 EP 1744 PG 11 WC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Evolutionary Biology; Genetics & Heredity GA 466DU UT WOS:000170629700011 PM 11504853 ER PT J AU da Silva, AC Barbosa, D Liddle, AR Thomas, PA AF da Silva, AC Barbosa, D Liddle, AR Thomas, PA TI Hydrodynamical simulations of the Sunyaev-Zel'dovich effect: the kinetic effect SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE galaxies : clusters : general; cosmic microwave background ID MICROWAVE BACKGROUND ANISOTROPIES; INHOMOGENEOUS REIONIZATION; CLUSTER EVOLUTION; POWER SPECTRUM; GALAXIES; FLUCTUATIONS; IMPRINT; GAS AB We use hydrodynamical N-body simulations to study the kinetic Sunyaev-Zel'dovich effect. We construct sets of maps, one square degree in size, in three different cosmological models. We confirm earlier calculations that on the scales studied the kinetic effect is much smaller than the thermal (except close to the thermal null point), with an rms dispersion smaller by about a factor of 5 in the Rayleigh-Jeans region. We study the redshift dependence of the rms distortion and the pixel distribution at the present epoch. We compute the angular power spectra of the maps, including their redshift dependence, and compare them with the thermal Sunyaev-Zel'dovich effect and with the expected cosmic microwave background anisotropy spectrum as well as with determinations by other authors. We correlate the kinetic effect with the thermal effect both pixel-by-pixel and for identified thermal sources in the maps to assess the extent to which the kinetic effect is enhanced in locations of strong thermal signal. C1 Univ Sussex, Ctr Astron, Brighton BN1 9QJ, E Sussex, England. Lawrence Berkeley Lab, Astrophys Grp, Berkeley, CA 94710 USA. Inst Super Tecn, CENTRA, P-1049001 Lisbon, Portugal. RP da Silva, AC (reprint author), Univ Sussex, Ctr Astron, Brighton BN1 9QJ, E Sussex, England. RI Liddle, James/A-4867-2013; Da Silva, Antonio/A-2693-2010; OI Liddle, James/0000-0002-2508-7910; Da Silva, Antonio/0000-0002-6385-1609; Barbosa, Domingos/0000-0002-5191-7826; Thomas, Peter/0000-0001-6888-6483 NR 44 TC 34 Z9 34 U1 0 U2 0 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD OX2 0NE, OXON, ENGLAND SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD SEP 1 PY 2001 VL 326 IS 1 BP 155 EP 163 DI 10.1046/j.1365-8711.2001.04580.x PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 473BK UT WOS:000171019300018 ER PT J AU Terminello, LJ Caturla, MJ Fluss, MJ Gouder, T Haire, RG Haschke, JM Hecker, SS Lander, GH Muller, I Nitsche, H Rebizant, J Schwartz, AJ Silva, RJ Wall, MA Wastin, F Weber, WJ Wirth, BD Wolfer, WG AF Terminello, LJ Caturla, MJ Fluss, MJ Gouder, T Haire, RG Haschke, JM Hecker, SS Lander, GH Muller, I Nitsche, H Rebizant, J Schwartz, AJ Silva, RJ Wall, MA Wastin, F Weber, WJ Wirth, BD Wolfer, WG TI Challenges in plutonium and actinide materials science SO MRS BULLETIN LA English DT Editorial Material C1 Lawrence Livermore Natl Lab, Div Mat Sci & Technol, Livermore, CA 94550 USA. Univ Calif Davis, Dept Appl Sci, Davis, CA 95616 USA. RP Terminello, LJ (reprint author), Lawrence Livermore Natl Lab, Div Mat Sci & Technol, Livermore, CA 94550 USA. RI Weber, William/A-4177-2008; Caturla, Maria /D-6241-2012; Wirth, Brian/O-4878-2015 OI Weber, William/0000-0002-9017-7365; Caturla, Maria /0000-0002-4809-6553; Wirth, Brian/0000-0002-0395-0285 NR 13 TC 4 Z9 4 U1 0 U2 10 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 USA SN 0883-7694 J9 MRS BULL JI MRS Bull. PD SEP PY 2001 VL 26 IS 9 BP 667 EP 671 DI 10.1557/mrs2001.175 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA 478BU UT WOS:000171323700014 ER PT J AU Wu, GH Datar, RH Hansen, KM Thundat, T Cote, RJ Majumdar, A AF Wu, GH Datar, RH Hansen, KM Thundat, T Cote, RJ Majumdar, A TI Bioassay of prostate-specific antigen (PSA) using microcantilevers SO NATURE BIOTECHNOLOGY LA English DT Article ID BIOSENSOR; PROTEIN; ALPHA-1-ANTICHYMOTRYPSIN; IMMUNOSENSOR; IMMUNOASSAYS; BINDING; CANCER; ARRAYS AB Diagnosis and monitoring of complex diseases such as cancer require quantitative detection of multiple proteins. Recent work has shown that when specific biomolecular binding occurs on one surface of a microcantilever beam, intermolecular nanomechanics bend the cantilever, which can be optically detected. Although this label-free technique readily lends itself to formation of microcantilever arrays, what has remained unclear is the technologically critical issue of whether it is sufficiently specific and sensitive to detect disease-related proteins at clinically relevant conditions and concentrations. As an example, we report here that microcantilevers of different geometries have been used to detect two forms of prostate-specific antigen (PSA) over a wide range of concentrations from 0.2 ng/ml to 60 mug/ml in a background of human serum albumin (HSA) and human plasminogen (HP) at 1 mg/ml, making this a clinically relevant diagnostic technique for prostate cancer. Because cantilever motion originates from the free-energy change induced by specific biomolecular binding, this technique may offer a common platform for high-throughput label-free analysis of protein-protein binding, DNA hybridization, and DNA-protein interactions, as well as drug discovery. C1 Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. Univ So Calif, Dept Pathol, Los Angeles, CA 90033 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Majumdar, A (reprint author), Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. FU NCI NIH HHS [R21 CA86132] NR 31 TC 684 Z9 699 U1 11 U2 130 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1087-0156 J9 NAT BIOTECHNOL JI Nat. Biotechnol. PD SEP PY 2001 VL 19 IS 9 BP 856 EP 860 DI 10.1038/nbt0901-856 PG 5 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 468TJ UT WOS:000170774000025 PM 11533645 ER PT J AU Muthuswamy, SK Li, DM Lelievre, S Bissell, MJ Brugge, JS AF Muthuswamy, SK Li, DM Lelievre, S Bissell, MJ Brugge, JS TI ErbB2, but not ErbB1, reinitiates proliferation and induces luminal repopulation in epithelial acini SO NATURE CELL BIOLOGY LA English DT Article ID C-HA-RAS; SIGNALING NETWORK; GROWTH-FACTOR; 3-DIMENSIONAL CULTURE; RECEPTOR INTERACTIONS; PROTEIN CAUSES; CELL SURVIVAL; EGF RECEPTOR; MDCK CELLS; IN-VITRO AB Both ErbB1 and ErbB2 are overexpressed or amplified in breast tumours. To examine the effects of activating ErbB receptors in a context that mimics polarized epithelial cells in vivo, we activated ErbB1 and ErbB2 homodimers in preformed, growth-arrested mammary acini cultured in three-dimensional basement membrane gels. Activation of ErbB2, but not that of ErbB1, led to a reinitiation of cell proliferation and altered the properties of mammary acinar structures. These altered structures share several properties with early-stage tumours, including a loss of proliferative suppression, an absence of lumen, retention of the basement membrane and a lack of invasive properties. ErbB2 activation also disrupted tight junctions and the cell polarity of polarized epithelia, whereas ErbB1 activation did not have any effect. Our results indicate that ErbB receptors differ in their ability to induce early stages of mammary carcinogenesis in vitro and this three-dimensional model system can reveal biological activities of oncogenes that cannot be examined in vitro in standard transformation assays. C1 Harvard Univ, Sch Med, Dept Cell Biol, Boston, MA 02115 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Brugge, JS (reprint author), Cold Spring Harbor Labs, Cold Spring Harbor, NY 11724 USA. FU NCI NIH HHS [U54 CA143836, R01 CA057621, R01 CA057621-07, R01 CA064786, R01 CA064786-05, U01 CA143233, U01 CA143233-01, U54 CA112970, U54 CA112970-01, U54 CA126552, U54 CA126552-01, U54 CA143836-01] NR 48 TC 394 Z9 399 U1 1 U2 11 PU MACMILLAN PUBLISHERS LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 1465-7392 J9 NAT CELL BIOL JI Nat. Cell Biol. PD SEP PY 2001 VL 3 IS 9 BP 785 EP 792 DI 10.1038/ncb0901-785 PG 8 WC Cell Biology SC Cell Biology GA 472JC UT WOS:000170979600011 PM 11533657 ER PT J AU Mohrs, M Blankespoor, CM Wang, ZE Loots, GG Afzal, V Hadeiba, H Shinkai, K Rubin, EM Locksley, RM AF Mohrs, M Blankespoor, CM Wang, ZE Loots, GG Afzal, V Hadeiba, H Shinkai, K Rubin, EM Locksley, RM TI Deletion of a coordinate regulator of type 2 cytokine expression in mice SO NATURE IMMUNOLOGY LA English DT Article ID CELL-SPECIFIC DEMETHYLATION; TRANSCRIPTION FACTOR; GENE-EXPRESSION; CUTTING EDGE; MAST-CELLS; T-CELLS; INTERLEUKIN-4 PROMOTER; LINEAGE COMMITMENT; CHAIN ENHANCER; TH1 CELLS AB Mechanisms that underlie the patterning of cytokine expression in T helper (T-H) cell subsets remain incompletely defined. An evolutionarily conserved similar to 400.bp noncoding sequence in the intergenic region between the genes Il4 and III3, designated conserved noncoding sequence I (CNS-1), was deleted in mice. The capacity to develop T(H)2 cells was compromised in vitro and in vivo in the absence of CNS-1. Despite the profound effect in T cells, mast cells from CNS-1(-/-) mice maintained their capacity to produce interleukin 4. AT cell-specific element critical for the optimal expression of type 2 cytokines may represent the evolution of a regulatory sequence exploited by adaptive immunity. C1 Univ Calif San Francisco, Howard Hughes Med Inst, San Francisco, CA 94143 USA. Univ Calif San Francisco, Dept Med, San Francisco, CA 94143 USA. Univ Calif San Francisco, Dept Microbiol Immunol, San Francisco, CA 94143 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Genome Sci Dept, Berkeley, CA 94720 USA. RP Locksley, RM (reprint author), Univ Calif San Francisco, Howard Hughes Med Inst, San Francisco, CA 94143 USA. FU NHLBI NIH HHS [HL56385, HL66671]; NIAID NIH HHS [AI30663]; NIGMS NIH HHS [GM07618] NR 49 TC 130 Z9 131 U1 0 U2 2 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1529-2908 J9 NAT IMMUNOL JI Nat. Immunol. PD SEP PY 2001 VL 2 IS 9 BP 842 EP 847 DI 10.1038/ni0901-842 PG 6 WC Immunology SC Immunology GA 468WM UT WOS:000170781200024 PM 11526400 ER PT J AU Lee, JY Kwak, JE Moon, J Eom, SH Liong, EC Pedelacq, JD Berendzen, J Suh, SW AF Lee, JY Kwak, JE Moon, J Eom, SH Liong, EC Pedelacq, JD Berendzen, J Suh, SW TI Crystal structure and functional analysis of the SurE protein identify a novel phosphatase family SO NATURE STRUCTURAL BIOLOGY LA English DT Article ID STATIONARY-PHASE SURVIVAL; ESCHERICHIA-COLI; ACID-PHOSPHATASE; SEQUENCE; IDENTIFICATION; MOLSCRIPT; VANADATE; CLONING; PCM AB Homologs of the Escherichia coli surE gene are present in many eubacteria and archaea. Despite the evolutionary conservation, little information is available on the structure and function of their gene products. We have determined the crystal structure of the SurE protein from Thermotoga maritima. The structure reveals the dimeric arrangement of the subunits and an active site around a bound metal ion. We also demonstrate that the SurE protein exhibits a divalent metal ion-dependent phosphatase activity that is inhibited by vanadate or tungstate. In the vanadate- and tungstate-complexed structures, the inhibitors bind adjacent to the divalent metal ion. Our structural and functional analyses identify the SurE proteins as a novel family of metal ion-dependent phosphatases. C1 Seoul Natl Univ, Sch Chem & Mol Engn, Coll Nat Sci, Seoul 151742, South Korea. Kwangju Inst Sci & Technol, Dept Life Sci, Kwangju 500712, South Korea. Los Alamos Natl Lab, Biophys Grp, Los Alamos, NM 87545 USA. RP Suh, SW (reprint author), Seoul Natl Univ, Sch Chem & Mol Engn, Coll Nat Sci, Seoul 151742, South Korea. RI Pedelacq, Jean-Denis/C-6053-2011; Suh, Se Won/H-8306-2013 OI Suh, Se Won/0000-0002-1768-4635 NR 27 TC 28 Z9 29 U1 0 U2 1 PU NATURE AMERICA INC PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 USA SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD SEP PY 2001 VL 8 IS 9 BP 789 EP 794 DI 10.1038/nsb0901-789 PG 6 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA 467UY UT WOS:000170723200020 PM 11524683 ER PT J AU Jackson, DA Doctor, SR Schuster, G Simonen, F AF Jackson, DA Doctor, SR Schuster, G Simonen, F TI Developing a generalized flaw distribution for reactor pressure vessels SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 27th Water Reactor Safety Information Meeting (WRSM) CY OCT 25-27, 1999 CL BETHESDA, MARYLAND AB The US Nuclear Regulatory Commission (NRC) is re-evaluating the guidance and criteria in the code of federal regulations as it relates to reactor vessel integrity, specifically pressurized thermal shock (PTS). Recent ultrasonic examination of considerable vessel material at Pacific Northwest National Laboratory (PNNL) and industry experiences with Yankee Rowe have provided the NRC with a better understanding of PTS issues. The re-evaluation of PTS will consider a risk-informed approach to the PTS rule and also provide important benefits for licensees considering license renewal. Pressurized thermal shock transients can lead to reactor vessel failure. These transients have occurred at operating reactors but, to date, they have not resulted in vessel failure. To properly determine the potential or probability for vessel failure from a PTS event, an accurate estimate of fabrication flaws is necessary. The characteristics of the fabrication flaw are inputs to fracture mechanics structural calculations that will determine the probability of vessel failure during a PTS event. Also, the results will indicate the sizes and locations of flaws that are most likely to cause failures. This information is also an integral input to the overall pressure vessel safety program. In order to obtain an accurate estimate of fabrication flaws to address PTS events for all classes of reactors, a generic flaw distribution must be developed. An expert judgment process will be used in conjunction with empirical data from PNNL, reactor pressure vessel studies and modeling (RR- PRODIGAL Code) in developing generalized flaw distributions. This paper will demonstrate the important relationship between reactor vessel integrity and flaw distributions in reactor pressure vessel material, discuss the PNNL work to date on developing flaw density and distributions for domestic RPVs, and describe the expert judgment process that was used to verify that a generalized flaw distribution can be properly developed and then assist in developing a generalized flaw distribution. (C) 2001 Published by Elsevier Science B.V. C1 US Nucl Regulatory Commiss, Off Nucl Regulatory Res, Div Engn Technol, TWFN, Washington, DC 20555 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. RP Jackson, DA (reprint author), US Nucl Regulatory Commiss, Off Nucl Regulatory Res, Div Engn Technol, TWFN, 10 E42,10,E10, Washington, DC 20555 USA. NR 14 TC 5 Z9 5 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD SEP PY 2001 VL 208 IS 2 BP 123 EP 131 DI 10.1016/S0029-5493(01)00371-5 PG 9 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 469MR UT WOS:000170819900002 ER PT J AU Simonen, FA Khaleel, MA Phan, HK Harris, DO Dedhia, DD Kalinousky, DN Shaukat, SK AF Simonen, FA Khaleel, MA Phan, HK Harris, DO Dedhia, DD Kalinousky, DN Shaukat, SK TI Evaluation of environmental effects on fatigue life of piping SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article; Proceedings Paper CT 27th Water Reactor Safety Information Meeting (WRSM) CY OCT 25-27, 1999 CL BETHESDA, MARYLAND AB Recent data indicate that the effects of light water reactor environments can significantly reduce the fatigue resistance of materials, and show that design fatigue curves may not be conservative for reactor coolant environments. Using revised fatigue curves developed by Argonne National Laboratory (ANL), the work of this paper calculates the expected probabilities of fatigue failures and associated core damage frequencies at a 40-year and 60-year plant life for a sample of components from five PWR and two BWR plants. These calculations were made possible by the development of an enhanced version of the pc-PRAISE probabilistic fracture mechanics code that has the ability to simulate the initiation of fatigue cracks followed by the linking of these cracks. Results of interim calculations subject to review are presented. Components with the highest probabilities of failure can have predicted frequencies of through-wall cracks in the order of about 5 x 10(-2) per year. The corresponding maximum contributions to core damage frequencies are in the order of 10(-6) per year. Components with the very high failure rates show essentially no increase in calculated core damage frequency from 40 to 60 years. (C) 2001 Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. Engn Mech Technol Inc, San Jose, CA 95118 USA. US Nucl Regulatory Commiss, Washington, DC 20555 USA. RP Simonen, FA (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. OI khaleel, mohammad/0000-0001-7048-0749 NR 15 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD SEP PY 2001 VL 208 IS 2 BP 143 EP 165 DI 10.1016/S0029-5493(01)00373-9 PG 23 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 469MR UT WOS:000170819900004 ER EF